Clustering patterns of human papillomavirus genotypes in multiple infections

The role of multiple high-risk human papillomavirus infection on the persistence recurrence of high-grade cervical lesions after standard treatment: A systematic review and a meta-analysis

INTRODUCTION

The role of multiple high-risk human papillomavirus (HR-HPV) infections on the occurrence of persistence/recurrence of high-grade squamous intraepithelial lesion (HSIL) after conization/surgery for cervical intraepithelial neoplasia was evaluated.

MATERIAL AND METHODS

A systematic search of Pubmed/Medine, Scopus, Cochrane databases from inception to June 30, 2023 was performed. Three reviewers independently screened the abstracts of the selected studies and extracted data from full-text articles. The data were subsequently tabulated and compared for consistency. The bias associated with each included study was evaluated according to the OSQE method. PROSPERO registration number CRD42023433022.

RESULTS

Out of 1606 records screened, 22 full text articles met the inclusion criteria. A total of 8321 subjects treated (loop electrosurgical excision, laser or surgery) because of HSIL were followed-up and included in the meta-analysis. The pooled prevalence of overall persistence and/or recurrence was 17.6 (95% CI: 12.3-23.5) in multiple and 14.3 (95% CI: 10.1-19.2) in single HR-HPV infections detected shortly before or at surgery. The pooled rate of multiple HR-HPV infections was 25% (95% CI: 20.4-30). The odds ratio of histologically confirmed HSIL persistence and/or recurrence was significantly higher (OR: 1.38, 95% CI:1.08-1.75, p = 0.01, heterogeneity = 39%) among multiple than single HR-HPV infections. Increased risk of HSIL persistence/recurrence was more marked among studies with multiple HR-HPVs prevalence ≥25% (12 studies, N = 3476) (OR: 1.47, 95% CI: 1.18-1.84, heterogeneity = 0%) and in those evaluating true histologically confirmed recurrence after at least 6 months of negative follow-up (9 studies, N = 5073) (OR: 1.67, 95% CI: 1.17-2.37, heterogeneity = 37%). Multiple HR-HPVs infection detected during follow-up visits had no effect on the risk of recurrence although the number of included studies was small (4 studies, N = 1248) (OR: 0.98, 95% CI: 0.68-1.39, heterogeneity = 0%). The risk of bias was rated as high in 10 and low-moderate in 12 studies, respectively. In subgroup analysis, the risk of bias of the included studies (low/moderate vs. high), had a small, although not significant effect on the odds ratios of persistence/recurrence of HSIL (OR: 1.57, 95% CI: 1.23-2 for low-moderate risk of bias and OR: 1.06, 95% CI: 0.65-1.75 for high risk of bias; p-value for subgroup differences = 0.17).

CONCLUSIONS

Multiple HR-HPVs infections at the time of standard treatment of HSIL entail a small but significant increased risk of persistence/recurrence of HSIL and should be taken into account in the follow-up plan.

Relative distribution of HPV genotypes in histological cervical samples and associated grade lesion in a women population over the last 16 years in Burgundy, France

Human papillomavirus is a predominant sexually transmitted viral pathogen. Our objective was to analyze the relative distribution of genotypes over time and to determine the genotypes associated with adverse clinical lesions. The study was based on data from adult women with cytological abnormalities from whom histological samples were obtained from 2005 to 2021. HPV genotyping was performed using PCR and INNO-LiPA assay (Fujirebio). Among the 1,017 HPV-positive biopsies, 732 (72%) were infected with a single HPV genotype and 285 (28%) were infected with several HPV genotypes. Most of the infections involved the high-risk genotypes 16, 31, and 52. Throughout the study period, HPV 16 was the most encountered genotype (541, 53.2%), while HPV 18 was rather under-represented (46, 4.5%), especially in invasive cervical carcinoma. HVP52 (165, 16.2%) was detected mainly from 2008 to 2014, and its distribution reached 19.7% in 2011. Such epidemiological data underlines the possibility of an emergence of a high-risk genotype. The most detected low-risk HPV in combination with high-risk HPV was HPV 54 in 6.5% of samples. Monoinfection by HPV 16 led statistically more often to severe lesions than multi-infection involving HPV 16 (p < 0.001), while for HPV 52, 31 or 33, multi-infections were significantly associated with severe lesions (p < 0.001 for each of these three genotypes). HPV 16 was involved in 55.2% of high-grade lesions and in situ carcinoma and 76.3% of invasive carcinomas. In severe lesions, HPV 16 participation was predominant, whereas diverse genotypes were seen in low-grade lesions. Importantly, we observed that high-risk genotypes, for example HPV 52, can emerge for a few years then decrease even without vaccine pressure.

