Transfusion of Stored Autologous Blood Alters Reactive Hyperemia and Circulating Nitrite Levels in Healthy Volunteers

Abstract

2327 Background: Transfusion of human blood stored for over 2 weeks is associated with increased mortality and morbidity. During storage, packed red blood cells (PRBC) progressively release hemoglobin, which avidly binds nitric oxide (NO). We hypothesized that the NO mediated hyperemic response following ischemia would be reduced after transfusion of PRBC stored for 40 days. Methods and results: We conducted a cross-over randomized interventional study, enrolling ten healthy adults. Nine volunteers completed the study. Each volunteer received one unit of 40-day and one of 3-day stored autologous leukoreduced PRBC, on different study days according to a randomization scheme. Blood withdrawal and reactive hyperemia index (RHI) measurements were performed before and 10 minutes, 1 hour, 2 hours, and 4 hours after transfusion. The RHI was lower (13% mean post-transfusion difference) after transfusion of 40-day as compared to 3-day stored PRBC (p=0.01). Plasma cell-free hemoglobin and bilirubin levels were higher after transfusion of 40-day than after 3-day stored PRBC (p=0.02 and 0.001, respectively). Plasma levels of potassium, LDH, haptoglobin, cytokines, as well as blood pressure, did not differ between the two transfusions and remained within the normal range. Plasma nitrite concentrations increased after transfusion of 40-day stored PRBC, but not after transfusion of 3-day stored PRBC (p=0.01). Conclusions: Transfusion of autologous PRBC stored for 40 days is associated with increased hemolysis and reduced RHI, possibly due to enhanced NO scavenging by cell-free oxyhemoglobin. Disclosures: Bloch: Massachusetts General Hospital: Patents & Royalties, The Massachusetts General Hospital has filed patents related to the use of small molecule inhibitors of BMP signaling to modulate iron metabolism, and PBY, RTP and KDB may be eligible to receive royalties. Yu:Massachusetts General Hospital: Patents & Royalties. Zapol:Dr. Warren Zapol receives royalties from patents on inhaled nitric oxide licensed by Massachusetts General Hospital to Linde Corp, Munich, Germany, and Ikaria Corp, Clinton, New Jersey. Dr. Zapol has applied for patents on inhaled nitric oxide and blood t: Patents & Royalties.