A study of sperm acrosin in patients with unexplained infertility.

Radioimmunoassay (RIA) and the fluorometric enzyme method (FEM) were used to study sperm acrosin levels of semen obtained from 13 men of known fertility (group I), 14 male partners of unexplained infertile couples (group II), 4 men among unexplained infertile couples who fathered a child during evaluation and follow-up (group III), and 13 oligospermic males (group IV). Using analysis of variance with the Student-Neuman Keuls post hoc comparisons, we found statistically significant differences between acrosin levels of groups I and II, groups I and IV, groups II and III, and groups III and IV (P less than 0.01) for each comparison and P less than 0.05 for entire experiment). Although RIA was found to be superior to the fluorometric technique, there was excellent correlation between the two methods (r = 0.7; P less than 0.001). This study suggests an association between low sperm acrosin levels and infertility.