Prospective study of leukocytes and leukocyte subpopulations in semen suggests they are not a cause of male infertility

Leukocytospermia and/or Bacteriospermia: Impact on Male Infertility

Infertility is a globally underestimated public health concern affecting almost 190 million people, i.e., about 17.5% of people during their lifetime, while the prevalence of male factor infertility is about 7%. Among numerous other causes, the prevalence of male genital tract infections reportedly ranges between 10% and 35%. Leukocytospermia is found in 30% of infertile men and up to 20% in fertile men. Bacterial infections cause an inflammatory response attracting leukocytes, which produce reactive oxygen species (ROS) and release cytokines, both of which can cause damage to sperm, rendering them dysfunctional. Although leukocytospermia and bacteriospermia are both clinical conditions that can negatively affect male fertility, there is still debate about their impact on assisted reproduction outcomes and management. According to World Health Organization (WHO) guidelines, leukocytes should be determined by means of the Endtz test or with monoclonal antibodies against CD15, CD68 or CD22. The cut-off value proposed by the WHO is 1 × 106 peroxidase-positive cells/mL. For bacteria, Gram staining and semen culture are regarded as the "gold standard", while modern techniques such as PCR and next-generation sequencing (NGS) are allowing clinicians to detect a wider range of pathogens. Whereas the WHO manual does not specify a specific value as a cut-off for bacterial contamination, several studies consider semen samples with more than 103 colony-forming units (cfu)/mL as bacteriospermic. The pathogenic mechanisms leading to sperm dysfunction include direct interaction of bacteria with the male germ cells, bacterial release of spermatotoxic substances, induction of pro-inflammatory cytokines and ROS, all of which lead to oxidative stress. Clinically, bacterial infections, including "silent" infections, are treatable, with antibiotics being the treatment of choice. Yet, non-steroidal antiphlogistics or antioxidants should also be considered to alleviate inflammatory lesions and improve semen quality. In an assisted reproduction set up, sperm separation techniques significantly reduce the bacterial load in the semen. Nonetheless, contamination of the semen sample with skin commensals should be prevented by applying relevant hygiene techniques. In patients where leukocytospermia is detected, the causes (e.g. infection, inflammation, varicocele, smoking, etc.) of the leukocyte infiltration have to be identified and addressed with antibiotics, anti-inflammatories or antioxidants in cases where high oxidative stress levels are detected. However, no specific strategy is available for the management of leukocytospermia. Therefore, the relationship between bacteriospermia and leukocytospermia as well as their specific impact on functional sperm parameters and reproductive outcome variables such as fertilization or clinical pregnancy must be further investigated. The aim of this narrative review is to provide an update on the current knowledge on leukocytospermia and bacteriospermia and their impact on male fertility.

Effect of leukocytes on semen quality in men from primary and secondary infertile couples: A cross-sectional study

Background and Aims

Leukocytospermia (LCS) is a known cause of male infertility. However, the relationship between seminal leukocytes and semen quality among infertile couples remains controversial. This study aims to investigate the association between semen quality and LCS in male partners of infertile couples.

Methods

Semen samples were collected from 512 men who asked for a fertility evaluation in a reproductive center in China. Seminal leukocytes were counted following peroxidase staining with benzidine. Other semen parameters were compared in subfertile men with and without LCS.

Results

Poor semen quality (e.g., low semen volume, sperm concentration, and sperm progressive/total motility) was observed among men with LCS compared to those without LCS. Men with LCS had a higher risk of low sperm progressive motility (OR = 0.99, 95% CI = 0.98-0.99, p = 0.02) and total motility (OR = 0.99, 95% CI = 0.98-0.99, p = 0.02), even after adjustment for potential confounders (both OR = 0.99, 95% CI = 0.98-0.99, p = 0.03). Lower sperm viability was observed in LCS from male partners of secondary couples, while no significant difference in semen parameters was found between men with and without LCS in male partners of primary infertile couples. Low sperm motility and viability were associated with LCS in men from secondary infertile couples after adjusting for confounders (OR = 0.97, 95% CI = 0.95-0.99, p = 0.04; OR = 0.94, 95% CI = 0.89-0.99, p = 0.04, respectively).

Conclusions

Our findings indicate that a higher risk of abnormal semen parameters was correlated with an increased number of leukocytes in men from secondary infertile couples.

