The effect of human papillomavirus infection on sperm cell motility

HPV infection and its correlation with p53 and Bcl-2 among pregnant mothers and their infants

The investigation of perinatal transmission of HPV is vital for early screening of cervical/oral cancers. Here, transmission of HPV from the pregnant women to their infants was studied. p53 and Bcl-2 expressions and their correlations with HPV infection were examined. HPV infection was detected in the cervical and oral swabs of 135 mother-baby pairs employing both PCR and HC-II methods. 1 year follow-up with an interim visit at 3 months for mothers and 6 months for babies was performed. Immunocytochemistry of p53 and Bcl-2 using the streptavidin-biotin peroxidase method was performed. Prevalence of HPV infection in the mothers was 28.14%, (38/135) and 30.37% (41/135) determined by the PCR and HC-II methods respectively. HPV 16 and/or 18 was identified in 81.57% (31/38) and 82.92% (34/41) of the HPV + women estimated by PCR and HC-II methods respectively. Prevalence rate of HPV 16 among the HPV + pregnant women was 63.15% (24/38) and 65.85% (27/41) determined by PCR and HC-II methods respectively. The frequency of perinatal transmission was 21.05% (8/38) and 21.95% (9/41) determined by PCR and HC-II methods respectively at birth. The HPV + infants in the follow up study cleared the infection within 6 weeks. An abnormal nuclear expression of p53 and cytoplasmic expression of Bcl-2 were observed in the HPV + mother-baby pairs. Cesarean section did not protect the infants against perinatal HPV transmission. The detection of p53 and Bcl-2 proteins in the HPV + mother-baby pairs suggests that these biomarkers may be important in the early screening of oral/cervix cancers in positive cases.

Molecular study of the presence and transcriptional activity of HPV in semen

PURPOSE

Human Papillomavirus (HPV) in semen represents a controversial topic. Recent evidence suggests a correlation with poor semen quality, but its detection is still unstandardized in this biological fluid. Thus, the aims of this study were to verify the ability of nested PCR to reveal HPV-DNA in semen; to evaluate association of seminal HPV with sperm parameters and risk factors for infection; to investigate the rate of HPV-DNA positivity in patients with and without risk factors; to assess HPV transcriptional activity.

METHODS

We enrolled sexually active men and collected clinical and anamnestic data during andrological and sexually transmitted infections (STIs) evaluation. For each patient, we performed semen analysis and nested PCR to detect HPV-DNA in semen. In positive semen samples, we proceeded with genotyping and RNA quantification to detect HPV transcriptional activity.

RESULTS

We enrolled 185 men (36.0 ± 8.3 years), of which 85 with (Group A) and 100 without HPV risk factors (Group B). Nested PCR was able to reveal HPV-DNA in semen, discovering a prevalence of 8.6% (11.8% in Group A and 6% in Group B, respectively). We observed no correlation between sperm quality and seminal HPV. Genital warts and previous anogenital infection were significantly associated with the risk of HPV positivity in semen. Moreover, no viral transcriptional activity was detected in positive semen samples.

CONCLUSIONS

Our study suggests that searching for seminal HPV could be important in patients both with and without risk factors, especially in assisted reproduction where the risk of injecting sperm carrying HPV-DNA is possible.

HPV-related diseases in male patients: an underestimated conundrum

PURPOSE

Human papillomavirus (HPV) infection is the most common sexually transmitted disease, in males and females worldwide. While the role of HPV in female diseases is well known and largely studied, males have negligibly been included in these programs, also because the proportion of women suffering and dying from HPV-related diseases is much larger than men. The aim of this review is to focus on HPV-related diseases in male patients.

METHODS

We performed a literature analysis on the electronic database PubMed. We considered randomized trials, observational and retrospective studies, original articles having as topic the relationship between HPV male infection and the following items: oral, anal penile cancers, warts, condylomas, male infertility, altered sperm parameters, anti-sperm antibodies (ASA). We also included experimental in vitro studies focused on the effects of HPV infection on oocyte fertilization, blastocyst development, and trophoblastic cell invasiveness. In addition, studies describing the adjuvant administration of the HPV vaccination as a possible strategy to promote HPV clearance from semen in infected males were included.

RESULTS

Regarding head and neck HPV-related diseases, the most important non-neoplastic disease is recurrent respiratory papillomatosis (RRP). Regarding neoplastic diseases, the proportion of head and neck cancers attributable to HPV has increased dramatically worldwide. In addition, nowadays, it is thought that half of head and neck squamous cell carcinomas (HNSCCs) cases in the United States are caused by infection with high-risk HPV. HPV is noteworthy in andrological practice too. It was described as having a high HPV prevalence, ranging between 50 and 70%, in male penile shaft, glans penis/coronal sulcus, semen as well as in scrotal, perianal, and anal regions. Moreover, in male patients, HPV infection has been associated, among other diseases, with penile cancers. HPV semen infection has been reported in about 10% in men from the general population and about 16% in men with unexplained infertility, although these data seem widely underestimated according to clinical experience. In particular, HPV semen infection seems to be most related to asthenozoospermia and to anti-sperm antibodies (ASAs).

CONCLUSIONS

HPV infection represents a health problem with a detrimental social and public impact. Despite this evidence, little has been done to date to widely promote vaccination among young males.

Human Papillomavirus and Male Infertility: What Do We Know?

In recent years, increasing attention has been paid to understanding the causes of infertility, which is being recognized as a growing health problem affecting large numbers of couples worldwide. Male infertility is a contributing factor in approximately 30-40% of cases, and one of its etiological causes is sexually transmitted infections (STIs). Among sexually transmitted pathogens, human papillomavirus (HPV) can contribute in various ways to the failure of spontaneous and assisted reproduction, acting in the different phases of conception, especially in the early ones. In particular, HPV infection can affect sperm DNA integrity, sperm motility, count, viability, and morphology and can induce the production of anti-sperm antibodies (ASAs). In this narrative review, we aimed to provide an overview of existing research on the potential adverse effects of HPV infection on male reproductive health. Furthermore, we analyzed how limiting the spread of the infection, particularly with gender-neutral vaccination, could be a possible therapeutic tool to counteract male and female fertility problems.

[Infections and male infertility]

BACKGROUND

The role of urogenital infections in male infertility has long been the subject of debate.

METHODS

A bibliographic search limited to English-language literature on human subjects published before 5/2023 resulted in the selection of 189 articles.

RESULTS

Male infertility is often of multifactorial aetiology, and to optimise the prognosis it is important to manage all the factors that can be corrected, including infectious causes, which represent one of the most frequent aetiologies. The infectious agents involved in urogenital infections are most often bacterial or viral, and more rarely parasitic. They can infect the seminal tract, male accessory glands and/or testicles, and usually result in inflammation and increased oxidative stress. These infections reduce male fertility, in particular by altering spermogram parameters and increasing sperm DNA fragmentation. For these reasons, the search for a urogenital infection should be systematic, involving a careful history and clinical examination, ultrasound and systematic bacteriological tests guided by clinical findings. Aetiological treatment may be proposed depending on the picture and the germ involved.

CONCLUSION

This review should help the urologist to establish an accurate diagnosis of the form and extent of the infection, and enable him to define an appropriate therapeutic strategy, tailored to the patient, in order to obtain the best chances of improving male fertility.

Semen human papillomavirus (HPV) shedding in males: frequency, clinical significance, and reproductive outcomes—literature review

Background

The interest in the HPV status of the male has risen after the discovery of HPV shedding in the semen. To date, there is no consensus on the true prevalence of male HPV infection, yet there is a rising body of evidence suggesting that male HPV infection might negatively affect the sperm parameters.

Main body

The concern that HPV can lead to a couple’s infertility and affect reproductive outcomes had increased after the multiple publications of semen criteria perturbations specifically the asthenospermia associated with HPV infection. An extensive literature review was performed to define the actual frequency of male HPV infection as well as the true extent of sperm analysis perturbations related to the HPV illness. We also intended to define the impact of these infections on reproductive outcomes and to highlight any treatment plans for affected couples.

