Increased sperm nuclear DNA damage in normozoospermic infertile men: a prospective study

Sperm DNA damage measured by sperm chromatin structure assay in men with a history of undescended testes

The aim of this study was to compare sperm DNA damage between men with a history of congenital undescended testis (UDT) and men with a history of acquired UDT. A long-term follow-up study of men with previous UDT was performed. Fifty men with congenital UDT who had undergone orchiopexy at childhood age, 49 men with acquired UDT after a 'wait-and-see'-protocol (e.g. awaiting spontaneous descent until puberty and perform an orchiopexy in case of non-decent), and 22 healthy proven fertile men were included. The DNA fragmentation index (DFI) using sperm chromatin structure assay (SCSA) was used to express the level of sperm DNA damage. Decreased fertility potential was considered if DFI was above 30%. Sperm DNA damage was not statistically different between cases of congenital and acquired UDT. DFI was significantly more often >30% in the complete group of men with congenital UDT (9/50; 18%) and in the subgroup with bilateral congenital UDT (3/7; 43%) in comparison with the controls (none) (p-value 0.049 and 0.01, respectively). Age at orchiopexy in congenital UDT had no statistical effect on DNA damage. In men with acquired UDT, DFI did not statistically differ between those having undergone orchiopexy and those experiencing spontaneous descent. This study supports the hypothesis that UDT is a spectrum representing both congenital UDT and acquired UDT. Sperm DNA damage at adult age is not influenced by age at orchiopexy in congenital UDT cases and by orchiopexy or spontaneous descent in acquired UDT cases.

Relationship of DNA integrity to HRG C633T SNP and ART outcome in infertile couples

The status of sperm DNA fragmentation, protamine deficiency, free thiols and disulphide bonds in colloid-selected samples and its relationship to ART outcome or HRG C633T SNP is not known. The objective of this study was to determine these relationships in spermatozoa from men with male factor or unknown factor infertility (n = 118) undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). Sperm DNA integrity was analysed by flow cytometry using three fluorescent probes (acridine orange, monobromobimane and chromomycin A3). Principal component analysis (PCA) was used to identify the parameters that most influenced fertility. The relationships of sperm DNA integrity with seminal parameters, HRG C633T SNP and ART outcome were established using ANOVA and t-test. Sperm concentration and yield after preparation accounted for 27% of the total variance; sperm DNA integrity (%DFI and disulphide bonds) accounted for 16% of the variance in men from infertile couples. Sperm %DFI was significantly higher (P < 0.05) in older men than in younger men. A significant difference (P < 0.01) was observed in %DFI between smokers and non-smokers. Sperm %DFI was significantly higher (P < 0.01) in male factor infertility compared to either female factor or unknown factor infertility while free thiols were significantly higher (P < 0.01) in unknown infertility factor. No significant difference was observed between IVF success/failure in any of the seminal parameters studied. There was a tendency for protamine deficiency to be higher and disulphide concentration to be lower in men with HRG 633T. Such assessments may provide additional useful information about the prognosis for ART outcome, although more research is needed before clinical guidelines can be provided.

Sperm DNA Integrity Test and Assisted Reproductive Technology (Art) Outcome

The objective of the study was to investigate the influence of sperm DNA fragmentation index (DFI) by DNA integrity test on pregnancy outcome and pregnancy loss after assisted reproductive technology (ART) procedure: autologous intracytoplasmic sperm injection (ICSI), donation eggs ICSI, and intrauterine insemination (IUI). We investigated men from 531 couples undergoing autologous ICSI procedure (n=416), from couples undergoing donation eggs procedure (n=39) and IUI (n=76). We performed the following interventions: semen analysis, DNA integrity test, embryo scoring by Gardner and Schoolcraft grading system (1999). The study showed no statistically significant differences between the group regarding pregnancy rate (χ2=0.55; p>0.05; OR=1.25, 95% Cl 1.23-1.46; p>0.05). However, with increased levels of DFI, the number of pregnancy losses became higher (including biochemical pregnancies and spontaneous abortions) at OR=5.65 (95% Cl 4.32-7.11; p=0.05). We examined the percentage of grade I blastocysts (by Gardner and Schoolcraft, 1999) before donation eggs embryo transfer and found a statistically significant correlation with both the DFI (χ2=7.80; p<0.05) and sperm morphology (χ2=6.14; p<0.05). Analysis of the relationship between DFI and IUI output (clinical pregnancy, miscarriage) revealed significant correlations in both directions: between DFI and pregnancy rate after IUI (χ2=6.29; p<0.05) and between the DFI and pregnancy development after IUI (χ2=6.87; p<0.05). The three group categories (autologous, heterologous ICSI procedures and IUI) studied showed that sperm samples with DFI>27% were associated with increased riskofearlypregnancyloss. Men with infertility should undergo DNA fragmentation assay in addition to the standard semen analysis. When DFI exceeds 27%, ICSI should be a method of choice, even in cases where the conventional parameters of semen analysis tests are normal.

Oxidative DNA Damage to Sperm Cells and Peripheral Blood Leukocytes in Infertile Men

BACKGROUND Oxidative DNA damage is associated with male infertility. The aim of this study was to evaluate the oxidative DNA damage of sperm cells and blood leukocytes and to determine the levels of MDA and NO levels in seminal and blood plasma of idiopathic infertile men. MATERIAL AND METHODS The study enrolled 52 patients, including 30 infertile and 22 fertile men. MDA, NO, and 8-OHdG/106dG were estimated using spectrophotometry and high-pressure liquid chromatography (HPLC)-based methods in seminal and blood plasma. The association with the sperm parameters was assessed, particularly sperm counts and motility. RESULTS The mean sperm concentration and sperm motility of the fertile men were significantly higher than that of the infertile men. The mean MDA and NO concentration in the seminal and blood samples of the infertile men were higher than that of fertile men. Also, the mean numbers of sperm cells and leukocytes 8-OHdG/106dG of the infertile men were significantly higher than that of fertile men (p=0.04 and p<0.001, respectively). Sperm motility and sperm count were negatively correlated with leukocyte and sperm cell 8-OHdG/106dG ratio. However, progressive motility was significantly negatively correlated with sperm cell and leukocyte 8-OHdG/106dG ratio (R=-0.357, p=0.026; R=-0.388, p=0.024, respectively). CONCLUSIONS Oxidative stress is an important factor in male infertility. Therefore, biochemical detection of 8-OHdG/106dG in sperm cells and blood leukocytes may be an additional tool in the diagnosis of male infertility.

