Hereditary Spherocytosis: Clinical Guidelines

List of Abbreviations

2,3-DPG – 2,3-diphosphoglycerate

ALT – alanine aminotransferase

AST – aspartate aminotransferase

LDH – lactate dehydrogenase

MRI – magnetic resonance imaging

HS – hereditary spherocytosis

TSAT – transferrin saturation

TIBC – total iron-binding capacity

EOF – erythrocyte osmotic fragility

SCD – sickle cell disease

TEC – transient erythroblastopenia of childhood

ALP – alkaline phosphatase

EMA test – eosin-5-maleimide fluorescence dye test

CDAII – congenital dyserythropoietic anemia type II

Hb – hemoglobin

HbF – fetal hemoglobin

HPP – hereditary pyropoikilocytosis

Ig – immunoglobulin

MCH – mean corpuscular hemoglobin

MCHC – mean corpuscular hemoglobin concentration

MCV – mean corpuscular volume

MSCV – mean spherical cell volume

RDW – red cell distribution width, anisocytosis index

SAO – Southeast Asian ovalocytosis

Terms and Definitions

Anemia – a decrease in blood hemoglobin levels.

Aplastic crisis – a condition characterized by massive destruction of erythroid precursors in the bone marrow.

Vaccine prophylaxis – administration of vaccines for the prevention of infections.

Hemolysis – destruction of red blood cells.

Hepatobiliary disorders – disorders of the hepatobiliary system, which is a complex multilevel mechanism of interaction between the liver, bile ducts, and gallbladder.

Hepatic glucurononyltransferase system – the liver enzyme system that catalyzes the glucuronidation (conjugation) of bilirubin.

Jaundice – (lat. icterus) — yellowish discoloration of the skin and visible mucous membranes caused by elevated levels of bilirubin in the blood and tissues.

Erythrocyte ovalocytosis index – the ratio of the maximum length to width of erythrocytes, measured using hardware-software systems or an ocular micrometer.

Erythrocyte sphericity index – the ratio of the mean diameter to the thickness of erythrocytes.

Price-Jones curve – a histogram of the distribution of erythrocytes by diameter, defined as the half-sum of the maximum length and width of erythrocytes measured using hardware-software systems or an ocular micrometer.

Cryohemolysis – impaired transport of monovalent cations into erythrocytes at low temperatures, leading to erythrocyte destruction.

Hereditary spherocytosis (synonyms: Minkowski-Chauffard syndrome, Minkowski-Chauffard anemia, hereditary spherocytic hemolytic anemia) – an inherited hemolytic anemia caused by an erythrocyte membrane defect resulting in a characteristic change in erythrocyte shape (spherocytes), which is heterogeneous in severity of clinical manifestations, membrane protein defects, and inheritance pattern.

Unconjugated – bilirubin that has not undergone conjugation in hepatocytes, i.e., indirect bilirubin.

Obstructive jaundice – jaundice caused by impaired bile outflow through extrahepatic bile ducts.

Erythrocyte osmotic resistance – resistance to hypotonic NaCl solutions of varying concentrations ranging from 0.9% to 0.22%.

Penicillin prophylaxis – prevention of infections caused by penicillin-sensitive microorganisms by prescribing penicillin antibiotics.

Reticulocytosis – an increased number of reticulocytes in peripheral blood.

Reticulocytopenia – a decreased number of reticulocytes in peripheral blood.

Splenomegaly – enlargement of the spleen.

Splenectomy – surgical removal of the spleen.

Warm agglutinins – antibodies belonging to the IgG class that cause erythrocyte aggregation at 37^oC and above, followed by their destruction.

Thrombophilia – a pathological condition characterized by impaired blood coagulation, leading to an increased risk of thrombosis.

Chelator – a substance that forms a stable, non-toxic compound with a metal (in this case, iron) capable of leaving the body.

Chelation therapy – the therapeutic use of chelators.

Cholelithiasis – gallstones.

Cold agglutinins – antibodies, most commonly belonging to the IgM class, that cause erythrocyte aggregation upon exposure to low temperatures, followed by their destruction involving the complement system.

Erythrocyte cytoskeleton – a network of interconnected erythrocyte membrane proteins.

Ektacytometry – a method for studying erythrocyte deformability.

Endovascular occlusion – blockage of blood vessels with special sclerosing agents (emboli) injected directly into the target site of an artery.

Erythrocyte indices – indices obtained on an automated hematological analyzer during peripheral blood analysis: MCV, MCH, MCHC, RDW.

Erythrocytometry – measurement of erythrocyte dimensions with calculation of the mean erythrocyte diameter, erythrocyte sphericity index, erythrocyte ovalocytosis index, and plotting of the Price-Jones curve.

de novo – newly arisen (translated from Latin).

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Hereditary spherocytosis – an inherited hemolytic anemia caused by a genetically determined erythrocyte membrane defect resulting in a characteristic change in erythrocyte shape (spherocytes), which is heterogeneous in severity of clinical manifestations, membrane protein defects, and inheritance pattern [1-5].