Cell-type-specific determination of reactive oxygen species by flow cytometry

BACKGROUND

Seminal leukocyte-generated reactive oxygen species may have a significant impact on sperm intracellular reactive oxygen species levels, therefore contributing to oxidative damage and consequent functional impairment of spermatozoa. This relationship may be utilized for male urogenital inflammation-driven oxidative stress diagnostics.

OBJECTIVE

To obtain seminal cell-specific, reactive oxygen species-related fluorescence intensity cut-off values to differentiate leukocytospermic samples displaying reactive oxygen species overproduction (oxidative burst) from normozoospermic seminal samples.

MATERIAL AND METHODS

Ejaculates gained by masturbation were obtained from patients in the framework of andrology consultations. The results published in this paper were generated from samples for which the attending physician requested spermatograms and seminal reactive oxygen species laboratory tests. Routine seminal analyses were performed according to World Health Organization guidelines. Samples were divided into normozoospermic "non-inflamed," and leukocytospermic groups. The semen was stained by 2',7'-dichlorodihydrofluorescein diacetate and the reactive oxygen species-related fluorescence signal and the percentage of reactive oxygen species-positive spermatozoa within the living population were quantified by flow cytometry.

RESULTS

Reactive oxygen species-related mean fluorescence intensity was higher in both spermatozoa and leukocytes from leukocytospermic samples than in those from normozoospermic samples. Mean fluorescence intensity in spermatozoa was positively and linearly correlated with mean fluorescence intensity measured in leukocytes in both groups.

DISCUSSION

The capacity of spermatozoa to generate reactive oxygen species is at least three log lower than that of granulocytes. The question is whether the reactive oxygen species-producing machinery of spermatozoa is capable of causing autologous oxidative stress or whether leukocytes are the predominant source of seminal oxidative stress. Based on our observations, the reactive oxygen species production of leukocytes may have a significant impact on the overall reactive oxygen species levels measured in spermatozoa.

CONCLUSION

Reactive oxygen species-overproducing leukocytospermic and normozoospermic seminal samples can reliably be differentiated based on reactive oxygen species mean fluorescence intensity measurement.

Evaluation and management of male genital tract infections in the setting of male infertility: an updated review

PURPOSE OF REVIEW

Male infertility may be secondary to male genital tract infection (MGTI) in an estimated 15% of cases. In the absence of overt clinical signs, evaluation for MGTI beyond semen analysis is not well established. Therefore, we review the literature on the evaluation and management of MGTI in the setting of male infertility.

RECENT FINDINGS

A set of international guidelines recommends semen culture and PCR testing, but the significance of positive results remains unclear. Clinical trials evaluating anti-inflammatory or antibiotic treatment report improvements in sperm parameters and leukocytospermia, but data on the effect on conception rates are lacking. Human papillomavirus (HPV) and the novel coronavirus (SARS-CoV-2) have been associated with poor semen parameters and decreased conception rates.

SUMMARY

The finding of leukocytospermia on semen analysis prompts further evaluation for MGTI, including focused physical examination. The role of routine semen culture is controversial. Treatment options include anti-inflammatories; frequent ejaculation; and antibiotics, which should not be used in the absence of symptoms or microbiological infection. SARS-CoV-2 represents a subacute threat to fertility that should be screened for in the reproductive history along with HPV and other viruses.

Round Cells in Diagnostic Semen Analysis: A Guide for Laboratories and Clinicians

Round cells in seminal fluid are defined as either leucocytes or immature germ cells. Laboratories undertaking semen analysis often report these combined as a concentration, with no further review, comment or direction for clinician action or review. Although numerous publications discuss the possible clinical relevance of these cells (particularly leucocytes) in infertility, the methods employed to differentiate them are often beyond the scope of most diagnostic laboratories. This paper aims to support healthcare scientists in understanding the clinical significance of round cells and aid their identification, differentiation and interpretation. This will support the quality of care the patient receives and direct clinicians to further considerations that may be appropriate for their patient and should consequently reduce indiscriminate and unnecessary use of antibiotics.

