No evidence for a protective effect of naturally induced HPV antibodies on subsequent anogenital HPV infection in HIV-negative and HIV-infected MSM

Association of naturally acquired type-specific HPV antibodies and subsequent HPV re-detection: systematic review and meta-analysis

BACKGROUND

Understanding the role of naturally acquired (i.e., infection-induced) human papillomavirus (HPV) antibodies against reinfection is important given the high incidence of this sexually transmitted infection. However, the protective effect of naturally acquired antibodies in terms of the level of protection, duration, and differential effect by sex remains incompletely understood. We conducted a systematic review and a meta-analysis to (1) strengthen the evidence on the association between HPV antibodies acquired through past infection and subsequent type-specific HPV detection, (2) investigate the potential influence of type-specific HPV antibody levels, and (3) assess differential effects by HIV status.

METHODS

We searched Embase and Medline databases to identify studies which prospectively assessed the risk of type-specific HPV detection by baseline homologous HPV serostatus among unvaccinated individuals. Random-effect models were used to pool the measures of association of naturally acquired HPV antibodies against subsequent incident detection and persistent HPV positivity. Sources of heterogeneity for each type were assessed through subgroup analyses stratified by sex, anatomical site of infection, male sexual orientation, age group, and length of follow-up period. Evidence of a dose-response relationship of the association between levels of baseline HPV antibodies and type-specific HPV detection was assessed. Finally, we pooled estimates from publications reporting associations between HPV serostatus and type-specific HPV detection by baseline HIV status.

RESULTS

We identified 26 publications (16 independent studies, with 62,363 participants) reporting associations between baseline HPV serostatus and incident HPV detection, mainly for HPV-16 and HPV-18, the most detected HPV type. We found evidence of protective effects of baseline HPV seropositivity and subsequent detection of HPV DNA (0.70, 95% CI 0.61-0.80, NE = 11) and persistent HPV positivity (0.65, 95% CI 0.42-1.01, NE = 5) mainly for HPV-16 among females, but not among males, nor for HPV-18. Estimates from 8 studies suggested a negative dose-response relationship between HPV antibody level and subsequent detection among females. Finally, we did not observe any differential effect by baseline HIV status due to the limited number of studies available.

CONCLUSION

We did not find evidence that naturally acquired HPV antibodies protect against subsequent HPV positivity in males and provide only modest protection among females for HPV-16. One potential limitation to the interpretation of these findings is potential misclassification biases due to different causes.

Reinfection of Nine-Valent Human Papillomavirus Vaccine Types Among HIV-Negative Men Who Have Sex With Men: A Prospective Cohort Study

Objectives

Reinfection of human papillomavirus (HPV) among men who have sex with men (MSM) after clearing the infection of HPV has not been well characterized. To understand the reinfection of HPV among human immunodeficiency virus (HIV) negative MSM without HPV vaccine, we analyzed the reinfection of nine-valent HPV vaccine (9v-HPV) types.

Methods

Data were acquired from a prospective cohort study among HIV-negative MSM in Urumqi of Xinjiang from 1 April 2016 to 14 July 2020. Participants were recruited through a local non-government organization using a website advertisement. Self-administered questionnaires and self-collected anal swabs were collected at baseline and every 6 months. The incidence rates of reinfection was calculated based on the number of events divided by person-months of observation of event risk. 95% confidence intervals (CIs) were calculated based on the Poisson distribution.

Results

A total of 515 HIV-negative unvaccinated MSM were included with a mean age of 30.93 years (SD 7.85), and 27.68% were reinfected with any 9v-HPV type after clearance. The reinfection incidence rate of any 9v-HPV was 14.47 per 1000 person-months (95% CI: 11.52–17.87). HPV52 was the most common type of reinfection, with a reinfection rate of 17.96 per 1,000 person months (95% CI: 11.58–26.33). Univariate analysis showed that MSM over the age of 30 had a slightly higher risk of reinfection with any 9v-HPV (Hazard ratio (HR): 1.57; 95% CI: 1.01–2.45), but no significant association was observed in multivariate analysis.

