Is sperm immunosuppressive in male homosexuals and vasectomized men?

Abstract

Recently a high incidence of uncommon diseases including Pneumocystis carinii pneumonia and Kaposis sarcoma have been observed among male homosexuals. Various cellular immune functions are impaired in these patients; the mechanism of the immunodeficiency is not known although it is believed that multiple viral infections and/or certain drugs such as nitrites which these patients use may be important. The authors suggest that one of the causes of immunosuppression could be the introduction of sperm into the vascular system. The repeated exposure of the immune system to germ-cell antigens and the synergistic effect of viruses and/or drugs may exert this effect. In laboratory experiments a number of cellular immune functions of sperm-injected mice were reduced including cytotoxic T-cell responses against hapten-modified self and alloantigens as well as mixed lymphocyte reactivity. Natural killer-cell function was also impaired. Sperm could gain access to the vascular system through: 1) intestinal or oral lesions which are found in most affected individuals and 2) increased permeability of the blood vesicles of the intestinal and/or oral mucosa. These conditions are also related to nitrite use; thus it is possible that this type of immunodeficiency is multi-factorial. The increased incidence of neoplasms among male homosexuals could provide an opportunity to investigate the relationship between immunodeficiency and tumor surveillance. In vasectomized males immune potential may be compromised by leakage of sperm into the vascular system; major histocompatiblity complex (MHC)-linked regulation of antisperm auto-antibody production after vasectomy has been reported in mice and men. Animal models will allow further investigation of this phenomenon including the synergistic effects of sperm virus and drugs and clinical studies could consider the role of MHC-linked genes the influence of age viral infection and drug usage.