Deciphering the Nexus Between Oxidative Stress and Spermatogenesis: A Compendious Overview

Oxidative stress (OS) and reactive oxygen species (ROS) are one of the main reasons for the multifactorial concern - male infertility. ROS are active components of cellular metabolism that are intrinsic to cellular functioning and are present at minimal and unreactive levels in normal cells. They are an integral component of the sperm developmental physiology, capacitation, and function. As said "anything in excess is poison," so is the case with ROS. These, when produced in excess to the antioxidants present in the seminal plasma, cause multiple malformations during the process of spermatogenesis such as lipid peroxidation, interfere with capacitation, sperm DNA fragmentation and damage to the membrane of the sperm which in turn reduces the motility of the sperm and its ability to fuse with the oocyte. Exposure of spermatozoa to oxidative stress is a major causative agent of male infertility. Thus, a delicate balance between the beneficial and detrimental effects of ROS for proper functions is of utter importance. In this chapter, the influence of ROS in OS which is a key player in male infertility along with the diagnosis, available treatment, and prevention of extensive ROS buildup within the spermatozoa are highlighted.

Reactive Oxygen Species Secreted by Leukocytes in Semen Induce Self-Expression of Interleukin-6 and Affect Sperm Quality

Reproductive tract inflammation is considered an important cause of male infertility. Increased leukocytes in semen can produce many reactive oxygen species (ROS), which affect sperm function. The aim of this study is to identify the main source of ROS in seminal plasma and to assess the effect of ROS on leukocytes. Semen samples (n = 20) with leukocyte concentration >1 × 10⁶ were collected from a male infertility clinic. This study mainly compares the sperm function parameters of the normal group and the semen white blood cell group >1 × 10⁶. The results identified that ROS in semen was closely related to sperm function parameters, and CD45⁺ leucocytes were the main source of ROS. Compared with the control group, the concentration of IL-2, IL-4, IL-6, IFN-γ, and TNF-α was higher in the experimental group. Leukocytes in semen may regulate the secretion of ROS through the mammalian target of rapamycin (mTOR) pathway. A considerable amount of ROS can upregulate the expression of IL-6 in leukocytes via the nuclear factor kappa-B (NF-kB) pathway.

The role of infections and leukocytes in male infertility

Declining birth rates are one of the problems facing society today. Male counterparts are responsible for about half of the infertility cases, and genitourinary tract infections may play a contributing role in approximately 15% of male infertility cases. Leukocytospermia is an established indicator of infection in the male urogenital tract, although other microorganisms such as bacteria and virus may also be contributors to the etiology of male infertility. The pathophysiology of these infectious agents may be initiated by a local inflammatory reaction resulting in an increase in reactive oxygen species (ROS). This results in testicular injury, thereby affecting sperm morphology, sperm motility, sperm viability and elevation of the seminal leukocyte as a result of the genital tract infection. The infectious and inflammatory changes can result in male infertility. It is proposed that high concentrations of seminal leukocyte and infectious agents may affect sperm function resulting in clumping of motile spermatozoa, decreasing acrosomal functionality and also causing alterations in sperm morphology. However, the literature has poorly clarified the role of infection in male infertility, provoking further debate and research on this topic.

Time to re-evaluate the guidance on sexual infections in fertility services

Current guidance in the UK for fertility services on the screening for sexually transmitted infections (STI) is solely directed towards Chlamydia trachomatis. Evidence used to formulate the guidance is based on research undertaken before more sensitive diagnostic methods were available and before testing of some organisms was even possible. This commentary outlines current STI trends, evidence available for STI effect on fertility and new diagnostic methods of screening. It aims to demonstrate that UK guidance should be updated and directed towards areas where further research is required.

Relationship between leukocytospermia, reproductive potential after assisted reproductive technology, and sperm parameters: a systematic review and meta-analysis of case-control studies

BACKGROUND

The association of leukocytospermia with male fertility is still under debate.

OBJECTIVE

To evaluate the impact of leukocytospermia (≥1 × 10⁶  white blood cells/mL of semen, according to the World Health Organization) in men attending a fertility clinic for couple subfertility, on fertility outcomes after assisted reproductive technology (ART) and on semen quality.

MATERIALS AND METHODS

A systematic review with meta-analysis of case-control studies reporting mean ± standard deviation for values of different seminal parameters (sperm concentration, progressive motility, sperm morphology, sperm DNA fragmentation, semen volume, and Ph) and fertilization rate (FR), or the odds ratio (OR) for clinical pregnancy rate (PR) per cycle after ART in leukocytospermic and non-leukocytospermic patients was performed. A literature search was carried out in MEDLINE and SCOPUS for English-language studies published till June 2018.