Conclusions

Our study showed MSM without HPV vaccine will become reinfected following the natural clearance of specific HPV types. It is also suggested that HPV vaccination is recommended not only prior to sexual debut but also after viral clearance for MSM to reduce HPV prevalence.

Human Papillomavirus Seroprevalence and Seroconversion Among Men Living With HIV: Cohort Study in South Africa

BACKGROUND

Men living with HIV (MLHIV) have a high burden of human papillomavirus (HPV)-related cancer. Understanding serological dynamics of HPV in men can guide decisions on introducing HPV vaccination and monitoring impact. We determined HPV seroprevalence and evaluated factors associated with HPV seroconversion among MLHIV in Johannesburg, South Africa.

METHODS

We enrolled 304 sexually active MLHIV 18 years and older and collected sociobehavioral data, blood samples (CD4 counts, HIV-1 plasma viral load, and HPV serology), and genital and anal swabs [HPV DNA and HPV viral load (VL)] at enrollment and 6-monthly for up to 18 months. Antibodies to 15 HPV types were measured using HPV pseudovirions. Generalized estimating equations were used to evaluate correlates of HPV seroconversion.

RESULTS

Median age at enrollment was 38 years (IQR: 22-59), 25% reported >1 sexual partner in the past 3 months, and 5% reported ever having sex with other men. Most participants (65%) were on antiretroviral therapy (ART), with median CD4 count of 445 cells/µL (IQR: 328-567). Seroprevalence for any HPV type was 66% (199/303). Baseline seropositivity for any bivalent (16/18), quadrivalent (6/11/16/18), and nonavalent (6/11/16/18/31/33/45/52/58) vaccine types was 19%, 37%, and 60%, respectively. At 18 months, type-specific seroconversion among 59 men whose genital samples were HPV DNA positive but seronegative for the same type at enrollment was 22% (13/59). Type-specific seroconversion was higher among men with detectable HIV plasma viral load (adjusted odds ratio = 2.78, 95% CI: 1.12 to 6.77) and high HPV VL (adjusted odds ratio = 3.32, 95% CI: 1.42 to 7.74).

CONCLUSIONS

Seropositivity and exposure to nonavalent HPV types were high among MLHIV. HPV vaccination of boys before they become sexually active could reduce the burden of HPV infection among this at-risk population.

Natural and vaccine-induced B cell-derived systemic and mucosal humoral immunity to human papillomavirus

Introduction: Human papillomavirus (HPV) are the causative agent of mucosal neoplasia. Both cervical, anal and oropharyngeal cancers incidence is constantly increasing, making the HPV infection, a significant worldwide concern. Together, the CD8+ T cytotoxic cell-mediated response and the HPV-specific antibody response control most of the HPV infections before the development of cancers.Areas covered: We searched the MEDLINE and EMBASE databases and identified 228 eligible studies from 1987 to 2019 which examines both naturally acquired and vaccine induced humoral immunity against HPV infection in female and male subjects from worldwide origin. Herein, we synthesize current knowledge on the features of systemic and mucosal humoral immunity against HPV. We discuss the issues of the balance between the viral clearance or the escape to the host immune response, the differences between natural and vaccine-induced HPV-specific antibodies and their neutralizing capability. We also discuss the protection afforded after natural infection or following prophylactic vaccination.Expert opinion: Understanding the antibody response induced by HPV infection has led to the design of first-generation prophylactic vaccines. Now, prophylactic vaccination induces protective and long-lasting antibody response which would also strengthened the natural moderate humoral response in people previously exposed to the virus.

