Human sperm antigens and antisperm antibodies I. Studies on vasectomy patients

Abstract

This study documents the types and incidence of antisperm antibody, detectable by indirect immunofluorescence, in 114 patients before vasectomy, 112 at 2 months and 71 patients at 6-9 months after vasectomy. Indirect immunofluorescence techniques revealed antibodies to seven distinct sperm antigens. Five of these antigens were readily accessible to antibody in vitro, and the remaining two were accessible only after treatment of spermatozoa with dithiothreitol and trypsin. Antisperm antibodies were detected in 61% of patients before vasectomy. The incidence rose to 77% at 2 months and 90% at 6-9 months after vasectomy. These antibodies were distinguishable into two groups based on their incidence before vasectomy. The first group included antibodies to antigens in the acrosome with a diffuse distribution, the equatorial region, the postacrosomal region and the midpiece of the tail. Its incidence was 61% before vasectomy; increased to 73% at 2 months and 80% at 6-9 months after vasectomy. The second group included antibodies to the sperm nucleus, the tail and to discrete antigens over the acrosome. They were found rarely (3%) in patients before vasectomy; increased in incidence to 25% at 2 months and 55% at 6-9 months after vasectomy. Antisperm antibodies of both groups existed as IgG and IgM classes; an exception being antibodies to sperm nucleus which were almost exclusively IgG. Of the antibodies, 14% were found to fix complement in vitro. Other autoantibodies, including antinuclear, antimitochondrial and antismooth muscle antibodies, did not develop following vasectomy.

PIP: The types and incidence of antisperm antibody were studied before, and 2 and 6-9 months after vasectomy, by indirect immunofluorescence techniques. Antisperm antibodies were detected in over 60% of the men between the ages of 22-51. Antibodies to 7 distinct sperm antigens were found, 5 of which were detectable by antibody in vitro, while the remaining 2 were detectable only after treatment of spermatozoa with dithiothreitol and trypsin. The incidence of antisperm antibodies rose from 61% before vasectomy, to 77% at 2 months and 90% at 6-9 months after vasectomy. 2 general classes of antibodies were established on the basis of their incidence prior to vasectomy. The 1st group (natural antibodies) included antibodies to antigens in the acrosome with a diffuse distribution, the equatorial region, the postacrosomal region, and the mid-section of the tail. The incidence of this class of antibody increased from 61% before vasectomy to 73% at 2 months and 80% at 6-9 months. The second class (immune antibodies) included antibodies to the sperm nucleus, the tail, and to discrete antigens over the acrosome. These increased from 3% before vasectomy to 25% at 2 months and 58% at 6-9 months. Both classes could be classified as both IgM and IgG, with the exeption of antibodies to sperm nucleus, which were almost exclusively IgG. Autoantibodies such as antinuclear, automitochondrial, and anti-smooth muscle antibodies did not develop after vasectomy.