Beneficial effect of microsurgical varicocelectomy on human sperm DNA integrity

Relationship between varicocele and sperm DNA damage and the effect of varicocele repair: a meta-analysis

Varicocele, a cause of male infertility, occurs in nearly 40% of infertile males. It has been postulated that varicoceles may cause sperm DNA damage. Sperm DNA integrity has been recognized as one of the important determinants of normal fertilization and embryo growth in natural and assisted conception. Eighty-three human studies were identified after an extensive literature search involving the role of varicoceles in sperm DNA damage. Of the 83 studies, 12 were selected that measured similar types of reactive sperm DNA damage. Seven studies determined the damage of sperm DNA in varicocele-associated patients and six studies evaluated the efficacy of varicocelectomy. One study was a duplicate because both outcomes were included. Data were analysed using RevMan software. The overall estimate showed that patients with varicoceles have significantly higher sperm DNA damage than controls, with a mean difference of 9.84% (95% CI 9.19 to 10.49; P<0.00001). A varicocelectomy can improve sperm DNA integrity, with a mean difference of -3.37% (95% CI -4.09 to -2.65; P<0.00001). In conclusion, there is increased sperm DNA damage in patients with varicoceles and varicocelectomy may be a possible treatment; however, more studies with appropriate controls are needed to confirm this finding. A varicocele is an important cause of male infertility and occurs in nearly 40% of infertile males. The recent understanding of the effect of varicoceles in male reproduction has led some researchers to postulate varicoceles as the possible cause of sperm DNA damage. Eighty-three human studies were identified after an extensive literature search involving the role of varicoceles in sperm DNA damage. Of the 83 studies, 12 were selected that measured similar types of reactive sperm DNA damage by a similar method. Seven studies determined the damage of sperm DNA in varicocele-associated patients and six studies evaluated the efficacy of varicocelectomy. One study was a duplicate because both outcomes were included. The data were then entered in the RevMan software for analysis. The overall estimate showed that patients with varicoceles have significantly higher sperm DNA damage than controls, with a mean difference of 9.84% (95% CI 9.19 to 10.49; P<0.00001). A varicocelectomy can improve sperm DNA integrity, with a mean difference of -3.37% (95% CI -4.09 to -2.65; P<0.00001). Based on the results, it can be concluded that there is increased sperm DNA damage in patients with varicoceles and that varicocelectomy may be a possible treatment; however, more studies with appropriate controls are needed to confirm this finding.

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.

Novel concepts in male infertility

Extraordinary advances have been achieved in the field of male infertility in the last decades. There are new concepts in sperm physiology and several modern tools for the assessment of spermatogenesis kinetics in vivo. New tests using molecular biology and DNA damage assays allow the clinician to correctly diagnose men so far classified as having idiopathic male infertility. In the field of treatment, microsurgery has increased success rates either for reconstruction of the reproductive tract or the retrieval of spermatozoa for assisted conception. Emerging evidence suggests that life-style and environmental conditions are of utmost importance in male fertility and subfertility. This review discusses several concepts that have changed over the last years, such as the duration of the spermatogenic cycle in humans, Y-chromosome infertility, the reproductive potential of non-mosaic Klinefelter syndrome men, the impact of paternal age and sperm DNA in male infertility, the role of antioxidants in the treatment of infertile men, the predictive factors and techniques for sperm retrieval in non-obstructive azoospermia, and the microsurgical treatment of clinical varicoceles. Whenever possible, levels of evidence are provided as suggested by the Oxford Center of Evidence-based Medicine.

High total acrosin activity in varicocele individuals

Varicocele is a common cause of male infertility and reports indicate that varicocelectomy has a beneficial effect on male fertility. The aims of this study were to evaluate and compare the total acrosin activity along with DNA integrity in semen samples obtained from 70 varicocele individuals with male factors infertility presenting grades II and III varicocele before and after the surgery and 30 fertile individuals without any clinical presentation of varicocele. Total acrosin activity, protamine deficiency, DNA fragmentation, and semen parameters including sperm concentration, motility and sperm morphology were assessed by spectrophotometery, CMA3 staining, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay and WHO criteria, respectively. Total acrosin activity (P = 0.03), percentage CMA3 positivity (P = 0.00) and TUNEL-positive spermatozoa (P = 0.04) were higher in the varicocele individuals before the surgery compared with the fertile individuals; yet, all the aforementioned criteria decreased significantly after surgery (P < 0.05). The results of this study reveal that DNA fragmentation and protamine deficiency, as negative parameters in fertility, improve post-surgery; however, total acrosin activity as a positive parameter in fertility is higher in the varicocele individuals compared with fertile and decreases to a value close to the fertile control post-surgery. High levels of total acrosin activity in varicocele individuals need more research in future.