RESULTS

Twenty-eight case-controlled retrospective studies met the inclusion criteria, comparing fertility outcomes after ART or semen parameters in men with or without leukocytospermia. FR and PR after ART were not significantly different in the two groups. Leukocytospermic samples showed a lower sperm concentration (pooled SMD = -0.14; 95% CI: -0.28, -0.01, I²  = 71%, p_{for heterogeneity}  < 0.00001) and a lower progressive motility (pooled SMD = -0.18; 95% CI: -0.29, -0.06; I²  = 59%, p_{for heterogeneity}  < 0.0001). However, the significant differences disappeared, along with the large inter-study heterogeneity, when analyses were restricted to studies clearly reporting the inclusion of men without clinical evidence of seminal tract infection.

DISCUSSION AND CONCLUSION

Leukocytospermia in men seeking consultation for couple subfertility is not associated with a reduced fertility after ART and with altered semen quality in populations asymptomatic for genital tract infection. Therefore, the current clinical criteria for definition of leukocytospermia should be re-assessed in subfertile couples attending a fertility clinic.

Oxidation reduction potential: a new biomarker of male infertility

Oxidative stress is considered a major etiology for male infertility, more specifically idiopathic infertility. The causes of seminal oxidative stress can be intrinsic, such as varicocele or due to the presence of active leukocytes and immature germ cells. Reported external causes are smoking, alcohol or exposure to environmental toxins. Traditional methods to determine the seminal oxidative stress do not evaluate this status directly, but rather measure its components or intermediate products indirectly, instead. The major disadvantages of the traditional methods are related with time and cost as these methods are extremely time consuming and require expensive equipment, consumables and highly skilled laboratory personnel. To overcome these drawbacks, the MiOXSYS® system, a method which directly measures the oxidation-reduction potential (ORP), was developed. The evaluation of the ORP using MiOXSYS® is cost-effective, easy and quick. However, this newly introduced method to evaluate the oxidative status of semen still requires validation in different andrology laboratory settings across the world.

Review of Guidelines for the Evaluation and Treatment of Leukocytospermia in Male Infertility

Leukocytospermia is an ill-defined and poorly understood condition affecting up to 30% of male factor infertility. Current guidelines on leukocytospermia vary significantly, although it has been linked to increased rates of infertility, uncertainty about its clinical significance, diagnosis, and treatment remains. The guidelines are conflicting with sparse data scattered across different specialties and continents. This study aims to compare and contrast available international guidelines and recommendations. In addition to these guidelines, we sought to consolidate the findings of trials over the last several decades. English language articles on human observational studies, retrospective, prospective, clinical trials and randomized control trials were searched for using the following terms: "leukocytospermia, pyospermia, and male infertility." Articles about treatment and management of leukocytospermia that were published between January 2010 and April 2018 were included, as well as four articles referenced in best practice and guideline statements from urological and andrological associations. Disagreements on this topic are highlighted as some guidelines describe no correlation between leukocytospermia and infertility while others show that treatment leads to improvement of sperm quality by many measures including improved pregnancy rate. Various treatments have been suggested including antibiotics, anti-inflammatory medications, and frequent ejaculation. There is a need for definitive characterization of Leukocytospermia as an infectious or inflammatory marker and a re-evaluation of the leukocyte concentration threshold. Additional studies investigating rates of conception as a measure of outcome are needed, to provide greater level of evidence and generalizability of leukocytopsermia management.

Detection of macrophages in rabbit semen and their relationship with semen quality

We aimed at the evaluating the occurrence of macrophages in rabbit semen and finding possible relationship between macrophage concentration and spermatozoa quality. The concentration of macrophages in semen samples from broiler rabbit males of lines M91 and P91 (n = 30) without overt evidence of genital tract infections was determined using monocyte/macrophage lineage antigen CD14 and flow cytometry. Then the rabbits were assigned into three groups according to the macrophage concentration in semen (MΦ1 group with less than 1 × 10⁶ macrophages/mL, MΦ2 group with 1.5-3.5 × 10⁶ macrophages/mL and MΦ3 group with more than 8 × 10⁶ macrophages/mL). Spermatozoa viability parameters such as occurrence of apoptotic (Yo-Pro-1) and dead/necrotic (propidium iodide) spermatozoa and plasma membrane integrity (PNA-Fluos) were evaluated using flow cytometry. Sperm motility parameters were determined by CASA (Computer Assisted Semen Analysis). Ultrastructural detection of macrophages was performed using transmission electron microscopy. Spermatozoa fertility potential was examined after intravaginal artificial insemination of rabbit doses. Significantly higher proportions of the apoptotic and necrotic spermatozoa and spermatozoa with lower plasma membrane integrity were revealed in the MΦ3 group compared to MΦ1 and MΦ2 groups. The percentage value of total motility and progressive movement was significantly highest in the MΦ1 group, whilst lowest in the MΦ3 group. The conception rate and the kindling rate were significantly decreased in the group with the highest macrophage concentration (MΦ3). Based on our results we can conclude that the abundance of seminal macrophages in the rabbit semen may be closely associated with poor spermatozoa quality.