Cervical Screening in North Sardinia (Italy): Genotype Distribution and Prevalence of HPV among Women with ASC-US Cytology

The assessment of human papillomavirus (HPV) genotype dynamics could support the adoption of more tailored preventive actions against cervical cancer. The aim of the study was to describe the prevalence of HPV infection, HPV genotype distribution, and the epidemiological characteristics of women with ASC-US cytology since the introduction of HPV-DNA testing in Sardinia (Italy), (March 2016–December 2020). Specimens were tested by RT-PCR for 14 high-risk HPV genotypes. A total of 1186 patients were enrolled, with a median (IQR) age of 41 (38–48) years. Of these women, 48.1% were positive for at least one HPV genotype; 311 (26.2%) women were vaccinated with a median (IQR) age of 38 (30/47) years. The percentage of prevalence of HPV-16, -31, -66, -56, and -51 was 36.3%, 18.7%, 11.9%, 11.4% and 10.7%, respectively. The highest prevalence of infection was found in women aged <41 years, and single women. Moreover, women aged >41 years (OR: 0.51, 95% CI: 0.31–0.86; p-value: 0.01), having parity (OR: 0.57, 95% CI: 0.34–0.96, p-value: 0.04), and higher educational level (OR: 0.39, 95% CI: 0.18–0.87; p-value: 0.02) were associated with a lower CIN2+ risk. We did not find a significant difference in terms of prevalence of HPV-16 infection between vaccinated and non-vaccinated (18.3% vs. 17.1%; p-value < 0.001). Our results support the adoption of nonavalent HPV-vaccine to prevent the most prevalent infections caused by HPV-16 and -31 genotypes and underscore the need of surveillance to implement tailored vaccination programs and preventive strategies.

High frequency of HPV genotypes 59, 66, 52, 51, 39 and 56 in women from Western Mexico

BACKGROUND

Human papillomavirus infection is an important factor associated with cervical cancer (CC) development. The prevalence and genotype distribution vary greatly worldwide. Examining local epidemiological data constitutes an important step towards the development of vaccines to prevent CC. In this work, we studied the prevalence of HPV genotypes in women from Western Mexico with the COBAS 4800 and/or Linear Array Genotyping Test (LA).

METHODS

The samples analysed in this study represent a population from Western Mexico, which includes six different states. Our approach was first to test for HPV in cervical samples from women who attended their health clinic for routine gynaecological studies (open-population, n = 3000) by utilizing COBAS 4800. Afterwards, 300 of the HPV-positive samples were randomly selected to be genotyped with LA; finally, we genotyped samples from women with cervical intraepithelial neoplasia grade 1 (CIN 1, n = 71) and CC (n = 96) with LA. Sociodemographic data of the diverse groups were also compared.

RESULTS

The overall HPV prevalence among the open-population of women as determined by COBAS 4800 was 12.1% (n = 364/3000). Among the HPV-positive samples, single infections (SI) with HPV16 were detected in 12.4% (n = 45/364), SI with HPV18 were detected in 1.4%, and infection with at least one of the genotypes included in the high-risk HPV pool was detected in 74.5% of the cases. LA analysis of the samples showed that in addition to HPV genotypes 16 and 18, there was a high prevalence of HPV genotypes 59, 66, 52, 51, 39 and 56 in women from Western Mexico. With respect to the sociodemographic data, we found statistically significant differences in the number of pregnancies, the use of hormonal contraceptives and tobacco intake.

CONCLUSIONS

Our data indicate that there is a high prevalence of HPV genotypes which are not covered by the vaccines currently available in Mexico; therefore, it is necessary to include HPVs 59, 66, 51, 39 and 56 in the design of future vaccines to reduce the risk of CC development. It is also essential to emphasize that the use of hormonal contraceptives and tobacco smoking are risk factors for CC development in addition to the presence of HPV.

