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.

The impact of cryopreservation on both sperm HPV-negative and positive subtypes

It is well known that various human papillomavirus (HPV) genotypes are present in semen specimens. Also, it has been demonstrated that sperm parameters are negatively affected when HPV infection is present in the sperm sample. Besides all these, the effect of cryopreservation on HPV sensitivity and resistance is not known. The aim of the present study is to evaluate first the prevalence of HPV and secondly to elucidate whether cryopreservation of sperm HPV-positive samples has any effect on the viability of HPV. For this purpose, a cohort of 78 sperm specimens was used from a respective number of patients. After giving informed consent, semen analysis was performed. Each sperm sample was divided into four equal aliquots. The first one (fresh) was evaluated for the prevalence of HPV, while the other three aliquots were cryopreserved by adding an equal quantity of cryoprotectant and plunged into the LN. Each of the three aliquots was thawed 3, 6, and 12 months later, respectively, so as to evaluate whether there is a time-resistance period of HPV prevalence. HPV infection was found to be in eleven sperm samples, demonstrating a 14.1% (11/78) HPV prevalence. Among the HPV-positive samples, six of them were high-risk and the remaining were low-risk genotypes. Moreover, the high-risk fresh samples demonstrated higher motility values than the low-risk samples (60% ± 2.7 vs 45.6% ± 3.7, p < .05), while semen volume in the high-risk samples was significantly lower than the respective volume in the low-risk samples (2.26 ± 0.2ml vs 3.5 ± 0.6ml, p < .05). Interestingly, cryopreservation of the HPV-positive samples resulted in the sustainability and time-resistance of HPV in all high-risk HPV-positive samples, something that was not the case with the low-risk HPV-positive samples. Conclusively, sperm samples infected with high-risk HPV, demonstrate lower sperm parameters and time-resistance activity during cryopreservation.

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.

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.

Intra Uterine Insemination in Two Couples with HPV Detection by Hyaluronidase-Based Swim-up Washing: Cases Report

Human papillomavirus (HPV) infection is the most common sexually transmitted disease worldwide and is associated with negative reproductive outcomes because of which it is recommended to postpone medically assisted reproduction (MAR). This raises major concerns for elder infertile couples. We showed that a hyaluronidase-based sperm washing (IALu) procedure blunted the HPV viral load in semen. Here, were report two cases of couples with long-term idiopathic infertility, ascribed to persistent semen HPV detection, finding a beneficial outcome from the use of IALu protocol applied to intra-uterine insemination (IUI). Case 1: A Caucasian couple (female aged 32, male aged 35), complained of having been attempting pregnancy for 4 years. HPV-DNA (genotypes 51 and 54) was detected on sperms. After a first unsuccessful IUI cycle attempt, using standard swim-up selection of spermatozoa, a second IUI cycle using the IALu procedure was associated with a pregnancy and a successful trimester of gestation. Case 2: A Caucasian couple (female aged 43, male aged 52) complained of having been attempting pregnancy for 3 years and showed the detection of HPV-DNA (genotype 66) on sperms. After a first unsuccessful standard IUI cycle attempt, two further IUI cycles using IALu procedure were pursued. The last cycle was associated with a pregnancy and a successful trimester of gestation. Although preliminary, the IALu procedure is a promising approach for straightforward fertility treatments in cases of recurrent HPV-DNA semen detection, avoiding critical latencies.

The negative impact of most relevant infections on fertility and assisted reproduction technology

Infections may act with variable impact on the physiopathology of the reproductive organs, determining infertility or reducing the outcomes of assisted reproduction technology. The aim of this narrative review is to describe the existing evidence regarding the pathogens with a supposed or recognized role in reproductive medicine. Viral hepatitis, as well as HIV, can reduce sperm quality. Syphilis carries a risk of erectile dysfunction and increased endometrial thickness. Chlamydia is the main cause of pelvic inflammatory disease. In relation to Mycoplasma and Ureaplasma spp., only few species seem to show a correlation with infertility and poor in-vitro fertilization outcomes. There is evidence of a role for bacterial vaginosis in early pregnancy loss. HPV infection in males seems to determine infertility. Herpesviruses are more a risk for fetuses than for fertility itself. Zika virus is responsible for altered early embryo development and waiting to conceive is recommended in suspected or confirmed cases. The impact of SARS-CoV-2 is yet to be elucidated. Rubella and toxoplasmosis can provoke important congenital defects and therefore screening is mandatory before conception; a vaccine for Rubella is recommended. Further and well-designed studies are still needed to better elucidate the role of some infectious agents, to improve fertility and its treatments.