An Update on Oxidative Damage to Spermatozoa and Oocytes

On the one hand, reactive oxygen species (ROS) are mandatory mediators for essential cellular functions including the function of germ cells (oocytes and spermatozoa) and thereby the fertilization process. However, the exposure of these cells to excessive levels of oxidative stress by too high levels of ROS or too low levels of antioxidative protection will render these cells dysfunctional thereby failing the fertilization process and causing couples to be infertile. Numerous causes are responsible for the delicate bodily redox system being out of balance and causing disease and infertility. Many of these causes are modifiable such as lifestyle factors like obesity, poor nutrition, heat stress, smoking, or alcohol abuse. Possible correctable measures include foremost lifestyle changes, but also supplementation with antioxidants to scavenge excessive ROS. However, this should only be done after careful examination of the patient and establishment of the individual bodily antioxidant needs. In addition, other corrective measures include sperm separation for assisted reproductive techniques. However, these techniques have to be carried out very carefully as they, if applied wrongly, bear risks of generating ROS damaging the germ cells and preventing fertilization.

Characteristics and quantities of HIV host cells in human genital tract secretions

Human immunodeficiency virus (HIV)-infected leukocytes have been detected in genital secretions from HIV-infected men and women and may play an important role in the sexual transmission of HIV. However, they have been largely overlooked in studies on mechanisms of HIV transmission and in the design and testing of HIV vaccine and microbicide candidates. This article describes the characteristics and quantities of leukocytes in male and female genital secretions under various conditions and also reviews evidence for the involvement of HIV-infected cells in both horizontal and vertical cell-associated HIV transmission. Additional research is needed in this area to better target HIV prevention strategies.

Deficient human β-defensin 1 underlies male infertility associated with poor sperm motility and genital tract infection

Genital tract infection and reduced sperm motility are considered two pivotal etiological factors for male infertility associated with leukocytospermia and asthenozoospermia, respectively. We demonstrate that the amount of human β-defensin 1 (DEFB1) in sperm from infertile men exhibiting either leukocytospermia or asthenozoospermia, both of which are associated with reduced motility and reduced bactericidal activity in sperm, is much lower compared to that in normal fertile sperm. Interference with DEFB1 function also decreases both motility and bactericidal activity in normal sperm, whereas treatment with recombinant DEFB1 markedly restores DEFB1 expression, bactericidal activity, sperm quality, and egg-penetrating ability in sperm from both asthenozoospermia and leukocytospermia patients. DEFB1 interacts with chemokine receptor type 6 (CCR6) in sperm and triggers Ca(2+) mobilization, which is important for sperm motility. Interference with CCR6 function also reduces motility and bactericidal activity of normal sperm. The present finding explains a common defect in male infertility associated with both asthenozoospermia and leukocytospermia, indicating a dual role of DEFB1 in defending male fertility. These results also suggest that the expression of DEFB1 and CCR6 may have diagnostic potential and that treatment of defective sperm with recombinant DEFB1 protein may be a feasible therapeutic approach for male infertility associated with poor sperm motility and genital tract infection.

Macrophage metalloelastase-12 is detectable in human seminal plasma and represents a predictor for inflammatory processes in the male genital tract

Macrophage metalloelastase-12 (MMP-12), a protein of the matrix metalloproteinase family, is involved in the breakdown of extracellular matrix in normal physiological processes as well as in disease processes. MMP-12 is almost exclusively produced by macrophages and is associated with inflammatory disorders. Giving the fact that inflammation negatively influences ejaculate parameters, we investigated a possible presence and correlation of MMP-12 in seminal plasma with parameters of the ejaculate, especially in leucocytospermic ejaculates. Forty-two patients who presented for semen analysis were assigned into four groups depending on the result of semen analysis according to the WHO guidelines 2010: normozoospermia (n = 11), OAT (n = 10), azoospermia (n = 10) and leucocytospermia (>1 mio. peroxidase-positive cells per ml) (n = 11). MMP-12 was detected by ELISA and was measurable in nearly all seminal plasma samples. Generally, MMP-12 concentrations were significantly higher in leucocytospermic samples than in nonleucocytospermic ones (P = 0.001). The MMP-12 levels between the latter nonleucocytospermic groups did not differ. Moreover, MMP-12 levels correlated with the presence of peroxidase-positive leucocytes. No correlation with CD 14 positive monocytes/macrophages was detected. In this study, we demonstrate that MMP-12 is present in seminal plasma and is correlated with inflammatory conditions in human semen and therefore may serve as predictor of ongoing inflammatory processes.

