Immunomagnetic separation of antibody-labelled from antibody-free human spermatozoa as a treatment for immunologic infertility. A preliminary report

A method is described where superparamagnetic polymer microspheres coated with monoclonal antibodies are used to isolate antibody-labelled from antibody-free spermatozoa in male autoimmune infertility. Autoimmune sperm samples or antibody-free spermatozoa adsorbed with antisperm-antibodies from sera were incubated with microspheres coated with a specific monoclonal antibody to murine immunoglobulins, after their preincubation with mouse anti-human IgG and IgA. Using a magnet, the microsphere-labelled spermatozoa were separated from the samples. Immunobead binding was performed before and after the treatment in order to detect changes in the percentage of antibody-bound spermatozoa. After the immunomagnetic separation, approximately 50% of the IgA-labelled spermatozoa was isolated while no difference was demonstrated when antisperm antibodies of IgG class were involved. The evaluation of sperm motility and membrane integrity after treatment seemed to indicate that the technique did not have any relevant effect on sperm characteristics. The fact that only a partial success in separation of IgA-bound spermatozoa and no success for IgG-labelled sperm was obtained indicates that the method needs to be improved before its clinical utilization might be postulated.