Other disorders of lipid storage (Lysosomal acid lipase deficiency): clinical guidelines

List of Abbreviations

ALT – alanine aminotransferase

AST – aspartate aminotransferase

ApoB – apolipoprotein B

CESD – cholesterol ester storage disease

HMG-CoA – hydroxymethylglutaryl-coenzyme A

LAL-D – lysosomal acid lipase deficiency

IMT – intima-media thickness

LAL – lysosomal acid lipase

LDL – low-density lipoproteins

HDL – high-density lipoproteins

VLDL – very low-density lipoproteins

MRI – magnetic resonance imaging

NAFLD – non-alcoholic fatty liver disease

NASH – non-alcoholic steatohepatitis

CVA – cerebrovascular accident

LPO – lipid peroxidation

SREBP – sterol regulatory element-binding protein

TG – triglycerides

HSCT – hematopoietic stem cell transplantation

UDCA – ursodeoxycholic acid

USDG – ultrasound Dopplerography

US – ultrasound examination

ERT – enzyme replacement therapy

EGD – esophagogastroduodenoscopy

ECG – electrocardiogram

CE – cholesterol esters

EchoCG – echocardiography

Terms and Definitions

Lysosomal storage diseases — a group of hereditary monogenic disorders associated with impaired lysosomal function.

Enzyme replacement therapy — treatment consisting of the administration of enzymes (including recombinant ones) to patients with an inherited metabolic defect.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Lysosomal acid lipase deficiency (LAL-D) is a progressive hereditary disease caused by a defect in the LIPA gene encoding the enzyme lysosomal acid lipase (LAL), which leads to the accumulation of cholesterol esters and triglycerides in organs and tissues [1-3].

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

LAL-D is inherited in an autosomal recessive manner. The disease is associated with mutations in the LIPA gene, which is mapped to chromosome 10 (10q23.31). The Human Gene Mutation Database describes about 100 mutations in the LIPA gene leading to impaired enzyme function. In LAL-D, nonsense mutations, major gene rearrangements, and frameshift mutations in a homozygous or compound heterozygous state are typically detected in severe forms of the disease [1,3,4]. The most common pathogenic allele is a synonymous change disrupting a splice site in exon 8 c.894G>A (E8SJM-1G>A), which accounts for the disease in more than half of published cases. The presence of this variant in a homozygous or compound heterozygous state retains 3–5% of residual LAL activity [1–3].

Normally, neutral fats (cholesterol esters and, to a lesser extent, triglycerides) entering the lysosome via receptor-mediated endocytosis are cleaved by LAL into free cholesterol and fatty acids. These lipids and their oxidized derivatives interact with transcription factors (sterol regulatory element-binding proteins — SREBPs), which directly modulate the expression of genes involved in cholesterol synthesis and uptake, as well as lipogenesis. In the absence or reduction of LAL activity, cholesterol esters and triglycerides are not degraded and accumulate in lysosomes. The resulting cellular shortage of free cholesterol leads to SREBP-mediated stimulation of endogenous cholesterol synthesis, inhibition of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase, and endocytosis via LDL receptors. Concurrently, apolipoprotein B (ApoB) synthesis increases, and very low-density lipoprotein (VLDL) cholesterol production rises significantly. Increased expression of HMG-CoA reductase is a primary result of SREBP-2-mediated intracellular cholesterol depletion, leading to an increase in free cholesterol levels [1, 2].

Thus, the accumulation of cholesterol esters and triglycerides in organs and tissues is accompanied by dyslipidemia: blood serum shows elevated levels of cholesterol and LDL, while HDL levels are normal or reduced. Hypertriglyceridemia is recorded in some patients.

In the most severe infantile form of LAL-D — Wolman disease — enzyme activity is less than 1% of normal, leading to rapid massive accumulation of cholesterol esters and triglycerides in the lysosomes of many organs and tissues, primarily the liver, spleen, adrenals, intestinal villi, bone marrow, lymph nodes, and macrophages of the reticuloendothelial system, which causes the polysystemic manifestations of the disease.

In cholesterol ester storage disease (CESD), a phenotype of LAL-D characterized by slower progression and variable clinical manifestations, residual LAL activity in vitro ranges from 1–12% of normal [1-4].

1.3 Epidemiology of the Disease or Condition

The prevalence of LALD varies depending on ethnic and geographical factors. The incidence of LALD is estimated to be approximately 1:40,000 to 1:300,000 live births [3]. The incidence of the infantile form of the disease is 2–2.5 times lower, at 1 in 100,000 to 500,000 live births [5-7]. Studies investigating the incidence of LALD in Russia were conducted in Moscow. This figure was approximately 1:70,000 newborns [8].

1.4 Features of Coding the Disease or Condition

According to ICD-10, the disease belongs to Class IV, Endocrine, nutritional and metabolic diseases, E75.5 Other lipid storage disorders.

1.5 Classification of the disease or condition

There are two main forms of LALD (Appendix A3):

- infantile (Wolman disease) — manifesting in the first 6 months of life

- cholesteryl ester storage disease (CESD), with onset at an age older than 6 months (most commonly at 2–5 years) [3, 46].

It should be noted that LALD is a spectrum of clinical phenotypes with varying disease courses and prognoses [3].

1.6 Clinical presentation of the disease or condition

LALD presents with various phenotypes ranging from a rapidly progressive lethal infantile form and severe childhood variants with serious complications, such as cirrhosis and liver failure in adolescence, to subclinical, mild forms manifesting at an older age [3].

1.6.1 Clinical presentation in the infantile form of LAL-D (Wolman disease)

The infantile form of LALD (Wolman disease, WD) is a rare, rapidly progressive disorder manifesting in the first months of life and leading to liver failure and death by the age of 1 year [9].

The most characteristic features of WD are gastrointestinal manifestations, including vomiting, diarrhea, and/or steatorrhea. Abdominal distension due to intestinal bloating, hepatomegaly, and/or hepatosplenomegaly, as well as weight loss with the development of malnutrition and, in severe cases, cachexia, are frequently detected. Growth and physical development retardation are also characteristic. In addition, these patients typically exhibit intermittent fever, lethargy, asthenia, and hyperreflexia [2, 9, 10]. Patients develop anemia and thrombocytopenia.

A hallmark of WD is enlargement and calcification of the adrenal glands, occurring in approximately 50% of cases [2]. According to imaging studies, the enlarged adrenal glands retain their semilunar or pyramidal shape, and punctate calcification foci are identified throughout their parenchyma [11]. The absence of adrenal calcifications does not exclude the diagnosis.

Patients with WD are characterized by neurological symptoms caused by hepatic encephalopathy.

WD involves a malabsorption syndrome associated with fatty acid deficiency and intestinal mucosal damage, manifesting as varying degrees of diarrhea, steatorrhea, small intestinal bacterial overgrowth syndrome, and flatulence [3, 9].

Macroscopically, the liver is significantly enlarged, yellow, with a fatty cut surface. Hepatocytes and Kupffer cells in all zones of the lobule contain lipid vacuoles, which microscopically corresponds to microvesicular fatty degeneration. In frozen sections stained with Sudan Black B, lipid vacuoles are detected, which appear as reddish crystals under polarized light. Portal and periportal fibrosis often progresses to micronodular liver cirrhosis.

Ultrastructural examination of lysosomes reveals the accumulation of substrates with globular and crystalline appearances.

Currently, an immunohistochemical antibody panel has been developed for accurate morphological diagnosis. The detection of cathepsin D and the expression of membrane lysosomal markers, such as lysosome-associated membrane proteins 1 and 2 (LAMP 1 and 2) and lysosomal integral membrane protein 2 (LIMP 2) around lipid vacuoles, confirms intralysosomal lipid accumulation. In addition, histological features also include the accumulation of ceroid in macrophages [3, 10].

Cases of WD with intrauterine manifestation in the form of adrenal necrosis, polyhydramnios, accumulation of cholesteryl esters (CE) in organs and tissues, and microvesicular hepatic steatosis have been described [12]. WD can be a cause of intrauterine fetal death. Autopsy at 17 weeks of gestation demonstrated lipid accumulation in hepatocytes and syncytiotrophoblasts, as well as necrosis in the fetal adrenal gland [9].

