Sperm parameters, protamine deficiency, and apoptosis in total globozoospermia

Background: Globozoospermia is a severe form of teratozoospermia (incidence < 0.1%) in infertile men that is characterized by round headed sperm and acrosomeless in semen.
Objective: To compare the semen parameters, protamine deficiency, and apoptosis in ejaculated spermatozoa between globozoospermic and normozoospermic men.
Materials and Methods: Thirty six semen samples were divided into two groups including 15 infertile men with total globozoospermic (> 90% round-headed sperm) and 21 healthy donors with normal spermograms as controls. Semen analysis was performed according to World Health Organization criteria (2010). Sperm protamine deficiency was assessed using Chromomycin A3 (CMA3) staining and the rate of apoptotic spermatozoa was evaluated with TUNEL assay.
Results: Sperm concentration, motility, and normal morphology in globozoospermic men were significantly decreased compared with controls (p<0.05). The rate of CMA3-reacted spermatozoa (CMA3+) in globozoospermic men was higher than controls (65.93 ± 11.77 vs. 21.24 ± 7.37, respectively, p<0.0001). The rate of apoptotic spermatozoa (TUNEL positive) were significantly increased in globozoospermic cases with respect to the controls (17.60 ± 10.72 and 5.95 ± 3.02, respectively, p<0.0001). There was no significant correlation between sperm protamine deficiency and apoptosis in globozoospermic men.
Conclusion: Globozoospermic samples contain a higher proportion of spermatozoa with abnormal chromatin packaging and DNA fragmentation than normozoospermic samples. Therefore, in addition to absence of acrosome in the spermatozoa of globozoospermic patients, the high percentage of spermatozoa with immature chromatin and apoptotic marker may be considered as the other etiologies of infertility in these patients.