The prevalence of leucocyte alloantibodies in blood donors from South China.

Background: Several studies had demonstrated that leucocyte antibodies including anti-human leucocyte antigen (anti-HLA) antibodies (class I and class II) and anti-human neutrophil antigen (anti-HNA) antibodies (HNA-1, -2 and -3) present in the blood products are responsible for transfusion-related acute lung injury (TRALI). Therefore, selection of blood products exclusive of anti-HLA and anti-HNA antibodies may lower the risk of TRALI reaction. However, the prevalence of leucocyte antibodies among blood donors in China is currently not known.

Study Design And Methods: Blood samples were collected from 454 male and 560 female donors (143 nulliparous and 417 multiparous female). HLA class I and II antibodies were analyzed by bead assays. Anti-HNA-1 and -2 antibodies were screened by the LABScreen assay (One Lambda Inc.), and HNA-3 were detected by antigen capture assay, and confirmed by the granulocyte agglutination test (GAT).

Results: Screening of the total cohort showed higher prevalence of HLA antibodies in female compared with male donors (19.64 vs. 4.63%). We found antibodies against HLA class I (13.21%) and HLA class II (11.43%) in 560 female donors. The most frequent antibodies against HLA class I and II in parous females (n = 69) reacted with were A*11 (28.81%), B*07 (42.37%), Cw*07 (20.34%) and DRB1*04 (40.43%) molecules. Among 778 donors (randomly selected from 1014 donors), we found three donors with neutrophil reactive antibodies, two against HNA-2 and one without known specificity. Anti-HNA-3 antibodies were not found so far.

Conclusion: In this study, we found alloimmunization against HLA class I, II and HNA in 4.63, 24.70 and 0.39%, respectively, in our female blood donors, indicating that the use of plasma containing blood products from parous female blood donors without HLA antibodies pre-testing may increase the risk of TRALI reaction. Although immunization against HNA seems to be a rare event in China, further observation is necessary to decide the necessity of HNA antibodies screening in our blood donors.