HPV infections among young MSM visiting sexual health centers in the Netherlands: Opportunities for targeted HPV vaccination

INTRODUCTION

In 2009, girls-only HPV16/18 vaccination was introduced in the Netherlands which has achieved 46-61% uptake. Heterosexual men have benefitted from herd protection, but it is unknown whether men who have sex with men (MSM) also benefit from herd effects of the girls-only HPV16/18 vaccination program. Because MSM bear a high HPV-related disease burden, countries might consider targeted vaccination for MSM. To study possible herd effects and prior HPV exposure at a potential moment of vaccination, we assessed trends in the HPV prevalence and proportions (sero)negative for the various vaccine types among young MSM visiting sexual health centers (SHCs).

METHODS

We used data from MSM included in PASSYON study years 2009-2017. In this biennial cross-sectional study among visitors of SHCs aged 16-24 years, MSM provided a penile and anal swab for HPV DNA testing (including vaccine types HPV6/11/16/18/31/33/45/52/58) and blood for HPV antibody testing (HPV16/18/31/33/45/52/58).

RESULTS

In total 575 MSM were included, with a median of 22 years of age and 15 lifetime sex partners and 3.5% HIV positive. Trends in penile or anal HPV prevalence during 2009-2017 were statistically non-significant for all vaccine types. Of the 455 MSM with a penile and anal swab, 360 (79%), 283 (62%) and 242 (53%) were HPV DNA negative at both anatomical sites for HPV16/18, HPV6/11/16/18 and HPV6/11/16/18/31/33/45/52/58 respectively. Among MSM who were HPV16/18 and HPV16/18/31/33/45/52/58 DNA negative and were tested for serology (n = 335 and 279 respectively), 82% and 71% were also seronegative for the respective types.

DISCUSSION

There were no significant declines in the HPV prevalence among MSM up to eight years after introduction of girls-only HPV16/18 vaccination, indicating that MSM are unlikely to benefit largely from herd effects from girls-only vaccination. Most MSM were vaccine-type DNA negative and seronegative, suggesting that vaccination of young MSM visiting SHCs could still be beneficial.

An Examination of HPV16 Natural Immunity in Men Who Have Sex with Men (MSM) in the HPV in Men (HIM) Study

Background: Evidence suggests that natural antibodies developed after HPV16 infection may protect some women but not men against subsequent HPV16 reacquisition. Less is known whether antibodies developed following HPV16 infection are protective among men who have sex with men (MSM).Methods: Four hundred seventy-five MSM from the Human Papillomavirus Infection in Men (HIM) study were tested for serum antibodies to HPV16 L1 using enzyme-linked immunosorbent assays, and for anal and genital HPV16 DNA using PCR consensus primer system (PGMY 09/11). Adjusted Cox regression was used to evaluate whether baseline HPV16 seropositivity impacts subsequent genital or anal HPV16 DNA.Results: The risk of subsequent genital HPV16 [aHR = 1.05, 95% confidence interval (CI) = 0.66-1.68] and anal HPV16 infections among MSM (aHR = 2.34, 95% CI = 0.92-5.98) was similar or nonsignificantly higher in HPV16-seropositive than HPV16-seronegative MSM. The risk of genital HPV16 was also similar between HPV16-seronegative and HPV16-seropositive MSM in the highest tertile of HPV16 antibody levels and when restricting to those with new sex partners during follow-up (P > 0.20). Among the 118 MSM who were HPV16 seropositive, 90% remained HPV16 seropositive up to 4 years later. When tested together, MSM with the highest antibody titers (top tertile) had similar levels to females (mean = 130.3 vs. 134.5 EU/mL, P = 0.84).Conclusions: Despite years of HPV16 seropositivity persistence and antibody titers comparable with females, this study suggested no evidence of HPV16 natural antibodies protecting against subsequent genital or anal HPV16 infection in MSM.Impact: This could help partially explain the high incidence of genital and anal HPV16 infection and related anal cancer seen in middle-aged and older MSM. Cancer Epidemiol Biomarkers Prev; 27(4); 496-502. ©2018 AACR.