Clinical Significance of the Interaction between Human Papillomavirus (HPV) Type 16 and Other High-Risk Human Papillomaviruses in Women with Cervical Intraepithelial Neoplasia (CIN) and Invasive Cervical Cancer

The aim is to evaluate the clinical consequences of coinfection between HPV 16 and other high-risk HPVs among women with a histological diagnosis of CIN or invasive cervical cancer. A total of 2985 women, with a diagnosis of either CIN or cancer (<IB) on cervical or cone biopsy, were included. HPV genotypes were identified using the INNO-LiPA HPV genotyping assay, version EXTRA, on cervical scraping, before the colposcopic evaluation and the colposcopic biopsies or conization. In the overall population, HPV16 interacted positively with HPV18 (RR = 2, 95% CI 1.5–2.6) and negatively with HPV33, 51, 52, and 66, in log-linear analysis. There was an excess of CIN3 diagnoses among subjects coinfected with HPV16 and HPV18 or HPV52, although the absolute number of cases was relatively small. In a logistic model, the odds ratio of CIN3+ associated with coinfection of HPV16 and HPV18 (OR = 3.8, 95% CI 2.5–5.7, p=0.004 compared to single HPV16) or HPV52 (OR = 3.6, 95% CI 2.6–5.1, p=0.009 compared to single HPV) was higher than that associated with single HPV 16 infections. Finally, multiple infections had no effect on residual disease and did not influence the recurrence of high-grade CIN during a median follow-up of 25 months (IR 17–41). HPV16 interacted positively with HPV18 and negatively with HPV33, 51, 52, and 66 supporting the notion that HPV16 interacts mostly negatively with other HR-HPVs in CIN lesions. Among specimens coinfected with HPV16 and 18 or 52, there was an excess of CIN3+ although the impact on the prevalence of severe cervical lesions was limited.

Common types of infection with multitypes of HPV on uterine cervix

Persistent infection by human papillomavirus (HPV) is an important factor causing cervical cancer. In recent years, infection with multiple HPV types has been confirmed in various studies. High-risk HPV 16 and 18 and low-risk HPV 6 are the most common causes of multitype HPV infection. Infection with multiple types of HPV, which results from individual susceptibility, is crucial in tumor susceptibility. This paper summarizes the common types of multiple HPV infection to enable further research on the relationship between HPV and tumor susceptibility.

Superinfection Exclusion between Two High-Risk Human Papillomavirus Types during a Coinfection

Superinfection exclusion is a common phenomenon whereby a single cell is unable to be infected by two types of the same pathogen. Superinfection exclusion has been described for various viruses, including vaccinia virus, measles virus, hepatitis C virus, influenza A virus, and human immunodeficiency virus. Additionally, the mechanism of exclusion has been observed at various steps of the viral life cycle, including attachment, entry, viral genomic replication, transcription, and exocytosis. Human papillomavirus (HPV) is the causative agent of cervical cancer. Recent epidemiological studies indicate that up to 50% women who are HPV positive (HPV⁺) are infected with more than one HPV type. However, no mechanism of superinfection exclusion has ever been identified for HPV. Here, we show that superinfection exclusion exists during a HPV coinfection and that it occurs on the cell surface during the attachment/entry phase of the viral life cycle. Additionally, we are able to show that the minor capsid protein L2 plays a role in this exclusion. This study shows, for the first time, that superinfection exclusion occurs during HPV coinfections and describes a potential molecular mechanism through which it occurs.IMPORTANCE Superinfection exclusion is a phenomenon whereby one cell is unable to be infected by multiple related pathogens. This phenomenon has been described for many viruses and has been shown to occur at various points in the viral life cycle. HPV is the causative agent of cervical cancer and is involved in other anogenital and oropharyngeal cancers. Recent epidemiological research has shown that up to 50% of HPV-positive individuals harbor more than one type of HPV. We investigated the interaction between two high-risk HPV types, HPV16 and HPV18, during a coinfection. We present data showing that HPV16 is able to block or exclude HPV18 on the cell surface during a coinfection. This exclusion is due in part to differences in the HPV minor capsid protein L2. This report provides, for the first time, evidence of superinfection exclusion for HPV and leads to a better understanding of the complex interactions between multiple HPV types during coinfections.

Human papillomavirus clustering patterns among HIV-infected and HIV-uninfected adolescent females in South Africa

The global burden of disease caused by both human immunodeficiency virus (HIV) and human papillomavirus (HPV) is the greatest in the developing world, with the highest rates in sub-Saharan Africa. South African women not only have high rates of infection with HPV, but also have high rates of multiple concurrent infections with two or more HPV genotypes, and are among the world's most vulnerable to developing invasive cervical cancer. HIV co-infection increases these risks. Understanding clustering patterns of concurrent HPV infections in this population has important implications for HPV screening and will help define vaccination strategies in the future as vaccines continue to be developed to target more HPV genotypes. Latent class analysis was used to identify four distinct patterns of HPV co-infection: individuals with at least one low risk HPV genotype, but no high-risk HPV (HR-HPV) infections; individuals with a disperse pattern of HR-HPV infections; individuals infected with members of the alpha-7 group, but not HPV-18; and individuals infected with HPV-16, but not HPV-18. In this analysis, although alpha-7 HPV infections were more prevalent among HIV-infected adolescents than their HIV-uninfected counterparts, overall clustering patterns were not different based on HIV status.

