Hemolytic Poikilocytic Anemia Due To Reduced Ankyrin Binding Sites

Agre et al. (1981) presented evidence for reduction in the number of high affinity ankyrin binding sites. The findings were consistent with an abnormal organization of band 3 (109270) in the membrane. (Agre (1986) concluded that this change was probably a secondary one.) The patients showed chronic hemolytic anemia with very fragile microcytic red cells that had a great variety of shapes. Spectrin binding was normal and patients' ankyrin and spectrin (both radioiodinated) competed normally for the binding sites on normal red cell membranes. None of the individual components appeared to have abnormal thermal sensitivity. Inside-out vesicles from patients bound less radioiodinated ankyrin by about 50% than did control vesicles. One family was black and had an affected male with affected sister and brother and healthy parents who had normal red cell morphology. (Mistaken paternity was not revealed by genetic marker studies.) The proband, aged 23, had first required blood transfusion at age 5 years. Splenectomy at age 18 restored him to health. The affected sister, younger than the proband, underwent splenectomy and cholecystectomy with clinical improvement. The other affected sib had abnormal cell morphology but compensated hemolysis. The second family was white. The proband had splenectomy at age 51 years, following which she enjoyed good health. Her son had uniformly elliptocytic red cells but no anemia. Two other children had normal red cells.