The Impact of Human Papilloma Virus on Human Reproductive Health and the Effect on Male Infertility: An updated Review

Efficacy of human papillomavirus vaccines in the prevention of male genital diseases: a systematic review

OBJECTIVES

To evaluate the results of randomised controlled trials (RCTs) regarding the efficacy of human papillomavirus (HPV) vaccination in preventing male genital-related diseases.

METHODS

A systematic search of English language literature using PubMed, Scopus, and Cochrane Library was performed in April 2024 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol.

RESULTS

Evidence from four RCTs (including 7008 male participants) support the efficacy of the quadrivalent HPV vaccine in preventing genital warts and persistent HPV infection in HPV-naïve men. The low incidence of male genital malignancies in the control groups of the reported studies lead to underpowered evidence. However, vaccination leads to durable protection with a long-term follow-up of 10 years showing efficacy of 91.8% to prevent HPV 6-, 11-, 16-, or 18-related external genital lesions (EGLs) in HPV-naïve subjects. Additionally, the quadrivalent vaccine seems to effectively reduce the detection of DNA from all four HPV types.

CONCLUSION

In summary, early quadrivalent HPV vaccination demonstrates efficacy in preventing HPV infection and EGLs in males. Well controlled prospective studies are needed to confirm the long-term efficacy, specifically in cancer prevention, in all men and specific subject subgroups, and to identify the targeted population who is most likely to benefit from early vaccination.

Effect of human papillomavirus infection on semen quality and assisted reproductive technology outcomes: a prospective observational cohort study

BACKGROUND

Human papillomavirus (HPV) adversely affects human reproduction. We aimed to evaluate the prevalence of HPV infection in men and its correlation with semen parameters and reproductive outcomes.

METHODS

In this prospective observational cohort study, 384 semen samples were collected from 237 male partners of infertile couples. The presence of HPV DNA and genotyping were analyzed in semen by quantitative PCR. A total of 186 intrauterine inseminations (IUI) in 101 couples and 186 assisted reproduction techniques (ART) cycles in 155 couples were performed. Associations between HPV positivity and semen parameters and fertility outcomes were evaluated using a generalized linear mixed model.

RESULTS

The prevalence of HPV was 22.7%. Twenty-three HPV types were detected and 69.5% of positive samples presented at least one high risk (HR)-HPV genotype. HPV-18 (14%), HPV-53 (10%), and HPV-56 (10%) were the most prevalent HR-HPV genotypes followed by HPV-16, HPV-31, and HPV-51 (8%). HPV-42 was the most prevalent low risk (LR)-HPV genotype (25%). More than one HPV type was detected in 41% of HPV + samples. After capacitation, 30% of HPV + samples remained positive. We found no relationship between HPV infection and sperm volume, sperm concentration, and progressive motility both before and after semen capacitation. We observed a not significant different clinical pregnancy per cycle in the HPV - (6.8%) and HPV + (5.0%) IUI. We did not find any significant difference in fertilization, cleavage, quality of developed embryos, blastocyst formation nor in embryo utilization of ART cycles. Slightly lower cumulative pregnancy (33% vs 39%) and live-birth (25% vs 30%) rates and higher miscarriage rate (53% and 29%) were observed in HPV + with respect to HPV - cycles. Fifty-five neonatal outcomes from HPV - (n = 45) and HPV + (n = 10) cycles were available. No stillbirths as well as no malformations were recorded.

CONCLUSIONS

This study confirmed previous findings that HPV DNA is present in semen of one quarter of infertile couples. No significant association of seminal HPV presence with semen parameters was found. We observed a trend of worst clinical outcomes in the HPV + group that is worth further investigation in a large population to draw definitive conclusions.