Measuring Sperm DNA Fragmentation and Clinical Outcomes of Medically Assisted Reproduction: A Systematic Review and Meta-Analysis

Sperm DNA fragmentation has been associated with reduced fertilization rates, embryo quality, pregnancy rates and increased miscarriage rates. Various methods exist to test sperm DNA fragmentation such as the sperm chromatin structure assay (SCSA), the sperm chromatin dispersion (SCD) test, the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labelling (TUNEL) assay and the single cell gel electrophoresis (Comet) assay. We performed a systematic review and meta-analysis to assess the value of measuring sperm DNA fragmentation in predicting chance of ongoing pregnancy with IVF or ICSI. Out of 658 unique studies, 30 had extractable data and were thus included in the meta-analysis. Overall, the sperm DNA fragmentation tests had a reasonable to good sensitivity. A wide variety of other factors may also affect the IVF/ICSI outcome, reflected by limited to very low specificity. The constructed hierarchical summary receiver operating characteristic (HSROC) curve indicated a fair discriminatory capacity of the TUNEL assay (area under the curve (AUC) of 0.71; 95% CI 0.66 to 0.74) and Comet assay (AUC of 0.73; 95% CI 0.19 to 0.97). The SCSA and the SCD test had poor predictive capacity. Importantly, for the TUNEL assay, SCD test and Comet assay, meta-regression showed no differences in predictive value between IVF and ICSI. For the SCSA meta-regression indicated the predictive values for IVF and ICSI were different. The present review suggests that current sperm DNA fragmentation tests have limited capacity to predict the chance of pregnancy in the context of MAR. Furthermore, sperm DNA fragmentation tests have little or no difference in predictive value between IVF and ICSI. At this moment, there is insufficient evidence to recommend the routine use of sperm DNA fragmentation tests in couples undergoing MAR both for the prediction of pregnancy and for the choice of treatment. Given the significant limitations of the evidence and the methodological weakness and design of the included studies, we do urge for further research on the predictive value of sperm DNA fragmentation for the chance of pregnancy after MAR, also in comparison with other predictors of pregnancy after MAR.

Novel concepts in male factor infertility: clinical and laboratory perspectives

In recent years, the management of male factor infertility has undergone important changes with the introduction of novel concepts, advanced testing, and therapeutic interventions. This review highlights some of these changes and discusses their impact to routine clinical practice. First, we discuss the recent changes in the World Health Organization (WHO) laboratory methods and reference values for the examination of human semen. Second, we examine the role of sperm chromatin integrity tests in light of increasing evidence of the detrimental effect of sperm DNA fragmentation on reproductive outcomes. Third, we summarize the main findings of varicocele-related infertility and the outcomes of microsurgical varicocele repair to different case scenarios. Lastly, we critically discuss the current management of men with nonobstructive azoospermia seeking fertility and the new opportunities that emerged to help these men achieve biological fatherhood.

HT-COMET: a novel automated approach for high throughput assessment of human sperm chromatin quality

STUDY QUESTION

Can we make the comet assay (single-cell gel electrophoresis) for human sperm a more accurate and informative high throughput assay?

SUMMARY ANSWER

We developed a standardized automated high throughput comet (HT-COMET) assay for human sperm that improves its accuracy and efficiency, and could be of prognostic value to patients in the fertility clinic.

WHAT IS KNOWN ALREADY

The comet assay involves the collection of data on sperm DNA damage at the level of the single cell, allowing the use of samples from severe oligozoospermic patients. However, this makes comet scoring a low throughput procedure that renders large cohort analyses tedious. Furthermore, the comet assay comes with an inherent vulnerability to variability. Our objective is to develop an automated high throughput comet assay for human sperm that will increase both its accuracy and efficiency.

STUDY DESIGN, SIZE, DURATION

The study comprised two distinct components: a HT-COMET technical optimization section based on control versus DNAse treatment analyses ( ITALIC! n = 3-5), and a cross-sectional study on 123 men presenting to a reproductive center with sperm concentrations categorized as severe oligozoospermia, oligozoospermia or normozoospermia.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Sperm chromatin quality was measured using the comet assay: on classic 2-well slides for software comparison; on 96-well slides for HT-COMET optimization; after exposure to various concentrations of a damage-inducing agent, DNAse, using HT-COMET; on 123 subjects with different sperm concentrations using HT-COMET. Data from the 123 subjects were correlated to classic semen quality parameters and plotted as single-cell data in individual DNA damage profiles.

MAIN RESULTS AND THE ROLE OF CHANCE

We have developed a standard automated HT-COMET procedure for human sperm. It includes automated scoring of comets by a fully integrated high content screening setup that compares well with the most commonly used semi-manual analysis software. Using this method, a cross-sectional study on 123 men showed no significant correlation between sperm concentration and sperm DNA damage, confirming the existence of hidden chromatin damage in men with apparently normal semen characteristics, and a significant correlation between percentage DNA in the tail and percentage of progressively motile spermatozoa. Finally, the use of DNA damage profiles helped to distinguish subjects between and within sperm concentration categories, and allowed a determination of the proportion of highly damaged cells.

LIMITATIONS, REASONS FOR CAUTION

The main limitations of the HT-COMET are the high, yet indispensable, investment in an automated liquid handling system and heating block to ensure accuracy, and the availability of an automated plate reading microscope and analysis software.