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

The altered morphology and shortened lifespan of erythrocytes in HS are associated with a deficiency or dysfunction of one of the erythrocyte cytoskeleton elements, whose functions are to maintain shape, deformation resistance, and erythrocyte elasticity [1-6]. The erythrocyte cytoskeleton is a spectrin-based protein network (constituting about 65% of the erythrocyte surface) located on the lipid bilayer of the cytoplasmic membrane (Fig. 1) [2,6]. Each spectrin monomer (alpha and beta) consists primarily of repeating units (106 amino acids long) that fold into a triple helix. Joined alpha/beta spectrin heterodimers form face-to-face aligned tetramers, while the other end of the spectrin heterodimer is bound to protein band 4.1 and actin. Two transmembrane proteins, band 3 protein and glycophorin C, are involved in vertical attachment to the lipid bilayer. Band 3 protein, existing as a dimer and tetradimer in situ in erythrocytes, has multiple protein-binding domains. It can interact with ankyrin, which binds to the beta-subunit of spectrin. In addition, to bind to protein band 4.1 at its N-terminal cytoplasmic domain, band 3 protein interacts with protein band 4.2, which provides additional stability to the cytoskeleton. Glycophorin C interacts with protein p55 and protein band 4.1, which in turn binds to the beta-subunit of spectrin. Thus, deficiency or dysfunction of any of these membrane components within the vertical linkage can weaken or destabilize the cytoskeleton, leading to impaired erythrocyte morphology and a shortened lifespan [2,6].

It is hypothesized that coordinated movements of the lipid bilayer and the protein cytoskeleton in the vertical and horizontal directions provide erythrocyte membrane elasticity and deformability in circulation [6].

Deficiency or dysfunction of one or more vertical cytoskeleton proteins (band 3, band 4.2, ankyrin, alpha- or beta-spectrin) leads to impaired vertical interaction and detachment of the bilipid layer from the cytoskeleton [2,5,6]. According to erythrocyte membrane protein electrophoresis in hereditary spherocytosis (HS), a deficiency of one or several proteins is typically present [1-6]. A marked reduction in membrane surface area leads to the development of hemolytic anemia.

During the neonatal period, when erythrocytes contain high levels of HbF, conditions are created for greater instability of the erythrocyte membrane in HS, because HbF is unable to bind free 2,3-diphosphoglycerates (2,3-DPG), which exert a destabilizing effect on the interaction between spectrin and band 4.1 protein, thereby leading to erythrocyte membrane instability [5,6].

1.3 Epidemiology of the Disease or Condition

The incidence of hereditary spherocytosis is 1:5,000 live births of both sexes; including mild and subclinical forms, it is 1:2,000 live births of both sexes [1,3,5].

Inheritance of HS is autosomal dominant in approximately 75% of cases, with the remaining 25% being autosomal recessive and de novo cases [3,5].

A complication of HS is cholelithiasis, the onset of which typically occurs between the ages of 2 and 4 years [1-5,7]. With age, the frequency of cholelithiasis increases, reaching 30% by the age of 18 [1,2,7]. The prevalence of this complication depends on the patients' dietary habits (patients whose diet is rich in plant fiber are less prone to cholelithiasis) and the disease genotype. Third-generation cephalosporins can crystallize within the gallbladder lumen; differences in the use of such antibiotics may explain some geographical variations in the incidence of cholelithiasis.

Rare complications of HS also include growth retardation, which is associated with tissue hypoxia and expansion of the sites of hematopoiesis, and may be observed only in severe and moderately severe forms of HS [1,2,5,7].

Several cases of extramedullary hematopoietic foci have been described in adult patients with severe HS and an unremoved spleen [1,2,5,7].

1.4 Features of Coding the Disease or Condition

D58.0 – Hereditary spherocytosis; Minkowski-Chauffard syndrome

D58.8 – Other specified hereditary hemolytic anemias

D58.9 – Hereditary hemolytic anemia, unspecified

1.5 Classification of the disease or condition

Depending on the clinical course, the disease is conventionally subdivided into [1,2]:

• crisis course

• chronic hemolysis

by severity:

• asymptomatic form

• subclinical form

• mild form

• moderately severe form

• severe form

2. Diagnostics, medical indications and contraindications for diagnostic methods

The diagnosis of HS is established based on clinical manifestations and laboratory test results (Table 2) [1-5,7-14,31].

2.1 Complaints and Anamnesis

Comments: the main complaints in HS include jaundice, changes in urine color (tea-colored, intensely yellow), and pallor of varying intensity depending on the severity of anemia; in severe cases, complaints of abdominal enlargement are reported [1-6]. The age of onset of complaints also varies from the first days of life to adulthood, depending on the severity of the disease [1-6]. All patients with suspected hereditary spherocytosis require a meticulous family history taking, including inquiries about family members (children or adults) with a similar condition and the age of onset of the first symptoms, in order to establish a timely diagnosis and assess the patient's condition [1-3,5,31].

In most cases, the first manifestations and consequently complaints appear in childhood and adolescence, but they may also occur in adulthood, even in the seventh to ninth decades of life, since HS is not always considered as a cause of gallstone formation and splenomegaly. Asymptomatic HS is detected (especially in childhood) following an aplastic crisis triggered by parvovirus B19 infection or influenza. Mild forms of HS may be identified during the screening of a patient's family members. Extremely severe variants of HS, accompanied by hydrops fetalis or stillbirth, develop in homozygous or compound heterozygous inheritance of severe vertical cytoskeleton protein defects.