Poor sperm quality and advancing age are associated with increased sperm DNA damage in infertile men

With increasing evidence for faulty paternal contribution to reproduction, there has been a steady increase in studies highlighting an association between sperm DNA damage, failed/delayed fertilisation and aberrant embryo development. Owing to prevailing ambiguity, the aims of the study were to analyse the genetic integrity of the male gamete and then to understand its association with age, standard semen parameters, lifestyle and occupational factors. The study included 504 subjects, attending university infertility clinic for fertility evaluation and treatment. Semen characteristics were analysed by standard criteria; terminal deoxynucelotidyl transferase-mediated nick end-labelling assay was employed for DNA damage assessment. The average incidence of sperm DNA damage in patients with normozoospermic semen parameters was <10%. Patients with oligozoospermia, severe oligozoospermia, oligoasthenoteratospermia, asthenoteratozoospermia and necrozoospermia had significantly higher level of sperm DNA damage (P < 0.001). Patients above 40 years of age had significantly high levels of DNA damage (P < 0.001) compared with their counterparts. Patients with varicocele and a history of alcohol consumption had higher incidence of spermatozoa with DNA damage (P < 0.01). Poor sperm characteristics in the ejaculate are associated with increased sperm DNA damage. Age-related increase in sperm DNA damage and association of the same with varicocele and alcohol consumption are also demonstrated.

Are varicoceles associated with increased deoxyribonucleic acid fragmentation?

OBJECTIVE

To perform a literature search on the association between varicocele and sperm DNA fragmentation.

DESIGN

Systematic review.

PATIENT(S)

Men with a varicocele and infertility.

INTERVENTION(S)

Varicocele repair.

MAIN OUTCOME MEASURE(S)

Does the presence of a varicocele increase seminal oxidative stress and sperm DNA fragmentation?

RESULT(S)

In men with a varicocele increased levels of reactive oxygen species and sperm DNA damage can be found. This is probably related to defective spermatogenesis in these patients. Seminal oxidative stress is believed to be the source of sperm DNA damage. Patients with a varicocele and oligospermia may also have a diminished seminal antioxidant capacity. After varicocele repair sperm DNA fragmentation decreases.

CONCLUSION(S)

Varicocele is associated with sperm DNA damage, and this sperm pathology may be secondary to varicocele-mediated oxidative stress. The beneficial effect of varicocelectomy on sperm DNA damage further supports the premise that varicocele may impair sperm DNA integrity.

Zaditen (Ketotifen), as mast cell blocker, improves sperm quality, chromatin integrity and pregnancy rate after varicocelectomy

Surgery is considered the most common choice for the treatment of male infertility with clinical varicocele. Increased numbers of mast cells (MCs) have been associated with different types of infertility, including varicocele. Despite there being different reports on improved fertility following administration of MC blockers, there is no report on the effect of a MC blocker on varicocele or after varicocelectomy. Therefore, the aim of this study was to evaluate the effect of Zaditen on semen quality, protamine content, DNA damage and fertility post-surgery. The study included 103 infertile men who were referred to Isfahan Fertility and Infertility Center for varicocelectomy. Varicocele individuals were randomly divided into control (52) and treatment groups (51). Semen parameters, WBC/mL, protamine content (chromomycin A3 staining) and DNA integrity (sperm chromatin dispersion test) were assessed before and 3 months after surgery. Comparison of the aforesaid parameters between the two groups revealed significant improvement in the treatment group compared with the control group, with the exception of DNA integrity. In addition, the cumulative pregnancy significantly improved by 9 months post-surgery in the treatment group (41.17%) compared with the control group (21.15%). The results of this study, for the first time, reveal that MC blockers such as Zaditen improve semen parameters, chromatin integrity and pregnancy rates when administered as adjunct therapy post-varicocelectomy.

Management options of varicoceles

Varicocele is one of the most common causes of male infertility. Treatment options for varicoceles includes open varicocelectomy performed at various anatomical levels. Laparoscopic varicocelectomy has been established to be a safe and effective treatment for varicoceles. Robotic surgery has been introduced recently as an alternative surgical option for varicocelectomy. Microsurgical varicocelectomy has gained increasing popularity among experts in male reproductive medicine as the treatment of choice for varicocele because of its superior surgical outcomes. There is a growing volume of literature in the recent years on minimal invasive varicocele treatment with percutaneous retrograde and anterograde venous embolization/sclerotherapy. In this review, we will discuss the advantages and limitations associated with each treatment modality for varicoceles. Employment of these advanced techniques of varicocelectomy can provide a safe and effective approach aiming to eliminate varicocele, preserve testicular function and, in a substantial number of men, increase semen quality and the likelihood of pregnancy.