Human seminal fibronectin fragmentation patterns and their domain immunoreactivities in leucocytospermic patients

The aim of the work was to analyse fibronectin (FN) domain immunoreactivities and profiles of FN fragmentation in seminal plasmas of fertile normozoospermic and infertile leucocytospermic male patients. ELISA with domain-specific monoclonal antibodies and immunoblotting were used in these measurements. Immunoblotting of normal and leucocytospermic seminal plasmas revealed the presence of twelve FN bands of ~70-196kDa with nearly identical FN profiles under reducing and non-reducing conditions. The epitopes of the cell-, fibrin-, collagen-binding FN domains and the extra domain A (EDA) FN segment retained the ability to bind their specific monoclonal antibodies, whereas the fibrin-heparin domain (N-terminal end) and the area around the disulfide bridges (C-terminal end) of the FN polypeptide did not show any reactivities with their respective specific antibodies. The mean values of cell- (338.4±138.4 and 398.3±310mgL(-1)), fibrin- (79.1±38.5 and 145.2±188.8mgL(-1)) and collagen-binding (19±19.8 and 50.9±73.4mgL(-1)) FN domain immunoreactivities and the relative amount of (EDA)FN did not show any significant differences between the normal and leucocytospermic groups. The high values of standard deviations for the FN domain immunoreactivities in the leucocytospermic group probably results from different aetiology of leucocytospermia. The profile of FN fragmentation and alterations of FN domain immunoreactivities in seminal plasma may influence their engagement in the fertilisation process. The analysis of seminal FN molecular status would be helpful for selecting the highest quality spermatozoa for use in assisted reproduction techniques.

Leukocytes and oxidative stress: dilemma for sperm function and male fertility

Spermatozoa are constantly exposed to the interphase between oxidation through high amounts of reactive oxygen species (ROS) and leukocytes, and reduction by means of scavengers and antioxidants. Considering the very special functions as being the only cells with such high polarization and exerting their functions outside the body, even in a different individual, the female genital tract, the membranes of these cells are chemically composed of an extraordinary high amount of polyunsaturated fatty acids. This in turn, renders them very susceptible to oxidative stress, which is defined as an imbalance between oxidation and reduction towards the oxidative status. As a result, ROS deriving from both leukocytes and the male germ cells themselves cause a process called 'lipid peroxidation' and other damages to the sperm cell. On the other hand, a certain limited amount of ROS is essential in order to trigger vital physiological reactions in cells, including capacitation or the acrosome reaction in sperm. The treatment of patients with antioxidants to compensate the oxidative status caused by oxidative stress is highly debated as uncontrolled antioxidative treatment might derail the system towards the reduced status, which is also unphysiological and can even induce cancer. This paradox is called the 'antioxidant paradox'. Therefore, a proper andrological diagnostic work-up, including the evaluation of ROS levels and the antioxidant capacity of the semen, has to be carried out beforehand, aimed at keeping the fine balance between oxidation and scavenging of vital amounts of ROS.

Immunology of the Testis and Male Reproductive Tract

A large body of evidence points to the existence of a close, dynamic relationship between the immune system and the male reproductive tract, which has important implications for our understanding of both systems. The testis and the male reproductive tract provide an environment that protects the otherwise highly immunogenic spermatogenic cells and sperm from immunological attack. At the same time, secretions of the testis, including androgens, influence the development and mature functions of the immune system. Activation of the immune system has negative effects on both androgen and sperm production, so that systemic or local infection and inflammation compromise male fertility. The mechanisms underlying these interactions have begun to receive the attention from reproductive biologists and immunologists that they deserve, but many crucial details remain to be uncovered. A complete picture of male reproductive tract function and its response to toxic agents is contingent upon continued exploration of these interactions and the mechanisms involved.

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.

Effect of leukocytospermia and processing by discontinuous density gradient on sperm nuclear DNA fragmentation and mitochondrial activity

PURPOSE

To assess the effect of leukocytospermia and semen processing on sperm DNA and mitochondria.

