A new method for isolation of human antisperm antibodies

Summary. A study was undertaken to isolate pure human antisperm antibodies from the sera of infertile couples. One hundred infertile couples attending the Infertility and IVF Unit (Beilinson Medical Center) because of unexplained infertility were tested (both partners) for antisperm antibodies. Sixty‐eight experiments were performed with positive sera containing antisperm antibodies and normal donor sperm. These experiments were followed by experiments in order to elute pure human antisperm antibodies from the sperm surface. Three experiments were performed with human sperm which were found to be coated by antisperm antibodies, in order to directly elute these antibodies from the sperm surface. In all experiments we eluted antisperm antibodies of the IgG and IgA isotypes from the sperm surface. These antibodies were demonstrated in the eluate, in each case by either the indirect immunobead test, the radial immune diffusion assay, or the electrophoresis method. Control experiments were performed as follows: (i) normal donor sperm incubated with normal serum; (ii) normal donor sperm without serum incubation; (iii) normal donor lymphocytes incubated with serum containing antisperm antibodies; (iv) normal donor lymphocytes without serum incubation. No antisperm antibodies were obtained in any of these control experiments. Absorption and elution experiments can be used for the isolation of pure human antisperm antibodies, which may then be used for the production of anti‐idiotypic antibodies to antisperm antibodies. The anti‐idiotypic antibodies could be further utilized as antigen substitutes for the production of a contraceptive vaccine and/or for application in the treatment of spontaneous abortion and infertility.