High prevalence of co-infection between human papillomavirus (HPV) 51 and 52 in Mexican population

Background

Human papillomavirus (HPV) is associated with the genesis of cervical carcinoma. The co-infection among HPV genotypes is frequent, but the clinical significance is controversial; in Mexico, the prevalence and pattern of co-infection differ depending on the geographic area of study. We analyzed the mono- and co-infection prevalence of multiple HPV genotypes, as well as preferential interactions among them in a Mexico City sample population.

Methods

This study was designed as a retrospective cohort study. Cervical cytology samples from 1163 women and 166 urethral scraping samples of men were analyzed between 2010 and 2012. The detection of HPV infection was performed using the hybrid capture and the genotyping was by PCR (HPV 6, 11, 16, 18, 30, 31, 33, 35, 45, 51, and 52).

Results

36% of women were HPV-positive and the most prevalent genotypes were HPV 51, 52, 16, and 33 (42, 38, 37, and 34%, respectively). The prevalence of co-infection was higher (75.37%) than mono-infection in women HPV positives. All genotypes were co-infected with HPV 16, but the co-infection with 51–52 genotypes was the most frequent combination in all cases.

Conclusion

The co-infection was very common; each HPV genotype showed different preferences for co-infection with other genotypes, HPV 51–52 co-infection was the most frequent. The HPV 16, 33, 51 and 52 were the most prevalent and are a public health concern to the Mexican population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3519-7) contains supplementary material, which is available to authorized users.

Human papillomavirus infection and p16 expression in the immunocompetent patients with extragenital/extraungual Bowen's disease

BACKGROUND

The role of human papillomaviruses (HPV) in the development of squamous cell carcinoma (SCC) has been established for anogenital lesions but still remains controversial for carcinomas in other sites. The aim of this study was to determine the α-HPV and β-HPV prevalence and their association with p16 expression, sun exposure, and clinicopathological findings in patients with Bowen's disease (BD).

METHODS

One hundred sixty nine skin biopsy specimens from 157 immunocompetent patients with extragenital/extraungual BD were examined for HPV status and p16 expression. The presence of koilocyte-like changes, solar elastosis and papillomatosis was recorded for each specimen.

RESULTS

BD was diagnosed more often in potentially sun-exposed sites with prevalence 73.6 % and a remarkable predilection for the head and neck region. High risk α-HPV or β-HPV were detected in 34.7 % of lesions and β-HPV infections dominated over α-HPV. Higher prevalence of koilocyte-like changes and papillomatosis was found in HPV-positive specimens but it was not statistically significant. The expression of p16 was detected in 79.8 % of lesions and displayed no correlation with the HPV status. HPV-positivity tended to be detected more often in sun-protected sites. Dual infections by α-HPV/β-HPV genera and mixed α-HPV infections were not detected, while 37.5 % of β-HPV positive specimens were infected by two or more β-HPV genotypes. HPV 9 was significantly associated with mixed β-HPV infections.

CONCLUSIONS

HPV may play an etiological role at least in some SCC in situ arising in extragenital sites. Sunprotected sites may be more dependent on HPV-mediated co-carcinogenesis than sun exposed areas. The presence of the p16-expression, papillomatosis or koilocyte-like change is not a reliable marker of HPV infection in SCC in situ.

Development of a fluorescence-based multiplex genotyping method for simultaneous determination of human papillomavirus infections and viral loads

Background

Persistent high-risk human papillomavirus (HPV) infection is correlated with an increased risk of developing intraepithelial lesion or malignancy (NILM). The aims of the current study is to establish a method named BioPerfectus Multiplex Real Time (BMRT) HPV assay for simultaneous typing and quantifying HPVs, and to evaluate it by comparison with HPV GenoArray test and PCR-sequencing method, as well as histological status.

Methods

A total of 817 cervical specimens were evaluated by BMRT method and HPV GenoArray test, using PCR-sequencing method as the reference standard; simultaneously, high-risk HPV-16 and -18 DNA loads were assessed in 443 specimens to investigate the correlation with infection outcomes.

Results

The overall detection coincidence rate between BMRT assay and HPV GenoArray test is 96.6 % and the Kappa value is 0.760. In addition, the sensitivity and positive predictive value of BMRT is 98.4 % and 95.7 % compared with the results detected by PCR-sequencing method, respectively. HPV-16 viral load has a correlation with CINs or worse lesions. By comparing with infected women presenting NILM /cervicitis, the cutoff value for HPV-16 from patients with CINs was 0.827. With this cutoff value, 74.6 % sensitivity and 72.5 % specificity for prediction of HPV-16 infected patients with CINI and higher CIN were achieved. High significance was obtained when comparing the infected women presenting NILM/cervicitis with women either with CIN and cervical carcinomas (p < 0.001).

