Human histocompatibility (HL-A) antigens in semen and their role in reproduction.

Seminal plasma from 7 of 10 normal persons was found to inhibit anti-HL-A2, 3, 7, 8, and 12 antisera specifically. Inhibition by seminal plasma appeared quantitatively less than that by whole serum and even less than that by platelets from the same individuals. No decrease in the number of offspring was found due to increased numbers of HL-A incompatibilities of the male spouse in 67 normal couples. No clear decrease in the number of pregnancies was observed in normal women with lymphocytotoxic antibodies. A similar study with infertile persons may yet reveal a role for HL-A antigens in human reproduction.