Determinants of seropositivity among HPV-16/18 DNA positive young women

Immune response following a two-dose schedule of bivalent HPV vaccination among girls and boys

Background

This longitudinal cohort study describes the kinetics in antibody levels after two doses of the bivalent human papillomavirus (HPV) vaccine in girls (birth cohort 2001) vaccinated in the routine Dutch vaccination program at 12 years of age, up to 7.5 years post-vaccination. Also, the antibody response one month post-vaccination of the first cohort of boys (birth cohort 2012, vaccinated at 10 years of age) eligible for HPV vaccination in the Netherlands is presented.

Method

Blood samples and questionnaire data were collected of girls and boys. HPV type-specific antibody concentrations (LU/mL) against HPV16/18/31/33/45/52/58 were assessed using a validated virus-like particle (VLP) multiplex immunoassay. For girls, antibody decays over time were modelled using the modified power-law decay model and the exponential decay model.

Results

The Geometric Mean Concentrations (GMCs) remained higher for HPV16/18 than for HPV types 31, 33, 45, 52, and 58 among girls up to 7.5 years post-vaccination. The antibody levels of HPV16 and HPV18 reached plateau values of 482 and 159 LU/mL, respectively. Mathematical modelling showed that the half-life values of HPV16/18 were 2.4- to 4.5-fold higher compared with the half-life values of the other HPV types. Among boys (aged 10 years), the GMC for HPV16 was significantly higher than among girls one month post-vaccination (aged 12 years).

Conclusion

The GMCs of all HPV types declined over time, although the GMCs of HPV16/18 remained relatively high up to 7.5 years post-vaccination. The GMCs for HPV16/18 among boys were at least equally high as the GMCs among girls at one month post-vaccination. Further follow-up of the cohort of boys is needed to gain knowledge on long-term immune responses of young boys following bivalent HPV vaccination.

Unraveling Immunological Dynamics: HPV Infection in Women-Insights from Pregnancy

During pregnancy, hormonal and immune adaptations are vital for supporting the genetically distinct fetus during elevated infection risks. The global prevalence of HPV necessitates its consideration during pregnancy. Despite a seemingly mild immune response, historical gestational viral infections underscore its significance. Acknowledging the established HPV infection risks during pregnancy, our review explores the unfolding immunological changes in pregnant women with HPV. Our analysis aims to uncover strategies for safely modulating the immune system, mitigating adverse pregnancy consequences, and enhancing maternal and child health. This comprehensive narrative review delves into the existing knowledge and studies on this topic.

Human papillomavirus seroprevalence and seroconversion following baseline detection of nine human papillomavirus types in young women

Background

Estimates of the humoral immune response to incident human papillomavirus (HPV) infections are limited.

Methods

In this post hoc analysis of 3875 women aged 16–23 years from a 4-valent HPV vaccine trial (NCT00092482), HPV seroprevalence on day 1 was measured with a 9-valent HPV (HPV 6/11/16/18/31/33/45/52/58) competitive Luminex immunoassay and compared with cervical/external genital HPV detection by polymerase chain reaction. In the control group, among women who were HPV DNA‒negative on day 1, seroconversion following initial HPV detection was estimated using Kaplan-Meier methods.

Results

Type-specific HPV seropositivity among women with no day 1 cervical/external genital HPV detection was 0.6%–3.6%. Women with any 9-valent HPV (9vHPV) cervical/external genital detection (796/3875; 20.5%) had concordant seropositivity ranging from 13.4% (HPV 45) to 38.5% (HPV 6). Among women in the control group who were negative for all HPV types on day 1, seroconversion by month 30 after initial detection ranged from 29% (HPV 45) to 75% (HPV 16).

Conclusions

Humoral immune response to HPV is variable and dynamic, depending on type-specific exposure. This longitudinal analysis provides insight into the relationship between incident infection and seropositivity.

ClinicalTrials.gov; NCT00092482 https://clinicaltrials.gov/ct2/show/NCT00092482.

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Research on humoral immune responses to HPV infection are limited.

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HPV-related serologic responses were analyzed in women aged 16–23 years.

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Type-specific HPV seropositivity was low in women without initial HPV DNA detection.

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Concordant seropositivity in women with any 9vHPV DNA detection ranged from 13% to 40%.

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Seroconversion to the same genotype within 30 months of an infection was common.

Naturally acquired HPV antibodies against subsequent homotypic infection: A large-scale prospective cohort study

Background

Although recent studies have suggested that naturally acquired Human papillomavirus (HPV) antibodies are partly protective against subsequent homotypic infection, the extent of protection remains indecisive. Here, we evaluate the protective effect of neutralizing and IgG antibodies simultaneously.

Methods

In a cohort of 3634 women aged 18-45 years from the control arm of a phase III trial of the HPV-16/18 bivalent vaccine, participants were tested for neutralizing antibodies by pseudovirion-based neutralization assay (PBNA) and IgG antibodies by enzyme-linked immunosorbent assay (ELISA) at baseline. HPV-16/18 incident and persistent infections were identified using cervical specimens periodically collected during the 5·5 years of follow-up. The protective effects of HPV-16/18 neutralizing and IgG antibodies against homotypic infection were assessed using a Cox proportional hazard model.