Sperm chromatin condensation in infertile men with varicocele before and after surgical repair

OBJECTIVE

To assess sperm chromatin integrity in infertile men with varicocele before and after surgical repair.

DESIGN

Prospective.

SETTING

Academic setting.

PATIENT(S)

Seventy-two infertile men with varicocele compared with 20 healthy fertile men.

INTERVENTION(S)

History taking, genital examination, semen analysis, sperm chromatin condensation assessment by aniline blue stain before and 3 months after varicocelectomy.

MAIN OUTCOME MEASURE(S)

Stained sperm heads (abnormal chromatin condensation) before and 3 months after varicocelectomy.

RESULT(S)

The mean percentage of aniline blue-stained sperm heads was significantly higher in infertile men with varicocele compared with fertile controls. The mean percentage of stained sperm heads was significantly decreased in infertile men with varicocele 3 months after surgery compared with the preoperative data. There was a significant negative correlation between percentage of stained sperm heads and normal morphology where nonsignificant correlation was elicited regarding sperm count and sperm motility.

CONCLUSION(S)

There is a significant increase of abnormal sperm chromatin condensation in infertile men with varicocele that is markedly improved after varicocelectomy.

An assessment of new sperm tests for male infertility

The routine semen analysis, although used for more than 50 years, fails to accurately distinguish between fertile and infertile men. As a consequence, many tests of sperm function (TSF) have been developed. This review discusses both older and newer diagnostic TSF. It outlines the principles underlying each assay and reviews aggregate clinical data to determine its current relevance and utility. It concludes that the relevance of many older TSF is questionable, with the wide acceptance of intracytoplasmic sperm injection (ICSI). Newer TSF have the potential to deliver more clinically relevant information but require more extensive study to better understand their predictive role in the ICSI era.

Surgical treatment of male infertility in the era of intracytoplasmic sperm injection - new insights

Assisted reproductive technology is an evolving area, and several adjuvant procedures have been created to increase a couple's chance of conceiving. For male infertility, the current challenges are to properly accommodate old and new techniques that are both cost-effective and evidence-based. In this context, urologists are expected to diagnose, counsel, provide medical or surgical treatment whenever possible and/or correctly refer male patients for assisted conception. Urologists are sometimes part of a multiprofessional team in an assisted reproduction unit and are responsible for the above-cited tasks as well as the surgical retrieval of sperm from either the epididymides or testicles. We present a comprehensive review of the surgical treatment options for infertile males, including the perioperative planning and prognostic aspects, with an emphasis on the role of microsurgery in the optimization of treatment results. This review also discusses current techniques for sperm retrieval that are used in association with assisted reproductive technology and includes sperm retrieval success rates according to the technique and the type of azoospermia. New insights are provided with regard to each surgical treatment option in view of the availability of assisted conception to overcome male infertility.

Analysis of azoospermia factor loci polymorphisms among Tunisian infertile men with varicocele

AIMS

The preponderance of experimental data from clinical and animal models demonstrates an adverse effect of varicocele on spermatogenesis. The review of the literature shows that there may be an underlying genetic etiology in varicocele. Here, we explore the Yq microdeletions among infertile men to evaluate their involvement in varicocele development and sperm production defect.

RESULTS

Microdeletions of 14 sequence-tagged-sites in the Yq11 region were screened in 210 infertile men using polymerase chain reaction techniques. Out of 210 infertile men, 69 (33%) men were with varicocele. Our results showed that the risk to develop varicocele is increased among infertile men with spermatogenesis (oligo-normospermia) (odds ratio = 3.57, confidence interval 95%: 1.49-8.84). However, we did not find any relationship between Y chromosome microdeletions and varicocele appearance (p = 0.73). In addition, a significant association was found between Y microdeletions and oligospermia (p < 10(-8)) or azoospermia (p < 10(-8)) using patients with normospermic characteristics as a control.

CONCLUSION

Our work showed the absence of relationship between Y chromosome microdeletions and varicocele development and the association of the two factors, independently, with sperm production defect.

Varicocele and nutcracker syndrome: sonographic findings

OBJECTIVE

Varicocele is a vascular lesion commonly associated with infertility. Its etiology is only partly understood; hence, the purpose of the study was to establish its correlation with intrinsic anatomic differences and nutcracker syndrome.