Patients with WD present with hepatomegaly or hepatosplenomegaly, and rapidly develop liver failure culminating in liver cirrhosis. Blood biochemistry reveals a marked increase in transaminase levels, a significant rise in bilirubin, and cholestasis syndrome. Frequently encountered laboratory findings in WD include elevated levels of lactate dehydrogenase and serum ferritin, along with decreased hemoglobin and signs of hypocoagulation.

1.6.2 Clinical presentation in cholesterol ester storage disease (CESD)

The disease debuts at an age older than 6 months. CESD is characterized by a slower progression and, as a rule, the absence of neurological symptoms. LALD is a multisystem disease, and symptoms may be caused by damage to various organs. The main target organs are the liver, spleen, gastrointestinal tract, kidneys, and blood vessels. The median age for the onset of the first clinical symptoms of the disease is 5 years, but manifestation in adulthood is also possible [13].

The disease manifests with hepatomegaly (predominantly affecting the right lobe of the liver) due to the accumulation of CE in hepatocytes and Kupffer cells, which is detected in 99% of patients [2], cytolysis syndrome, and dyslipidemia. As the disease progresses, liver fibrosis and cirrhosis develop with the onset of liver failure.

Splenomegaly is caused by the deposition of CE in macrophages and the progression of liver cirrhosis with the development of portal hypertension, which is accompanied by worsening signs of hypersplenism (anemia, leukopenia, thrombocytopenia). Splenomegaly is detected in 74% of patients [2, 13].

Dyslipidemia manifests as elevated serum levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides, with normal or low high-density lipoprotein cholesterol levels (type IIb hyperlipoproteinemia), which can lead to the accelerated development of atherosclerosis [1-4]. Hypercholesterolemia is detected in 81% of patients with CESD, and elevated LDL cholesterol concentrations are found in all patients. Even with lipid-lowering therapy, hypercholesterolemia persists in a quarter of patients, and high LDL levels in half of them. Analysis of the apolipoprotein profile in the majority of patients reveals an elevated level of the main LDL apolipoprotein — apoB [2].

Cytolysis syndrome — an increase in AST and ALT levels — is observed in almost all patients and often serves as one of the first manifestations of the disease. The activity of these enzymes in the blood varies over a wide range (from 2–5 times the upper limit of normal to 10–20 times these values) [2].

Due to intestinal involvement in the pathological process, some patients may experience malabsorption syndrome (malnutrition, diarrhea, steatorrhea, impaired absorption of fat-soluble nutrients).

Disease progression leads to liver fibrosis and cirrhosis, manifested by hepatosplenomegaly, jaundice, ascites, and esophageal varices [2, 10]. There are reports of 2 cases of hepatocellular carcinoma developing against the background of CESD [14].

Adrenal calcification is described in only 5% of patients with CESD [2, 13]. Due to the early development of atherosclerosis, coronary artery disease (CAD), aortic aneurysm, and stroke at a young age are frequently observed.

If a patient presents with signs of hepatic steatosis, a negative alcohol history, and an absence of stigmata of chronic alcohol intoxication (enlargement of the parotid glands, Dupuytren's contracture, etc.), differential diagnosis between NAFLD and LALD (CESD) is necessary. The combination of cytolysis syndrome, hepatic steatosis, type IIb dyslipidemia, and splenomegaly in children and young individuals with normal body weight may indicate the presence of CESD.

Thus, CESD should be suspected in young patients with hepatomegaly, elevated serum ALT and AST, who may also exhibit elevated total cholesterol and low-density lipoprotein cholesterol levels together with a slight or moderate decrease in high-density lipoprotein cholesterol and hypertriglyceridemia (Appendix A3) [2, 13].

1.6.3 Diseases with a clinical presentation similar to LAL-D

Differential diagnosis of LALD is carried out with other lysosomal storage diseases — Niemann-Pick disease types A, B, and C, Gaucher disease, gangliosidoses, as well as disorders of glycogen, fatty acid, and bile acid metabolism, Wilson's disease, familial hypercholesterolemia, and non-alcoholic fatty liver disease [1, 13]. Patients with LALD may be monitored for a long time under diagnoses such as cryptogenic liver cirrhosis or hepatitis of unclear etiology [1, 2, 13].

2. Diagnostics, medical indications and contraindications for diagnostic methods

Please note that in accordance with the requirements for the development of clinical guidelines, each recommendation statement must indicate the strength of recommendations and the evidence base in accordance with the grading scales for the levels of evidentiary certainty (LEC) and the levels of recommendation persuasiveness (LRP). For many statements, the LRP and LEC will be low due to the lack of high-design clinical trials dedicated to them. Despite this, they are necessary elements of patient examination to establish a diagnosis and choose treatment tactics.

Criteria for establishing diagnosis and conditions.

Determination of LAL activity in dried blood spots is the "gold standard" for diagnosing this disease. Detecting reduced LAL activity confirms the diagnosis.

The diagnosis of CESD is established based on a combination of anamnestic and clinical data, as well as the results of laboratory, instrumental, and morphological diagnostic methods.

2.1 Complaints and Anamnesis

When taking the medical history and collecting complaints, attention should be paid to the following complaints and anamnestical events:

- a burdened family history (similar symptoms in the proband's siblings, consanguineous marriage);

- cases of sudden infant death in the family;

- physical developmental delay;

- weakness, increased fatigue;

- hepatomegaly or hepatosplenomegaly;

- diarrhea, abdominal pain, steatorrhea (in case of intestinal involvement);

- epistaxis;

- yellowish skin discoloration;

- ascites;

- esophageal varices (if liver cirrhosis develops).

Complaints and medical history are also described in the "Clinical Presentation" section.

2.2 Physical Examination

2.2.1 Physical examination in the infantile form of LAL-D (Wolman disease)

Upon physical examination, attention should be paid to the following main clinical manifestations:

- enlarged liver;

- enlarged spleen;

- abdominal enlargement;

- malabsorption syndrome;

- hypotrophy, up to severe physical developmental delay;

- progressive psychomotor developmental delay, hyperreflexia;

- yellowish skin discoloration;

- signs of liver failure.

2.2.2 Physical examination for cholesteryl ester storage disease (CESD) with onset over 6 months of age

Upon physical examination, attention should be paid to the following clinical manifestations:

- enlarged liver;

- enlarged spleen.

Detailed physical examination findings are described in the "Clinical Presentation" section.

2.3 Laboratory Diagnostics

2.3.1 Laboratory diagnostic tests in the infantile form of LAL-D (Wolman disease)

Comment: Determining LAL activity in dried blood spots confirms or rules out the diagnosis of CESD and is the gold standard for diagnosing this disease. Guidelines for collecting blood onto filter paper cards are provided in Appendix A3.

Comments: Most patients with CESD are homozygous or compound heterozygous for mutations in the coding region of the LIPA gene. However, intronic mutations and large gene rearrangements have been described that are not detected by standard genetic testing. The pathogenicity of newly identified rare mutations requires additional evidence. Since genotype-phenotype correlation is currently established only at the level of the clinical form of CESD (Wolman disease vs. CESD), but does not hold for individual phenotypic features, molecular genetic testing is used to confirm rather than establish the diagnosis of CESD. Identifying a familial LIPA gene mutation makes it possible to screen the proband's relatives and perform prenatal and preimplantation genetic diagnosis.

Comments: As part of the complete blood count (CBC) with differential, it is necessary to: determine the levels of total hemoglobin, erythrocytes, leukocytes, and platelets in the blood, perform a differential leukocyte count (leukocyte formula), examine a blood smear to analyze abnormalities in erythrocyte, platelet, and leukocyte morphology, determine the color index, and assess erythrocyte size,

determine the erythrocyte sedimentation rate. The pathogenetic mechanisms underlying anemia and thrombocytopenia are not fully understood. One possible mechanism is the accumulation of cholesterol esters and triglycerides in cells of the mononuclear phagocyte system. In addition, anemia may be of nutritional deficiency origin or result from hypersplenism associated with portal hypertension. Thrombocytopenia is also a consequence of hypersplenism. Cases of secondary hemophagocytic lymphohistiocytosis have been described.

