HPV16 E6 Antibodies Research Articles

Human papillomavirus (HPV) type 16 E6 seroprevalence among men living with HIV without HPV-driven malignancies.

Individuals living with HIV are at a higher risk for developing human papillomavirus-driven oropharyngeal squamous cell carcinoma (HPV+OPSCC). There are no methods for early detection; however, HPV16 E6 antibodies have been identified as a promising early marker. The objective of this study was to evaluate the prevalence of HPV16 E6 antibodies among men living with HIV, with secondary objectives of analyzing clinical and serologic predictors of HPV16 E6 seropositivity. Banked blood specimens from 2,320 men aged 40+ living with HIV in Tennessee were evaluated for the following HPV16 antibodies: L1, E1, E2, E4, E6, E7. HPV16 E6 antibody levels were further categorized as moderate or high. Demographic, clinical, and serologic determinants of HPV16 E6 seropositivity were evaluated using logistic regression. HPV16 L1 antibodies were most common (22.8%), followed by E4 (10.5%), E6 (5.6%), E2 (4.8%), and E7 (4.0%). Of the 130 HPV16 E6 seropositives, 55 (2.4%) had moderate seropositivity and 75 (3.2%) had high. HPV16 E6 seropositive men had nearly 2-fold greater odds of seropositivity against one additional HPV16 E antigen (OR: 1.67 [95% CI: 1.10-2.52]; P=0.015) and over 3-fold greater odds of seroreactivity against two additional HPV16 E antigens (OR: 3.21 [95% CI: 1.40-7.33]; P=0.006). HPV16 E6 seropositivity was not associated with the clinical or demographic factors evaluated. In the largest study to date, HPV16 E6 seroprevalence was elevated compared to prior studies in HIV populations (range: 1.1% to 3.2%) and likely reflects the high incidence of HPV+OPSCC in the southeast region of the United States.

Natural history of HPV16-E6 serology among cancer-free men in a multicenter longitudinal cohort study.

Human papillomavirus (HPV)16-E6 seropositivity accurately predicts oropharyngeal squamous cell carcinoma (OPSCC) risk decades before diagnosis; but the biomarker's translational potential is unknown. To inform considerations for OPSCC screening, we described HPV16-E6 seroprevalence, predictors, and kinetics among cancer-free men. In a cohort study in Brazil, Mexico, and United States, we calculated HPV16-E6 seropositivity [median fluorescence intensity (MFI) units > 1,000], measured by multiplex serology, in cancer-free men. HPV16-E6 seropositivity predictors were assessed using logistic regression, adjusting for country, age, sexual orientation, and lifetime number of partners. Among HPV16-E6 seropositive men, we retrieved all available retrospective serum samples and described temporal HPV16-E6 antibody patterns. Of 3,997 men, 14 had HPV16-E6 antibodies detected [seroprevalence = 0.35%; 95% confidence interval (95%CI)=0.19%-0.59%] (median MFI = 2,407; interquartile range = 1,325-5,986). Older age was associated with increased odds of HPV16-E6 seropositivity (50-84 years vs 18-29 years odds ratio = 16.61; 95%CI = 2.20-417.03). Serum from 11 of the 14 seropositive men retested positive; six men had MFI > 5,000, of whom two had MFI > 10,000. Seven men had ≥3 years follow-up; all were persistently seropositive for 3 years. One man was seropositive for nine years but seroreverted at his exit visit. Oral HPV16-DNA (prevalence = 1.13%) was associated with HPV16-E6 seropositivity (odds ratio = 16.87; 95%CI = 3.35-69.55). However, oral HPV16-DNA positivity was not persistent over follow-up, even when HPV16-E6 antibodies were persistently detected. HPV16-E6 seropositivity is rare but generally stable once detected; thus, HPV16-E6 antibodies may be an informative biomarker of HPV-driven OPSCC. Few men seroreverted following HPV16-E6 seropositivity but remained close to the seropositivity cut-off; thus, cancer risk among these men is less clear.