METHODS

A total of 93 patients with varicocele and 76 patients without varicocele were enrolled. The diagnosis of varicocele was based on physical examination, followed by sonographic evaluation of the hilar portion and aortomesenteric portion (AMP) of the left renal vein (LRV). The anteroposterior diameter in millimeters and peak flow in centimeters per second in each region were measured.

RESULTS

A total of 28 patients with the nutcracker syndrome were identified in the study group (30.10%), and 2 were identified in the control group (2.63%). The mean diameters of the hilar portion and AMP of the LRV were significantly different in varicocele-affected patients compared with the control group (P < .0001 for both). The mean peak velocities in the hilar portion and AMP were significantly different in patients with varicocele (P < .0001). Patients with varicocele and nutcracker syndrome did not have a significant difference in either the hilar or AMP diameter compared with patients with varicocele without nutcracker syndrome. They had a significant difference in both the hilar and AMP peak flow velocity (P = .0001 for both).

CONCLUSIONS

Our findings indicate that nutcracker syndrome is a frequent finding in varicocele-affected patients and should be routinely excluded as a possible cause of varicocele. In addition, intrinsic anatomic differences in the AMP and hilar portion of the LRV could be directly responsible for the onset of varicocele.

Semen analysis in 21st century medicine: the need for sperm function testing

Sperm function testing, once commonly performed for the infertile couple before employing assisted reproductive technology (ART), has fallen out of favour in many reproductive medicine centers throughout the world. Indeed, the most recent addition of the 'World Health Organisation (WHO) Laboratory Manual for the Examination and Processing of Human Semen' now groups many of these procedures into a section termed Research Procedures. In large part, this reflects the current clinical practice of bypassing the in-depth evaluation of the male partner, while assuming that if a spermatozoon can be found for intracytoplasmic sperm injection (ICSI), it must be a healthy cell capable of achieving fertilization. Nevertheless, sperm function testing can provide valuable clinical insights into defects causing male infertility. Admittedly, in some cases, functional sperm deficiencies can be overcome using an ART. In other cases, couples will be empowered by the knowledge of the cause of their infertility, and for some couples, perhaps even the likelihood of ICSI success (relative to the spermatozoa). The knowledge allows them to make truly informed reproductive decisions, including (perhaps) the decision to seek donor insemination, to adopt or to remain childless. Knowledge of the cause of their infertility may provide closure for couples and a sense of confidence regarding their choice of reproductive treatment.

Sperm DNA: organization, protection and vulnerability: from basic science to clinical applications--a position report

This article reports the results of the most recent in a series of EHSRE workshops designed to synthesize the current state of the field in Andrology and provide recommendations for future work (for details see Appendix). Its focus is on methods for detecting sperm DNA damage and potential application of new knowledge about sperm chromatin organization, vulnerability and repair to improve the diagnosis and treatment of clinical infertility associated with that damage. Equally important is the use and reliability of these tests to identify the extent to which environmental contaminants or pharmaceutical agents may contribute to the incidence of sperm DNA damage and male fertility problems. A working group (for workshop details, see Appendix) under the auspices of ESHRE met in May 2009 to assess the current knowledgebase and suggest future basic and clinical research directions. This document presents a synthesis of the working group's understanding of the recent literature and collective discussions on the current state of knowledge of sperm chromatin structure and function during fertilization. It highlights the biological, assay and clinical uncertainties that require further research and ends with a series of 5 key recommendations.

Decreased sperm DNA fragmentation after surgical varicocelectomy is associated with increased pregnancy rate

PURPOSE

We prospectively evaluated changes in sperm chromatin structure in infertile patients before and after surgical repair of varicocele, and the impact on the pregnancy rate.

MATERIALS AND METHODS

Included in the study were 49 men with at least a 1-year history of infertility, a palpable varicocele and oligospermia. World Health Organization semen analysis and sperm DNA damage expressed as the DNA fragmentation index using the sperm chromatin structure assay were assessed preoperatively and postoperatively. Pregnancy (spontaneous and after assisted reproductive technique) was recorded 2 years after surgery.

RESULTS

Mean sperm count, sperm concentration and sperm progressive motility improved significantly after varicocelectomy from 18.3 x 10(6) to 44.4 x 10(6), 4.8 x 10(6)/ml to 14.3 x 10(6)/ml and 16.7% to 26.6%, respectively (p <0.001). The DNA fragmentation index decreased significantly after surgery from 35.2% to 30.2% (p = 0.019). When the definition of greater than 50% improvement in sperm concentration after varicocelectomy was applied, 31 of 49 patients (63%) responded to varicocelectomy. After varicocelectomy 37% of the couples conceived spontaneously and 24% achieved pregnancy with assisted reproductive technique. The mean postoperative DNA fragmentation index was significantly higher in couples who did not conceive spontaneously or with assisted reproductive technique (p = 0.033).