Given the extreme rarity of Wolman disease, early onset, late diagnosis, and typically severe course, there are no reliable data on the required frequency of this test. The frequency of the complete blood count (CBC) is dictated by the patient's clinical condition.

Comments: patients with Wolman disease are characterized by a significant increase in transaminase activity (ALT, AST), hypercholesterolemia, hyperbilirubinemia, and possible hypertriglyceridemia; elevated LDL concentrations, and reduced HDL levels in many patients. Apolipoprotein profiling reveals an elevation in apolipoprotein B, the major LDL apolipoprotein, in the majority of patients.

Given the extreme rarity of Wolman disease, early onset, late diagnosis, and severe disease course, reliable data on the required frequency of testing are lacking. The frequency of the general biochemical blood test is dictated by the patient's clinical condition. During diagnosis, alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase activities are determined in the blood, along with total bilirubin, conjugated bilirubin, cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. Dynamically, the activities of alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase, as well as the levels of total bilirubin, conjugated bilirubin, cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides in the blood are monitored (at least once a month).

Comment: if necessary, thrombin time and blood fibrinogen levels are also determined. These indicators allow monitoring of synthetic liver function, detection of hepatocellular insufficiency syndrome, and timely prevention of complications associated with hemostatic disorders [49].

Comments: if signs of adrenal insufficiency are detected, it is indicated to test blood levels of total cortisol, adrenocorticotropic hormone, and glucose, determine plasma renin activity, and measure blood sodium and potassium levels.

2.3.2 Laboratory diagnostic tests for cholesteryl ester storage disease (CESD)

Comment: Determining LAL activity in dried blood spots confirms or rules out the diagnosis of CESD and is the gold standard for diagnosing this disease. Guidelines for collecting blood onto filter paper cards are provided in Appendix A3.

Comments: Most patients with LAL-D are homozygous or compound heterozygous for mutations in the coding region of the LIPA gene; intronic mutations and extensive gene rearrangements not detectable by standard genetic testing have also been described. Furthermore, the pathogenicity of identified rare and novel mutations requires additional evidence. Since gene-phenotype correlation is currently established only at the level of the clinical form of LAL-D (WT or CESD), but is not observed for individual phenotypic traits, molecular genetic testing is used to confirm rather than establish the diagnosis of LAL-D. Identification of a familial LIPA gene mutation makes it possible to screen relatives of the proband, as well as to perform prenatal and preimplantation genetic testing.

Comments:As part of the complete blood count with differential, it is necessary to assess: total hemoglobin level,erythrocytes,leukocytes,blood platelets, differential leukocyte count (leukocyte formula), blood smear review to analyze morphological abnormalities of erythrocytes, platelets, and leukocytes, color index determination, erythrocyte size determination,

erythrocyte sedimentation rate (ESR) testing. The pathogenetic mechanisms underlying the development of anemia and thrombocytopenia are not fully understood. One possible mechanism is the accumulation of cholesterol esters and triglycerides in cells of the macrophage-monocyte system. In addition, anemia may be nutritional/deficiency-related or result from hypersplenism. Thrombocytopenia is a consequence of hypersplenism associated with portal hypertension; alongside this, cases of secondary hemophagocytic lymphohistiocytosis have been described.

Comments: most patients with CESD exhibit elevated transaminase activity (ALT, AST), hypercholesterolemia, hypertriglyceridemia, and increased LDL concentration, while many patients have decreased blood HDL levels. Apolipoprotein profiling reveals an elevated level of apolipoprotein B, the main apolipoprotein of LDL.

Comments: if necessary, thrombin time and blood fibrinogen levels are also determined. These parameters make it possible to monitor the synthetic function of the liver, detect hepatocellular insufficiency syndrome, and promptly prevent complications associated with hemostatic disorders [49].

2.4 Instrumental Diagnostics

2.4.1 Instrumental diagnostic procedures for the infantile form of LAL-D (Wolman disease)

Comments: Abdominal ultrasound makes it possible to determine the size of the liver and spleen, determine the diameter of the portal and splenic veins, the presence of hepatic steatosis, fibrosis, or cirrhosis, and adrenal calcifications.

The frequency of comprehensive abdominal and retroperitoneal ultrasound (including adrenal ultrasound) is dictated by the patient's condition, but should be at least once a month

Comments: performing EGD in patients with hepatic fibrosis and signs of portal hypertension is necessary to assess the grade of esophageal varices and bleeding risk

Comments: may be performed to assess liver tissue status, determine the presence and severity of steatosis, and stage fibrosis.

Macroscopically, the liver has a bright yellow-orange color; the histological picture is characterized by microvesicular steatosis, foamy Kupffer cells, and signs of hepatic fibrosis and cirrhosis [13, 19].

The use of non-invasive techniques is preferred, such as liver elastography (elastometry) and magnetic resonance imaging (MRI) of the abdominal cavity [39].

2.4.2 Instrumental diagnostic procedures for cholesterol ester storage disease (CESD) with onset after 6 months of age

Comments: Liver and spleen ultrasound can detect hepatomegaly and, less frequently, splenomegaly, as well as hepatic steatosis, fibrosis, or cirrhosis. Retroperitoneal ultrasound, including adrenal ultrasound, may reveal adrenal calcifications (extremely rare in patients with CESD, no more than 5%).

Comments: assessing the severity of fatty liver disease (by MRI) is necessary for subsequent monitoring of enzyme replacement therapy efficacy. Average frequency of examinations: abdominal MRI – once a year, liver elastography – once every 6 months.

Comments: performing EGD in patients with hepatic fibrosis and signs of portal hypertension is necessary to assess the grade of esophageal varices and bleeding risk

Comment:

In the presence of arrhythmia, 24-hour Holter ECG monitoring is required, with a stress test (exercise ECG) indicated in accordance with guidelines for the management of patients with atherosclerosis and arrhythmia.

Comment: according to Order No. 804n of the Russian Ministry of Health dated October 13, 2017, "On Approval of the Nomenclature of Medical Services": Duplex scanning of brachiocephalic arteries with color Doppler blood flow mapping, Duplex scanning of extracranial segments of brachiocephalic arteries, Duplex scanning of brachiocephalic arteries and radial arteries with rotational tests.

Additionally, measurement of the ankle-brachial index and assessment of coronary artery calcification may be performed [38].

Comments: may be performed to assess liver tissue status, determine the presence and severity of steatosis, and stage fibrosis.

Macroscopically, the liver has a yellow-orange color; the histological picture is characterized by microvesicular steatosis, foamy Kupffer cells, and signs of liver fibrosis and cirrhosis [13, 19].

Non-invasive methods are preferred, such as ultrasound, liver elastography (liver elastometry), and magnetic resonance imaging of the abdominal organs [39].

2.5 Other Procedures

2.5.1 Other diagnostic tests in the infantile form of LAL-D (Wolman disease)

Comment: patients with Wolman disease are monitored by a gastroenterologist and/or pediatrician during diagnosis and at least once a month thereafter, as well as by a geneticist. A dietitian consultation is required to prescribe a low-fat diet, correct malabsorption (cessation of breastfeeding, selection of a specialized diet restricting animal fats, use of infant formula with medium-chain triglyceride formula, and in some situations, parenteral nutrition) [2, 15], a pediatric cardiologist consultation to assess cardiovascular disorders and therapy [2, 13, 15, 20, 26], a neurologist consultation to assess nervous system disorders [14], and a transplantologist consultation if there are indications for liver transplantation. In life-threatening conditions, the involvement of an anesthesiologist-intensivist is necessary. Initial and follow-up consultations with other specialists, as well as a medical psychologist, are indicated for patients with Wolman disease who have dysfunctions of other organs and systems.

