Female donors and transfusion-related acute lung injury: A case-referent study from the International TRALI Unisex Research Group.

BACKGROUND Although quantitative evidence is lacking, it is generally believed that the majority of cases of transfusion-related acute lung injury (TRALI) are caused by female blood donors. We aimed to examine the relation between female donors and the occurrence of TRALI. STUDY DESIGN AND METHODS We performed an international, multicenter case-referent study. TRALI patients who were diagnosed clinically, independent of serology or donor sex, and had received transfusions either only from male donors or only from female donors (unisex cases) were selected. The observed sex distribution among the donors of these TRALI patients was compared to the expected sex distribution, based on the relevant donor populations. RESULTS Eighty-three clinical TRALI cases were included; 67 cases received only red blood cells (RBCs), 13 only plasma-rich products, and three both. Among RBC recipients the relative risk (RR) of TRALI after a transfusion from a female donor was 1.2 (95% confidence interval [CI], 0.69-2.1) and among plasma-rich product recipients the RR was 19 (95% CI, 1.9-191). The p value for the difference between RBCs and plasma was 0.023. CONCLUSION Our data support the notion that plasma from female donors is associated with an increased risk of TRALI, while RBCs from female donors are not.