Copper metabolism disorders (Wilson's disease): clinical guidelines

List of Abbreviations

ALT — alanine aminotransferase

AST — aspartate aminotransferase

ATPase — adenosine triphosphatase

WD — Wilson's disease

GGT — gamma-glutamyl transferase

INR — international normalized ratio

OLT — orthotopic liver transplantation

PI — prothrombin index

US — ultrasound

ALP — alkaline phosphatase

MRI — magnetic resonance imaging

EEG — electroencephalography

CNS — central nervous system

Terms and Definitions

Chelating therapy (copper-chelating therapy) is a treatment method involving the administration of drugs that bind and eliminate heavy metal ions (such as copper) from the body.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Wilson's disease (WD) (synonyms: Wilson-Konovalov disease, hepatolenticular degeneration, hepatocerebral dystrophy) is a rare, severe, hereditary multisystem disorder characterized predominantly by hepatic, neurological, and psychiatric disturbances resulting from excessive copper deposition in organs and tissues [1]. This disease is among the difficult-to-diagnose conditions due to a prolonged latent course and polymorphism of clinical symptoms. WD can clinically manifest in childhood, adolescence, or at an older age. In the absence of copper-eliminating therapy, the disease is fatal.

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

WD develops when an individual carries pathogenic variants in a compound heterozygous (more often) or homozygous (less often) state in the ATP7B gene, which is located on the long arm of chromosome 13 (13q14.3-q21.1) and consists of 21 exons and 20 introns (the total genomic length of the gene is about 80 thousand base pairs).

The ATP7B gene encodes the copper-transporting protein of the same name from the P-type ATPase group, which is localized in the trans-Golgi network. Dysfunctions of the ATP7B protein resulting from a mutation in the ATP7B gene are accompanied by impaired biliary copper excretion and its accumulation first in the liver and subsequently in other tissues, especially the central nervous system, kidneys, or cornea. Another consequence of ATP7B transporter protein dysfunction is impaired copper transfer from apo- to holoceruloplasmin (the main circulating copper carrier in the human body), leading to protein instability and reduced copper availability for cellular metabolic processes [153, 154].

The highest expression of the ATP7B gene is observed in the liver, but it is also expressed in the kidneys, placenta, mammary glands, brain, and lungs.

The inheritance pattern of WD is autosomal recessive. To date, more than 700 pathogenic variants have been described in the ATP7B gene [88], the majority of which are missense, although nonsense, insertion/deletion, and splice-site mutations also occur [13, 14]. The most common pathogenic variant in the ATP7B gene among Caucasians is H1069Q. About 50–80% of WD patients living in Central, Eastern, and Northern Europe carry at least one allele with this variant. According to several researchers, in Russia among patients with a confirmed diagnosis of WD, the proportion of patients with the H1069Q variant in a heterozygous state is 50%, and the proportion of patients with this variant in a homozygous state is 26.3% [17]. Currently, no clear correlations between pathogenic variants and WD phenotypes are known.

Copper is an essential trace element and a cofactor for several enzymes; in terms of total content in the human body, it ranks third among transition metals indispensable for the organism. It regulates cellular processes and acts as a regulator of cellular signaling pathways, participating in many physiological processes including energy metabolism, antioxidant defense, and iron metabolism. Copper-containing metallothioneins include Cu/Zn superoxide dismutase, cytochrome c oxidase, dopamine beta-hydroxylase, and lysyl oxidase; the latter plays an important role in collagen cross-linking in the extracellular matrix and connective tissue [155, 156].

The physiological requirement for copper is 0.9 to 1.7 mg/day for adults, and 0.5 to 1.0 mg/day for children depending on the age group [18, 155]. The upper tolerable intake level is 5 mg/day. Copper enters the body primarily through food. The amount of copper entering the body exceeding the organism's requirement is normally excreted via bile to maintain copper homeostasis. Between 20% (at an intake >5 mg/day) and 50% (at an intake <1 mg/day) of copper is absorbed in the proximal small intestine, with the remainder excreted in feces. In the blood, absorbed copper binds to albumin and transcuperin and is transported via the portal vein to the liver [155].

Liver, mollusks, crabs, shrimp, oysters, lobsters, soybeans, chocolate, nuts, and cereals are particularly rich in copper.

Decreased function of copper-transporting ATPase resulting from pathogenic variants in the ATP7B gene in a compound heterozygous or homozygous state leads to impaired hepatobiliary copper excretion and impaired incorporation of copper into ceruloplasmin. Because the half-life of apoceruloplasmin is significantly shorter than that of copper-loaded ceruloplasmin (5 hours vs. 5.5 days), WD is typically characterized by decreased blood ceruloplasmin levels. However, in approximately one-third of patients with WD, blood ceruloplasmin levels may fall within the normal range. It should be noted that using the copper-dependent oxidase activity assay allows for a more accurate determination of apoceruloplasmin content, whereas immunological tests may overestimate the obtained values because they cannot differentiate between apo- and holoceruloplasmin.

The primary consequence of copper-transporting ATPase deficiency is the accumulation of copper in various organs and tissues: initially in the liver, and as the disease progresses and in the absence of treatment when the liver's capacity to store copper is exhausted, in the brain, corneas, and kidneys. This accounts for the polymorphism of clinical manifestations of WD. Copper accumulation in parenchymal organs is accompanied by a decrease in serum total copper, since normally about 90% of total copper is bound to ceruloplasmin.

Despite the crucial role of copper in many physiological processes, its excess is detrimental to the organism. The pathogenic effects of excess intracellular copper are mediated by the generation of free radicals leading to lipid peroxidation, damage to proteins, nucleic acids, and mitochondria, combined with the depletion of antioxidant systems. Copper can also inhibit the function of many proteins by directly binding to their thiol and amino groups. In addition, excess copper activates pro-apoptotic mechanisms. All of this ultimately leads to the destruction of copper-overloaded cells, predominantly hepatocytes. Lysis of such hepatocytes results in elevated free serum copper and, consequently, a compensatory increase in its daily urinary excretion and accumulation in other target organs [19]. Furthermore, excess free copper in the serum can lead to hemolytic crises [4].

Intracellular copper overload induces the production of reactive oxygen species, leading to oxidative stress, which is accompanied by changes in mitochondrial membrane permeability, DNA damage, and increased expression of pro-apoptotic proteins, and subsequently induces apoptosis [157, 158].

1.3 Epidemiology of the Disease or Condition

Wilson's disease is a rare (orphan) disorder, although prevalence rates vary across studies. According to a number of studies, its prevalence is approximately 1 case per 7,000–10,000 population, while the carrier frequency of pathogenic variants in ATP7B is about 1:40 [20, 21].

The most frequently cited prevalence is 1:30,000 [21, 22, 23, 24, 140]. More recent studies from China [141] and France [142] indicate a lower prevalence of 1:56,000 and 1:66,000, respectively.

According to data from the federal register of orphan diseases, a total of only 572 and 602 patients diagnosed with Wilson's disease were registered in Russia in 2014 and 2015, accounting for 0.39 and 0.41 per 100,000 population, respectively (children accounted for 16.9% of these) [25]. The true prevalence of the disease is suspected to be higher.

Although over 700 mutations in the ATP7B gene have been found to cause Wilson's disease, the H1069Q missense mutation is the most common (50–80%) among the European and American populations, whereas the R778L mutation is more common (14–49%) in East Asian countries.

Data on the clinical prevalence of Wilson's disease are lacking, but the global genetic prevalence is estimated to be approximately 1:7,026. Heterozygosity in the UK is projected to be 2.5% of the total population. According to published data from the Euro Wilson database, 415 new cases were registered between 2005 and 2009, with approximately half of them under the age of 18 [20].

The significant discrepancy between the number of clinically diagnosed Wilson's disease cases and the estimated genetic prevalence may be due to genetic phenotypic heterogeneity and/or a low diagnosis rate, particularly in the pediatric age group, where children exhibit subtle neuropsychiatric signs and symptoms, yet Wilson's disease is not considered in the differential diagnosis. This review will discuss recent advances in the diagnosis and management of Wilson's disease, with a primary focus on neuropsychiatric signs and symptoms in children with Wilson's disease.

In Russia, among patients with a confirmed diagnosis of Wilson's disease, the proportion of patients heterozygous for the H1069Q variant is 50%, while the proportion of patients homozygous for this variant is 26.3% [17].

1.4 Features of Coding the Disease or Condition

E83.0 – Disorders of copper metabolism.

1.5 Classification of the disease or condition

The clinical presentation of Wilson's disease is characterized by high polymorphism regarding both neurological and somatic manifestations. This is reflected in various classifications of the disease [26, 27]. Currently, the classification of Wilson's disease based on the clinical and pathomorphological principle is most commonly used [28]. The following forms of Wilson's disease are distinguished.

• Asymptomatic form (about 10% of cases): no clinical manifestations, diagnosis established before the onset of symptoms.

• Abdominal (hepatic) form (about 40% of cases): early onset, predominantly presenting with acute liver failure or signs of chronic liver failure; fulminant liver failure, liver cirrhosis.

• Cerebral (neurological) form (about 40–50% of cases): characterized by various extrapyramidal disorders (tremor of the limbs and head, dystonia, cerebellar ataxia, parkinsonism, handwriting disturbance, dysarthria, muscle rigidity, chorea, athetosis), psychiatric disorders (depression, irritability, behavioral disinhibition, psychotic episodes).

• Mixed form: a combination of neurological and hepatic manifestations.

1.6 Clinical presentation of the disease or condition

The clinical presentation of Wilson's disease is characterized by a diversity of symptoms and manifests between the ages of 3 and 74 years (mean age 13.2 years) [29, 30, 31]. Symptoms of the disease rarely appear under the age of 3 years [2, 7]. Symptoms under the age of 3 years are unusual because copper toxicity takes time to develop in the body. Most children present with overt liver disease, although subtle neurological manifestations may already be present. Hepatic manifestations are most common in children, although some (4–6%) may present with mild neurological symptoms. Older patients (adolescents and adults) often present with neuropsychiatric manifestations with or without liver disease. Furthermore, the diagnosis of Wilson's disease should not be overlooked even in the absence of liver disease.

The fully developed clinical picture of Wilson's disease is due to the excessive accumulation of copper in various organs and tissues and predominantly manifests as symptoms of damage to the liver, central nervous system, eyes, and less commonly the kidneys, bones, heart, and endocrine glands [31, 154, 155, 159, 160].

Neurological symptoms of Wilson's disease manifest later than liver damage, in most cases in the second to third decade of life, but can also appear in childhood under the age of 10 years [32, 33]. Neurological manifestations of Wilson's disease, predominantly extrapyramidal, may develop insidiously or rapidly, and symptom severity often fluctuates, sometimes within the same day. Although neurological disorders are more common in adults, they have also been described in early childhood and may develop in patients with Wilson's disease and liver disease who are non-compliant with diet [161].

The clinical picture most frequently includes dystonia (up to 69%), ataxia (up to 30%), postural-kinetic and intention tremor (up to 90%), parkinsonism (up to 62%), accompanied in later stages by sialorrhea, dysarthria, and dysphagia; chorea (16%), athetosis (14%), epilepsy (6%), and others are less common [3, 32, 89]. Other common neurological manifestations include bradykinesia, facial grimacing, dystonia, tremor, rigidity, intention tremor, urinary incontinence, hyperreflexia, and cognitive impairment [160].