When taking the medical history, it is necessary to determine whether there were any peculiarities in the neonatal period (intense and/or prolonged jaundice), whether close relatives and family members had episodes of jaundice of varying severity, cholelithiasis at a young age, episodes of profound hemoglobin drop during viral infections (influenza, parvovirus B19 infection), or any cases of stillbirth in the family [1-6].

2.2 Physical Examination

• All patients with suspected hereditary spherocytosis are recommended to undergo a physical examination in order to establish a timely diagnosis and assess the patient's condition [1-3,5,31].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: general inspection involves assessing the general physical status, height and weight, presence of secondary sexual characteristics appropriate for age, detection of congenital malformations, and abdominal palpation with measurement of the liver and spleen size (in centimeters below the costal margin). Typical clinical manifestations of HS include anemia, jaundice, and splenomegaly of varying severity [1-6].

• All patients with hereditary spherocytosis are recommended to undergo serial monitoring of spleen size during physical examination [1].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: enlargement of the spleen is accompanied by symptoms such as upper quadrant pain or early satiety, and manifestations of hypersplenism. Severe splenomegaly carries a risk of potential splenic rupture.

2.3 Laboratory Diagnostics

• All patients with suspected HS are recommended to undergo a complete blood count (CBC) with differential (using an automated hematology analyzer) and determination of blood reticulocyte count for differential diagnosis and confirmation of the diagnosis [1-6,31].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: patients with HS generally exhibit a normal mean corpuscular hemoglobin (MCH), a normal or less frequently decreased mean corpuscular volume (MCV), and an elevated mean corpuscular hemoglobin concentration (MCHC). Blood smears reveal microcytosis, hyperchromia, anisocytosis, poikilocytosis, and the presence of spherocytes. Howell-Jolly bodies and Cabot rings are found in erythrocytes following splenectomy. Reticulocytosis is invariably present in HS, with an absolute reticulocyte count (Ret) of 80 × 10⁹/L or more, and a ratio of reticulocyte count (Ret) to immature reticulocyte fraction (IRF) greater than 7.7 (Ret/IRF > 7.7) [15]. HS is classified as mild when Hb > 120 g/L and Ret/IRF > 19; moderately severe when Hb is 80–120 g/L, the relative microcyte count (micro-erythrocytes) (MicroR) > 3.5%, and the ratio of MicroR to the relative hypochromic erythrocyte count (Hypo-He) (MicroR/Hypo-He) > 2.5%; and severe when Hb < 80 g/L, MicroR > 3.5%, and MicroR/Hypo-He > 2.0%.

• All patients with suspected HS are recommended to undergo blood smear examination to analyze erythrocyte, platelet, and leukocyte morphological abnormalities (blood smear microscopy) with morphological evaluation of erythrocytes (mean erythrocyte diameter, sphericity index [normal > 3.5], ovalocytosis index [normal > 0.85], percentage of morphological erythrocyte forms) accompanied by Price-Jones curve construction [1-6,31].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

• All patients with suspected and diagnosed HS suggeted to undergo routine general biochemical blood testing (measurement of total bilirubin, free and conjugated bilirubin, lactate dehydrogenase [LDH] activity, aspartate aminotransferase [AST] activity, alanine aminotransferase [ALT] activity, and alkaline phosphatase [ALP] activity) to assess the intensity of hemolysis, diagnose cholestasis, and perform differential diagnosis of jaundice [1-6,31-34,38,39].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

• All patients with suspected HS are recommended to undergo an osmotic fragility test (OFT) of erythrocytes before and after incubation for differential diagnosis and confirmation of the diagnosis [1-6,31].

Comment: a normal OFT does not rule out the diagnosis of HS and may occur in 10–20% of HS cases. OFT may also be normal in the presence of iron deficiency, obstructive jaundice, or during the recovery phase following an aplastic crisis when the reticulocyte count is elevated. Cell dehydration occurring in spherocytes in HS can be one of the reasons for a normal OFT in patients with an unremoved spleen. Normal OFT values may be observed in patients with hereditary ovalocytosis and hemolysis or in patients with autoimmune hemolytic anemia.

GDR CLE 5Grade of recommendation C (level of evidence – 5)

• For all patients with suspected HS for the purpose of differential diagnosis and confirmation of the diagnosis, it is recommended to perform the EMA test (eosin-5-maleimide fluorescent dye test) [1-6,7-17,31].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comment: The EMA test is more informative for diagnosing HS, as it less frequently yields false-positive results. However, it is nonspecific and can detect erythrocytes with rare membrane disorders, such as band 3 protein abnormalities (e.g., congenital dyserythropoietic anemia type II (CDAII), Southeast Asian ovalocytosis (SAO)), changes in intracellular viscosity (e.g., sickle cells), and heat-sensitive monovalent cation transport (e.g., cryohydrocytosis). In mild or atypical cases, interpretation difficulties are likely to arise when the result falls between normal values and those typical for HS. Flow cytometric EMA test can help differentiate hereditary pyropoikilocytosis (HPP) with MCV < 60 fL and hereditary ovalocytosis from HS based on the classification of the fluorescence intensity reduction degree: for HPP (lowest) < HS < ovalocytosis < normal control. Although similar erythrocyte fluorescence values in HS are observed in other rare erythrocyte abnormalities – CDAII, SAO, and cryohydrocytosis – they can be distinguished based on their distinct clinical features (Appendix A3.3, A3.4). In some cases of warm autoimmune hemolytic anemia due to the binding of antibodies (IgG class) to extracellular fragments of band 3 protein, the EMA test may show reduced values. Other atypical cases of HS may yield abnormal histograms, which are identified by overlaying normal and control (typical HS) histograms. Normal fluorescence results are obtained in patients with reticulocytosis or cold agglutinin autoimmune hemolytic anemia.

