Male and couple fertility impairment due to HPV-DNA sperm infection: update on molecular mechanism and clinical impact--systematic review

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.

Human papillomavirus infection in women undergoing in-vitro fertilization: effects on embryo development kinetics and live birth rate

BACKGROUD

Several studies showed that human papillomavirus (HPV) affects male fertility, but its impact on female fertility and in vitro fertilization (IVF) outcome is not yet clear.

METHODS

Objective of this observational, prospective, cohort study was to evaluate the prevalence of HPV infection in women candidate to IVF, and the effects of HPV infection on the kinetic of embryonic development and on IVF outcome. A total number of 457 women candidate to IVF were submitted to HR-HPV test; among them, 326 underwent their first IVF cycle and were included in the analysis on IVF results.

RESULTS

8.9% of women candidate to IVF were HPV-positive, HPV16 being the most prevalent genotype. Among the infertility causes, endometriosis was significantly more frequent in HPV-positive than in negative women (31.6% vs. 10.1%; p < 0.01). Granulosa and endometrial cells resulted HPV-positive in 61% and 48% of the women having HPV-positive cervical swab, respectively. Comparing HPV-positive and negative women at their first IVF cycle, no significant difference was observed in the responsiveness to controlled ovarian stimulation (COS) in terms of number and maturity of retrieved oocytes, and of fertilization rate. The mean morphological embryo score was comparable in the two groups; embryos of HPV-positive women showed a quicker development in the early stages, with a significantly shorter interval between the appearance of pronuclei and their fusion. In the following days, embryo kinetic was comparable in the two groups until the early blastocyst stage, when embryos of HPV-positive women became significantly slower than those of HPV-negative women. Overall, these differences did not affect live birth rate/started cycle, that was comparable in HPV-positive and negative women (22.2 and 28.1%, respectively).

CONCLUSIONS

(a) the prevalence of HPV infection in women candidate to IVF is similar to that observed in the general female population of the same age range; (b) HPV infection migrates along the female genital apparatus, involving also the endometrium and the ovary, and perhaps participates in the genesis of pelvic endometriosis; (c) HPV slightly affects the developmental kinetic of in vitro-produced embryos, but does not exert an effect on live birth rate.

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.

Human Papillomavirus (HPV) Infection and Its Impact on Male Infertility

Nowadays, the striking numbers of infertile couples that turn to assisted reproductive technologies (ART) drive the research toward a more comprehensive understanding of the underlying causes. Male factors contribute to the inability to conceive in half of the cases, and it has been suggested that sexually transmitted infections could have a role in the onset of spermatozoa impairments. Since the impact of HPV infection on sperm quality and sperm DNA integrity is debated, we wanted to analyze its impact on conventional seminal parameters and the sperm DNA fragmentation index (DFI). Therefore, 117 semen samples of patients undergoing IVF were evaluated for the following characteristics: HPV DNA detection and sperm DNA fragmentation, concentration, motility, and morphology. The results showed a higher rate of HPV-negative patients (59.8% vs. 40.2%) and no HPV-related effect on DFI, sperm concentration, total sperm number, and total motility. Only progressive motility and morphology were found as significantly influenced by HPV positivity. Moreover, we observed a statistically significant difference in DFI when comparing high-risk HPV (HR-HPV) and low-risk HPV (LR-HPV) genotypes. Our data suggest that the presence of any HPV type, whatever the exact localization of the virions, can impair some sperm parameters, while HR-HPVs specifically affect the integrity of spermatozoa DNA.

HPV and vaginal microecological disorders in infertile women: a cross-sectional study in the Chinese population

Background

The purpose of this study was to evaluate the distributions of vaginal microbiome dysbiosis and human papillomavirus (HPV) subtypes in infertile women and explore the correlations of HPV infection and vaginal microbiome dysbiosis with infertility.

Methods

In total, 1464 women aged 18–50 years were included in this study; 649 participants were included in the infertility group, and 815 participants were included in the normal group. The participants were tested for HPV, and their vaginal microecology was examined. The χ² test and Spearman regression were used for statistical analysis, and binary logistic regression was performed to identify the risk factors for infertility.