Dystonia in Wilson's disease can affect various parts of the body. As the disease progresses in the absence of treatment, focal or segmental dystonia can evolve into generalized dystonia [89]. Parkinsonism in Wilson's disease is characterized by bradykinesia, rigidity, and postural instability, with these phenomena frequently being symmetrical [90]. Tremor is one of the most frequent neurological manifestations of Wilson's disease. Tremor can be postural, intention, occur at rest, or exhibit all of the above conditions (Holmes tremor) [32]. Cerebellar ataxia is observed in almost 30% of patients with Wilson's disease [91]. Dysarthria is the most frequent neurological symptom of Wilson's disease. Based on the predominant speech impairment characteristic, several types of dysarthria can be distinguished in Wilson's disease, including hypokinetic, pseudobulbar (spastic), hyperkinetic (dystonic), ataxic, and mixed [34]. Dysphagia, defined as difficulty in any phase of swallowing, occurs in approximately 18% of patients with Wilson's disease and in 50% of patients with neurological symptoms [34, 90]. Any phase of the swallowing act may be affected, including oral intake, preparation/chewing, oral transit, and the swallow itself. Dysphagia may result from impaired muscle tone (e.g., in orofacial dystonia), impaired swallowing coordination, slowness, and muscle weakness. Sialorrhea is one of the most prominent and frequent symptoms of Wilson's disease and is observed in approximately 70% of patients with neurological manifestations. Very often, this is a consequence of dysphagia and/or the inability to retain saliva in the mouth due to orofacial dystonia [34].

In children, early neurological signs of the disease manifest as behavioral disturbances, academic underachievement, difficulties in tasks requiring coordinated hand-eye coordination, fine motor skill deterioration, and changes in handwriting.

The diagnosis of neuropsychiatric manifestations in Wilson's disease is based on the clinical picture and brain imaging results. Unlike adults with musculoskeletal neurological disorders, the signs and symptoms of movement disorders in children are milder, less noticeable, and therefore more difficult to detect. Furthermore, patients/parents may not report these symptoms because the primary focus is on the liver disease. The main motor symptoms described in children are tremor, mild ataxia, and dysarthria with sialorrhea. Rapidly progressive dystonia is very rare. Psychiatric disorders may not be recognized as symptoms of Wilson's disease. They are common in adults, with a quarter of them presenting with symptoms immediately, and almost all developing symptoms over the course of the disease [162, 163].

Brain abnormalities can be detected on MRI in many, although not all, patients with WD. These changes can be observed before the appearance of neurological or hepatic manifestations of the disease, and some of them may resolve after treatment with copper chelators [2, 40, 41, 42].

High signal intensity lesions in the basal ganglia on T1-weighted images typically reflect hepatic involvement in WD, i.e., changes associated with chronic liver disease. High signal intensity lesions on T2-weighted images reflect cerebral involvement in WD, which typically includes changes in the deep gray matter (putamen, caudate nucleus, and thalamus), the white matter of the brain and pons, and atrophy (which has not been reported in children with WD) [2, 16, 43, 44, 45, 46].

Magnetic resonance spectroscopy can detect significant copper accumulation in the brain parenchyma and is a non-invasive imaging method. It reveals metabolic disorders in the brain before structural changes become apparent on MRI, and the use of this imaging method is well described in adults with WD. Pediatric studies have confirmed that this imaging technique detects early neurological changes even with normal MRI and can provide important information for monitoring disease progression [47].

Psychiatric manifestations. Along with behavioral disorders, psychiatric manifestations include disinhibited behavior, depression, anxiety, and psychotic symptoms. Affected children experience a decline in school performance, mood lability, and inappropriate, aggressive behavior. The majority of patients with neurological and/or psychiatric symptoms of WD develop asymptomatic cirrhosis of the liver that runs a long-term course [4, 31, 34].

In adults, psychiatric disorders may present at an early stage, and the most common symptoms include depression, drastic personality changes, aggressiveness, and irritability. In adolescents, these symptoms are often mistaken for normal adolescent behavior or substance abuse. In children, changes can be very subtle and fall under the diagnostic definition of "learning difficulties." In pediatric practice, awareness of the neurological signs and symptoms of WD is low, as these symptoms are generally thought not to appear until adulthood. However, a number of clinical cases indicate that >5% of children with the hepatic form of WD already have neurological disorders and that >15% of patients with WD develop neurological symptoms or signs during childhood [33]. Since most treatments are based on mitigating the progression of liver failure, it is less widely known that neuropsychiatric symptoms can develop or progress despite an excellent biochemical response to treatment. In addition, the neurological form of WD can occur without overt signs of liver damage, and therefore the total number of pediatric patients with WD may be higher than previously assumed.

Symptoms of liver involvement in WD are highly variable. In children, liver disease develops earlier than neurological symptoms. The clinical onset of WD can present as fulminant hepatitis (more common in children and adolescents), manifesting as coagulopathy, encephalopathy, Coombs-negative hemolytic anemia, and hepatic and renal failure [3, 4, 31]. Sometimes the clinical symptoms closely resemble acute viral hepatitis. This variant of the disease leads to nearly 100% mortality without liver transplantation, so such patients must be immediately placed on the liver transplant waiting list.

The clinical presentation of chronic hepatitis in WD is difficult to distinguish from liver damage of other etiologies and leads to cirrhosis in the absence of pathogenetic therapy, which dictates the need to rule out WD in all patients with both acute and chronic hepatic parenchymal disease, with or without signs of cirrhosis. A characteristic feature of chronic hepatitis in WD is a moderate increase in biochemical markers of cytolysis, cholestasis, and bilirubin levels, accompanied by a high degree of structural changes in the hepatic parenchyma on histological examination of liver biopsies. WD can clinically mimic autoimmune hepatitis with elevated serum immunoglobulins and nonspecific autoantibodies; therefore, in patients with autoimmune hepatitis who are unresponsive to corticosteroid therapy, WD should also be ruled out [31].

Liver disease is first detected in 60% of patients with WD across all age groups. It can be completely asymptomatic and discovered incidentally, or it can be accompanied by signs and symptoms of any form of liver disease. Progression can be slow or very rapid. Screening for WD should be part of the workup for any child with liver pathology.

Hepatic manifestations in WD are highly diverse and can range from asymptomatic biochemical abnormalities, complications of chronic diseases, and steatosis to acute hepatitis, acute liver failure (ALF), chronic hepatitis, and cirrhosis [3]. In the early stages, patients may be asymptomatic, but elevated liver enzymes or abnormal liver ultrasound findings may be discovered incidentally. As the disease progresses, patients may develop signs and symptoms of chronic liver disease (e.g., hepatosplenomegaly) or complications of cirrhosis (e.g., ascites and esophageal variceal bleeding). A diagnosis of WD must always be considered in the differential diagnosis for any child or young adult with abnormal liver function tests or clinical signs of non-alcoholic fatty liver disease or autoimmune liver disease [2, 16, 21, 22].

ALF is a severe form of WD characterized by jaundice, hepatitis, hepatomegaly, and coagulopathy, with or without encephalopathy, in previously healthy children. The Pediatric Acute Liver Failure (PALF) study group defines ALF as an INR ≥1.5 in the presence of encephalopathy or an INR ≥2.0 regardless of the presence of encephalopathy [23]. Some children may have a history of hepatitis-like illnesses accompanied by recurrent jaundice, hemolytic anemia, or elevated transaminase levels [4]. Some clinicians view this manifestation as the progression of acute-on-chronic liver failure, since histological examination invariably reveals evidence of pre-existing chronic liver disease. Acute or chronic liver failure is identified in patients with acute hepatitis accompanied by jaundice (total serum bilirubin >5 mg/dL or 85 µmol/L) and coagulopathy (INR >1.5), as well as ascites and/or hepatic encephalopathy within 4 weeks [24]. The distinguishing features of ALF in WD (Wilsonian ALF) from other causes of liver failure include a relatively modest elevation in liver enzymes (AST, ALT) with an AST/ALT ratio typically greater than 2, normal or subnormal alkaline phosphatase (ALP) levels, association with Coombs-negative hemolytic anemia due to high free copper levels leading to high total bilirubin, an ALP-to-total bilirubin ratio generally less than 4, coagulopathy unresponsive to vitamin K therapy, encephalopathy, and renal failure [2, 4, 16, 20].

Common signs and symptoms may include abdominal pain, anorexia, seizures, jaundice, hepatosplenomegaly, ascites, caput medusae, spider angiomas, and upper gastrointestinal bleeding. Jaundice is more pronounced than in other chronic liver diseases, which may be secondary to concomitant intravascular hemolysis in addition to decompensation of liver function.

Liver involvement in WD can mimic non-alcoholic fatty liver disease, autoimmune hepatitis, and/or acute infectious hepatitis.

Histologically, liver cirrhosis is frequently found. Occasionally, completely asymptomatic patients may have biochemical or genetic evidence of WD, which is considered "silent" WD [20].

About 40% of pediatric patients with WD and liver disease have Kayser-Fleischer rings.

Ocular involvement. A pathognomonic symptom of WD is Kayser-Fleischer rings, which are copper deposits in Descemet's membrane of the cornea. In children with asymptomatic and mild hepatic presentations of WD, they are usually not visualized [39]. Kayser-Fleischer rings are detected in 95% of patients with neurological symptoms and in approximately half of patients without neurological disorders [3]. For their reliable identification, a slit-lamp examination must be performed [40, 92]. It should be noted that Kayser-Fleischer rings are not always specific for WD and can form in patients with chronic cholestatic liver diseases or neonatal cholestasis [41, 42]. Other possible ophthalmologic manifestations of WD include anterior subcapsular cataracts (the so-called "sunflower copper cataract"), which are also detected during slit-lamp examination.

Kayser-Fleischer rings develop first superiorly, then inferiorly, and finally in the lateral and medial areas of the cornea. They occur in approximately 50% of patients with hepatic manifestations and in approximately 95% of patients with neurological manifestations. They are reversible and disappear over time with WD treatment [160].

Hemolytic anemia

Coombs-negative hemolytic anemia in patients with WD can present as a single acute episode or have a chronic course. In some cases, this may be the sole presenting symptom of WD. Patients with a history of jaundice prior to the diagnosis of WD most likely experienced previously unrecognized hemolysis.

During pregnancy, female patients with WD may develop acute hepatitis and hemolysis, which requires differential diagnosis with HELLP syndrome.

Involvement of the kidneys, joints, musculoskeletal, cardiovascular, and reproductive systems

In addition to neurological/psychiatric symptoms, other extrahepatic manifestations include:

- bluish discoloration of the nail lunulae;

- hyperpigmentation of the skin of the legs;

- renal tubular dysfunction: uricosuria, glucosuria, aminoaciduria, proteinuria, renal tubular acidosis [35, 36];

- phosphaturia, calciuria, nephrolithiasis;

- premature osteoporosis, arthropathy, chondrocalcinosis [37];

- cardiomyopathy, arrhythmias [38];

- leukopenia, thrombocytopenia (both due to hypersplenism and as a result of therapy);

- pancreatitis, cholelithiasis;

- myopathy;

- hypoparathyroidism;

- dysmenorrhea, infertility, or recurrent miscarriage;

- gigantism.

The main manifestations of WD are presented in Appendix A3.2

2. Diagnostics, medical indications and contraindications for diagnostic methods

The criteria for establishing the diagnosis of WD are:

– decreased serum ceruloplasmin and copper levels,

– Coombs-negative hemolytic anemia,

– increased copper content in liver biopsies,

– increased urinary copper excretion,

– presence of Kayser-Fleischer rings,

– signs of CNS damage and/or MRI abnormalities,

– identified pathogenic variants in the ATP7B gene in a homozygous or compound heterozygous state.

