Correlation between the Hypoosmotic SwellingT and DNA Fragmentation Assessed by the TUNEL Assay in Asthenozoospermia

Abstract

Objective: To study the correlation between the hypoosmotic swelling test (HOST) and DNA fragmentation in asthenozoospermia assessed by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphatebiotin nick end-labeling (TUNEL) assay. Methods: This cross-sectional study was conducted in 27 semen samples obtained from infertile men with asthenozoospermia. Both HOST and TUNEL assay were performed for each sample. The sperm swelling pattern and positive apoptosis staining of individual spermatozoa were evaluated. HOST and TUNEL scores, and the proportion of positive staining in each grade were calculated in each sample. Results: The results showed a negative correlation between HOST and TUNEL scores (r =-0.428, P = 0.026). Sperm swelling grade A had a higher incidence of positive apoptosis staining when compared with other grades (P < 0.01). There was no statistically significant difference in positive apoptotic staining between other grades; nevertheless, sperm swelling grade D tended to have a lower incidence of positive apoptosis staining. Conclusion: Based on the results of this study, HOST may be used as an optional test to identify DNA-intact spermatozoa whereby sperm with a grade D swelling pattern should be selected preferentially for intracytoplasmic sperm injection (ICSI), whereas sperm with a grade A swelling pattern should be avoided for ICSI.