Anti-GAPDHS antibodies: a biomarker of immune infertility.

Numerous investigations have focused on the detection of antisperm antibodies, which have a naturally occurring impact on male and female fertility. In this study, spermatogenic glyceraldehyde-3-phosphate dehydrogenase (GAPDHS) was considered to be a candidate biomarker of immune infertility. The concentrations of anti-GAPDHS antibodies in the sera of sterile individuals and fertile couples were measured by enzyme-linked immunosorbent assay. Sera were collected from immune infertile (n = 175) and fertile (n = 237) individuals and were screened by tray agglutination tests (TAT). Infertile sera were further divided into two groups according to the serum titers obtained by TAT (titers ≤ 1:8, n = 58; titers > 1:8, n = 117). The concentrations of anti-GAPDHS antibodies were significantly higher in the immune infertile group than in the fertile group and were much higher with regard to the increased degrees of sperm agglutination (titers > 1:8). Surprisingly, we found statistically significantly higher concentrations of antibodies in the sera of infertile men than in those of infertile women, and a similar statistical result was obtained in the sera when primary infertility was compared with secondary infertility. Thus, anti-GAPDHS antibodies seem to be a sensitive parameter in immune infertile detection and might be one of the main factors causing immune infertility. This factor might be valuable as an indicator in the clinical diagnosis and monitoring treatment of infertility.