The criteria are evaluated using a diagnostic scoring system based on all available examination methods, approved at the 8th International Leipzig Meeting on Wilson Disease in 2001 — the so-called "Leipzig score" [26] (see Appendix G1). A score of 4 or more establishes the diagnosis.

Screening for WD should be performed in adults and children over 1 year of age with unexplained elevation of serum liver transaminases (alanine aminotransferase and aspartate aminotransferase), manifestations of acute liver failure, chronic hepatitis, liver cirrhosis, neurological or psychopathological disorders of unknown etiology, Coombs-negative hemolytic anemia, or a positive family history of WD.

The diagnosis of WD is based on a combination of clinical symptoms, laboratory data, and molecular genetic testing [3, 4, 31, 152].

In the presence of Kayser-Fleischer rings, reduced ceruloplasmin concentration (<10 mg/dL), and increased 24-hour urinary copper excretion, the diagnosis of WD is unquestionable.

However, in some cases, clinical symptoms may be absent or non-specific, and laboratory values may fall within the normal range, which complicates screening diagnosis of WD and necessitates further in-depth evaluation of patients, including molecular genetic testing to identify pathogenic variants in the ATP7B gene and, if necessary, percutaneous liver biopsy with quantitative copper assessment in biopsy specimens (Appendix A3.3, Appendix A3.4) [4, 12].

2.1 Complaints and Anamnesis

Patients with WD may present with symptoms of gastrointestinal ("hepatological") and central nervous system involvement. When manifesting with liver involvement, patient complaints may include vomiting, general weakness, abdominal distension (due to ascites), leg edema, jaundice, and skin pruritus. In the cerebral form of the disease, patients primarily notice tremor, muscle stiffness, speech problems, personality changes, anxiety, and auditory or visual hallucinations may also occur [29, 31].

When taking the medical history and assessing complaints, it is recommended to pay attention to:

− a positive family history (presence of a family member with a confirmed diagnosis of WD);

− bluish coloration of the nail lunulae, skin hyperpigmentation on the legs;

− recurrent jaundice, ascites;

− sialorrhea (drooling);

− movement disorders: tremor, poor coordination, fine motor impairment, dystonia, parkinsonism (masked facies, muscle rigidity, bradykinesia, gait disturbance), pseudobulbar syndrome;

− psychiatric disorders such as depression, neurosis, anxiety, and intellectual decline.

2.2 Physical Examination

During the physical examination, attention must be paid to the main physical manifestations:

- jaundice of the sclera and skin, mild to moderate hepatomegaly, splenomegaly;

- Kayser-Fleischer ring;

- presence of edema, ascites;

- presence of telangiectasias, prominent abdominal wall veins, palmar erythema;

- movement disorders (tremor, parkinsonism, chorea, dystonia, ataxia), sialorrhea, dysarthria, dysphagia;

- psychiatric symptoms of the disease: depression, anxiety disorders, disinhibited behavior, cognitive impairment, personality changes, psychosis.

For accurate visualization of Kayser-Fleischer rings, biomicroscopy of the eye by an ophthalmologist must be performed. The absence of this sign does not rule out the diagnosis of WD, including in patients with prominent neurological symptoms.

A patient with suspected WD must undergo a neurological examination, paying attention to the presence of extrapyramidal disorders. It is necessary to evaluate the presence, type, and characteristics of tremor, assess muscle tone, and note the presence of bradykinesia, pseudobulbar disorders, cerebellar functions, and gait [89].

2.3 Laboratory Diagnostics

• To ensure timely detection of anemia, leukopenia, and thrombocytopenia, a complete blood count (CBC) with differential is recommended for all patients with suspected WD [3, 31, 42, 44].

(GoR – C, LoE – 5)

Comment: Leukopenia and thrombocytopenia are manifestations of hypersplenism in patients with WD at the cirrhosis stage. In addition, they may develop during penicillamine therapy**.

In some cases, the manifestation of WD is accompanied by acute hemolysis occurring as part of the underlying disease or triggered by infection or medication. Hemolysis is a manifestation of the toxic effects of copper in WD.

This test is also performed to monitor therapeutic efficacy and prevent adverse drug reactions (see sections "3.1.2 Pharmacotherapy" and "5.2 Dispensary Follow-up").

• All patients with suspected WD are recommended to undergo a general biochemical blood test (determination of alanine aminotransferase activity, aspartate aminotransferase activity, total bilirubin level, conjugated (direct) bilirubin level, lipid profile panel [total cholesterol, lipoproteins, low-density lipoprotein cholesterol, triglycerides], alkaline phosphatase activity, gamma-glutamyltransferase activity, total protein, and albumin) to confirm or rule out liver failure [96, 97].

(UCSR – C, UDS – 4)

Comment: in acute WD with liver failure, there is an elevation in total bilirubin (>300 µmol/L, >17.5 mg/dL) with a moderate increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity (100–500 U/L), and low alkaline phosphatase activity (<40 IU/L) [46].

To prognostically assess the severity of hepatic insufficiency, the alkaline phosphatase (in U/L)/total bilirubin (in mg/dL) ratio <2.0 and the AST/ALT ratio >2.2 should be evaluated. The combination of these indices has high diagnostic sensitivity and specificity in life-threatening pathological conditions [46].

• All patients with suspected WD are recommended to have blood creatinine, blood urea, and blood uric acid levels measured to confirm or exclude renal failure [93, 143, 144].

(Level of reliability of evidence – B, Level of conviction of evidence – 3)

• All patients with suspected WD are recommended to undergo serum iron testing, serum transferrin testing, and blood ferritin testing to monitor iron metabolism [93, 143, 144].

(Level of reliability of evidence – B, Level of conviction of evidence – 3)

• All patients are recommended to undergo a coagulogram (exploratory study of the hemostatic system): determination of blood or plasma prothrombin (thromboplastin) time and the international normalized ratio (INR) to monitor liver synthetic function and predict further patient management tactics [3, 4, 31, 122, 123].

(Level of Reliability of Evidence – C, Level of Convincingness of Evidence – 4)

Comment: patients with impaired liver function show a decrease in the prothrombin index (PI) and an increase in the international normalized ratio (INR).

• All patients older than 1 year with suspected WD are recommended to undergo blood ceruloplasmin level testing and, optionally, blood copper level testing / blood copper level testing by atomic absorption spectroscopy to establish the diagnosis of WD [3, 4, 31, 48, 51, 92, 124, 146].

(LoE – A, GoR – 1)

Comment: normally, blood ceruloplasmin levels range from 20 to 40 mg/dL. A ceruloplasmin level <10 mg/dL indicates a high probability of WD [3, 31]. In addition to WD, serum ceruloplasmin may be decreased in heterozygous carriers, protein-losing nephropathy, malabsorption, end-stage liver failure of any etiology, aceruloplasminemia, and Menkes disease (an X-linked disorder of copper transport) [49].

Ceruloplasmin concentration may be elevated in acute inflammation, as well as in hyperestrogenemia, for example, during pregnancy or when taking estrogens [3].

A normal ceruloplasmin level does not rule out Wilson's disease (WD) and requires further diagnostic workup. Among children with a confirmed diagnosis of WD, 20% do not have a reduced ceruloplasmin level [39, 50, 51]. In newborns up to 6 months of age, the physiological concentration of ceruloplasmin in the blood is very low; its level gradually increases with age, peaking higher than in adults during early childhood (approximately 30–50 mg/dL), and then gradually drops to standard values [52]. Testing blood ceruloplasmin levels for WD diagnosis should not be performed before 1 year of age due to its lack of informativeness. Blood copper levels are usually reduced proportionally to the decrease in ceruloplasmin. It should be kept in mind that in acute liver failure caused by WD, copper levels may be markedly elevated (>200 mcg/dL [31.4 µmol/L]) [92]. Total serum copper content (including non-ceruloplasmin-bound copper, or "free copper", as well as copper incorporated into ceruloplasmin) generally decreases proportionally to the decrease in serum ceruloplasmin levels. In WD patients with severe liver damage, serum copper levels may be within the normal range or markedly elevated in the setting of acute liver failure due to copper release from hepatic tissue stores and an increase in free copper in the blood. The concentration of free copper in blood serum can be estimated from total serum copper and ceruloplasmin levels, but this depends on the adequacy of measurement methods for both serum copper and ceruloplasmin. Total serum copper has low diagnostic value, but can be useful for monitoring pharmacotherapy. Very low values may indicate systemic copper deficiency, which can be observed in some patients during prolonged treatment. As a diagnostic criterion for WD in children, serum ceruloplasmin determination is recommended at an age older than 1 year.

However, ceruloplasmin levels can be affected by other liver diseases, malnutrition, and inflammatory conditions, since this protein is mainly synthesized by the liver and functions as an acute-phase reactant. For example, in WD patients with an active infection, serum ceruloplasmin levels may be elevated to normal values, or levels may be low in patients without WD who have protein-losing enteropathy [31, 50, 51].

• In all patients with suspected WD, it is recommended to determine 24-hour urinary copper excretion (urinary copper level test) [12, 48, 125–127].

(LoE – A, GoR – 1)

Comment: in untreated patients, 24-hour urinary copper excretion reflects the amount of free "non-ceruloplasmin" copper in the circulating blood. To accurately determine 24-hour urinary copper excretion, the 24-hour urine volume and urinary creatinine level should be assessed [3]. In cases of renal failure, this test is not applicable. The diagnostically significant threshold for WD is a 24-hour urinary copper excretion level >100 μg/24 hours (1.6 μmol/24 hours); however, in 25% of asymptomatic children with a confirmed diagnosis, 24-hour urinary copper excretion was lower [39, 53]. Even at urinary copper excretion >40 μg/24 hours (0.65 μmol/24 hours), further work-up for WD should be performed (sensitivity 78.9% and specificity 87.9%) [54]. An increase in 24-hour urinary copper excretion is also possible in other liver diseases, as well as in some heterozygous carriers of the WD mutation [3]. Interpretation of 24-hour urinary copper excretion values may be difficult due to overlap with other types of liver disease, especially in acute liver failure or chronic cholestasis of other etiology.

Since urinary copper excretion can also increase in other liver diseases (autoimmune hepatitis, chronic active liver diseases, cholestasis, acute liver failure of another genesis), a provocative test with #penicillamine** in children has been proposed as a means to increase the sensitivity and specificity of determining 24-hour urinary copper excretion. The test consists of taking #penicillamine** at a dose of 1000 mg/day in two doses of 500 mg with a 12-hour interval during the 24-hour urine collection [55]. If data on 24-hour urinary copper excretion are inconclusive, an increase in urinary copper excretion after the #penicillamine** provocative test above 1600 mcg/day makes it possible to speak of WD with greater certainty. The provocative test is standardized only in pediatric patients. This test is rarely used due to its unreliability in ruling out WD in asymptomatic siblings [55].

• In all patients with biochemical and clinical data suggestive of WD, it is recommended to determine gene variants in another or unspecified biological material sample, unclassified in other categories, using Sanger sequencing / high-throughput sequencing / polymerase chain reaction / multiplex ligation-dependent probe amplification methods, if available, in order to confirm the diagnosis [20, 48, 128–130].

(UCSR – C, UDS – 4)

Comment: screening for frequent mutations is possible, and in their absence, complete sequencing of the ATP7B gene, testing using massively parallel sequencing methods (gene panels, exome sequencing, genome sequencing) (complex of tests for the diagnosis of Wilson's disease).

