Significance of sperm antibodies detected by the mixed antiglobulin reaction and the tray agglutination test

Summary. The most widely used tests to detect seminal and serum sperm antibodies are the mixed antiglobulin reaction (MAR as recommended by WHO) and the tray agglutination test (TAT). It has been suggested that the prognostic significance of sperm antibody tests might be influenced by a concomitant reduction of sperm numbers and/or sperm motility. Furthermore, the relative sensitivity of these sperm antibody tests to detect sperm antibodies is not known. We therefore compared TAT, performed with serum and MAR results retrospectively for 565 infertile patients and MAR IgA and MAR IgG results for 1189 infertile patients. The association of TAT and MAR results with changes in sperm number, morphology and motility was assessed for 565 and 1185 patients, respectively. The influence of MAR and TAT results on sperm cervical mucus penetration test (SCMPT) results was investigated for 349 and 434 patients, respectively. Whereas only 23% of all MAR IgG positive patients were also MAR IgA positive, 82% of all MAR IgA positive patients were also MAR IgG positive. There was a significant (P < 0.0001) correlation between serum TAT, and MAR results. Positive MAR and TAT results were not associated with reductions in sperm number, motility and morphology. There was a significant correlation between MAR IgG and MAR IgA results and the sperm cervical mucus penetration test (SCMPT) results. According to these results, the MAR IgG would be sufficient as an initial screening for seminal sperm antibodies. MAR IgG negative patients with strong indication for immunologic infertility should also be investigated with the MAR IgA and the serum TAT. Serum and seminal sperm antibodies do not seem to influence male fertility via reductions of sperm number, motility and morphology. However because of their significant influence on SCMPT results, MAR IgG and MAR IgA results seem to be of prognostic significance.