Findings

For the persistent infection (PI) endpoints of HPV-16/18 lasting for over 6/12 months, a prevalence of type-specific neutralizing antibodies was highly protective (6-month PI: hazard ratio (HR) = 0·16, 95% confidence interval (CI): 0·04, 0·65; 12-month PI: HR = 0·23, 95% CI: 0·06, 0·94), whereas a prevalence of IgG antibodies was associated with minor and non-significant protection (6-month PI: HR = 0·66, 95% CI: 0·40, 1·09; 12-month PI: HR = 0·66, 95% CI: 0·36, 1·20). After increasing the cut-off value to the median IgG level, the risk of 6-month PI was significantly lower in seropositive vs seronegative women (HR = 0·38, 95% CI: 0·18, 0·83).

Interpretation

Naturally acquired antibodies are associated with a substantially reduced risk of subsequent homotypic infection.

Funding

NSFC; The Fujian Province Health Education Joint Research Project; Xiamen Science and Technology Major Project; CIFMS; and Xiamen Innovax.

Predictors of Human Papillomavirus Seropositivity in Appalachian Women Aged 18 to 26 Years

BACKGROUND

Key informants of the Appalachian community questioned whether their unique environmental stressors would alter their immune response to human papillomavirus (HPV) infections. The primary aim of this study is to determine predictors of HPV seroprevalence to at least 1 of the 4 vaccine-related HPV types before vaccination using a psychoneuroimmunologic model in Appalachian women.

METHOD

Women aged 18 to 26 years (n = 185) who had not received HPV vaccination provided cervical HPV DNA and blood samples. Human papillomavirus DNA was identified through Hybrid Capture 2 assay and then genotyped for HPV types 6, 11, 16, and 18 by Roche Linear Array. Competitive Luminex Immunoassay measured the type-specific antibodies to HPV types 6, 11, 16, and 18 in milli-Merck units per milliliter. Nine psychoneuroimmunology scales measuring attributes of stress were self-completed.

RESULTS

Human papillomavirus DNA was detected in 50% (92/183) of participants, with only 14% (26/183) positive for HPV-6/11/16/18 DNA. Seropositivity for at least one anti-HPV-6/11/16 or 18, on the other hand, was present in 35% (64/183) of women, with only 10% (19/183) concomitantly infected and seropositive for the vaccine-related types. The Perceived Stress Scale was not a strong predictor of HPV seropositivity.

CONCLUSIONS

Both HPV infection and vaccine-related HPV type seropositivity is common among Appalachian women aged 18 to 26 years. The anticipated effect of environmental stressors on HPV seropositivity was not seen when multiple predictors were considered.

Sexual behavior and infection with cervical human papillomavirus types 16 and 18

Objective

This study assessed whether sexual behavior, including engaging in early sexual intercourse and having had multiple sexual partners, can predict the risk of infection with cervical human papillomavirus (HPV) types 16 and 18.

Methods

Records were reviewed of women who underwent cervical cancer screening and were found to be infected with high-risk HPV. The genotypes of high-risk HPV were categorized as HPV 16, HPV 18, and other than 16 or 18. Early sexual intercourse was defined as first sexual intercourse at the age of 19 years or younger. Multiple sexual partners was defined as having more than three lifetime sexual partners. Associations between sexual behavior and HPV 16/18 infection were presented as odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Of the 349 women included in the study, 72 (20.6%) and 30 (8.6%) were infected by HPV 16 and 18, respectively. Eighty-two women (26.0%) reported having engaged in early sexual intercourse, and 33 (10.4%) reported having had multiple sexual partners. After adjustment for age, parity, and smoking habits, we found that women who had engaged in early sexual intercourse tended to have a higher risk of HPV 16 (OR 1.74; 95% CI 0.93-3.29), and those who had had multiple sexual partners were found to be at a significantly higher risk for HPV 18 (OR 4.58; 95% CI 1.44-14.58).

Conclusion

Sexual behavior was associated with an increased risk of HPV 16/18 infection. Engaging in early sexual intercourse increased the risk of HPV 16 infection, and having had multiple sexual partners increased that of HPV 18.

Risk of newly detected infections and cervical abnormalities in adult women seropositive or seronegative for naturally acquired HPV-16/18 antibodies

BACKGROUND

Infections with human papillomavirus (HPV) types 16 and 18 account for ~70% of invasive cervical cancers but the degree of protection from naturally acquired anti-HPV antibodies is uncertain. We examined the risk of HPV infections as defined by HPV DNA detection and cervical abnormalities among women >25 years in the Human Papilloma VIrus Vaccine Immunogenicity ANd Efficacy trial's (VIVIANE, NCT00294047) control arm.

METHODS

Serum anti-HPV-16/18 antibodies were determined at baseline and every 12 months in baseline DNA-negative women (N = 2687 for HPV-16 and 2705 for HPV-18) by enzyme-linked immunosorbent assay (ELISA) from blood samples. HPV infections were identified by polymerase chain reaction (PCR) every 6-months, and cervical abnormalities were confirmed by cytology every 12 months. Data were collected over a 7-year period. The association between the risk of type-specific infection and cervical abnormalities and serostatus was assessed using Cox proportional hazard models.

