Ex vivo selective isolation of young red blood cells using the IBM-2991 cell washer.

Transfusion-induced hemochromatosis is a major complication in the therapy of severe chronic anemia. Improvement of transfused cell survival with a reduction in transfusion frequency is one possible approach to this problem. Using continuous-flow centrifugation (CFC), young red blood cells (YRBC) with enhanced in vivo survival have been isolated, but the expense and donor time required with this technique prohibit its widespread use for patient support. We studied the use of the IBM 2991 cell washer (CW) to isolate YRBC ex vivo from previously collected donor blood. Age-dependent red cell separation could be achieved using this instrumentation. Autologous mean red cell half-life (RBC-T50) (n = 9) for the younger cell fractions was 43.9 +/- 7.8 days compared to 34.7 +/- 5.8 days for the older cell fractions (n = 6, p less than 0.05). Paired measurement of RBC-T50 for young and old fractions in three donors showed an average survival increase of 41% for the YRBC. Adequate quantities of YRBC with enhanced survival can be obtained with less cost and less donor stress using the CW system compared to CFC. This approach could improve the management of patients with chronic transfusion requirements and merits further examination.