Human Papillomavirus Infection in Partners of Women Attending Cervical Cancer Screening: A Pilot Study on Prevalence, Distribution, and Potential Use of Vaccines

Background/Objectives: Human Papillomavirus (HPV) cross-infection among couple's partners is a widespread event and could lead to persistent infections. Unfortunately, the influence of male sexual partners of HPV-positive women on their cervical lesions and the potential role of HPV vaccines have been under-investigated. We evaluated the HPV prevalence in male partners of HPV-infected women, focusing on the possible correlation between partners' cervical lesions and the role of HPV vaccination. Methods: Two samples, genital and urethral swabs, were collected for each of the 90 patients recruited. HPV-DNA detection was carried out by the Allplex HPV28 detection assay. Results: HPV prevalence was 66.7% (60/90); high-risk HPV (hrHPV) genotypes were detected in 90% (54/60) cases and multiple infections in 55% (33/60). The most frequent hrHPVs were HPV31 (p = 0.0265) and HPV52 (p = 0.002), found in 18.3% (11/60) of cases, and HPV53 (p = 0.0116) in 16.7% (10/60). Statistical analysis showed a higher probability of a less severe cytological diagnosis with the increase in the number of genotypes detected (p = 0.0146). Among the HPV-positive partners of females with cervical lesions, 18.7% (6/32) and 62.5% (20/32) had vaccine genotypes of the quadrivalent and nonavalent vaccines, respectively. The nonavalent vaccine showed a significantly higher potential to prevent lesions (62.5% vs. 18.7%, p = 0.0001), with an absolute additional potential impact (AAI) of 31.1% in histological and 32.4% in cytological diagnoses. Conclusions: These preliminary results provide new insight into the correlation between the number of partner genotypes and the severity of cervical lesions and show promising results for the preventive potential of vaccinating male partners.

Impact of Human Papillomavirus (HPV) on Male and Female Fertility

Human papillomaviruses (HPVs) are responsible for the majority of sexually transmitted infections (STIs), some of which are oncogenic and can cause oropharyngeal or genital cancers. The HPV prevalence at the genital level varies according to the population studied but is higher in the seminal fluid of men suffering from idiopathic infertility than in the general population. The involvement of HPV in male infertility is supported by several studies suggesting that this virus can affect sperm quality by altering sperm DNA integrity, motility, number, viability, and morphology, and by inducing the production of anti-sperm antibodies (ASAs). HPVs may also have an impact on female fertility, mainly by increasing the risk of miscarriage and premature delivery and by altering the implantation of endometrial trophoblastic cells. In addition, an association with vaginal bacterial dysbiosis, notably involving Gardnerella vaginalis, or co-infection with an STI agent, serves as an aggravating factor. The aim of this review is to present current data on the potential role of HPVs in male and female infertility, along with data on infertility prevention and treatment strategies and the impact of vaccination in this context.

Impact of high-risk and low-risk human papillomavirus infections on the male genital tract: effects on semen inflammation and sperm quality

Human Papillomavirus (HPV), a prevalent sexually transmitted infection, comprises high-risk (HR-HPV) and low-risk (LR-HPV) viruses, the former posing a high risk for developing malignancies whereas the latter mainly for benign warts. Despite increasing awareness of HPV's impact on men's health, the influence of HR-HPV and LR-HPV urogenital infections on male fertility potential remains uncertain. This study aimed to investigate whether male urogenital infection with HR- or LR-HPV associates with impaired sperm quality, oxidative stress, and inflammation. A total of 205 male patients attending an urology clinic were enrolled. Semen samples were analyzed for HPV using PCR and genotyped by RFLP. Semen quality was evaluated following WHO guidelines. Semen leukocytes, reactive oxygen species (ROS), and sperm viability were analyzed using flow cytometry. HPV was detected in 19% (39/205) of semen samples. HR-HPV infections were more prevalent, with HPV-16 being the most frequent genotype. Neither HR-HPV nor LR-HPV were associated with significant alterations in routine sperm quality parameters. However, HR-HPV+ individuals showed significantly higher levels of sperm necrosis and exhibited increased proportions of ROS+ spermatozoa compared to LR-HPV+ or control individuals. Furthermore, no significant semen inflammation was detected in patients infected with either HR-HPV or LR-HPV, and unexpectedly reduced semen leukocytes and inflammatory cytokines (IL-6 and IL-1β) were observed in HR-HPV+ patients compared to controls. These observations underscore the importance of comprehensive HPV screening, including genotyping, in urology and fertility clinics to understand the progression of the infection, potential adverse effects on reproductive health, and the oncogenic risks involved.

