Transfusing ABO‐compatible blood avoids most acute hemolytic reactions, but donor units that are ABO compatible are not necessarily ABO identical. Emerging data have raised concerns that ABO‐nonidentical blood products lead to adverse outcomes.
STUDY DESIGN AND METHODS
A large multihospital registry (Transfusion Registry for Utilization, Surveillance, and Tracking) was used to determine the association between exposure to ABO‐nonidentical blood and in‐hospital mortality. Cox regression analyses controlled for sex, age, hemoglobin, creatinine, and in‐hospital interventions and stratified by age of blood and admission year.
Data from 18,843 non–group O patients admitted between 2002 and 2011 and receiving at least 1 unit of blood were analyzed. Overall, group A patients had significantly increased risk of in‐hospital death upon receiving a nonidentical unit (RR , 1.79; 95% CI, 1.20‐2.67; p = 0.005). There was no evidence of increased risk for group B or AB patients. Similar results were seen when only patients with circulatory disorders were considered. When patients with an injury or poisoning diagnosis were excluded, the risk of in‐hospital death after receiving a non‐identical unit was significantly higher in group A patients and significantly lower in Group B patients.
Our study demonstrates an adverse effect of ABO‐nonidentical blood in a broad range of patients with group A blood, after adjustment for potential confounders. Further research in this area is required to study possible mechanisms. Increased mortality associated with exposure to nonidentical blood in these patients would have a substantial impact at the population level; it would challenge how blood suppliers manage inventory and recruit donors and how health care providers administer blood.