Infertility is defned as the inability to conceive after having unprotected intercourse for a year. Infertility is increasing worldwide and has various causes both in the male and the female partner. Immune reactions to sperm can contribute up to 2 30% of infertility. The sperm has both autoantigenic as well as isoantigenic potential, and is thus capable of p- ducing antisperm antibodies (ASAs) and sperm-reactive T cells in both infertile men and women. Also, over 75% vasectomized men produce autoantibodies to sperm that can cause a problem in regaining fertility even after successful...