STUDIES ON CONGENITAL HEMOLYTIC SYNDROMES

Rates of destruction of erythrocytes and of effective production of erythrocytes and hemoglobin have been determined in eight patients with sickle cell anemia. The method employed was based upon survival of chromium-labeled erythrocytes in patients in whom a state of hemopoietic equilibrium was present. Rates of destruction and production of erythrocytes tended to be greater than in patients with homozygous thalassemia and congenital spherocytosis. Comparison of data from patients with the same three congenital hemolytic disorders has indicated that peripheral indexes such as concentration of hemoglobin and hematocrit do not accurately reflect the true comparative degrees of anemia in terms of total volume of erythrocytes. Plasma volume was markedly expanded in patients with sickle cell anemia and very little, if at all, in congenital spherocytosis. Intermediate values were found in patients with thalassemia. Two patients with sickle cell anemia in whom the spleen was enlarged demonstrated splenic sequestration of erythrocytes. The role of the spleen in this disease has been discussed. Hepatic sequestration of erythrocytes was demonstrated in all eight patients to a significantly greater degree than in patients with other congenital hemolytic disorders. Results of studies of erythrocyte survival in one patient when well and when in crisis indicated that hyperhemolysis was not a significant feature of the painful crisis. Contraction of plasma volume during a painful crisis of sickle cell anemia has been described. Studies in patients with sickle cell-thalassemia and sickle cell-hemoglobin C disease demonstrated that the hemolytic defects were less severe than in the usual patient with sickle cell anemia.