In the absence of pathogenic variants in the gene with highly convincing and characteristic clinical and laboratory data favoring WD, the disease should not be ruled out, since not all pathogenic variants can be detected using standard sequencing methods (deep intronic mutations, large rearrangements, etc.).

(UCSR – C, UDS – 4)

2.4 Instrumental Diagnostics

• All patients with suspected WD are recommended to undergo an ultrasound examination (ultrasound) of the liver, gallbladder, ducts, and spleen (comprehensive abdominal ultrasound) to diagnose hepatobiliary system lesions [56, 57].

(LoE – C, GoR – 5)

Comment: ultrasound may reveal hepatomegaly with diffuse changes in the liver parenchyma in the form of hyperechogenicity and microfocal diffuse heterogeneity. In the presence of cirrhosis, regeneration nodules are visualized in the parenchyma, splenomegaly, dilation of the main portal and splenic veins, and color Doppler mapping signs of portal hypertension.

Ultrasound changes are not specific for WD, so this study is not diagnostically definitive, but it may be useful for the non-invasive assessment of structural changes in the liver and monitoring treatment efficacy.

(CGR – B, LVE – 2)

Comment: this study is useful for a non-invasive assessment of the severity of liver fibrosis in WD. The measurement results should not be relied upon entirely if they contradict clinical data.

• All patients with neurological symptoms characteristic of WD are recommended to undergo brain magnetic resonance imaging (MRI) to detect pathological changes in the brain [4, 60, 92, 131, 132].

(CGR – B, LVE – 3)

Comment: Brain MRI changes are detected in 90% of patients with WD presenting with neurological symptoms, in 40–70% with the abdominal form of WD, and in 20% of patients with the asymptomatic form [89]. The absence of imaging changes in patients with signs of CNS involvement does not rule out a diagnosis of WD. Brain MRI most frequently reveals symmetrical bilateral increased signal intensity on T2-weighted images in the basal ganglia (caudate nucleus, putamen, and globus pallidus), thalami, midbrain (giant panda face sign), and pons. As the disease progresses, signs of a diffuse atrophic process of the brain appear with uniform expansion of the subarachnoid spaces and ventricular system [19, 98, 99]. Changes in the MR signal from brain structures may be absent in 7–17% of children with the mixed form of WD who present with neurological symptoms such as tremor, dysarthria, and extrapyramidal muscle tone changes. At the same time, brain MRI changes may precede the development of neurological symptoms in 10% of WD cases and are reversible with copper-chelating therapy.

Studies may be performed during follow-up monitoring as clinically indicated [100, 101].

Anesthesia is used as indicated.

• Patients with suspected epileptic syndrome are recommended to undergo routine electroencephalography (EEG) for the timely diagnosis and management of epileptic seizures [102, 133].

(UCSR – C, UDS – 4)

Comments: 24-hour video EEG monitoring may also be recommended.

• Patients with suspected WD are recommended an appointment (examination, consultation) with an ophthalmologist and ocular biomicroscopy to detect Kayser-Fleischer rings and/or cataracts [3, 4, 31, 62].

(GoR – C, LoE – 5)

Comment: ophthalmological manifestations in WD include Kayser-Fleischer rings and anterior subcapsular cataracts (so-called "sunflower cataracts"). Kayser-Fleischer rings represent copper deposition on the inner surface of the cornea in Descemet's membrane. Visualization of the Kayser-Fleischer ring is performed during an ophthalmological examination using a slit lamp, sometimes with gonioslenses; in advanced stages of the disease, the ring can be seen with the naked eye. The development of a sunflower cataract is much less common in WD. The cataract does not affect visual acuity and is visualized using a slit lamp as a gray or golden disc on the anterior lens capsule, from which rays radiate toward the lens periphery [3, 4, 31].

(CGR – C, LVE – 5

(UCSR – C, UDS – 4)

Comments: left ventricular or biventricular hypertrophy, early repolarization, ST-segment depression, T-wave inversion, and various arrhythmias may be detected.

2.5 Other Procedures

• When blood ceruloplasmin levels are normal and urinary copper excretion is slightly elevated, for the purpose of differential diagnosis and determining the stage of liver damage, it is recommended to perform a percutaneous liver biopsy (percutaneous liver biopsy, ultrasound-guided liver biopsy) with copper staining and quantitative determination of copper content in liver tissue (percutaneous liver biopsy, ultrasound-guided liver biopsy) with quantitative determination of copper content in liver tissue and histological examination of the biopsy specimen (pathological-anatomical examination of liver puncture biopsy material) to establish a diagnosis [3, 31].

(LoE – C, GoR – 5)

Comment: Can be used when molecular genetic testing results are inconclusive!

The biopsy specimen must be at least 1 cm in length [3, 4, 31].

A liver tissue copper content >250 mcg/g (4 mcmol/g) of dry weight is evidence of WD. Lowering the diagnostic threshold to 70–250 mcg/g (1.2–4 mcmol/g) increases the sensitivity of the method from 83% to 96.5%, while specificity remains quite high at 95.4% and 98.6%, respectively [63]. The main problem with this method is the uneven distribution of copper in the liver tissue, which can lead to underestimated analysis results in case of sampling errors, a factor that should be considered when interpreting results [3, 4, 40, 63, 64, 65]. Liver copper concentration may be elevated in long-standing cholestasis, idiopathic copper toxicosis syndromes, etc.

Morphological changes in the liver in WD are not pathognomonic and include, in early stages, signs of hepatocyte fatty change (macro- and microvesicular), glycogenated nuclei, and focal hepatocellular necrosis, as well as a predominance of minimal and low-grade inflammatory activity combined with a high proportion of advanced fibrotic changes. Fatty degeneration of hepatocytes in WD is likely related to mitochondrial damage due to oxidative stress followed by impaired lipid metabolism, while inflammatory manifestations are associated with lipid peroxidation, free radical formation, and depletion of glutathione stores resulting from excess copper accumulation in hepatocytes. Histological changes in the liver parenchyma mimicking autoimmune hepatitis, viral, alcoholic, and drug-induced liver injury have been described. As parenchymal damage progresses, fibrosis and subsequently cirrhosis of the liver develop. A histological picture of macronodular liver cirrhosis is usually found as an outcome of WD, although cases of micronodular cirrhosis have also been described. Various histochemical staining methods (rhodamine, rubeanic acid, orcein, Timm's sulfide method) are used for the qualitative detection of copper deposits in liver tissue, but all of them have low diagnostic value [65, 66, 67, 68].

(CGR - C; LVE - 5)

(CGR - C; LVE - 5)

(CGR - C; LVE - 5)

Note: Diagnosis and treatment of WD are carried out involving the following specialists (as clinically indicated): pediatrician/general practitioner/family physician, clinical geneticist, gastroenterologist, ophthalmologist, neurologist, psychiatrist, nephrologist, hematologist/pediatric hematologist-oncologist, surgeon/pediatric surgeon, medical psychologist, pulmonologist, etc.

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

3.1 Conservative Treatment

Treatment strategies for WD are aimed at reducing copper levels in the body. This is usually achieved by reducing dietary copper intake, decreasing copper absorption from the gastrointestinal tract using zinc salts, and/or increasing urinary copper excretion using chelating agents, including D-penicillamine and trientine.

Limiting dietary copper intake cannot prevent its accumulation, but excessive consumption of copper-rich foods should be avoided until symptoms resolve and biochemical abnormalities are corrected. The goal of treatment is either to increase urinary or fecal copper excretion or to block intestinal copper absorption. Treatment should be initiated after establishing the diagnosis [31].

3.1.1 Diet Therapy

(LoE – C, GoR – 5)

Comments: foods with a high copper content (liver, shrimp, nuts, chocolate, mushrooms) are restricted. At least during the first year of treatment, copper-free water is used; water purification filters are installed if necessary to control copper levels in tap water, as copper pipes may be used in its delivery. The use of copper utensils for cooking and storing food is prohibited. Vitamin and mineral supplements containing copper must be avoided. Dietary recommendations help slow down disease progression, but cannot be used as the sole line of therapy.

Dietary recommendations are presented in Appendix A3.4.

The mainstay of WD treatment is copper-eliminating therapy, and in cases of resistance to medical treatment, liver transplantation is performed. The entire treatment period can be divided into the initial phase and the maintenance therapy phase. The criterion for switching to maintenance therapy is regression of clinical manifestations (disappearance of ascites, jaundice, normalization of the menstrual cycle, regression of Kayser-Fleischer rings, sustained normalization of biochemical parameters, including copper metabolism, "liver" enzymes, and liver function.

The initial phase of administering copper-chelating therapy at a therapeutic dose lasts at least 2 years.

3.1.2 Drug therapy

• If a patient is diagnosed with WD, it is recommended to prescribe penicillamine^**, with the dose selected individually: in children (according to instructions starting from 3 years of age)—20 mg/kg of body weight, in adults—up to 1500–2000 mg, for the purpose of binding free copper and accelerating its urinary excretion [3, 4, 31, 69, 70, 71].

(GoR – C, LoE – 5)

Comment: is the drug of choice in the treatment of Wilson's disease. Penicillamine^** is a penicillamine derivative whose molecule contains a free sulfhydryl group through which the chelating activity of this drug is exerted. Penicillamine^** mobilizes copper from the liver and other organs and increases its urinary excretion, and also induces the synthesis of metallothioneins. Penicillamine^** is administered 1 hour before meals, because food decreases the intestinal absorption of the drug.

The tolerability of penicillamine** can be improved by starting with a gradual dose increase [3]. The therapeutic dose of penicillamine** in children from 3 years of age (according to instructions) is 20 mg/kg/day. Treatment should be started with half the dose—#penicillamine 10 mg/kg/day depending on age (125-250-500 mg) with a gradual increase of 125-250 mg every 5-7 days until the therapeutic dose is reached [3, 31, 139]. In adults, the initial doses of #penicillamine for therapy are 125-250 mg per day with a gradual (every 4–7 days) increase of 125–250 mg up to the therapeutic dosage of 1000–1500 (up to 2000) mg per day, which can be administered in 2-4 doses (in practice—more often 3-4 doses) [3].

Dose adjustment is performed as daily urinary copper excretion decreases. Therapy is prescribed for life. Patients who discontinue penicillamine** are at risk of developing liver function decompensation.

Adverse reactions to therapy with penicillamine^** develop in approximately 30% of cases. In patients with the mixed (neurological) form of WD, neurological symptoms worsen in 30% of cases, which is associated with the induced high mobilization of copper from the liver and brain. Some WD patients may develop an acute allergic reaction in the form of a rash, fever, or urticaria during therapy. Subacute toxic reactions in the form of proteinuria and bone marrow suppression may develop. Chronic toxic effects on the skin (premature aging, scarring defects), autoimmune diseases (systemic lupus erythematosus, arthritis, elevated antinuclear factor), and reduced resistance to infections may also occur. The use of penicillamine^** leads to pyridoxine deficiency, which requires the prescription of #pyridoxine** at a dose of 25–50 mg/day [3].

With timely and correct treatment, 90% of patients show positive dynamics with the normalization of liver markers within 2–6 months [72].

Contraindications to the use of penicillamine** include hypersensitivity to penicillamine** and other components of the drug, agranulocytosis, renal failure, hematopoiesis disorders, and age under 3 years.

On average, therapy monitoring is carried out 2 times a month during the first year of therapy, and annually thereafter [100, 92].

Treatment monitoring in children is generally carried out more frequently: once a week at the start of therapy (in the first month of treatment) and during the period of increasing the penicillamine** dose, after which laboratory and instrumental studies are performed every 1–3 months until remission occurs, and every 3–6 months thereafter (more frequently as clinically indicated) [12].