Causal role of infectious agents in cancer: An overview

Cancer is a complex group of diseases with multiple eventual causes. The underlying causes are not fully known. Thus, learning more about the known causes of cancer is an important issue. Moreover, among these factors, infection and its association to cancers is controversial. Although, it seems that the genome instability of the cells can initiate cancer development. The purpose of this review was to present the role of infection in the development of cancer. Infectious agents, such as hepatitis B (HBV) and C viruses (HCV), Epstein-Barr virus (EBV), human papillomavirus (HPV), human immunodeficiency virus type 1 (HIV-1), Helicobacter pylori (H. pylori) and Streptococcus bovis (S. bovis) contribute to the pathogenesis of different cancers. These cancers include hepatocellular carcinoma, Burkitt's lymphoma, nasopharyngeal carcinoma, cervical cancers, non-Hodgkin lymphoma, Kaposi sarcoma, adenocarcinoma and lymphoma. Screenings of infectious diseases in cancer patients may open up areas of research in the identification of optimizing cancer control strategies.

Impact of Serum Antibodies to HPV Serotypes 6, 11, 16, and 18 to Risks of Subsequent Genital HPV Infections in Men: The HIM Study

Naturally induced serum antibodies against human papillomavirus (HPV) may affect risks of subsequent incident genital infections by HPV 6, 11, 16, or 18 in men. In this study, we examined the hypothesis by following 4,123 healthy men every 6 months (median follow-up time, 4.1 years). HPV antibodies were measured at baseline using a virus-like particle-based ELISA assay. Genital HPV genotypes were detected using Roche Linear Array. Incidence proportions and 6-month persistence proportions were calculated at 6-month intervals. Kaplan-Meier curves and Cox models were used to assess genotype-specific cumulative incidence and HRs, respectively. HPV 6, 11, 16, and 18 seroprevalence was 8.1%, 13.9%, 12.7%, and 10.8%, respectively. Significantly higher rates of incident infections were observed for HPV 16 among baseline-seropositive men [adjusted HR, 1.37; 95% confidence interval (CI), 1.01-1.86], with similar but nonsignificant HRs for 6-month persistent infections. Risk of persistent HPV 18 infection was significantly lower among seropositive men in the unadjusted model (HR, 0.22; 95% CI, 0.06-0.91), but not in the adjusted model (HR, 0.19; 95% CI, 0.03-1.37). Incident and 6-month persistent infections for HPV 6 and 11 did not differ by baseline serostatus. Baseline serostatus among men was not associated with a reduction in subsequent incident genital HPV 6, 11, and 16 infections. However, protection against persistent HPV18 infections was observed in unadjusted models. Our research suggests a need of further studies to examine the potentially protective effects of naturally induced HPV18 antibodies in men. Cancer Res; 76(20); 6066-75. ©2016 AACR.

Monitoring for Human Papillomavirus Vaccine Impact Among Gay, Bisexual, and Other Men Who Have Sex With Men-United States, 2012-2014

BACKGROUND

Gay, bisexual, and other men who have sex with men (MSM) are at high risk for human papillomavirus (HPV) infection; vaccination is recommended for US males, including MSM through age 26 years. We assessed evidence of HPV among vaccine-eligible MSM and transgender women to monitor vaccine impact.

METHODS

During 2012-2014, MSM aged 18-26 years at select clinics completed a computer-assisted self-interview regarding sexual behavior, human immunodeficiency virus (HIV) status, and vaccinations. Self-collected anal swab and oral rinse specimens were tested for HPV DNA (37 types) by L1 consensus polymerase chain reaction; serum was tested for HPV antibodies (4 types) by a multiplexed virus-like particle-based immunoglobulin G direct enzyme-linked immunosorbent assay.

RESULTS

Among 922 vaccine-eligible participants, the mean age was 23 years, and the mean number of lifetime sex partners was 37. Among 834 without HIV infection, any anal HPV was detected in 69.4% and any oral HPV in 8.4%, yet only 8.5% had evidence of exposure to all quadrivalent vaccine types. In multivariate analysis, HPV prevalence varied significantly (P < .05) by HIV status, sexual orientation, and lifetime number of sex partners, but not by race/ethnicity.