2.5.2 Other diagnostic tests in cholesterol ester storage disease (CESD)

Comment: patients with LAL-D are monitored by a gastroenterologist, general practitioner (or pediatrician in pediatric practice), and geneticist; a dietitian consultation is required to prescribe a low-fat diet (selection of a specialized diet restricting animal fats) [2, 15], a cardiologist (pediatric cardiologist) consultation to assess cardiovascular disorders and therapy (assessment of vascular risk, prescribing treatment, initially and subsequently every 6 months) [2, 13, 15, 20, 26], a transplantologist consultation if there are indications for liver transplantation, and a neurologist consultation if indicated. In life-threatening conditions, the involvement of an anesthesiologist-intensivist is necessary.

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

The treatment of LAL deficiency includes both pathogenetic therapy—enzyme replacement therapy (ERT)—and symptomatic therapy. Management of patients with LAL deficiency involves a multidisciplinary approach with the mandatory participation of gastroenterologists, pediatricians/general practitioners, geneticists, dietitians, cardiologists, and other specialists with experience in treating this rare disease.

3.1 Pathogenetic treatment

3.1.1 Pathogenetic treatment in the infantile form of LAL-D (Wolman disease)

Comments: The ERT medicinal product is sebelipase alfa**. 1 ml of solution contains 2 mg of sebelipase alfa**. It is a recombinant form of human lysosomal acid lipase produced using recombinant DNA technology in a chicken egg cell culture. ERT is intended to restore sufficient enzymatic activity to hydrolyze accumulated cholesterol esters and prevent their further accumulation. Following administration, sebelipase alfa** is rapidly cleared from the systemic circulation and taken up by cells, entering their lysosomes via mannose-6-phosphate receptors.

Administration of the drug is parenteral in the form of intravenous infusions. Administration is carried out through a peripheral venous catheter (peripheral catheter) or through a port system (implantable infusion/injection port***), which are installed in accordance with the guidelines "Venous Access, 2019 (https://msestra.ru/download/file.php?id=4763) using the necessary medicinal products. Port systems are installed in accordance with Order of the Government of the Russian Federation No. 3053-r dated December 31, 2018, "On Approval of the List of Medical Devices Implanted in the Human Body When Providing Medical Care Within the Framework of the State Guarantee Program for Free Medical Care to Citizens, as Well as the List of Medical Devices Dispensed on Prescriptions for Medical Devices Upon Provision of a Set of Social Services."

The recommended dosing regimen depends on age. In children under 6 months of age, the recommended starting dose is 1 mg/kg; subsequently, in case of an insufficient response after at least 4 infusions, an increase in the dose to 3 mg/kg intravenously once a week should be considered [Instructions for Medical Use of sebelipase alfa**]. A further increase in the dose to 5 mg/kg once a week should be considered in case of an insufficient response after at least 4 additional infusions. Subsequent dose adjustments can be made individually depending on the achievement and maintenance of therapeutic goals; doses up to 7.5 mg/kg may be used (higher doses have not been studied) [21, 43, https://grls.rosminzdrav.ru/Grls_View_v2.aspx?routingGuid=1eaa9c5e-20c6-4a75-a48c-44f5271fcf4d].

The required volume of the drug is slowly diluted in the required volume of sodium chloride solution** according to weight (Appendix A3). The entire required volume of the solution must be administered over a period of at least 2 hours.

Attention should be paid to compliance with the intervals between infusions and the unacceptability of treatment interruptions, as non-compliance with the treatment regimen carries a potential risk of patient deterioration and progression of Wolman disease symptoms.

Monitoring of key disease progression parameters is necessary: assessment of mid-upper arm circumference, determination of alanine aminotransferase and aspartate aminotransferase activity in the blood, investigation of blood ferritin levels, investigation of serum C-reactive protein levels, coagulogram (screening hemostasis test), persistent or worsening organomegaly, frequent intercurrent infections, and persistent worsening of other symptoms (e.g., gastrointestinal) [https://grls.rosminzdrav.ru/Grls_View_v2.aspx?routingGuid=1eaa9c5e-20c6-4a75-a48c-44f5271fcf4d].

Comments: in patients with Wolman disease receiving ERT, as with the intravenous administration of any other protein product, adverse reactions may occur (fever, chills, vomiting, urticaria, severe allergic-type hypersensitivity reactions) occurring during the infusion or within a day after the infusion. If adverse reactions occur during or after the infusion, appropriate treatment is recommended, following current guidelines.

3.1.2 Pathogenetic treatment for cholesteryl ester storage disease (CESD) in patients older than 6 months

Comments: The drug for ERT is sebelipase alfa**. 1 ml of solution contains 2 mg of sebelipase alfa**. It is a recombinant form of human lysosomal acid lipase produced using recombinant DNA technology in chicken egg cell culture. ERT is intended to restore enzyme activity sufficient to hydrolyze accumulated cholesteryl esters and prevent their further accumulation. Following administration, sebelipase alfa** is rapidly cleared from the systemic circulation and taken up by cells, entering their lysosomes via mannose-6-phosphate receptors.

The drug is administered parenterally as intravenous infusions. Administration is carried out via a peripheral venous catheter (peripheral catheter) or a port system (implantable infusion/injection port***) installed in accordance with the methodological guidelines "Venous Access, 2019 (https://msestra.ru/download/file.php?id=4763) using the necessary medicinal products. Port systems are installed in accordance with Order of the Government of the Russian Federation No. 3053-r dated December 31, 2018, "On approval of the list of medical devices implanted in the human body when providing medical care within the framework of the state guarantee program for free medical care to citizens, as well as the list of medical devices dispensed on prescription for medical devices when providing a set of social services".

In children older than 6 months and adults, the drug is administered at a dose of 1 mg/kg every 2 weeks. Dosage increase up to 3 mg/kg once every 2 weeks is permitted based on clinical response. The required volume of the drug is slowly diluted in the appropriate volume of sodium chloride solution** according to weight (Appendix A3). The entire required volume of solution should be administered over approximately 2 hours. If the patient tolerates the drug well, a transition to a 1-hour infusion may be considered. In case of dose escalation, the duration of the infusion may be increased.

Attention should be paid to observing the intervals between infusions and avoiding interruptions in therapy, as treatment non-compliance carries a potential risk of clinical deterioration and progression of CESD symptoms.

Monitoring of the main parameters of the disease course is necessary.

Examination of siblings (brothers and sisters of the proband) may reveal asymptomatic children with LAL deficiency. Such patients require examination and monitoring, and their treatment must be initiated upon the appearance of the first clinical or laboratory symptoms of the disease.

Comments: in patients with CESD receiving ERT, as with the intravenous administration of any other protein product, adverse reactions may occur (fever, chills, vomiting, urticaria, severe allergic-type hypersensitivity reactions) occurring during the infusion or within a day after the infusion. If adverse reactions occur during or after the infusion, appropriate treatment is recommended, following current guidelines.

3.2 Symptomatic treatment

Includes prescribing a low-fat diet and treatment of comorbidities.

3.2.1 Symptomatic treatment in the infantile form of LAL-D (Wolman disease)

Comments: diagnosing hypovitaminosis and considering the need for therapy requires an appointment (examination, consultation) with an endocrinologist and/or gastroenterologist and/or dietitian.

3.2.2 Symptomatic treatment in cholesterol ester storage disease (CESD)

Comments: Methodological recommendations MR 2.3.1.2432-08 "Norms of physiological requirements for energy and nutrients for various population groups of the Russian Federation" have been adopted in the Russian Federation. Dietary fat restriction up to 30% of the energy value of the daily diet is permitted. The proportions of saturated, mono-, and polyunsaturated fats should be equal. The maximum allowable cholesterol amount is 300 mg/day, and it can be reduced to 200 mg/day. Protein levels should correspond to the physiological requirement standard depending on age, with an increased proportion of plant proteins. The recommended ratio of plant to animal protein is 1:1. Among animal proteins, preference should be given to fish. Easily digestible carbohydrates must be restricted while complex carbohydrates and plant fiber should be increased. In general, the proportion of carbohydrates should account for 50-60% of the energy value of the diet, of which 7-10% should be easily digestible.

Comments: diagnosing hypovitaminosis and considering the need for therapy requires an appointment (examination, consultation) with an endocrinologist and/or gastroenterologist and/or dietitian.

