Evaluation of a multiplex panel of immune-related markers in cervical secretions: a methodologic study

Although persistent carcinogenic human papillomavirus (HPV) infection is necessary for cervical carcinogenesis, the cofactors involved in HPV persistence and disease progression are poorly understood. Chronic cervical inflammation may increase risk, but few studies have measured immune markers (cytokines, chemokines and soluble receptors) in cervical secretions. We evaluated the performance of 74 multiplexed, bead-based immune markers in cervical secretions from three groups of women with biopsy evaluation of cervical intraepithelial neoplasia (CIN), (i) 25% detectability and >80% interclass correlation coefficients (ICCs) acceptable for epidemiologic studies. Within-batch coefficients of variation (CVs) of ≥25% indicated room for assay improvement. Secondarily, we explored associations between marker levels and CIN/HPV status adjusted for matching variables, assay batch, age and number of sexual partners. Sixty-two markers (84%) had >25% detectability and ICCs > 80%. Of those, 53 (85%) had CVs < 25%. Using these preliminary data, we found that HPV positivity was associated with increased eotaxin-1 [odds ratio (OR): 15.63, 95% confidence interval (CI): 1.26-200.00] and G-CSF (OR: 12.99, 95% CI: 1.10-142.86) among CIN-negative women. There was suggestive evidence that higher chemoattractant marker levels were associated with CIN2/3 (e.g., MIP-1delta, OR: 4.48, 95% CI: 0.87-23.04 versus Collapse

Key Words

• cervical intraepithelial neoplasia
• cervical secretions
• human papillomavirus
• immunology

Collapse

MESH Headings

• Adult
• Biomarkers/blood
• Disease Progression
• Female
• Follow-Up Studies
• Humans
• Luminescent Measurements
• Neoplasm Staging
• Papillomaviridae
• Papillomavirus Infections/complications
• Papillomavirus Infections/virology
• Prognosis
• Uterine Cervical Neoplasms/diagnosis
• Uterine Cervical Neoplasms/etiology
• Uterine Cervical Neoplasms/metabolism
• Young Adult
• Uterine Cervical Dysplasia/diagnosis
• Uterine Cervical Dysplasia/etiology
• Uterine Cervical Dysplasia/metabolism

Collapse

Grants

• Y99 CA999999 NCI NIH HHS
• Z99 CA999999 Intramural NIH HHS

Collapse

Comparison of antibody responses to human papillomavirus vaccination as measured by three assays

BACKGROUND

Different assays, including the competitive Luminex immunoassay (cLIA), secreted alkaline phosphatase neutralization assay (SEAP-NA), and virus-like particle-based ELISA, are commonly used to measure antibody responses after human papillomavirus (HPV) vaccination. Direct assay comparisons aid interpretation of immunogenicity data evaluated by different assays.

METHODS

We compared cLIA to SEAP-NA and ELISA among 51 HPV16/18-vaccinated women enrolled in the Costa Rica Vaccine Trial. We tested replicate serum samples collected at months 0, 1, and 12 by HPV16/18 cLIA, SEAP-NA, and ELISA. For a subset (N = 10), we further tested month 6, 24 and 36 samples. We calculated seroprevalence estimates and Spearman rank correlation coefficients comparing cLIA to SEAP-NA and ELISA.

RESULTS

After one vaccine dose, seroprevalence by SEAP-NA and ELISA was 100% (both HPV16 and HPV18), and by cLIA was 96% (95% CI 87-100%) for HPV16 and 71% (95% CI 56-83%) for HPV18. Seroprevalence was 100% by all assays after three doses. Correlation between assays was high after one vaccine dose [cLIA/SEAP-NA ρ = 0.91 (HPV16) and ρ = 0.86 (HPV18); cLIA/ELISA ρ = 0.84 (HPV16) and ρ = 0.74 (HPV18); all p < 0.001] and remained high through month 36. Ratios of mean antibody levels to seropositivity cutoffs at month 36 were lower for cLIA than for SEAP-NA or ELISA, particularly for HPV18 (HPV18 ratio for cLIA 1.9, SEAP-NA 3.5, ELISA 3.4).

CONCLUSION

Though correlation between cLIA and SEAP-NA/ELISA is high and stable after vaccination, the assays differ in scale and sensitivity, with notable differences after one vaccine dose and for HPV18. Our results demonstrate that comparisons of antibody responses to HPV vaccination measured by different assays are approximate, and must consider biological and technical differences between assays.