CONCLUSIONS

After varicocelectomy sperm parameters significantly improved and sperm DNA fragmentation was significantly decreased. Low DNA fragmentation index values are associated with a higher pregnancy rate (spontaneous and with assisted reproductive technique). We suggest that varicocelectomy should be considered in infertile men with palpable varicocele, abnormal semen analysis and no major female factors.

Advances in the management of male infertility

Male infertility can be treated by surgical procedures (e.g., varicocelectomy) or by administration of drugs if causal factors (e.g., seminal tract infections) are detected. In more severe cases, methods of assisted fertilization often have to be applied, but even these have only a limited success rate. Recent studies have demonstrated that disturbances of sperm DNA integrity (determined by the acridine orange test) can explain certain cases of fertilization failure and failure to achieve pregnancy following in vitro fertilisation with intracytoplasmic sperm injection. The evaluation of DNA integrity should be considered when diagnosing male infertility as it has been shown to be an independent factor and can be used as a supplement to standard semen analysis. Analysis of DNA integrity may, therefore, provide further information about altered male fertility and lead to administration of more appropriate therapy.

Antioxidants and sperm DNA damage: a clinical perspective

PURPOSE

Infertile men possess substantially more sperm DNA damage than do fertile men, damage that may impact negatively on reproductive outcomes. In this era of assisted reproductive technologies there is mounting concern regarding the safety of utilizing DNA-damaged spermatozoa in this setting. Therefore, it is important to identify strategies that may reduce sperm DNA damage. The purpose of this review is to discuss the rationale for antioxidant therapy in men with sperm DNA damage and to evaluate the data on the efficacy of dietary and in vitro antioxidant preparations on sperm DNA damage.

METHODS

We reviewed the literature on antioxidants and sperm DNA damage.

RESULTS

To date, the data suggest that dietary antioxidants may be beneficial in reducing sperm DNA damage, particularly, in men with high levels of DNA fragmentation. However, the mechanism of action of dietary antioxidants has not been established and most of the clinical studies are small. A beneficial effect of in vitro antioxidant supplements in protecting sperm DNA from exogenous oxidants has been demonstrated, however, the effect of these antioxidants in protecting sperm from endogenous ROS, gentle sperm processing and cryopreservation has not been established.

Cause-specific treatment in patients with high sperm DNA damage resulted in significant DNA improvement

Assessment of sperm DNA damage has been suggested as a negative predictor of fertility potential. Multiple pathological factors acting at both the intra-testicular and post-testicular levels may contribute to sperm DNA damage. The relative contribution of each of these factors in an individual with high DNA damage (>30%) is unclear. The management of patients with elevated DNA damage is also challenging. The purpose of our retrospective study was to evaluate the clinical course of patients with sperm DNA damage over 30% and to assess the effect of non-specific (oral antioxidant) and cause-specific treatments on the quality of their sperm DNA. Results of our retrospective study suggest that the evaluated group with high DNA damage was diagnostically heterogeneous and comprised patients with varicoceles, bacteriospermia and idiopathic infertility. A three month course of antioxidant therapy reduced sperm DNA damage in only 30/61 (49%) patients with significant improvement between the initial and post-treatment DNA Fragmentation Index (DFI) results (46.8%+/-14.1 vs. 36.7%+/-16.6, p < .001). The positive effect of antioxidants could be age-dependent, as patients older that 40 years of age showed no improvement after such treatment. The cause-specific treatments showed superior results compared to antioxidants alone. Improvement was observed in 7/9 (78%) of patients after surgical varicocele repair between the initial and post-treatment DFI results (44.7%+/-12.8 vs. 28.4%+/-9.5, p < .03). The majority of the patients 13/14 (93%) with bacteriospermia had improvement in sperm DFI results after antibiotic treatment (50.4%+/-19.1 vs. 38.6%+/-18.7, p < .001).