RESULTS

Risk of newly detected HPV-16-associated 6-month persistent infections (PI) (hazard ratio [HR] = 0.56 [95%CI:0.32; 0.99]) and atypical squamous cells of undetermined significance (ASC-US+) (HR = 0.28 [0.12; 0.67]) were significantly lower in baseline seropositive vs baseline seronegative women. HPV-16-associated incident infections (HR = 0.81 [0.56; 1.16]) and 12-month PI (HR = 0.53 [0.24; 1.16]) showed the same trend. A similar trend of lower risk was observed in HPV-18-seropositive vs -seronegative women (HR = 0.95 [0.59; 1.51] for IIs, HR = 0.43 [0.16; 1.13] for 6-month PIs, HR = 0.31 [0.07; 1.36] for 12-month PIs, and HR = 0.61 [0.23; 1.61] for ASC-US+).

CONCLUSIONS

Naturally acquired anti-HPV-16 antibodies were associated with a decreased risk of subsequent infection and cervical abnormalities in women >25 years. This possible protection was lower than that previously reported in 15- to 25-year-old women.

Seroprevalence of HPV 6, 11, 16 and 18 and correlates of exposure in unvaccinated women aged 16-64 years in Puerto Rico

Background

To understand risk factors for HPV exposure in Puerto Rican women, we evaluated HPV 6, 11, 16, and 18 serology in women aged living in the San Juan metropolitan area.

Methods

As part of a cross-sectional study, a population-based sample of 524 HPV unvaccinated Hispanic women ages 16–64 years completed face-to-face and computer assisted interviews and provided blood and self-collected anal and cervical specimens. Serology used multiplex virus-like particle based-IgG ELISA and HPV DNA was detected with L1-consensus PCR.

Results

32% and 47% were seropositive to HPV types included in the bivalent (16/18) and quadrivalent (6/11/16/18) vaccines, respectively. Type-specific seroprevalence was HPV6 − 29%, HPV11 − 18%, HPV16 − 23%, and HPV18 − 17%; seroprevalence was high in the youngest age-group (16–19: 26–37%). HPV seropositivity was associated with having ≥ 3 lifetime sexual partners (OR=2.5, 95% CI=1.7–3.9) and detection of anogenital HPV DNA (OR=1.8, 95% CI=1.2–2.6).

Conclusions

The high cumulative exposure of HPV vaccine types 6/11/16/18 in this Hispanic population was influenced by factors related to HPV exposure through sexual behavior. High seroprevalence in the youngest age-group indicates early age of exposure to HPV in Puerto Rico, highlighting the need for HPV vaccination starting prior to age 16.

Smoking and subsequent human papillomavirus infection: a mediation analysis

PURPOSE

Smoking is an established risk factor for a human papillomavirus (HPV) infection advancing to cervical precancer and cancer, but its role earlier in the natural history is less clear. Smoking is inversely associated with possessing HPV antibodies from a past infection suggesting that smoking may influence acquiring subsequent infections.

METHODS

In a cohort of 1976 U.S. women, we evaluate whether reduced antibodies to HPV-16 is a mechanism for smoking's role on acquiring a subsequent HPV-16 infection, through the analytic technique of causal mediation analysis. We posit a causal model and estimate two counterfactually defined effects: a smoking impaired antibody-mediated indirect effect and a nonmediated direct effect representing all other potential mechanisms of smoking.

RESULTS

Compared to never smokers, current smokers had increased odds of HPV-16 infection by the antibody-mediated indirect effect (odds ratio [OR] = 1.29; 95% confidence interval [CI]: 1.11, 1.73); the estimated direct effect was very imprecise (OR = 0.57; 95% CI, 0.26-1.13). We observed a stronger estimated indirect effect among women who smoked at least half a pack of cigarettes daily (OR = 1.61, 95% CI, 1.27-2.15) than among women who smoked less than that threshold (OR = 1.09; 95% CI, 0.94-1.44).

CONCLUSIONS

This is the first study to directly test the mechanism underlying smoking as an HPV cofactor. The results support current smoking as a risk factor earlier in the natural history of HPV and are consistent with the hypothesis that smoking increases the risk of a subsequent infection by reducing immunity.

Determinants of High-Risk Human Papillomavirus Seroprevalence and DNA Prevalence in Mid-Adult Women

BACKGROUND

The epidemiology of high-risk human papillomavirus (hrHPV) infections in mid-adult women is not well understood.

METHODS

We conducted a cross-sectional analysis of 379 women 30 to 50 years of age. Vaginal samples were tested for type-specific HPV DNA by polymerase chain reaction. Sera were tested for type-specific HPV antibodies by Luminex-based assay. Assays included 13 hrHPV types (16/18/31/33/35/39/45/51/52/56/58/59/68). Self-reported health and sexual history were ascertained. Risk factors for seropositivity and DNA positivity to hrHPV were assessed in separate Poisson regression models.

RESULTS

The mean (SD) age of participants was 38.7 (6.1) years, and the median lifetime number of male sex partners was 7. Approximately two-thirds (68.1%) were seropositive for any hrHPV, 15.0% were DNA positive, and 70.7% were seropositive or DNA positive. In multivariate analyses, women who were married/living with a partner were less likely to be seropositive than single/separated women (adjusted prevalence ratio [aPR], 0.86; 95% confidence interval [CI], 0.75-0.98). Compared with never hormonal contraceptive users, current (aPR, 1.53; 95% CI, 1.01-2.29) or former (aPR, 1.64; 95% CI, 1.10-2.45) users were more likely to be seropositive. Women with a lifetime number of sex partners of 12 or more were more likely to be seropositive compared with those with 0 to 4 partners (aPR, 1.29; 95% CI, 1.06-1.56). Similar associations were seen with DNA positivity. In addition, there was a positive association between current smoking and hrHPV DNA (aPR vs. never smokers, 2.51; 95% CI, 1.40-4.49).