Comprehensive control of human papillomavirus infections and related diseases

Infection with human papillomavirus (HPV) is recognized as one of the major causes of infection-related cancer worldwide, as well as the causal factor in other diseases. Strong evidence for a causal etiology with HPV has been stated by the International Agency for Research on Cancer for cancers of the cervix uteri, penis, vulva, vagina, anus and oropharynx (including base of the tongue and tonsils). Of the estimated 12.7 million new cancers occurring in 2008 worldwide, 4.8% were attributable to HPV infection, with substantially higher incidence and mortality rates seen in developing versus developed countries. In recent years, we have gained tremendous knowledge about HPVs and their interactions with host cells, tissues and the immune system; have validated and implemented strategies for safe and efficacious prophylactic vaccination against HPV infections; have developed increasingly sensitive and specific molecular diagnostic tools for HPV detection for use in cervical cancer screening; and have substantially increased global awareness of HPV and its many associated diseases in women, men, and children. While these achievements exemplify the success of biomedical research in generating important public health interventions, they also generate new and daunting challenges: costs of HPV prevention and medical care, the implementation of what is technically possible, socio-political resistance to prevention opportunities, and the very wide ranges of national economic capabilities and health care systems. Gains and challenges faced in the quest for comprehensive control of HPV infection and HPV-related cancers and other disease are summarized in this review. The information presented may be viewed in terms of a reframed paradigm of prevention of cervical cancer and other HPV-related diseases that will include strategic combinations of at least four major components: 1) routine introduction of HPV vaccines to women in all countries, 2) extension and simplification of existing screening programs using HPV-based technology, 3) extension of adapted screening programs to developing populations, and 4) consideration of the broader spectrum of cancers and other diseases preventable by HPV vaccination in women, as well as in men. Despite the huge advances already achieved, there must be ongoing efforts including international advocacy to achieve widespread-optimally universal-implementation of HPV prevention strategies in both developed and developing countries. This article summarizes information from the chapters presented in a special ICO Monograph 'Comprehensive Control of HPV Infections and Related Diseases' Vaccine Volume 30, Supplement 5, 2012. Additional details on each subtopic and full information regarding the supporting literature references may be found in the original chapters.

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.

A comparison of cervical histopathology variability using whole slide digitized images versus glass slides: experience with a statewide registry

Whole slide imaging is increasingly used for primary and consultative diagnoses, teaching, telepathology, slide sharing, and archiving. We compared pathologist evaluations of glass slides and corresponding digitized images within the context of a statewide surveillance effort. Cervical specimens collected by the New Mexico HPV Pap Registry research program targeted cases diagnosed between 2006 and 2010. Two samples of 250 slides each were digitized with the ScanScope XT (Aperio, Vista, CA) microscope and reviewed with Aperio ImageScope reader. (1) A "random set" had a distribution of community diagnoses: 70% from cases of cervical intraepithelial neoplasia grade 2 or higher, 20% from cases of cervical intraepithelial neoplasia grade 1 and 10% from negative cases. (2) A "discrepant set" was represented by difficult cases where 2 study pathologists initially disagreed. Within the regular workflow of the New Mexico HPV Pap Registry, 3 pathologists read the slides 2 to 3 times each without knowledge of clinical history, previous readings or sampling scheme. Pathologists also read each corresponding image twice. For within- and between-reader comparisons we calculated unweighted κ statistics and asymmetry χ(2) tests. Across all comparisons, slides and images yielded similar results. For the random set, almost all within-reader and between-reader Kappa values ranged between 0.7 and 0.8 and 0.6 and 0.7, respectively. For the discrepant set, most within- and between-reader κ values were 0.4 to 0.6. As cervical intraepithelial neoplasia diagnostic terminology changes, pathologists may need to re-read histopathology slides to compare disease trends over time, eg, before/after introduction of human papillomavirus vaccination. Diagnosis of cervical intraepithelial neoplasia differed little between slides and corresponding digitized images.

No evidence for synergy between human papillomavirus genotypes for the risk of high-grade squamous intraepithelial lesions in a large population-based study

BACKGROUND

Multiple human papillomavirus (HPV) genotypes may be independently or synergistically associated with risk of high-grade squamous intraepithelial lesions (HSILs). We evaluated the risk of HSIL in women concomitantly infected with multiple HPV genotypes.