As an additional test for diagnosing HS, red blood cell deformability (filtrability) testing is used [17]. Red blood cell filtrability testing has demonstrated high sensitivity as well as maximum specificity in the differential diagnosis of HS and other hemolytic anemias, primarily pyruvate kinase deficiency [17]. HS is characterized by red blood cell filtrability values of 0 – 0.31 units.

When choosing the necessary laboratory test for diagnosing a mild or atypical form of the disease, it is essential to consider the sensitivity and specificity of the test, the complexity of its implementation, and the total cost of the study. Since HS is associated with a structural defect in the red blood cell membrane cytoskeleton, the test results must determine whether the red blood cell defect is membrane-related or not.

Identification of the molecular genetic defect confirms the diagnosis of HS, but is not required for diagnosis in most cases, as an accurate diagnosis can be made based on red blood cell indices, clinical data, family history, and positive results of standard tests. However, it is necessary in cases where the patient's clinical condition does not correspond to the severity of HS present in other family members.

• For patients with HS dependent on red blood cell-containing blood component transfusions, it is recommended to study iron metabolism parameters (serum ferritin level, serum transferrin level, total iron-binding capacity (TIBC), serum iron level, and transferrin saturation (TSAT)) to diagnose secondary hemochromatosis [19-22].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

• For all patients with HS, it is recommended to confirm the diagnosis using molecular genetic methods (next-generation sequencing, NGS) [18].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comment: performing a molecular genetic study is crucial for verifying the diagnosis in cases of ambiguous laboratory test results, as well as in the following situations:

- the clinical phenotype is more severe than expected based on red blood cell morphology;

- red blood cell morphological features in a child do not correspond to a diagnosis of HS, provided that a parent has HS;

- the diagnosis remains unclear prior to splenectomy.

• For all patients with HS who develop an aplastic crisis, it is recommended to determine parvovirus B19 (Parvovirus B19) DNA in bone marrow aspirate by quantitative assay (A26.30.012.002) and/or to detect class M antibodies (IgM) to parvovirus B19 (Parvovirus B19) in the blood in order to diagnose parvovirus B19-associated pure red cell aplasia [1-2].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comment: in patients with HS, aplastic crises are caused by transient red cell aplasia (TRCA) resulting from parvovirus B19 infection (parvovirus B19 also causes erythema infectiosum, known as "fifth disease") [1,2]. Aplasia results from the direct cytotoxic effect of parvovirus B19 on erythroid precursors, and precursors of other cell lines may also be damaged to some extent. Patients may experience increasing headache, weakness, dyspnea, more severe anemia than usual, and a profound decrease in reticulocyte count (usually less than 1% or 10 × 10⁹/L). Fever, signs of upper respiratory tract infection, and/or gastrointestinal symptoms may also be present. Skin rashes lack specific characteristics. Reticulocytopenia appears around the 5th day of infection and lasts for 5-10 days. Worsening of anemia occurs shortly after reticulocytopenia, with Hb dropping to 39 g/L. The first sign of recovery from the infection is high reticulocytosis, which, while profound anemia persists, is sometimes mistakenly interpreted as hyperhemolysis syndrome. Recovery is typically accompanied by the appearance of a large number of normoblasts in the peripheral blood (more than 100 per 100 leukocytes). The diagnosis of TRCA is confirmed by elevated levels of IgM to parvovirus B19 in the blood. Recovery from parvovirus B19 infection leads to the appearance of a protective titer of IgG, preventing reinfection with this virus throughout the patient's life. No controlled trials on TRCA therapy have been conducted. Most patients recover spontaneously [1,2].

Although most adults have acquired immunity to parvovirus B19, hospital workers who are susceptible and in contact with TRCA patients are at high risk of nosocomial transmission of erythema infectiosum. Infection acquired during the second trimester of pregnancy can lead to fetal hydrops and stillbirth, therefore isolation precautions are necessary for pregnant staff members.

Table 2. Diagnostic criteria for HS.

2.4 Instrumental Diagnostics

• For patients with HS dependent on red blood cell-containing blood component transfusions who show laboratory evidence of tissue iron overload (serum ferritin > 1000 ng/mL), it is recommended to perform T2*-weighted magnetic resonance imaging (MRI) of the abdomen (liver) and heart for the timely diagnosis of secondary hemochromatosis [1,2,19-22].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

• For all patients with HS, it is recommended to perform a comprehensive ultrasound examination of the abdominal organs to assess the size of the liver and spleen, detect accessory spleens, and diagnose cholelithiasis [1,2].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

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

As with any chronic condition requiring lifelong medical interventions, patient well-being is influenced not only by technical aspects but also by the modalities of care delivery. Patient-centered care is one of the most critical factors, and medical organizations must pay special attention to minimizing the negative impact of medical care on patients' education, work, and family life, enabling them to lead as active and normal a lifestyle as possible.

