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.