Conclusions

The BMRT assay seemed to be a good alternative approach for HR-HPV testing, due to its high level of automation and ability to quantify HPV-16, HPV-18 and other HR-HPVs.

Impact of human papillomavirus coinfections on the risk of high-grade squamous intraepithelial lesion and cervical cancer

OBJECTIVE

The molecular and epidemiologic effect of human papillomavirus (HPV) coinfections in the risk of developing cervical cancer is yet unclear. The aim of this study was to determine the frequency HPV coinfections at different stages of cervical lesions in the development of cervical cancer and the impact of HPV specific type interactions on high-grade squamous intraepithelial lesions (HSIL) and invasive cervical cancer (ICC) risk.

METHODS

HPV testing was performed in 931 cervical samples diagnosed as: negative for intraepithelial lesion or malignancy (NILM); low-grade squamous intraepithelial lesion (LSIL); HSIL; and ICC. For HPV detection and typing two sets of primers from the L1 region were used in the polymerase chain reaction method (PCR) (MY09/MY11/HMB01 and L1C1/L1C2.1/L1C2.2) and HPV type was determined by PCR product sequence. To look for multiple HPV infections, the E6 nested multiplex PCR method was performed in all DNA samples. Odds ratios were calculated as indexes of the strength of the association between the sample category (LSIL/NILM or ICC/HSIL) and the presence of a given viral combination.

RESULTS

In HPV positive samples, coinfections are as common in ICC/HSIL as in LSIL/NILM (47.12% and 40.17%, respectively). There is an increased risk to ICC/HSIL when multiple high-risk HPV types are present. The coinfection of HPV68 with HPV16 increases the risk of ICC/HSIL (OR=14.54, P=0.012, after multivariate adjustment), related to the presence of HPV16 or HPV68 alone.

CONCLUSIONS

These results sustain that specific HPV coinfections confer an increased risk to develop ICC/HSIL.

Population- and type-specific clustering of multiple HPV types across diverse risk populations in the Netherlands

In view of possible type replacement upon introduction of human papillomavirus (HPV) vaccination, we aimed to explore patterns of type-specific clustering across populations with various background infection risks. A total of 3,874 women from 3 cross-sectional studies in the Netherlands (in 2007-2009) provided vaginal self-samples, which were tested for 25 HPV genotypes by a sensitive molecular assay (SPF10 line probe assay, DDL Diagnostic Laboratory, Voorburg, the Netherlands). The number of concurrent HPV infections per woman was studied by Poisson regression. Associations between HPV types were investigated by generalized estimating equation analyses. The prevalence of any HPV type was 14% in a population-based study, 54% in a chlamydia screening intervention study, and 73% in a study among attendees of sexually transmitted infection clinics. Overall, multiple HPV infections were detected in 26% of the women. The number of concurrent HPV infections conformed to an overdispersed Poisson distribution, even after correction for known risk factors. Types differed significantly in their tendencies to be involved in coinfections, but no evidence for particular type-type interactions was found. Moreover, the strongest associations were observed in the lowest-risk population and vice versa.We found no indications of pairwise interactions, but our findings do suggest that clustering differs among HPV types and varies across risk groups.

Prognostic value of DNA and mRNA e6/e7 of human papillomavirus in the evolution of cervical intraepithelial neoplasia grade 2

OBJECTIVE

This study aimed at evaluating whether human papillomavirus (HPV) groups and E6/E7 mRNA of HPV 16, 18, 31, 33, and 45 are prognostic of cervical intraepithelial neoplasia (CIN) 2 outcome in women with a cervical smear showing a low-grade squamous intraepithelial lesion (LSIL).

METHODS

This cohort study included women with biopsy-confirmed CIN 2 who were followed up for 12 months, with cervical smear and colposcopy performed every three months.

RESULTS

Women with a negative or low-risk HPV status showed 100% CIN 2 regression. The CIN 2 regression rates at the 12-month follow-up were 69.4% for women with alpha-9 HPV versus 91.7% for other HPV species or HPV-negative status (P < 0.05). For women with HPV 16, the CIN 2 regression rate at the 12-month follow-up was 61.4% versus 89.5% for other HPV types or HPV-negative status (P < 0.05). The CIN 2 regression rate was 68.3% for women who tested positive for HPV E6/E7 mRNA versus 82.0% for the negative results, but this difference was not statistically significant.