WIDER IMPLICATIONS OF THE FINDINGS

This standardized HT-COMET assay offers many advantages, including higher accuracy and evenness due to automation of sensitive steps, a 14.4-fold increase in sample analysis capacity, and an imaging and scoring time of 1 min/well. Overall, HT-COMET offers a decrease in total experimental time of more than 90%. Hence, this assay constitutes a more efficient option to assess sperm chromatin quality, paves the way to using this assay to screen large cohorts, and holds prognostic value for infertile patients.

STUDY FUNDING/COMPETING INTERESTS

Funded by the CIHR Institute of Human Development, Child and Youth Health (IHDCYH; RHF 100625). O.A. is a fellow supported by the Fonds de la Recherche du Québec - Santé (FRQS) and the CIHR Training Program in Reproduction, Early Development, and the Impact on Health (REDIH). B.R. is a James McGill Professor. The authors declare no conflicts of interest.

Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay using bench top flow cytometer for evaluation of sperm DNA fragmentation in fertility laboratories: protocol, reference values, and quality control

PURPOSE

The purpose of this study is to provide a detailed protocol and quality control steps for measuring sperm DNA fragmentation (SDF) by terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) assay using a new bench top flow cytometer, determine the reference value of SDF, and assess sensitivity, specificity, and distribution of SDF in infertile men and controls with proven and unproven fertility.

METHODS

Semen specimens from 95 controls and 261 infertile men referred to a male infertility testing laboratory were tested for SDF by TUNEL assay using Apo-Direct kit and a bench top flow cytometer. Percentage of cells positive for TUNEL was calculated. Inter- and intraobserver variability was examined. TUNEL cutoff value, sensitivity, specificity, and distribution of different cutoff values in controls and infertile patients were calculated.

RESULTS

The reference value of SDF by TUNEL assay was 16.8 % with a specificity of 91.6 % and sensitivity of 32.6 %. The positive and negative predictive values were 91.4 and 33.1 %, respectively. The upper limit of DNA damage in infertile men was significantly higher (68.9 %) than that in the controls (19.6 %).

CONCLUSIONS

TUNEL assay using flow cytometry is a reproducible and easy method to determine SDF. At a cutoff point of 16.8 %, the test showed high specificity and positive predictive value. The results of this test could identify infertile men whose sperm DNA fragmentation does not contribute to their infertility and confirm that a man who tests positive is likely to be infertile due to elevated sperm DNA fragmentation.

Evaluating γH2AX in spermatozoa from male infertility patients

OBJECTIVE

To investigate whether γH2AX levels were different in the spermatozoa of healthy men compared with infertility patients, and to assess the possible correlations between γH2AX and conventional semen parameters and double-stranded breaks (DSBs) identified with the use of comet assay.

DESIGN

Prospective study.

SETTING

Clinical laboratory.

PATIENT(S)

Semen from 100 male infertile patients and 100 healthy sperm donors.

INTERVENTION(S)

Human sperm samples were analyzed in terms of World Health Organization parameters. The γH2AX levels were detected by means of flow cytometry. DSBs of sperm were detected by means of comet assay. Morphology slides were made and the sperm morphology assessed according to strict criteria.

MAIN OUTCOME MEASURE(S)

Conventional semen analyses, γH2AX levels in sperm, DNA DSBs in sperm, and correlations among γH2AX, conventional semen analyses, and DSBs.

RESULT(S)

Concentration, viability, motility, and normal sperm morphology were significantly lower in male infertility patients compared with healthy men. Also, γH2AX levels and the number of DSBs were significantly higher in the sperm of infertile subjects compared with healthy men. γH2AX levels correlated negatively with conventional semen parameters and positively with DSBs. A threshold γH2AX level of 18.55% was identified as a cutoff value to discriminate infertile subjects from fertile control subjects with a specificity of 86.0% and a sensitivity of 83.0%. The positive and negative predictive values of the 18.55% γH2AX threshold were high: 87.7% and 85.5%, respectively.

CONCLUSION(S)

γH2AX levels were higher in the sperm of male infertility patients than in healthy men. γH2AX levels in sperm, as evaluated with the use of flow cytometry, might be a useful biomarker for evaluating DSBs in human spermatozoa.

Chromosomal Abnormalities in Infertile Men from Southern India

BACKGROUND AND OBJECTIVE

Male infertility has been associated with aneuploidies and structural chromosomal abnormalities, Yq microdeletions and specific gene mutations and/or polymorphisms. Besides genetic factors, any block in sperm delivery, endocrine disorders, testicular tumours, infectious diseases, medications, lifestyle factors and environmental toxins can also play a causative role. This study aimed to determine the constitutional karyotype in infertile males having normal female partners in a south Indian population.

MATERIALS AND METHODS

A total of 180 men with a complaint of primary infertility ranging from 1 to 25 years were screened for chromosomal abnormalities through conventional analysis of GTG-banded metaphases from cultured lymphocytes.

RESULTS

Four individuals were diagnosed to have Klinefelter syndrome. Two cases exhibited reciprocal translocations and one showed a maternally inherited insertion. Polymorphisms were seen in sixty-seven patients (37.2%).

CONCLUSION

The occurrence of chromosomal abnormalities in 4.6% and variants involving the heterochromatic regions of Y, chromosome 9 and the acrocentric chromosomes in 38.2% of the infertile men with an abnormal seminogram strongly reiterates the inclusion of routine cytogenetic testing and counselling in the diagnostic work-up prior to the use of assisted reproduction technologies.