3.3 Surgical Treatment

3.3.1 Surgical treatment in the infantile form of LAL-D (Wolman disease)

Comments: Liver transplantation is also associated with a high risk of complications and does not affect the systemic manifestations of the disease. Liver transplantation does not stop the progression of Wolman disease and damage to other target organs. In addition, the risk of damage to the transplanted liver cannot be excluded, as LAL levels remain low.

Comment: The small number of clinical cases available for analysis does not allow for a definitive conclusion regarding the efficacy and safety of this therapy. In addition, the HSCT procedure is associated with a high risk of complications, such as graft rejection, graft-versus-host disease, and other postoperative complications. Therefore, HSCT is not recommended as a routine therapeutic option for patients with Wolman disease [33 - 36].

3.2.2 Surgical treatment for cholesteryl ester storage disease (CESD) manifesting at the age older than 6 months

Comments: Liver transplantation is also associated with a high risk of complications and does not affect the systemic manifestations of the disease. Liver transplantation does not halt the progression of CESD or damage to other target organs. In addition, the risk of damage to the transplanted liver cannot be excluded, as LAL activity remains low [30 – 32, 38].

3.4 Palliative care

Palliative care for patients with LALD is provided in accordance with relevant regulatory documents (see Appendix A3).

4. Medical Rehabilitation and Sanatorium-Resort Treatment

Patients with LALD (Wolman disease, CESD) and their families need psychological/medical psychology counseling, as the disease is progressive. It is necessary to help the patient "accept" the diagnosis and adapt to life to maximize their capacity for learning and independent living in the future [15].

5. Prevention and Dispensary Observation

5.1 Prevention

Comment: Families with children with LALD (Wolman disease and CESD) are recommended to undergo genetic counseling to determine genetic risk. As with other autosomal recessive disorders, in LALD (Wolman disease, CESD) the risk of having an affected child is 25% for each pregnancy. In families with a child with LALD, prenatal and preimplantation diagnostics are available. For this, parents should be referred to specialized diagnostic laboratories and medical centers.

Prenatal diagnostics of LALD

Comment: prenatal diagnostics is performed using molecular genetic or biochemical methods by analyzing DNA extracted from a chorionic villus biopsy at 9–11 weeks of pregnancy and/or amniotic fluid cells and fetal blood at 20–22 weeks of pregnancy.

5.2 Dispensary monitoring

5.2.1 Follow-up monitoring for patients with WD

Comments: patients with Wolman disease are characterized by a significant increase in transaminase activity (ALT, AST), hypercholesterolemia, hyperbilirubinemia, and possible hypertriglyceridemia; elevated LDL concentrations, and reduced HDL levels in many patients. Apolipoprotein profiling reveals an elevation in apolipoprotein B, the major LDL apolipoprotein, in the majority of patients.

Given the extreme rarity of Wolman disease, early onset, late diagnosis, and severe course, there are no reliable data on the required frequency of the test. The frequency of the general clinical biochemical blood test is dictated by the patient's condition.

Serial monitoring includes determining the activity of alanine aminotransferase and aspartate aminotransferase in the blood, measuring total bilirubin, conjugated bilirubin, cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and albumins in the blood (at least once a month).

Comment: if necessary, thrombin time and blood fibrinogen levels are also determined. These parameters allow monitoring of the synthetic function of the liver, detection of hepatocellular insufficiency syndrome, and timely prevention of complications associated with hemostatic disorders [49].

Comments: Abdominal ultrasound makes it possible to determine the size of the liver and spleen, determine the diameter of the portal and splenic veins, the presence of hepatic steatosis, fibrosis, or cirrhosis, and adrenal calcifications.

The frequency of comprehensive abdominal ultrasound and retroperitoneal space ultrasound (including adrenal ultrasound) is dictated by the patient's condition, but should be at least once a month

Comments: performing EGD in patients with liver fibrosis and signs of portal hypertension is necessary to assess the degree of esophageal varices and the risk of bleeding.

Comment: patients with Wolman disease are followed by a gastroenterologist and/or pediatrician (at least once a month), as well as a geneticist; a consultation with a clinical nutritionist is required to prescribe a low-fat diet and correct malabsorption (selection of a specialized diet with restriction of animal fats, and in some situations, parenteral nutrition) [2,15], a pediatric cardiologist to assess cardiovascular disorders and therapy [2,13,15,20,26], a neurologist to assess nervous system disorders [14], and a transplant specialist if indications for liver transplantation are present. In life-threatening conditions, the participation of an anesthesiologist-resuscitologist is necessary.

5.2.2 Follow-up monitoring for patients with CESD

Comments: As part of the complete blood count with differential, it is necessary to determine: total hemoglobin, erythrocyte, leukocyte, and platelet counts, differential leukocyte count (leukocyte formula), blood smear review to analyze erythrocyte, platelet, and leukocyte morphological abnormalities, color index determination, measurement of erythrocyte size, and erythrocyte sedimentation rate. The pathogenetic mechanisms of anemia and thrombocytopenia are not fully understood. One of the possible mechanisms is the accumulation of cholesterol esters and triglycerides in cells of the macrophage-monocyte system. In addition, anemia may be nutritional and deficiency-related or result from hypersplenism. Thrombocytopenia is a consequence of hypersplenism during the development of portal hypertension, alongside reported cases of secondary hemophagocytic lymphohistiocytosis.

Comments: most patients with CESD exhibit elevated transaminase activity (ALT, AST), hypercholesterolemia, hypertriglyceridemia, and increased LDL concentration, while many patients have decreased blood HDL levels. Apolipoprotein profiling reveals an elevated level of apolipoprotein B, the main apolipoprotein of LDL.

Comment: if necessary, thrombin time and blood fibrinogen levels are also determined. These indicators allow monitoring of synthetic liver function, detection of hepatocellular insufficiency syndrome, and timely prevention of complications associated with hemostatic disorders [49].

Comments: Liver and spleen ultrasound can detect hepatomegaly and, less frequently, splenomegaly, as well as hepatic steatosis, fibrosis, or cirrhosis. Retroperitoneal ultrasound, including adrenal ultrasound, may reveal adrenal calcifications (extremely rare in patients with CESD, no more than 5%).

Comments: evaluation of the severity of fatty liver disease (via MRI) is necessary for subsequent monitoring of ERT efficacy. Average frequency of examinations: abdominal MRI – once a year, liver elastography – once every 6 months.

Comments: performing EGD in patients with hepatic fibrosis and signs of portal hypertension is necessary to assess the grade of esophageal varices and bleeding risk

Comment:

In the presence of arrhythmia, it is necessary to perform 24-hour Holter ECG monitoring, and stress testing (exercise electrocardiography) as clinically indicated, in accordance with the guidelines for the management of patients with atherosclerosis and arrhythmia.

Comment: patients with CESD are followed up by a gastroenterologist, general practitioner (or pediatrician in pediatric practice), and a geneticist. A consultation with a nutritionist is required to prescribe a low-fat diet (selection of a specialized diet with restriction of animal fats) [2, 15]; a consultation with a cardiologist (pediatric cardiologist) to assess cardiovascular disorders and therapy (assessment of vascular risk, prescription of treatment, initially and subsequently every 6 months) [2, 13, 15, 20, 26]; and a transplant surgeon consultation if indications for liver transplantation are present. In the presence of neurological disorders: a neurologist consultation (initially and then annually). In life-threatening conditions, the involvement of an anesthesiologist-intensivist is required. Initial and repeat consultations with other specialists, as well as a medical psychologist, are indicated for patients with LAL-D who have impaired functions of other organs and systems.

6. Organization of Medical Care

Indications for planned hospitalization:

- provision of diagnosis and treatment requiring round-the-clock medical supervision;

- a condition requiring active treatment and round-the-clock medical supervision;

- a condition requiring high-tech treatment methods;

- lack of capability to provide ERT in outpatient and day-care settings;

- the need for various types of expert evaluations or examinations in a medical organization when they cannot be performed on an outpatient basis and require dynamic observation (including issuing a federal medical board conclusion).

Indications for emergency hospitalization:

- acute diseases;

- exacerbations of chronic diseases;

- poisoning and injuries, conditions requiring intensive care and transfer to intensive care units or critical care units (including adverse reactions occurring during infusion or within 24 hours of ERT infusion, and other life-threatening acute conditions), as well as round-the-clock medical supervision and special diagnostic and therapeutic procedures.

