HPV-specific Antibodies Research Articles

Antibody avidity measurements in recipients of Cervarix® vaccine following a two-dose schedule or a three-dose schedule

The HPV-16/18 vaccine (Cervarix®) is a prophylactic vaccine for the prevention of cervical cancer and contains recombinant virus-like particles (VLPs) assembled from the L1 major capsid proteins of human papillomavirus (HPV) strains 16 and 18. Although a correlate of protection has yet to be identified, HPV-specific antibodies are thought to prevent virus infection of the genital mucosa. Therefore, antigen-specific antibodies as assessed by ELISA or pseudovirion-based neutralisation assay are frequently measured in clinical trials to substantiate the immune responses induced by the vaccine. Measuring antigen-antibody binding avidities, which reflects the degree of affinity maturation in the B-cells, is another valuable method to assess the quality of the antibody responses. Here we describe the antigen-specific antibody avidities in samples taken from a clinical trial examining the feasibility of adopting a two-dose (Months 0 and 6) schedule for 9–14 year olds instead of the three-dose schedule (Months 0, 1 and 6). Antibody avidity (i.e. avidity index [AI]) was determined in the ELISA by the ratio of antibody concentrations in serum samples treated or not with the chaotropic agent NaSCN. Importantly, in the comparison between the groups of two-dose and three-dose recipients, no differences in AIs were observed at Months 7, 24 and 48. The results suggest that from Month 7 to 48, the quality of the antibody response in terms of avidity was similar in the two-dose recipients to that in the three-dose recipients. Hence these results support the adoption of a two-dose schedule in 9–14 year-old girls.

What are the implications of human papillomavirus status in oropharyngeal tumors for clinical practice?

Human papillomavirus (HPV) status itself is an important and very probably the strongest prognostic factor in head and neck cancer. Because of the prognostic advantage of patients with HPV-positive cancers, the issue of the quality of life of survivors has become increasingly important. The possibility of treatment de-escalation in patients with virally induced tumors is being considered. Many challenges have to be addressed in order to integrate HPV status in the routine decision-making in patients with oropharyngeal cancer. The present review discusses the standardization of detection methods suitable for clinical use and the differences in predictive parameters between patients with HPV-positive and HPV-negative tumors. The gold standard for the identification of patients with oropharyngeal tumors etiologically linked to HPV infection is undoubtedly the detection of HPV 16 E6/E7 mRNA. The detection of a surrogate marker of active viral infection, p16ink4a, has a low sensitivity when used alone and must therefore be combined with the detection of HPV DNA or HPV-specific antibodies. The detailed knowledge of the importance of specific prognostic parameters is crucial in the choice of treatment. Nodal staging is probably much less important in HPV-positive cancers. It is of great importance to implement standardized testing for the identification of patients with HPV-induced oropharyngeal tumors. The treatment decision models in HPV-positive tumors have to take into account the probably different prognostic value of nodal parameters. Before introducing treatment de-escalation in patients with virally induced tumors into clinical practice, more research and clinical studies are needed.

Anal, Penile, and Oral High-Risk HPV Infections and HPV Seropositivity in HIV-Positive and HIV-Negative Men Who Have Sex with Men

The effects of single or multiple concordant HPV infections at various anatomical sites on type-specific HPV seropositivity are currently unknown. In this cross-sectional study we assessed whether high-risk HPV infections at various anatomical sites (i.e., anal canal, penile shaft, and oral cavity), as well as concordant infections at multiple anatomical sites, were associated with type-specific seropositivity in HIV-positive and HIV-negative MSM.MSM aged ≥18 years were recruited in Amsterdam, the Netherlands (2010–2011). Baseline anal, penile, and oral samples were analyzed for HPV DNA and genotyped using a highly sensitive PCR and reverse line blot assay. Virus-like particle (VLP) based multiplex immunoassay was used to asses HPV-specific serum antibodies against L1 VLPs. The associations between HPV infections and type-specific seropositivity of seven high-risk HPV types (7-hrHPV: types 16, 18, 31, 33, 45, 52, 58) were estimated using logistic regression analyses with generalized estimating equations. We found that 86% of 306 HIV-positive MSM and 62% of 441 HIV-negative MSM were seropositive for at least one 7-hrHPV type. 69% of HIV-positive and 41% of HIV-negative MSM were infected with at least one 7-hrHPV type at the anus, penis, or oral cavity. In multivariable analyses, 7-hrHPV seropositivity was associated with type-specific anal (and not penile) 7-hrHPV infection, and did not significantly increase with a higher number of infected anatomical sites. Oral 7-hrHPV infection showed a positive, albeit non-significant, association with seropositivity. In conclusion, seropositivity among MSM appears to be largely associated with anal HPV infection, irrespective of additionally infected anatomical sites.