Detection of serum biomarkers of HPV-16 driven oropharynx and oral cavity cancer in Brazil

BackgroundHPV-16 driven oropharynx/oral cavity squamous cell carcinomas prevalence varies globally. We evaluated the presence of HPV-16 ctDNA and HPV-16 E6 antibodies in samples obtained from participants treated at the Instituto do Cancer do Estado de Sao Paulo, ICESP, and from whom tumoral HPV DNA, HPV-16 E6*I mRNA, and p16INK4a status was also accessed. MethodsHPV was genotyped by PCR-hybridization. All HPV DNA positive and ∼10 % HPV DNA negative cases underwent p16INK4a immunohistochemistry and E6*I RNA testing using a multiplex bead based protocol. HPV-16 ctDNA and anti-E6 antibodies were assessed by ddPCR (digital droplet PCR) and multiplex serology, respectively. ResultsThe prevalence of HPV-16 in oropharynx carcinoma (OPC) cases was low (8.7 %) when considering solely HPV-16 DNA detection, and even lower (5.2 %) when taken into consideration the concomitant detection of HPV-16 E6*I RNA and/or p16INK4 (HPV-16 attributable fraction - AF). None of the oral cavity cancer (OCC) cases were detected with HPV-16 DNA. HPV-16 ctDNA was more commonly detected than HPV-16 E6 antibodies (29.8 % versus 10.6 %). Both serum biomarkers attained 100 % sensitivity of detecting HPV-16 AF OPC, however the specificity of the HPV-16 anti-E6 biomarker was higher compared to ctDNA (93.2 % versus 75.0 %). Finally, when both HPV-16 ctDNA and anti-E6 biomarkers were considered together, the sensitivity and specificity for HPV-16 OPC detection was 100 % and about 70 %, respectively, independently of analyzing HPV-16 DNA positive or HPV-16 AF tumors. ConclusionsOur findings corroborate that serum biomarkers are highly sensitive and specific biomarkers for detection of HPV-associated OPC.

HPV types 16/18 L1 E6 and E7 proteins seropositivity and cervical cancer risk in HIV-positive and HIV-negative black South African women

BackgroundIn populations with high rates of human immunodeficiency virus (HIV)-coinfection, the nature of the relationship between human papillomavirus (HPV)-16 and -18 (L1, E6 and E7) antibodies and cervical cancer is still uncertain. We measured the association between seropositivity to HPV (L1, E6 and E7) proteins and cervical cancer among black South African women with and without HIV co-infection.MethodsWe used questionnaire data and serum collected from consecutively recruited patients with a newly diagnosed cancer from the Johannesburg Cancer Study from 1346 cervical cancer cases and 2532 controls (diagnosed with other non-infection related cancers). Seropositivity to HPV proteins was measured using a multiplex serological assay based on recombinant glutathione S-transferase (GST) fusion proteins. We measured associations between their presence and cervical cancer using unconditional logistic regression models and evaluated the sensitivity and specificity of these HPV biomarkers.ResultsAmong controls, HIV-negative women from rural areas compared to urban had significantly higher HPV seroprevalence, HPV16 E7 (8.6% vs 3.7%) and HPV18 E7 (7.9% vs 2.0%). HPV16 E6 and E7 antibodies were positively associated with cervical cancer in HIV-positive (Adjusted Odds Ratio (AOR) = 33; 95% CI 10–107) and HIV-negative women (AOR = 97; 95% CI 46–203). In HIV-positive women, HPV E6/E7 antibodies had low sensitivity (43.0%) and high specificity (90.6%) for cervical cancer detection. In HIV-negative women, HPV E6/E7 antibodies sensitivity was 70.6% and specificity was 89.7%.ConclusionsOur data show that HPV (L1, especially E6 and E7) antibody positivity is associated with cervical cancer in both HIV-positive and HIV-negative women. Nonetheless, being HIV-positive plays an important role in the development of cervical cancer.

Detection of Circulating HPV16 DNA as a Biomarker for Cervical Cancer by a Bead-Based HPV Genotyping Assay.