METHODS

A population-based stratified sample of 59 664 cervical cytology specimens from women residing in New Mexico were evaluated for cytologic abnormalities and HPV genotypes. We calculated the risk of HSIL in women infected with a single HPV genotype and the risk in those infected with multiple HPV genotypes.

RESULTS

The highest risk of HSIL was observed for HPV-16 (0.036), followed by HPV-33 (0.028), HPV-58 (0.024), and HPV-18 (0.022). For most types, we observed a greater risk of HSIL in women infected with multiple carcinogenic HPV types. In contrast, the risk of HSIL was similar in women infected with HPV-16 and other types, compared with women infected with HPV-16 only. We observed an increased but plateauing risk of HSIL in women infected with multiple types, compared with those infected with a single type, with risk ratios of 1.5 (95% confidence interval [CI], 1.2-1.8), 1.7 (95% CI, 1.3-2.4), and 1.4 (95% CI, 0.83-2.5) for women infected with 2, 3, and ≥4 genotypes, respectively.

CONCLUSIONS

In the largest population-based study of HPV genotypes and cytologic outcomes so far, we did not see more than additive effects of HPV types on the risk of HSIL in women infected with multiple types.

Plasma cytokine levels and human papillomavirus infection at the cervix in rural Nigerian women

INTRODUCTION

We conducted a study to test the hypothesis that systemic dysregulation of Th1/Th2 cytokine levels was associated with detection of carcinogenic or overall human papillomavirus (HPV) at the cervix among 964 women residing in a rural village in Nigeria.

METHODS

Levels in plasma were measured for 19 cytokines, including Th1-like cytokines IL-2, IL-12 (p40), TNF-a, IFN-g; Th2-like cytokines IL-4, IL-5, IL-6, IL-10, IL-13; innate/inflammation cytokines IL-1a, IL-1b, IL-8, eotaxin, MCP-1, MIP-1a, and IL-7; and cell development cytokines G-CSF, VEGF, and IL-17. Analysis was restricted to 5 cytokines, TNF-α (Th1), IL-8 (Th2), eotaxin and MCP-1 (innate/inflammation), and G-CSF (cell development), whose levels were detected in 80% or more of the samples measured as well as had a coefficient of variation of <30%.

RESULTS

Strong correlations were noted between levels of eotaxin and TNF-α (r=0.75), IL-8 and MCP-1 (r=0.60), eotaxin and G-CSF (r=0.44), and G-CSF and IFN-γ (r=0.43). Detection of carcinogenic or non-carcinogenic HPV DNA was unrelated to cytokine levels, except for levels of eotaxin and TNF-α, which were inversely correlated, albeit weakly, with detection of any carcinogenic HPV (P=0.048 and P=0.067, respectively). In analyses stratified by age group, levels of eotaxin were inversely correlated with detection of any HPV DNA (P=0.026) and carcinogenic HPV (P=0.042) in older, but not younger, women.

CONCLUSIONS

Our results do not support the hypothesis of association between systemic cytokine dysregulation and detection of HPV at the cervix in Nigerian women, but subgroup analyses raise questions about inverse associations between eotaxin and TNF-α in older women.

Prevalence of and risk factors for oral human papillomavirus among young women in Costa Rica

BACKGROUND

Little is known about the epidemiology of oral human papillomavirus (HPV) in Latin America.

METHODS

Women (N = 5838) aged 22-29 in the control and vaccine arms of an HPV-16/18 vaccine trial in Costa Rica had oral, cervical, and anal specimens collected. Samples were tested for alpha mucosal HPV types (SPF10/LiPA25 version 1); a subset of oral samples (n = 500) was tested for cutaneous HPV types in the genera alpha, beta, gamma, mu, and nu.

RESULTS

In the control arm (n = 2926), 1.9% of women had an oral alpha mucosal HPV detected, 1.3% had carcinogenic HPV, and 0.4% had HPV-16; similar patterns for non-16/18 HPV types were observed in the vaccine arm. Independent risk factors for any oral alpha mucosal HPV among women in the control arm included marital status (adjusted odds ratio [AOR], 3.2; 95% confidence interval [CI], 1.8-5.7 for single compared to married/living as married), number of sexual partners (AOR, 2.4; 95% CI, 1.0-6.1 for ≥4 partners compared to 0-1 partners), chronic sinusitis (AOR, 3.1; 95% CI, 1.5-6.7), and cervical HPV infection (AOR, 2.6; 95% CI, 1.4-4.6). Detection of beta HPV was common (18.6%) and not associated with sexual activity.