Non-compliance with the treatment regimen can lead to a life-threatening condition, so in case of low compliance, the intervals between monitoring studies should be shorter, especially for adolescent patients. Therapy monitoring includes:

- Physical examination (identifying new WD symptoms or the development of adverse reactions to therapy);

- Determination of copper content in 24-hour urine. The target range for urinary copper excretion during maintenance chelation therapy is 200–500 mcg (3–8 mcmol) per day [3, 12, 31];

- General general-medical biochemical blood test (determination of blood alanine aminotransferase activity, blood aspartate aminotransferase activity, total blood bilirubin level, conjugated blood bilirubin level, blood alkaline phosphatase activity, gamma-glutamyltransferase activity, blood creatinine level, blood urea level). Liver parameters normalize within 3–12 months of chelation therapy [31];

- Evaluation of complete blood count (CBC) with differential—monitoring for adverse reactions during therapy. Anemia, neutropenia, and thrombocytopenia may be detected [44];

- To timely detect adverse reactions during chelating therapy (penicillamine**), such as proteinuria, urinalysis should be monitored at least once every 6 months or more frequently as clinically indicated [3, 45];

- Scheduled ophthalmological examination (consultation) annually with biomicroscopy using a slit lamp to monitor Kayser-Fleischer rings. The appearance of Kayser-Fleischer rings and changes in biochemical parameters indicate the need for treatment adjustment or patient non-compliance with the therapeutic regimen;

- Non-invasive instrumental studies, such as comprehensive ultrasound examination of the abdominal cavity at least once every 6–12 months, and liver elastometry at least once every 1–2 years.

(GoR – C, LoE – 5)

Comment: zinc suppresses intestinal copper absorption and is used as an alternative treatment for WD. Zinc preparations induce enterocyte metallothioneins, which have a high affinity for copper and bind it in the intestinal epithelium. Zinc preparations prevent copper absorption into the systemic circulation and promote its excretion in feces. Zinc preparations are less toxic than chelating therapy [73, 74].

Zinc and penicillamine** should not be administered together before the same meal.

The efficacy of zinc therapy should be assessed by clinical and biochemical improvement, and measurement of 24-hour urinary copper and zinc excretion. The level of excreted copper on maintenance therapy should be in the range of 30–75 mcg per day (0.5–1.2 mcmol per day); a 24-hour urinary copper content below 30 mcg indicates drug overdose. Serum zinc and excreted zinc levels should be maintained above 125 mcg/dl and 1.5–2 g/day, respectively [31, 76]. In patients with liver damage, zinc monotherapy is insufficiently effective and should not be used [31].

Possible adverse reactions: gastrointestinal manifestations include gastric mucosal irritation and elevated transaminase activity at the start of treatment. Zinc preparations may have an immunosuppressive effect and reduce leukocyte chemotaxis. An increase in serum lipase and/or amylase activity may occur without clinical manifestations of pancreatitis. Worsening of neurological symptoms during zinc therapy is rare. The safety of high doses of zinc preparations in patients with impaired renal function has not yet been established [78].

• For patients with asymptomatic WD, it is recommended to consider choosing zinc preparations as a first-line treatment under regular dispensary monitoring due to fewer adverse reactions compared to penicillamine** [70, 79, 80, 81, 82, 137].

(CGR – B, LVE – 2)

Comment: when deciding on therapy with zinc preparations (#Zinc sulfate), it should be taken into account that in the presence of clinical manifestations of WD, penicillamine** remains the drug of choice [3, 4, 31]. If clinical manifestations and biochemical changes progress, penicillamine** should be prescribed.

There is a widespread opinion regarding the efficacy of combination therapy with penicillamine** and zinc preparations, but data regarding this perspective are insufficient.

Zinc and penicillamine** should not be administered together before the same meal.

(GoR – C, LoE – 5)

Comments: trientine is no less effective than penicillamine**; it binds and excretes copper in the urine in WD.

The drug may be preferable for WD patients who have severe thrombocytopenia or neutropenia, which can occur with splenomegaly as part of hypersplenism syndrome. Paradoxical neurological deterioration after starting trientine treatment appears to be less common than with penicillamine**, although a direct comparison has never been performed [146].

Trientine has been an effective initial therapy for patients, even with initially decompensated liver function. Available data indicate that trientine is safe and effective in pediatric WD patients.

In most cases, all side effects of penicillamine** resolve after its discontinuation and do not recur upon taking trientine. The daily dose of the drug is 1–2 g in three divided doses 1 hour before or 3 hours after meals. In adults, trientine is usually prescribed at a dose of 750–1500 mg/day, divided into 2–4 doses.

Trientine chelates iron simultaneously with copper, therefore simultaneous administration of this drug and iron preparations must be avoided, as their complex is toxic. Reversible sideroblastic anemia can be a consequence of excessive therapy. It has been shown that side effects observed during penicillamine** therapy decrease when replacing it with trientine, and do not recur with long-term administration of the drug.

In children over 5 years of age (according to the instructions), the dose is 20 mg/kg/day (can be rounded to the nearest 250 mg) in 2–3 divided doses. The drug is taken 1 hour before or 3 hours after meals, with water. The drug is unstable at high temperatures, so it should be stored in the refrigerator.

Some researchers have suggested that once-daily trientine administration as maintenance therapy may be possible. If confirmed in larger studies, such a dosing regimen will help improve the quality of life for patients. [150].

Efficacy monitoring: same as for penicillamine** therapy.

Side effect monitoring: complete blood count, blood serum iron level test. Frequency: on average, once every 3 months.

Side effects: the most severe side effect is sideroblastic anemia. [151].

3.1.3 Symptomatic therapy for neurological manifestations of WD

In patients with moderate or severe dystonia, S01FA Anticholinergic agents may be used in accordance with the clinical guidelines for "Dystonia" [103, 105]. The choice of drug and treatment method is determined by the clinical situation.

(GoR – C, LoE – 5)

(GoR – C, LoE – 5)

Patients with parkinsonian symptoms are indicated [105] treatment in accordance with the clinical guidelines "Parkinson's disease, secondary parkinsonism and other diseases presenting with parkinsonism syndrome".

• In adult patients with WD and severe chorea, it is recommended to consider prescribing #tetrabenazine** (starting dose 12.5 mg/day, average dose 50–75 mg/day) to alleviate symptoms [103, 105].

Comments: Data on the efficacy of symptomatic treatment of choreoathetosis in WD are very limited.

(GoR – C, LoE – 5)

Comments: Physical therapy services: Exercise therapy for central nervous system and brain disorders, Apparatus- and device-assisted exercise therapy for central nervous system and brain disorders, Motor function impairment correction using biofeedback, Postural-static function recovery training, Dynamic proprioceptive correction.

(CGR – C, LVE – 5

Comments: Treatment of dysarthria in WD is not specific, but is based on general rules of dysarthria treatment, and the approach largely depends on the specific type of speech disorder. In patients with poorly intelligible speech, therapy should be combined with alternative communication methods (e.g., writing, gestures, text-to-speech devices, computer, smartphone, etc.) to improve patients' quality of life.

Speech therapy services: Medical and speech therapy examination for dysphagia, Medical and speech therapy examination for aphasia, Medical and speech therapy examination for dysarthria, Medical and speech therapy procedure for dysphagia, Medical and speech therapy procedure for aphasia, Medical and speech therapy procedure for dysarthria, Medical and speech therapy tonal-rhythmic procedure, Medical and speech therapy procedure using interactive information technologies

(GoR – C, LoE – 5)

Note: Patients should be advised to eat in a calm environment (without watching TV, avoiding talking while eating, and avoiding meals when fatigued, etc.). They should eat and drink slowly, chewing food thoroughly, and not take a new portion of food until the previous one has been swallowed.

Patients with reduced tongue mobility and swallowing disorders may benefit from special body positions, such as lying on their side at a 45° angle during swallowing.

Before initiating dysphagia therapy, treatment with sedative drugs should be discontinued if possible, or doses should be reduced to a single bedtime dose.

Whenever possible, discontinuation should also be considered for R03BB anticholinergics prescribed to reduce salivation when dysphagia develops, as dry mouth may worsen swallowing.

Dry and sticky foods should be avoided.

Starch-based thickeners may be used.

(CGR – C, LVE – 5

Comments: A nasogastric tube may be used temporarily for supplemental nutrition in patients who are able to eat independently.

(CGR – C, LVE – 5

Comments:

It is necessary to verify the presence or absence of copper in the probe material.

(CGR – C, LVE – 5

(CGR – C, LVE – 5

• Epilepsy therapy is recommended to be carried out in accordance with the clinical guidelines "Epilepsy and Status Epilepticus in Adults and Children" for the control and prevention of seizures [34, 90, 103, 104].

(GoR – C, LoE – 5)

Comments: To avoid causing liver dysfunction, the use of antiepileptic drugs with potential hepatotoxic effects (e.g., valproic acid**) should be avoided.

(UCSR – C, UDS – 4)

3.1.4 Therapy during pregnancy and breastfeeding

Pregnancy is not contraindicated in the absence of severe portal hypertension and hepatic failure. It is important to counsel young people regarding fertility and therapeutic management during pregnancy and lactation. Untreated or poorly controlled female WD patients may experience menstrual and ovulatory irregularities due to liver dysfunction and copper-induced toxicity of certain enzymes involved in the normal menstrual cycle and ovulation mechanism. This can reduce their fertility or lead to early pregnancy complications (e.g., spontaneous miscarriage). Initiating chelator therapy to achieve adequate copper control and restore liver function can reverse ovulatory disorders. This also emphasizes the need for copper-chelating therapy prior to pregnancy. Pregnant women with WD should continue taking the medications they were already on to prevent symptom exacerbations. Postpartum, it is recommended to take chelating agents in the same doses as before pregnancy. Regular clinical examination and evaluation of liver function tests, as well as monitoring of blood and urine copper levels, are essential both during and after pregnancy. Since all chelating agents are excreted in breast milk, breastfeeding during lactation is not recommended [164, 165].

(UCSR – C, UDS – 4)

Note: In pregnant women, the maximum daily dose should not exceed 1000 mg/day, and in the 3rd trimester—300–600 mg of penicillamine** [3]. Laboratory parameters of copper metabolism must be monitored in accordance with the Product Information, but at least once every 3 months. If a cesarean section is planned, the daily dose should not exceed 250 mg during the last 6 weeks of pregnancy and in the postoperative period until complete healing.

Therapy must under no circumstances be discontinued upon the onset of pregnancy due to the risk of complications.

Trientine is considered safe during pregnancy, so treatment during pregnancy should be continued [146].

(GoR – C, LoE – 5)

Comment: there is currently insufficient data regarding the effect of #zinc sulfate (zinc preparations) on the breastfed infant. At the same time, there are data on the potential safety of using chelating therapy during breastfeeding [108].

3.2 Surgical Treatment

3.2.1 Liver transplantation

Indications for liver transplantation in patients with WD are the rapid development of severe liver failure with coagulopathy and hepatic encephalopathy, progression of liver dysfunction to liver failure despite medical therapy, or acute/chronic liver failure [31].

