Prevalence of HLA sensitization in female apheresis donors.

Abstract

Transfusion-related acute lung injury (TRALI) is a serious complication of plasma-containing blood components. Studies have implicated HLA antibodies along with biologically active lipids in stored blood in the pathogenesis of TRALI. It has been proposed that the exclusion of HLA-untested, multiparous donors of plasma-rich components, including plasma and single-donor apheresis platelets, would substantially reduce the risk of TRALI. To investigate the feasibility of such an exclusion, 332 female plateletpheresis donors with a record of over 9000 donations, none of which were associated with TRALI, were studied. Seventeen percent of female donors demonstrated HLA sensitization. Parity and HLA sensitization were significantly correlated (p<0.0001), with sensitized donors having an average of 2.9 (+/- 0.6 95% CI) prior pregnancies and unsensitized donors having an average of 1.8 (+/- 0.2 95% CI) prior pregnancies. The percentage of HLA-sensitized women with 0, 1 to 2, and > or = 3 pregnancies was 7.8, 14.6, and 26.3, respectively. These findings confirm the hypothesis that multiparous women (> or = 3 pregnancies) represent an increased potential risk for TRALI. However, the exclusion of multiparous plateletpheresis donors would eliminate one-third of our female donor pool. Screening such donors for HLA sensitization may represent the optimal approach for identifying donors at risk for causing TRALI, but this still would result in the deferral of 8 percent of female plateletpheresis donors. At present, prospective screening to identify donors at risk for causing TRALI is not justified.