ABSTRACTHuman papillomavirus (HPV) circulating tumor DNA (HPV ctDNA) was proposed as a biomarker for the detection and disease monitoring of HPV-related cancers. One hundred eighty plasma samples obtained from women diagnosed with HPV16-positive cervical cancer (CC) (n = 100), HPV16-positive premalignant lesions (cervical intraepithelial neoplasia grade 3 [CIN3]) (n = 20), and HPV DNA-negative controls (n = 60) were randomly selected from the archives for evaluating the performance of a bead-based HPV genotyping assay (E7 type-specific multiplex genotyping assay [E7-MPG]) in detecting HPV16 ctDNA. The performance of the E7-MPG was compared with those of DNA detection by droplet digital PCR (ddPCR) and detection of HPV16 E6 antibodies evaluated in an independent study. Internal controls to assess DNA quality were included in the molecular assays, i.e., beta-globin and ESR1, respectively. The sensitivity and specificity of E7-MPG and/or E6 antibodies to detect HPV16-positive CCs were evaluated. HPV16 ctDNA was detected using the E7-MPG in 42.3% of all plasma samples and in 74.7% of plasma samples from HPV16-positive CC cases. The validation of E7-MPG data by ddPCR showed that the sensitivity of the E7-MPG test for HPV16-positive CC detection was higher than that of ddPCR (74.7% versus 63.1%; P < 0.001). When both HPV16 ctDNA and E6 antibodies were considered, the sensitivity for HPV16-positive CC detection increased from 74.7% to 86.1%, while the specificity was unchanged at 97.8%. The performance of E7-MPG for the detection of HPV16 ctDNA appears to be at least as sensitive as that of ddPCR, offering an additional tool for ctDNA detection of HPV16-positive CC. The use of an additional blood marker of HPV infection, such as E6 antibodies, further improved the detection of CC.IMPORTANCE The validity of HPV ctDNA as a marker of HPV-driven cancers has been previously reported. Herein we validated an alternative to ddPCR for HPV16 ctDNA detection, using a bead-based HPV genotyping assay that offers the potential advantage of reducing the cost of clinical management due to the multiplex capability of the test, thus facilitating its use in clinical settings. In addition, we analyzed HPV ctDNA in the context of E6 antibodies as an additional HPV marker. The HPV16 ctDNA biomarker appeared to be highly specific and, to a lesser extent, sensitive for the detection of CC, mainly indicated for those at an advanced tumor stage. In this proof-of-principle study, E6 antibodies were mainly detected in early tumor stages of CC, while HPV ctDNA was mainly positive at advanced tumor stages.

Blood-based biomarkers of human papillomavirus-associated cancers: A systematic review and meta-analysis.

Despite the significant societal burden of human papillomavirus (HPV)-associated cancers, clinical screening interventions for HPV-associated noncervical cancers are not available. Blood-based biomarkers may help close this gap in care. Five databases were searched, 5687 articles were identified, and 3631 unique candidate titles and abstracts were independently reviewed by 2 authors; 702 articles underwent a full-text review. Eligibility criteria included the assessment of a blood-based biomarker within a cohort or case-control study. One hundred thirty-seven studies were included. Among all biomarkers assessed, HPV-16 E seropositivity and circulating HPV DNA were most significantly correlated with HPV-associated cancers in comparison with cancer-free controls. In most scenarios, HPV-16 E6 seropositivity varied nonsignificantly according to tumor type, specimen collection timing, and anatomic site (crude odds ratio [cOR] for p16+ or HPV+ oropharyngeal cancer [OPC], 133.10; 95% confidence interval [CI], 59.40-298.21; cOR for HPV-unspecified OPC, 25.41; 95% CI, 8.71-74.06; cOR for prediagnostic HPV-unspecified OPC, 59.00; 95% CI, 15.39-226.25; cOR for HPV-unspecified cervical cancer, 12.05; 95% CI, 3.23-44.97; cOR for HPV-unspecified anal cancer, 73.60; 95% CI, 19.68-275.33; cOR for HPV-unspecified penile cancer, 16.25; 95% CI, 2.83-93.48). Circulating HPV-16 DNA was a valid biomarker for cervical cancer (cOR, 15.72; 95% CI, 3.41-72.57). In 3 cervical cancer case-control studies, cases exhibited unique microRNA expression profiles in comparison with controls. Other assessed biomarker candidates were not valid. HPV-16 E6 antibodies and circulating HPV-16 DNA are the most robustly analyzed and most promising blood-based biomarkers for HPV-associated cancers to date. Comparative validity analyses are warranted. Variations in tumor type-specific, high-risk HPV DNA prevalence according to anatomic site and world region highlight the need for biomarkers targeting more high-risk HPV types. Further investigation of blood-based microRNA expression profiling appears indicated.

Characterization of human papillomavirus (HPV) 16 E6 seropositive individuals without HPV-associated malignancies after 10 years of follow-up in the UK Biobank.

BackgroundAntibodies against the HPV16 oncoprotein E6 are promising biomarkers for HPV16-driven oropharyngeal cancer (HPV16-OPC) due to their high sensitivity and specificity, and prospective manifestation. In previous studies, 0•7% of controls without HPV-associated malignancies were HPV16 E6 seropositive of which only a minority is expected to develop HPV16-driven cancer. We aimed to characterise HPV16 E6 antibodies in individuals without HPV-associated malignancies.MethodsWe analysed serum antibodies against HPV16 E6, E7, L1 and HPV18 L1 in a random sample (n = 9,695) of the prospective UK Biobank cohort (UKB). Excluding individuals with potentially HPV-associated malignancies (n = 192), we assessed risk factors for seropositivity by logistic regression.FindingsIn individuals without potentially HPV-associated malignancies (n = 9,503), the HPV16 E6 seroprevalence was 0•8%. Seropositivity against HPV16 E6 and all other HPV antigens was strongly associated with sexual behaviour. The seroprevalence of HPV16 E6, L1 and HPV18 L1 increased with the number of lifetime sex partners (ptrend<0•005), and all HPV antibodies were associated with same-sex intercourse (ORE6 3•1, 95%CI 1•4–6•9; reference category: no same-sex intercourse). HPV16 E6 and L1 seropositivity were associated with young age (≤17 years) at sexual debut (ORE6 2•0, 95%CI 1•1–3•7) compared with individuals reporting sexual debut at age ≥20 years.InterpretationThis is the first study characterising HPV16 E6 antibodies in the general UK population. Their strong association with sexual behaviour, and overlapping risk factor profiles with other HPV antibodies support their relevance for HPV16-OPC disease prediction. However, additional risk stratification will be required to identify individuals at highest risk to develop HPV16-OPC.

