Immunocompetent cells in human testis in health and disease

The authors have investigated lymphocyte subpopulations and macrophages in normal human testes and the testes of patients under investigation and treatment for subfertility. Specific monoclonal antibodies were used in an indirect immunoperoxidase technique. In normal tissues, T lymphocytes (Leu 4-positive cells) were present in the rete testis with a preponderance of cells of the suppressor/cytotoxic phenotype. In contrast, no lymphocytes were detected within the peripheral portions of the testis. Cells reacting with the anti-Leu M3 monoclonal antibody, which defines monocytes/macrophages, were detected in appreciable numbers in peripheral testis with a specific location around the seminiferous tubules. HLA-DR-positive cells (human leukocyte antigens--class II [DR] determinants of the major histocompatibility complex) also were identified and showed a similar pattern of distribution to that of the Leu-M3 positive cells. While no lymphocytes were seen in the normal peripheral testis, T lymphocytes were detected in testicular biopsies from subfertile patients. Suppressor/cytotoxic T cells (Leu 2a-positive) predominated in patients with oligozoospermia and obstructive azoospermia while T cells of the helper/inducer phenotype predominated in patients with unilateral testicular obstruction and in postvasectomy patients. Sperm antibody measurements correlated with these findings.