Male gamete survival at stake: causes and solutions

Over the years, the development of assisted reproductive technology to bypass male factor infertility has improved drastically. Considered one of the most perplexing disorders in the reproductive field, male factor infertility is prevalent and may be on the rise. Unfortunately, its aetiology remains elusive. One of the main reasons lies in the complex machinery and structure of the hydrodynamic sperm cell. Its polyunsaturated fatty acid cell membrane, the protamines in its genetic material and the absence of antioxidants in its cytoplasm ensure that the spermatozoon is highly susceptible to environmental effects. The spermatozoon's genesis, storage, and transport through the male reproductive tract are also susceptible, genetically and pathologically, to environmental effects. This review aims to include all the possible causes of disruption to this unique cell and their probable solutions, in the hope of clearing up the ambiguity that surrounds male factor infertility.

Role of antioxidants in the treatment of male infertility

Male infertility continues to be a clinical challenge of increasing significance. While male factors such as decreased semen quality are responsible for 25% of all infertility issues, the etiology of suboptimal semen quality is poorly understood. Many physiological, environmental, and genetic factors have been implicated, including oxidative stress. Oxidative stress is induced by reactive oxygen species (ROS), or free radicals, and although ROS are required for critical aspects of sperm function, excessive levels of ROS can negatively impact sperm quality. The origin of ROS generation, and the etiologies of increased ROS in men with suboptimal sperm quality have only recently been elucidated, offering multiple targets for potential therapy. Here, we present a critical review of the literature describing the role of oxidative stress on decreased sperm function, as well as the role of antioxidants in the treatment of male factor infertility.

The clinical utility of sperm DNA integrity testing

Sperm DNA damage is more common in infertile men and may contribute to poor reproductive performance. However, current methods for evaluating sperm DNA integrity do not reliably predict treatment outcomes, and no treatment for abnormal DNA integrity has proven clinical value.

The role of varicocele repair in the new era of assisted reproductive technology

Infertility affects 10-15% of couples who are trying to conceive, and half of the cases are due to male infertility. Intracytoplasmic sperm injection is increasingly being used to overcome multiple sperm deficiencies. Due to its effectiveness, some have proposed ICSI as a solution for all cases of male infertility, regardless of the cause. Hence, even men with potentially treatable causes of infertility have sought the aid of assisted reproductive technology, rather than undergo specific therapies to treat their infertility. Varicoceles are the most frequent physical finding in infertile men; indeed, they may be responsible for nearly one-third of cases of male infertility. Varicocele management, however, has always been a controversial issue because very few randomized, controlled studies have been performed to examine varicocelectomy as an infertility treatment. Significant evidence suggests that varicoceles have a harmful effect on the testis and that varicocelectomy can not only prevent progressive decline in testicular function but also reverse the damage. However, the degree to which varicocele repair improves pregnancy rates and the success of assisted reproductive technology remains controversial.

Oxidative stress and male infertility--a clinical perspective

Oxidative stress occurs when the production of potentially destructive reactive oxygen species (ROS) exceeds the bodies own natural antioxidant defenses, resulting in cellular damage. Oxidative stress is a common pathology seen in approximately half of all infertile men. ROS, defined as including oxygen ions, free radicals and peroxides are generated by sperm and seminal leukocytes within semen and produce infertility by two key mechanisms. First, they damage the sperm membrane, decreasing sperm motility and its ability to fuse with the oocyte. Second, ROS can alter the sperm DNA, resulting in the passage of defective paternal DNA on to the conceptus. This review will provide an overview of oxidative biochemistry related to sperm health and will identify which men are most at risk of oxidative infertility. Finally, the review will outline methods available for diagnosing oxidative stress and the various treatments available.

Sperm nuclear DNA fragmentation and mitochondrial activity in men with varicocele

OBJECTIVE

To verify the impact of varicocele on semen quality and sperm function (DNA integrity and mitochondrial activity).

DESIGN

Prospective study.

SETTING

Patients in an academic research environment.

PATIENT(S)

Seventeen patients with a clinical diagnosed varicocele of grade II or III and 20 men without a varicocele.

MAIN OUTCOME MEASURE(S)

Rate of sperm DNA fragmentation as assessed by the Comet assay and categorized as classes I (no DNA fragmentation), II (little DNA fragmentation), III (meaningful DNA fragmentation), and IV (high DNA fragmentation). Rate of mitochondrial activity as assessed by the diaminobenzidine (DAB) assay and categorized as grades I (all mitochondria active), II (most mitochondria active), III (most mitochondria inactive), and IV (all mitochondria inactive).

RESULT(S)

No statistically significant differences were found between the study and control groups with respect to age, ejaculatory abstinence, and round cell count. Men with varicocele had significantly higher ejaculate volume, concentration of immotile sperm, and neutrophil count and lower mean percentage of sperm concentration, progressive motility, and morphology than men in the control group. The study group presented a lower percentage of sperm with little DNA fragmentation (class II) and a higher percentage of sperm with DNA fragmentation (class IV). In addition, the study group presented a greater percentage of sperm with inactive mitochondria (class III).