Antibodies against HPV16E6 oncoprotein in the Swiss HIV cohort study: Kinetics and anal cancer risk prediction.

Our aim was to describe HPV16E6 antibody kinetics prior to anal cancer in people living with HIV/AIDS (PLWHA) and evaluate the possible contribution of HPV16E6 serology to anal cancer risk prediction. For 91 persons diagnosed with anal cancer in the Swiss HIV Cohort Study (1989-2017), serial serum/plasma samples were tested for HPV16E6 antibodies using multiplex serology, supplemented with samples from 1,356 participants without anal cancer. Anal cancer incidence was estimated for PLWHA from 40 years-old in the cART era, stratified by HPV16E6 serostatus. HPV16E6 seroprevalence was 23.3% in samples <2 years prior to anal cancer diagnosis and decreased with increasing time prior to cancer: 16.7% at 2-4 years, 4.4% at 5-9, and 7.0% at ≥10 years. Of 25 individuals with anal cancer who were HPV16E6-seropositive at any time during follow-up, the majority (n = 18) remained seropositive in all samples after seroconversion, whereas for seven cases, seropositivity was transitory. Among individuals with anal cancer, HPV16E6 seroprevalence was marginally higher in women vs. men who have sex with men (adjusted OR = 4.3, 95% CI: 1.1, 17.2) and in older participants (adjusted OR = 6.2, 95% CI: 1.1, 34.8 for cases diagnosed at ≥55 vs. <45 years). Anal cancer incidence was 402/100,000 person-years in HPV16E6-positive vs. 82/100,000 in HPV16E6-negative PLWHA (incidence rate ratio = 4.9, 95% CI: 1.3, 13.1). In conclusion, HPV16E6 serology, despite its low sensitivity, allows characterization of a group of individuals with very high anal cancer incidence and may have a place in secondary prevention in groups at high risk for anal cancer such as PLWHA.

Luciferase-Based Detection of Antibodies for the Diagnosis of HPV-Associated Head and Neck Squamous Cell Carcinoma.

Point-of-care tests are needed for the screening of head and neck squamous cell carcinoma (HNSCC) and other malignancies. Luciferase immunoprecipitation systems (LIPS), employing light-emitting proteins, were used to examine serum antibodies against several cancer-associated targets in blood donor controls and subjects with colon cancer (CC) and HNSCC. The assessment of antibodies against the wild type p53 tumor antigen showed that approximately 25% of the CC and 20% of the HNSCC patients were seropositive. In addition, humoral responses against two p53 mutants, p53-R175H and p53-R273H, generally tracked the antibody responses seen against wild type p53. Analysis of antibodies against highly specific biomarkers of HPV-16-associated malignancy, E2, E6, and E7 oncoproteins, revealed no seropositivity in blood donors and CC patients. However, 45% (9/20) of the HNSCC patients showed E6 seropositivity, which overlapped all the detectable E2 (40%; 8/20) and E7 seropositive subjects (35%; 7/20). Using neodymium magnets, ultrarapid LIPSTICKS testing of HPV-16 E6 antibodies in <60 s per HNSCC sample demonstrated almost the same diagnostic performance (40% sensitivity and 100% specificity) as LIPS testing in 2.5 h. While additional improvements and standardization are needed, these results highlight the possibility of using these approaches for the diagnosis of HPV-16-associated HNSCC.

Multiple imputation and clinico-serological models to predict human papillomavirus status in oropharyngeal carcinoma: An alternative when tissue is unavailable.