CONCLUSIONS

Unlike cutaneous HPV types, alpha mucosal HPV types were uncommon in the oral region and were predominately associated with sexual behavior. Clinical Trials Registration. NCT00128661.

Chromosomal gains measured in cytology samples from women with abnormal cervical cancer screening results

OBJECTIVE

Chromosomal gains at 3q26, 5p15 and 20q13 have been described in cervical precancer and cancer. We evaluated a novel fluorescence in situ hybridization (FISH) assay that detects gains at these three loci simultaneously as a possible biomarker for detecting cervical precancer.

METHODS

Chromosomal copy numbers at 3q26, 5p15, 20q13 and the centromere of chromosome7 (cen7) in liquid-based cytology specimens from 168 women enrolled in the Biopsy Study were determined by FISH. The number of cells with ≥ 3 or ≥ 4 signals for a genomic locus was enumerated and diagnostic test performance measures were calculated using receiver operating characteristic (ROC) analyses. Sensitivity and specificity values were determined for the detection of CIN2+ and/or HSIL.

RESULTS

The median number of cells with ≥ 3 signals increased with the severity of cervical lesion for each genomic locus (p-trend<0.02 for each locus). ROC analysis for the number of cells with ≥ 3 signals resulted in area under the curve values of 0.70 (95% CI: 0.54-0.86), 0.67 (0.52-0.83), 0.67 (0.51-0.83) and 0.78 (0.64-0.92) for 3q26, 5p15, 20q13 and cen7, respectively, for the detection of CIN2+ and/or HSIL. Positivity for gains at multiple loci resulted in only slightly better test performance measures than those for the individual probes for four distinct combinations of probes.

CONCLUSIONS

Chromosomal gains at 3q26, 5p15, 20q13 and cen7 are associated with severity of cervical lesions. Further studies are required to quantify risk stratification of FISH assays for cervical cancer screening.

Impact of human papillomavirus vaccination on cervical cytology screening, colposcopy, and treatment

The impact of human papillomavirus (HPV) vaccination on cervical screening, colposcopy, and treatment is incompletely understood. In 2004-2005, investigators in the Costa Rica Vaccine Trial randomized 7,466 women aged 18-25 years, 1:1, to receive HPV vaccination or hepatitis A vaccination. The worst-ever cytology diagnosis and the 4-year cumulative proportions of colposcopy referral and treatment by vaccination arm were compared for 2 cohorts. The total vaccinated cohort included 6,844 women who provided cervical samples. The naive cohort included 2,284 women with no evidence of previous HPV exposure. In the total vaccinated cohort, HPV-vaccinated women had a significant (P = 0.01) reduction in cytological abnormalities: 12.4% for high-grade lesions and 5.9% for minor lesions. Colposcopy referral was reduced by 7.9% (P = 0.03) and treatment by 11.3% (P = 0.24). Greater relative reductions in abnormal cytology (P < 0.001) were observed for HPV-vaccinated women in the naive cohort: 49.2% for high-grade lesions and 18.1% for minor lesions. Colposcopy referral and treatment were reduced by 21.3% (P = 0.01) and 45.6% (P = 0.08), respectively, in the naive cohort. The overall impact on health services will be modest in the first years after vaccine introduction among young adult women, even in regions with high coverage.

Evolution and taxonomic classification of alphapapillomavirus 7 complete genomes: HPV18, HPV39, HPV45, HPV59, HPV68 and HPV70

BACKGROUND

The species Alphapapillomavirus 7 (alpha-7) contains human papillomavirus genotypes that account for 15% of invasive cervical cancers and are disproportionately associated with adenocarcinoma of the cervix. Complete genome analyses enable identification and nomenclature of variant lineages and sublineages.

METHODS

The URR/E6 region was sequenced to screen for novel variants of HPV18, 39, 45, 59, 68, 70, 85 and 97 from 1147 cervical samples obtained from multiple geographic regions that had previously been shown to contain an alpha-7 HPV isolate. To study viral heterogeneity, the complete 8 kb genome of 128 isolates, including 109 sequenced for this analysis, were annotated and analyzed. Viral evolution was characterized by constructing phylogenic trees using maximum-likelihood and Bayesian algorithms. Global and pairwise alignments were used to calculate total and ORF/region nucleotide differences; lineages and sublineages were assigned using an alphanumeric system. The prototype genome was assigned to the A lineage or A1 sublineage.