Automatic high-throughput and non-invasive selection of sperm at the biochemical level

BACKGROUND

Sperm selection, a key step in assisted reproductive technology (ART), has long been restrained at the preliminary physical level (morphology or motility); however, subsequent fertilization and embryogenesis are complicated biochemical processes. Such an enormous "gap" poses tough problems for couples dealing with infertility, especially patients with severe/total asthenozoospermia .

METHODS

We developed a biochemical-level, automatic-screening/separation, smart droplet-TO-hydrogel chip (BLASTO-chip) for sperm selection. The droplet can sense the pH change caused by sperm's respiration products and then transforms into a hydrogel to be selected out.

FINDINGS

The BLASTO-chip system can select biochemically active sperm with an accuracy of over 90%, and its selection efficiency can be flexibly tuned by nearly 10-fold. All the substances in the system were proven to be biosafe via evaluating mice fertilization and offspring health. Live sperm down to 1% could be enriched by over 76-fold to 76%. For clinical application to patients with severe/total asthenozoospermia, the BLASTO-chip could select live sperm from human semen samples containing 10% live but 100% immotile sperm. The rates of fertilization, cleavage, early embryos, and blastocysts were drastically elevated from 15% to 70.83%, 10% to 62.5%, 5% to 37.5%, and 0% to 16.67%, respectively.

CONCLUSIONS

The BLASTO-chip represents a real biochemical-level technology for sperm selection that is completely independent of sperm's motility. It can be a powerful tool in ART, especially for patients with severe/total asthenozoospermia.

FUNDING

This work was funded by the Ministry of Science and Technology of China, the Ministry of Education of China, and the Shenzhen-Hong Kong Hetao Cooperation Zone.

Identification of potential biomarkers and pathways for asthenozoospermia by bioinformatics analysis and experiments

Background

Asthenozoospermia, a type of male infertility, is primarily caused by dysfunctional sperm mitochondria. Despite previous bioinformatics analysis identifying potential key lncRNAs, miRNAs, hub genes, and pathways associated with asthenospermia, there is still a need to explore additional molecular mechanisms and potential biomarkers for this condition.

Methods

We integrated data from Gene Expression Omnibus (GEO) (GSE22331, GSE34514, and GSE160749) and performed bioinformatics analysis to identify differentially expressed genes (DEGs) between normozoospermia and asthenozoospermia. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted to gain insights into biological processes and signaling pathways. Weighted Gene Co-expression Network Analysis (WGCNA) identified gene modules associated with asthenozoospermia. Expression levels of key genes were assessed using datasets and experimental data. Gene Set Enrichment Analysis (GSEA) and correlation analysis identified pathways associated with the hub gene and explore the relationship between the ZNF764 and COQ9 and mitochondrial autophagy-related genes. Competitive endogenous RNA (ceRNA) networks were constructed, and in vitro experiments using exosome samples were conducted to validate this finding.

Results

COQ9 was identified as a marker gene in asthenozoospermia, involved in autophagy, ATP-dependent chromatin remodeling, endocytosis, and cell cycle, etc. The ceRNA regulatory network (LINC00893/miR-125a-5p/COQ9) was constructed, and PCR demonstrated that LINC00893 and COQ9 were downregulated in asthenozoospermia, while miR-125a-5p and m6A methylation level of LINC00893 were upregulated in asthenozoospermia compared to normozoospermic individuals.

Conclusion

The ceRNA regulatory network (LINC00893/miR-125a-5p/COQ9) likely plays a crucial role in the mechanism of asthenozoospermia. However, further functional experiments are needed to fully understand its significance.