In cancer epidemiological studies, determination of human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (OPSCC) typically depends on the availability of tumor tissue testing, and/or tumor tissue access. Identifying alternative methods for estimating HPV status can improve the quality of such studies when tissue is unavailable. We developed multiple predictive models for tumor HPV status and prognosis by combining both clinico-epidemiological variables and either serological multiplex assays of HPV or multiple imputation of HPV status (HPVmi ). Sensitivity, specificity and accuracy of these methods compared to either p16 immunostaining (p16 IHC) or survival were assessed. When compared to a reference of tumor tissue p16 IHC in 783 OPSCC patients, the clinic-HPVsero model incorporating a composite of 20 HPV serological antibodies (HPVsero ) and 4 clinical factors (c-index: 0.96) performed better than using HPVsero (c-index: 0.92) or HPVmi (c-index: 0.76) alone. However, the model that contained a single HPV16 E6 antibody combined with four clinical variables, performed extremely well (clinic-s1-16E6; c-index: 0.95). When defining HPV status by HPVsero , s1-16E6, HPVmi or through p16 IHC, each of these definitions demonstrated improved overall and disease-free survival in HPV-positive OPSCC patients, when compared to HPV-negative patients (adjusted hazard ratios between 0.25 and 0.63). Our study demonstrates that when blood samples are available, a model that utilizes a single s1-16E6 antibody combined with several clinical features has excellent test performance characteristics to estimate HPV status and prognosis. When neither blood nor tumor tissue is available, multiple imputation, calibrated on local population characteristics, remains a viable, but suboptimal option.

Timing of HPV16-E6 antibody seroconversion before OPSCC: findings from the HPVC3 consortium.

BackgroundHuman papillomavirus type 16 (HPV16)-E6 antibodies are detectable in peripheral blood before diagnosis in the majority of HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), but the timing of seroconversion is unknown.Patients and methodsWe formed the HPV Cancer Cohort Consortium which comprises nine population cohorts from Europe, North America and Australia. In total, 743 incident OPSCC cases and 5814 controls provided at least one pre-diagnostic blood sample, including 111 cases with multiple samples. Median time between first blood collection and OPSCC diagnosis was 11.4 years (IQR = 6–11 years, range = 0–40 years). Antibodies against HPV16-E6 were measured by multiplex serology (GST fusion protein based Luminex assay).ResultsHPV16-E6 seropositivity was present in 0.4% of controls (22/5814; 95% CI 0.2% to 0.6%) and 26.2% (195/743; 95% CI 23.1% to 29.6%) of OPSCC cases. HPV16-E6 seropositivity increased the odds of OPSCC 98.2-fold (95% CI 62.1–155.4) in whites and 17.2-fold (95% CI 1.7–170.5) in blacks. Seropositivity in cases was more frequent in recent calendar periods, ranging from 21.9% pre-1996 to 68.4% in 2005 onwards, in those with blood collection near diagnosis (lead time <5 years). HPV16-E6 seropositivity increased with lead time: 0.0%, 13.5%, 23.7%, and 38.9% with lead times of >30 years (N = 24), 20–30 years (N = 148), 10–20 years (N = 228), and <10 years (N = 301 cases) (p-trend < 0.001). Of the 47 HPV16-E6 seropositive cases with serially-collected blood samples, 17 cases seroconverted during follow-up, with timing ranging from 6 to 28 years before diagnosis. For the remaining 30 cases, robust seropositivity was observed up to 25 years before diagnosis.ConclusionsThe immune response to HPV16-driven tumorigenesis is most often detectable several decades before OPSCC diagnosis. HPV16-E6 seropositive individuals face increased risk of OPSCC over several decades.

Prognostic value of posttreatment HPV-specific antibodies in patients with oropharyngeal tumors.

The presence of human papillomavirus (HPV)-specific antibodies in patients with head and neck cancer at enrollment has prognostic significance. In cervical carcinoma patients, the decrease of HPV E6/E7-specific antibodies appears to be associated with a better prognosis. This prospective study with follow-up focused on the persistence and prognostic value of antibodies specific for HR HPV-derived VLPs and HPV16 E6/E7 oncoproteins in patients with oropharyngeal cancers. In this study, we analyzed sera of 93 patients taken a year after the end of treatment and sera from 58 of these patients taken up to 14 years after treatment. The level of HPV-specific antibodies decreased on the 1-year follow-up and the decrease during the long follow-up was statistically significant. For HPV16 E7 antibodies the decrease was steeper in nonrecurrent patients. While the level of antibodies at enrollment was not predictive of recurrences, the decrease of HPV16 E6 antibodies at 1-year follow up was associated with better overall as well as disease-specific survival of patients. The data suggest that the pretreatment level of HPV-specific antibodies is not predictive of the occurrence of recurrences but the decrease HPV16 E6 antibodies on the 1-year follow-up is predictive of better survival of HN patients.

Post-treatment human papillomavirus antibody kinetics in cervical cancer patients.

