Impaired production of alpha and gamma interferon in asymptomatic homosexual males.

In vitro production of alpha interferon and gamma interferon was examined in cell cultures from 90 asymptomatic homosexual males and 19 healthy heterosexual male controls. The production of alpha and gamma interferon was significantly suppressed in homosexuals as compared to that in heterosexual controls (p less than 0.005 and p less than 0.001, respectively). Forty-one of the homosexuals produced less gamma interferon than any of the heterosexual controls. Antibodies against the human immune system virus (HIV) were found in eight homosexuals, who produced significantly less alpha and gamma interferon than did the HIV-seronegative homosexuals (p less than 0.02). Neither carriage of Entamoeba histolytica or Giardia lamblia nor serological evidence of infection with cytomegalovirus, Epstein-Barr virus or hepatitis B virus was associated with a significantly lower production of interferon than that found in homosexual males seronegative for these infections. No correlation was found between number of partners or practice of passive anal intercourse and production of interferons in homosexual men. It is concluded that the significantly lower production of both alpha and gamma interferon in asymptomatic homosexual males may play an important role in susceptibility to viruses, including HIV.