Engaging practicing gynecologists in the management of infertile men

In the modern era, contemporary management of male infertility has undergone groundbreaking changes with the introduction of new concepts, advanced testing, and therapeutic interventions. As practicing gynecologists are often the first physicians who encounter an infertile couple, it is essential that these clinicians are continuously updated about the new pearls and pitfalls of male infertility management. Semen analysis is commonly ordered by gynecologists. In 2010, the WHO released new cutoff reference values for the semen parameters adopting novel methodology, which has incited much debate. Reference values have been lowered in comparison with previous standards, with a direct clinical implication in decision-making strategies. Specialized sperm-function tests, such as sperm oxidative stress and sperm chromatin integrity assessments, became clinically available, thus offering an opportunity to better understand sperm dysfunctions concealed during routine semen analysis. Furthermore, the initial counseling of azoospermic men by an andrologically well educated gynecologist may alleviate the misconception and distress surrounding the false belief of sterility, and will clarify the available options of percutaneous and microsurgical sperm-retrieval techniques and assisted conception outcome. Regarding varicocele, which is commonly seen in infertile males, it is now clear that the best treatment option for infertile men with clinical varicocele is the microsurgical vein ligation. Natural conception is significantly improved after varicocelectomy, and recent data suggest that such treatment optimizes reproductive outcome of couples undergoing ICSI or micro-TESE sperm retrieval. Lastly, new therapeutic interventions, including oral antioxidant therapy and lifestyle modifications, have gained increasing attention, as they aid in alleviating male infertility.

Sperm nuclear DNA fragmentation and its association with semen quality in Greek men

Due to the limitations of conventional semen analysis in predicting a man's fertility potential, sperm DNA fragmentation was recently introduced as a novel marker of sperm quality. This prospective study was undertaken to investigate the associations between conventional seminal parameters and DNA fragmentation in Greek men. A total of 669 subject data were evaluated in two groups, normozoospermic (n = 184) and non-normozoospermic (n = 485), according to the WHO 2010 (WHO Laboratory Manual for the Examination and Processing of Human Semen, 5th edn. World Health Organization), reference limits. For all the subjects, semen volume, sperm concentration, total count, rapid and total progressive motility and morphology were recorded following the WHO 2010 methods and DNA fragmentation was assessed by the sperm chromatin dispersion assay. An inverse correlation was established between DNA fragmentation and all conventional seminal parameters except semen volume in men with seminal profiles below the reference limits, with statistical significance for rapid and total progressive motility. Normozoospermic men exhibited lower levels of DNA fragmentation than their non-normozoospermic counterparts, even though the values were not always below 30%. DNA fragmentation testing and traditional semen analysis should therefore be considered as complementary diagnostic tools in a comprehensive evaluation of male infertility.

The effect of sperm DNA fragmentation on live birth rate after IVF or ICSI: a systematic review and meta-analysis

A systematic review and meta-analysis was conducted to evaluate the relationship between the extent of sperm DNA damage and live birth rate (LBR) per couple and the influence of the method of fertilization on treatment outcome. Searches were conducted on MEDLINE, EMBASE and Cochrane Library. Six studies were eligible for inclusion in the meta-analysis. Overall, LBR increased signficantly in couples with low sperm DNA fragmentation compared with those with high sperm DNA fragmentation (RR 1.17, 95% CI 1.07 to 1.28; P = 0.0005). After IVF and intracytoplasmic sperm injection (ICSI), men with low sperm DNA fragmentation had significantly higher LBR (RR 1.27, 95% CI 1.05 to 1.52; P = 0.01) and (RR 1.11, 95% CI 1.00 to 1.23, P = 0.04), respectively. A sensitivity analysis showed no statistically significant difference in LBR between low and high sperm DNA fragmentation when ICSI treatment was used (RR 1.08, 95% CI 0.39 to 2.96; P = 0.88). High sperm DNA fragmentation in couples undergoing assisted reproduction techniques is associated with lower LBR. Well-designed randomized studies are required to assess the role of ICSI over IVF in the treatment of men with high sperm DNA fragmentation.

Fluctuation of "sperm DNA integrity" in accordance with semen parameters, and it's relationship with infertility

PURPOSE

Nowadays sperm analysis is used routinely to assess infertile men, but it's predictive value is still restricted. For this reason, new markers are needed for diagnosis and guide treatment. A DNA damage evaluation method, which is easily applicable for routine analysis is described in this paper to provide an important support in clinical evaluation.

METHODS

In this study, DNA damage evaluation was planned in infertile males with the COMET assay, a method which is simple, cheap, sensitive and reliable. For this purpose, the sperm DNA damage of normospermic, oligospermic, asthenospermic and teratospermic cases were investigated and the relationship between sperm parameters (sperm count, motility, morphology) and DNA damage was assessed.

RESULTS AND CONCLUSION

According to our results we suggest that the factors to blame for sperm DNA damage and semen quality are the same. Also it was found that the infertile males possess substantially more sperm DNA damage than fertile men do. Improving and using the DNA damage evaluation tests seem to improve the results in ART clinics.

A translational medicine appraisal of specialized andrology testing in unexplained male infertility

The diagnostic and prognostic validity of sperm function biomarkers is particularly relevant for males with unexplained infertility in which routine semen analysis fails to detect subcellular sperm dysfunctions. In this general review, we examine the role and significance of specialized andrology laboratory tests from past to present and provide a glance toward the future. We concluded that the assessment of sperm DNA damage and oxidative stress provide a relatively independent measure of fertility that yields diagnostic and prognostic information complementary to, but distinct and more significant than, standard sperm parameters. Since none of the available methods for such testing have been fully translated, further research is necessary to evaluate their cost-effectiveness when applied in large scale to daily medical practice. Application of translational medicine concepts would also be useful to accelerate the clinical application of recent discoveries in the fields of genomics, proteomics and metabolomics.

Diagnostic accuracy of sperm chromatin dispersion test to evaluate sperm deoxyribonucleic acid damage in men with unexplained infertility

OBJECTIVE

To compare the sperm chromatin dispersion (SCD) test and the terminal uridine nick-end labeling (TUNEL) assay for assessment of sperm DNA damage.

DESIGN

Prospective comparative experimental study.

SETTING

Andrology laboratory.

PATIENT(S)

Twenty subfertile men with unexplained infertility.

INTERVENTION(S)

Sperm DNA damage was determined in the same semen samples using the TUNEL assay with fluorescence microscopy and the SCD test with bright-field microscopy.