Results

The patients in the infertility group were younger than those in the normal group, and the proportions of bacterial vaginosis and vaginal imbalance in the infertility group were significantly higher than those in the normal group. The incidence proportions of high-risk HPV types in the infertility group were significantly higher than those in the normal group, and the proportions of high-risk subtytes HPV16, HPV39, HV52, HPV56, and HPV68 were significantly higher in the infertility group than in the normal group. However, there were no significant differences in the incidences of low-risk HPV types. The incidence proportions of vaginal flora imbalance and HPV infection in the infertility group were significantly higher than those in the normal group. HPV16, HPV33, HPV51, HPV52and HPV58 infections were independent risk factors for infertility.

Conclusions

Vaginal microecological imbalance and HPV infection are directly related to infertility, and precautions should be taken.

The Microbiome, an Important Factor That Is Easily Overlooked in Male Infertility

Humankind has been interested in reproduction for millennia. Infertility, in which male factors contribute to approximately 50%, is estimated to concern over 72 million people worldwide. Despite advances in the diagnosis, medical treatment, and psychosocial management of male infertility over the past few decades, approximately 30% of male infertility is still thought to be idiopathic. Despite emerging advances in the microbiome associated with male infertility have indicated that the microbiome may be a key factor to the management of male infertility, roles, and mechanisms of the microbiome remain ambiguous. Here, we mainly discussed the association between microbial infection in the genital tract and male infertility, effect of antimicrobial therapy on male reproduction, association between microbial dysbiosis and male infertility, and effect of probiotic intervention on male reproduction. This review made progress toward establishing a relationship between the microbiome and male infertility, and explored the role of the microbiome in male infertility. We call for more high-quality studies to focus on the relationship between microbes and male infertility, and strongly suggest increasing awareness among sterile males with microbial infection and/or microbial dysbiosis when they seek fertility help.

Association between Human Papillomavirus and Chlamydia trachomatis genital infections in male partners of infertile couples

The prevalence of HPV infection and its relationship with other sexually transmitted infections was analyzed in a cohort of 117 male partners of infertile couples from Cordoba, Argentina. Semen samples and urethral swabs were obtained and the infection with HPV, Chlamydia trachomatis, HSV1, HSV2, Mycoplasma hominis and Ureaplasma urealyticum was analyzed. A prevalence of HPV infection of 27.4% was found. Interestingly, infections by exclusively low risk HPV genotypes or high/intermediate risk HPV genotypes were present in 64.5% and 22.6% of cases, respectively. Low risk-HPV6 was the most frequently detected genotype. Remarkably, HPV and C. trachomatis infections were significantly associated to each other (OR: 11.55, 95% CI 1.14-117.06). No significant differences in sperm quality were found between HPV-positive and HPV-negative patients indicating that HPV male urogenital infection does not impair sperm quality. Our results show a high prevalence of HPV urogenital infection among male partners of infertile couples, and that HPV and C. trachomatis infections are reciprocal risk factors of their co-infection. Moreover, our results suggest that men constitute a reservoir for continued transmission of C. trachomatis and HPV to women highlighting the need for routine screening for these two pathogens in male partners of infertile couples.

Relative frequency of hepatitis B virus, human papilloma virus, Epstein-Barr virus, and herpes simplex viruses in the semen of fertile and infertile men in Shiraz, Iran: A cross-sectional study

Background

About 8-12% of couples on reproductive age suffers from infertility worldwide. Since 1993, the role of genital tract infections by microbes, including viruses that can infect the sperm, in human infertility has been proposed.

Objective

To investigate the frequency of hepatitis B virus (HBV), human papilloma virus (HPV), Epstein-Barr virus (EBV), and herpes simplex virus (HSV) infection in the semen of fertile and infertile men referred to the Mother and Child Hospital, Shiraz, Iran.

Materials and Methods

In this cross-sectional study, 350 men including 200 infertile and 150 fertile men were included. All semen samples were allowed to liquefy, followed by the assessment of sperm parameters. DNA was extracted using a DNA extraction kit (CinaGene, Tehran, Iran) according to the manufacturer's instructions. Detection of HBV, HPV, EBV, and HSV1/2 was done by the PCR method.

Results

The mean age of the participants was 36 ± 7 yr. Molecular results showed that 16 samples (8%) of infertile men and 5 (3.3%) of fertile men were positive for HBV, which was not statistically significant (p = 0.069). Only one sample of the fertile participants was positive for HPV. None of the semen samples of the infertile or fertile groups was positive for the presence of EBV or HSV1/2.

