Antisperm antibody detection using concurrent cytofluorometry and indirect immunofluorescence microscopy

Anti-sperm antibodies from serum and seminal plasma were detected by concurrent flow cytometry and epifluorescence microscopy using fluorescein-conjugated antihuman immunoglobulins. Experimental conditions were designed, taking advantage of several monoclonal antisperm antibodies, to test aspects of the assay before clinical application. Perturbation of membrane integrity altered both the localization of binding and the number of sperm cells positive for bound antibodies. In specimens from selected infertility patients, 21.6% of the females and 40.8% of the males had significant levels of antisperm antibodies. Differences in the incidence of isoimmunity between female partners of antibody-positive or antibody-negative males and differences in the localization of antigens targeted by serum versus seminal plasma antibodies in men support the idea that, in some cases, immunity to sperm cells may be the result of altered sperm antigens.