Conclusion

HPV is a prevalent disease with a rising concern among the male populations given the suggested impact on sperm motility as well as the pregnancy and miscarriage rates post-ART treatment. Vaccines are being studied now as a possible infertility adjunct treatment for males who are already infected.

Exploring the potential impact of human papillomavirus on infertility and assisted reproductive technology outcomes

Human papillomavirus (HPV) is a common sexually transmitted disease that has been linked to both cancer and reproductive health issues. While its impact on fertility and pregnancy success has been studied, there is still too little evidence about the influence of HPV on assisted reproductive technology (ART). Therefore, there exists a need for HPV testing in couples undergoing infertility treatments. Infertile men have been found to have a higher prevalence of seminal HPV infection, which can compromise sperm quality and reproductive function. As such, it could be important to investigate the correlation between HPV and ART outcomes in order to improve the quality of evidence. Understanding the potentially detrimental effects of HPV on ART outcomes may have promising important implications for the management of infertility. This minireview summarizes the so far limited developments in this area and highlights the major need for further well-designed studies to address this issue.

Vertical transmission of Human papillomavirus: experience from a center of southern Italy

BACKGROUND

Human papillomavirus (HPV) represents a group of DNA viruses, sexually transmitted, and widely accepted as a cause of invasive squamous cell carcinomas. The virus prevalence is critical worldwide. However, the possibility of perinatal transmission during pregnancy is not well understood as well as the risks for the newborn.

METHODS

Our study analyzed pregnant women referred to the obstetric outpatient room of the Department of Gynecology and Obstetrics of Sant'Anna and San Sebastiano University Hospital in Caserta, Italy. Cervicovaginal samples were achieved from patients during the first trimester and tested for HPV. The specimen was repeated during the third trimester for HPV-positive patients. After the birth, we took a placenta sample and an eye, pharyngeal, mouth, and genital samples in children from HPV positive mothers, at 36-48 hours after birth and three and six months.

RESULTS

We found out a high prevalence of HPV infections in the recruited patients: 71 participants were positive at the HPV test in the first trimester (45%), and 17 (14%) showed a positivity in the placental samples. However, there was a low prevalence of viral infection in newborns, and six newborns were positive for HPV at birth (9%).

CONCLUSIONS

HPV vertical transmission represents a critical obstetric topic, and the transplacental passage of the virus represents a possible cause. However, further studies are necessary to deepen the pathological mechanism and assess the risks for the newborn.

Microbiology and immune mechanisms associated with male infertility

Up to 50% of infertility is caused by the male side. Varicocele, orchitis, prostatitis, oligospermia, asthenospermia, and azoospermia are common causes of impaired male reproductive function and male infertility. In recent years, more and more studies have shown that microorganisms play an increasingly important role in the occurrence of these diseases. This review will discuss the microbiological changes associated with male infertility from the perspective of etiology, and how microorganisms affect the normal function of the male reproductive system through immune mechanisms. Linking male infertility with microbiome and immunomics can help us recognize the immune response under different disease states, providing more targeted immune target therapy for these diseases, and even the possibility of combined immunotherapy and microbial therapy for male infertility.

Viral tropism for the testis and sexual transmission

The mammalian testis adopts an immune privileged environment to protect male germ cells from adverse autoimmune reaction. The testicular immune privileged status can be also hijacked by various microbial pathogens as a sanctuary to escape systemic immune surveillance. In particular, several viruses have a tropism for the testis. To overcome the immune privileged status and mount an effective local defense against invading viruses, testicular cells are well equipped with innate antiviral machinery. However, several viruses may persist an elongated duration in the testis and disrupt the local immune homeostasis, thereby impairing testicular functions and male fertility. Moreover, the viruses in the testis, as well as other organs of the male reproductive system, can shed to the semen, thus allowing sexual transmission to partners. Viral infection in the testis, which can impair male fertility and lead to sexual transmission, is a serious concern in research on known and on new emerging viruses. To provide references for our scientific peers, this article reviews research achievements and suggests future research focuses in the field.

Tale of Viruses in Male Infertility

Male infertility is a condition where the males either become sterile or critically infertile. The World Health Organisation assessed that approximately 9% of the couple have fertility issues where the contribution of the male partner was estimated to be 50%. There are several factors that can amalgamate to give rise to male infertility. Among them are lifestyle factors, genetic factors and as well as several environmental factors. The causes of male infertility may be acquired, congenital or sometimes idiopathic. All these factors adversely affect the spermatogenesis process as well as they impart serious threats to male genital organs thus resulting in infertility. Viruses are submicroscopic pathogenic agents that rely on host for their replication and survival. They enter the host cell, hijack the host cell machinery to aid their own replication and exit the cell for a new round of infection. With the growing abundance of different types of viruses and the havoc they have stirred in the form of pandemics, it is very essential to decipher their route of entry inside the human body and understand their diverse functional roles in order to combat them. In this chapter, we will review how viruses invade the male genital system thus in turn leading to detrimental consequence on male fertility. We will discuss the tropism of various viruses in the male genital organs and explore their sexual transmissibility. This chapter will summarise the functional and mechanistic approaches employed by the viruses in inducing oxidative stress inside spermatozoa thus leading to male infertility. Moreover, we will also highlight the various antiviral therapies that have been studied so far in order to ameliorate viral infection in order to combat the harmful consequences leading to male infertility.

Evaluation of the Presence of Bacterial and Viral Agents in the Semen of Infertile Men: A Systematic and Meta-Analysis Review Study

Objectives

Infections in the male genitourinary system with bacterial and viral agents may play a significant role in male infertility. These agents usually infect the urethra, seminal vesicles, prostate, epididymis, vas deferens, and testes retrograde through the reproductive system. A meta-analysis review study was performed to evaluate the presence of bacterial and viral agents in the semen of infertile men and its correlation with infertility.

Methods

Relevant cross-sectional and/or case-control studies were found by an online review of national and international databases (Web of Science, PubMed, Scopus, Science Direct, and Google scholar), and suitable studies were selected. A checklist determined the qualities of all studies. Heterogeneity assay among the primary studies was evaluated by Cochran’s Q test and I² index (significance level 50%). A statistical analysis was conducted using the Comprehensive Stata ver. 14 package (StataCorp, College Station, TX, United States).

Results

Seventy-two studies were included in this meta-analysis. Publication bias was compared with Egger’s test, and the impact of each research on overall estimate was evaluated by sensitivity analysis. In 56 studies, the rate of bacterial infections in the semen of infertile men was 12% [95% confidence interval (CI): 10–13]. Also, in 26 case-control studies, the association of infertility in men with bacterial infections was evaluated. The results show that the odds ratio of infertility in men exposed to bacterial infections is 3.31 times higher than that in non-infected men (95% CI: 2.60–4.23). Besides, in 9 studies that examined the prevalence of human papillomavirus (HPV), herpes simplex virus 1 (HSV1), herpes simplex virus 2 (HSV2), and herpes simplex virus 1-2 (HSV1-2) in infertile men, the frequency of these viruses was 15% (95% CI: 9–21). In 6 case-control studies, the association between human cytomegalovirus (HCMV), Cytomegalovirus (CMV), and HPV and male infertility was evaluated. The chance of male infertility due to exposure to these viruses was 2.24 times higher than those without exposure to these viruses (CI 95%: 1.9–4.52). The results show that the chance of infertility in men exposed to bacteria was significantly higher than that in the uninfected population.

Conclusion

This meta-analysis showed that viral and bacterial infections are a risk factor and could impair male fertility potential. Moreover, our study supports the hypothesis that bacterial and viral infections of the genital tract correlate positively with impairment of sperm quality in the male population.