Antibodies to the E6 and E7 oncoproteins of high-risk human papillomavirus (HPV) types are strongly associated with HPV-driven cancer, while antibodies against the capsid protein L1 are considered cumulative exposure markers. To test the hypothesis that L1 antibody levels are stable over time, whereas E6 and E7 levels undergo decay after cervical cancer (CxCa) treatment, we performed multiplex serology for HPV16 and 18 antigens E6, E7 and L1 in a post-treatment study of 184 patients with invasive CxCa that were characterized with a median follow-up time of 725 days, and 2-12 sera per patient. Antibody titers significantly decreased within the first six months for HPV16 E6 and E7 but not L1, and stabilized for the following 12 months on a high level, with few patients showing seroreversion. Of 67 patients seropositive for HPV16 E6 at diagnosis, 28 (41.8%) showed a decrease in antibody titers of at least 50% within the first 18 months. Similarly, of 50 HPV16 E7 seropositives, 33 (66.0%) showed decreasing antibody levels, whereas antibody decay was less frequent for HPV16 L1 (12 of 47, 25.5%). Using a power-law mathematical model to characterize antibody decay kinetics, the mean (±s.e.) durations to a 50% reduction in antibody titers within individual patients were estimated to be 56.9 (±26.1) and 56.3 (±19.0) days for HPV16 E6 and E7, respectively. In summary, HPV16 E6 and E7 antibodies undergo a slow but significant decrease in antibody titers within the first 6-18 months following CxCa treatment. However, larger studies are needed to confirm the utility of serology for prediction of disease progression and time to relapse based on antibody decay kinetics. This article is part of the theme issue 'Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses'.

Human Papillomavirus Seroprevalence and Association with Anal HPV Infection and Squamous Intraepithelial Lesions in Australian Gay and Bisexual Men.

Background: Gay and bisexual men (GBM) are at disproportionately high risk of anal cancer. The precursor lesions, high-grade squamous intraepithelial lesions (HSIL), are very common and it is evident that not all HSIL progresses to cancer. The serologic response to anal human papillomavirus (HPV) in GBM has not been well characterized.Methods: The Study of the Prevention of Anal Cancer is an ongoing cohort study of GBM ages 35 years and older. At six visits over three years, anal samples are collected for cytology, HPV DNA testing, and histology. Baseline serum was tested for HPV L1, E6, and E7 antibodies for 10 HPV types. Seroprevalence and associated predictors were analyzed.Results: A total of 588 of 617 participants were included in this analysis. A total of 436 (74.2%) were seropositive for at least one of the 10 HPV types. Almost half had L1 antibodies to HPV6 (48.5%), over a third to HPV11 (36.4%) and HPV16 (34.5%). HIV-positive men were more likely to be HPV L1 seropositive. HSIL detection was highest among participants who were HPV serology and DNA positive. There was a borderline significant association between presence of HPV16 E6 antibodies and prevalent HSIL (OR = 2.97; 95% confidence interval, 0.92-9.60; P = 0.068).Conclusions: HPV L1 seropositivity was common in this cohort of older GBM. These results suggest that HPV L1 seropositivity, in conjunction with anal HPV DNA detection, predicts concurrent HSIL. The apparent association between HPV16 E6 antibodies and prevalent HSIL is a finding with potential clinical significance that needs further exploration.Impact: HPV seropositivity with concurrent DNA detection predicted anal HSIL detection. Cancer Epidemiol Biomarkers Prev; 27(7); 768-75. ©2018 AACR.

Kinetics of the Human Papillomavirus Type 16 E6 Antibody Response Prior to Oropharyngeal Cancer.

In a European cohort, it was previously reported that 35% of oropharyngeal cancer (OPC) patients were human papillomavirus type-16 (HPV16) seropositive up to 10 years before diagnosis vs 0.6% of cancer-free controls. Here, we describe the kinetics of HPV16-E6 antibodies prior to OPC diagnosis. We used annual serial prediagnostic blood samples from the PLCO Cancer Screening Trial. Antibodies to HPV were initially assessed in prediagnostic blood drawn at study enrollment from 198 incident head and neck cancer patients (median years to cancer diagnosis = 6.6) and 924 matched control subjects using multiplex serology, and subsequently in serial samples (median = 5/individual). Available tumor samples were identified and tested for HPV16 RNA to define HPV-driven OPC. HPV16-E6 antibodies were present at baseline in 42.3% of 52 OPC patients and 0.5% of 924 control subjects. HPV16-E6 antibody levels were highly elevated and stable across serial blood samples for 21 OPC patients who were seropositive at baseline, as well as for one OPC patient who seroconverted closer to diagnosis. All five subjects with HPV16-driven OPC tumors were HPV16-E6-seropositive, and the four subjects with HPV16-negative OPC tumors were seronegative. The estimated 10-year cumulative risk of OPC was 6.2% (95% confidence interval [CI] = 1.8% to 21.5%) for HPV16-E6-seropositive men, 1.3% (95% CI = 0.1% to 15.3%) for HPV16-E6-seropositive women, and 0.04% (95% CI = 0.03% to 0.06%) among HPV16-E6-seronegative individuals. Forty-two percent of subjects diagnosed with OPC between 1994 and 2009 in a US cohort were HPV16-E6 seropositive, with stable antibody levels during annual follow-up for up to 13 years prior to diagnosis. Tumor analysis indicated that the sensitivity and specificity of HPV16-E6 antibodies were exceptionally high in predicting HPV-driven OPC.