Indications for patient discharge from a medical organization:

- absence of a threat to the patient's life;

- absence of a threat of complications requiring urgent treatment;

- stabilization of the patient's condition and main clinical and laboratory parameters of the pathological process regarding the underlying disease;

- no need for constant physician and round-the-clock medical supervision regarding the underlying disease;

- the need to transfer the patient to another hospital or social welfare institution.

Principles of organizing medical care for patients with LAL deficiency

Establishing a diagnosis of LAL deficiency raises many questions for the patient's relatives and specialists working with such patients. Numerous problems arise upon the detection and progression of the disease, which require competent organization of the care process with the participation of a multidisciplinary team of specialists and adherence to the basic principles and approaches of its delivery.

These principles must be observed at any stage of medical care, both at the time of diagnosis and at any stage of patient follow-up.

1) The patient and their representatives must receive complete information about the disease, its course, pathogenesis, prognosis, complications, and potential therapy methods.

2) The diagnosis of LAL deficiency implies the possibility of providing primary, specialized, and palliative care at all stages of the disease.

3) Upon establishing a diagnosis of LAL deficiency, the family should be referred to a specialist experienced in working with patients with this disease, possessing up-to-date information on the disease course and the possibility of participating in clinical trials (of new drugs and/or medical devices). It is also important to inform families about existing patient advocacy organizations operating with this group of patients.

Specifics of organizing medical care for patients with the infantile form of LAL deficiency (Wolman disease)

Given the rapid progression of LAL-D, all children with this diagnosis need inpatient monitoring, with transfer to an intensive care unit if necessary, where treatment for severe progressive liver failure is carried out in accordance with relevant clinical guidelines.

- In LAL-D, patients are monitored by a gastroenterologist (and/or pediatrician) and a geneticist. A consultation with a nutritionist is required to prescribe a low-fat diet, and in some situations, parenteral nutrition [2, 15]. Consultations are indicated with a cardiologist (pediatric cardiologist) to assess cardiovascular disorders and prescribe treatment [2, 13, 15, 20, 26], an endocrinologist to assess adrenal function and timely prescribe hormone replacement therapy, a neurologist to assess nervous system disorders, and a transplant surgeon if indications for liver transplantation are present. In life-threatening conditions, the involvement of an anesthesiologist-intensivist is required.

Specifics of organizing medical care for patients with CESD

In CESD, patients are monitored by a gastroenterologist, general practitioner (and/or pediatrician in pediatric practice), or general family physician. On average, once every 6–12 months (depending on the severity of the condition), a comprehensive examination is indicated on an outpatient basis, in a day hospital, and in multidisciplinary hospitals.

In addition, a geneticist and a nutritionist consultation are required to prescribe a low-fat diet (selection of a specialized diet restricting animal fats) [2, 15]; a cardiologist (pediatric cardiologist) consultation to assess cardiovascular disorders and therapy (vascular risk assessment, prescription of treatment) [2, 13, 15, 20, 26]; and a transplant surgeon consultation if indications for liver transplantation are present. In life-threatening conditions, the involvement of an anesthesiologist-intensivist is required.

Other specialists should be involved as specific problems arise.

7. Additional Information

The prognosis in CESD depends on the age of disease onset and the severity of clinical manifestations. Timely diagnosis and the administration of pathogenetic therapy in the early stages of the disease determine a favorable prognosis and improve the quality of life of children with CESD by preventing the development of liver cirrhosis.

In the infantile form of LAL deficiency (Wolman disease), without ERT, the prognosis is unfavorable (death under the age of 6 months).

Criteria for Evaluating the Quality of Medical Care

when providing specialized medical care

Quality criteria for LAL-D

Quality criteria for CESD

References

Appendix A1. Working Group Composition

1. Inga V. Anisimova, Candidate of Medical Sciences, Head of the Department of Medical Care Organization, Medical Geneticist, Research Centre for Medical Genetics named after Academician N.P. Bochkov, Member of the Association of Medical Geneticists.

2. Marina B. Albegova, Candidate of Medical Sciences, Head of the Consultative and Pediatric Department of the Department of Pediatrics, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov

3. Madlena E. Bagaeva, Candidate of Medical Sciences, Senior Researcher, Department of Pediatric Gastroenterology, Hepatology and Dietotherapy, Clinic of the Federal Research Centre of Nutrition and Biotechnology

4. Galina V. Baydakova, Candidate of Biological Sciences, Leading Researcher, Laboratory of Inherited Metabolic Diseases, Research Centre for Medical Genetics named after Academician N.P. Bochkov, Member of the Russian Society of Medical Geneticists.

5. Alexander A. Baranov, 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 in Central Clinical Hospital of the Russian Academy of Sciences, Chief Freelance Pediatrician of the Russian Ministry of Health.

6. Nato D. Vashakmadze, Doctor of Medical Sciences, Head of the Department of Rare Diseases, Research Institute of Pediatrics and Child Health in Central Clinical Hospital of the Russian Academy of Sciences, Member of the Union of Pediatrists of Russia

7. Elena A. Vishneva, Doctor of Medical Sciences, Deputy Head for Science, Research Institute of Pediatrics and Child Health in Central Clinical Hospital of the Russian Academy of Sciences, Associate Professor, Department of Faculty Pediatrics, Pediatric Faculty, Pirogov Russian National Research Medical University of the Russian Ministry of Health

8. Olga S. Gundobina, Candidate of Medical Sciences, Gastroenterologist, Research Institute of Pediatrics and Child Health in Central Clinical Hospital of the Russian Academy of Sciences, Member of the Union of Pediatrists of Russia

9. Anna V. Degtyareva, Doctor of Medical Sciences, Professor, Head of the Department of Pediatrics, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov, Professor of the Department of Neonatology, Institute of Child Health, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University).

10. Marat V. Ezhov, Doctor of Medical Sciences, Professor, Chief Researcher, Department of Atherosclerosis Problems, Myasnikov Research Institute of Clinical Cardiology, National Medical Research Center of Cardiology of the Russian Ministry of Health

11. Maria S. Zharkova, Candidate of Medical Sciences, Head of the Hepatology Department, Clinic of Propedeutics of Internal Diseases, Gastroenterology and Hepatology named after V.H. Vasilenko, University Clinical Hospital No. 2, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)

12. Natalia V. Zhurkova, Candidate of Medical Sciences, Leading Researcher, Department of Orphan Diseases and Prevention of Disabling Conditions, Medical Geneticist, Research Institute of Pediatrics and Child Health in Central Clinical Hospital of the Russian Academy of Sciences, Member of the Association of Medical Geneticists (AMG).

13. Ekaterina Yu. Zakharova, Doctor of Medical Sciences, Head of the Laboratory of Inherited Metabolic Diseases, 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).

14. Vladimir T. Ivashkin, Academician of the Russian Academy of Sciences, Professor, Doctor of Medical Sciences, Head of the Department of Propedeutics of Internal Diseases, Director of the Clinic of Propedeutics of Internal Diseases, Gastroenterology and Hepatology named after V.H. Vasilenko, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)

15. Elena A. Kamanets, Staff Member, Laboratory of Inherited Metabolic Diseases, Research Centre for Medical Genetics named after Academician N.P. Bochkov, Member of the Russian Society of Medical Geneticists.

16. Sergey I. Kutsev, Academician of the Russian Academy of Sciences, Doctor of Medical Sciences, Director, Research Centre for Medical Genetics named after Academician N.P. Bochkov, President of the Association of Medical Geneticists (AMG).

17. Alla E. Lavrova, Doctor of Medical Sciences, Chief Researcher, Highest Qualification Category Physician in Pediatrics, Head of the 2nd Pediatric Department with Medical Rehabilitation, Privolzhsky Research Medical University of the Russian Ministry of Health

18. Irina A. Matinyan, Candidate of Medical Sciences, Researcher, Department of Pediatric Gastroenterology, Hepatology and Dietotherapy, Clinic of the Federal Research Centre of Nutrition and Biotechnology

19. Svetlana V. Mikhailova, Doctor of Medical Sciences, Head of Department, Russian Children's Clinical Hospital of the Russian Ministry of Health.