3.1 Conservative Treatment

The goal of conservative treatment is to ensure normal growth and development of the child, as well as the prevention and timely treatment of complications of the underlying disease in adulthood [1,2,5].

• All patients with severe and moderate hereditary spherocytosis are recommended to take #folic acid** at a dose of 2–5 mg/day to prevent megaloblastic and aplastic crises [1,2,5].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: in patients not receiving #folic acid** supplementation who present with hemolysis, the development of an aplastic crisis is due to folate deficiency [1–5,7].

• For patients with hereditary spherocytosis, red blood cell transfusions are recommended when the hemoglobin concentration drops below 60 g/L [1,2,5].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: in severe hereditary spherocytosis in young children (under 3 years of age), monthly replacement transfusions of red blood cell components may be required; in this case, only leukodepleted, individually matched packed red blood cells should be used. Transfusion therapy with packed red blood cells must be accompanied by adequate chelation therapy [1,2,5].

• For patients with hereditary spherocytosis older than 2 years with laboratory evidence of tissue iron overload and/or organ iron overload according to T2* magnetic resonance imaging (MRI) it is recommended to prescribe deferasirox** [1,2,3,5,23–26].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: Deferasirox** dispersible tablets are prescribed at an initial dose of 20 mg/kg/day orally once daily, followed by titration in increments of 5 mg/kg/day up to a maximum dose of 40 mg/kg/day or a decrease depending on serum ferritin concentration. Deferasirox** film-coated tablets are prescribed at an initial dose of 14 mg/kg/day orally once daily, followed by titration in increments of 3.5 mg/kg/day depending on serum ferritin levels; the maximum dose is 28 mg/kg/day [20–23].

3.2 Surgical Treatment

• Patients with hereditary spherocytosis are recommended to undergo splenectomy to stop hemolysis and increase erythrocyte lifespan according to the following indications [1–3,5,27–29,31]:

- Severe hereditary spherocytosis at an age no earlier than 3 years;

- Moderate hereditary spherocytosis at the age of 6–12 years;

- Mild hereditary spherocytosis in the presence of gallstones with simultaneous splenectomy and cholecystectomy at any age older than 6 years; in the presence of high hyperbilirubinemia, reticulocytosis, and a normal hemoglobin concentration at an age older than 6 years (to prevent the development of cholelithiasis).

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: splenectomy is a very effective method when it is necessary to reduce hemolysis and increase red blood cell lifespan [1,2,27,28]. Clinical manifestations and the risk of complications (gallstones) are significantly reduced in severe hereditary spherocytosis and completely resolved in milder forms; however, the risk of life-threatening sepsis from encapsulated microorganisms, especially Streptococcus pneumoniae, increases. Recent data demonstrate that splenectomy in children with hereditary spherocytosis is fairly safe (short-term with no fatalities, rare complications reported).

The choice of splenectomy technique (endoscopic or open laparotomy) is made by the surgeon. The endoscopic method is preferred due to less pain, shorter hospital stay, and a good cosmetic effect [1,2,27–29,31].

3.3 Other Treatment

• Adult patients with hereditary spherocytosis are recommended standard thrombosis prophylaxis (B01AB – heparin and its derivatives, B01AC – platelet aggregation inhibitors, excluding heparin) during and after splenectomy [1,2,27,28].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: splenectomy is usually accompanied by an increase in platelet count, in some cases up to 1000 × 10⁹/L. There is insufficient data on the risk of thrombosis in pediatric patients to expand the indications for thrombosis prophylaxis during splenectomy [1,2,27,28]. An exception is made for patients with co-inherited thrombophilia.

• All patients with hereditary spherocytosis and concomitant cholelithiasis have an indication for cholecystectomy [1,2,7].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: liver and biliary tract dysfunction is one of the most frequent complications of hereditary spherocytosis [1–5,7]. Chronic hemolysis, with its accelerated bilirubin turnover, leads to cholestasis and a high incidence of cholelithiasis [1–5,7]. A marked increase in the unconjugated bilirubin fraction has been reported in association with a genetic defect in the glucuronosyltransferase system (Gilbert syndrome).

Common bile duct obstruction is often incomplete because pigment stones are small, but they can still cause characteristic biochemical changes of cholestasis. Biliary sludge is a viscous material that does not produce acoustic shadowing on ultrasound and can be a precursor to gallstone development.

It has been proven that removal of the spleen before gallstones appear completely prevents their future development [1,2,7]. A significant number of patients with hereditary spherocytosis develop cholelithiasis in the first decade of life. Patients with hereditary spherocytosis and co-inherited Gilbert syndrome have a high risk of developing cholelithiasis [2].