Conclusion

The results of this study indicated that HBV, HPV, EBV, and HSV might not be involved in men's infertility. Further studies are recommended for clarifying the role of these viruses in infertility.

Long-term consequences of sexually transmitted infections on men's sexual function: A systematic review

Objective: To systematically review the available literature on the long-term effects of sexually transmitted diseases (STIs) on male reproductive functions.

Methods: A PubMed search was conducted on 3 January 2021, and as a result, 952 articles were retrieved. Exclusion of irrelevant articles resulted in 36 articles, dating from 1998 to 2020, which were analysed.

Results: Only 52.8% of these articles described original research, while the rest were reviews. The majority (26) of the articles dealt with bacterial infections, of which 20 described Chlamydia trachomatis. There were 11 articles that described research on viruses, with five on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The analysis of the articles showed further that not much new knowledge on the long-term effects on male reproductive functions has been added. The existing knowledge that ascending infections can cause epididymo-orchitis, prostatitis or urethritis was confirmed. Due to epithelial inflammatory responses these infections can result in scarring with resulting infertility due to obstruction. These effects were described for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium or Treponema pallidum, as well as for the Zika and SARS-CoV-2 viruses. Even trichomoniasis can lead to long-term compromised male fertility if not treated.

Conclusion: In conclusion, problem awareness needs to be raised and more research on this important topic needs to be conducted.

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.

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.

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.

HIV, HPV and Chlamydia trachomatis: impacts on male fertility

Sexually transmitted diseases (STDs) are pathologies that have viruses, bacteria, protozoa and fungi as infectious agents, affecting millions of people worldwide and causing physical and psychological consequences for the carrier. Some of these infections such as HIV, HPV and Chlamydia trachomatis may present an asymptomatic phase, making the diagnosis difficult, which is often only performed when the couple looks for infertility treatment after not achieving spontaneous pregnancy. Infertility affects 15% of couples, 50% of cases are male-related, and it is estimated that STDs, which interfere with the physiology of the male reproductive system and may impair semen in parameters such as motility, concentration, morphology and number, cause 15% of male infertility cases. Since STDs treatments are increasing the expectation and quality of life of infected patients, discussing issues such as sexuality and reproduction is of great importance in clarifying unknown facts. This paper aims to discuss how the infectious processes associated with HIV, HPV and Chlamydia trachomatis can interfere with semen quality causing male infertility without apparent cause.

Distribution of Human Papillomavirus and Antisperm Antibody in Semen and Its Association with Semen Parameters Among Infertile Men

BACKGROUND

Sexually transmitted infections (STIs) can be associated with infertility. Human papillomavirus (HPV) has been identified as a potential agent in male infertility. Also, anti-sperm antibodies (ASA) have been detected in men with infertility. The aim of this study was to investigate the prevalence and association of HPV and ASA in infected semen of infertile men.

METHODS

This cross-sectional study was performed on 96 infertile men referring to infertility treatment center of Kashan University of Medical Sciences during March 2017 till September 2017 in Iran. Semen analysis and diagnostic PCR test were performed for detection of HPV DNA. The semen parameters in HPV infected and ASA positive samples were compared with HPV non-infected and ASA negative samples. Chi square test was used to determine the correlation between variables and p<0.05 was considered statistically significant.

RESULTS

HPV DNA and ASA were detected in 17.4% and 15.2% of 96 semen samples, respectively. Semen volume, sperm count, sperm motility and the normal morphology rate were significantly decreased in HPV-positive subjects (p=0.004, p= 0.016, p<0.001, and p=0.017, respectively). Also, sperm motility was significantly decreased in ASA-positive subjects (p=0.002), also patients with HPV infection had a higher rate of ASA than the non-HPV group. In contrast to ASA, HPV infection had a significant correlation with education level (p=0.039).

CONCLUSION

The findings suggest that asymptomatic seminal infection of HPV and ASA by adversely affecting sperm quality, in particular sperm motility and count, may play an important role in male infertility.

Prevalence of human papillomavirus infection in oocyte donors and women treated for infertility: An observational laboratory-based study

Objective

The aims of this study were to determine the prevalence of human papillomavirus (HPV) infection in women treated for infertility and oocyte donors, and to investigate the possible influence of HPV infection on reproductive outcomes.