CONCLUSION(S)

Compared with men without varicocele, men with varicocele had a higher percentage of cells with DNA fragmentation and sperm with inactive mitochondria. Indeed, varicocele causes a decrease in motility, concentration, and morphology and an increase in volume and concentration of immotile sperm and neutrophils. The sperm functional evaluation (DNA fragmentation and mitochondrial activity) could be important factors in deciding treatment options for men with varicocele.

Attenuation of oxidative stress after varicocelectomy in subfertile patients with varicocele

PURPOSE

We examined changes due to oxidative damage to spermatozoa and alterations in antioxidant capacity in subfertile patients with varicocele before and after varicocelectomy in a prospective study.

MATERIALS AND METHODS

A total of 30 young subfertile male patients with varicocele were recruited in this study. Varicocele was diagnosed by physical examination and Doppler ultrasound. Semen analysis was performed in the 30 patients before and 6 months after varicocelectomy using a computer assisted semen analyzer. The parameters for evaluating oxidative stress changes were 4977 bp deletion of mitochondrial DNA in sperm, as detected by polymerase chain reaction, the 8-OHdG (8-hydroxy-2'-deoxyguanosine) content in spermatozoa DNA, as measured by a high performance liquid chromatography electrochemical method, and seminal plasma protein thiols and ascorbic acid, as measured by spectrophotometric methods.

RESULTS

Semen quality, including motility, morphology and sperm density, was improved in 22 patients (73.3%) after varicocelectomy. The incidence of 4977 bp deletion of mitochondrial DNA in sperm was 40% (12 of 30 patients) and 13.3% (4 of 30) before and after surgery, respectively. Mean +/- SD 8-OHdG content in sperm DNA, and seminal plasma protein thiols and ascorbic acid were 10.27 +/- 2.24/10(5) 2'-deoxyguanosine, 0.77 +/- 0.75 nmole/ml and 1.87 +/- 0.40 mg/dl before operation, and 5.95 +/- 1.46/10(5) 2'-deoxyguanosine, 3.00 +/- 1.17 nmole/ml and 3.12 +/- 0.94 mg/dl after surgery, respectively. The incidence of 4977 bp deletion of mitochondrial DNA in sperm and the level of 8-OHdG in sperm DNA were decreased, and seminal plasma protein thiols and ascorbic acid were increased significantly in all 30 patients after varicocelectomy. Also, in the 8 patients in whom semen quality did not improve after surgery a significant decrease in 8-OHdG in sperm DNA, and a significant increase in seminal plasma protein thiols and ascorbic acid were observed.

CONCLUSIONS

Subfertile patients with varicocele had a significant decrease in oxidative damage in sperm DNA and an increase in antioxidant capacity in seminal plasma after varicocelectomy, indicating that surgery is effective treatment in such patients.

Impact of clinical varicocele and testis size on seminal reactive oxygen species levels in a fertile population: a prospective controlled study

OBJECTIVE

To investigate: 1) the impact of clinical varicocele on reactive oxygen species (ROS) levels in neat and washed semen in a proven fertile population; and 2) the correlation between ROS levels, testicular volume, and varicocele grade in the same population of fertile men.

DESIGN

Prospective controlled clinical study.

SETTING

Andrology laboratory at tertiary-care hospital.

PATIENT(S)

One hundred fourteen healthy fertile men (81 normal fertile and 33 fertile with clinical varicocele) and 30 infertile patients (control subjects).

INTERVENTION(S)

Standard semen analysis and measurement of sperm ROS production.

MAIN OUTCOME MEASURE(S)

Seminal parameters, seminal ROS levels, seminal leukocyte levels, clinical varicocele, and testis size.

RESULT(S)

Thirty-three of the 114 (29%) fertile men had clinical varicocele (grade 1, n = 14; grade 2, n = 11; and grade 3, n = 8), and the remaining 81 (71%) had a normal physical examination. Levels of ROS and semen quality did not differ significantly between the fertile men with or without varicocele. No significant differences in ROS levels in neat and washed semen were observed compared with fertile men with grades 2 and 3 varicocele and with fertile men with varicocele grade 1. The ROS levels in neat and washed semen were not significantly correlated with varicocele grade in fertile men. No significant correlations between ROS levels and testis volume were observed between the fertile groups.