CONCLUSIONS

Seventy-one percent of mid-adult women had evidence of current or prior hrHPV infection. Measures of probable increased exposure to HPV infection were associated with both seropositivity and DNA positivity to hrHPV, whereas current smoking was positively associated with hrHPV DNA only.

HPV Serum Antibodies as Predictors of Survival and Disease Progression in Patients with HPV-Positive Squamous Cell Carcinoma of the Oropharynx

PURPOSE

Oropharyngeal carcinoma positive for human papillomavirus type 16 (HPV16) has a significantly better prognosis than oropharyngeal carcinoma unrelated to HPV. Within HPV16-positive oropharyngeal carcinoma, biomarkers of prognosis are urgently needed to individualize care. We hypothesized that serum antibodies specific to HPV16, the major HPV type causing oropharyngeal carcinoma, have biologic relevance and are potential biomarkers for improved prognosis among patients with HPV16-positive oropharyngeal carcinoma.

EXPERIMENTAL DESIGN

IgG antibodies to the HPV16 antigens E1, E4-E7, L1, L2, and the N-terminal and C-terminal fragments of E2 (NE2, CE2) were quantified using a custom programmable enzyme-linked immunosorbent assay. Sera were obtained at diagnosis from 209 oropharyngeal carcinoma patients (96 HPV16-positive). The ratios of median fluorescent intensity (MFI) for each antigen to MFI for control GST protein were determined. Kaplan-Meier survival curves and Cox proportional hazards regression were used to determine survival differences between groups. ROC curves were used to determine the best combination of E antibodies to predict disease recurrence.

RESULTS

E1, NE2, and E6 antibody positivity were all strongly associated with improved overall and progression-free survival in the entire cohort and in patients with known HPV16-positive tumors (P < 0.05). For both overall and progression-free survival among HPV-positive patients, hazard ratios were 0.2 for NE2, 0.3 for E1, and 0.3 for E6 antibody positivity.

CONCLUSIONS

We identified three HPV16-specific antibodies that are associated with improved overall and progression-free survival in patients with HPV-related oropharyngeal carcinoma. These results suggest that differential serologic responses in patients may reflect differential biologic processes within the host and tumor and may have prognostic value.

HIV is an important risk factor for human papillomavirus types 16 and 18 seropositivity among sexually active men who have sex with men

OBJECTIVE

The aim of this study was to investigate whether HIV infection is a main risk factor for human papillomavirus (HPV)-16 and HPV-18 seropositivity in men who have sex with men (MSM), and what other risk factors are associated with HPV-16 and HPV-18 seropositivity in this population.

METHODS

Men who have sex with men visiting a sexually transmitted infection (STI) clinic in Amsterdam in 2008 to 2009 answered questions concerning demographics and sexual behavior. Sera were tested for HPV antibodies to the major HPV capsid protein L1 by Luminex-based multiplex serology. As it is known that site of exposure is associated with seropositivity, this analysis was restricted to MSM who reported receptive anal sex during the preceding 6 months. Using multivariable logistic regression, we examined whether HIV was associated with HPV serostatus.

RESULTS

Included in the study were 415 HIV-negative and 205 HIV-positive MSM reporting receptive anal sex. Median age of the study population was 39 years (interquartile range, 31-44). Human papillomavirus seroprevalence differed significantly between HIV-negative and HIV-positive MSM: 31% versus 65% (P < 0.001) for HPV-16 and 28% versus 51% (P < 0.001) for HPV-18. After adjusting for important risk factors HPV-16 (adjusted odds ratio, 2.80; 95% confidence interval, 1.75-4.49) and HPV-18 (adjusted odds ratio, 1.78; 95% confidence interval, 1.11-2.85), seropositivity was significantly more common in HIV-positive than in HIV-negative MSM. We could not identify other consistent risk factors for HPV-16 and HPV-18 seropositivity.

CONCLUSIONS

HIV infection is an important risk factor for HPV-16 and HPV-18 seropositivity among MSM reporting receptive anal sex in the preceding 6 months.

The role of sexual behavior in head and neck cancer: implications for prevention and therapy

HPV-positive oropharyngeal squamous cell carcinoma (HPV-OSCC) is associated with oral sexual behaviors. The sharp rise in incidence of HPV-OSCC in the USA has been attributed to changes in sexual norms over the past five decades, with lower age at sexual debut and higher numbers of sexual partners per individual. In addition, variations in HPV-OSCC prevalence by race, age cohort and gender may be attributable to differences in oral sexual behaviors among these groups. Oral HPV infection is the putative precursor to HPV-OSCC. Risk factors for oral HPV incidence, prevalence, clearance and persistence are crucial to understanding how, and in whom, oral HPV infection progresses to malignancy. Future investigation should focus on elucidating the natural history of oral HPV infection persistence and malignant transformation, developing effective screening tools and exploring opportunities for prevention such as vaccination and public health education.