Study design

In this observational laboratory-based study, cervical swabs were collected from oocyte donors (n = 207), and women treated for infertility (n = 945) and analysed for the presence of high-risk HPV (hrHPV) genotypes using the cobas® 4800 HPV Test and PapilloCheck® HPV-Screening. Associations between hrHPV positive status and fertility outcome or socio-behavioral and health characteristics were evaluated using R statistical software.

Results

HrHPV prevalence was significantly higher in oocyte donors than in women treated for infertility (28.0% vs. 16.1%, P <  0.001). Women who became pregnant spontaneously (19.6%) and women not treated with in vitro fertilization (IVF, 18.1%) were more frequently hrHPV positive than women treated with IVF (12.7%, P = 0.077). Despite the high prevalence of hrHPV in both oocyte donors and infertile women, no associations between hrHPV positive status and pregnancy or abortion rates were found in IVF treated women or in oocyte recipients. Moreover, no associations between hrHPV positive status and abortion rates were found in spontaneously pregnant women.

Conclusion

Despite the high prevalence of hrHPV in both oocyte donors and infertile women, HPV infection did not influence the outcomes of assisted reproductive technology.

Time has come to include Human Papillomavirus (HPV) testing in sperm donor banks

HPV is well known as a potential cause of cervical cancer. Less well known is its link to temporal subfertility that is caused by binding of infectious virions to the spermatozoa's head which induces sperm-DNA damage and causes a reduction in clinical pregnancy rates in women receiving HPV positive semen. This impact on the global fertility burden remains greatly underestimated and underexplored. This risk of reduced fertility due to infectious HPV in sperm is especially important when donor sperm insemination is considered, since testing for the presence of HPV virions before use seems warranted. We tested 514 donor sperm samples from 3 different sperm banks for 18 different HPV types. Overall 3.9% (20/514) of tested donor sperm was positive for HPV, with different prevalence among the 3 different sperm banks (3.6% bank A, 3.1% bank B and 16.7% bank C). Also the HPV virion per spermatozoon ratio in donor samples was similar across the different sperm banks (95% CI 0,01 to 1,07 HPV virions/spermatozoon). When HPV positive donor sperm was used, no clinical pregnancies resulted, whereas when HPV negative donor sperm was used the clinical pregnancy rate was 14.6%. From both a cost/benefit and a safety point of view we recommend that donor sperm should always be tested for HPV before using it for insemination.

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.

Significant Correlation between High-Risk HPV DNA in Semen and Impairment of Sperm Quality in Infertile Men

Background

Human papillomavirus (HPV) is a DNA virus that causes sexually transmitted infections (STI). Recent reports suggest that HPV may affect sperm parameters and lead to male infertility. This study aims to evaluate the cor- relation between seminal high-risk HPV infection and impairment of sperm quality in infertile Iranian men.

Materials and Methods

In this case-control study, we collected fresh semen samples from 70 fertile men and 70 confirmed infertile men who referred to Yazd Infertility Centre in 2015. Semen analyses were performed according to the World Health Organization (WHO) guidelines. High-risk HPV DNA was detected by real-time polymerase chain reaction (PCR).

Results

A total of 140 subjects participated in the current study. Among 70 confirmed infertile males, only 8 (11.43%) cases tested positive for high-risk HPV and all fertile men were HPV-negative. This data revealed a significant asso- ciation between high-risk HPV and male infertility (P=0.03). The percentage of normal sperm morphology and sperm motility rate significantly declined in men infected with HPV (P<0.001).

Conclusion

There was a significantly higher prevalence of high-risk HPV in infertile men than fertile men. HPV infection seemed to be a risk factor for male infertility. Additional, larger studies should be conducted to confirm the impact of HPV on male infertility.

DNA fragmentation index and human papilloma virus in males with previous assisted reproductive technology failures

OBJECTIVE

This study was designed to evaluate the prevalence of Human Papilloma Virus (HPV) in semen and document the cycle outcomes in couples with previous intra-cytoplasmic sperm injection (ICSI) failures.

MATERIAL AND METHODS

One hundred and seventeen couples with at least two ICSI attempts were included in the study. HPV infection in semen and DNA fragmentation in samples were analyzed by commercially available kits. The percentage of spermatozoa with fragmented DNA (DNA fragmentation index: DFI) was determined during fluorescence microscopic examination as previously described. The cycle outcomes of couples with or without HPV infected male partners were recorded.