Cervical Cancer in Women with Inflammatory Pap Smears

In spite of preventive measures such as Papanicolaou cervical cytological analysis and, more recently, vaccination against HPV infection, cancer of the uterine cervix continues to be one of the most frequent causes of mortality among women worldwide, particularly in developing countries. In this prospective study, sixty patients with inflammatory Pap smears had a colposcopy with directed biopsies. The average age of our patients was 42 years. Results showed that colposcopy is normal in 10% of women. It showed normal transformations, ectropion, a colpotis and polyp at 8.33%, 21.66%, 13.33% and 5% respectively. It was able to detect changes with Grade I atypical transformations (28.33%), and Grade II atypical transformations in 13.33% of cases. The biopsies were objectified dysplasia and carcinoma in 24.13% of cases with carcinoma in situ, micro invasive squamous cell carcinoma and invasive carcinoma glandular. Moreover, we detected HPV-specific antibodies in sera of these patients. Results showed that six patients (10%) showed a positive reactivity to at least one of the HPV-16 or HPV-18 antigens and sera showed different reactivity to the different antigens with the following percentages: 5%, 3%, 2%, 3% and 3% for L1 HPV-16, E6 HPV-16, E7 HPV-16, E6 HPV-18 and E7 HPV-18 respectively. Among patients having positive antibody response, 83.33% were cases of dysplasia and carcinoma. We concluded that the Pap smear, examination of key screening for cervical cancer, is a screening test without diagnostic value and more specifically any inflammatory Pap smear should be considered a positive test and led to further investigations. Moreover, colposcopy is an exam that is performed on an outpatient basis; it allows a detailed study of the cervix and reduces the negative rate of cytology. In addition, early detection of HPV antibodies could help the follow-up of patients.

Characteristics of HPV-Specific Antibody Responses Induced by Infection and Vaccination: Cross-Reactivity, Neutralizing Activity, Avidity and IgG Subclasses

ObjectivesIn order to assess HPV-specific IgG characteristics, we evaluated multiple aspects of the humoral antibody response that will provide insight in the HPV humoral immune response induced by HPV infection and vaccination.MethodsCross-reactivity of HPV-specific antibodies induced by infection or vaccination was assessed with VLP16 or 18 inhibition using a VLP-based multiplex immunoassay (MIA) for HPV16, 18, 31, 33, 45, 52 and 58. HPV16/18 specific IgG1-4 subclasses and avidity were determined with the VLP-MIA in sera after HPV infection and after vaccination. Neutralizing antibodies were determined in a small subset of single-seropositive and multi-seropositive naturally derived antibodies.ResultsNaturally derived antibodies from single-positive sera were highly genotype-specific as homologue VLP-inhibition percentages varied between 78-94%. In multi-positive sera, cross-reactive antibodies were observed both within and between α7 and α9 species. After vaccination, cross-reactive antibodies were mainly species-specific. Avidity of vaccine-derived HPV-specific antibodies was 3 times higher than that of antibodies induced by HPV infection (p<0.0001). IgG1 and IgG3 were found to be the predominant subclasses observed after HPV infection and vaccination. In the small subset tested, the number of single-positive sera with neutralizing capacity was higher than of multi-positive sera.ConclusionNaturally derived HPV-specific antibodies from single-positive samples showed different characteristics in terms of cross-reactivity and neutralizing capacity compared with antibodies from multi-positive sera. Post-vaccination, HPV antibody avidity was approximately 3 times higher than antibody avidity induced by HPV infection. Therefore, antibody avidity might be a potential surrogate of protection.

