Clinical significance of sperm DNA damage threshold value in the assessment of male infertility.
ABSTRACT Sperm DNA integrity is a prerequisite for normal spermatozoal function. The aim of the study was to evaluate the role of sperm chromatin damage, its cut-off level and its effect on sperm parameters in men with idiopathic infertility by analyzing 100 idiopathic infertile men and 50 fertile controls. Semen samples were analyzed as per WHO 1999 guidelines and sperm chromatin structure assay (SCSA) was applied to measure DNA fragmentation index (DFI) in sperm. The mean DFI of infertile men (35.75) was significantly (P < .0001) higher as compared to controls (26.22). The threshold level of 30.28% was obtained as cut-off value to discriminate infertile men from fertile controls. Sperm count, forward motility, and normal morphology found to be negatively associated with DFI in overall study subjects. Infertile men with severe oligozoospermia had higher mean DFI (40.01 ± 11.31) than infertile men with oligozoospermia (35.11 ± 10.05) and normal sperm count (33.99 ± 9.96). Moreover 64% of infertile men have DFI > 30 against 6% of fertile controls (P < .0001). Higher sperm DNA fragmentation may be the underlying cause for poor semen quality in idiopathic infertile men and the threshold value of 30.28% is a clear discriminator to distinguish infertile men from fertile men of Indian population. Thus, DFI is a good prognostic marker as cases with higher sperm DFI may have poor success rate even after assisted conception and may experience recurrent pregnancy loss (RPL) and should be counseled accordingly.
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ABSTRACT: Sperm is not a simple carrier of paternal genetic information but its role extends clearly beyond fertilization. Integrity of sperm genome is an essential pre-requisite for birth of healthy offspring and evaluation of sperm should entail DNA integrity analysis. DNA integrity analysis is a better diagnostic and prognostic marker of sperm reproductive potential. Conventional semen analysis emphasizes on sperm concentration, viability, motility and morphology and has been proven to be a poor indicator of reproductive potential and pregnancy outcome. To overcome the drawbacks associated with conventional semen analysis more useful fertility tests and molecular biomarkers have been explored. Among the different tests which have evolved for assessing the sperm reproductive potential, tests for sperm DNA quality are most promising. Sperm DNA damage has been closely associated with numerous indicators of reproductive health including fertilization, embryo quality, implantation, spontaneous abortion, congenital malformations and childhood diseases. It therefore has great potential as a prognostic test for both in vitro and in vivo conception. This review presents an updated account of tests that have better diagnostic and prognostic implications in the evaluation of sperm DNA damage. The basic principles, outline of methodology, advantage, disadvantage, clinical significance of each technique and implications of these tests have been discussed. The logistics of each test with respect to available resources and equipment in an andrology laboratory, the feasibility of performing these tests in routine diagnostic workup of infertile men and the opportunities and challenges provided by DNA testing in male fertility determination are also presented.Journal of Assisted Reproduction and Genetics 09/2011; 28(11):1073-85. · 1.82 Impact Factor
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ABSTRACT: Background: This case-control study was designed with the aim of evaluating the role of sperm, oxidative stress and DNA damage in idiopathic recurrent pregnancy loss (iRPL). This pilot study is the first study done on the Indian population which reports the association between DFI, TAC and ROS in couples experiencing iRSA. Methods: Twenty infertile men with a history of iRPL and 20 fertile controls (having father-ed a child a year earlier) were included in the study which was performed in Laboratory for Molecular Reproduction and Genetics, India, from March 2010 to July 2011. The female partners of the participants were normal on gynaecological examination and had normal endocrine and blood profiles. Conventional semen analysis was performed (concentration, motility, morphology; WHO criteria, 2010) within 1 hour of sample collection. Levels of reactive oxygen species (ROS) were assessed by luminol-dependant chemiluminescence. The total antioxidant capacity (TAC) was quantified by ELISA. The Sperm chromatin structure assay (SCSA) was performed by flow cytometry to determine DNA fragmentation Index (DFI). Statistical analysis was performed using SPSS version 15 and parameters were compared by Mann-Whitney test. Pearson correlation test was used to find the correlation between parameters and a p-value <0.05 was considered significant. Receiver operating characteristics (ROC) curve analysis was applied to find out the cut-off value of DNA frag-mentation index. Results: No significant differences in age, seminal volume, liquefaction time, pH and sperm concentration were observed between the male partner of iRPL cases and the controls, but sperm morphology and motility were significantly (p <0.05) lower in the male partner of cases with idiopathic recurrent spontaneous abortion (RSA). The mean ROS levels observed were 47427.00 relative light unit (RLU)/min/20 million sperm in the male partners as com-pared to 13644.57 RLU/ min/20 million sperm in the controls (normal <15000 RLU/min/20 million). The mean TAC levels in the controls (6.95 mM trolox) were significantly (p <0.05) higher as compared to the male partners of women with IRPL (2.98 mM trolox). The average mean DFI of male partners were found to be 23.37±9.9 and the mean DFI of controls was 13.89±5.40. The mean DFI was significantly (p <0.05) higher when compared to the con-trols. The range of DFI in male partners was 8.50−44.07. However, in the controls the range was 7.70–23.50. Conclusion: Sperm DNA integrity is critical for normal embryonic development and birth of healthy offspring. Oxidative stress due to the imbalance between raised free radical levels and low total antioxidant capacity is one of the critical causes of DNA damage. Thus assay of oxidative stress and sperm genomic integrity is essential in couples with iRSA following natural and spontaneous conception.J Reprod Infertil. 01/2011; 1212:267-276.
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ABSTRACT: The integrity of the sperm genome and epigenome are critical for normal embryonic development. The advent of assisted reproductive technology has led to an increased understanding of the role of sperm in fertilization and embryogenesis. During fertilization, the sperm transmits not only nuclear DNA to the oocyte but also activation factor, centrosomes, and a host of messenger RNA and microRNAs. This complex complement of microRNAs and other non-coding RNAs is believed to modify important post-fertilization events. Thus, the health of the sperm genome and epigenome is critical for improving assisted conception rates and the birth of healthy offspring.08/2012;