Density differences between spermatozoa with antisperm autoantibodies and spermatozoa covered with antisperm antibodies from serum.

Autoantibody-carrying spermatozoa from infertile men were processed using a discontinuous Percoll gradient. The treatment yielded a sperm fraction with significantly reduced antibody loading on the sperm head but did not affect antibody binding to the sperm tail. The immunodepleted sperm preparation demonstrated fertilizing ability when used in in-vitro fertilization. Normal, antibody-free semen samples were coated in vitro with antisperm antibodies from serum, followed by Percoll gradient centrifugation. No significant separation of antibody-free spermatozoa was obtained, regardless of the antibody binding site.