ACCELERATED HEMOLYSIS IN Hb M AKITA DISEASE
In Hb M Akita disease, in addition to livid cyanosis which is peculiar to this hemoglobinopathy, signs reminiscent of accelerated hemolysis, such as increased serum hemobilirubin (1.4 mg/dl), splenomegaly (2 finger breadths), anemia (Hb=10.7 g/dl) and a rise in reticulocyte index (2.7) were observed. The anemia was thought to be in part due to shortened life span of red cells (51Cr-tagging method T 1/2=11.5 days) and the sequesteration of red cells in the spleen (the spleen: liver ratio of 51Cr surface count=2.5-3.0), but its main feature was sought for in an ineffective erythropoiesis of the bone marrow induced by intracellular degeneration of unstable Hb M Akita (β92 His → Tyr) and its modified pigment (Hb Akita) on the way of their production in nucleated red cells. In spite of the presence of markedly increased hematopoiesis (8 times as large as the normal; M:E ratio=0.22:1.00) deficiency of red cell supply from the bone marrow to the peripheral blood was evident (59Fe red cell utilization =40.5 per cent). The distribution of the hematopoietic sites throughout the whole body was reasonably uniform. The intraerythrocytic enzyme (glycolytic system) level was rather increased, being suggestive of protective reaction in response to intraerythrocytic degradation of hemoglobin.
