Role of the spleen and effect of splenectomy in sickle cell disease.

HE DIFFERENTIAL AGGLUTINATION METHOD’ of determining I the life-span of the erythrocyte has been applied to the study of sickle cell anemia,2’3 sickle-cell/Hb-C disease46 and pure ( homozygous ) hemoglobin-C disease.7’8 In this way the survival time of sickle cells was found to be shortened whether transfused to normal recipients, to recipients with sickle cell trait. or to recipients with sickle cell anemia, whereas normal and sickle cell trait cells exhibited normal survival times when transfused to recipients with sickle cell anemia. Singer9 concluded from these cross-determination studies that the shortened survival time of sickle cells was due essentially to the removal from the circulating blood of cells which were abnormal by reason of an intracorpuscular defect. The findings in sickle-cell/Hb-C disease and in pure hemoglobin-C disease were of a like nature. The Ashby method1 permits determination of the survival time of erythrocytes transfused to recipients of suitable blood group, whereas the labeling of erythrocytes with radioactive isotopes permits determination of the survival time of erythrocytes within their peculiar blood stream. Weinstein et al.1#{176} determined the survival time in their parent circulations of the erythrocytes of patients suffering a variety of abnormal hemoglobin syndromes by the use of radioactive sodium chromate, and found for this method good agreement with the survival times suggested from crossdetermination studies by the Ashby method. By the N15-glycine method of labeling erythrocytes in vivo, the half-life time of sickle cells has been cornputed in one instance to be 29 days,” and in another, 11 days.’2 James and Abbott’2 suggested that this difference in the survival times of sickle cells, containing only “5” type hemoglobin (together with a small amount of fetal hemoglobin), might be attributed to the influence of extracorpuscular factors, but recognized that no substantial evidence for the presence of such factors had been reported. It should be taken into account, however, that whereas the sickle cells were stated to contain 100 per cent “S” type hemoglobin in the case of James and Abbott, this was not determined in the case of London et al.1’ Cr51-labeling also permits the simultaneous determination of the survival times of abnormal cells in the donor’s own circulation and in that