Prevalence of HLA sensitization in female apheresis donors

BACKGROUND: Transfusion-related acute lung injury (TRALI) is a serious comp lication of plasma-containing blood components. Studies have implicated HLA antibodies along with biologically active lipids in stored blood in the pa thogenesis of TRALI. It has been proposed that the exclusion of HLA-unteste d, multiparous donors of plasma-rich components, including plasma and singl e-donor apheresis platelets, would substantially reduce the risk of TRALI. STUDY DESIGN AND METHODS: To investigate the feasibility of such an exclusi on, 332 female plateletpheresis donors with a record of over 9000 donations , none of which were associated with TRALI, were studied. RESULTS: Seventeen percent of female donors demonstrated HLA sensitization. Parity and HLA sensitization were significantly correlated (p<0.0001), wit h sensitized donors having an average of 2.9 (+/- 0.6 95% CI) prior pregnan cies and unsensitized donors having an average of 1.8 (+/- 0.2 95% CI) prio r pregnancies. The percentage of HLA-sensitized women with 0, 1 to 2, and g reater than or equal to 3 pregnancies was 7.8, 14.6, and 26.3, respectively . CONCLUSION:These findings confirm the hypothesis that multiparous women (gr eater than or equal to 3 pregnancies) represent an increased potential risk for TRALI. However, the exclusion of multiparous ptateletpheresis donors w ould eliminate one-third of our female donor pool. Screening such donors fo r HLA sensitization may represent the optimal approach for identifying dono rs at risk for causing TRALI, but this still would result in the deferral o f 8 percent of female plateletpheresis donors, at present, prospective scre ening to identify donors at risk for causing TRALI is not justified.