Relationship between unexplained infertility and human leukocyte antigens and expression of circulating autogeneic and allogeneic antisperm antibodies.

PURPOSE: The association between unexplained infertility, human leukocyte antigens (HLA) and expression of circulating antisperm antibodies was studied in 52 couples with unexplained infertility and 15 infertile and 9 fertile couples. METHODOLOGY: Evaluation parameters included Terasaki's HLA microlymphocytotoxicity test, circulating antisperm antibodies using immunofluorescence technique. RESULTS: Fifty-two couples (8.7%) out of 600 consecutive clinic attendants had unexplained infertility. Unexplained infertility was associated with circulating antisperm antibodies (22 versus 13 and 0% for men and 18.5 versus 13 and 0% for women). HLA class 1 B6 and B52 and Cw7 and HLA class 2 DR4 and DR6 and sharing of HLA B6, DR4 and DR6 were found more in couples with unexplained infertility. Combined expression of antisperm antibodies by couples, demonstrated more homozygosity for HLA B6 and DR4. CONCLUSION: Homozygosity for these antigens, B6, DR4 and DR6, may enhance the expression of antisperm antibodies, and cause infertility.