METHODS

Twenty-two patients with and 41 without leukocytospermia were included. Sperm DNA fragmentation was assessed by the Comet assay, and mitochondrial activity by a colorimetric method for active mitochondria. Semen was processed using Percoll, and motility, DNA fragmentation, and mitochondrial activity were analyzed pre- and post-processing.

RESULTS

No differences were observed in age, abstinence, volume, sperm morphology, progressive motility, concentration, and vitality (p>0.10). Variables were grouped according to time (pre- vs post-processing) and group (leukocytospermia vs non-leukocytospermia) because no interactions could be observed. Leukocytospermia was associated to increased DNA fragmentation, while semen processing led to a decrease in DNA fragmentation and to increased mitochondrial activity.

CONCLUSION

While semen processing selects sperm with higher rates of DNA integrity independent of the presence or absence of leukocytes in semen, samples without leukocytospermia present more sperm without DNA fragmentation. Semen processing also selects sperm with higher mitochondrial activity.

Prevalence of asymptomatic inflammatory (National Institutes of Health Category IV) prostatitis in young men according to semen analysis

OBJECTIVES

To determine the prevalence of asymptomatic inflammatory (National Institutes of Health category IV) prostatitis in a cross-sectional community sample of young men.

METHODS

The study group consisted of 565 men aged 18.9 +/- 1.8 years (mean +/- standard deviation). Cytologic examination of all ejaculates (using Bryan-Leishman stained slides), as well as analysis for basic semen parameters (volume, concentration, and motility) and clinical examination for possible pathologies in the genital region, were performed. Subjects with any clinical symptoms of inflammation were excluded. Levels of prostate-specific antigen in blood serum and interleukin-6 in seminal plasma were determined as well.

RESULTS

The prevalence of asymptomatic inflammatory prostatitis (greater than 1 x 10(6) white blood cells [WBC]/mL in semen, according to World Health Organization guidelines) was 6.0%, but when we used a lower threshold suggested by our previous studies (greater than 0.2 x 10(6) WBC/mL), the prevalence was 19.0%. In this study the analysis did not show any significant effect of leukocytospermia on sperm quality, except higher sperm concentration in subjects with moderate leukocytospermia (0.2-1 x 10(6) WBC/mL). We did not detect any seasonal differences in the prevalence of asymptomatic inflammatory prostatitis. Interleukin-6 and prostate-specific antigen levels were significantly higher in leukocytospermic subjects than in those without leukocytospermia.

CONCLUSIONS

Asymptomatic inflammatory prostatitis has a notable prevalence among healthy young men, suggesting the need for further studies to investigate pathogenetic mechanisms of the disease. Lack of negative effect of leukocytospermia on basic semen parameters may indicate higher functional reserve of accessory sex glands in this age group.

Clinical relevance of oxidative stress in male factor infertility: an update

Male factor has been considered a major contributory factor to infertility. Along with the conventional causes for male infertility such as varicocele, cryptorchidism, infections, obstructive lesions, cystic fibrosis, trauma, and tumors, a new, yet important cause has been identified: oxidative stress. Oxidative stress (OS) is a result of the imbalance between reactive oxygen species (ROS) and antioxidants in the body, which can lead to sperm damage, deformity and eventually male infertility. This involves peroxidative damage to sperm membrane and DNA fragmentation at both nuclear and mitochondrial levels. OS has been implicated as the major etiological factor leading to sperm DNA damage. OS-induced DNA damage can lead to abnormalities in the offspring including childhood cancer and achondroplasia. In this article, we discuss the need of ROS in normal sperm physiology, the mechanism of production of ROS and its pathophysiology in relation to male reproductive system. The benefits of incorporating antioxidants in clinical and experimental settings have been enumerated. We also highlight the emerging concept of utilizing OS as a method of contraception and the potential problems associated with it.

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.

Diagnostic approach to the infertile male patient

There are several objectives to be achieved during the diagnostic evaluation of a male partner of an infertile partnership. The first is to identify whether or not there is a male factor present and, if so, whether this is attributable to an underlying medical illness. The second is to identify the cause of reduced male fertility and whether or not it is amenable to therapeutic intervention.