CONCLUSIONS

The expectant management for women with biopsy-confirmed CIN 2 and previous cytological tests showing LSIL exhibited a very high rate of spontaneous regression. HPV 16 is associated with a higher CIN 2 progression rate than other HPV infections. HPV E6/E7 mRNA is not a prognostic marker of the CIN 2 clinical outcome, although this analysis cannot be considered conclusive. Given the small sample size, this study could be considered a pilot for future larger studies on the role of predictive markers of CIN 2 evolution.

Revising ecological assumptions about Human papillomavirus interactions and type replacement

The controversy over whether vaccine-targeted HPV types will be replaced by other oncogenic, non-vaccine-targeted types remains unresolved. This is in part because little is known about the ecology of HPV types. Patient data has been interpreted to suggest independence or facilitative interactions between types and therefore replacement is believed to be unlikely. With a novel mathematical model, we investigated which HPV type interactions and their immune responses gave qualitatively similar patterns frequently observed in patients. To assess the possibility of type replacement, vaccination was added to see if non-vaccine-targeted types increased their 'niche'. Our model predicts that independence and facilitation are not necessary for the coexistence of types inside hosts, especially given the patchy nature of HPV infection. In fact, independence and facilitation inadequately represented co-infected patients. We found that some form of competition is likely in natural co-infections. Hence, non-vaccine-targeted types that are not cross-reactive with the vaccine could spread to more patches and can increase their viral load in vaccinated hosts. The degree to which this happens will depend on replication and patch colonization rates. Our results suggest that independence between types could be a fallacy, and so without conclusively untangling HPV within-host ecology, type replacement remains theoretically viable. More ecological thinking is needed in future studies.

Randomization modeling to ascertain clustering patterns of human papillomavirus types detected in cervicovaginal samples in the United States

Detection of multiple human papillomavirus (HPV) types in the genital tract is common. Associations among HPV types may impact HPV vaccination modeling and type replacement. The objectives were to determine the distribution of concurrent HPV type infections in cervicovaginal samples and examine type-specific associations. We analyzed HPV genotyping results from 32,245 cervicovaginal specimens collected from women aged 11 to 83 years in the United States from 2001 through 2011. Statistical power was enhanced by combining 6 separate studies. Expected concurrent infection frequencies from a series of permutation models, each with increasing fidelity to the real data, were compared with the observed data. Statistics were computed based on the distributional properties of the randomized data. Concurrent detection occurred more than expected with 0 or ≥3 HPV types and less than expected with 1 and 2 types. Some women bear a disproportionate burden of the HPV type prevalence. Type associations were observed that exceeded multiple hypothesis corrected significance. Multiple HPV types were detected more frequently than expected by chance and associations among particular HPV types were detected. However vaccine-targeted types were not specifically affected, supporting the expectation that current bivalent/quadrivalent HPV vaccination will not result in type replacement with other high-risk types.

Patterns of cervical coinfection with multiple human papilloma virus types in a screening population in Denmark

Patterns of cervical human papillomavirus (HPV) infection suggest that HPV genotypes are not independent of each other. This may be explained by risk factors common to all HPV infections, but type-specific biological factors may also play a role. This raises the question of whether widespread use of the quadrivalent vaccine (covering HPV6, 11, 16, 18) may indirectly affect the prevalence of any non-vaccine types. Routine screening samples from 5014 Danish women were tested for 35 HPV genotypes (including 13 high-risk) using the Genomica CLART(®) HPV2 kit, which is a low-density microarray based on PCR amplification. Simulation studies were performed both under independence between genotypes and under a common dependence structure as would arise from common risk factors, and simulation results were compared to observed coinfection patterns. Overall HPV prevalence was 37.4%, with multiple infections in 17.9%. For 15 HPV types of primary interest (13 high-risk plus HPV6, 11), almost all pairs occurred more often than expected under independence; 33/105 (31.4%) were statistically significant (p<0.05 after adjustment for multiple comparisons). The pairwise odds ratios showed significant heterogeneity (Woolf's test p<0.0001). For simulations based on common dependence, three pairs had observed to expected (O/E) ratios significantly different than 1 (31/68, O/E=4.20; 51/68, O/E=2.52; 33/58, O/E=3.27; all p<0.05 after adjustment for multiple comparisons). HPV68 occurred in multiple infections nearly four times as often as expected under common dependence (p<0.005 after adjustment for multiple comparisons). These results indicate some interaction between HPV types, and suggest that common risk factors do not entirely explain the observed HPV coinfection pattern, although no evidence is found that the prevalence of any types not targeted by the quadrivalent vaccine may be indirectly increased or decreased after widespread use of the vaccine.

