Selective isolation of young erythrocytes for transfusion support of thalassemia major patients.

Transfusion-induced hemochromatosis remains a major therapeutic complication in the management of thalassemia major patients. Using available blood cell component separators, a system has been devised to selectively harvest young red cells from transfusion support of these subjects. Red cell units isolated by this method have an average estimated mean cell age of 30 days, compared to 60 days for unfractionated blood, and contain 80% of the hemoglobin content of standard red cell units. Radiochromium half-life for young cells measured in 7 asplenic thalassemia major patients averaged 47.4 days compared to 29.5 days for routine frozen red cells. The enhanced survival is not due to reticulocyte enrichment alone, but represents a true cohort of younger red cells. Although costly, this modality could theoretically halve the transfusion requirement in transfusion-dependent patients. When combined with modern iron chelator regimens, it may be possible to achieve consistently negative iron balance prior to the onset of hemochromatosis.