MAIN OUTCOME MEASURE(S)

Correlation coefficient and receiver operating characteristic analysis outcomes. The TUNEL assay was used as the reference standard to identify optimal cutoff points for assessing DNA damage by SCD.

RESULT(S)

The SCD test detected a significantly higher proportion of sperm with damaged DNA (20.6% ± 14.0%) than the TUNEL assay (11.5% ± 7.3%). Spearman's rank correlation showed that the methods were not comparable (r = 0.29). Receiver operating characteristic analysis revealed that 15% was the best SCD cutoff point to classify patients within the same levels of DNA fragmentation, normal or abnormal, as determined by the TUNEL assay, with an accuracy of 69%.

CONCLUSION(S)

The SCD test is more sensitive than the TUNEL assay for the assessment of DNA damage in men with unexplained infertility. Although the methods are poorly correlated, SCD may discriminate men with normal and abnormal sperm DNA damage with moderate accuracy when compared with TUNEL. It is important to distinguish between the methods because they differently evaluate sperm DNA damage.

Evaluation of human sperm chromatin status after selection using a modified Diff-Quik stain indicates embryo quality and pregnancy outcomes following in vitro fertilization

Sperm chromatin/DNA damage can be measured by a variety of assays. However, it has been reported that these tests may lose prognostic value in Assisted Reproductive Technology (ART) cycles when assessed in post-prepared samples, possibly due to the normalizing effect promoted by sperm preparation procedures. We have recently implemented a modified version of the Diff-Quik staining assay that allows for the evaluation of human sperm chromatin status in native samples, together with standard sperm morphology assessment. However, the value of this parameter in terms of predicting in vitro fertilization (IVF) and Intracytoplasmic sperm injection (ICSI) outcomes after sperm selection is unknown. In this study, data from 138 couples undergoing in vitro fertilization (IVF) or Intracytoplasmic sperm injection (ICSI) treatments showed that sperm chromatin integrity was significantly improved after density gradient centrifugation and swim up (p < 0.001), but no correlations were found with fertilization or embryo development rates (p > 0.05). However, sperm samples presenting lower percentages of damaged chromatin were associated with better quality (Grade I) embryos in both ART procedures (p < 0.05) and clinical pregnancy among IVF couples (p < 0.05). Furthermore, regression analysis confirmed the clinical value of Diff-Quik staining in predicting IVF (but not ICSI) clinical pregnancy (OR: 0.927, 95% CI: 0.871-0.985, p = 0.015), and a threshold value of 34.25% for this parameter was established. The proportion of IVF couples achieving a clinical pregnancy was reduced 1.9-fold when the percentage of abnormal dark staining was ≥34.25% (p = 0.05). In conclusion, the Diff-Quik staining assay provides useful information regarding ART success, particularly in IVF cycles, where some degree of 'natural' sperm selection may occur; but not in ICSI, where sperm selection is operator dependent. This quick and low-cost assay is suggested as an alternative method to detect sperm chromatin status in minimal clinical settings, when no other well-established and robust assays (e.g. Sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling) are available.

Sperm DNA fragmentation assay by sperm chromatin dispersion (SCD): correlation between DNA fragmentation and outcome of intracytoplasmic sperm injection

Purpose

The aim of the present study was to investigate the relationship between sperm DNA fragmentation index (sDFI) and outcome of intracytoplasmic sperm injection (ICSI).

Methods

All the patients were divided into two groups based on sperm DNA fragmentation analysis by the sperm chromatin dispersion (SCD) method. A total of 237 patients were in the DNA fragmentation normal group (sDFI ≤ 30 %), and 140 patients were in the DNA fragmentation abnormal group (sDFI ≥ 30 %). The relationship of sDFI with the outcome of ICSI was analyzed.

Results

A significant difference in semen parameters was observed between the DNA fragmentation normal and abnormal groups [count, motility and morphology (p < 0.05)]. However, no significant difference was seen between the number of oocytes retrieved and fertilization rates between the two groups, whereas the number of embryos progressed to day 3 and the blastocyst formation rate in the remaining embryos after transfer were significantly more in the DNA fragmentation normal group (p < 0.05). A significant negative correlation was noted between DFI values of more than 30 % and number of pregnancies and deliveries (p < 0.05). A higher DFI was also associated with increased abortion rates.

Conclusions

In the present study, sperm with DNA fragmentation showed a negative correlation with semen parameters. Further, sperm with damaged DNA have potential adverse effects on embryo progression, clinical pregnancy rate, and ongoing pregnancies.

[Diagnosis of male infertility: a need of functional and chromatin evaluation]

OBJECTIVES

To evaluate the incidence of functional and chromatin alterations on spermatozoids in patients grouped according to normality of standard semen parameters based on the 5th edition of the World Health Organization (WHO) guidelines. To identify and correlate the most frequently altered characteristics in the normal standard semen parameters sub-population.

MATERIALS AND METHODS

A prospective study was performed. It evaluated standard semen parameters (volume, sperm concentration, motility and morphology, round cells, peroxidase-positive cells) according to WHO guidelines, as well as functional tests (24 hours survival, hypoosmotic swelling test, modified stress test), and additional assays (aniline blue, nitroblue-tetrazolium, TUNEL) in 110 semen samples from patients and 6 from fertile donors (control). Based on standard semen parameters values, patients were divided into two groups (A: all standard parameters normal; B: one altered standard parameter at least).

RESULTS

At least one of the variables analyzed was altered in 96.61% of the samples. Groups A and B showed statistically significant differences in all the complementary tests. At least one of the complementary tests were altered in 93.68% of the samples in group A, and the most frequently affected variable was sperm DNA fragmentation (16.95%).

CONCLUSIONS

Performing a more in-depth seminal study within the routine functional and chromatin assays provides a more precise diagnosis of male infertility. The WHO standards should be considered as a primary approach.