Human papillomavirus 16/18 seroprevalence in unvaccinated women over 30 years with normal cytology and with high grade cervical abnormalities in Australia: results from an observational study

Background

Australia commenced human papillomavirus (HPV) vaccination in 2007, with a two-year catch-up to the age of 26; catch-up cohorts are thus now entering their thirties. Plans for monitoring vaccine impact involve pre- and post-vaccination assessment of cervical HPV DNA in the general population and in high grade abnormalities. Although HPV serology is less sensitive than DNA genotyping, it assesses lifetime exposure and may be easier to measure in the general population. However, benchmark pre-vaccination seroprevalence of vaccine-included types in unvaccinated women with high grade abnormalities has not previously been reported.

Methods

We assessed seroprevalence for HPV16/18 from a population-based sample of 3,729 women with normal cytology and 971 women with confirmed high grade abnormalities (CIN2/3), aged 30–64 years, unvaccinated, and recruited in New South Wales in 2006–2010. We examined the variation in HPV16/18 seropositivity by age and in relation to a range of reproductive and behavioural characteristics in the subgroup of normal cytology women with no recent history of high grade cervical disease.

Results

The HPV 16, 18 and combined seroprevalence was 19%, 7% and 24% among women with normal cytology, and 39%, 13% and 44% among women with CIN2/3, respectively. For both groups, HPV16/18 seroprevalence was highest at age 30–39 years and decreased with age. In multivariable analysis for women with normal cytology, HPV16 and HPV18 seropositivity were each associated with the number of lifetime sexual partners (p-trend <0.001 and 0.052, respectively) and for HPV16 this was also associated with age (p-trend <0.001) and prior diagnosis of Chlamydia (adjusted OR 1.89, 95% CI 1.27-2.80).

Conclusions

The findings of this study inform pre-vaccination estimates of HPV seropositivity in women with normal cytology and women with high grade abnormalities. Almost a quarter of unvaccinated women aged over 30 years with normal cytology, and more than 40% of those with CIN2/3, had seroconverted to HPV 16 or 18. These findings provide a potential additional benchmark for assessing the effects of HPV vaccination.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0676-z) contains supplementary material, which is available to authorized users.

Determinants of baseline seroreactivity to human papillomavirus type 16 in the Ludwig-McGill cohort study

BACKGROUND

Immunity plays an important role in controlling human papillomavirus (HPV) infection and associated lesions. Unlike infections caused by other viruses, natural HPV infection does not always result in a protective antibody response. Therefore, HPV antibodies are also considered markers of cumulative exposure. The aim of this study was to identify determinants of HPV16 seroreactivity at enrollment among women from the Ludwig-McGill cohort, a natural history study of HPV infection and risk of cervical neoplasia.

METHODS

HPV16 serology was assessed by ELISA for L1 and L2 capsid antigens, while HPV typing and viral load measurements were performed by PCR-based methods. The associations were analyzed by unconditional logistic regression.

RESULTS

Of 2049 subjects, 425 (20.7%) were strongly seropositive for HPV16. In multivariate analysis, seroreactivity was positively correlated with age, lifetime number of sexual partners, frequency of sex, and HPV16 viral load, and negatively associated with duration of smoking.

CONCLUSIONS

HPV16 seroreactivity is determined by factors that reflect viral exposure.

Risk of newly detected infections and cervical abnormalities in women seropositive for naturally acquired human papillomavirus type 16/18 antibodies: analysis of the control arm of PATRICIA

BACKGROUND

We examined risk of newly detected human papillomavirus (HPV) infection and cervical abnormalities in relation to HPV type 16/18 antibody levels at enrollment in PATRICIA (Papilloma Trial Against Cancer in Young Adults; NCT00122681).

METHODS

Using Poisson regression, we compared risk of newly detected infection and cervical abnormalities associated with HPV-16/18 between seronegative vs seropositive women (15-25 years) in the control arm (DNA negative at baseline for the corresponding HPV type [HPV-16: n = 8193; HPV-18: n = 8463]).

RESULTS

High titers of naturally acquired HPV-16 antibodies and/or linear trend for increasing antibody levels were significantly associated with lower risk of incident and persistent infection, atypical squamous cells of undetermined significance or greater (ASCUS+), and cervical intraepithelial neoplasia grades 1/2 or greater (CIN1+, CIN2+). For HPV-18, although seropositivity was associated with lower risk of ASCUS+ and CIN1+, no association between naturally acquired antibodies and infection was demonstrated. Naturally acquired HPV-16 antibody levels of 371 (95% confidence interval [CI], 242-794), 204 (95% CI, 129-480), and 480 (95% CI, 250-5756) EU/mL were associated with 90% reduction of incident infection, 6-month persistent infection, and ASCUS+, respectively.

CONCLUSIONS

Naturally acquired antibodies to HPV-16, and to a lesser extent HPV-18, are associated with some reduced risk of subsequent infection and cervical abnormalities associated with the same HPV type.

Cross-sectional study of HPV-16 infection in a population-based subsample of Hispanic adults

OBJECTIVE

This study aimed to estimate the prevalence and correlates of seropositivity to human papillomavirus (HPV)-16 in a subsample of adults who participated in the parent study Epidemiology of Hepatitis C in the adult population of Puerto Rico (PR).

