Do men with prostate abnormalities (prostatitis/benign prostatic hyperplasia/prostate cancer) develop immunity to spermatozoa or seminal plasma?

Abstract

Prostate is an immunocompetent and not an immunoprivileged organ. It has an active immunologic armamentarium. There are three major prostate abnormalities namely, prostatitis, benign prostatic hyperplasia (BPH) and prostate cancer. In all these abnormalities, infection/inflammation has been implicated. As infection/inflammation of the male genital tract can also be involved in induction of antisperm antibodies (ASA), this study was conducted to examine if these prostate abnormalities lead to the formation of ASA. Sera were obtained from normal healthy men (n = 20), men with chronic prostatitis (n = 20), men with BPH (n = 25), men with prostate cancer (n = 25) and immunoinfertile men (n = 10). The presence of antisperm antibodies against lithium diiodosalicylate (LIS)-solubilized human sperm extract (HSE), seminal plasma and synthetic peptides based upon sperm-specific antigens namely fertilization antigen (FA-1) and YLP₁₂, were analysed using the sperm immobilization technique (SIT), tray agglutination technique (TAT), enzyme-linked immunosorbent assay (ELISA) and indirect immunobead binding technique (IBT). All the sera from normal men and men with prostate abnormalities (chronic prostatitis/BPH/prostate cancer) were found to be negative in SIT and TAT. In ELISA, a few sera from men having prostate abnormalities (4–24%) showed a weak positive immunoreactivity (2–3 SD units) with some of the spermatozoa/seminal plasma antigens. Majority of the samples did not show any immunoreactivity (<2 SD units) in ELISA. Even the samples that showed a weak positive immunoreactivity in ELISA did not bind to live human sperm in IBT, indicating lack of sperm binding antibodies in these sera. In all these assays, the sera from immunoinfertile men were positive. Our findings indicate that chronic prostatitis, BPH and prostate cancer do not induce antibodies to spermatozoa, sperm-specific antigens and seminal plasma components. Although prostate is an immunologically competent organ, and its abnormalities cause a rise in circulating prostate-specific antigen (PSA), it appears that there is no concomitant induction of immunity to spermatozoa/seminal components including sperm-specific fertility-related antigens, thus not causing ASA-induced immunoinfertlity. This is the first study to our knowledge reporting the absence of ASA in men with BPH and prostate cancer.