The Impact of 9-Valent HPV Vaccination on Couple Infertility Prevention: A Comprehensive Review

A comprehensive literature review was performed to determine the relationship between HPV infection and infertility and the eventual role of the 9-valent vaccine for infertility prevention. The search was extended from January 1997 through July 2021. Data collected from selected articles focused on three main topics: statistical associations between HPV prevalence and assisted reproductive technology (ART) outcome, association between HPV and characteristics of semen, and associations between HPV and miscarriage. Articles that identified HPV genotypes were selected for this review to study the possible role of the 9-valent vaccine in infertility prevention. To date, there is no agreement on the implication HPV female infection has on the fertility and miscarriage rate. Although it can be stated that HPV prevalence among couples with infertility undergoing ART treatment is consistent, it does not seem to affect the performance of oocytes. Otherwise, HPV infection affects sperm parameters, in particular spermatozoa motility. When an association can be found, most cases of HR-HPV involved are those included in the 9-valent vaccine. The correlation between HPV male infection both with asthenozoospermia and increased risk of pregnancy loss could recommend the extension of anti-HPV vaccination to adolescent males along with cancer prevention. Despite the fact that the relation between 9-valent HPV genotypes involved in female infection and miscarriage/infertility is not clear, the impact of this virus on health reproduction is evident. Considering this, the importance of HPV vaccination in adolescent females is confirmed. A vaccine efficacy study could be useful to confirm the importance of primary prevention for couple reproductive health.

Genitourinary Infections Related to Circumcision and the Potential Impact on Male Infertility

Male circumcision (MC) is one of the oldest surgical procedures still completed today. Medical indications for MC include phimosis, recurrent balanitis, cosmesis, and infection prevention. In this review, we mainly focus on the role of MC in the prevention of human immunodeficiency virus, human papillomavirus, herpes simplex virus, gonorrhea, chlamydia, chancroid, and syphilis, and the subsequent impact of these genitourinary infections on male fertility. Overall, many compelling data support that MC may play an essential role in both genitourinary infection prevention and male fertility.

Genetic instability and anti-HPV immune response as drivers of infertility associated with HPV infection

Human papillomavirus (HPV) is a sexually transmitted infection common among men and women of reproductive age worldwide. HPV viruses are associated with epithelial lesions and cancers. HPV infections have been shown to be significantly associated with many adverse effects in reproductive function. Infection with HPVs, specifically of high-oncogenic risk types (HR HPVs), affects different stages of human reproduction, resulting in a series of adverse outcomes: 1) reduction of male fertility (male infertility), characterized by qualitative and quantitative semen alterations; 2) impairment of couple fertility with increase of blastocyst apoptosis and reduction of endometrial implantation of trophoblastic cells; 3) defects of embryos and fetal development, with increase of spontaneous abortion and spontaneous preterm birth. The actual molecular mechanism(s) by which HPV infection is involved remain unclear. HPV-associated infertility as Janus, has two faces: one reflecting anti-HPV immunity, and the other, direct pathogenic effects of HPVs, specifically, of HR HPVs on the infected/HPV-replicating cells. Adverse effects observed for HR HPVs differ depending on the genotype of infecting virus, reflecting differential response of the host immune system as well as functional differences between HPVs and their individual proteins/antigens, including their ability to induce genetic instability/DNA damage. Review summarizes HPV involvement in all reproductive stages, evaluate the adverse role(s) played by HPVs, and identifies mechanisms of viral pathogenicity, common as well as specific for each stage of the reproduction process.

Is HPV the Novel Target in Male Idiopathic Infertility? A Systematic Review of the Literature

Infertility is an important health problem that affects up to 16% of couples worldwide. Male infertility is responsible for about 50% of the cases, and the various causes of male infertility may be classified in pre-testicular (for example hypothalamic diseases), testicular, and post-testicular (for example obstructive pathologies of seminal ducts) causes. Sexually transmitted infections (STI) are increasingly widely accepted by researchers and clinicians as etiological factors of male infertility. In particular, several recent reports have documented the presence of HPV in seminal fluid and observed that sperm infection can also be present in sexually active asymptomatic male and infertile patients. In this review, we aimed to perform a systematic review of the whole body of literature exploring the impact of HPV infection in natural and assisted fertility outcomes, from both an experimental and a clinical point of view. Starting from in-vitro studies in animals up to in-vivo studies in humans, we aimed to study and evaluate the weight of this infection as a possible cause of idiopathic infertility in males with any known cause of conception failure.

Evaluation of human papilloma virus in semen as a risk factor for low sperm quality and poor in vitro fertilization outcomes: a systematic review and meta-analysis

OBJECTIVE

To analyze the effect of human papilloma virus (HPV) sperm infection on sperm parameters and in vitro fertilization (IVF) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Men with HPV sperm infection and couples undergoing IVF.

INTERVENTIONS

Searches were conducted in the following databases: Medline(R), PubMed, Embase, Web of Science, Scopos, and the Cochrane Library. We included studies examining sperm parameters and IVF results in patients with and without HPV sperm infection.

MAIN OUTCOME MEASURES

Sperm analysis (concertation, count, volume, motility, morphology), according to the World Health Organization manual, pregnancy rate (PR), and miscarriage rate (MR).

RESULTS

Sixteen studies were included in this meta-analysis. The presence of HPV had a significant association with impaired sperm parameters in terms of concentration (mean difference [MD] -4.48, 95% confidence interval [CI] - 6.12 to -2.83), motility (MD -11.71, 95% CI - 16.15 to -7.26), and morphology (MD -2.44, 95% CI - 4.08 to -0.79. A review of the literature regarding ART outcomes showed an association between HPV infection and decreased PR, and an even stronger association between HPV infection and increased MR.

CONCLUSION

Our meta-analysis shows a negative effect of HPV on sperm concentration, motility, and morphology. Further subgroup and categorical analysis confirmed the clinical significance of impaired sperm motility in HPV-infected sperm, although the sperm count and morphology must be carefully analyzed. The studies reviewed reported lower PR and increased MR in couples with HPV-infected sperm. As most studies had a moderate risk of bias, these observations warrant further large, well-designed studies before introducing clinical management recommendations.

PROSPERO REGISTRATION NUMBER

CRD42019127419.

Negative Impact of Elevated DNA Fragmentation and Human Papillomavirus (HPV) Presence in Sperm on the Outcome of Intra-Uterine Insemination (IUI)

We wanted to determine the sperm DNA fragmentation index (DFI) cutoff for clinical pregnancies in women receiving intra-uterine insemination (IUI) with this sperm and to assess the contribution of Human Papillomavirus (HPV) infection on sperm DNA damage and its impact on clinical pregnancies. Prospective non-interventional multi-center study with 161 infertile couples going through 209 cycles of IUI in hospital fertility centers in Flanders, Belgium. Measurement of DFI and HPV DNA with type specific quantitative PCRs (HPV 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68) in sperm before its use in IUI. Clinical pregnancy (CP) rate was used as the outcome to analyze the impact on fertility outcome and to calculated the clinical cutoff value for DFI. A DFI criterion value of 26% was obtained by receiver operating characteristic (ROC) curve analysis. Couples with a male DFI > 26% had significantly less CPs than couples with DFI below 26% (OR 0.0326; 95% CI 0.0019 to 0.5400; p = 0.017). In sperm, HPV prevalence was 14.8%/IUI cycle. Sperm samples containing HPV had a significantly higher DFI compared to HPV negative sperm samples (29.8% vs. 20.9%; p = 0.011). When HPV-virions were present in sperm, no clinical pregnancies were observed. More than 1 in 5 of samples with normal semen parameters (17/78; 21.8%) had an elevated DFI or was HPV positive. Sperm DFI is a robust predictor of clinical pregnancies in women receiving IUI with this sperm. When DFI exceeds 26%, clinical pregnancies are less likely and in vitro fertilization techniques should be considered.