RESULTS

According to our results, the prevalence of HPV was 7.7% in asymptomatic males with at least two previous ICSI failures. The increased DFI (>30%) was observed in 82.9% of the cases. In HPV-positive cases significantly lower number of good quality embryos were obtained. The implantation and pregnancy rates were similar in infected and non-infected males (p>0.05). The early miscarriage rate was slightly higher in HPV- positive group (33% vs. 10%, p>0.05).

CONCLUSION

In cases with previous ICSI failures, the prevalence of HPV infection in semen is not higher than previously reported infertile populations. The reproductive outcome might be impaired in HPV-positive semen due to lower number of good quality embryos, which needs to be clarified by further large population-based studies.

The implications of male human papilloma virus infection in couples seeking assisted reproduction technologies

Human papilloma virus (HPV) is one of the most common viral sexually-transmitted diseases worldwide. The prevalence of HPV is higher in infertile males when compared with fertile men and ranges between 10 and 35.7% in men affected by unexplained infertility. HPV can bind to spermatozoa and can potentially be transferred to fertilized oocytes. Viral detection in blastocysts and trophoblastic cells is associated with impaired embryo development and poor pregnancy outcomes. Nevertheless, attempts to eliminate HPV-DNA from sperm samples through routine washing techniques have failed. In assisted reproduction technologies (ART), intracytoplasmic sperm injection involves no natural selection of the sperm cell, which means that these procedures have a plausible risk of injecting sperm containing HPV. The possible detrimental effects of HPV on ART in couples with infected male partners are summarized in this 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.

Human Papillomavirus (HPV) virion induced cancer and subfertility, two sides of the same coin

In the natural history of HPV infections, the HPV virions can induce two different pathways, namely the infec- tious virion producing pathway and the clonal transforming pathway. An overview is given of the burden that is associated with HPV infections that can both lead to cervical cancer and/or temporal subfertility. That HPV infections cause serious global health burden due to HPV-associated cancers is common knowledge, but that it is also responsible for a substantial part of idiopathic subfertility is greatly underestimated. The bulk of the detected HPV DNA whether in men or women is however infectious from origin. Because the dissociation between HPV viruses and HPV virions or infection and disease remains difficult for clinicians as well as for HPV detection, we propose a review of the different effects caused by the two different HPV virion induced pathways, and highlight the mechanisms that are responsible for causing transient subfertility and cancer.

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.

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.

Spontaneous fertility and in vitro fertilization outcome: new evidence of human papillomavirus sperm infection

OBJECTIVE

To evaluate the reproductive outcome of infertile couples undergoing assisted reproduction techniques (ART) with or without human papillomavirus (HPV) semen infection.

DESIGN

Cross-sectional clinical study.

SETTING

Units of andrology, reproductive medicine, and gynecology.

PATIENT(S)

A total of 226 infertile couples.

INTERVENTION(S)

Male partners were evaluated by means of fluorescence in situ hybridization (FISH) for HPV on semen. After a diagnostic period, female partners underwent intrauterine insemination (IUI) or intracytoplasmic sperm injection (ICSI).

MAIN OUTCOME MEASURE(S)

Seminal parameters and FISH analysis for HPV in sperm head. Spontaneous or assisted pregnancies, live births, and miscarriages were recorded. Statistical analysis included unpaired Student t test and chi-square test.

RESULT(S)

Fifty-four male partners (23.9%) had HPV semen infection confined to sperm, confined to exfoliated cells, or in both cells. During the diagnostic period, noninfected couples showed spontaneous pregnancies. IUI and ICSI treatments were performed in, respectively, 60 and 98 noninfected and in 21 and 33 infected couples, with 38.4% and 14.2% cumulative pregnancy rates, respectively. The follow-up of pregnancies showed a higher miscarriage rate in infected couples (62.5% vs. 16.7%). Ongoing pregnancies of the latter group were characterized by HPV infection confined to exfoliated cells.

CONCLUSION(S)

A reduction in natural and assisted cumulative pregnancy rate and an increase in miscarriage rate are related to the presence of HPV at sperm level. Although the exact mechanism by which sperm infection is able to impair fertility remains unclear, this aspect is worthy of further investigations. If confirmed, these results could change the clinical and diagnostic approach to infertile couples.

