Antibodies to A19 and Bw35 complexes of human leukocyte antigens are present in infertile subjects with sperm antibodies.

Sera and secretions from 100 couples with unexplained infertility were tested for sperm antibodies by cytotoxicity and passive hemagglutination and also for antibodies to human leukocyte antigen (HLA) by cytotoxicity assays. Lymphocytes of the study subjects were typed for 61 HLA-A and B alleles. Thirteen of 30 (43%) men with sperm autoimmunity also had HLA antibodies in their serum and/or seminal plasma samples, in contrast to 2 of 35 (6%) nonautoimmune males (P = 0.0003). Twenty-five of 35 (71%) sperm antibody-positive infertile women had HLA antibodies in their sera and/or secretions, while only 7 of 31 (23%) women without sperm antibodies were positive (P = 0.00007). Antibodies to HLA-A19 (A26, A29, AW30, AW31, AW32, AW33, and AW34) and Bw35 (B5, B15, B17, and B18) complexes were present in 19 of 22 (86%) infertile men and 44 of 48 (92%) infertile women positive for HLA antibodies (P less than 0.01). The presence of antibodies to HLA-A19 and/or Bw35 in the infertile subjects did not correlate with the presence of HLA-A19 and/or Bw35 in the husbands. The presence of antibodies to HLA-A19 and/or Bw35 in the cervical mucus of the infertile women correlated with their presence in the seminal plasma of their husbands. It is suggested that antibodies to sperm antigens cross-reactive with HLA-A19 and/or Bw35 may be relevant to infertility.