Photo by Elise Amendola
A large study has revealed an unexpected association between blood donor characteristics and transfusion recipients’ outcomes.
It is the first study to suggest that red blood cell (RBC) transfusions from younger donors or female donors may increase the risk of death in recipients.
“We need further research to confirm these findings and to look at possible biological mechanisms,” said Michaël Chassé, MD, PhD, of Université Laval in Quebec, Canada.
“One possibility is that components in the blood of younger donors or female donors may affect the immune system of the transfusion recipient.”
For this study, Dr Chassé and his colleagues linked 30,503 patients who received a transfusion at The Ottawa Hospital between October 2006 and December 2013 with their respective blood donors (80,755 donors in total).
The average age of the recipients was 66.2 years. They were followed for an average of 2.3 years, with a maximum follow-up time of 7.2 years.
The researchers found that recipients of RBCs from female donors had an 8% increased risk of death from any cause per unit transfused, when compared with recipients of RBCs from male donors. The adjusted hazard ratio (aHR) was 1.08 (95% CI, 1.06-1.09; P<0.001).
A similar increased risk of death was observed for recipients of RBCs from younger donors. When compared to recipients of RBCs from donors ages 40 to 49.9, the risk of death was higher for recipients of RBCs from donors ages 17 to 19.9 (aHR=1.08; 95% CI, 1.06-1.10; P<0.001) and recipients of RBCs from donors ages 20 to 29.9 (aHR=1.06; 95% CI, 1.04-1.09; P<0.001).
“Though our research suggests that we should investigate what’s behind the associations that we found, there is no definitive evidence yet that proves that one type of blood is better or worse for patients,” said Jason Acker, PhD, of Canadian Blood Services in Edmonton, Alberta.
“This study opens up new areas of investigation where we can really dig into the biological explanations and understand true cause and effect.”
The study was published in JAMA Internal Medicine.