(UCSR – C, UDS – 4)

Note: one-year patient survival after emergency transplantation for fulminant liver failure in WD reaches 70%, while without transplantation survival occurs only in isolated cases. When liver transplantation is performed at the stage of decompensated liver cirrhosis, one-year patient survival is 95%, at 5 years—83%, and at 10 years—80%. Improvement of neurological symptoms after transplantation is observed in more than 50% of cases. However, if neurological symptoms persist for more than 2 years despite treatment, improvement in outcomes following orthotopic liver transplantation or continued chelation therapy is unlikely. The survival of patients with the mixed form of WD after liver transplantation is lower compared to the hepatic form. Liver transplantation leads to the normalization of copper metabolism, an increase in ceruloplasmin levels in the first months after surgery, a decrease in urinary copper excretion following transplantation with complete normalization of these parameters by 6–9 months postoperatively, and the disappearance of Kayser–Fleischer rings in the majority of patients [83, 85].

After liver transplantation patients do not require WD therapy [84].

3.2.2 Surgical treatment of neurological complications

• In severe motor (extrapyramidal) disorders resistant to chelating and symptomatic therapy, it is recommended to consider surgical treatment:

- for dystonia — deep brain stimulation (internal segment of the globus pallidus), pallidotomy, thalamotomy;

- for tremor — deep brain stimulation (thalamus), pallidotomy, thalamotomy;

- for parkinsonism — deep brain stimulation or pallidotomy;

for the purpose of correcting these conditions [103, 104].

(GoR – C, LoE – 5)

Comments: in accordance with the clinical guidelines "Dystonia" and "Parkinson's disease, secondary parkinsonism and other diseases presenting with parkinsonism syndrome".

4. Medical Rehabilitation and Sanatorium-Resort Treatment

Medical rehabilitation of patients with WD is aimed at compensating for functional impairments, primarily signs of central nervous system damage. It includes therapeutic exercise for central nervous system and brain diseases, therapeutic exercise using apparatus and exercise equipment for CNS and brain diseases, correction of motor function disorders using biofeedback, postural-static function recovery support, dynamic proprioceptive correction, medical-speech therapy procedure for dysphagia, medical-speech therapy procedure for dysarthria, medical-speech therapy tonal-rhythmic procedure, and medical-speech therapy procedure using interactive information technologies.

There are no large randomized trials evaluating the efficacy of physical therapy (therapeutic exercise). However, isolated reports of its successful application in WD and small case series indicate that physical therapy may be useful in cases of dystonia, for the prevention of contractures, in parkinsonism and ataxia, where gait and balance stabilization methods can be beneficial.

Neuromuscular electrical stimulation has been attempted to improve dysphagia, and percutaneous endoscopic gastrostomy is standard practice to improve nutrition in patients with significantly impaired swallowing [105, 109, 110].

Since the patient's neurological condition is expected to begin improving approximately 6 months after starting pathogenetic therapy, it is important for the patient to maintain a positive attitude during treatment and try to preserve as many physical capabilities as possible.

If the patient experiences extreme communication difficulties, alphabet boards or electronic communication devices may be used [111-114].

5. Prevention and Dispensary Observation

5.1 Prevention

(GoR – C, LoE – 5)

Vaccine prophylaxis

Vaccination should be carried out in accordance with the National Immunization Schedule and general approaches to vaccine prophylaxis. WD is not a contraindication to vaccination [115, 116].

(LoE – C, GoR – 5)

Comment: vaccination is carried out according to the drug's instructions for use.

(LoE – C, GoR – 5)

Comment: for example, against chickenpox, pneumococcal infection [146].

5.2 Dispensary monitoring

(UCSR – C, UDS – 4)

Comments: On average, therapy monitoring is performed 2 times per month during the first year of therapy, and annually thereafter [100, 92]. The lipid profile test is more relevant for adult patients.

Treatment monitoring for children is usually performed more frequently: on average once a week at the initiation phase of therapy (in the first month of treatment) and during the period of increasing the dose of penicillamine**/trientine, after which laboratory and instrumental examinations are carried out every 1–3 months until remission is achieved, and every 3–6 months thereafter (possibly more frequently according to indications) [12].

• For all patients with WD, it is recommended during complex treatment to determine blood creatinine and blood urea levels at least once every 6–12 months during remission, or more frequently according to indications [93, 143, 144].

(Level of reliability of evidence – B, Level of conviction of evidence – 3)

• For all patients with WD, it is recommended during complex treatment to test urine copper levels at least once every 12 months to monitor treatment (possibly more frequently according to indications) [3, 4, 12, 31, 44].

(GoR – C, LoE – 5)

(GoR – C, LoE – 5)

Comments: taking into account equipment upgrades, some device modifications allow determining not only the fibrosis stage but also the degree of liver steatosis, which is also relevant for WD as a metabolic disease.

• For patients with epileptic syndrome, it is recommended to perform routine electroencephalography (EEG) to monitor the treatment of epileptic seizures [102, 61].

(GoR – C, LoE – 5)

Comments: 24-hour EEG with video monitoring may also be performed.

• For patients with neurological symptoms, it is recommended to perform follow-up magnetic resonance imaging (MRI) of the brain according to indications to detect pathological changes in the brain [4, 60, 92, 100, 101].

(CGR – B, LVE – 3)

Comments: general anesthesia is performed if necessary.

(UCSR – C, UDS – 4)

Comments: left ventricular or biventricular hypertrophy, early repolarization, ST-segment depression, T-wave inversion, and various arrhythmias may be detected.

(GoR – C, LoE – 5)

(GoR – C, LoE – 5)

6. Organization of Medical Care

Patients with WD, depending on necessity, may be provided with any type, conditions, and form of medical care stipulated by the legislation of the Russian Federation.

Diagnosis and therapy of WD in children are carried out in specialized inpatient gastroenterology (hepatology) departments involving the following specialists: gastroenterologist, ophthalmologist, neurologist, psychiatrist, nephrologist, hematologist/pediatric hematologist-oncologist, surgeon/pediatric surgeon, medical psychologist, and others based on clinical necessity.

Initial diagnosis and initiation of therapy in children with WD are carried out in a specialized inpatient facility with mandatory assessment of copper metabolism, the degree of hepatic parenchyma fibrosis, and neuropsychological function impairment, along with determining indications for timely orthotopic liver transplantation [3, 4, 31, 83, 85].

Conservative therapy is carried out in a 24-hour or day hospital setting with mandatory monitoring of laboratory parameters and subsequent continuity of care with the outpatient healthcare sector.

Specialized follow-up is carried out 1–2 times a year in a 24-hour hospital setting or a day hospital setting with outpatient monitoring of patients at their place of residence by medical specialists: pediatrician/general practitioner/family physician and gastroenterologist for hepatic and mixed forms of the disease, and neurologist and medical psychologist for the mixed form of WD.

Initial diagnosis, initiation of therapy, and follow-up in adult patients with Wilson's disease are carried out in specialized outpatient or inpatient gastroenterological (hepatological) and/or neurological departments.

7. Additional Information

7.1 Outcomes and prognosis

Wilson's disease is a progressive disorder, and in the absence of timely initiated therapy, patients die from complications of liver cirrhosis and/or, less commonly, progressive neurological symptoms. With effective chelating therapy or successful liver transplantation, the prognosis is favorable.

The prognosis in Wilson's disease is related to the degree of hepatic function decompensation, the severity of neurological symptoms, and therapy adherence. Normalization of liver function occurs within 1–2 years of therapy and does not progress if all recommendations are strictly followed. Conservative therapy is ineffective in fulminant disease courses. A prognostic index for Wilson's disease (Dhawan et al.) was developed, according to which a score above 11 is associated with a high probability of a fatal outcome in the absence of urgent orthotopic liver transplantation (Appendix G2) [47, 86].

Neurological symptoms of Wilson's disease are only partially reversible with chelator therapy and liver transplantation, which is due to irreversible brain damage caused by toxic copper concentrations.

Criteria for Evaluating the Quality of Medical Care

Quality assessment criteria for primary health care provided to adults and children with copper metabolism disorders (Wilson's disease) (ICD-10 codes: E83.0)

Quality assessment criteria for specialized care provided to adults and children with copper metabolism disorders (Wilson's disease) (ICD-10 codes: E83.0)

References

Appendix A1. Working Group Composition

Averkina Natalia Anatolyevna — Candidate of Medical Sciences, Gastroenterologist, Chief Specialist at the Federal State Budgetary Institution "Central Research Institute for Health Information and Informatization" of the Russian Ministry of Health

Anisimova Inga Vadimovna — Candidate of Medical Sciences, Head of the Medical Care Organization Department, Geneticist at the Federal State Budgetary Scientific Institution "Research Centre for Medical Genetics named after Academician N.P. Bochkov", Member of the Association of Medical Geneticists

Bagaeva Madlena Enverovna — Candidate of Medical Sciences, Senior Researcher at the Department of Pediatric Gastroenterology, Hepatology and Dietetics of the Clinic at the Federal State Budgetary Institution of Science "Federal Research Centre of Nutrition and Biotechnology"

Baranov Alexander Alexandrovich — Academician of the Russian Academy of Sciences, Professor, Doctor of Medical Sciences; Honorary President of the Union of Pediatrists of Russia, Advisor to the Head of the Research Institute of Pediatrics and Child Health of the Petrovsky National Research Centre of Surgery, Professor at the Department of Pediatrics and Pediatric Rheumatology of the Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University), Chief freelance pediatric specialist of the Russian Ministry of Health

Batysheva Tatyana Timofeevna — Doctor of Medical Sciences, Professor, Chief freelance pediatric specialist in medical rehabilitation of the Ministry of Health of the Russian Federation, Chief freelance pediatric specialist in neurology of the Moscow Healthcare Department, Director of the Scientific and Practical Center for Pediatric Psychoneurology of the Moscow Healthcare Department, Head of the Department of Neurology, Physical and Rehabilitation Medicine of Childhood at the Institute of Professional Education of RUDN University, Honored Doctor of the Russian Federation

Bykova Olga Vladimirovna — Doctor of Medical Sciences, Head of the Research Department at the Scientific and Practical Center for Pediatric Psychoneurology of the Moscow Healthcare Department, Professor at the Department of Neurology, Physical and Rehabilitation Medicine of Childhood at the Institute of Professional Education of RUDN University

Vashakmadze Nato Dzhemberovna — Doctor of Medical Sciences, Head of the Department of Orphan Diseases and Prevention of Disabling Conditions at the Research Institute of Pediatrics and Child Health of the Petrovsky National Research Centre of Surgery, Professor at the Department of Faculty Pediatrics, Pediatric Faculty, Pirogov Russian National Research Medical University of the Russian Ministry of Health, Member of the Union of Pediatrists of Russia.

Volynets Galina Vasilyevna — Doctor of Medical Sciences, Head of the Gastroenterology Department at the Veltischev Research and Clinical Institute of Pediatrics of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Member of the Association of Pediatric Gastroenterologists, Hepatologists and Nutritionists

Gundobina Olga Stanislavovna — Candidate of Medical Sciences, Leading Researcher, Gastroenterologist at the Research Institute of Pediatrics and Child Health of the Central Clinical Hospital of the Russian Academy of Sciences, Member of the Union of Pediatrists of Russia

Degtyareva Anna Vladimirovna — Doctor of Medical Sciences, Professor, Highest Category Physician, Head of the Pediatrics Department at the National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov

Zhurkova Nataliya Vyacheslavovna — Candidate of Medical Sciences, Leading Researcher at the Research Institute of Pediatrics and Child Health of the Petrovsky National Research Centre of Surgery, Member of the Union of Pediatrists of Russia, Member of the Association of Medical Geneticists

Zakharova Ekaterina Yuryevna — Doctor of Medical Sciences, Head of the Laboratory of Inherited Metabolic Diseases at the Federal State Budgetary Scientific Institution "Research Centre for Medical Genetics named after Academician N.P. Bochkov", Member of the Russian Society of Medical Geneticists, Member of the Society for the Study of Inborn Errors of Metabolism (SSIEM).

