Influence of microsurgical varicocelectomy on human sperm mitochondrial DNA copy number: a pilot study.

BACKGROUND: There is good evidence to show that varicocele repair can improve conventional sperm parameters, as well as, sperm DNA integrity, in infertile men with a clinical varicocele. OBJECTIVE: To examine the effect of varicocelectomy on sperm quality, specifically, sperm nuclear chromatin integrity and sperm mitochondrial DNA (mtDNA) copy number. DESIGN, SETTING, AND PARTICIPANTS: A prospective study done between March 2007 and January 2008. We evaluated a consecutive series of infertile men (n = 14) presenting to Ovo clinic with one year or more history of infertility, a clinically palpable varicocele and poor motility (<25 % rapid progressive and <50 % progressive). SURGICAL PROCEDURE: Microsurgical sub-inguinal varicocelectomy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Conventional sperm parameters, sperm mtDNA copy number (by real time PCR) and sperm chromatin structure assay (SCSA) parameters (%DFI,% HDS) before and 4 months after microsurgical varicocelectomy. RESULTS AND LIMITATIONS: Sperm concentration and SCSA parameters (%DFI and %HDS) improved significantly after surgery (P < 0.05). Sperm mitochondrial DNA copy number decreased significantly after surgery (27 ± 30 to 9 ± 6 copies per sperm, respectively, P = 0.032). There was a significant negative correlation between mitochondrial DNA copy number and sperm motility (r = - 0.71, P = 0.002). CONCLUSION: These findings support the concept that correction of a varicocele can improve spermatogenesis and sperm function, as mitochondrial DNA copy number has been suggested to reflect the efficiency of spermatogenesis and has been inversely related to sperm motility.

Anti-sperm antibodies are not associated with sperm DNA damage: a prospective study of infertile men.

Infertile men have poorer sperm DNA integrity than do fertile men, and this damage may contribute to reducing male reproductive potential. However, the etiology of this damage has not been fully characterized. We sought to examine the relationship, if any, between anti-sperm antibodies and sperm DNA damage in a consecutive series of non-azoospermic, infertile men in order to determine whether anti-sperm antibodies (ASAs) may contribute to sperm DNA damage. We conducted a prospective study on consecutive semen samples obtained from men (n=75) presenting for infertility evaluation. Sperm concentration, motility, strict morphology, ASA levels (by direct mixed agglutination reaction, expressed as the percentage of spermatozoa with IgG or IgA antibodies) and sperm DNA damage (by sperm chromatin structure assay) were evaluated. Mean (+/-SD) sperm concentration and progressive motility were significantly lower in ASA-positive (>40% of sperm coated with ASAs) compared to ASA-negative samples (23.4+/-13.1 x 10(6)/mL and 27+/-15% vs. 74.6+/-61.2 x 10(6)/mL and 46+/-18%, respectively, P<0.05). Sperm progressive motility was inversely correlated with the percentage of IgG-bound (r=-0.33) and IgA-bound spermatozoa (r=-0.25). In contrast, sperm %DNA fragmentation index and percent normal forms were not significantly different in ASA-positive compared to ASA-negative samples (17.5+/-17.9% and 7.5+/-3.0% vs. 17.4+/-13.5% and 6.5+/-2.6%, respectively). The data indicate that ASAs are not associated with sperm DNA damage and suggest that ASAs are unlikely to have a significant direct or indirect effect on sperm DNA integrity.

The histone to protamine ratio in human spermatozoa: comparative study of whole and processed semen.

Sperm protamine deficiency has been demonstrated in some infertile men and may be an important determinant of sperm DNA integrity. We sought to examine and compare the sperm nuclear histone to protamine ratio in whole and processed semen samples from fertile and infertile men.