Abstract

BACKGROUND Fresh red cells may improve outcomes in critically ill patients by enhancing oxygen delivery while minimizing the risks of toxic effects from cellular changes and the accumulation of bioactive materials in blood components during prolonged storage. METHODS In this multicenter, randomized, blinded trial, we assigned critically ill adults to receive either red cells that had been stored for less than 8 days or standard-issue red cells (the oldest compatible units available in the blood bank). The primary outcome measure was 90-day mortality. RESULTS Between March 2009 and May 2014, at 64 centers in Canada and Europe, 1211 patients were assigned to receive fresh red cells (fresh-blood group) and 1219 patients were assigned to receive standard-issue red cells (standard-blood group). Red cells were stored a mean (+/-SD) of 6.1+/-4.9 days in the fresh-blood group as compared with 22.0+/-8.4 days in the standard-blood group (P<0.001). At 90 days, 448 patients (37.0%) in the fresh-blood group and 430 patients (35.3%) in the standard-blood group had died (absolute risk difference, 1.7 percentage points; 95% confidence interval [CI], -2.1 to 5.5). In the survival analysis, the hazard ratio for death in the fresh-blood group, as compared with the standard-blood group, was 1.1 (95% CI, 0.9 to 1.2; P=0.38). There were no significant between-group differences in any of the secondary outcomes (major illnesses; duration of respiratory, hemodynamic, or renal support; length of stay in the hospital; and transfusion reactions) or in the subgroup analyses. CONCLUSIONS Transfusion of fresh red cells, as compared with standard-issue red cells, did not decrease the 90-day mortality among critically ill adults. (Funded by the Canadian Institutes of Health Research and others; Current Controlled Trials number, ISRCTN44878718.).

Abstract

BACKGROUND WBC reduction of all blood components is being introduced in many countries. Prevention of immunologic side effects of transfusions is part of the motivation. To compare the immunogenicity of before- or after-storage WBC-reduced RBCs with RBCs without buffy coat, a randomized clinical trial was performed. STUDY DESIGN AND METHODS Cardiac surgery patients were randomly assigned to receive either RBCs without buffy coat (PCs), WBC-reduced RBCs that were filtered before storage (FFs), or WBC-reduced RBCs that were filtered after storage (SFs). Serum samples for antibody analyses were collected before and after surgery. RESULTS Sera of 404 patients were tested. Of the 317 patients with negative preoperative screening, 12. 6 percent developed anti-WBC antibodies (PC, 14. 5%; FF, 9. 6%; SF, 13. 3%). Of the 87 patients with preoperative anti-WBC antibodies, 28. 7 percent showed a marked increase in panel reactivity (PC, 31. 3%; FF, 29. 0%; SF, 25. 0%). ELISA showed the newly formed antibodies to be of IgG class and directed against HLA class I in more than 90 percent of the samples tested. Newly formed anti-RBC antibodies appeared in 5. 3 percent (PC, 7. 1%; FF, 3. 4%; SF 5. 4%). Alloimmunization against WBCs and RBCs was strongly correlated (p < 0. 01). The differences in newly formed anti-WBC antibodies and anti-RBC antibodies between the trial arms did not show significance. CONCLUSION Buffy coat removal, and additional WBC reduction by filtration, either before or after storage, result in similar posttransfusion alloimmunization frequencies after a single transfusion event with multiple RBCs.