Comparison of reactive oxygen species concentration in seminal plasma and semen parameters in partners of pregnant and non-pregnant patients after IVF/ICSI

The aims of this study were (i) to determine and compare the concentration of reactive oxygen species (ROS) and total antioxidant status (TAS) in seminal plasma and sperm parameters of the male partners of patients undergoing IVF or intracytoplasmic sperm injection (ICSI) treatment and (ii) to establish the relationship between ROS and TAS concentrations and sperm quality and their effect on fertilization and pregnancy rate of patients who achieved a pregnancy and those who were unsuccessful. Twenty-six IVF and 22 ICSI patients were included in this study. The ROS concentration in seminal plasma and sperm concentration, vitality (eosin test), motility, morphology, membrane integrity (HOS test), maturity (chromomycin, CMA3) and DNA fragmentation (TUNEL) results and their relationship to fertilization and pregnancy were analysed. ROS concentrations were similar regarding the seminal plasma of male partners of patients who achieved a pregnancy and those who were unsuccessful. The other semen parameters, concentration, motility, vitality, membrane and DNA integrity, were comparable in both groups. However, both groups demonstrated a negative correlation between ROS concentration and sperm vitality, membrane integrity and morphology. Moreover, an inverse correlation was found between TUNEL, vitality, and membrane integrity. In conclusion, ROS concentration in seminal plasma affects the quality of spermatozoa. A negative correlation between the ROS concentration in seminal plasma and fertilization rate in both IVF/ICSI programmes was shown.

Role of reactive oxygen species and antioxidants on pathophysiology of male reproduction

The excessive generation of reactive oxygen species (ROS) by abnormal spermatozoa and contaminating leukocytes has been defined as one of the few etiologies for male infertility. Administration of antioxidants in patients with 'male factor' infertility has begun to attract considerable interest. The main difficulty of such an approach is our incomplete understanding of the role of free radicals in normal and abnormal sperm function leading to male infertility. Mammalian spermatozoa membranes are very sensitive to free radical induced damage mediated by lipid peroxidation, as they are rich in polyunsaturated fatty acids. Limited endogenous mechanisms exist to reverse these damages. ROS attacks the fluidity of the sperm plasma membrane and the integrity of DNA in the sperm nucleus. ROS induced DNA damage accelerate the germ cell apoptosis. Unfortunately spermatozoa are unable to repair the damage induced by excessive ROS as they lack the cytoplasmic enzymes required to accomplish the repair. Assessment of such oxidative stress status (OSS) may help in the medical treatment. Treatment strategies must be directed toward lowering of ROS levels to keep only a small amount necessary to maintain normal cell function.

Value of Counting White Blood Cells (WBC) in Semen Samples to Predict the Presence of Bacteria

OBJECTIVES

To investigate the correlation between the presence of white blood cells (WBC) without the use of specific stain to differentiate leukocytes and the presence of bacteria in semen samples of infertile men.

METHODS

A total of 143 semen samples of men who attended an andrologic clinic for the evaluation of fertility were investigated using routine semen analysis (according to WHO laboratory guidelines) and bacterial culture.

RESULTS

WBC were found in 43.4% (62/143). There were no WBC in 56.6% (81/143) of the samples (group I) while WBC were found in 43.4% (62/143) of the samples (group II). Pathogenic bacteria were detected in 48.2% (39/81) in group I and in 54.9% (34/62) in group II, all in all Bacteriospermia was present in 51.1% (73/143). The most common bacteria were Ureaplasma urealyticum, Enterococcus faecalis and Escherichia coli (23.8%, 16.8%, and 7.0% of samples, respectively). The sensitivity/specificity for detecting bacteria was 0.47/0.60 at a cut-off level of 0.25 Mio/mL WBC and 0.16/0.84 at a cut-off level of WBC 1 Mio/mL, representing likelihood ratios of 1.16 and 1.04, respectively. The greatest ratio between sensitivity and specificity (0.37/0.72) was found at a cut-off level of 0.5 Mio/mL WBC, with a likelihood ratio of 1.29.

CONCLUSIONS

Counting WBC instead of a specific stain for the detection of leukocytes has only a poor sensitivity/specificity for the detection of bacteria.

Ketotifen improves sperm motility and sperm morphology in male patients with leukocytospermia and unexplained infertility

In an open, uncontrolled study, the effect of 12 weeks of daily administration of ketotifen, an antihistamine-like drug with a mast cell stabilizing effect, on the semen quality of 55 men with leukocytospermia and unexplained infertility was examined. After 4 weeks of treatment, white blood cell count dramatically diminished and was accompanied by a significant improvement in sperm motility. A significant increase of morphologically normal sperm cells was observed at 8 weeks of treatment, and these changes remained until at least 4 weeks after the end of treatment.