Human papillomavirus antibody response following HAART initiation among MSM.

To describe effects of HAART on high-risk human papillomavirus (HPV) antibody response in HIV-positive MSM and the meaning of this response for subsequent HPV-related cancer risk. Prospective seroepidemiological study of 281 HIV-positive MSM initiating HAART between 1995 and 2004 in the Swiss HIV Cohort Study. For each individual, two serum samples, one at HAART initiation (pre-HAART) and another 24 months later (post-HAART), were tested for L1 antibodies to HPV6, 11, 16, 18, 31, 33, 35, 45, 52 and 58, as well as HPV16-E6 antibodies, using a multiplex serology assay. Identification of HPV-related cancer included data linkage with Swiss cancer registries. Pre-HAART, 45.2% were seropositive for any high-risk HPV-L1 and 32.4% for HPV16-L1. Sexual intercourse during the last 6 months was the only evaluated factor associated with L1 seropositivity pre-HAART. Seropositivity increased post-HAART to 60.5% for any high-risk HPV-L1 [prevalence ratio versus pre-HAART = 1.34, 95% confidence interval (CI) 1.14-1.57] and 48.0% for HPV16-L1 (prevalence ratio versus pre-HAART = 1.48, 95% CI 1.20-1.83), and seroconversion was significantly associated with both lower CD4 cell count and CD4/CD8 ratio (P < 0.01). Only one individual was HPV16-E6-seropositive pre-HAART, but two more seroconverted post-HAART. Anal cancer incidence among the three HPV16-E6-positives post-HAART was significantly increased compared with HPV16-E6-negatives (incidence rate ratio = 63.1, 95% CI 1.1-1211). HAART-related immune reconstitution increases HPV-specific antibody responses, which may discriminate future anal cancer risk in this high-risk population.

Human papillomavirus (HPV) 16 antibodies at diagnosis of HPV-related oropharyngeal cancer and antibody trajectories after treatment

ObjectivesDespite the fact that HPV-driven oropharyngeal cancer (HPV-OPC) has relatively low recurrence rates, intensive post-therapy monitoring remains the standard of care. Post-treatment biomarkers are needed to risk stratify HPV-OPC patients for more individualized surveillance intensity and which remain at higher recurrence risk. Materials and Methods115 HPV-OPC patients (ascertained by p16 immunohistochemistry and/or in-situ hybridization) from a multicenter prospective case study (HOTSPOT) had blood collected at diagnosis, and 64 of these also had blood collected at post-treatment follow-up visits for up to two years. Samples were centrally tested for antibodies to the L1, E1, E2, E4, E6, and E7 proteins of HPV16. ResultsAt diagnosis, most HPV-OPC cases were seropositive to HPV16 E6 (85%). In post therapeutic samples, HPV16 antibody level decreased slowly over time, but only 3 (of 51 cases seropositive at enrollment) dropped low enough to be classified as seronegative. At 3years after diagnosis, cumulative risk of recurrence was 10.2% and 0% in HPV16 E6 seropositive and E6 seronegative HPV-OPC cases, respectively (p=0.18). Risk of recurrence was increased, although not statistically significant, in those with higher HPV16 E6 antibody levels at diagnosis (per log antibody level, hazard ratio [HR]=1.81, 95%CI=0.47–6.92). ConclusionThis study confirms the high seroprevalence of HPV oncogenic antibodies at diagnosis of HPV-OPC. HPV16 E6 antibody levels decrease after treatment, but most cases remain seropositive for up to two years. HPV16 E6 antibody levels at diagnosis did not appear to be a strong predictor of recurrence.