CONCLUSION(S)

The presence of clinical varicocele in fertile men is not associated with higher seminal ROS levels or abnormal semen parameters. Levels of ROS are not correlated with varicocele grade or testis volume in the same population of fertile men.

The role of heat shock protein 70 (Hsp 70) in male infertility: is it a line of defense against sperm DNA fragmentation?

OBJECTIVE

To clarify the role of heat shock protein 70 (Hsp 70) and its relation with DNA damage in male infertility.

DESIGN

Prospective study.

SETTING

Andrology laboratory of Istanbul Medical Faculty.

PATIENT(S)

Semen samples from 37 infertile men and 13 fertile men (as controls).

INTERVENTION(S)

The percentage of DNA fragmentation was assayed with the use of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Sperm Hsp 70 expression was determined by using Western blot analysis.

MAIN OUTCOME MEASURE(S)

Both the percentages of sperm DNA fragmentation and Hsp 70 expression were correlated with semen analysis parameters.

RESULTS

TUNEL-positive spermatozoa in the infertile group (18.7% for asthenospermics and 13.0% for oligoasthenospermics) were higher than the fertile group (4.9%). Significant inverse correlations were detected between percentage of TUNEL-positive cells and both concentration (r = -0.487) and motility (r = -0.377) of spermatozoa. No expression of Hsp 70 was observed in azospermic group, whereas Hsp 70 levels were found increased significantly in infertile group (U = 62 for asthenospermics and U = 38 for oligoasthenospermics) compared to fertile group as analyzed by using Mann-Whitney U Wilcoxon rank sum test. Furthermore, significant positive correlation was found between percentage of TUNEL-positive cells and Hsp 70 expression (r = 0.357).

CONCLUSION(S)

Hsp 70 expression may have been increased as a protective mechanism against apoptosis in spermatozoa of infertile men.

Efficacy of Varicocelectomy in Improving Semen Parameters: New Meta-analytical Approach

OBJECTIVES

To determine the efficacy of varicocelectomy in improving semen parameters.

METHODS

A meta-analysis was performed to evaluate both randomized controlled trials and observational studies using a new scoring system. This scoring system was developed to adjust and quantify for various potential sources of bias, including selection bias, follow-up bias, confounding bias, information or detection bias, and other types of bias, such as misclassification. Of 136 studies identified through the electronic and hand search of references, only 17 studies met our inclusion criteria. The study population was infertile men with clinically palpable unilateral or bilateral varicocele and at least one abnormal semen parameter who had undergone surgical varicocelectomy (high ligation or inguinal microsurgery). Only those studies that had at least three semen analyses (ie, sperm count, motility, and morphology) per patient, before and after surgical varicocelectomy, were included.

RESULTS

The combined analysis demonstrated that the sperm concentration increased by 9.71 x 10(6)/mL (95% confidence interval [CI] 7.34 to 12.08, P <0.00001) and motility increased by 9.92% (95% CI 4.90 to 14.95, P = 0.0001) after microsurgical varicocelectomy. Similarly, the sperm concentration increased by 12.03 x 10(6)/mL (95% CI 5.71 to 18.35, P = 0.0002) and motility increased by 11.72% (95% CI 4.33 to 19.12, P = 0.002) after high ligation varicocelectomy. The improvement in World Health Organization sperm morphology was 3.16% (95% CI 0.72 to 5.60, P = 0.01) after both microsurgery and high ligation varicocelectomy.

CONCLUSIONS

Surgical varicocelectomy significantly improves semen parameters in infertile men with palpable varicocele and abnormal semen parameters.

Spermatozoal sensitive biomarkers to defective protaminosis and fragmented DNA

Human sperm DNA damage may have adverse effects on reproductive outcome. Infertile men possess substantially more spermatozoa with damaged DNA compared to fertile donors. Although the extent of this abnormality is closely related to sperm function, the underlying etiology of ensuing male infertility is still largely controversial. Both intra-testicular and post-testicular events have been postulated and different mechanisms have been proposed to explain the presence of damaged DNA in human spermatozoa. Three among them, i.e. abnormal chromatin packaging, oxidative stress and apoptosis, are the most studied and discussed in the present review. Furthermore, results from numerous investigations are presented, including our own findings on these pathological conditions, as well as the techniques applied for their evaluation. The crucial points of each methodology on the successful detection of DNA damage and their validity on the appraisal of infertile patients are also discussed. Along with the conventional parameters examined in the standard semen analysis, evaluation of damaged sperm DNA seems to complement the investigation of factors affecting male fertility and may prove an efficient diagnostic tool in the prediction of pregnancy outcome.