Increased DNA Fragmentation in Patients with Infertility in Dakar (Senegal)

Abstract

The presence of DNA fragmentation in semen is associated with poor results in ART (Assisted Reproductive Technology). This has led to the introduction of sperm DNA integrity testing in the clinical assessment of male infertility. The TUNEL assay is one of the most commonly used tests to measure DNA fragmentation in research studies, but it is now being optimized for routine clinical use. So, the objectives of our study were to install the TUNEL assay in our laboratory and to use it to assess the degree of DNA fragmentation in our patients dealing with couple infertility. Forty seven (47) and 25 samples from patients followed up for infertility and known fertile men were analyzed between August 2013 and July 2015 respectively. The sperm samples were evaluated according to the World Health Organization Guidelines. Sperm DNA damage was assessed by the TUNEL assay, with a standardized protocol that we adapted for reading using fluorescence microscopy instead of flow cytometry. The Sperm DNA Fragmentation Index was significantly higher in patients with infertility compared to the controls (22.2% ± 5.6% vs. 16.7% ± 0.7%) with a p < 0.05. This Index was also high in patients with varicocele compared to the control group (22.8% ± 9.2 vs. 16.7% ± 0.7%) (p < 0.01). After establishing the ROC curve (Receiver Operating Characteristics curve), we found a 15% threshold of DNA fragmentation, separating the patients with infertility from the control group. In our study, a 15% threshold positivity of DNA fragmentation using the TUNEL assay was highly associated with infertility. The results indicate that high level DNA fragmentation is associated with infertility.

Male Infertility and Sperm DNA Fragmentation

“…Our results are consistent with the studies (Sergerie et al, 2005) [ 25 ] that found a DFI in the infertility group was significantly higher than in the fertile group (40.9 ± 14.3% compared to 13.1 ± 7.3%) and the mean sperm concentration in the infertile group was also significantly lower compared to the fertile group (62.9 ± 33.2 × 10 6 /ml compared to 102.4 ± 66.4 × 10 6 /ml). DFI can be used to distinguish infertile men from fertile men [ 26 ]. A man with DFI sperm ≥ 26.1% has 2.84 times higher risk for infertility than the male with DFI sperm of < 26.1%.…”

Varicocele and DNA Fragmentation in Senegalese Infertile Males—A Study of 95 Cases

“…In a previous study, we described the setting up of this protocol in our laboratory. We found a cut-off of 15% with an accuracy of 72.1% [15] to differentiate infertile men with DNA damage from healthy men.…”

“…The spermatozoon were then washed and resuspended in a (methanol/acetic acid) mixture and stored at -20˚C until run time (Carnoy II solution). The test was performed according to the protocol of our laboratory [15]. To permeabilize cells, we used a solution of Triton.…”

“…If we refer to Esfahani's review [14], individuals who have high DNA fragmentation in their semen samples should be prior to surgery. Varicocele is a treatable affection that represents in our practice, almost half of our patients dealing with male infertility [15]. The aim of our study was to evaluate DNA fragmentation among our patients and assess the association of varicocele with increased DNA fragmentation in our population.…”

Sperm DNA Fragmentation, Determined Using the Sperm Chromatin Dispersion (SCD) Test, A Study in Republic of Kosovo Population

“…Sperm DFI was significantly higher in patients with infertility compared to those of control (22.2±5.6% vs. 16.7±0.7%; p<0.05). From these results, it may be concluded that sperm DFI determination could be used to distinguish infertile men from fertile men (Diallo et al, 2015). Thus, it may be concluded that a man with sperm DFI of≥26.1% has 2.84 times greater risk for infertility than men with sperm DFI of<26.1%.…”