DISCUSSIONS

Most young MSM lacked evidence of current or past infection with all vaccine-type HPV types, suggesting that they could benefit from vaccination. The impact of vaccination among MSM may be assessed by monitoring HPV prevalence, including in self-collected specimens.

Antibody responses following incident anal and penile infection with human papillomavirus in teenage men who have sex with men

Men who have sex with men (MSM) are at risk for human papillomavirus (HPV)-related anal cancer. Few data exist on antibody responses following incident anogenital infection with HPV in teenage MSM. A cohort of 200 MSM aged 16-20 years from Melbourne, Australia were assessed at baseline, 3, 6 and 12 months. At each visit anal and penile swabs were collected for HPV DNA and serum for HPV antibodies for genotypes 6, 11, 16 and 18 (Merck's Multiplex Assays using Luminex). The main outcome, seroconversion, was defined as the detection of HPV antibodies following a negative antibody result for the same HPV type at baseline. The seroincidence rates for HPV types 6, 11, 16 and 18 were: 19 (95% CI 12-26), 7 (3-12), 4 (1-8) and 6 (3-11) per 100 person-years, respectively. Men who experienced incident anal HPV infections from types 6/11 were significantly more likely to develop serum antibodies to the same HPV type(s) than those who experienced incident anal infections from types 16/18 [73 vs. 18%, odds ratio (OR) = 15, 95% CI: 2-118]. The median time between incident anal HPV infection and seroconversion for HPV 6, 11, 16 and 18 was: 91, 38, 161 and 182 days, respectively. Antibody responses against HPV types 6/11 were significantly more likely to occur following incident anal compared with incident penile infection with HPV types 6/11 (OR = 6, 95% CI: 2-21). The likelihood of antibody responses following anogenital HPV infections depends on the HPV type and site of infection.

Human Papillomavirus (HPV) L1 Serum Antibodies and the Risk of Subsequent Oral HPV Acquisition in Men: The HIM Study

The role of antibody-mediated immunity in preventing newly acquired oral human papillomavirus (HPV) is not well understood. Among 1618 men participating in the HPV Infection in Men (HIM) Study, we evaluated oral rinses for HPV DNA and baseline sera for HPV-6, -11, -16, and -18 L1 antibodies. Thirty percent of men (486) were seropositive for ≥1 HPV type, and 25 men developed incident oral HPV infection (HPV-6 was detected in 7, HPV-11 in 0, HPV-16 in 17, and HPV-18 in 1). Cox models revealed that men with circulating antibodies to HPV-6, -11, -16, or -18 were not less likely to acquire type-specific oral HPV than men without antibodies (hazard ratio for the risk of acquiring HPV-6, -11, -16, or -18, 1.63; 95% confidence interval, .56-4.76).

Natural Acquired Immunity Against Subsequent Genital Human Papillomavirus Infection: A Systematic Review and Meta-analysis

BACKGROUND

Studies have been mixed on whether naturally acquired human papillomavirus (HPV) antibodies may protect against subsequent HPV infection. We performed a systematic review and meta-analysis to assess whether naturally acquired HPV antibodies protect against subsequent genital HPV infection (ie, natural immunity).

METHODS

We searched the MEDLINE and EMBASE databases for studies examining natural HPV immunity against subsequent genital type-specific HPV infection in female and male subjects. We used random-effects models to derive pooled relative risk (RR) estimates for each HPV type.