Characterization of human papillomavirus antibodies in individuals with head and neck cancer

BackgroundHuman papillomavirus type 16 (HPV16) E6 antibodies are a promising biomarker of oropharyngeal cancer (OPC); however, seropositivity among non-OPC cases is not well characterized. MethodsPre-treatment sera from 260 (38 OPC, 222 non-OPC) incident head and neck cancers diagnosed at the University of Pittsburgh between 2003 and 2006 were tested for HPV16 (L1,E1,E2,E4,E6,E7) and non-HPV16 E6 (HPV6,11,18,33) antibodies. Sensitivity and specificity of HPV16 E6 antibodies for HPV-driven tumors was evaluated among tumors with known HPV status (n=25). Results63.2% of OPC versus 27.5% of non-OPC cases were HPV16 seropositive; HPV16 E6 seroprevalence was 60.5% and 6.3% respectively, odds ratio 22.8 (95% confidence interval [CI] 9.8⿿53.1). Sensitivity and specificity of HPV16 E6 antibodies for HPV-driven OPC was 100% [95% CI: 50⿿100%; n=6] and 100% [95% CI: 60⿿100%, n=4] compared to 0% (n=2) and 0% (n=13) for non-OPC cases. ConclusionsHPV16 antibodies were significantly more common in OPC versus non-OPC cases, particularly HPV16 E6 antibodies.

Serum Antibodies to HPV16 Early Proteins Warrant Investigation as Potential Biomarkers for Risk Stratification and Recurrence of HPV-Associated Oropharyngeal Cancer

Human papillomavirus (HPV) is responsible for increasing incidence of oropharyngeal cancer. At present, there are no biomarkers in the surveillance algorithm for HPV-positive oropharyngeal cancer (HPV-OPC). HPV16 E6 antibody precedes oropharyngeal cancer diagnosis. If HPV16 E6 indeed precedes primary diagnosis, it is similarly expected to precede disease recurrence and may have a potential role as a biomarker for surveillance of HPV-OPC. To determine whether HPV antibody titers have a potential role as early markers of disease recurrence or prognosis, a retrospective pilot study was designed to determine whether HPV16 early antibody titers E6, E7, E1, and E2 decrease after treatment of HPV16-positive OPC. Trends in pretreatment, early (≤6 months after treatment), and late posttreatment (>6 months after treatment) HPV16 antibody titers were examined. There were 43, 34, and 52 subjects with serum samples available for pretreatment, early, and late posttreatment intervals. Mean pretreatment antibody levels were higher than posttreatment antibody levels. Average antibody levels decreased significantly over time for E6 (Ptrend = 0.001) and E7 (Ptrend < 0.001). Six disease recurrences were observed during the follow-up period (median, 4.4 years). In univariate analysis, a log-unit increase in pretreatment E6 titer was significantly associated with increased risk of disease recurrence (HR, 5.42; 95% CI, 1.1-25.7; P = 0.03). Therefore, levels of antibodies to HPV16 early oncoproteins decline after therapy. Higher E6 titers at diagnosis are associated with significant increases in the risk of recurrence. These data support the prospective evaluation of HPV16 antibodies as markers of surveillance and for risk stratification at diagnosis.

Immunodeficiency and the risk of cervical intraepithelial neoplasia 2/3 and cervical cancer: A nested case-control study in the Swiss HIV cohort study.

HIV-infected women are at increased risk of cervical intraepithelial neoplasia (CIN) and invasive cervical cancer (ICC), but it has been difficult to disentangle the influences of heavy exposure to HPV infection, inadequate screening and immunodeficiency. A case-control study including 364 CIN2/3 and 20 ICC cases matched to 1,147 controls was nested in the Swiss HIV Cohort Study (1985-2013). CIN2/3 risk was significantly associated with low CD4+ cell counts, whether measured as nadir [odds ratio (OR) per 100-cell/μL decrease = 1.15, 95% CI: 1.08, 1.22], or at CIN2/3 diagnosis (1.10, 95% CI: 1.04, 1.16). An association was evident even for nadir CD4+ 200-349 versus ≥350 cells/μL (OR = 1.57, 95% CI: 1.09, 2.25). After adjustment for nadir CD4+, a protective effect of >2-year cART use was seen against CIN2/3 (OR versus never cART use = 0.64, 95% CI: 0.42, 0.98). Despite low study power, similar associations were seen for ICC, notably with nadir CD4+ (OR for 50 vs. >350 cells/μL= 11.10, 95% CI: 1.24, 100). HPV16-L1 antibodies were significantly associated with CIN2/3, but HPV16-E6 antibodies were nearly exclusively detected in ICC. In conclusion, worsening immunodeficiency, even at only moderately decreased CD4+ cell counts, is a significant risk factor for CIN2/3 and cervical cancer.