Hereditary spherocytosis (HS) is a form of hereditary hemolytic anemia common in Northern Europe and is inherited in an autosomal dominant pattern due to alterations of a gene on chromosome 8, in which about a quarter of the cases are clinically normal at diagnosis and of which sporadic cases due to new mutations are described. The disease is due to defects in the expression of erythrocyte membrane proteins that cause structural changes. The mechanism of sphericization in spherocytosis is caused by a spectrin deficiency, either primary or secondary to an ankyrin deficiency. This results in reduced cytoskeleton density, failure of the cytoskeleton to bind to band 3 (structural membrane protein), and subsequent instability of the lipid bilayer. Thus, lipid loss in the form of vesicles is observed both in vitro and in vivo. A simi lar effect is caused by the reduction of band 3. Further causes of spherocytosis are due to protein 4.2 deficiency, in which altered binding of spectrin via ankyrin and band 3 to the membrane protein CD47 is observed, and defective spectrin- binding protein 4.1. The various defects cause alterations in membrane properties that are reflected in erythrocyte metabolism (Table 1). Increased erythrocyte fragility is directly related to spectrin deficiency, which can range from 30 to 80% of normal, and the severity of hemolysis. The chronic hemolysis that usually accompanies spherocytosis requires splenectomy in the most serious cases. The efficacy of the treatment appears to be related to the extent of spectrin deficiency so that with a deficiency >70%, a practically complete reduction of chronic hemolysis is usually observed. The laboratory data characteristics of hereditary spherocytosis are shown in Table 2. The diagnosis and judgment of the severity of hereditary spherocytosis are based on the integration of clinical and laboratory data. Sometimes anamnestic and family reports, as well as splenectomy, are useful (Table 15.17). A consistent presence of spherocytes is not always detectable; indeed sometimes, they are scarce and therefore do not represent a safe indicator. In addition, there are other conditions that can cause spherocyte formation, such as immunohemolytic anemias, certain enzymatic deficits of the erythrocyte and trauma. Although not very sensitive, an increase in self-hemolysis and its correction with glucose and ATP are indices with good diagnostic value. To have diagnostic certainty, it is necessary to analyze the mem brane protein content by separation procedures (SDS-PAGE electrophoresis, HPLC+MS). An alternative procedure is f low cytometry of intact red blood cells labeled with eosin- 5′-maleimide, which binds to band 3.

Table1. Erythrocyte abnormalities inherent in hereditary spherocytosis

Table2. Tests and laboratory data in pre and postsplenectomy hereditary spherocytosis

Table3. Severity classification of hereditary spherocytosis

Rare forms of morphological abnormalities are represented by hereditary elliptocytosis and ovalocytosis. These are a heterogeneous group of conditions in which the suggested, but not exclusive, diagnostic criterion is the presence of at least 25% abnormal (elliptical/oval) erythrocytes under the microscope. These forms are also due to genetic mutations affecting the expression of membrane cytoskeleton proteins.

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اخبار العتبة العباسية المقدسة

يجسد قيم النهضة الحسينية.. قسم الشؤون الفكرية يصدر العدد 120 من مجلة (حيدرة) الثقافية

ضمن حملة الكفيل العتبة العباسية المقدسة تحيي مراسم ليلة الحادي عشر من المحرم في سامراء

المجمع العلمي يحيي عاشوراء بخدمة الزائرين وإقامة مجالس العزاء ببغداد والحمزة الشرقي

المؤمنون يحيون ليلة الحادي عشر من المحرّم عند مرقدي الإمام الحسين وأخيه العباس (عليهما السلام)

المزيد

الآخبار الصحية

تناول الجبن.. مفيد للجسم أم خطر يهدد صحتك؟

طبيبة أسنان تحذر.. لا تتجاهل هذه العلامة بعد التنظيف

يجب أن تأكل المزيد من الشمام هذا الصيف.. إليك السبب ؟

تأثير صحي كبير.. كم بيضة يجب أن تتناول يوميا؟

المزيد

الآخبار التكنلوجية

أداء خلايا البيروفسكايت الشمسية تحت الماء قد يزيد كفاءة تحويل الكهرباء

مسافة الأمان: أساس القيادة الآمنة وتجنب الحوادث

هل القيادة السريعة تعني استهلاك اكثر للوقود؟

لماذا يعتبر كوكب المريخ غير صالح للحياة؟

المزيد

مواضيع ذات صلة

C-Reactive Protein Rapid Latex Agglutination Test

Hyporegenerative Macrocytic Anemias/ Megaloblastic Anemias

Unstable Hemoglobins

Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency

Magnesium

lyme disease test

luteinizing hormone (LH assay, Lutropin) and follicle stimulating hormone (FSH) assay

liquid biopsy (Fluid biopsy, Fluid phase biopsy)

lipoproteins (High-density lipoproteins [HDLs, HDL-C], Low density lipoproteins [LDLs, LDL-C], Very-low-density lipoproteins [VLDLs], Lipoprotein electrophoresis, Lipoprotein phenotyping, Lipid fractionation, Non-HDL cholesterol, Lipid profile)

lipoprotein-associated phospholipase A2 (Lp-PLA2 PLAC test)

Hemolytic Anemias

Sickle Cell Anemia (Hemoglobinopathy S, Sickle Cell Disease)