The evaluation of Human papilloma virus and human herpes viruses (EBV, CMV, VZV HSV-1 and HSV-2) in semen samples

There are a number of risk factors, especially viral diseases, which can lead to infertility. Among the various viral infections, much attention has been given to the role of the Papillomaviridae and Herpesviridae. After collecting 82 semen samples (37 teratospermia, 2 asthenozoospermia, 2 oligoasthenospermia, 1 oligospermia, 6 asthenoteratospermia and 34 normal semen samples), and washing them, the DNA from both freshly ejaculated spermatozoon and washed spermatozoa was extracted. Subsequently, the prevalence of EBV, CMV, HSV-1, HSV-2, VZV and HPV was evaluated using Multiplex PCR and Nested PCR. In this study, 1 normal and 5 abnormal semen samples were infected with HSV-1 (1 normal, 4 teratospermia and 1 oligoasthenospermia). In addition, there were 2 VZV-positive samples (both were teratozoospermia). Nested PCR indicated that 1 asthenozoospermia, 1 asthenoteratospermia, 3 teratospermia and 4 normal samples were HPV positive (including 8 HPV-18 and 1 HPV-33). Among 9 HPV-positive subjects, 3 samples were negative after washing the infected samples. The prevalence of EBV, CMV, VZV, HSV-1 and HSV-2 remained unchanged prior to and after washing. Maybe sperm washing can be useful to eliminate HPV infection from semen samples, but further investigation is required because of the small number of samples.

Association between human papillomavirus infection and sperm quality: A systematic review and a meta-analysis

Human papillomavirus (HPV) has a high incidence rate in both males and females. HPV infection in women has been shown to affect fertility and lead to foetal death and pregnancy loss. However, research on HPV infection in men is limited. The aim of this study was to study the effect of HPV infection in semen on sperm quality and present the findings of previous studies through a meta-analysis. Databases including PubMed, MEDLINE, EMBASE, Web of Science, Cochrane Library, WanFang data and China National Knowledge Infrastructure were searched for relevant studies. A systematic review and meta-analysis were performed, and 17 studies were included for analyses based on a set criterion. Meta-analyses indicated that HPV infection in semen significantly reduced sperm concentration (SMD = -0.12, 95% CI: -0.21 to -0.03, p = .009), sperm motility (SMD = -0.55, 95% CI: -0.780 to -0.33, p = .000), sperm viability (SMD = -0.55, 95% CI: -0.780 to -0.33, p = .000) and sperm morphology (SMD = -0.34, 95% CI: -0.61 to -0.07, p = .015). The high-risk HPV (HrHPV) infection could significantly reduce sperm count (SMD = -0.65, 95% CI: -1.11 to -0.18, p = .007) compared with high-risk HPV (LrHPV) infection. In conclusion, HPV infection in semen significantly reduced sperm quality, and the HrHPV infection could significantly reduce sperm count compared with LrHPV.

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.

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.

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.

