Reduced levels of T suppressor/cytotoxic lymphocytes in semen from vasovasostomized men: relationship to sperm autoantibodies.

The regulation of lymphocyte populations in semen and their function remains unknown. Using monoclonal antibodies and immunohistochemical techniques we compared the levels of mononuclear cells in ejaculates obtained from 14 men with intact vas deferens and 13 men who had undergone both a vasectomy and a microsurgical vasovasostomy. The presence of antisperm antibodies was also assessed by the immunobead binding assay. Semen from both groups contained about 10(3) T and B lymphocytes and monocytes. In men with intact vasa, T suppressor/cytotoxic cells predominated. In contrast, in vasovasostomized men the levels of T suppressor/cytotoxic cells were significantly reduced (P less than 0.005) and T helper/inducer cells predominated in their semen. Concentrations of seminal T helper/inducer lymphocytes, B lymphocytes and monocytes were similar in both groups. Antisperm antibodies were detected on sperm, in seminal fluid and/or in serum of all the vasovasovasostomy patients but in none of the controls, T suppressor/cytotoxic cells may limit the immune response to sperm within the male reproductive tract. Chronic obstruction resulting in damage to the integrity of the excurrent ducts may induce alterations in T cell regulation leading to a decrease in T suppressor/cytotoxic cells and create conditions permissive for the formation of autoantibodies to sperm-specific antigens.