Exploring individual HPV coinfections is essential to predict HPV-vaccination impact on genotype distribution: a model-based approach

INTRODUCTION

As for other vaccines that only target a subset of circulating pathogen types, human papillomavirus (HPV) immunization raises the concern of a potential risk of genotype replacement. Potential interactions between HPV types may affect infection acquisition and clearance. However, the existence and the nature of these interactions are still largely unknown. Here, we assess how such interactions might affect the impact of HPV vaccination on genotype distribution in the long term.

METHODS

We develop two mathematical models of the transmission of oncogenic HPV infections that include interactions between vaccine and nonvaccine genotypes to examine the influence of different coinfection dynamics (simultaneous vs. sequential clearance of coinfections) on the evolution of nonvaccine prevalences postimmunization.

RESULTS

After introducing vaccination, the two models give contrasting genotype-replacement outcomes. When hypothesizing that coinfections clear sequentially, genotype replacement depends on whether vaccine and nonvaccine genotypes reduce or favor the acquisition by one or the other. Interestingly, the hypothesis that coinfections clear simultaneously always leads to genotype replacement, even when infections with vaccine types favor the acquisition of infections with nonvaccine types.

CONCLUSION

Our results suggest that predictions regarding HPV genotype replacement strongly depend on the assumptions describing the dynamics (acquisition and clearance) of coinfections. In particular, HPV genotype replacement could be compatible with synergistic interactions between types affecting infections acquisition, contrary to previous suggestions. Understanding better how concurrent infections with multiple types change the acquisition and time to clearance of type-specific infections is essential to be able to predict the impact of vaccination on genotype distribution. Longitudinal data collection in populations, particularly examining infection and coinfection acquisition and clearance, is needed to better predict HPV-vaccine impact.

Development of a bead-based multiplex genotyping method for diagnostic characterization of HPV infection

The accurate genotyping of human papillomavirus (HPV) is clinically important because the oncogenic potential of HPV is dependent on specific genotypes. Here, we described the development of a bead-based multiplex HPV genotyping (MPG) method which is able to detect 20 types of HPV (15 high-risk HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68 and 5 low-risk HPV types 6, 11, 40, 55, 70) and evaluated its accuracy with sequencing. A total of 890 clinical samples were studied. Among these samples, 484 were HPV positive and 406 were HPV negative by consensus primer (PGMY09/11) directed PCR. The genotyping of 484 HPV positive samples was carried out by the bead-based MPG method. The accuracy was 93.5% (95% CI, 91.0–96.0), 80.1% (95% CI, 72.3–87.9) for single and multiple infections, respectively, while a complete type mismatch was observed only in one sample. The MPG method indiscriminately detected dysplasia of several cytological grades including 71.8% (95% CI, 61.5–82.3) of ASCUS (atypical squamous cells of undetermined significance) and more specific for high grade lesions. For women with HSIL (high grade squamous intraepithelial lesion) and SCC diagnosis, 32 women showed a PPV (positive predictive value) of 77.3% (95% CI, 64.8–89.8). Among women >40 years of age, 22 women with histological cervical cancer lesions showed a PPV of 88% (95% CI, 75.3–100). Of the highest risk HPV types including HPV-16, 18 and 31 positive women of the same age groups, 34 women with histological cervical cancer lesions showed a PPV of 77.3% (95% CI, 65.0–89.6). Taken together, the bead-based MPG method could successfully detect high-grade lesions and high-risk HPV types with a high degree of accuracy in clinical samples.

Type-dependent E6/E7 mRNA expression of single and multiple high-risk human papillomavirus infections in cervical neoplasia

BACKGROUND

Coinfection with multiple HPV types is common in cervical lesions, but the biological significance of the individual infections is difficult to establish. Expression of oncogenic E6/E7 HPV mRNA is correlated to risk of malignant progression, commercial assays for genotyping E6/E7 mRNA of all HR-HPV are lacking.

OBJECTIVES

To characterize the tendency of 12 HR-HPV to express mRNA, correlated to the severity of the cervical lesion. Furthermore, we wanted to analyse mRNA expression in multiple infections, in order to establish which genotype may be responsible for cellular transformation.

STUDY DESIGN

245 samples from women with normal histology, various grades of dysplasia (cervical intraepithelial neoplasia grade 1-3), and cancer, were analysed for presence and genotyping of HPV DNA and mRNA using an in house real-time PCR test.