SETTING

The parent study was a population-based household survey aimed to estimate the seroprevalence of hepatitis C and other viral infections (hepatitis A, hepatitis B, HIV, and herpes simplex type 2) in PR (n=1654) between 2005 and 2008.

PARTICIPANTS

A subsample of the last 450 consecutive adults aged 21-64 years, recruited between February 2007 and January 2008, who participated in the parent study and agreed to participate in HPV testing.

PRIMARY AND SECONDARY OUTCOME MEASURES

The samples were tested by ELISA for HPV-16 viral-like particle-specific immunoglobulin G. Information on sociodemographic, health, and lifestyle characteristics was collected. Logistic regression modelling was used to estimate the prevalence odds ratio (POR) to assess factors associated to HPV-16 seropositivity.

RESULTS

Prevalence of seropositivity to HPV-16 was 11.3%. Seroprevalence was higher in women (15.8%) than men (5.6%; p=0.001). After adjusting for age and sex, ever smokers (POR 2.06, 95% CI 1.08 to 3.92) and participants with at least five lifetime sexual partners (POR 2.91, 95% CI 1.24 to 6.81) were more likely to be HPV-16 seropositive.

CONCLUSIONS

HPV-16 seropositivity is similar to that reported in the USA (10.4%) for NHANES 2003-2004 participants, although different assays were used in these studies. While future studies should evaluate HPV seroprevalence using a larger population-based sample, our results highlight the need to further understand the burden of HPV infection and HPV-related malignancies in PR, population with a low vaccine uptake.

A study of cervical intraepithelial neoplasia in pregnancy

OBJECTIVE

To find the incidence of human papillomavirus (HPV) infection and cervical intraepithelial neoplasia (CIN) in pregnant women and compare Pap smear with the HPV DNA test in detecting HPV infection.

MATERIALS AND METHODS

Hundred antenatal women, irrespective of gestational age, were enrolled as subjects in this prospective pilot study for blood investigations, wet mount examination of cervical discharge, Pap smear, and high-risk HPV DNA detection of cervical scrape by PCR. Women showing abnormality in Pap smear and/or those who were high-risk HPV DNA positive were subjected to colposcopy.

RESULTS

The incidence of HPV-positive pregnant women was 18 %. Koilocytosis on Pap smear was observed in six women. Three high-risk HPV DNA-positive women showed changes consistent with CIN 1 on colposcopy.

CONCLUSIONS

The HPV DNA test is the most sensitive and reliable in detecting HPV infection as compared to Pap smear, but considering the cost of PCR, Pap smear screening of all antenatal women was recommended.

Prevalence and risk factors for neutralizing antibodies to human papillomavirus types 16 and 18 in HIV-positive men who have sex with men

OBJECTIVE

Human papillomavirus (HPV) vaccination is routinely recommended in HIV-positive men who have sex with men (MSM) aged ≤ 26 years. Levels of previous HPV exposure in older HIV-positive MSM are assumed to be too high to warrant routine HPV vaccination. However, little is known about the prevalence of and risk factors for neutralizing antibody seropositivity to HPV-16 or HPV-18, a key measure of previous exposure to these types.

METHODS

Cross-sectional analysis of baseline visit for 296 HIV-positive MSM participating in a prospective cohort study of anal squamous intraepithelial lesions at a university-based research clinic. Participants completed a questionnaire detailing behaviors and medical history. Phlebotomy, anal cytology, HPV DNA testing with quantitation, and high-resolution anoscopy with biopsy were performed. A pseudovirion-based neutralizing antibody assay was used to measure HPV-16 and HPV-18 neutralizing antibodies.

RESULTS

One hundred thirty-two of 296 (45%) men were HPV-16 seropositive and 141 of 296 (48%) were HPV-18 seropositive. One hundred seventy-five of 296 (59%) of the men were positive for HPV-16 antibodies or DNA and 167 of 296 (56%) were positive for HPV-18 antibodies or DNA. In multivariable analysis, HPV-16 seropositivity did not correlate with age, years of HIV positivity, CD4 level, or HIV viral load. Significant risk factors included HPV-16 DNA positivity with higher DNA levels (ptrend < 0.001) and higher number of receptive sexual partners in the last year (ptrend = 0.012).

CONCLUSIONS

A high proportion of HIV-positive MSM aged >26 years are DNA negative and seronegative to HPV-16 and HPV-18 even when using a sensitive pseudovirion-based neutralizing antibody assay. Prospective studies are needed to determine the clinical- and cost-effectiveness of HPV vaccination in HIV-positive MSM aged >26 years.

Natural immune responses against eight oncogenic human papillomaviruses in the ASCUS-LSIL Triage Study

