Immunity to spermatozoa and male fertility.

Immunological characterization of semen and male fertility are discussed. The pH of seminal plasma is very similar in groups of fertile and infertile men. Nonspecific immunological factors such as lysozyme, C3c, alpha-1 antitrypsin and beta-2 microglobulin were significantly higher in 14% of infertile men. Seminal antibodies agglutinating spermatozoa are frequently observed in IgG and IgA isotypes. High levels of seminal anti-phospholipid antibodies in seminal plasma could influence epitopes on the endometrium, oocyte or early embryo in patients with repeated unexplained spontaneous miscarriages.