Transfusion begets anemia: The effect of aged blood on hematopoiesis

BACKGROUND: Following trauma, transfusion of aged stored blood is often necessary yet associated with increased morbidity and mortality. Despite blood replacement, many patients have a prolonged anemia requiring further transfusions. The effects of aged blood on bone marrow (BM) hematopoiesis have not been studied, and we hypothesized that stored blood suppresses BM function. METHODS: Blood from Sprague-Dawley rats was stored for 1, 14, or 28 days with the industry preservative citrate-phosphate-dextrose-adenine-1 (CPDA-1). For in vitro studies, 5% supernatant was incubated with normal rat BM and cultured for erythroid (CFU-E) and granulocytemacrophage (CFU-GM) colony-forming units. Datawere compared with cultures of BMalone, 5% control plasma (negative control), and 12%CPDA-1. For in vivo studies, ratswere transfused with stored supernatants (5%estimated blood volume (EBV) over 30minutes). BM from each recipient was cultured for CFU-E and CFU-GM at 3 hours after transfusion. Data were compared with cultures of BM alone. Difference between groups determined by analysis of variance and Tukey's multiple comparison test. RESULTS: In vitro exposure to CPDA-1, control plasma, or 1-day supernatant (D1) had no effect on BM growth compared with BM alone. In vitro exposure to 14-day (D14) and 28-day (D28) supernatant significantly suppressed CFU-E by 60% and CFU-GMgrowth by 71% (both p < 0.05) comparedwithD1 ormedial alone.Therewere no differences betweenD14 andD28. Invivo exposure toD14 reducedBMCFU-Eand CFU-GM growth by 55% (both p < 0.05) compared with D1 supernatant. CONCLUSION: Plasma from aged blood adversely affects CFU-E and CFU-GMgrowth in rats. The effect is notmediated by CPDA-1. Transfusion of aged stored bloodmay contribute toBMdysfunction in critically ill patients, resulting in persistent anemia and the need for further transfusion. This BMdysfunction may also partly explain the observed increased susceptibility to infection.