Only a subset of women with human papillomavirus (HPV) infections will become seropositive, and the factors influencing seroconversion are not well understood. We used a multiplex serology assay in women with mildly abnormal cytology results to examine seroreactivity to oncogenic HPV genotypes. An unbiased subset of women in the atypical squamous cell of undetermined significance /low-grade squamous intraepithelial lesion Triage Study provided blood samples at trial enrollment for serological testing. A Luminex assay based on glutathione s-transferase-L1 fusion proteins as antigens was used to test seroreactivity against eight carcinogenic HPV genotypes (16, 18, 31, 33, 35, 45, 52 and 58). We analyzed the relationship between seroprevalence in women free of precancer (N = 2,464) and HPV DNA status, age, sexual behavior and other HPV-related risk factors. The overall seroprevalence was 24.5% for HPV16 L1 and ∼20% for 18L1 and 31L1. Among women free of precancer, seroprevalence peaked in women less than 29 years and decreased with age. Type-specific seroprevalence was associated with baseline DNA detection for HPV16 (OR = 1.36, 95%CI: 1.04-1.79) and HPV18 (OR = 2.31, 95%CI: 1.61-3.32), as well as for HPV52 and HPV58. Correlates of sexual exposure were associated with increased seroprevalence across most genotypes. Women who were current or former smokers were less likely to be seropositive for all eight of the tested oncogenic genotypes. The multiplex assay showed associations between seroprevalence and known risk factors for HPV infection across nearly all tested HPV genotypes but associations between DNA- and serostatus were weak, suggesting possible misclassification of the participants' HPV serostatus.

Association of HPV types 6, 11, 16, and 18 DNA detection and serological response in unvaccinated adolescent women

Antibodies directed against the human papillomavirus (HPV) L1 protein are detected in approximately 70% of individuals with HPV infections. The factors associated with a serological response are not characterized. It is hypothesized that the HPV viral load, duration of detection, or both would be associated with seropositivity in adolescent women. Adolescent women (n = 117), ages 15-17 at enrolment were followed for a mean of 6.2 years. Quarterly vaginal swabs (mean 22 per participant) were used to identify HPV 6, 11, 16, or 18 DNA (Roche PCR/Linear Array). Type-specific HPV infection was defined as ≥2 positive assays. To approximate viral load, Roche PCR/Linear Array test strips were scored visually based on the strength of signal relative to beta-globin controls. Sera collected near the end of study were tested by cLIA. Regression models were fit to assess associations between strength of signal (as represented by mean and cumulative strength of signal), duration of HPV detection, seropositivity, and serotiter. Detection of HPV DNA was associated with seropositivity for four types combined and for types 6, 16, and 18. Overall, 70.1% of DNA positive episodes were associated with type-specific seropositivity. The cumulative HPV DNA signal strength during periods of HPV detection for types 6, 11, 16, and 18 combined was associated with seropositivity (OR = 1.21, 95% CI 1.02-1.44 P = 0.026). No other HPV DNA predictors were found to be associated with seropositivity or serotiter.

Natural immune responses against eight oncogenic human papillomaviruses in the ASCUS-LSIL Triage Study

Only a subset of women with human papillomavirus (HPV) infections will become seropositive, and the factors influencing seroconversion are not well understood. We used a multiplex serology assay in women with mildly abnormal cytology results to examine seroreactivity to oncogenic HPV genotypes. An unbiased subset of women in the atypical squamous cell of undetermined significance /low-grade squamous intraepithelial lesion Triage Study provided blood samples at trial enrollment for serological testing. A Luminex assay based on glutathione s-transferase-L1 fusion proteins as antigens was used to test seroreactivity against eight carcinogenic HPV genotypes (16, 18, 31, 33, 35, 45, 52 and 58). We analyzed the relationship between seroprevalence in women free of precancer (N = 2,464) and HPV DNA status, age, sexual behavior and other HPV-related risk factors. The overall seroprevalence was 24.5% for HPV16 L1 and ∼20% for 18L1 and 31L1. Among women free of precancer, seroprevalence peaked in women less than 29 years and decreased with age. Type-specific seroprevalence was associated with baseline DNA detection for HPV16 (OR = 1.36, 95%CI: 1.04-1.79) and HPV18 (OR = 2.31, 95%CI: 1.61-3.32), as well as for HPV52 and HPV58. Correlates of sexual exposure were associated with increased seroprevalence across most genotypes. Women who were current or former smokers were less likely to be seropositive for all eight of the tested oncogenic genotypes. The multiplex assay showed associations between seroprevalence and known risk factors for HPV infection across nearly all tested HPV genotypes but associations between DNA- and serostatus were weak, suggesting possible misclassification of the participants' HPV serostatus.

Chemically modified bovine beta-lactoglobulin inhibits human papillomavirus infection

Previous studies have shown that 3-hydroxyphthalic anhydride-modified bovine beta-lactoglobulin is a promising anti-HIV microbicide candidate. Here we found that this chemically modified protein, designated JB01, exhibited highly potent antiviral activity against infection by human papillomaviruses (HPV), including HPV6, HPV16 and HPV18. Its anti-HPV activity was correlated with the percentage of modified lysine and arginine residues in JB01. This modified milk protein had no cytotoxicity at the concentration of 1 mg/ml, and it is highly stable at room temperature and 37 °C for at least 12 weeks. These results suggest that JB01 has good potential to be developed as an effective, safe and inexpensive antiviral agent for treatment and prevention of HPV infection.

A review of methods for detect human Papillomavirus infection

Human Papillomavirus (HPV) is the most common sexually transmitted virus. Worldwide, the most common high-risk (HR)-HPV are -16/18, and approximately 70% of cervical cancers (CC) are due to infection by these genotypes. Persistent infection by HR-HPV is a necessary but not sufficient cause of this cancer, which develops over a long period through precursor lesions, which can be detected by cytological screening. Although this screening has decreased the incidence of CC, HPV-related cervical disease, including premalignant and malignant lesions, continues to be a major burden on health-care systems. Although not completely elucidated, the HPV-driven molecular mechanisms underlying the development of cervical lesions have provided a number of potential biomarkers for both diagnostic and prognostic use in the clinical management of women with HPV-related cervical disease, and these biomarkers can also be used to increase the positive predictive value of current screening methods. In addition, they can provide insights into the biology of HPV-induced cancer and thus lead to the development of nonsurgical therapies. Considering the importance of detecting HPV and related biomarkers, a variety of methods are being developed for these purposes. This review summarizes current knowledge of detection methods for HPV, and related biomarkers that can be used to discriminate lesions with a high risk of progression to CC.