20. Leyla S. Namazova-Baranova, 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 in Central Clinical Hospital of the Russian Academy of Sciences, 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

21. Irina E. Pashkova, Candidate of Medical Sciences, Head of the Pediatric Department, National Medical Research Center of Transplantology and Artificial Organs named after Academician V.I. Shumakov of the Russian Ministry of Health

22. Elena E. Petryaikina, Doctor of Medical Sciences, Director of the Russian Children's Clinical Hospital, Pirogov Russian National Research Medical University of the Russian Ministry of Health, Professor of the Department of Faculty Pediatrics, Pediatric Faculty, Pirogov Russian National Research Medical University, Professor of the Department of Evidence-Based Medicine, Medical Institute of RUDN University, Chief Freelance Pediatric Endocrinologist of the Moscow Healthcare Department

23. Tatyana M. Pervunina, Candidate of Medical Sciences, Director of the Institute of Perinatology and Pediatrics, Almazov National Medical Research Centre of the Russian Ministry of Health

24. Natalia L. Pechatnikova, Neurologist, Head of Department, Morozov Children's City Clinical Hospital of the Moscow Healthcare Department

25. Svetlana A. Repina, Candidate of Medical Sciences, Medical Geneticist, Research Centre for Medical Genetics named after Academician N.P. Bochkov, Member of the Russian Society of Medical Geneticists, Member of the Association of Medical Geneticists.

26. Liliya R. Selimzyanova, Candidate of Medical Sciences, Leading Researcher, Research Institute of Pediatrics and Child Health in Central Clinical Hospital of the Russian Academy of Sciences of the Ministry of Science and Higher Education of the Russian Federation, Associate Professor of the Department of Pediatrics and Pediatric Rheumatology, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)

27. Tamara A. Skvortsova, 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, Morozov Children's City Clinical Hospital of the Moscow Healthcare Department

28. Tatyana V. Strokova, Doctor of Medical Sciences, Professor of the Russian Academy of Sciences, Head of the Department of Pediatric Gastroenterology, Hepatology and Dietotherapy, Clinic of the Federal Research Centre of Nutrition and Biotechnology

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

30. Andrey N. Surkov, MD, DSc, Head of the Gastroenterology Department with Hepatology Group, National Medical Research Center for Children's Health of the Russian Ministry of Health

31. Elena L. Tumanova, MD, DSc, Professor, Head of the Department of Pathological Anatomy, Pirogov Russian National Research Medical University of the Russian Ministry of Health

32. Ekaterina G. Tsimbalova, PhD, freelance specialist of the Ministry of Health of the Moscow Region — Chief Pediatric Gastroenterologist of the Moscow Region, member of the Union of Pediatricians of Russia, member of the pediatric working group of the Russian Organization for the Study of IBD.

Patient community representative:

33. Nelli S. Pogosyan – Representative of the All-Russian Organization for Rare Diseases

The authors declare no financial support or conflicts of interest that need to be disclosed.

Appendix A2. Methodology for Developing Clinical Guidelines

These guidelines are intended for use by medical organizations and institutions of federal, territorial, and municipal healthcare management systems, compulsory and voluntary medical insurance systems, and other medical organizations of various legal forms engaged in the provision of medical care.

These guidelines establish the types, scope, and quality indicators of medical care for patients with LAL deficiency and were reviewed on June 1–2, 2018, at the Scientific and Practical Congress "Rare Diseases" in Moscow.

The clinical guidelines are based on a systematic literature review of 1992–2019 from Medline (PubMed version), Embase (Dialog version), and Cochrane Library databases, as well as current international clinical guidelines for the diagnosis, treatment, and management of patients with metabolic diseases.

Lysosomal acid lipase deficiency is a rare hereditary disease, which precludes large-scale cohort and randomized controlled trials; therefore, protocol development for diagnosis and treatment relies solely on expert case studies published over the past two decades.

The evaluation of the quality of evidence and the strength of recommendations for the application of medical technologies was performed in accordance with the standardized scale presented in Tables 1–3.

Target audience for these clinical guidelines:

1. General practitioners (family physicians);

2. Pediatricians;

3. Gastroenterologists;

4. Internists;

5. Medical geneticists;

6. Laboratory geneticists;

7. Cardiologists;

8. Pediatric cardiologists;

9. Neurologists;

10. Radiologists;

11. Functional diagnostics physicians;

12. Medical psychologists;

13. Medical students;

14. Medical residents.

Table 1. Level of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)

Table 2. Scale for assessing levels of reliable evidence (LRE) for prevention, treatment, and rehabilitation methods (preventive, therapeutic, rehabilitation interventions)

Table 3. Grade of Recommendation (GoR) scale for prevention, diagnostic, treatment, and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitative interventions)

Procedure for updating clinical guidelines.

The mechanism for updating 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 on the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

1. Federal Law No. 323-FZ of November 21, 2011, "On the Fundamentals of Healthcare Protection in the Russian Federation".

2. Order of the Russian Ministry of Health No. 274n of April 21, 2022, "On Approval of the Procedure for Providing Medical Care to Patients with Congenital and (or) Hereditary Diseases".

3. 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"

4. Order of the Ministry of Health of the Russian Federation No. 906n dated November 12, 2012, "On Approval of the Procedure for Providing Medical Care to the Population Profile 'Gastroenterology'"

Drug information: 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."

Other regulatory and legal documents used in the development of the clinical guidelines:

1. Federal Law No. 323-FZ dated November 21, 2011, "On the Basics of Protecting the Health of Citizens in the Russian Federation" (Collected Legislation of the Russian Federation, 2011, No. 48, Art. 6724);

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

3. Order of the Ministry of Health of the Russian Federation No. 1183n dated December 20, 2012, "On Approval of the Nomenclature of Positions for Medical and Pharmaceutical Workers";

4. Order of the Russian Ministry of Health No. 103n dated February 28, 2019, "On approval of the procedure and timelines for the development of clinical guidelines, their revision, the standard template of clinical guidelines, and requirements for their structure, composition, and scientific validity of the information included in the clinical guidelines."

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

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

Comparison of manifestations of the infantile form of LAL deficiency (Wolman disease) and cholesteryl ester storage disease (CESD)

Differential diagnosis of NAFLD and LAL deficiency

Sampling of biological material for dried blood spot testing

Algorithm of actions for medical personnel during blood sample collection

· wash hands (hygienic level), put on gloves;

· wash the patient's hands (the infant's heel if blood is collected from the heel);

· wipe the puncture site with a sterile wipe soaked in 70% alcohol, blot with a dry sterile wipe; — puncture with a single-use sterile lancet;

· wipe away the first drop of blood with a sterile dry swab;

· apply gentle pressure to obtain a second drop of blood;

· apply the test card perpendicularly to the drop of blood and saturate it completely with blood;

· similarly, apply 6-8 drops of blood to the test card; the blood spots must look identical on both sides.

· dry the test card in a horizontal position on a clean, grease-free surface for at least 4 hours without heat treatment or exposure to direct sunlight;

· pack the test cards in a clean envelope so that the blood spots do not touch.

Specifics during infusion therapy

Some patients may receive infusion therapy or blood component transfusions, which can affect test results. For example, blood plasma transfusions may yield false-negative results because the enzymes being measured are present in plasma and blood cells. It is recommended to collect blood for enzyme and DNA testing no earlier than 6–7 days after a blood plasma transfusion and 7–10 days after a blood component transfusion.

Blood sampling is not permitted

· immediately after the patient undergoes infusion therapy;

· immediately after replacement blood transfusion.

Storage and transportation of biological material

Dried blood spot samples can be stored in a standard refrigerator chamber at +4°C until shipment. The storage period prior to shipment should not exceed 7 days. Longer storage or higher temperatures may reduce enzyme activity even in healthy individuals, leading to false-positive results.

Recommended administration volumes of sebelipase alfa**

* The infusion volume should be based on the prescribed dose and prepared to a final sebelipase alfa** concentration of 0.1–1.5 mg/mL.