Lactobacillus iners and gasseri, Prevotella bivia and HPV Belong to the Microbiological Signature Negatively Affecting Human Reproduction

Infertile couples undergoing the use of assisted reproductive technology are a good study model to evaluate the microbiological signatures affecting reproductive health. We tested vaginal lavages, follicular fluids, embryo culture mediums, and seminal fluids from 47 couples for their microbiome composition and HPV infection. Twenty-five infertile couples were diagnosed with unexplained infertility, whereas 22 were diagnosed with explained infertility. Lactobacilli were dominant in the vaginal lavages of both patient groups, and the most abundant species was L. iners (CST III), which is linked to a decreased fertility rate. Besides this, L. gasseri—which is known to be associated with oocyte DNA fragmentation and decreased sperm mobility—was identified in the seminal fluids, follicular fluids, and embryo culture media of the unexplained infertility group. Prevotella was increased in the seminal fluids of the explained infertility group, along with HPV-positive seminal fluids: an infection commonly associated with infertility, especially male infertility. Prevotella has been described to negatively affect sperm motility. Taken together, these results suggest that the profiling of the reproductive tract microbiome can add new perspectives to human reproduction.

Seminal human papillomavirus infection and reproduction: a systematic review and meta-analysis

BACKGROUND

The impact of human papillomavirus (HPV) on male fertility and associated reproductive outcomes has not been clarified.

OBJECTIVES

To elucidate the prevalence of seminal HPV infection and assess the associated effects on seminal parameters, male infertility, and reproductive outcomes.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed in accordance with PRISMA guidelines. A search was performed using PubMed, MEDLINE, SCOPUS, and Cochrane databases. Studies published until November 2019 were included. HPV prevalence, risk of infertility, seminal parameters, and reproductive outcomes were evaluated among the general population and infertile men.

RESULTS

Fifty studies met the inclusion criteria. The prevalence of seminal HPV infection is significantly higher in infertile compared to the general population (20.9% versus 8.2%). A significant association between seminal HPV infection and male infertility (OR 3.30, 95% CI 1.87-5.84), even when adjusting for female infertility (OR 3.02, 95% CI = 2.11-4.33) was founded. In addition, HPV infection is related to a significant decrease in progressive motility (DM -10.35, IC -13.75, -6.96), a low sperm morphology score (DM -2.46, 95% CI -3.83, -1.08), and a significant increase in the sperm DNA fragmentation index (7.24, 95% CI 4.44.10.03) compared with HPV-negative patients. It was also observed an increased risk of miscarriage (OR 5.13, 95% CI 2.40,10.94), and a reduced chance of ongoing pregnancy (OR 0.33, IC 95% 0.13,0,82) in patients undergoing ART with seminal HPV infection.

DISCUSSION

Infertile men have a higher prevalence of seminal HPV infection compared to the general population, regardless of the HPV genotype detected.

CONCLUSIONS

HPV in semen may have an impact in sperm quality and reproductive outcomes. Additional well-designed studies are warranted to improve the quality of evidence.

Hyaluronidase-based swim-up for semen selection in patients with human papillomavirus semen infection

Infection by human papillomavirus (HPV) represents one of the most common sexually transmitted diseases in both men and women worldwide. Recently, the detection of HPV virions in the semen of a large percentage of sexually active men has been associated with detrimental effects on both sperm parameters and on assisted reproductive technologies (ART) treatment outcomes. Conventional semen washing procedure used in ART have proved to be ineffective in removing HPV bound to sperm, requiring the identification of more effective and specific methods. In the present study, we assessed the possible use of hyaluronidase for the detachment of HPV from sperm cell surface. Semen samples from five normozoospermic control subjects (CTRL) were incubated with HPV virus-like particles (HPV-VLP) and treated with hyaluronidase by both a modified swim-up procedure (M-SU) and single-cell approach (SCA). The treatment with hyaluronidase was associated with the complete loss of HPV-VLP signal on sperms by both M-SU and SCA. In addition, semen samples from 12 HPV-positive infertile patients were treated with hyaluronidase 80 IU/mL by M-SU, resulting in the complete loss of HPV-DNA signal from sperm surface. Finally, the possible impact of hyaluronidase treatment on sperm parameters was assessed on both sperms from the five CTRL subjects and on further five oligo-astheno-terato-zoospermic (OAT) patients, both HPV negative. The treatment with hyaluronidase was equally associated with a slight reduction of sperm viability and progressive motility in both CTRL and OAT. In conclusion, the treatment with hyaluronidase removed efficiently and safely HPV virions bound to spermatozoa.

Female Human Papillomavirus Infection Associated with Increased Risk of Infertility: A Nationwide Population-Based Cohort Study

Objective. This study investigated whether women with a history of human papillomavirus (HPV) infection have an increased risk of infertility. Material and Methods. All patients with an HPV infection (n = 11,198) in Taiwan’s National Health Insurance Research Database (2000–2012) were propensity score matched with control subjects (n = 11,198) without an HPV infection by age, sex, index year, and relevant co-morbidities. Both groups were tracked until a diagnosis of infertility was recorded. The Chi-square test was used to analyze the distribution of demographic characteristics in the HPV group and non-HPV group. A Cox proportional hazards regression was used to estimate the hazard ratios (HRs) for the development of infertility, adjusting for age, sex, and co-morbidities. The Kaplan–Meier method was used to plot the cumulative incidence curves. We also performed negative controls to test for possible unmeasured confounding. Results. The HPV cohort had a higher risk of infertility. The adjusted HR (aHR) was found to be 1.39 (95% CI = 1.19–1.63) after adjusting for demographic characteristics and relevant co-morbidities. In the age subgroup analysis, patients with an HPV infection had an increased risk of infertility compared to the non-HPV cohort in the group aged 26 to 35 years (aHR, 1.53; 95% CI = 1.24–1.88). As we used propensity score matching to treat measurable confounders and negative controls to access unmeasured confounders, the findings of the study are robust. Conclusions. Among females of reproductive age, HPV infection is a potential risk factor that predisposes individuals to subsequent infertility.

Viruses in the reproductive tract: On their way to the germ line?

Studies of vertebrate genomes have indicated that all species contain in their chromosomes stretches of DNA with sequence similarity to viral genomes. How such 'endogenous' viral elements (EVEs) ended up in host genomes is usually explained in general terms such as 'they entered the germ line at some point during evolution'. This seems a correct statement, but is also rather imprecise. The vast number of endogenous viral sequences suggest that common routes to the 'germ line' may exist, as relying on chance alone may not easily explain the abundance of EVEs in modern mammalian genomes. An increasing number of virus types have been detected in human semen and a growing number of studies have reported on viral infections that cause male infertility or subfertility and on viral infections that threaten in vitro fertilisation practices. Thus, it is timely to survey the pathway(s) that viruses can use to gain access to the human germ line. Embryo transfer and semen quality studies in livestock form another source of relevant information because virus infection during reproduction is clearly unwanted, as is the case for the human situation. In this review, studies on viruses in the male and female reproductive tract and in the early embryo will be discussed to propose a plausible viral route to the mammalian germ line.

High-risk human papillomavirus in semen is associated with poor sperm progressive motility and a high sperm DNA fragmentation index in infertile men

STUDY QUESTION

Does the presence of human papillomavirus (HPV) in semen impact seminal parameters and sperm DNA quality in white European men seeking medical help for primary couple's infertility?

SUMMARY ANSWER

HPV seminal infections involving high-risk (HR) genotypes are associated with impaired sperm progressive motility and sperm DNA fragmentation (SDF) values.

WHAT IS KNOWN ALREADY

HPV is commonly present in semen samples. However, whether the presence of HPV in semen is actually associated with impaired sperm parameters and SDF values have yet to be elucidated.

STUDY DESIGN, SIZE, DURATION

In this cross-sectional study, complete demographic, clinical and laboratory data from 729 infertile men were analysed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Health-significant comorbidities were scored with the Charlson comorbidity index (CCI). Serum hormones and SDF index (measured by the sperm chromatin structure assay [SCSA]) were measured in every patient (SDF ≥30% was defined as pathological). Semen analysis was based on 2010 World Health Organisation reference criteria. Amplification by nested PCR was used to detect HPV-DNA sequences in semen samples. Descriptive statistics and linear regression models were used to test the association between the presence of HPV and clinical and seminal characteristics in the whole cohort.

