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

Transmission electron microscopy reveals the presence of SARS-CoV-2 in human spermatozoa associated with an ETosis-like response

BACKGROUND

Severe acute syndrome coronavirus 2 can invade a variety of tissues, including the testis. Even though this virus is scarcely found in human semen polymerase chain reaction tests, autopsy studies confirm the viral presence in all testicular cell types, including spermatozoa and spermatids.

OBJECTIVE

To investigate whether the severe acute syndrome coronavirus 2 is present inside the spermatozoa of negative polymerase chain reaction-infected men up to 3 months after hospital discharge.

MATERIALS AND METHODS

This cross-sectional study included 13 confirmed moderate-to-severe COVID-19 patients enrolled 30-90 days after the diagnosis. Semen samples were obtained and examined with real-time polymerase chain reaction for RNA detection and by transmission electron microscopy.

RESULTS

In moderate-to-severe clinical scenarios, we identified the severe acute syndrome coronavirus 2 inside spermatozoa in nine of 13 patients up to 90 days after discharge from the hospital. Moreover, some DNA-based extracellular traps were reported in all studied specimens.

DISCUSSION AND CONCLUSION

Although severe acute syndrome coronavirus 2 was not present in the infected men's semen, it was intracellularly present in the spermatozoa till 3 months after hospital discharge. The Electron microscopy (EM) findings also suggest that spermatozoa produce nuclear DNA-based extracellular traps, probably in a cell-free DNA-dependent manner, similar to those previously described in the systemic inflammatory response to COVID-19. In moderate-to-severe cases, the blood-testes barrier grants little defence against different pathogenic viruses, including the severe acute syndrome coronavirus 2. The virus could also use the epididymis as a post-testicular route to bind and fuse to the mature spermatozoon and possibly accomplish the reverse transcription of the single-stranded viral RNA into proviral DNA. These mechanisms can elicit extracellular cell-free DNA formation. The potential implications of our findings for assisted conception must be addressed, and the evolutionary history of DNA-based extracellular traps as preserved ammunition in animals' innate defence might improve our understanding of the severe acute syndrome coronavirus 2 pathophysiology in the testis and spermatozoa.

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.

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.

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

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

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

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

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.

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.

Prevalence of CBAVD in azoospermic men carrying pathogenic CFTR mutations - Evaluated in a cohort of 639 non-vasectomized azoospermic men

BACKGROUND

Men with obstructive azoospermia (OA) due to impaired development of the genital tract often carry at least one Cystic Fibrosis Transmembrane Conductance Regulator CFTR mutation.

OBJECTIVE

To determine the frequency of Congenital Bilateral Absence of Vas deferens (CBAVD) in men with azoospermia carrying CFTR gene mutations.

MATERIALS AND METHODS

Non-vasectomized men with azoospermia referred to our andrological center were consecutively included. All men underwent palpation of the scrotal parts of the Vasa deferentia, ultrasonography of the testicles and hormone profile, and genetic analyses. Testicular biopsy was usually performed. A panel of 32 of the most important CFTR mutations was examined from genomic DNA isolated from blood lymphocytes. Either multiplex PCR analysis or a next-generation sequencing technique was performed.

RESULTS

Among the 639 men with azoospermia, 69 (10.8%) had at least one CFTR mutation. Of the 43 patients with at least one of the two CFTR mutations, ΔF508 and R117H, 19 (44.2%) showed CBAVD, 2 (4.7%) Congenital Unilateral Absence of Vas deferens (CUAVD), and 22 (51.2%) presence of the scrotal parts of the Vasa deferentia. In contrast, only 1/21 men (4.8%) with an isolated IVS8-5T variant showed CBAVD. Among the further 20 men with an isolated IVS8-5T variant, 11 had a history of cryptorchidism. Among the 570 men without CFTR mutations, CBAVD was found in only two men and CUAVD in one. FSH level was higher and testicular volume lower in men with present Vasa deferentia compared to those without (P < .001; Student's t test). Thirty-one men with either ΔF508 or R117H mutations, or both, had a testicular biopsy. Motile spermatozoa were found in 100% of 16 cases with CBAVD but in only 6 out of 15 cases with present Vasa deferentia (P < .01; Fisher's exact test).

DISCUSSION AND CONCLUSIONS

CBAVD was found in ~ 44% of men with ΔF508/R117H mutations. The data may support that CFTR mutations might affect male fertility through other mechanisms than obstruction of the genital tract. For a practical, clinical purpose analysis for only ΔF508, R117H and IVS8-5T seems sufficient until further research shows anything else.

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.