Chronic immune stimulation by sperm alloantigens. Support for the hypothesis that spermatozoa induce immune dysregulation in homosexual males.

Putative, sperm-induced allogeneic immunization was correlated with immune dysregulation in a study of 30 asymptomatic, monogamously paired homosexual males. Evidence for allogeneic immunization existed among 19 of 26 homosexual males who were anal sperm recipients. No evidence for any form of alloimmunization was found in four exclusive sperm donors. Immune dysregulation in the form of a reduced effector/suppressor T-cell ratio (Te/Ts less than 1.0) was exclusively documented in eight anal-sperm-recipient homosexual males, five of whom also manifested evidence for allogeneic immunization. In three of those, immune dysregulation was further manifested by functional T-cell deficiency in the form of a subnormal (less than 50 cu mm) local graft-v-host reaction. Similar evidence for alloimmunization was associated with a reduced Te/Ts ratio (0.85) in the female of a heterosexual couple who routinely practiced anal intercourse. Based on these findings, we suggest that chronic, repeated exposure to sperm during anal intercourse results in a high frequency of allogeneic immunization and may play an important role in the development of acquired immune dysregulation among homosexual males.