A modified acrosome induction test.
Many types of acrosome induction tests require special equipment and reagents that are not available to most clinicians; thus, simpler tests seem desirable. A modified acrosome induction test has been developed that uses basic reagents and a light microscope, which are available in most office settings. A hypoosmotic swelling test and a double stain (Bismark brown and rose Bengal) were combined to evaluate the viable acrosome reaction (AR) among 74 infertile men and 42 control men. The study included 34 infertile males without varicoceles, 20 with nonrepaired varicoceles and 20 with repaired varicoceles. On each test day, a specimen from a fertile donor was run as a control. The spontaneous acrosome reaction was recorded in semen before and after capacitation. The final % viable acrosome reaction equaled the capacitated value minus the spontaneous value for whole semen. The mean % viable AR among the control specimens was 16% with no values less than 10%. This mean value for controls was significantly greater than the mean % viable AR in each patient group. There were no overlaps in the 95% confidence intervals. When the study group was stratified according to normal acrosome induction tests or >10% viable AR, 30 patients had a normal test and 44 had abnormal tests. Six patients with varicoceles and an abnormal acrosome induction test had a varicocelectomy, and 2 (33%) converted their acrosome induction test to normal after at least 6 months of follow-up. Nine patients had in vitro fertilization (IVF), 3 had a poor result, and all had an abnormal acrosome induction test. Six had a good result with IVF and all 6 had a normal acrosome induction test. Thus, the acrosome induction test described in this report may be performed in any office laboratory to detect subtle male factor problems. The results may be helpful for planning IVF, intracytoplasmic sperm injection, or varicocele surgery for infertile men.