Determinants of Parental Intention to Vaccinate Young Adolescent Girls against the Human Papillomavirus in Taiwan: An Online Survey Study

Since 2018, Taiwan has included the human papillomavirus (HPV) vaccination into its national immunization program for junior high school girls. However, the reports of side effects following vaccination have increased parental concerns. This study investigated parental intentions regarding the HPV vaccination for their daughters and related factors in Taiwan. A total of 213 parents of girls aged between 12 and 15 years participated in an online survey. The survey collected data on various factors, including the parental intention to vaccinate their daughters against HPV; the motivation behind the vaccinations, as measured using the Motors of Human Papillomavirus Vaccination Acceptance Scale; an understanding of the reasons behind the government's promotion of HPV vaccinations; concerns regarding the side effects of vaccinations for their daughters; an awareness of the reported side effects of HPV vaccines experienced by some individuals; the exposure to information on HPV vaccines from social media; and mental health status, measured using the Brief Symptom Rating Scale. The associations between these variables and the parental intention to vaccinate their daughters against HPV were examined using a multivariable linear regression analysis model. The findings revealed a moderate to high level of intention among participants to vaccinate their daughters against HPV. Parents who perceived a greater value in HPV vaccination for their daughters' health (B = 0.524, standard error [se] = 0.039, p < 0.001) and had greater autonomy in decision-making regarding vaccination (B = 0.086, se = 0.038, p = 0.026) exhibited a higher intention to vaccinate their daughters against HPV. Conversely, parents who expressed greater concern regarding the side effects of HPV vaccines for their daughters had a lower intention to vaccinate (B = -0.762, se = 0.203, p < 0.001). Based on these findings, this study recommends integrating these factors into the design of intervention programs aimed at enhancing parental intentions to vaccinate their daughters against HPV.

Update on known and emergent viruses affecting human male genital tract and fertility

Many viruses infect the male genital tract with harmful consequences at individual and population levels. In fact, viral infections may induce damage to different organs of the male genital tract (MGT), therefore compromising male fertility. The oxidative stress, induced during viral-mediated local and systemic inflammation, is responsible for testicular damage, compromising germinal and endocrine cell functions. A reduction in sperm count, motility, number of normal sperm and an increase in DNA fragmentation are all common findings in the course of viral infections that, however, generally regress after infection clearance. In some cases, however, viral shedding persists for a long time leading to unexpected sexual transmission, even after the disappearance of the viral load from the blood.The recent outbreak of Zika and Ebola Virus evidenced how the MGT could represent a reservoir of dangerous emergent viruses and how new modalities of surveillance of survivors are strongly needed to limit viral transmission among the general population.Here we reviewed the evidence concerning the presence of relevant viruses, including emergent and re-emergent, on the male genital tract, their route of entry, their adverse effects on male fertility and the pattern of viral shedding in the semen.We also described laboratory strategies to reduce the risk of horizontal or vertical cross-infection in serodiscordant couples undergoing assisted reproductive technologies.

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.

Evaluation of Human Papillomavirus in the Semen of Infertile Men and Its Relationship with Semen Quality

Background: The prevalence of human papillomavirus (HPV) infection in infertile men is significantly higher than that in the general population. Nevertheless, it is unclear whether the presence of HPV in semen samples is related to reduced semen quality. Objectives: The present article aims to elucidate the possible association between HPV infection and semen parameters in Iranian infertile men. Methods: This cross-sectional study included semen samples from 140 infertile Iranian male partners of couples seeking fertility assessment. Standard semen analysis was performed. Sperm DNA fragmentation index (DFI), sperm chromatin maturation, anti-sperm antibodies, leukocyte count, fructose concentration, and zinc concentration were also assessed. Nested polymerase chain reaction (PCR) and INNO-LiPA were used to identify HPV DNA sequences in semen samples and to determine HPV genotype, respectively. Independent samples t-tests were used to compare sperm parameters between HPV-positive and HPV-negative groups. Results: Human papillomavirus DNA was detected in 18 (12.85%) out of 140 semen samples (10% high-risk genotypes, 2.14% low-risk genotypes, and one sample was excluded). Our findings revealed that HPV18 was the most prevalent type (8.57%). According to our results, the presence of HPV DNA in semen samples was associated with higher semen anti-sperm antibodies (P = 0.001), higher white blood cell (WBC) counts (P = 0.02), and increased DFI values (P = 0.03). Conclusions: Human papillomavirus -positive patients had higher semen anti-sperm antibodies, semen WBC counts, and sperm DFI values. These results highlight the importance of careful screening for the presence of HPV in semen samples from infertile men. It should also be noted that more studies are required.