Histoincompatibility in couples with unexplained infertility

Class I human leukocyte antigens (HLA-A, -B) and class II (HLA-DR) antigens were determined in 18 carefully selected couples suffering from unexplained infertility and subsequently compared with 30 normal fertile couples with no history of secondary sterility and with a control group consisting of randomly matched women and men from our laboratory cell panel. No significant differences in the frequencies of HLA antigens were detected between infertile and control groups. The frequency of shared HLA-A, -B, and -DR antigens among members of the couples was similar in all the groups. Finally, the one-way mixed lymphocyte culture showed normal reactivity of both infertile parental pairs in all combinations tested.