Effects of reduced seminal enzymatic antioxidants on sperm DNA fragmentation and semen quality of Tunisian infertile men

PURPOSE

To evaluate levels of sperm DNA fragmentation and enzymatic antioxidant status in seminal plasma of Tunisian fertile and infertile men in order to assess the effects of seminal oxidative stress on sperm DNA integrity and semen quality.

METHODS

Semen samples from 100 infertile patients (40 oligoasthenoteratozoospermics, 31 teratozoospermics and 29 asthenozoospermics) and 50 fertile men (controls) were analyzed for DNA fragmentation by TUNEL assay and biochemical parameters. Seminal antioxidant activities (Superoxide dismutase, Glutathione peroxidase and Catalase) and malondialdehyde concentrations were measured spectrophotometrically.

RESULTS

Sperm DNA fragmentation and malondialdehyde levels in infertile groups were more elevated than controls. Nevertheless, the activities of the antioxidant enzymes were significantly lower in abnormal groups compared to normozoospermics. Sperm DNA fragmentation was closely and positively correlated to malondialdehyde levels (r = 0.37, P = 0.008); meanwhile, reduced seminal antioxidant profile was negatively associated to sperm DNA fragmentation. Interestingly, we noted also that sperm DNA fragmentation was negatively correlated to sperm motility (r = -0.54, P < 0.001) and positively associated to the abnormal sperm morphology (r = 0.57, P = 0.002).

CONCLUSIONS

This report revealed that increased sperm DNA fragmentation can be due to the impaired seminal enzymatic antioxidant profile and increased Lipid peroxidation. Our results sustain that the evaluation of sperm DNA fragmentation and seminal oxidative biomarkers in infertile men is recommended as a consistent prognostic tool for male infertility assessment.

Are sperm DNA fragmentation, hyperactivation, and hyaluronan-binding ability predictive for fertilization and embryo development in in vitro fertilization and intracytoplasmic sperm injection?

OBJECTIVE

To determine the diagnostic value of the following sperm function tests in predicting the fertilizing ability of spermatozoa in conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI): hyaluronan-binding assay (HBA), DNA fragmentation (Halosperm), and hyperactivity.

DESIGN

Prospective study.

SETTING

University medical center.

PATIENT(S)

133 couples undergoing infertility treatment with IVF/ICSI.

INTERVENTION(S)

Analysis of sperm DNA fragmentation, hyaluronan-binding ability, and hyperactivation on washed semen samples used for the insemination of oocytes.

MAIN OUTCOME MEASURE(S)

Correlation between the results of sperm function tests and the fertilization rate (FR) or embryo quality (EQ) after IVF and ICSI. Comparison of the sperm DNA fragmentation, hyperactivation, and hyaluronan binding ability between cycles with less than 50% (group 1) and more than 50% (group 2) of oocytes fertilized after IVF.

RESULT(S)

Both FR and EQ in IVF cycles negatively correlated with sperm DNA fragmentation. Furthermore, a positive correlation was observed between FR and hyaluronan-binding ability or induced hyperactivity. The semen samples from the IVF cycles with low FR (group 1) were characterized by statistically significantly higher sperm DNA fragmentation and lower hyaluronan-binding ability in comparison with semen samples from the group with high levels of fertilization (group 2). In ICSI cycles, no relationship was found between sperm function tests and FR or EQ.

CONCLUSION(S)

The Halosperm test, the HBA test, and induced hyperactivity are useful in predicting the ability of spermatozoa to fertilize oocytes in IVF and are helpful in distinguishing semen samples suitable for IVF or ICSI.

Cryopreservation of Ram Semen Facilitates Sperm DNA Damage: Relationship Between Sperm Andrological Parameters and the Sperm Chromatin Structure Assay

We hypothesized that cryopreservation and incubation in conditions that mimic the female genital tract following insemination increases the susceptibility of ram sperm DNA to denaturation. Ram sperm samples (n = 12) underwent the sperm chromatin structure assay (SCSA) and semen quality tests, including motility parameters, viability, and chlortetracycline fluorescence (CTC) patterns. We also assessed correlations between SCSA variables and semen quality parameters. Analyses were performed for both fresh and cryopreserved samples at 0, 3, and 20 hours of incubation in synthetic oviductal fluid (SOF; 39 degrees C, 5% CO(2)). The SCSA variables, mean alpha t (X alpha(t)) and standard deviation of alpha t (SD alpha(t)), were higher because of cryopreservation (P <.05, P <.001, respectively) after 20 hours in SOF. For both fresh and frozen spermatozoa, SCSA values (X alpha(t), SD alpha(t), and the percentage of cells outside the main population of alpha(t) [%COMP alpha(t)]) increased during incubation in SOF. Motility was negatively correlated with both SD alpha(t) and %COMP alpha(t), ranging from -0.39 (P <.01) to -0.59 (P <.001) for both fresh and cryopreserved semen; viability also was negatively correlated with X alpha(t), SD alpha(t), or %COMP alpha(t) (-0.36; P <.05, -.40 and -.46; P <.01, respectively) in fresh semen. The %COMP alpha(t) was positively correlated to the percentage of CTC pattern AR (P <.001) and negatively correlated to the percentages of patterns F and B (-0.33 to -0.60, P <.05 to P <.001). Variation among ejaculates within ram was observed (P <.01). Cryopreservation clearly facilitates DNA damage in physiological conditions. The low to moderate correlations between SCSA variables and classical semen quality parameters indicate that the SCSA provides additional information to standard tests for evaluating ram sperm quality.

Sperm DNA damage: how relevant is it clinically?

PURPOSE OF REVIEW

The true impact of the current sperm DNA fragmentation testing needs further scrutiny to assess whether clinically meaningful information is conveyed.