Next Generation Cancer Protection: The Bivalent HPV Vaccine for Females

Nearly a half a million women throughout the world develop cervical cancer every year Parkin and Bray ("Chapter 2. The burden of HPVrelated cancers," Vaccine, vol. 24, no. 3, pp. S11-S25, 2006); 80% of these women are in countries without a quality-assured cytology screening program. It is in this setting that Cervarix could reduce the incidence of cervical cancer to about 9.5/100,000 women. New evidence indicates that this might be able to be accomplished with a single dose of Cervarix, a great advantage to public health implementation programs Kreimer et al. ("Proof-of-principle evaluation of the efficacy of fewer than three doses of a bivalent HPV16/18 vaccine, The Journal of the National Cancer Institute, vol. 103, no. 19, pp. 1444-1451, 2011). In countries with screening programs, adenocarcinoma is the most difficult to detect and treat with later-stage presentation and higher mortality Smith et al. ("The rising incidence of adenocarcinoma relative to squamous cell carcinoma of the uterine cervix in the United States-a 24-year population-based study," Gynecologic Oncology, vol. 78, no. 2, pp. 97-105, 2000) and Gunnell et al. ("A longitudinal Swedish study on screening for squamous cell carcinoma and adenocarcinoma: evidence of effectiveness and overtreatment," Cancer Epidemiology Biomarkers and Prevention, vol. 16, no. 12, pp. 2641-2648, 2007). With additional cross-protection to HPV 31, 33, and 45 and protection against HPV 16 and 18 lasting at least 9.4 years, Cervarix may reduce adenocarcinomas in screened populations by more than 90%. This paper will detail the evidence about the efficacy, immunogenicity, and safety of Cervarix in the studied populations contrasting public health goals with individual health options.

Spinocellular carcinoma from warts in a HPV infection natural history lasting 49 years. Virus strategy or host choice? Implications for researches and therapeutic vaccines

There is a very strong evidence that progression (also to cancer) in variable percentages of cases infected by HPV, HBV, HCV, and HIV depends on host immune response. A large number of observations demonstrate that virus set up a postulated "active strategy" to modify host reactions or to avoid it. But in all those infections it also seems that antigen load (viral RNA or DNA), chronic activation of immune response and time elapsing from the primary infection play a pivotal role in determining clearing or persisting outcomes. My wife's HPV and cancer natural history, lasting 49 years, started at the age of 10 years with facial warts and progressed to CIN 2/3, cervical in situ carcinoma, perineal warts, perianal carcinoma, inguinal lymph nodes, and invasion of bones and muscular structures, until death is paradigmatic: a progressive immune failure was detected in her scaling up all those clinical features, ending in a massive apoptosis of her lymphocytes collected by leukapheresis and cultured with HPV antigens E6/E7, with the aim of obtaining antigen presenting cells and CD8+ specific T lymphocytes. From this experience, a concept of "host choice to reach a tolerance (mainly by a Tregs mediated anergy) or symbiotic-like state" arises, underlining all the affected host's immune-responses to virus persistence (and to consequent tumors). It might be then postulated as the hallmark of a long-term host/parasites co-evolution, and considered a "normal" reaction when the host faces overwhelming numbers of non-self cancer cells (high antigen loads) preceded by persistent virus infections (chronic activation). This happens in patients who do not clear HPV or other viruses soon enough after infection. These observations may lead to a better understanding of many phenomena that are actually difficult to explain or still are open questions. The auto-limiting host's immune-responses are likely to be aimed to avoid risks arising mainly in the protection of "self" (autoimmunity), to prolong its own survival (balance with the virus), to avoid the risk of producing uncontrolled cells (dangerous outcomes). Finally, the postulated negative implications for therapeutic vaccines in cervical cancer, as they really seem to not work till now might be ascribed just to the cited host immune-specific state itself, through an activation induced cell death, elicited by recall antigens (E6/E7 in the case of my wife). Also this latter hypothesis, as well as the previous ones may be of some value to better account for clinical behaviors and researches.

Oncogenic potential of Human Papillomavirus (HPV) and its relation with cervical cancer

Human Papillomavirus (HPV) is the most common cause of cervical cancer. Cervical cancer being the second most common cancer after lung cancer, affecting women of different age groups; has a prevalence of about 20% in young sexually active women. Among different types of HPV, HPV16 the major strain causing this cancer and is sexually transmitted had been unnoticed for decades. Keeping in mind the multiple risk factors related with cervical cancer such as early age sexual activities, teenage pregnancies, smoking, use of oral contraceptives, having multiple sex partners, hormone replacement therapies and various other unknown factors lead to the onset of the disease. Awareness for various diagnostic procedures such as Pap smears screening prove to be an effective way in eradicating the oncogenic potential of HPV.