MAIN RESULTS AND THE ROLE OF CHANCE

The overall rate of HPV positivity was 15.5% (113/729). Overall, 78/729 (10.7%) and 35/729 (4.8%) patients had HR HPV+ and low-risk HPV+, respectively. HPV16 was the most prevalent type (22.1%), followed by HPV43 (10.6%), HPV56 and HPV42 (both 8.8%). No differences were found in terms of clinical and hormonal characteristics between patients with or without seminal HPV. Sperm progressive motility was significantly lower (P = 0.01) while SDF values were higher (P = 0.005) in HPV+ men compared to those with no HPV. In particular, HR HPV+ men had lower sperm progressive motility (P = 0.007) and higher SDF values (P = 0.003) than those with a negative HPV test. Univariable analysis showed that HR HPV+ was associated with impaired sperm progressive motility (P = 0.002) and SDF values (P = 0.003). In the multivariable analysis, age, FSH levels and testicular volume were significantly associated with impaired sperm progressive motility (all P ≤ 0.04). Conversely BMI, CCI, smoking habits and HPV status were not. Only age (P = 0.02) and FSH (P = 0.01) were significantly associated with SDF, after accounting for BMI, CCI, testicular volume, smoking habits and HPV status.

LIMITATIONS, REASONS FOR CAUTION

Main limitations are the cross-sectional design of our study and the relatively small sample size of the subgroups. Additional limitations are the lack of a control group of normal fertile men and the lack of follow-up testing to check the clearance or the persistence of HPV in semen after a 6-12 months.

WIDER IMPLICATIONS OF THE FINDINGS

Overall, these observations point out the importance of an accurate investigation of seminal HPV presence in everyday clinical practice in the diagnostic work-up of infertile men.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used. There are no competing interests.

HPV Infection Affects Human Sperm Functionality by Inhibition of Aquaporin-8

Human sperm cells express different aquaporins (AQPs), AQP3, 7, 8, 11, which are localized both in the plasma membrane and in intracellular structures. Besides cell volume regulation and end stage of cytoplasm removal during sperm maturation, the role of AQPs extends also to reactive oxygen species (ROS) elimination. Moreover, oxidative stress has been shown to inhibit AQP-mediated H₂O₂ permeability. A decrease in AQPs functionality is related to a decrease in sperm cells number and motility. Here we investigate the possible effect of human Papillomavirus (HPV) on both expression and function of AQPs in human sperm cells of patients undergoing infertility couple evaluation. Stopped-flow light-scattering experiments demonstrated that HPV infection heavily reduced water permeability of sperm cells in normospermic samples. Confocal immunofluorescence experiments showed a colocalization of HPV L1 protein with AQP8 (Pearson’s correlation coefficient of 0.61), confirmed by co-immunoprecipitation experiments. No interaction of HPV with AQP3 and AQP7 was observed. A 3D model simulation of L1 protein and AQP8 interaction was also performed. Present findings may suggest that HPV infection directly inhibits AQP8 functionality and probably makes sperm cells more sensitive to oxidative stress.

Impact of human papillomavirus infection in semen on sperm progressive motility in infertile men: a systematic review and meta-analysis

BACKGROUND

Human papillomavirus (HPV) has been considered as one of the most common sexually transmitted viruses that may be linked to unexplained infertility in men. The possible mechanisms underlying correlation between HPV infection and infertility could be related to the altered sperm parameters. Current studies have investigated the effect of HPV seminal infection on sperm quality in infertile men, but have shown inconsistent results.

METHODS

We systematically searched PubMed, Embase, Web of Science and CNKI for studies that examined the association between HPV seminal infection and sperm progressive motility. Data were pooled using a random-effects model. Outcomes were the sperm progressive motility rate. Results are expressed as standardised mean difference (SMD) with 95% confidence interval (CI). Heterogeneity was evaluated by the I-square (I²) statistic.

RESULTS

Ten studies were identified, including 616 infertile patients with HPV seminal infection and 2029 infertile controls without HPV seminal infection. Our meta-analysis results indicated that sperm progressive motility was significantly reduced in HPV-infected semen samples compared with non-infected groups [SMD:-0.88, 95% CI:-1.17 ~ - 0.59]. There existed statistical heterogeneity (I² value: 86%) and the subgroup analysis suggested that study region might be the causes of heterogeneity.

CONCLUSIONS

HPV semen infection could significantly reduce sperm progressive motility in infertile individuals. There were some limitations in the study such as the differences in age, sample sizes and the number of HPV genotypes detected. Further evidences are needed to better elucidate the relationship between HPV seminal infection and sperm quality.

HPV infection in semen: results from a new molecular approach

Human papillomavirus (HPV) is the agent of the most common sexually transmitted diseases causing a variety of clinical manifestations ranging from warts to cancer. Oncogenic HPV infection is the major cause of cervical cancer and less frequently of penile cancers. Its presence in semen is widely known, but the effects on fertility are still controversial. We developed a new approach to evaluate virus localisation in the different semen components. We analysed also the specific genotype localisation and viral DNA quantity by qPCR. Results show that HPV DNA can be identified in every fraction of semen: spermatozoa, somatic cells and seminal plasma. Different samples can contain the HPV DNA in different fractions and several HPV genotypes can be found in the same fraction. Additionally, different fractions may contain multiple HPV genotypes in different relative quantity. We analysed the wholeness of HPV DNA in sperm cells by qPCR. In one sample more than half of viral genomes were defective, suggesting a possible recombination event. The new method allows to easily distinguish different sperm infections and to observe the possible effects on semen. The data support the proposed role of HPV in decreased fertility and prompt new possible consequences of the infection in semen.

High rate of detection of ultrasound signs of prostatitis in patients with HPV-DNA persistence on semen: role of ultrasound in HPV-related male accessory gland infection

BACKGROUND

Papillomavirus (HPV) often occurs in the semen of patients with male accessory gland infection (MAGI). Ultrasound (US) evaluation has been suggested as a promising diagnostic tool for patients with HPV-related MAGI. No data on the spontaneous clearance of HPV-DNA have been reported so far in HPV-related MAGI.

PURPOSE

The primary aim of the study was to assess the percentage of early HPV-DNA spontaneous clearance in patients with prostatitis. The secondary aim was to evaluate the frequency of spontaneous clearance of HPV-DNA among patients with prostatitis associated with the presence or absence of US abnormalities.

METHODS

Patients with inflammatory MAGI and at least one suspicious criterion for HPV infection underwent semen HPV-DNA detection and prostate US. The presence of HPV-DNA was further investigated after a 6-month-long follow-up.

MAIN RESULTS

Eighty patients satisfied the inclusion criteria and were recruited in the study. 69% of patients (55/80) showed HPV-DNA persistence in the semen. Among them, 82% (45/55) was positive for US signs of prostatitis, while they occurred only in 12% (3/25) of those patients with no sign of HPV-DNA persistence (p < 0.001). All patients with persistent high-risk HPV genotype (n = 30) showed at least two US signs of prostatitis. In 73% of patients (22/30), E6 and E7 mRNAs were detected.

CONCLUSION

US signs of prostatitis more frequently occurred in patients with evidence of HPV-DNA persistence on semen, especially in those with high-risk genotypes. This highlights the importance of US in the framework of HPV-related MAGI.

Prevalence of human papillomavirus (HPV) in the semen of patients submitted to assisted reproductive technology treatment in a private clinic in Brazil

Objective:

The aim of our study was to identify the prevalence of HPV in the semen of men submitted to ART treatment and look into the possible impacts of the virus on sperm parameters.

Methods:

Thirty-five patients treated for infertility from March to August 2016 were invited to join the study. Samples with a minimum concentration of 40x10⁶ spermatozoa per milliliter were included in the study. After the evaluation of semen parameters, DNA extraction and PCR were performed to verify the presence of HPV by electrophoresis in 8% polyacrylamide gel.