Investigation on Spontaneous Abortion and Human Papillomavirus Infection

Viral infections are considered to be risk factors for spontaneous abortion (SA). Conflicting results have been reported on the association between Human Papillomavirus (HPV) and SA. HPV DNA was investigated in matched chorionic villi tissues and peripheral blood mononuclear cells (PBMCs) from women who experienced SA (n = 80, cases) and women who underwent a voluntary interruption of pregnancy (VI; n = 80, controls) by qualitative PCR and quantitative droplet digital PCR (ddPCR). Viral genotyping was performed using real-time PCR in HPV-positive samples. Specific IgG antibodies against HPV16 were investigated in sera from SA (n = 80) and VI (n = 80) females using indirect ELISA assays. None of the DNA samples from SA subjects was HPV-positive (0/80), whilst HPV DNA was detected in 2.5% of VI women (p > 0.05), with a mean viral DNA load of 7.12 copy/cell. VI samples (n = 2) were found to be positive for the HPV45 genotype. The ddPCR assay revealed a higher number of HPV-positive samples. HPV DNA was detected in 3.7% and 5% of SA and VI chorionic tissues, respectively, with mean viral DNA loads of 0.13 copy/cell in SA and 1.79 copy/cell in VI (p >0.05) samples. All DNA samples from the PBMCs of SA and VI females tested HPV-negative by both PCR and ddPCR. The overall prevalence of serum anti-HPV16 IgG antibodies was 37.5% in SA and 30% in VI (p > 0.05) women. For the first time, HPV DNA was detected and quantitatively analyzed using ddPCR in chorionic villi tissues and PBMCs from SA and VI women. Circulating IgG antibodies against HPV16 were detected in sera from SA and VI females. Our results suggest that HPV infection in chorionic villi may be a rare event. Accordingly, it is likely that HPV has no significant role in SA.

Impact of COVID-19 and other viruses on reproductive health

Male infertility is linked to some viral infections including human papillomavirus (HPV), herpes simplex viruses (HSV) and human immunodeficiency viruses (HIVs). Almost nothing is known about severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) effect on fertility. The possible risk factors of coronavirus disease 2019 (COVID‐19) infection on fertility comes from the abundance of angiotensin‐Converting Enzyme‐2 (ACE2), receptor entry of the virus, on testes, a reduction in important sex hormone ratios and COVID‐19‐associated fever. Recent studies have shown a gender difference for COVID‐19 rates and comorbidity. In this review, we will discuss the potential effect of COVID‐19 on male fertility and talk about what needs to be done by the scientific community to tackle our limited understanding of the disease. On the other side, we will focus on what is known so far about the risk of COVID‐19 on pregnancy, neonatal health and the vertical transfer of the virus between mothers and their neonates. Finally, because reproduction is a human right and infertility is considered a health disease, we will discuss how assisted reproductive clinics can cope with the pandemic and what guidelines they should follow to minimise the risk of viral transmission.

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.

The risk of human papillomavirus infection for male fertility abnormality: a meta-analysis

Human papillomavirus (HPV) is the most common sexually transmitted virus in males and females worldwide; yet its impact upon male fertility remains unclear. The objective of this study was to evaluate the potential impact of HPV infection in semen on male fertility abnormality. A systematic literature search was performed in PubMed, Medline, Embase, Web of Science, and the Cochrane Library database for relevant publications up to May 6, 2017. The odds ratio (OR), and its corresponding 95% confidence interval (CI), was selected to represent the effect size. Statistical analysis was conducted using STATA 12.0. In total, eight articles, providing data on 1955 participants, were included in this meta-analysis. Collectively, the data suggested that HPV infection of semen was a risk factor for male fertility abnormality with an OR of 3.02 (95% CI: 2.11-4.32; I² = 6.9%). Sensitivity analysis revealed that the results of this study were robust. In conclusion, HPV infection of semen represents a risk factor for male fertility abnormality.

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).

[Sexually transmitted infections and male fertility]

BACKGROUND

Sexually transmitted infections (STI) are common worldwide and can cause impairment of fertility. In women pelvic inflammatory disease with subsequent tubal sterility is well-documented but the influence of STI on male fertility is still controversely discussed OBJECTIVE: The effects of various bacterial and viral STI on male fertility are discussed.

MATERIAL AND METHODS

An evaluation of the international literature up to 30 April 2018 was carried out including studies on larger collectives from the Asiatic region.