RESULTS

We identified 14 eligible studies that included >24,000 individuals from 18 countries that examined HPV natural immunity. We observed significant protection against subsequent infection in female subjects with HPV-16 (pooled RR, 0.65; 95% confidence interval, .50-.80) and HPV-18 (0.70; .43-.98) but not in male subjects (HPV-16: 1.22; .67-1.77 [P= .05 (test for heterogeneity)]; HPV-18: 1.50; .46-2.55; [P= .15]). We also observed type-specific protection against subsequent infection for a combined measure of HPV-6/11/31/33/35/45/52/58 in female subjects (pooled RR, 0.75; 95% confidence interval, .57-.92). Natural immunity was also evident in female subjects when analyses were restricted to studies that used neutralizing assays, used HPV persistence as an outcome, or reported adjusted analyses (each P< .05).

CONCLUSIONS

HPV antibodies acquired through natural infection provide modest protection against subsequent cervical HPV infection in female subjects.

Seroconversion Following Anal and Genital HPV Infection in Men: The HIM Study

Background

Protection from naturally acquired human papillomavirus (HPV) antibodies may influence HPV infection across the lifespan. This study describes seroconversion rates following genital, anal, and oral HPV 6/11/16/18 infections in men and examines differences by HPV type and anatomic site.

Methods

Men with HPV 6/11/16/18 infections who were seronegative for those genotypes at the time of DNA detection were selected from the HPV Infection in Men (HIM) Study. Sera specimens collected ≤36 months after detection were analyzed for HPV 6/11/16/18 antibodies using a virus-like particle-based ELISA. Time to seroconversion was separately assessed for each anatomic site, stratified by HPV type.

Results

Seroconversion to ≥1 HPV type (6/11/16/18) in this sub-cohort (N=384) varied by anatomic site, with 6.3%, 18.9%, and 0.0% seroconverting following anal, genital, and oral HPV infection, respectively. Regardless of anatomic site, seroconversion was highest for HPV 6 (19.3%). Overall, seroconversion was highest following anal HPV 6 infection (69.2%). HPV persistence was the only factor found to influence seroconversion.

Conclusions

Low seroconversion rates following HPV infection leave men susceptible to recurrent infections that can progress to HPV-related cancers. This emphasizes the need for HPV vaccination in men to ensure immune protection against new HPV infections and subsequent disease.

A longitudinal study of human papillomavirus 16 L1, e6, and e7 seropositivity and oral human papillomavirus 16 infection

BACKGROUND

Individuals with human papillomavirus (HPV) infections can develop IgG antibodies to HPV proteins including the L1 capsid and E6 and E7 oncoproteins. Evidence on whether L1 antibodies reduce the risk of cervical HPV infection is mixed, but this has not been explored for oral HPV infections. Antibodies to HPV16's E6 oncoprotein have been detected in some oropharyngeal cancer cases years before cancer diagnosis, but it is unknown if these antibodies are associated with oral HPV16 DNA.

METHODS

Enzyme-linked immunosorbent assays tested for serum antibodies to HPV16's L1 capsid in 463 HIV-infected and 293 HIV-uninfected adults, and for antibodies to recombinantly expressed E6 and E7 oncoproteins to HPV16 in 195 HIV-infected and 69 HIV-uninfected cancer-free participants at baseline. Oral rinse samples were collected semiannually for up to 3 years and tested for HPV DNA using PGMY 09/11 primers. Adjusted Poisson, logistic, and Wei-Lin-Weissfeld regression models were used.

RESULTS

Human papillomavirus 16 L1 seroreactivity did not reduce the subsequent risk of incident oral HPV16 infection in unadjusted (hazard ratio, 1.4; 95% confidence interval, 0.59-3.3) or adjusted (adjusted hazard ratio = 1.1; 95% confidence interval, 0.41-3.0) analysis. Antibodies to HPV16 E6 and E7 oncoproteins were detected in 7.6% and 3.4% of participants, respectively, but they were not associated with baseline oral HPV16 DNA prevalence or oral HPV16 persistence (each P > 0.40).

CONCLUSIONS

Naturally acquired HPV16 L1 antibodies did not reduce the risk of subsequent oral HPV16 infection. Human papillomavirus 16 E6 and E7 seropositivity was not a marker for oral HPV16 infection in this population without HPV-related cancer.