Results:

Patient age ranged from 27 to 68 years (mean 39.2 years). Semen analysis showed a mean volume of 2.5mL; mean concentration of 58.9x10⁶; and mean motility of 51.8%. HPV DNA was identified in seven semen samples from 25 patients (28%). Ten samples with DNA concentrations below 10ng/µL were excluded from the study due to poor amplification quality. There was no statistical difference in sperm concentration when HPV-negative and HPV-positive samples were compared (65.9x10⁶ vs. 62.3x10⁶; p=0.70). However, sperm motility was significantly higher in HPV-positive semen (65% vs. 46.6%; p=0.02).

Conclusions:

HPV prevalence was 28% in the semen of patients submitted to ART treatment. HPV-positive samples had statistically increased motility compared to negative samples (65% vs. 46.6%; p=0.02).

Viral threat to male fertility

The detrimental effects of Zika virus (ZIKV) infection on mouse testicular functions have reminded a viral threat to male fertility. A broad range of virus families has tropism for male reproductive system, particularly the testes. Certain virus types of these viruses, such as mumps virus and human immunodeficiency virus (HIV), may severely damage the testes and consequently lead to male infertility. ZIKV has been recently found to damage testicular functions and lead to male infertility in mice. Many other viruses also have detrimental effects on host reproduction. Public attention has been paid to sexually transmitted viruses, such as HIV and hepatitis B and C viruses in humans and likewise in economically important farm animals. This article provides an overview on main viruses affecting the male reproductive system and their detrimental effects on fertility, and outlines some important issues for future study.

Sperm success and immunity

The moment of the fertilization of an egg by a spermatozoon-the point of "sperm success"-is a key milestone in the biology of sexually reproducing species and is a fundamental requirement for offspring production. Fertilization also represents the culmination of a suite of sexually selected processes in both sexes and is commonly used as a landmark to measure reproductive success. Sperm success is heavily dependent upon interactions with other key aspects of male and female biology, with the immune system among the most important. The immune system is vital to maintaining health in both sexes; however, immune reactions can also have antagonistic effects on sperm success. The effects of immunity on sperm success are diverse, and may include trade-offs in the male between investment in the production or protection of sperm, as well as more direct, hostile, immune responses to sperm within the female, and potentially the male, reproductive tract. Here, we review current understanding of where the biology of immunity and sperm meet, and identify the gaps in our knowledge.

Semen quality is affected by HLA class I alleles together with sexually transmitted diseases

BACKGROUND

The human leukocyte antigen (HLA) locus includes several genes with key roles in antigen presentation and immune response, some of them inclusively found to be associated with non-obstructive azoospermia. Still, HLA connections to other infertility phenotypes such as semen hyperviscosity (SHV), asthenozoospermia (AST), and oligozoospermia (OLI) have been often neglected.

OBJECTIVES

In this work, we aimed to evaluate the association of HLA class I and II genes with SHV, AST, and OLI phenotypes while exploring a possible role in an adaptive immune response to sexually transmitted diseases (STD).

MATERIALS AND METHODS

Whole-exome sequencing was performed in a Portuguese cohort of 71 infertility cases and 68 controls, followed by HLA typing using a specific software-HLA*PRG:LA tool. Molecular screenings of seven STD were carried out in a subset of 72 samples (30 cases and 42 controls).

RESULTS

Statistical tests uncovered three protective alleles: HLA-A*11:01, associated with all forms of male infertility (p = 0.0006); HLA-DQB1*03:02 with SHV and OLI (P_SHV   = 0.0303, P_OLI   = 0.0153); and HLA-A*29:02 with OLI (p = 0.0355), which was found to interfere in sperm number together with HPV (p = 0.0313). Five risk alleles were also identified: two linked with SHV (HLA-B*50:01, p = 0.0278; and HLA-C*06:02, p = 0.0461), another one with both SHV and OLI (HLA-DQA1*05:01, P_SHV   = 0.0444 and P_OLI =0.0265), and two with OLI (HLA-C*03:03, p = 0.0480; and HLA-DQB1*03:01, p = 0.0499). Here, HLA-C*03:03 carriers tend to be HPV infected.

CONCLUSIONS

The application of HLA*PRG:LA tool to the study of male infertility provided novel insights for an HLA correlation with semen quality, namely among SHV and OLI phenotypes. The discovery of an HLA-A*29:02/HPV crosstalk, together with former reports of HLA alleles conferring resistance-susceptibility to diverse human pathogens, raises the hypothesis of a mechanistic link between male infertility, HLA polymorphism, and host response to STD.

Seminal human papillomavirus originates from the body surface and is not a frequent aetiological factor in azoospermia

Human papillomavirus (HPV) DNA has been detected in the testis tissue of 6.5% of 185 men with non‐obstructive azoospermia (NOA). Others have suggested that seminal HPV originates from contamination from the genital skin and mucosa. One hundred unselected azoospermic men and 43 normal men undergoing vasectomy were recruited. Testicular biopsies for HPV examination were collected from all the men. Additionally, the normal men undergoing vasectomy delivered a semen sample and had a swab for HPV examination taken from the genital skin before vasectomy. A piece of each Vas deferens obtained during the vasectomy was examined for the presence of HPV. Two of the primarily azoospermic men were shown to have cryptozoospermia. It was not possible to detect HPV in the testis tissue of any of the included 98 azoospermic men or the 43 proven fertile men. In the proven fertile men, HPV DNA was detected in the semen of 15 men (35%), on the genital skin of 28 men (65%), and in the Vas deferens in three cases (7%). In 13 (87%) men with HPV‐positive semen samples, HPV DNA was also detected in the skin swabs, and in 11 men (73%), identical HPV genotypes were found in the two locations.

Astaxanthin Prevents Human Papillomavirus L1 Protein Binding in Human Sperm Membranes

Astaxanthin (Asta), red pigment of the carotenoid family, is known for its anti-oxidant, anti-cancer, anti-diabetic, and anti-inflammatory properties. In this study, we evaluated the effects of Asta on isolated human sperm in the presence of human papillomavirus (HPV) 16 capsid protein, L1. Sperm, purified by gradient separation, were treated with HPV16-L1 in both a dose and time-dependent manner in the absence or presence of 30 min-Asta pre-incubation. Effects of HPV16-L1 alone after Asta pre-incubation were evaluated by rafts (CTB) and Lyn dislocation, Tyr-phosphorylation (Tyr-P) of the head, percentages of acrosome-reacted cells (ARC) and endogenous reactive oxygen species (ROS) generation. Sperm membranes were also analyzed for the HPV16-L1 content. Results show that HPV16-L1 drastically reduced membrane rearrangement with percentage of sperm showing head CTB and Lyn displacement decreasing from 72% to 15.8%, and from 63.1% to 13.9%, respectively. Accordingly, both Tyr-P of the head and ARC decreased from 68.4% to 10.2%, and from 65.7% to 14.6%, respectively. Asta pre-incubation prevented this drop and restored values of the percentage of ARC up to 40.8%. No alteration was found in either the ROS generation curve or sperm motility. In conclusion, Asta is able to preserve sperm by reducing the amount of HPV16-L1 bound onto membranes.

Human Papilloma Virus (HPV) and Fertilization: A Mini Review

Human papilloma virus (HPV) is one of the most prevalent viral sexually transmitted diseases. The ability of HPV to induce malignancy in the anogenital tract and stomato-pharyngeal cavity is well documented. Moreover, HPV infection may also affect reproductive health and fertility. Although, the impact of HPV on female fertility has not been thoroughly studied it has been found also to have an impact on semen parameters. Relative information can be obtained from studies investigating the relationship between HPV and pregnancy success. Furthermore, there is an ongoing debate whether HPV alters the efficacy of assisted reproductive technologies. An association between HPV and assisted reproductive technologies (ART) programs has been reported. Nevertheless, due to conflicting data and the small number of existing studies further research is required. It remains to be clarified whether HPV detection and genotyping could be included in the diagnostic procedures in couples undergoing in vitro fertilization (IVF)/intrauterine insemination (IUI) treatments. Vaccination of both genders against HPV can reduce the prevalence of HPV infection and eliminate its implications on human fertility. The aim of the present mini-review is to reiterate the association between HPV and human fertility through a systematic literature review.