RESULTS

There is still an inconsistent picture of the influence of various bacterial and viral STI on male fertility. Direct or indirect evidence of the impact of a pathogen alone on the quality of ejaculates could not be clearly demonstrated; however, there are indications of a negative effect by Mycoplasma and Ureaplasma species in large Asiatic collectives. The transmission of viral pathogens, such as human papillomavirus (HPV), herpes simplex virus (HSV) and hepatitis B virus (HBV) possible impairs the success of assisted reproductive techniques. In contrast, manifest inflammatory processes of the male genital tract caused by STI (in particular Chlamydia and gonococci) or human immunodeficiency virus (HIV) infections often result in impairment of sperm qualtity.

CONCLUSION

In cases of male fertility disorders a microbiological clarification is recommended. Further studies on the effect of STI on male fertility in larger collectives are necessary, particularly for Caucasian populations. The utilization of existing preventive measures, such as screening for Chlamydia in young women and HPV vaccination also for young males, should be intensively promoted.

Role of Viral Infections in Testicular Cancer Etiology: Evidence From a Systematic Review and Meta-Analysis

The most represented histotype of testicular cancer is the testicular germ-cell tumor (TGCT), both seminoma and non-seminoma. The pathogenesis of this cancer is poorly known. A possible causal relationship between viral infections and TGCTs was firstly evoked almost 40 years ago and is still a subject of debate. In the recent past, different authors have argued about a possible role of specific viruses in the development of TGCTs including human papillomavirus (HPV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), Parvovirus B-19, and human immunodeficiency virus (HIV). The aim of this present review was to summarize, for each virus considered, the available evidence on the impact of viral infections on the risk of developing TGCTs. The review was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We included all observational studies reported in English evaluating the correlations between viral infections (HPV, CMV, EBV, Parvovirus B19, and HIV) and TGCTs. The methodological quality of studies included in the meta-analysis was evaluated using a modified version of the "Newcastle-Ottawa Scale." Meta-analyses were conducted using the "Generic inverse variance" method, where a pooled odds ratio (OR) was determined from the natural logarithm (LN) of the studies' individual OR [LN (OR)] and the 95% CI. A total of 20 studies (on 265,057 patients) were included in the review. Meta-analysis showed an association with TGCTs only for some of the explored viruses. In particular, no association was found for HPV, CMV, and Parvovirus B-19 infection (p = ns). Conversely, EBV and HIV infections were significantly associated with higher risk of developing TGCTs (OR 7.38, 95% CI 1.89-28.75, p = 0.004; OR 1.71, 95% CI 1.51-1.93, p < 0.00001). In conclusion, we found adequate evidence supporting an oncogenic effect of HIV and EBV on the human testis. Conversely, available data on HPV and TGCTs risk are conflicting and further studies are needed to draw firm conclusions. Finally, current evidence does not support an effect of CMV and Parvovirus B-19 on testicular carcinogenesis.

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.

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.

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.

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.

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.

Awareness and knowledge of human papillomavirus-related diseases are still dramatically insufficient in the era of high-coverage vaccination programs

PURPOSE

Assess knowledge and awareness concerning human papillomavirus (HPV) infection, HPV-associated diseases, and the existence of a specific vaccine among non-HPV-screened Caucasian-European adults after the market introduction of HPV vaccines.

METHODS

A cohort of 934 consecutive patients seeking their first medical help for uroandrologic purposes anonymously completed a 17-item questionnaire related to HPV. Data were compared with those of an age-comparable cohort of nurses (controls; n = 172).

RESULTS

Knowledge and awareness of HPV infection were reported in 564 (51%) and 735 (66.5%) participants, respectively. Overall, 51.3% participants were informed that HPV is sexually transmitted, but most reported not being aware that HPV infection can be associated with anogenital warts (61.7%), female genitalia (46.6%), penile (58.5%), and oropharyngeal cancer (79.7%). Only 36.5% of the participants were informed regarding the existence of a specific vaccine. HPV knowledge was retrieved through the media and/or the Internet, at school, doctors, and relatives or friends in 395 (35.7%), 155 (14%), 97 (8.8%), and 88 (8.0%) participants, respectively. Multivariable analyses showed that female gender [odds ratio (OR) 3.08; p < 0.001; 95% confidence interval 2.18-4.35] and educational status [high school diploma versus primary-secondary (OR 1.61; p = 0.03; 1.04-2.51); university degree versus primary-secondary (OR 2.89; p < 0.001; 1.83-4.57)] were significantly associated with awareness of HPV.