• All adult patients with hereditary spherocytosis who develop trophic ulcers are recommended to undergo splenectomy [1,2].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: when trophic ulcers develop in adult patients, adequate analgesia is necessary (drugs from the M01A group – non-steroidal anti-inflammatory and antirheumatic drugs, N02BE – anilides, specifically paracetamol** are used), along with regular cleansing of the ulcer surface with antiseptics, physical therapy to normalize venous outflow (specifically, intermittent pneumatic compression of the lower extremities can be used), and oral zinc sulfate at 200 mg 3 times a day [1,2]. Lower extremity trophic ulcers do not occur in children. The development of trophic ulcers has been described in adult patients with moderate or severe hereditary spherocytosis who have not undergone splenectomy. Trophic ulcers are typically bilateral and localized in the malleolar region. They can be either painless or accompanied by intense pain. The pathogenesis is not fully understood; most likely, they are a consequence of microcirculatory disturbance and low tissue oxygenation. A role for zinc deficiency in their development cannot be excluded. Local use of antibacterial agents (creams, gels, ointments, etc.) is discouraged because microorganisms on the wound surface very frequently develop resistance to them; systemic antibacterial therapy is prescribed when necessary. As empirical antibacterial therapy, systemic antimicrobial drugs active against Staphylococcus aureus and Streptococcus spp. are prescribed (J01D other beta-lactam antibacterial drugs, J01CF beta-lactamase-resistant penicillins, J01FF lincosamides).

4. Medical Rehabilitation and Sanatorium-Resort Treatment

No specific rehabilitation measures have been developed for patients with hereditary spherocytosis. Regardless of age and ongoing therapy, patients with hereditary spherocytosis can attend preschools and schools, stay in recreation camps, and engage in physical culture and sports (non-contact sports such as swimming, etc., in cases of significant splenomegaly, or without restriction in other cases).

Regardless of age, patients with hereditary spherocytosis may receive sanatorium-resort treatment to improve their quality of life and restore their condition in accordance with the principles of sanatorium-resort treatment for the patient's existing disease complications and the volume of treatment received.

5. Prevention and Dispensary Observation

• All patients with hereditary spherocytosis are recommended follow-up care including periodic examinations by a specialist (a pediatrician, a general practitioner, or, if the medical institution has the appropriate position, a local hematologist) [1–6,31].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: therapy is carried out on an outpatient basis over the long term. Patients and their family members must be thoroughly briefed on the nature of the disease, potential complications of the therapy, the need to maintain an adequate fluid intake regimen, and trained in personal hygiene rules. At each visit to the hematologist, it is necessary to assess general health, the child's physical development, spleen size, and exercise tolerance. A child with hereditary spherocytosis must be regularly monitored by a hematologist: mild and moderate forms once a year; severe form monthly. Continuous monitoring of complications in patients with hereditary spherocytosis is advisable in order to reduce disability and improve the patients' quality of life [1–6,31].

• All patients with hereditary spherocytosis under the age of 18 are recommended to undergo the following as part of their follow-up care [1–6,31]:

  ○ a complete (clinical) blood count with differential and determination of blood reticulocyte levels (once a year, or more frequently if indicated);

  ○ comprehensive abdominal ultrasound;

  ○ determination of serum folic acid level in the absence of #folic acid therapy **.

GDR CLE 5Grade of recommendation C (level of evidence – 5)

• For patients with HS over the age of 18 with moderate or severe disease, as well as patients with HS who have undergone splenectomy, it is recommended to perform the following as part of follow-up monitoring [1,2]:

  ○ comprehensive abdominal ultrasound for the diagnosis of cholelithiasis (once a year);

  ○ blood ferritin level test, transferrin saturation (TSAT) test once a year (in patients dependent on red blood cell transfusion).

GDR CLE 5Grade of recommendation C (level of evidence – 5)

• Vaccine prophylaxis is recommended for all patients with HS before elective splenectomy [2,30].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: prior to splenectomy, all patients must be fully vaccinated in accordance with the National Immunization Schedule, as well as against pneumococcal, meningococcal, and Haemophilus influenzae type b infections. Unvaccinated patients with HS are strictly contraindicated from undergoing splenectomy due to the unjustifiably high risk of life-threatening septic complications. Despite vaccine prophylaxis, the risk of sepsis after splenectomy persists for life and is higher the younger the age at which splenectomy is performed [30].

• Antibiotic prophylaxis is recommended for all children who underwent splenectomy under the age of 6; in some cases, it is justified for splenectomy at an older age and in adults. As part of antibiotic prophylaxis, systemic antimicrobial drugs from group J01C (beta-lactam antibacterials, penicillins) or J01FA (macrolides) are used [2,30].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: acute viral hepatitis in patients with HS has the same clinical manifestations as in the general population. The frequency of viral hepatitis B in patients with HS is significantly higher than in the general population due to transfusion therapy. Treatment is carried out in the same way as in the general population [1,2,7].

• Full vaccination in accordance with the National Immunization Schedule is recommended for all patients with HS and is performed when their general condition is stable [2,30].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: vaccination against pneumococcal, meningococcal, and Haemophilus influenzae infections is recommended to be carried out at least 2 weeks before or 2 weeks after splenectomy. In children under 2 years of age, 13-valent pneumococcal conjugate vaccine (PCV13) is used, followed by revaccination with 23-valent pneumococcal polysaccharide vaccine (PPV23); in children over 2 years of age, vaccination with PPV23 is recommended, followed by revaccination every 3 years (vaccination schedule for risk groups) up to 10 years of age, and every 5 years for those over 10 years of age and adults.

