The apoptotic pathway in fertile and subfertile men: a case-control and prospective study to examine the impact of merocyanine 540 bodies on ejaculated spermatozoa.

Objective: To evaluate the presence of merocyanine 540 (M540) bodies and their impact on the measurement of apoptotic biomarkers in human spermatozoa.

Design: Case-control, prospective study.

Setting: Academic centers.

Patient(s): Fertile and subfertile subjects.

Intervention(s): Semen samples from subfertile and fertile men, 11 per group, were analyzed for basic semen parameters and early (annexin-V binding) and late (terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL]) sperm apoptotic biomarkers by flow cytometry. Samples were also stained with M540 to assess the presence of M540 apoptotic bodies.

Main Outcome Measure(s): Presence of M540 apoptotic bodies.

Result(s): Groups differed significantly in the expression of early and late apoptosis biomarkers. The percentage of M540 bodies between groups was not different. The exclusion of M540 bodies from TUNEL results did not have a significant impact on measurement in either fertile or subfertile groups.

Conclusion(s): This study confirmed the occurrence of M540 bodies in semen and that male factor infertility is associated with an increased expression of apoptosis biomarkers. Moreover, we demonstrated that the presence of M540 bodies did not affect the quantification of apoptotic biomarkers in either group.