CONCLUSIONS

Only approximately half of the participants reported knowing what HPV infection is, even after the approval and market introduction of the HPV vaccine. Awareness about the existence and availability of a HPV vaccine was even lower.

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.

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

Recent evidences identify Human Papillomavirus (HPV) sperm infection as a possible cause of male and couple infertility. It acts through different mechanisms at various steps of human conception and early gestational development. We performed a systematic review to assess the role of HPV semen infection on male and couple infertility. Analysis of available and eligible data does not permit us to fund clear evidences about clinical impact of HPV infection on fertility, although sperm parameters impairment is the most widely recognized effect. Regarding biomolecular implications, the available data are often conflicting. More studies are required to define the role of HPV sperm infection in clinical practice. The great majority of evidences are obtained by in vitro studies and this fact represents a limitation for the clinical management of HPVDNA sperm infection. Understanding the biological significance of HPV-DNA semen infection could permit us to explain most of the idiopathic male and couple infertility, leading to a better management of infertile men and a better timing for sperm banking storage before ART cycles.

Prevalence of human papillomaviruses in semen: a systematic review and meta-analysis

STUDY QUESTION

What is the prevalence of human papillomavirus (HPV) in semen?

SUMMARY ANSWER

HPV is present in the semen of asymptomatic men, with a pooled prevalence in a random effects meta-analysis of populations seeking fertility evaluation/treatment of 16%, versus 10% in other populations.

WHAT IS KNOWN ALREADY

The main risk of donor insemination (DI) is known to be contamination with an infectious agent. HPV is the necessary cause of cervical cancer, and plays an etiologic role in other anogenital cancers. Although it is known to be prevalent and sexually transmitted, donor semen specimens are not tested for the presence of HPV.

STUDY DESIGN, SIZE, DURATION

A systematic review and meta-analysis of studies published between January 1980 and June 2013 were performed. Variables collected included characteristics of study populations, method of semen preparation, HPV DNA detection and genotyping, HPV types targeted and proportion of HPV positivity.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two investigators independently assessed the studies for inclusion in the review and abstracted the data, while others reviewed the extracted data in detail. Studies were included if they provided data on HPV DNA prevalence in semen and PCR-based methods were used. For the meta-analysis, reports were separated according to the study populations, creating two distinct subgroups: populations seeking fertility evaluation/treatments, and other populations. Data were analysed using a random effects model for each subpopulation.

MAIN RESULTS AND THE ROLE OF CHANCE

The literature search identified 285 studies, and in the 27 studies that were included the HPV DNA prevalence in 4029 semen samples varied from 0 to 100%. The three studies focusing on sperm donors identified HPV DNA in 26.3, 7.5 and 16.0% of semen samples. HPV-16 was the most common type overall. The pooled prevalence in a random effects meta-analysis of seven studies focusing on infertile populations was 16% [95% confidence interval (CI): 10-23%] versus 10% (95% CI: 7-14%) in 11 reports focusing on other populations.

LIMITATIONS, REASONS FOR CAUTION

First, despite defining clinically relevant subgroups, substantial heterogeneity remained. Secondly, although we retrieved data from reports in English or French only, after reviewing the five reports in other languages only two more could have been added and, as their prevalence estimates were similar to those of studies included in our review, we do not believe that exclusion of these reports biased our results or conclusions.

WIDER IMPLICATIONS OF THE FINDINGS

HPV DNA can be found in donor semen and preliminary studies confirm genome activity. For this reason, and although the exact consequences of insemination with HPV-infected semen (cervical infections/lesions, impact on success rate of DI) remain to be clarified, we believe that HPV-infected sperm should be considered a health risk unless well-designed studies prove otherwise. The development and validation of adequate sperm washing techniques before DI appears to be a promising option.

