Flow Cytometry for Assessing Human Sperm Acrosomal Reaction (AR) and Correlation of AR and Acrosomal Enzyme Activity With Semen Parameters.

Abstract

Background/aim: This study aimed to evaluate human sperm acrosomal reaction (AR) using flow cytometry and examine the correlation of AR and acrosomal enzyme activity (AEA) with seven semen parameters: total sperm count, concentration, vitality, motility, morphology, survival rate, and sperm DNA fragmentation index (DFI).

Patients and methods: A retrospective analysis was conducted on semen data from 398 men in the AR group and 526 men in the AEA group. AR was assessed using flow cytometry, while AEA was measured with the solid-phase BAPNA method. Correlations between AR, AEA, and the seven semen parameters were analyzed. Subgroups based on standard reference values were also compared.

Results: AEA demonstrated significant positive correlations with total sperm count, concentration, vitality, motility, morphology, and survival rate, and a negative correlation with DFI (p<0.05). In contrast, AR correlated only with sperm concentration. Subgroup analyses revealed that in the AR group, the lower subgroup correlated with concentration and vitality, while the normal subgroup correlated only with concentration. In the AEA group, the normal subgroup showed significant correlations with all seven parameters, while none were found in the lower subgroup. The normal subgroup exhibited significantly higher total count, concentration, vitality, motility, morphology, and survival rate, and lower DFI (p<0.05). No significant differences were observed between the normal and lower AR subgroups, except for survival rate (p>0.05).

Conclusion: AEA shows stronger and more consistent correlations with semen parameters compared with AR, suggesting its potential as a reliable marker for evaluating male fertility. Further research is needed to clarify the predictive value of AR in male fertility assessment.