RESULTS

The genomic diversity of alpha-7 HPV types ranged from 1.1% to 6.7% nucleotide sequence differences; the extent of genome-genome pairwise intratype heterogeneity was 1.1% for HPV39, 1.3% for HPV59, 1.5% for HPV45, 1.6% for HPV70, 2.1% for HPV18, and 6.7% for HPV68. ME180 (previously a subtype of HPV68) was designated as the representative genome for HPV68 sublineage C1. Each ORF/region differed in sequence diversity, from most variable to least variable: noncoding region 1 (NCR1) / noncoding region 2 (NCR2) > upstream regulatory region (URR) > E6 / E7 > E2 / L2 > E1 / L1.

CONCLUSIONS

These data provide estimates of the maximum viral genomic heterogeneity of alpha-7 HPV type variants. The proposed taxonomic system facilitates the comparison of variants across epidemiological and molecular studies. Sequence diversity, geographic distribution and phylogenetic topology of this clinically important group of HPVs suggest an independent evolutionary history for each type.

Reduced prevalence of oral human papillomavirus (HPV) 4 years after bivalent HPV vaccination in a randomized clinical trial in Costa Rica

Background

Human papillomavirus (HPV) infection, particularly with type 16, causes a growing fraction of oropharyngeal cancers, whose incidence is increasing, mainly in developed countries. In a double-blind controlled trial conducted to investigate vaccine efficacy (VE) of the bivalent HPV 16/18 vaccine against cervical infections and lesions, we estimated VE against prevalent oral HPV infections 4 years after vaccination.

Methods and Findings

A total of 7,466 women 18–25 years old were randomized (1∶1) to receive the HPV16/18 vaccine or hepatitis A vaccine as control. At the final blinded 4-year study visit, 5,840 participants provided oral specimens (91·9% of eligible women) to evaluate VE against oral infections. Our primary analysis evaluated prevalent oral HPV infection among all vaccinated women with oral and cervical HPV results. Corresponding VE against prevalent cervical HPV16/18 infection was calculated for comparison. Oral prevalence of identifiable mucosal HPV was relatively low (1·7%). Approximately four years after vaccination, there were 15 prevalent HPV16/18 infections in the control group and one in the vaccine group, for an estimated VE of 93·3% (95% CI = 63% to 100%). Corresponding efficacy against prevalent cervical HPV16/18 infection for the same cohort at the same visit was 72·0% (95% CI = 63% to 79%) (p versus oral VE = 0·04). There was no statistically significant protection against other oral HPV infections, though power was limited for these analyses.

Conclusions

HPV prevalence four years after vaccination with the ASO4-adjuvanted HPV16/18 vaccine was much lower among women in the vaccine arm compared to the control arm, suggesting that the vaccine affords strong protection against oral HPV16/18 infection, with potentially important implications for prevention of increasingly common HPV-associated oropharyngeal cancer.

ClinicalTrials.gov, Registry number NCT00128661

A prospective study of absolute risk and determinants of human papillomavirus incidence among young women in Costa Rica

Background

High risk human papillomaviruses (HR-HPV) are known to be extremely common, sexually transmitted infections, but more information is needed regarding the absolute risks of type-specific HR-HPV infections in the years following sexual debut.

Methods

We conducted a survival analysis of 3,737 women aged 18–25 from the control group of the Costa Rican Vaccine trial to determine the absolute risks of HR-HPV infections at 12 months, 24 months, and end of follow-up (average of 50.7 months). To corroborate determinants of infection, we used Cox proportional hazards methods to assess associations between demographics and sexual risk behaviors and incident HR-HPV.

Results

Cumulative incidence for HR-HPV infections was 51.3% at the end of the study period. The most common incident types were HPV52 (15.4%), HPV51 (13.6%), and HPV16 (12.4%). Type-specific cumulative incidence corresponded closely with type-specific prevalences, except that HPV16 was more prevalent than predicted by incidence, suggesting greater persistence. The strongest predictors of incident HR-HPV infections as a group in a multivariate analysis were the expected correlates of sexual behavior of the woman and her partner, such as being single (HR 1.6, 95% CI 1.4-1.8) or divorced/widowed (HR: 2.1, 95% CI: 1.7-2.7), having multiple HPV infections at enrollment (HR: 1.5, 95% CI: 1.3-1.7), and current smoking (HR: 1.2, 95% CI: 1.0-1.3). In women who reported being having only one lifetime sexual partner (being in a monogamous relationship), the strongest predictors of HR-HPV included not living with sex partner (HR: 2.1, 95% CI 1.7-2.5) and age of sex partner (HR: 1.4, 95% CI: 1.0-1.8).