STUDY FUNDING/COMPETING INTEREST(S)

C.L. and P.M. have no conflicts of interests relevant to the submitted work. H.T. has served as a consultant and on advisory boards and has received speaker fees and travel assistance from Merck-Frosst Canada, Glaxo SmithKline Pharmaceuticals, Belgium and Gilead Sciences. F.C. has received grants through his institution from Merck and Roche, as well as honoraria from Merck and Roche for lectures on HPV. M.-H.M. has received grants though her institution from Merck and Qiagen and lecture honoraria from Merck and GSK for conferences on HPV and best practices in cervical cancer prevention.

TRIAL REGISTRATION NUMBER

N/A.

Detection of human herpesviruses (HHVs) in semen of human male infertile patients

Recently we demonstrated an ectopic expression of the human herpesvirus 1 thymidine kinase (HHV1-TK) gene by functioning of an intrinsic endogenous promoter in the transgenic rat (TG-rat), suggesting that HHV1 infection in humans induces expression of the TK gene with the ectopic promoter in the testis and results in accumulation of HHV1-TK protein, triggering male infertility similar to that in the TG-rat. Hence, in this study, we started to investigate a relationship between infection of herpesvirus and human male infertility. Semen was donated by Chinese male infertile patients (153 men, aged 21-49 years) with informed consent, followed by DNA preparation and analysis by PCR and DNA sequencing. Semen volume, sperm number and density, and sperm motility were examined. DNAs of HHV1, HHV4, HHV5 and HHV6 were confirmed by PCR, electrophoresis and DNA sequencing. Finally, virus DNA was identified in 59 patients (39%). The number of carriers was 39 (25%) for HHV1, 6 (4%) for HHV4, 33 (22%) for HHV5 and 3 (2%) for HHV6, respectively. Moreover, double-infection was found in 22 out of 59 specimens (37%), most of which were double-infection of HHV1 and HHV5 (15 out of 22 carriers). Though slight severity was present in some of the carriers, the relationship between virus infection and sperm impairment was not conclusive. Accordingly, it is essential to examine whether the viral HHV1-TK gene is expressed in the testis of the infertile human HHV carrier.

Testicular cancer and HPV semen infection

Testicular cancer represents the more frequent solid tumor affecting males aged 15-35 years. In the last decades, its incidence showed a progressive increased probably due to genetic and environmental factors. Despite exposure to some viruses such as HIV, HCV, EBV, and HPV is frequently related to cancer development, there are no studies aimed to evaluate the possible implication of viral infections in the pathogenesis of testicular cancer. In this study, we analyzed sperm parameters and prevalence of HPV on sperm in 155 testicular cancer patients at diagnosis (T-1), after orchiectomy (T0) and after 12 months from surgery or from the end of adjuvant treatments (T12). All patients showed a significantly higher prevalence of semen infection than controls (9.5% and 2.4% respectively,) and altered sperm parameters both at T-1 and T0. Considering sperm parameters, at T-1 we observed a reduction of progressive motility, and after orchiectomy patients showed a reduction of sperm concentration and count and a further worsening of motility. Thereafter, patients were assigned to three groups on the basis of medical option after surgery: S = surveillance, R = radiotherapy, and C = chemotherapy +/- radiotherapy. At T12, untreated patients had an improvement of sperm parameters while R group and even more C group had a strong decrease of sperm number (p < 0.01 both vs. T0 and S group). Moreover, patients who received radio and/or chemotherapy had a very high prevalence of HPV semen infection (S = 7.7%, R = 30.8%, and C = 61.5%). In conclusion, patients with testicular cancer had frequently altered sperm parameters and higher prevalence of HPV semen infection that were worsened after radio and chemotherapy. Because HPV infection is a risk factor for cancer development and it may further reduce fertility, we suggest screening for HPV in testicular cancer patients at diagnosis and particularly after adjuvant treatments.