Effect of human papilloma virus infection on in-vitro fertilization outcome: systematic review and meta-analysis

OBJECTIVES

To identify, appraise and summarize the available data concerning the impact of human papilloma virus (HPV) infection on reproductive outcome following in-vitro fertilization (IVF).

METHODS

We searched for studies in PubMed, EMBASE, Scopus, Lilacs and the Cochrane Central Register of Controlled Trials from inception to March 2017. Any type of HPV infection assessed through polymerase chain reaction, subfertility factors and IVF indications and protocols were considered. Our primary outcomes were live birth/ongoing pregnancy and miscarriage, while secondary outcomes included clinical and laboratory parameters. We planned subgroup analyses according to the status of cervical cytology and presence of infection in the male partner. We assessed the relative risk (RR), using a random-effects model; heterogeneity was assessed using the I² statistic. Quality of the evidence was evaluated using the recommendations of the GRADE Working Group.

RESULTS

From the 14 studies eligible for inclusion, quantitative data from 10, evaluating 299 women with HPV infection and 2049 women without HPV infection, were included in the analysis. The pooled results showed no significant difference between HPV-infected and non-infected women in rates of live birth/ongoing pregnancy (RR, 1.16 (95% CI, 0.88-1.53); I²  = 0%; six studies, 983 women), clinical pregnancy (RR, 1.06 (95% CI, 0.74-1.54); I²  = 61%; eight studies, 1173 women) or miscarriage (RR, 1.58 (95% CI, 0.93-2.69); I²  = 8%; six studies, 290 clinical pregnancies). The overall quality of the evidence was very low, downgraded two levels because of serious limitations of the included studies (observational studies) and imprecision. In contrast, pooled results in the subgroup analysis based on the presence of infection in the male partner showed significant differences in rates of live birth/ongoing pregnancy (RR, 0.43 (95% CI, 0.23-0.82); I²  = 0%; three studies, 429 participants; P = 0.01) and miscarriage (RR, 3.70 (95% CI, 1.94-7.05); I²  = 0%; two studies, 90 participants; P < 0.0001).

CONCLUSIONS

The available evidence is still inadequate to enable us to draw firm conclusions regarding the effect of HPV infection in women on the most important reproductive outcomes following IVF; however, it suggests that the effect is not large for rates of live birth/ongoing pregnancy and clinical pregnancy. When infection is present in the male partner, it seems that there is a negative effect on live birth/ongoing pregnancy rate and an increase in miscarriage rate, a finding that should be interpreted with caution, owing to the very low quality of evidence supporting it. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Human papillomavirus in semen and the risk for male infertility: a systematic review and meta-analysis

Background

Human papillomavirus (HPV) is one of the most prevalent sexually transmitted viruses. Despite the increasing evidence of HPV prevalence in semen, the worldwide distribution of HPV types in semen and risk for male infertility remain inconclusive.

Methods

Four electronic databases were searched for English language studies conducted between January 1990 and December 2016 that reported HPV DNA prevalence in semen. Based on the PRISMA guidelines, HPV prevalence was estimated among general population and fertility clinic attendees, respectively, and heterogeneity testing was performed using Cochran’s Q and I² statistics. The association between HPV positivity and male infertility was evaluated by a meta-analysis of case-control studies.

Results

A total of 31 eligible studies comprising 5194 males were included. The overall prevalence of HPV DNA in semen was 11.4% (95% CI = 7.8-15.0%) in general population (n = 2122) and 20.4% (95% CI = 16.2-24.6%) in fertility clinic attendees (n = 3072). High-risk type prevalence was 10.0% (95% CI = 5.9-14.0%) and 15.5% (95% CI = 11.4-19.7%), respectively. HPV16 was the most common type, with a prevalence of 4.8% (95% CI = 1.7-7.8%) in general population and 6.0% (95% CI = 3.8-8.2%) in fertility clinic attendees. A significantly increased risk of infertility was found for males with HPV positivity in semen (OR = 2.93, 95% CI = 2.03-4.24).

Conclusions

Seminal HPV infection is common worldwide, which may contribute to the risk of male infertility.

Electronic supplementary material

The online version of this article (10.1186/s12879-017-2812-z) contains supplementary material, which is available to authorized users.

Male Partners of Infertile Couples with Seminal Infections of Human Papillomavirus Have Impaired Fertility Parameters

Several studies have addressed the impact of viral infections on male infertility. However, it is still unknown whether human papillomavirus (HPV) can alter seminal parameters. The aim of this study was to determine the prevalence of HPV in the semen of male partners of couples seeking fertility evaluation. Additionally, we assessed the possibility that HPV infections affect seminal parameters. A total of 229 semen samples were collected from men in the Sperm Analysis Section of São Camilo Laboratory of Maringá, Brazil, between October 2015 and March 2016. Basic seminal parameters were analyzed, and HPV was detected and genotyped by polymerase chain reaction. HPV DNA was detected in 16.6% of samples. Of these, 10.5% had single type HPV infections, 6.1% had multiple HPV infections, 5.7% had exclusively high-risk HPV, and 6.1% had exclusively low-risk HPV. Samples positive for single and multiple types of HPV were associated with abnormal viscosity, and samples positive for multiple HPV types were also associated with hypospermia, higher pH, and increased leukocyte numbers. These findings suggest that the male partners of infertile couples with seminal HPV infections may have prostate disturbances indicative of glandular dysfunction, which may influence fertility.

Overview of the benefits and potential issues of the nonavalent HPV vaccine

HPV-related diseases affect anogenital and oropharyngeal regions, heavily affecting the psychosexual dimension of both male and female individuals. HPV vaccination programs based on a bivalent or quadrivalent vaccine have opened broad perspectives for primary prevention. A nonavalent HPV vaccine (9vHPV), covering nine genotypes (HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58), might provide further improvement in terms of direct protection. In the present report, efficacy and safety data from 9vHPV vaccine development programs are examined. Efficacy data come from a pivotal trial, which was conducted among women aged 16-26 years randomly assigned to receive either the 9vHPV or the quadrivalent HPV (4vHPV) vaccine. The 9vHPV vaccine was shown to have potential benefits as compared with 4vHPV, increasing the overall estimated rate of prevention to 90% for cervical cancer and up to 80% for precancerous cervical lesions. For all other HPV-related pre-invasive and invasive lesions, 9vHPV showed potentially greater disease reduction, depending on the anatomic region examined. Thus, the 9vHPV vaccine shows clinical potential for the prevention of HPV-related diseases in both sexes. Future adoption of 9vHPV will depend on factors including market price, cost-effectiveness data, use of a two-dose schedule, and safety and efficacy monitoring in real-life programs.

Presence of human papillomavirus in semen in relation to semen quality

STUDY QUESTION

Is the presence of human papillomavirus (HPV) in semen associated with impairment of semen quality?

SUMMARY ANSWER

In a large cohort of males seeking fertility evaluation, no associations were observed between seminal HPV presence and semen parameters.

WHAT IS KNOWN ALREADY

HPV is commonly detected in semen samples. Whether the presence of HPV is related to impairment of semen quality, remains unclear.

STUDY DESIGN, SIZE, DURATION

This cross-sectional study included a cohort of 430 males.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Male partners in couples seeking fertility evaluation provided one semen sample per person. Semen samples were tested for HPV-DNA using GP5+/6+-PCR. Sperm concentration was counted and motility was assessed in a Makler counting chamber at a magnification of ×200. The presence of antisperm antibodies was assessed by a mixed agglutination reaction (MAR)-test.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall HPV was detected in 14.9% (64/430) of semen samples, including 2.1% (9/430) that contained both high-risk (hr) HPV and low-risk (lr) HPV types, 8.8% (38/430) with exclusively hrHPV types and 4.0% (17/430) with exclusively lrHPV types. The presence of HPV in semen was not associated with the age of the participants, seminal pH, semen volume, total sperm count, sperm concentration, progressive motility or the presence of antisperm antibodies.