RESULTS

Presence of mRNA was detected for 64% of the in total 422 HPV infections present in the samples, and more commonly in high-grade lesions. In 88% of DNA-positive samples from CIN2+ lesions, mRNA could be detected, compared to 33% of DNA-positive samples from women in screening with normal cytology. The genotype most prone to express mRNA in high-grade lesions was HPV45, followed by HPV16 and HPV31, less prone was HPV59. Expression of mRNA was significantly enhanced in CIN2+ lesions, an association also found for HPV16. In 52% of multiple infections (in which mRNA expression was generally more common), more than one genotype expressed mRNA, a phenomenon increasing with severity of lesion. Presence of mRNA could more often be detected in samples with multiple infections than in samples with single infections.

CONCLUSIONS

The frequent expression of E6/E7 by HPV45 may promote oncogenicity and could be of clinical importance. Since presence of E6/E7 mRNA was common in multiple infections regardless of histology, multiple infection could be a clinically important finding. In multiple HPV infections, mRNA testing may identify the genotype that causes transformation. However, since mRNA expression of several genotypes in one sample is common, further and larger studies using complementary techniques are required.

Multiple human papillomavirus infections and type competition in men

BACKGROUND

There is little information on multiple human papillomavirus (HPV) infections and the potential for type competition in men, yet competition may impact the type-specific efficacy of HPV vaccination.

METHODS

Among 2702 uncircumcised men in Kisumu, Kenya, who were seronegative for human immunodeficiency virus, the observed numbers of HPV types detected were compared with the expected number, which was simulated under the assumption of independent infections. To assess the potential for HPV type competition, adjusted odds ratios for pairwise combinations of prevalent HPV type infections were estimated using semi-Bayesian methods.

RESULTS

Half of all men were HPV positive, of whom 57% had multiple HPV types. We observed men without HPV infection and with ≥4 HPV types more often than expected if infections were independent. No negative associations between individual HPV types were observed. HPV types 31, 39, 56, 58, and 59 were positively associated with both carcinogenic vaccine types HPV-16 and HPV-18 (2-sided P value <.05).

CONCLUSIONS

Men who were HPV infected were likely to test positive for >1 HPV type. Cross-sectional associations between individual HPV types were positive and did not appear to be type-specific. Thus, we did not identify HPV types that are candidates for potential HPV type competition in men.

An analysis of clustering of betapapillomavirus antibodies

Betapapillomaviruses (betaPVs) may contribute to the aetiology of cutaneous squamous cell carcinoma. However, no high-risk types have yet been identified, possibly because the high frequency of co-infection prevents a straightforward analysis of the independent effects of individual viruses. This study aimed to determine whether specific virus types were more likely to co-occur than others, thereby reducing the number of parameters needed in statistical models. Antibody data were analysed from controls who participated in case-control studies in The Netherlands, Italy and Australia and from participants in the German Nutrition Survey. Cluster analysis and two ordination techniques were used to identify patterns. Evidence of clustering was found only according to the number of viruses to which antibodies were detected. The lack of clustering of specific viral types identified suggests that if there are betaPV types that are independently related to skin carcinogenesis, they are unlikely to be identified using standard epidemiological methods.

Human papillomavirus genotypes in asymptomatic young women from public schools in Rio de Janeiro, Brazil

INTRODUCTION: The aim of this work was to survey HPV information from a random population of young women from Rio de Janeiro, Brazil. METHODS: This cross-sectional study included cervical samples from 241 female students. To determine human papillomavirus status, polymerase chain reaction amplification was performed. HPV typing was determined by restriction fragment length polymorphism analysis. Demographic data, life style, sexual and gynecological history were obtained through use of a structured questionnaire. RESULTS: The average age of the women was 19.6 years-old (SD=3.4 years). HPV prevalence was 27.4%. Nineteen different HPV genotypes were detected, including 13 high risk types. HPV 16 was the most prevalent type (6.2%), followed by 31 (4.1 %) and 66 (3.7%). Most of the oncogenic types belonged to the A9 species (28/48). The frequency of women infected by at least one oncogenic type was significantly higher than those only infected by low risk types (18.7% versus 7.5%). Cervical changes were detected in 12.5% of the sample and were significantly linked to infection with HPV types of the A9 species. Demographic variables, sexual initiation, or number of sexual partners were not associated with HPV prevalence, variety of HPV genotypes or oncogenic types. CONCLUSIONS: The relative frequency of HPV genotypes other than vaccine types in young females should be taken into account when evaluating vaccination strategies. Due to the high prevalence of HPV infection among the population studied, implementation of sex education in schools, promotion of condom use and an organized screening program to prevent cervical cancer must be encouraged for this age group.