Conjugated meningococcal vaccine is administered to children starting from 9 months of age and to adults. In children aged 9 to 23 months, the vaccination course with conjugated meningococcal vaccine consists of 2 injections of one vaccine dose each with an interval of at least 3 months. Over 2 years of age, vaccination is administered once.

Vaccination against Haemophilus influenzae infection is administered once.

6. Organization of Medical Care

Indications for emergency hospitalization to a medical organization:

1) development of symptoms of HS decompensation;

2) need for emergency care for acute surgical pathology.

Indications for planned hospitalization in a medical organization:

1) dispensary examination, including at the initial diagnosis of severe or moderately severe HS;

2) hospitalization of a patient with HS to perform elective splenectomy, cholecystectomy;

3) administration of replacement transfusion therapy.

Indications for patient discharge from a medical organization:

1) regression of anemia decompensation symptoms, improvement of the patient's condition, completion of the examination.

7. Additional Information

In general, the prognosis for life in HS is quite favorable. Implementation of these clinical guidelines makes it possible to maintain the patient's full working capacity. Life expectancy is limited primarily by the development of complications from the therapy received.

The organization of therapeutic dietary nutrition for patients with hereditary spherocytosis during inpatient treatment in medical organizations is carried out in accordance with the orders of the Russian Ministry of Health dated August 5, 2003, No. 330 "On measures to improve therapeutic nutrition in healthcare institutions of the Russian Federation", dated June 21, 2013, No. 395n "On approval of therapeutic nutrition standards", and dated September 23, 2020, No. 1008n "On approval of the procedure for providing patients with therapeutic nutrition" (Appendix A3.2).

After confirmation of the diagnosis and selection of treatment tactics, the patient is transferred to the follow-up care of a hematologist at their place of residence. It is also necessary to consider the possibility of consulting the patient at one of the Federal Centers providing specialized care to patients with HS:

1. FSBI "National Medical Research Center for Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev" of the Russian Ministry of Health, Moscow, Samory Mashela St., 1, tel.: +7 (495) 287-65-70;

2. FSBI "National Medical Research Center for Hematology" of the Russian Ministry of Health, Moscow, Novozykovsky proezd, 4a, tel.: +7 (495) 612-45-51.

Patients and their family members must be thoroughly briefed on the nature of the disease, potential complications of the therapy, and trained in personal hygiene rules.

Indications for hospitalization in a medical organization:

1) Planned hospitalization in a day or 24-hour hospital for planned transfusion of leukodepleted (leukoreduced) red blood cell suspension based on individual matching.

2) Planned hospitalization in a 24-hour hospital for splenectomy.

3) Planned hospitalization in a day hospital for iron overload examination if outpatient examination is impossible (e.g., performing T2* MRI under general anesthesia).

Despite the fact that most HS therapy is carried out electively, there are conditions that require emergency hospitalization.

Indications for emergency hospitalization in a 24-hour hospital:

1) Heart failure, cardiac arrhythmias.

2) Sepsis – including post-splenectomy.

3) Venous thromboembolism.

4) Cholelithiasis.

5) Development of acute liver failure associated with cirrhosis, viral hepatitis.

Indications for patient discharge from a medical organization:

1) stabilization of the condition;

2) improvement of general well-being;

3) increase in blood total hemoglobin concentration to 115-125 g/L.

National Data Registry for Hereditary Hemolytic Anemias

In such diseases, the collection of systematic records of all patients is fundamental for planning, referral to a medical facility, provision of services, and monitoring. The National Data Registry for Hereditary Hemolytic Anemias provides an official platform for collecting all necessary data. It is constantly updated and improved, maximizing its value for the provision and audit of medical services. Every patient with HS should be informed about the National Data Registry for Hereditary Hemolytic Anemias and asked for consent to include their data in this registry, including data on adverse events and regular examination results. Timely entry of data from patients who have given their consent contributes to meeting many management and audit requirements.

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

Akhaladze Dmitry Guramovich – Doctor of Medical Sciences, Member of the Russian Society of Pediatric Oncologists and Hematologists, Member of the Russian Association of Pediatric Surgeons, Head of the Department of Thoracoabdominal Surgery, Institute of Pediatric Surgery and Oncology, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Ministry of Health of the Russian Federation, Moscow.

Kuzminova Zhanna Andreevna – Candidate of Medical Sciences, Member of the Russian Society of Pediatric Oncologists and Hematologists, Senior Researcher at the Department of Hematology Treatment Optimization, Institute of Hematology, Immunology and Cell Technologies, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Ministry of Health of the Russian Federation, Moscow.

Lugovskaya Svetlana Alekseevna – Doctor of Medical Sciences, Professor, Member of the Russian Association for Medical Laboratory Diagnostics, Professor at the Department of Laboratory Diagnostics, Russian Medical Academy of Continuous Professional Education of the Russian Ministry of Health.

