Abstract:
Spherocytosis is a common autosomal-dominant inherited disease, in which the erythrocytes are spherical due to the heterogeneous defects of various membrane proteins. The erythrocytes are also osmotically more fragile. Spherocytosis is one of the hemolytic anemias. The clinical picture ranges from very mild to extremely severe forms.
Clinical picture:
The premature destruction of erythrocytes caused by fragility, known as hemolysis, occurs in the spleen which becomes enlarged. By increasing erythropoiesis, the hematocrit can more or less be maintained normal. Certain infections, especially parvovirus B19, can cause suppression of erythropoiesis. This usually goes unnoticed in patients with normal erythrocytes. However, in patients with hemolytic anemias such as spherocytosis, this can lead to a dramatic decrease of the hematocrit. This phenomenon is called "aplastic crisis" and normally lasts 7-10 days. Patients often have bilirubin gallstones and cholecystitis due increased amounts of bilirubin.
The diagnosis is successfully established based on the clinical picture, the typical blood film and the increased osmotic fragility of red blood cells. Therapy for spherocytosis consists of splenectomy. The spherocytes' life span clearly increases as a result, however, it does not normalize completely.
Hematology:
The erythrocytes are round, without central pallor and up to 20-25% are microspherocytes. Hemoglobin concentration is normal to slightly decreased. Reticulocytes are increased to over 8%. The MCV is normal to increased, the MCH is normal and the MCHC is increased. The latter occurs only in spherocytosis.
Bone marrow:
Increased erythropoiesis is present in the bone marrow. Bi-nucleated pronormoblasts and normoblasts can occur.