Conclusion

We confirm the extremely high incidence of HR-HPV in young women, emphasizing the importance of vaccinating young girls before sexual debut.

Risk of precancer determined by HPV genotype combinations in women with minor cytologic abnormalities

BACKGROUND

Studies suggest that testing for individual human papillomavirus (HPV) genotypes can improve risk stratification in women with minor cytologic abnormalities. We evaluated genotyping for HPV16, HPV16/18, and HPV16/18/45 in carcinogenic HPV-positive women with atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL) cytology.

METHODS

For women enrolled in the ASCUS-LSIL Triage Study (ALTS), we calculated the age-stratified (<30 and 30+ years) positivity and cumulative risk over two years of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) when testing positive or negative for three genotype combinations: HPV16, HPV16/18, and HPV16/18/45.

RESULTS

Among women with ASCUS cytology, HPV16 positivity was 17.1% and increased to 22.0% (P < 0.001) for HPV16/18 and 25.6% (P < 0.001) for HPV16/18/45. Among women with LSIL cytology, HPV16 positivity was 21.1% and increased to 30.0% (P < 0.001) for HPV16/18 and 34.0% (P = 0.017) for HPV16/18/45. Regardless of cytology and age group, the greatest risk difference between test positives and test negatives was observed for HPV16 with decreasing risk stratification for HPV16/18 and HPV16/18/45. However, testing negative for any of the three combinations while being positive for another carcinogenic type still implied a two-year risk of CIN3+ of 7.8% or more.

CONCLUSIONS

Although genotyping for HPV16, 18, and 45 provided additional risk stratification in carcinogenic HPV-positive women with minor cytologic abnormalities, the risk among genotype-negative women was still high enough to warrant immediate colposcopy referral.

IMPACT

HPV genotyping in HPV-positive women with minor cytologic abnormalities will likely not alter clinical management. Adding HPV45 to genotyping assays is not warranted.

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.

Human papillomavirus and cancer prevention: gaps in knowledge and prospects for research, policy, and advocacy

The recognition that human papillomavirus (HPV) infection is the central, necessary cause of cervical cancer paved the way to new fronts of prevention via improved screening methods and HPV vaccination. Much has been learned in all fronts, from the molecular basis of our understanding of how HPV causes disease to the health economics of preventive strategies at the individual and population levels. Progress in other areas of cancer control has yet to show the same multi- and trans-disciplinary gains seen in research on HPV-associated malignancies, which is one of the unequivocal success stories in disease prevention. Yet, as an embarrassment of riches, much more research is needed to fill the gaps in knowledge that remain before we are able to reap the benefits from the knowledge translation from all fronts. Public health research on setting-specific implementation of HPV-based preventive strategies and more concerted advocacy to counter barriers facing the adoption of these strategies are likely to yield major dividends in reducing the burden of HPV-associated diseases. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

Cross-protective vaccine efficacy of the bivalent HPV vaccine against HPV31 is associated with humoral immune responses: results from the Costa Rica Vaccine Trial

BACKGROUND

We investigated the role of antibody responses as potential mechanism for the cross-protective vaccine-efficacies (VE) observed from randomized clinical trials of the HPV16/18 bivalent vaccine. Results HPV31 cases had lower HPV16 antibody levels than controls (OR 4th quartile compared with 1st quartile = 0.63; 95%CI: 0.36-1.08; p-trend = 0.03). HPV31 cases were also less likely to have detectable HPV31 neutralization, and HPV16 avidity than controls. No statistically significant differences by HPV18 antibody or HPV45 neutralization were observed among HPV45 cases and controls. Protection against HPV58 was not associated with any of the markers, confirming the specificity of our findings.

METHODS

Samples are from three-dose HPV vaccine recipients from the Costa Rica HPV16/18 vaccine trial. Women with a new HPV31, HPV45, or HPV58 infections over four years of follow-up were compared with randomly selected control women--with no new infection with HPV31/45/58--with respect to HPV16 and HPV18 antibody, HPV31, HPV45, and HPV58 neutralization, and HPV16 avidity.