Illarioshkin Sergey Nikolaevich — Doctor of Medical Sciences, Professor, Corresponding Member of the Russian Academy of Sciences, Head of the Brain Research Department, Deputy Director for Scientific Work at the Research Center of Neurology

Karaseva Maria Sergeevna — Pediatrician, Researcher at the Research Institute of Pediatrics and Child Health of the Petrovsky National Research Centre of Surgery

Karkashadze Georgy Archilovich — Candidate of Medical Sciences, Neurologist, Head of the Department of Ontogenetic Brain Development, Cognitive Function Formation and Neurobiology at the Research Institute of Pediatrics and Child Health of the Central Clinical Hospital of the Russian Academy of Sciences, Member of the Union of Pediatrists of Russia

Kutsev Sergey Ivanovich — Academician of the Russian Academy of Sciences, Doctor of Medical Sciences, Director of the Federal State Budgetary Scientific Institution "Research Centre for Medical Genetics named after Academician N.P. Bochkov", President of the Association of Medical Geneticists

Alla E. Lavrova — Doctor of Medical Sciences, Director of the Institute of Pediatrics, Head of Pediatric Department No. 2, University Clinic of the Privolzhsky Research Medical University of the Ministry of Health of the Russian Federation, Excellence in Healthcare awardee

Murtazina Aysylu Fanzirovna — Candidate of Medical Sciences, Neurologist, Functional Diagnostics Physician, Senior Researcher at the Scientific Advisory Department of the Federal State Budgetary Scientific Institution "Research Centre for Medical Genetics named after Academician N.P. Bochkov"

Nazarenko Lyudmila Pavlovna — Professor, Doctor of Medical Sciences, Deputy Director for Scientific and Clinical Work, Head of the Laboratory of Hereditary Pathology at the Research Institute of Medical Genetics, Tomsk National Research Medical Center of the Russian Academy of Sciences, Member of the Association of Medical Geneticists

Pashkova Irina Evgenyevna — Candidate of Medical Sciences, Head of the Pediatrics Department at the National Medical Research Center of Transplantology and Artificial Organs Named after Academician V.I. Shumakov

Namazova-Baranova Leyla Seymurovna — Academician of the Russian Academy of Sciences, Professor, Doctor of Medical Sciences, President of the Union of Pediatrists of Russia; Past President of EPA/UNEPSA; Head of the Research Institute of Pediatrics and Child Health of the Petrovsky National Research Centre of Surgery, Head of the Department of Faculty Pediatrics, Pediatric Faculty, Pirogov Russian National Research Medical University of the Russian Ministry of Health, Chief freelance pediatric specialist in preventive medicine of the Russian Ministry of Health

Polyakova Svetlana Igorevna — Doctor of Medical Sciences, Professor at the Department of Hospital Pediatrics Named after Academician V.A. Tabolin, Pediatric Faculty, Pirogov Russian National Research Medical University, Moscow

Potapov Alexander Sergeevich — Doctor of Medical Sciences, Professor, Gastroenterology Department at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Department of Pediatrics and Pediatric Rheumatology of the Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)

Polyakov Alexander Vladimirovich — Professor, Corresponding Member of the Russian Academy of Sciences, Doctor of Biological Sciences, Head of the DNA Diagnostics Laboratory at the Federal State Budgetary Scientific Institution "Research Centre for Medical Genetics named after Academician N.P. Bochkov"

Repina Svetlana Afanasyevna — Candidate of Medical Sciences, Geneticist at the Medical Care Organization Department of the Federal State Budgetary Scientific Institution "Research Centre for Medical Genetics named after Academician N.P. Bochkov", Member of the Association of Medical Geneticists

Rozina Teya Pavlovna — Candidate of Medical Sciences, Associate Professor at the Department of Internal Diseases, Faculty of Fundamental Medicine, Lomonosov Moscow State University, Associate Professor at the Department of Internal, Occupational Diseases and Rheumatology, Sechenov First Moscow State Medical University of the Russian Ministry of Health

Savostyanov Kirill Viktorovich — Doctor of Biological Sciences, Head of the Medical Genetics Center, Head of the Laboratory of Medical Genomics at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Professor at the Department of Pediatrics and Public Health at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Member of the Association of Medical Geneticists

Sviridova Valeria Valeryevna — Geneticist at the Medical Care Organization Department of the Federal State Budgetary Scientific Institution "Research Centre for Medical Genetics named after Academician N.P. Bochkov", Junior Researcher at the Mutagenesis Laboratory of the Federal State Budgetary Scientific Institution "Research Centre for Medical Genetics named after Academician N.P. Bochkov"

Seitova Gulnara Narimanovna — PhD in Medical Sciences, Chief Physician of the Medical Genetics Center (Genetics Clinic), Research Institute of Medical Genetics, Tomsk National Research Medical Center of the RAS

Seliverstov Yury Alexandrovich — Candidate of Medical Sciences, Senior Researcher at the Research Center of Neurology, Member of the Education Committee of the European Section of the International Parkinson and Movement Disorder Society, Member of the Scientific Panel on Movement Disorders of the European Academy of Neurology (EAN)

Selimzyanova Lilia Robertovna — Candidate of Medical Sciences, Head of Department at the Research Institute of Pediatrics and Child Health of the Petrovsky National Research Centre of Surgery, Associate Professor at the Department of Pediatrics and Pediatric Rheumatology of the Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University), Associate Professor at the Department of Faculty Pediatrics of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Member of the Union of Pediatrists of Russia

Skvortsova Tamara Andreevna — Candidate of Medical Sciences, Chief freelance pediatric gastroenterologist of the Moscow Healthcare Department, Head of the Center for Pediatric Gastroenterology and IBD Center, Head of the Gastroenterology Department at the Morozov Children's City Clinical Hospital of the Moscow Healthcare Department

Smirnova Olga Yakovlevna — Geneticist, Senior Researcher at the Department of Standardization and Study of Evidence-Based Medicine Foundations of the Research Institute of Pediatrics and Child Health of the Petrovsky National Research Centre of Surgery

Strokova Tatiana Viktorovna — MD, Professor of the Russian Academy of Sciences, Head of the Department of Pediatric Gastroenterology, Hepatology, and Dietotherapy at the Clinic of the Federal Research Centre of Nutrition and Biotechnology

Subbotin Dmitry Mikhailovich — Medical Geneticist, Research Centre for Medical Genetics named after Academician N.P. Bochkov, Member of the Association of Medical Geneticists

Surkov Andrey Nikolaevich — MD, Head of the Gastroenterology Department for Children at the Children's Hospital, Head of the Department of Scientific Foundations of Pediatric Gastroenterology, Hepatology, and Metabolic Disorders at the Research Institute of Pediatrics and Child Health in Petrovsky National Research Centre of Surgery, Professor at the Department of Faculty Pediatrics, Pediatric Faculty, Pirogov Russian National Research Medical University of the Russian Ministry of Health, member of the Union of Pediatrists of Russia

Sukhanova Natella Vakhtangovna — Head of the Aniridia Center, Researcher at the Research Institute of Pediatrics and Child Health of the Central Clinical Hospital of the Russian Academy of Sciences, ophthalmologist, member of the Association of Pediatric Ophthalmologists of the Russian Federation, member of the Union of Pediatrists of Russia

Tepaev Rustem Faridovich — MD, Head of the Resuscitation and Intensive Care Unit at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Professor at the Department of Pediatrics and Pediatric Rheumatology at Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)

Fedoseenko Marina Vladislavovna — PhD, Head of the Department for the Development of Scientific Approaches to Immunization of Patients with Health Deviations and Chronic Diseases, Leading Researcher, Pediatrician at the Research Institute of Pediatrics and Child Health in Petrovsky National Research Centre of Surgery, Associate Professor at the Department of Faculty Pediatrics at Pirogov Russian National Research Medical University of the Russian Ministry of Health, member of the Union of Pediatrists of Russia

Khavkin Anatoly Ilyich — MD, Chief Researcher at the Gastroenterology Department of the Pirogov Russian National Research Medical University (Veltischev Research and Clinical Institute of Pediatrics), Chairman of the Association of Pediatric Gastroenterologists, Hepatologists, and Nutritionists

The authors declare no financial support/conflict of interest that needs to be disclosed.

Appendix A2. Methodology for Developing Clinical Guidelines

The clinical guidelines are based on current international clinical guidelines for the diagnosis, treatment, and management of patients with Wilson's disease.

Wilson's disease is a rare hereditary disorder, which excludes the possibility of conducting large cohort and randomized controlled trials; therefore, diagnosis and treatment protocols are based solely on expert case studies published over the past two decades.

Target audience for these clinical guidelines:

1. Gastroenterologists

2. Pediatricians

3. Neurologists

4. General practitioners (family physicians)

5. General practitioners

6. Geneticists

7. Ultrasound diagnostics physicians

8. Laboratory physicians

9. Pathologists

10. Medical students

11. Residents and interns

Methods used for evidence collection/selection: electronic database search.

Table 1. Scale for assessing levels of reliable evidence (LRE) for diagnostic methods (diagnostic interventions)

Table 2. Scale for grading levels of evidence certainty (LEC) for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitative interventions)

Table 3. Scale for grading grades of recommendation (GR) for prevention, diagnostic, treatment, and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitative interventions)

Procedure for updating clinical guidelines.

The mechanism for updating the clinical guidelines provides for their systematic revision at least once every three years, as well as upon the emergence of new evidence-based medicine data regarding the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to the previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

Appendix A3.1 Related Documents

Care delivery pathways:

Order of the Ministry of Health and Social Development of the Russian Federation No. 366n dated April 16, 2012 "On approval of the Procedure for providing pediatric care"

Order of the Ministry of Health of the Russian Federation No. 917n dated November 15, 2012, "On Approval of the Procedure for Providing Medical Care to Patients with Congenital and (or) Hereditary Diseases"

Other documents upon which the clinical guidelines are developed

1. Order of the Ministry of Health of the Russian Federation No. 4n dated January 14, 2019, "On Approval of the Procedure for Prescribing Medicinal Products, Prescription Forms for Medicinal Products, the Procedure for Issuing These Forms, Their Accounting and Storage"

2. Order of the Government of the Russian Federation dated December 31, 2018, No. 3053-r, "On approval of the lists of medical devices implantable into the human body during the provision of medical care within the framework of the state guarantee program for free medical care to citizens and dispensed by prescription for medical devices upon the provision of a set of social services"

3. International Statistical Classification of Diseases and Related Health Problems (ICD-10);

4. Order of the Ministry of Health of the Russian Federation No. 1183n dated December 20, 2012 "On approval of the nomenclature of positions of medical and pharmaceutical workers".

5. Order of the Ministry of Health of the Russian Federation No. 541n dated July 23, 2010. "Unified Qualification Handbook of Positions of Managers, Specialists, and Employees, Section: Qualification Characteristics of Positions of Healthcare Workers."

6. Federal Law No. 489-FZ dated December 25, 2018, "On Amendments to Article 40 of the Federal Law 'On Compulsory Medical Insurance in the Russian Federation' and the Federal Law 'On the Fundamentals of Public Health Protection in the Russian Federation' regarding Clinical Guidelines".

7. Order of the Ministry of Health of the Russian Federation No. 103n dated February 28, 2019, "On Approval of the Procedure and Timeframes for the Development and Revision of Clinical Guidelines, Their Template Form, and Requirements for Their Structure, Composition, and Scientific Validity of Information Included in Clinical Guidelines".