Activation of Toll like receptor 3 induces spermatogonial stem cell apoptosis

Germ cell apoptosis may be associated with the male infertility. The pathogenesis is to be further understood. Viral infection is one of the causative factors of apoptosis of the body cells. This study aims to investigate the role of activation of Toll like receptor (TLR)3 in the induction of germ cell apoptosis. In this study, spermatogonial stem cells (SSC) were isolated from C57BL/6 mouse testes. The expression of TLR3 on SSC was by RT-qPCR and Western blotting. polyinosinic-polycytidylic acid (Poly I:C) was employed to activate TLR3 on SSCs. The results showed that re-activation by PolyI:C induced SSC apoptosis. Exposure to PolyI:C induced interferon regulatory factor 3 (IRF3) phosphorylation in SSCs. TLR3 and IRF3 formed a complex in the SSCs. The complex of TLR3/IRF3 bound to the promoter of Fas ligand and promoted Fas ligand expression in SSC, and thus induced SSC apoptosis. In conclusion, the results of the present study indicate that activation of TLR3 by PolyI:C induces the SSC apoptosis, which implies that viral infection may interfere with the male germ cell development.

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.

Molecular and cellular mechanisms of sperm-oocyte interactions opinions relative to in vitro fertilization (IVF)

One of the biggest prerequisites for pregnancy is the fertilization step, where a human haploid spermatozoon interacts and penetrates one haploid oocyte in order to produce the diploid zygote. Although fertilization is defined by the presence of two pronuclei and the extraction of the second polar body the process itself requires preparation of both gametes for fertilization to take place at a specific time. These preparations include a number of consecutive biochemical and molecular events with the help of specific molecules and with the consequential interaction between the two gametes. These events take place at three different levels and in a precise order, where the moving spermatozoon penetrates (a) the outer vestments of the oocyte, known as the cumulus cell layer; (b) the zona pellucida (ZP); where exocytosis of the acrosome contents take place and (c) direct interaction of the spermatozoon with the plasma membrane of the oocyte, which involves a firm adhesion of the head of the spermatozoon with the oocyte plasma membrane that culminates with the fusion of both sperm and oocyte membranes (Part I). After the above interactions, a cascade of molecular signal transductions is initiated which results in oocyte activation. Soon after the entry of the first spermatozoon into the oocyte and oocyte activation, the oocyte’s coat (the ZP) and the oocyte’s plasma membrane seem to change quickly in order to initiate a fast block to a second spermatozoon (Part II). Sometimes, two spermatozoa fuse with one oocyte, an incidence of 1%–2%, resulting in polyploid fetuses that account for up to 10%–20% of spontaneously aborted human conceptuses. The present review aims to focus on the first part of the human sperm and oocyte interactions, emphasizing the latest molecular and cellular mechanisms controlling this process.

Is it time to shift the attention on early stages embryo development to avoid inconclusive evidence on HPV-related infertility: debate and proposal

BACKGROUND

Current evidence about in-vivo effects of HPV cannot definitively clarify the possible negative role of this worldwide common infection in early embryo development. However in-vitro evidence, seems to underline a possible negative effect of HPV in increasing blastocyst apoptosis and in reducing the endometrial implantation of trophoblastic cells. On these bases we believe that a new scientific approach is necessary to better understand the real role of male and female HPV infection in infertility and early pregnancy development.

METHODS

English literature review of manuscripts focused on HPV infection and human reproduction was conducted. We performed a critical analysis of evidence and possible bias affecting both in-vivo and in-vitro studies regarding this topic.

RESULTS

The biggest limitation of the in-vivo studies is due to the inappropriate timing of HPV effects evaluation since evidence about in-vitro studies strongly suggests that a large part of HPV negative effects occurs during a very early stage of embryo development. All the efforts of the scientific community to investigate the real role of HPV in human reproduction disorders cannot underestimate the severe BIAS of actual evidence in postulating new hypothesis and research projects which are fundamental to clarify if HPV may be associated with unexplained couples infertility and early miscarriages.

CONCLUSIONS

If the relationship between HPV gametes infection and early human reproduction step impairment will be confirmed, the HPV male and couple vaccination may represent a reliable option to improve fertility in some couples affected by infertility actually classified as "idiopathic" but maybe linked to HPV infection.