RECENT FINDINGS

Various studies have suggested different or no threshold values with assorted tests for the percentage of DNA fragmentation in the ejaculated sperm above which natural conception, fertilization or embryo development and/or clinical pregnancy rates are compromised. Current DNA fragmentation assessment methods provide very little specific information on the nature and severity of the DNA damage detected. Although sperm DNA fragmentation is associated with lower pregnancy rates through natural conception or intrauterine insemination, it does not seem to affect intracytoplasmic sperm injection outcome. Although animal studies demonstrated adverse reproductive effects of sperm DNA fragmentation, any conclusive evidence in humans is yet to be demonstrated. It is not clear whether interventions aimed at enrichment of sperm with decreased DNA fragmentation are effective in preventing the potential adverse effects of sperm DNA fragmentation in humans. Major concern about the use of sperm DNA integrity tests as prognostic parameters is that the direct evaluation of DNA fragmentation in individual sperm fertilizing the oocyte is not possible.

SUMMARY

The lack of consensus in defining a clinically relevant standard DNA fragmentation test with a meaningful cut-off level brings challenges in implementing the routine use of sperm DNA integrity assessment in daily practice.

Assessment and treatment of repeated implantation failure (RIF)

Repeated implantation failure (RIF) is determined when embryos of good quality fail to implant following several in vitro fertilization (IVF) treatment cycles. Implantation failure is related to either maternal factors or embryonic causes. Maternal factors include uterine anatomic abnormalities, thrombophilia, non-receptive endometrium and immunological factors. Failure of implantation due to embryonic causes is associated with either genetic abnormalities or other factors intrinsic to the embryo that impair its ability to develop in utero, to hatch and to implant. New methods of time-lapse imaging of embryos and assessment of their metabolic functions may improve selection of embryos for transfer, and subsequent outcomes for IVF patients, as well as for those diagnosed with RIF. This review discusses the various causes associated with RIF and addresses appropriate treatments.

Is there an association between HOST grades and sperm quality?

BACKGROUND

Intracytoplasmic sperm injection (ICSI) is the primary treatment for male infertility. However for this procedure, with the exception of visual morphological selection, there is no standardization for sperm selection. Recently, the hypo-osmotic swelling test (HOST) has been proposed to potentially select sperm with intact membranes. The aim of this study is to evaluate the ability of this technique to select functional sperm in terms of apoptosis and morphology, as well as nuclear integrity.

METHODS

A total of 20 semen samples were randomly collected from men who attended the Andrology Unit of the Isfahan Fertility and Infertility Center. Semen samples were washed and exposed to hypotonic conditions, before being fixed and simultaneously assessed for membrane integrity as well as abnormal morphology, DNA fragmentation and protamine deficiency by using Papanicolaou, TUNEL and CMA3 staining techniques, respectively. The remaining semen samples were washed with calcium buffer and stained by Annexin V, then exposed to hypotonic conditions before being assessed for early apoptosis along with membrane integrity.

RESULTS

HOST grade 'd', followed by grade 'c', showed the highest percentages of healthy sperm, whereas sperm of HOST grade 'g' in which anomalies in terms of apoptosis, abnormal head morphology or nuclear immaturity or membrane damage, were most frequently observed in the samples assessed.

CONCLUSIONS

Integration of HOST into the sperm selection procedure may provide a valuable tool for selection of functional sperm required for ICSI. According to this study, insemination of HOST grade 'g' sperm should be avoided during ICSI.

Apoptotic sperm biomarkers and their correlation with conventional sperm parameters and male fertility potential

PURPOSE

To investigate the relationship between sperm apoptotic biomarkers and patient clinical characteristics, conventional sperm parameters and fertility potential.

MATERIAL AND METHODS

Sperm analysis, phospholipid asymmetry, mitochondrial membrane potential (MMP) and DNA denaturation were assessed in 142 males of infertile couples. Seventy-three couples were allocated to the natural conception group, and 55 couples underwent IVF or ICSI.

RESULTS

DNA denaturation correlated positively with age and negatively with testicular volume (TV). MMP correlated negatively with BMI and FSH and positively with TV. Normal viable sperm correlated positively with TV and negatively with age, BMI and FSH. DNA denaturation was associated with a significantly lower natural pregnancy rate (OR 5.4, 95% CI:1.3-22, p = 0.011).

CONCLUSION

Sperm apoptosis is related to male age, BMI, testicular volume and FSH. Among the apoptotic markers, only DNA denaturation has been found to predict natural pregnancy better than conventional sperm parameters.

Male fertility: psychiatric considerations

OBJECTIVE

To examine: 1) current knowledge on normal biologic variation of seminal parameters; 2) how stress and psychological factors affect sperm quality in fertile and infertile males; and 3) how mental illness and psychopharmacologic agents can affect male fertility.

DESIGN

English-language Medline, Embase, and Psycinfo were searched for relevant publications (from 1970 to January 2011) for systematic review.

SETTING

None.

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Possible effects of stress, mood, and psychotropic medications on male factor fertility.

RESULT(S)

Male-factor infertility is influenced by myriad factors (obesity, tobacco, etc.). Stress alone may reduce testosterone levels and spermatogenesis. Infertility assessment and treatment can lead to distress and negatively affect sperm samples. Available research has failed to control for potentially confounding variables.

CONCLUSION(S)

Although some trends have been identified, larger-scale studies that adequately control all confounding variables are needed before conclusions can be made about the relationship between stress, psychotropic agents, and male infertility.

Sperm DNA integrity assessment: a new tool in diagnosis and treatment of fertility

Infertility affects 15% of all couples. Although male infertility factors with reduced semen quality are contributing to about half of all involuntary childlessness, the value of standard semen parameters in prediction of fertility in vivo and choice of proper method for assisted reproduction is limited. In the search for better markers of male fertility, during the last 10 years, assessment of sperm DNA integrity has emerged as a strong new biomarker of semen quality that may have the potential to discriminate between infertile and fertile men. Sperm DNA Fragmentation Index (DFI) as assessed by the flow cytometric Sperm Chromatin Structure Assay (SCSA) can be used for evaluation of sperm chromatin integrity. The biological background for abnormal DFI is not completely known, but clinical data show that DFI above 30% is associated with very low chance for achieving pregnancy in natural way or by insemination, but not in vitro. Already when the DFI is above 20%, the chance of natural pregnancy may be reduced, despite other sperm parameters being normal. Thus this method may explain a significant proportion of cases of unexplained infertility and can be beneficial in counselling involuntary childless couples need of in vitro fertilisation.

