Fertilization antigen-1 removes antisperm autoantibodies from spermatozoa of infertile men and results in increased rates of acrosome reaction

Objective: To determine if fertilization antigen (FA)-I will remove autoant ibodies from the surface of sperm cells of immunoinfertile men by immune ad sorption and permit an increased acrosome reaction (AR). Design: Prospective analytic study. Setting: University medical center. Patient(s): Men from 18 infertile couples with autoantibodies present on th eir spermatozoa. Intervention(s): Sperm samples after processing were examined for antibody binding and AR before and after adsorption with control medium or FA-1. Main Outcome Measure(s): Sperm-bound antibody was assessed by the immunobea d assay (immunoglobulin [Ig] A and IgG) and the AR by induction with ionoph ore A23187. Result(s): Adsorption with FA-1 compared with control medium increased immu nobead-free swimming sperm an average of 50%, and 76% for IgA and IgG antis perm antibodies, respectively, with 78%: and 100% of the 18 semen specimens increasing significantly. The AR rate increased an average of 10.3% compar ed with control medium and showed improvement in 78% of the sperm samples a fter FA-1 adsorption. Conclusion(s): The FA-1 sperm antigen appears to significantly free sperm c ells coated with autoantibodies in the semen of most infertile men examined . Reducing sperm-bound antibodies that inhibited the AR allowed the sperm c ells to undergo successful AR induction by calcium ionophore. (Fertil Steri l(R) 1990;71:256-60. (C) 1999 by American Society for Reproductive Medicine .).