LIMITATIONS, REASONS FOR CAUTION

This study did not observe an association between HPV presence in semen and impairment of semen quality. However, we cannot exclude an effect of seminal HPV on early embryo development and clinical reproductive outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

As HPV is frequently present in semen, screening of donor semen for HPV should be considered to prevent iatrogenic cervical HPV infections in the recipient. However our findings do not support standardized HPV testing of semen in the diagnostic work-up of subfertile couples.

STUDY FUNDING/COMPETING INTERESTS

This study was sponsored by an unrestricted grant of Stichting Researchfonds Pathology Amsterdam, the Netherlands. P.J.F.S. has been on the speakers bureau of Roche, Gen-Probe, Abbott, Qiagen and Seegene and has been a consultant for Crucell B.V. J.B. has been on the speakers bureau of Qiagen and has been a consultant for Roche, DDL Diagnostic Laboratory, GlaxoSmithKline and Merck. D.A.M.H. has been member of the scientific advisory boards of Amgen and Pfizer, and has been on the speakers bureau of Hologic/Gen-Probe. C.J.L.M.M. has been on the speakers bureau of GlaxoSmithKline, Qiagen, Merck, Roche, Menarini and Seegene, has served occasionally on the scientific advisory board of GlaxoSmithKline, Qiagen, Merck, Roche and Genticel, and has occasionally been a consultant for Qiagen. Formerly, C.J.L.M.M. was a minority shareholder of Delphi Biosciences, which bankrupted in 2014. C.J.L.M.M. is a minority shareholder of Diassay B.V. P.J.F.S., D.A.M.H. and C.J.L.M.M. have minority stake in Self-Screen B.V., a spin-off company of VU University Medical Center. R.L., M.G.D., P.G.A.H., D.T.M.P., and I.H. do not have any conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

Not applicable.

TLR signalling affects sperm mitochondrial function and motility via phosphatidylinositol 3-kinase and glycogen synthase kinase-3α

Infection in male and female genital tracts can lead to infertility. The underlying mechanisms of this process remain unclear. Toll-like receptors (TLRs) recognize conserved structures and respond to pathogens by initiating signals that activate inflammatory gene transcription. Here, we demonstrate that TLR activation in sperm reduces sperm motility via signalling through myeloid differentiation factor 88 (MyD88), phosphatidylinositol 3-kinase (PI3K), and glycogen synthase kinase (GSK)-3α. Upon TLR activation, phosphorylated forms of PI3K and GSK3α were detected in the mitochondria, and the mitochondrial membrane potential was impaired in sperm. In addition, mitochondrial ATP levels were decreased after TLR agonist stimulation. Furthermore, blocking PI3K or GSK3α activation abrogated these effects and reversed the TLR-induced reduction in sperm motility. These results identify a previously unrecognized TLR signalling pathway that leads to dysfunctional sperm mitochondria, which reduce sperm motility. Our study reveals a novel mechanism by which pathogenic infection affects sperm motility and possibly leads to infertility.

Human Papillomavirus Infection, Infertility, and Assisted Reproductive Outcomes

The human papillomavirus (HPV) is a sexually transmitted infection common among men and women across all geographic and socioeconomic subgroups worldwide. Recent evidence suggests that HPV infection may affect fertility and alter the efficacy of assisted reproductive technologies. In men, HPV infection can affect sperm parameters, specifically motility. HPV-infected sperm can transmit viral DNA to oocytes, which may be expressed in the developing blastocyst. HPV can increase trophoblastic apoptosis and reduce the endometrial implantation of trophoblastic cells, thus increasing the theoretical risk of miscarriage. Vertical transmission of HPV during pregnancy may be involved in the pathophysiology of preterm rupture of membranes and spontaneous preterm birth. In patients undergoing intrauterine insemination for idiopathic infertility, HPV infection confers a lower pregnancy rate. In contrast, the evidence regarding any detrimental impact of HPV infection on IVF outcomes is inconclusive. It has been suggested that vaccination could potentially counter HPV-related sperm impairment, trophoblastic apoptosis, and spontaneous miscarriages; however, these conclusions are based on in vitro studies rather than large-scale epidemiological studies. Improvement in the understanding of HPV sperm infection mechanisms and HPV transmission into the oocyte and developing blastocyst may help explain idiopathic causes of infertility and miscarriage.

Human papillomavirus infection and fertility alteration: a systematic review

Background

HPV is the most prevalent sexually transmitted infection and its effect in cancer induction is well documented. HPV infections are mostly asymptomatic, but it is unclear whether HPV infections can result in alterations of reproductive health.

Objective

To determine the relationship between human papillomavirus infections and reproductive health in both men and women.

Methods

A systematic literature review was performed in PubMed and ScienceDirect data bases from January 1994 through August 2014.

Results

HPV infections are shown to be significantly associated to many adverse effects in the reproductive function. These adverse effects were reported in different levels from cells production to pregnancy and may be related to the infecting genotype.

Conclusions

It appears from this study that HPV detection and genotyping could be of great value in infertility diagnosis at least in idiopathic infertility cases. Like for the risk of carcinogenesis, another classification of HPV regarding the risk of fertility alteration may be considered after deep investigations.

Male infertility: a public health issue caused by sexually transmitted pathogens

Sexually transmitted diseases (STDs) are caused by several pathogens, including bacteria, viruses and protozoa, and can induce male infertility through multiple pathophysiological mechanisms. Additionally, horizontal transmission of STD pathogens to sexual partners or vertical transmission to fetuses and neonates is possible. Chlamydia trachomatis, Ureaplasma spp., human papillomavirus, hepatitis B and hepatitis C viruses, HIV-1 and human cytomegalovirus have all been detected in semen from symptomatic and asymptomatic men with testicular, accessory gland and urethral infections. These pathogens are associated with poor sperm quality and decreased sperm concentration and motility. However, the effects of these STD agents on semen quality are unclear, as are the effects of herpes simplex virus type 1 and type 2, Neisseria gonorrhoeae, Mycoplasma spp., Treponema pallidum and Trichomonas vaginalis, because few studies have evaluated the influence of these pathogens on male infertility. Chronic or inadequately treated infections seem to be more relevant to infertility than acute infections are, although in many cases the exact aetiological agents remain unknown.

HPV-DNA sperm infection and infertility: from a systematic literature review to a possible clinical management proposal

The objectives of this study were to investigate the implications of human papillomavirus (HPV) sperm infection on male fertility, impairment of sperm parameters, and possible alteration of sperm nuclear status and to identify a possible effective management of infertile men with HPV sperm infection. We employed a systematic review and clinical management proposal at the Centers for Reproductive and Health care for treating infertile male patients with HPV infection. Literature search was carried out in electronic databases in the last two decades. We focused our attention on: (i) HPV sperm prevalence (ii) HPV-related alteration of sperm parameters; (iii) molecular mechanisms of HPV semen infection and infertility. The main outcome measures were HPV prevalence in infertile male patients and semen parameters. The prevalence of HPV sperm infection ranges between 2 and 31% in men from general population and between 10 and 35.7% in men affected by unexplained infertility. The presence of HPV in semen is associated with an impairment of sperm motility and the presence of anti-sperm antibodies. The molecular mechanisms underlying impairment of sperm motility apparatus need further evaluations. A greater attention should be applied to assess HPV sperm infection, particularly in men undergoing assisted reproduction techniques cycle for male infertility or sperm banking. It would be useful to perform HPV test and fluorescent in situ hybridization analysis for HPV in semen from these patients both at first admission, to define the possible presence and localization of semen infection, and after 6 months, to assess the possible virus clearance retrieval on normal sperm parameters.