Increased receptor for advanced glycation end products in spermatozoa of diabetic men and its association with sperm nuclear DNA fragmentation

Although the majority of patients with diabetes have disorders in sexual function, associations between diabetes mellitus and sperm function at the molecular level are largely unknown. As receptor for advanced glycation end products plays a key role in many diabetic complications, we hypothesised that it may be involved in sperm nuclear DNA fragmentation. RAGE levels were determined using ELISA and western blot analysis in sperm samples from 32 diabetic and 35 nondiabetic men. Sperm DNA fragmentation was assessed using TUNEL assay. Diabetic men had significantly higher mean levels of RAGE protein (P < 0.001) and DNA fragmentation (P < 0.001) in spermatozoa. Sperm RAGE was directly correlated to sperm DNA fragmentation in diabetic men (r = 0.81, P < 0.001). The high positive correlation between RAGE levels and nuclear DNA fragmentation in spermatozoa of diabetic men suggests a central role of RAGE in disturbances in sexual function of diabetic men.

Sperm DNA integrity assays: diagnostic and prognostic challenges and implications in management of infertility

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.

[The influence of diabetes mellitus on male reproductive function: a poorly investigated aspect of male infertility]

Whilst diabetes mellitus is known to have many systemic complications, male infertility, beyond impotence, retrograde ejaculation and hypogonadism, has not been widely recognised to be one of them. Due to the paucity of studies and inconsistencies regarding the condition's impact on semen quality, few fertility specialists consider the condition noteworthy. As a consequence little information exists as to its prevalence amongst infertile men. Recently the prevailing view has been challenged by findings showing that diabetes induces subtle molecular changes that are important for sperm quality and function. Diabetic men have been found to have a significantly higher percentage of sperm with nuclear DNA damage, a factor known to be associated with compromised fertility and increased miscarriage rates. The mechanism by which this diabetes-related sperm nDNA damage occurs remains unknown. The identification of high levels of advanced glycation end products (AGEs) and their receptor (RAGE) throughout the male reproductive tract coupled to changes in testicular metabolite levels and spermatogenic gene expression suggest that glycation may play an integral role in oxidative stress which in turn causes sperm nDNA damage. As glycation is a normal consequence of life and has been implicated in DNA fragmentation in a variety of seemingly unconnected conditions, it may constitute a common mechanism for the damage seen in sperm DNA.

[Assisted reproductive techniques: key procedures and results in Germany and Europe]

The wide application of in vitro fertilization (IVF) since the 1980s years has revolutionized the treatment of infertility. Since then more than four million babies have been born following IVF. Diversification of the original IVF has led to many new techniques. Besides the basic procedures such as intrauterine insemination (IUI), IVF and intracytoplasmic sperm injection (ICSI), new techniques such as cryopreservation and genetic analysis have become an integral part of reproductive medicine. This moves patients into the focus of ART who are not "classic" infertility patients. Cryopreservation of unfertilized oocytes and ovarian tissue offers cancer patients the opportunity to preserve fertility. Genetic analysis on polar bodies or embryonic cells can help patients with genetic diseases or carriers of genetic disorders towards a healthy child.

Sperm chromatin structure assay (SCSA): a tool in diagnosis and treatment of infertility

Diagnosis of male infertility has mainly been based on the World Health Organization (WHO) manual-based semen parameter's concentration, motility and morphology. It has, however, become apparent that none of these parameters are reliable markers for evaluation of the fertility potential of a couple. A search for better markers has led to an increased focus on sperm chromatin integrity testing in fertility work-up and assisted reproductive techniques. During the last couple of decades, numerous sperm DNA integrity tests have been developed. These are claimed to be characterized by a lower intraindividual variation, less intralaboratory and interlaboratory variation and thus less subjective than the conventional sperm analysis. However, not all the sperm chromatin integrity tests have yet been shown to be of clinical value. So far, the test that has been found to have the most stable clinical threshold values in relation to fertility is the sperm chromatin structure assay (SCSA), a flow cytometric test that measures the susceptibility of sperm DNA to acid-induced DNA denaturation in situ. Sperm DNA fragmentation as measured by SCSA has shown to be an independent predictor of successful pregnancy in first pregnancy planners as well as in couples undergoing intrauterine insemination, and can be used as a tool in investigation, counseling and treatment of involuntary childlessness. More conflicting data exist regarding the role of sperm DNA fragmentation in relation to fertilization, pre-embryo development and pregnancy outcome in in vitro fertilization and intracytoplasmic sperm injection (ICSI).

Relationship between advanced glycation end products and increased lipid peroxidation in semen of diabetic men

AIMS

Majority of diabetic male patients have disturbances in their reproductive systems. However, the mechanisms underlying these disturbances are largely unknown. Since advanced glycation end products (AGE) have a key role in oxidative stress and cell damage in diabetic complications, we hypothesize that AGEs may be involved sperm lipid peroxidation.

METHODS

total AGEs in seminal plasma of 32 diabetic and 35 non-diabetic men was determined by spectrofluorimetric method and carboxy methyl lysine (CML) level was assayed using ELISA. Contents of lipid peroxidation in sperm and seminal plasma were determined by thiobarbituric acid reaction. Total antioxidant capacity (TAC) was measured by a colorimetric assay.

RESULTS

total AGEs were found significantly higher in seminal plasma of diabetic men than non-diabetic group (p<0.001) whereas no significant differences in seminal plasma CML values between two groups was observed. Moreover, sperm and seminal plasma lipid peroxidation were significantly higher in diabetic subjects than non-diabetic men and a significantly lower TAC was detected in diabetic group compare to non-diabetics.

CONCLUSIONS

these results showed an increment in AGEs in seminal plasma of diabetic subjects and may suggest a key role for glycation process and increased oxidative stress in reproductive system dysfunction.