CONCLUSIONS

High HPV16 levels and avidity, and the ability to neutralize HPV31 were associated with protection against newly detected HPV31 infections, suggesting that the partial VE demonstrated for HPV31 is likely to be mediated at least in part through antibodies induced by HPV16/18 vaccination.

Squamous cell carcinomas in patients with Fanconi anemia and dyskeratosis congenita: a search for human papillomavirus

Patients with Fanconi anemia (FA) and dyskeratosis congenita (DC) are at high risk of head and neck squamous cell carcinomas (HNSCC) and anogenital squamous cell carcinomas (SCC). In the general population, these sites (particularly oropharyngeal SCC) may be associated with infection with human papillomavirus (HPV). In FA and DC, however, the majority of HNSCC occur in the oral cavity. We investigated the HPV status of HNSCC and vulvar SCC from nine patients with FA and four with DC using a very sensitive PCR assay, and found HPV16 DNA in only a single vulvar tumor from one patient with FA, and in none of the HNSCC. These results suggest that HPV may not be the cause of SCC in patients with FA or DC, and that vaccination may not reduce the incidence of HNSCC in these patients.

Human papillomavirus infection and the multistage carcinogenesis of cervical cancer

This short review outlines our understanding of cervical cancer precursors, concentrating on the central etiologic role of persistent human papillomavirus infection. The stages of cervical carcinogenesis are better understood than for most other major cancers, providing a successful cancer etiology and prevention model.

Elevated methylation of HPV16 DNA is associated with the development of high grade cervical intraepithelial neoplasia

We explored the association of human papillomavirus type 16 (HPV16) DNA methylation with age, viral load, viral persistence and risk of incident and prevalent high grade CIN (CIN2+) in serially collected specimens from the Guanacaste, Costa Rica cohort. 273 exfoliated cervical cell specimens (diagnostic and pre-diagnostic) were selected: (1) 92 with HPV16 DNA clearance (controls), (2) 72 with HPV16 DNA persistence (without CIN2+) and (3) 109 with CIN2+. DNA was extracted, bisulfite converted and methylation was quantified using pyrosequencing assays at 66 CpGs across the HPV genome. The Kruskal-Wallis test was used to determine significant differences among groups, and receiver operating characteristic curve analyses were used to evaluate how well methylation identified women with CIN2+. In diagnostic specimens, 88% of CpG sites had significantly higher methylation levels in CIN2+ after correction for multiple tests compared with controls. The highest area under the ROC curve (AUC) was 0.82 for CpG site 6457 in L1, and a diagnostic sensitivity of 91% corresponded to a specificity of 60% for CIN2+. Prospectively, 17% of CpG sites had significantly higher methylation in pre-diagnostic CIN2+ specimens (median time of 3 years before diagnosis) versus controls. The strongest pre-diagnostic CpG site was 6367 in L1 with an AUC of 0.76. Age-stratified analyses suggested that women older than the median age of 28 years have an increased risk of precancer associated with high methylation. Higher methylation in CIN2+ cases was not explained by higher viral load. We conclude that elevated levels of HPV16 DNA methylation may be useful to predict concurrently diagnosed as well as future CIN2+.

A population-based study of visual inspection with acetic acid (VIA) for cervical screening in rural Nigeria

OBJECTIVE

Cervical cancer is the most common gynecological cancer in developing countries. Visual inspection with acetic acid (VIA) was introduced to screen for cervical premalignant lesions in developing countries owing to the inability of many countries to implement high-quality cytologic services. We sought to compare VIA performance among different health workers in Nigeria.

METHODS

In a population-based project, 7 health workers who had been screening women with VIA for approximately 2 years at local government health centers in rural Nigeria were retrained in a 2-week program using the International Agency for Research on Cancer training manual. Women from a rural village who had never had cervical cancer screening were recruited into the study. Each woman had cervical cancer screening by VIA, liquid-based cytologic test, and oncogenic human papillomavirus (HPV) DNA test.

RESULTS

Despite similar participant characteristics, across all age groups, providers had wide ranges of VIA results; 0% to 21% suspect cancer and 0% to 25% were VIA positive. Visual inspection with acetic acid was insensitive compared to a combination of cytologic and HPV tests.

CONCLUSION

In our study, VIA was not reproducible, nor was it sensitive compared to cytologic and HPV tests.