Lukina Elena Alekseevna – Doctor of Medical Sciences, Professor, Member of the National Hematological Society, Member of the European Hematology Association, Member of the International Bioiron Society; Head of the Department of Orphan Diseases, National Medical Research Center for Hematology of the Ministry of Health of the Russian Federation, Moscow.

Plyasunova Svetlana Aleksandrovna – Candidate of Medical Sciences, Member of the Russian Association for Medical Laboratory Diagnostics, Head of the Clinical Diagnostic Laboratory, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Ministry of Health of the Russian Federation, Moscow.

Ponomarev Rodion Viktorovich – Candidate of Medical Sciences, Member of the National Hematological Society, Hematologist at the Department of Hematology and Chemotherapy of Orphan Diseases, National Medical Research Center for Hematology of the Ministry of Health of the Russian Federation, Moscow.

Smetanina Nataliya Sergeevna – Doctor of Medical Sciences, Professor, Member of the National Hematological Society, Member of the Russian Society of Pediatric Oncologists and Hematologists, Member of the European Hematology Association, Member of the International Bioiron Society; Deputy Director of the Institute of Hematology, Immunology and Cell Technologies, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Ministry of Health of the Russian Federation, Moscow.

Tsvetaeva Nina Valentinovna – Candidate of Medical Sciences, Hematologist at the Department of Hematology and Chemotherapy of Orphan Diseases, National Medical Research Center for Hematology of the Ministry of Health of the Russian Federation, Moscow.

Conflict of interest

All clinical guideline development group members declare no conflict of interest.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

1. Hematologists

2. Pediatricians

3. Internists

4. General practitioners (family physicians)

5. Pediatric surgeons

6. Surgeons

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

Table 2. Levels of Evidence (LE) rating scale for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitative interventions)

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

Appendix A3.1 Federal centers providing specialized care to patients with hereditary spherocytosis

1. Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Ministry of Health of Russia (Moscow), 1 Samory Mashela St., Moscow, tel.: +7 (495) 287-65-70.

2. FSBI "National Medical Research Center for Hematology" of the Russian Ministry of Health, Moscow, Novozykovsky proezd, 4a, tel.: +7 (495) 612-45-51.

Appendix A3.2 Medical Nutrition Therapy

Organization of therapeutic diet for patients with hereditary spherocytosis during inpatient treatment in medical organizations is carried out in accordance with the following documents:

1. Order of the Ministry of Health of the Russian Federation No. 330 dated August 5, 2003, "On measures to improve therapeutic nutrition in healthcare institutions of the Russian Federation".

2. Order of the Ministry of Health of the Russian Federation No. 395n dated June 21, 2013, "On approval of therapeutic nutrition standards".

3. Order of the Ministry of Health of the Russian Federation No. 1008n dated September 23, 2020, "On approval of the procedure for providing patients with therapeutic nutrition".

Appendix A3.3 Laboratory tests used in the diagnosis of HS and other erythrocyte membranopathies

ORC – osmotic resistance; HS – hereditary spherocytosis; AIHA – autoimmune hemolytic anemia; CDA – congenital dyserythropoietic anemia.

Appendix A3.4 Features of Southeast Asian ovalocytosis (SAO), congenital dyserythropoietic anemia type II (CDA II), and hereditary stomatocytosis and related disorders

Appendix B. Physician Action Algorithms

Appendix B1. Diagnosis of HS

Appendix B2. Treatment of HS

Appendix C. Patient Information

Hereditary spherocytosis (synonyms: hereditary hemolytic spherocytic anemia, Minkowski-Chauffard syndrome, Minkowski-Chauffard anemia) is a genetically determined disease resulting from a defect in one of the erythrocyte membrane proteins. The disease manifests with decreased hemoglobin, jaundice, and splenomegaly. With intensive red blood cell destruction, gallstones may develop as a complication of the disease, which may require surgical treatment. In severe cases accompanied by profound hemoglobin reduction, patients require red blood cell transfusions to maintain a blood hemoglobin concentration above 70 g/L. Splenectomy allows patients to maintain hemoglobin levels above 70 g/L, eliminating the need for red blood cell transfusions; however, such surgical treatment can only be performed after completing full routine vaccination according to the National Immunization Schedule, as well as additional vaccinations against meningococcal, pneumococcal, and Haemophilus influenzae type b infections at the patient's age over 3 years (optimally over 5 years), which significantly reduces the risk of life-threatening infections in the patient's future life.

1. All patients with HS must be regularly monitored by a hematologist:

- for mild and moderate forms: once a year;

- for severe form: once a month.

2. Additional folic acid supplementation is mandatory for all patients with HS;

3. Patients undergo periodic laboratory monitoring (indications and frequency of control tests are determined by the attending physician):

○ complete blood count (CBC) with differential, blood reticulocyte count;

○ serum folic acid level determination;

○ blood ferritin level test, transferrin saturation (TSAT) test.

4. Periodic ultrasound examination of the abdominal organs (comprehensive) is performed;

5. All patients with HS must be vaccinated in accordance with the National Immunization Schedule, as well as against pneumococcal, meningococcal, and Haemophilus influenzae type b infections;

6. Children are allowed to attend kindergartens, schools, and participate in extracurricular clubs and sections;

7. Dietary restrictions may be required if cholecystitis and cholelithiasis develop.

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

Not applicable.