(dose 1 mg/kg) (https://grls.rosminzdrav.ru/)

Note legend

…** – the drug is included in the list of vital and essential drugs (Decree of the Government of the Russian Federation No. 2406-r dated October 12, 2019 "On Approval of the List of Vital and Essential Drugs for 2020, as Well as Lists of Medicinal Products for Medical Use and the Minimum Assortment of Medicinal Products Required for Medical Care")

# - off-label use – outside the indications registered in the drug instructions, carried out by decision of the medical commission, with the permission of the Local Ethics Committee of the medical organization (if any), subject to the signed informed consent of the parents (legal representative) and the patient over 15 years of age;

*** - a medical device implanted into the human body during the provision of medical care within the framework of the state guarantee program of free medical care to citizens.

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

Why does the disease occur?

CESD is a hereditary disease associated with mutations in the LIPA gene.

Genes consist of DNA sequences that contain instructions for "making" proteins or RNA (ribonucleic acid). Genes are located in chromosomes. Humans have 23 pairs of chromosomes: one chromosome with the corresponding set of genes is inherited from the mother, and the second from the father. There are also two special chromosomes that determine the sex of the child — girls have two X chromosomes, while boys have one X and one Y chromosome.

The LIPA gene is located on chromosome 10.

CESD is inherited in an autosomal recessive manner, meaning that both parents are carriers of the mutation but do not have the disease because they have a second healthy copy of the gene. A child with CESD inherits one "mutated" copy of the gene from the father and one from the mother. The disease manifests only if two copies of the damaged gene are present. The risk of having a child with CESD in this case is 25%. Boys and girls are affected with equal frequency. Disease carriers inherit only one copy, either from the father or the mother. They do not have the disease and show no signs of it.

What metabolic processes are impaired in CESD?

In CESD, the lysosomal acid lipase (LAL) enzyme does not function, leading to the accumulation of large molecules such as triglycerides and cholesteryl esters in special cellular organelles called lysosomes. Normally, triglycerides and cholesteryl esters are broken down in lysosomes, and the resulting fatty acids and cholesterol are utilized by the body to build new cells and provide energy. In patients with CESD, due to insufficient LAL activity, cells become so overloaded with undigested molecules that they cease to function properly. The largest number of such non-functioning cells is found in the liver, spleen, blood vessel walls, and adrenal glands, though other organs and tissues are also affected. Over time, for example, the liver significantly increases in size, loses function, and becomes replaced by connective tissue, progressing to cirrhosis. Elevated blood cholesterol levels are associated with an increased risk of heart disease and a range of other conditions caused by impaired arterial patency.

How does CESD manifest?

First described by M. Wolman as separate disorders—infantile CESD (Wolman disease) (in 1956) and cholesterol ester storage disease (in 1963)—they are now considered clinical forms of CESD.

The age of onset and rate of disease progression are highly variable and may depend on the nature of the underlying mutations.

In the infantile form of CESD (Wolman disease), infants experience profound growth and development failure, liver fibrosis, and cirrhosis; children die from liver failure at an early age.

In the late-onset form of CESD (CESD), children and adults present with a combination of

dyslipidemia (impaired lipid balance in the body), hepatomegaly (enlarged liver), elevated transaminases (enzymes whose levels rise in liver diseases), and microvesicular steatosis (accumulation of fat droplets in liver cells).

In children and adults with CESD, progression to fibrosis, cirrhosis, or the need for liver transplantation occurs in approximately 50% of cases within 3 years of symptom onset. Cardiovascular complications due to early atherosclerosis may manifest starting in childhood.

A diagnosis of CESD may be suspected in the presence of liver abnormalities (hepatomegaly, elevated transaminase activity, signs of steatosis) and lipid profile disturbances. The difficulty in diagnosis lies in the absence or paucity of patient complaints, despite the progression of the pathological process in the liver and other organs. In many cases, CESD is found incidentally during routine general biochemical blood tests or liver ultrasound examinations. Nevertheless, various organs, predominantly the liver, lose their functionality. Because the body can function for some time even with a small portion of the liver remaining, some CESD patients are diagnosed only at the late stages of cirrhosis, when any stressor can result in complete liver failure and even death.

Liver-related:

• Fibrosis

• Cirrhosis

• Portal hypertension

• Liver failure

Cardiovascular:

• Accelerated atherosclerosis

• Coronary artery disease

• Stroke

• Myocardial infarction

Spleen-related:

• Anemia

• Thrombocytopenia

• Risk of traumatic splenic rupture and/or splenectomy

Gastrointestinal involvement

• Abdominal pain

• Digestive disorders

• Growth retardation

What are the complications of this disease?

As CESD progresses, liver failure may develop. Due to impaired fat and cholesterol metabolism, atherosclerosis can develop, leading to heart attacks and strokes. Anemia and a low platelet count, resulting in frequent bleeding, are complications of CESD associated with impaired splenic function.

How is CESD diagnosed in the laboratory?

Doctors may suspect the disease based on clinical symptoms. Subsequently, laboratory tests and instrumental examinations are performed. The diagnosis of CESD is confirmed by detecting a significant deficiency in enzyme activity. LAL activity is assessed by measuring enzyme activity in dried blood spots on filter paper. This method virtually unmistakably indicates CESD, as patients have LAL activity reduced by tens or hundreds of times, or sometimes completely absent in severe forms. No other conditions are known to cause such low LAL activity. The blood test for LAL can serve as a tool in screening programs and large population studies of CESD, and can also be adapted for newborn screening. If enzyme activity is reduced, DNA diagnostics are performed to identify mutations in the LIPA gene. In this disease, patients are found to have two mutations in the gene. These can be in a homozygous state (two identical mutations) or a compound heterozygous state (two different mutations).

A diagnosis can be established solely on the basis of laboratory testing.

What is the prognosis for patients with CESD?

Without treatment, the prognosis is unfavorable. Infants with the infantile form of CESD (Wolman disease) die within the first six months of life.

In half of children and adults with the slowly progressive form of the disease (cholesterol ester storage disease), liver damage becomes so severe within 3 years of symptom onset that fibrosis, cirrhosis, or liver transplantation is required.

How are patients with CESD treated?

A treatment has recently become available in the form of a recombinant lipase enzyme. This drug is called "Sebelipase alfa**" and is already registered in Russia. The essence of the treatment is very simple: the missing enzyme is administered to the patient, causing sebelipase alfa** to break down the accumulated substances and halt disease progression.

Is enzyme replacement therapy lifelong, or can one undergo a few courses and cure the disease?

Enzyme replacement therapy with sebelipase alfa** is lifelong and significantly improves the prognosis of the disease, enhances the quality of life of children with CESD, and prevents the development of liver cirrhosis. Unfortunately, the intravenously administered enzyme has a limited lifespan in the body, and its deficiency must be continually replenished.

Sebelipase alfa** is prescribed once every two weeks for children and adults, and once a week for infants. The dose is 1 mg/kg, calculated based on the child's weight. The drug is administered intravenously. Dose adjustment is carried out if the child's weight decreases or increases.

What should be watched out for when prescribing sebelipase alfa**?

3% of patients in clinical trials reported signs and symptoms of anaphylaxis, i.e., a severe allergic reaction. Therefore, infusions of sebelipase alfa** must be administered by a trained healthcare professional capable of managing severe allergic reactions. If such reactions develop, the administration of the drug must be stopped immediately and appropriate treatment initiated.

Can the disease be treated with other drugs—those that lower cholesterol or support liver function?

This therapy was used before the advent of a drug capable of altering the course of the disease. Unfortunately, such treatment is symptomatic, has an unstable and short-lived effect, and does not affect disease outcomes. Furthermore, no studies have been conducted demonstrating the efficacy of this therapy. However, it should be noted that one of the therapeutic approaches remains relevant today and improves the condition of patients with LAL deficiency: a low-fat diet. Nevertheless, without enzyme replacement therapy, its efficacy will be insufficient.

Table 1. Examination of patients with LAL deficiency

In addition, follow-up examinations in an inpatient or day-care setting should be performed 2 times a year to evaluate treatment efficacy.

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

Not applicable.