8. Order of the Russian Ministry of Health No. 804n dated October 13, 2017, "On approval of the nomenclature of medical services."

9. Order of the Ministry of Labor and Social Protection of the Russian Federation No. 585n dated August 27, 2019, "On Classifications and Criteria Used in Medical and Social Assessment of Citizens by Federal State Institutions of Medical and Social Assessment."

10. Order of the Ministry of Health and Social Development of the Russian Federation dated August 9, 2005, No. 494, "On the procedure for the use of medicinal products in patients for vital indications"

11. Information letter of the Russian Ministry of Health on the possibility of procuring a medicinal product by its trade name (https://www.rosminzdrav.ru/news/2019/12/18/13043-minzdrav-podgotovil-informatsionnoe-pismo-po-vozmozhnosti-zakupki-lekarstvennogo-preparata-po-torgovomu-naimenovaniyu);

Information on medicinal products: https://grls.rosminzdrav.ru/

Main regulatory legal acts governing the provision of palliative medical care

1. Federal Law No. 18-FZ dated March 6, 2019, "On Amendments to the Federal Law 'On the Basics of Protecting the Health of Citizens in the Russian Federation' Regarding the Provision of Palliative Medical Care."

2. Order of the Russian Ministry of Health No. 345n, Russian Ministry of Labor No. 372n dated May 31, 2019, "On approval of the Regulations on the organization of palliative medical care, including the procedure for interaction between medical organizations, social service organizations, and public associations, and other non-profit organizations operating in the field of health protection."

3. Order of the Russian Ministry of Health No. 348n dated May 31, 2019, "On approval of the list of medical devices intended to maintain human organs and body systems, provided for home use."

4. Order of the Russian Ministry of Health No. 505n dated July 10, 2019, "On approval of the Procedure for the transfer by a medical organization to a patient (their legal representative) of medical devices intended to maintain the functions of human organs and body systems for home use in the provision of palliative medical care."

5. Order of the Ministry of Health of the Russian Federation No. 831 dated October 3, 2019, "On Approval of the Departmental Target Program 'Development of the Palliative Medical Care Delivery System'".

Examples of diagnoses:

• Wilson's disease, hepatic form. Cirrhosis of the liver.

• Wilson's disease, mixed form, rigid-arhythmogyperkinetic form. Cirrhosis of the liver.

Appendix A3.2 Clinical signs of WD

Appendix A3.3 Diagnostic criteria for WD (causes of false-negative and false-positive results)

Appendix A3.4 Dietary recommendations for WD

Appendix A3.4 Decoding of notes

…^** – the drug is included in the list of vital and essential drugs (Order of the Government of the Russian Federation No. 2406-r dated October 12, 2019

# - The use of the medicinal product in accordance with indications (characteristics) not specified in the instructions for its use (off-label) is carried out by decision of the medical commission, subject to a signed informed voluntary consent (in accordance with Federal Law No. 323-FZ dated November 21, 2011, as amended);

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

What is Wilson's disease?

Wilson's disease (hepatolenticular degeneration, Wilson-Konovalov disease) is a severe hereditary disease of the central nervous system and internal organs associated with impaired copper metabolism.

Wilson's disease is caused by mutations in the ATP7B gene, which is responsible for the synthesis of the copper-transporting protein (ATP7B). When its function is impaired, the metabolism of copper and copper-containing proteins is disrupted, and an excess of "free" copper appears, which is deposited in large quantities in the liver, brain, and cornea, and is also excreted in the urine. Diagnosis of the disease is based on the detection of characteristic disorders of copper metabolism. Damage to the liver by an excess of "free" copper manifests as liver cirrhosis. Damage to the brain leads to the development of severe neurological symptoms: tremor of the extremities and the entire body, increased muscle tone, sometimes accompanied by painful spasms, speech and swallowing disorders, and intellectual decline. The deposition of copper in the cornea (along the edge of the iris) causes the formation of the brownish-green Kayser-Fleischer ring.

Wilson's disease is a rare example of a hereditary disorder for which highly effective treatments have been developed: even with the onset of severe neurological symptoms, systematic treatment is highly effective, up to the complete disappearance of all symptoms or their sharp reduction. Patients can once again fully care for themselves, do housework, study, work in their profession, start a family, and have a healthy child.

How does Wilson's disease manifest?

The first symptoms usually appear at the age of 5–40 years, rarely (≈3%) at a later age. The main target organs in Wilson's disease are the nervous system and the liver. The clinical picture of the disease is very diverse, and clinical manifestations may differ in different patients. If left untreated, the disease progresses, and liver failure and irreversible changes in the nervous system may occur. Early diagnosis and treatment alleviate symptoms and prevent complications.

1. Liver changes: observed in approximately 50% of patients; more often in children and adolescents — hepatomegaly, hepatic steatosis, acute or chronic hepatitis (resembling acute viral or autoimmune hepatitis), liver cirrhosis with signs of portal hypertension, and acute liver failure.

2. Neurological disorders: in 40–50% of patients, tremor, parkinsonism (bradykinesia and muscle rigidity), ataxia (coordination disorders, unsteadiness when walking), dystonia (from focal to generalized), dysarthria (slurred speech), and swallowing disorders may develop.

3. Mental changes: observed in 10% of patients; personality disorders (mood swings, problems at school or work, impulsive behavior), affective disorders, and psychoses.

4. Changes in other organs and systems: eye changes (Kayser-Fleischer ring [copper deposits – visible on slit-lamp examination as golden-brown pigmentation of the corneal limbus], cataracts), hemolytic anemia (in approximately 15% of patients), kidney damage, cardiomyopathy, arrhythmia, osteomalacia, osteoporosis, arthritis, pancreatitis (inflammation of the pancreas), delayed puberty, infertility, amenorrhea, hypothyroidism, or hypoparathyroidism.

Early-stage disease can be suspected based on the following signs: liver damage (jaundice, recurrent nosebleeds, bleeding gums or multiple bruises, spider angiomas on the skin of the chest and back), and nervous system damage (movement disorders, intellectual decline, and mental changes in the form of mood swings, difficulty absorbing new material, and school performance problems).

How is Wilson's disease inherited?

Wilson's disease is inherited in an autosomal recessive manner. This means that the disease manifests only if both parents are carriers of the disease and, although they are not ill themselves, pass on two affected genes to the child. Most families with a child having this condition have not previously encountered such a problem. The risk of having another sick child in a family that already has sick children is 25% for each pregnancy. Pathogenic variants in the ATP7B gene are the cause of this disease.

Brothers and sisters of a sick child may be ill, even if they had no symptoms at the time of family screening. In this case, diagnostics must be performed to start therapy as early as possible and avoid complications. They can also be carriers, like their parents. As for other family members, it is important to inform them that they may be carriers. This means that they also have a risk of having a child with this condition. The earlier treatment is started (ideally at the presymptomatic stage or at the pre-neurological stage, i.e., before the signs of brain damage appear), the better the effect.

All families with Wilson's disease must undergo medical genetic counseling and receive complete information from a geneticist about the risk of recurrence of this disease in the family, and discuss all issues related to the inheritance of the disease with a specialist. In Russia, medical genetic consultations operate in every region.

For prenatal and preimplantation diagnosis, a couple must first undergo screening for carrier status of mutations in the ATP7B gene by contacting specialized diagnostic laboratories and medical centers. Prenatal diagnosis is carried out using molecular genetic methods by examining DNA isolated from chorionic villus sampling and/or amniotic fluid cells and/or fetal blood.

How is Wilson's disease diagnosed?

Based on clinical signs, a doctor may suspect the disease, after which a number of laboratory and instrumental research methods are performed to confirm the diagnosis.

1. Blood test: increased serum aminotransferase activity (in almost all patients, initially asymptomatic), decreased serum ceruloplasmin concentration (in the majority of patients <20 mg/dL), and decreased total serum copper concentration (usually <1 mg/L).

2. Urine test: in approximately 80% of patients, 24-hour urinary copper excretion is >100 µg (>1.6 µmol).

3. Imaging studies: ultrasound, CT, and MRI — depending on the stage of the disease — hepatomegaly or signs of portal hypertension (splenomegaly); brain MRI and CT show changes in the basal ganglia and brainstem in patients with neurological symptoms.

4. Genetic testing: analysis of the ATP7B gene. As a rule, initial tests are performed for the most frequent pathogenic variants, and then — if necessary — the entire gene is analyzed using sequencing methods.

How are patients with Wilson's disease treated?

First, this is strict adherence to a "liver" diet (Diet No. 5a), which involves excluding copper-rich foods (chocolate, coffee, nuts, legumes, shellfish, etc.). Alcohol consumption must be avoided.

However, the main treatment is the continuous intake of medications that remove copper from the body. The main one is penicillamine**. Therapy must not be stopped without valid reasons, including during pregnancy.

These drugs are prescribed according to a special regimen with a gradual increase in dose. With long-term, multi-year use of penicillamine, some patients experience side effects such as dermatitis, anemia, and other complications. Therefore, an alternative method of treatment with zinc preparations was proposed. Combined treatment with penicillamine** and zinc preparations makes it possible to reduce the dose and avoid side effects. In patients at the presymptomatic stage, treatment with zinc preparations alone is sufficient.

In severe cases of the disease refractory to conservative treatment, liver transplantation is used. Liver transplantation is indicated for acute liver failure. With a successful surgical outcome, the patient does not require further medication.

Thus, with proper therapy for hepatolenticular degeneration—a severe hereditary disease of the brain and internal organs—clinical recovery or marked improvement is possible in 80% of cases, provided that diagnosis is made in a timely and maximally early manner.

What monitoring should be performed?

After initiating treatment, initially every 1–2 months, then 1–2 times a year, regular follow-up examinations are required: neurological examination, complete blood count with differential, liver and kidney function tests, serum copper concentration, and 24-hour urinary copper excretion.

How do patients receive treatment in the Russian Federation?

Wilson's disease is among the rare hereditary metabolic disorders and is included in the list of rare (orphan) diseases funded by the regional budget. Once diagnosed, the patient must be included in the regional segment of the registry for life-threatening rare (orphan) diseases to ensure future provision of necessary medical nutrition and medicinal products. Different specialists are responsible for maintaining the registry in different regions, but most often these are medical geneticists; therefore, after establishing a diagnosis, it is essential to consult a regional medical geneticist.

How can family and loved ones help?

Do not forget—treatment success also depends on the family. Recommendations must be followed, therapy "lapses" must be avoided under any circumstances, and attention should be paid to rehabilitation and scheduled examinations. All family members must know that the patient requires special nutrition and regular medication.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Appendix G1 Wilson's Disease Diagnostic Rating Scale

Leipzig, 2001 [3, 26]

Russian title: Wilson's Disease Diagnostic Scoring System, Leipzig, 2001

Original title: Scoring system developed at the 8th International Meeting on Wilson’s disease, Leipzig 2001

Source: [26]

Type: rating scale

Purpose: establishing the diagnosis of Wilson's disease

Content:

Key (interpretation):

Total score:

4 or more: diagnosis of Wilson's disease established;

3: diagnosis of Wilson's disease probable, but further patient evaluation required;

2 or less: diagnosis of Wilson's disease unlikely.

Appendix G2 Wilson's Disease Prognostic Index

(modified by Dhawan et al.) [47, 86]

Russian title: New Wilson Index

Original title: New Wilson Index for Predicting Mortality

Source: [47, 86]

Type: rating scale

Purpose: assessing the probability of mortality without liver transplantation in Wilson's disease.

Content:

Key (interpretation):

A total score of ≥11 is associated with a high probability of mortality without liver transplantation.