Comparison of Different Assays To Assess Human Papillomavirus (HPV) Type 16- and 18-Specific Antibodies after HPV Infection and Vaccination

We compared the measurement of human papillomavirus (HPV)-specific serum antibody levels with the virus-like-particle multiplex immunoassay (VLP-MIA), competitive Luminex immunoassay (cLIA), and glutathione S-transferase (GST) L1-based MIA. Using a large panel of serum samples, these assays showed mutually good correlations for both naturally induced and vaccine-derived HPV-specific antibody levels. However, an adaptation of the GST L1-based MIA resulted in an improved correlation with both cLIA and VLP-MIA.

Immunogenicity and safety of the bivalent HPV vaccine in female patients with juvenile idiopathic arthritis: a prospective controlled observational cohort study

ObjectivesTo compare the immunogenicity and safety of the bivalent human papillomavirus (HPV)16/18 vaccine between female patients with juvenile idiopathic arthritis (JIA) and healthy female adolescents.Methods68 patients and 55 healthy girls...

Markers of HPV infection and survival in patients with head and neck tumors

The purpose of this study was to determine whether changes in human papillomavirus (HPV) DNA prevalence in oral rinses and/or HPV-specific antibody levels in the sera of patients with oral/oropharyngeal cancer have prognostic significance. One hundred and forty-two patients with oral/oropharyngeal tumors were enrolled. The presence of HPV DNA was assayed in tumor tissue and oral rinses and HPV-specific antibodies were assessed in the sera. Oral rinses were collected before treatment and one year after the treatment. Sera were drawn before treatment, one month, and one year after the end of the treatment. Altogether, 59.2% of tumors were HPV positive. The presence of HPV DNA in the tumors correlated with HPV DNA positivity in oral rinses and with HPV-specific antibodies in the sera. Out of 66 patients with HPV-positive oral rinses at enrolment, 84.8% became negative at one-year follow-up, while most patients remained seropositive for HPV-specific antigens. However, the mean titers of HPV16 E6 and/or E7 antibodies at follow-up were significantly lower. Of 16 patients with recurrences at follow-up (alive on second sampling), six were positive at enrolment for HPV16 E6 and/or E7 antibodies. In five of these, no decrease in antibody levels was observed. Titers of antibodies specific for HPV16 capsid antigens did not change during the follow-up. Our data suggest that the detection of antibodies specific for the HPV 16 E6 and E7 oncoproteins may serve not only as a marker of HPV etiology, but also as a marker of recurrence and a prognostic indicator in patients with HPV-positive tumors.

OP089: Clinical importance of HPV markers in the follow up of patients with head and neck tumors

The purpose of this study was to determine the correlation between the presence of HPV DNA in tumor tissue and its presence in oral rinses and between the presence of HPV DNA in tumor tissue and HPV specific antibody levels in sera. The second goal was to find out whether changes in HPV DNA prevalence in oral rinses and/or HPV-specific antibody levels in sera of patients with HPV positive tumors have prognostic significance. One hundred forty-two patients with oral/oropharyngeal tumors were enroled. The presence of HPV DNA was assayed in tumor tissue and oral rinses, and HPV-specific antibodies were assessed in sera. Oral rinses were collected before treatment and one year after treatment. Sera were drawn before treatment, one month and one year after the end of treatment. Altogether, 59.2% tumors were HPV positive. The presence of HPV DNA in the tumors strongly correlated with HPV DNA positivity in oral rinses as well as with the presence of HPV—specific antibodies in sera. All markers of HPV infection at enrollment were predictive of better survival and lower frequency of recurrences. A majority of patients cleared their HPV infection in oral rinses after treatment. Out of 66 patients with HPV positive oral rinses at enrollment, 84.8% became negative at one-year follow-up, while most patients sustained their seropositivity for HPV specific antigens. However the mean titers of HPV 16 E6 and E7 antibodies at follow-up were lower in comparison to those at enrollment and the differences were statistically significant. Of 16 patients with recurrences on the follow-up (alive at the time of second sampling), six were positive at enrollment for HPV 16 E6 and/or E7 antibodies. In five of these, no decrease in antibody levels was observed. In all patients titers of antibodies specific for HPV 16 capsid antigens did not change during the follow up. Our data suggest that the detection of seropositivity for HPV-specific antibodies to the HPV 16 E6 and E7 oncoproteins may serve not only as a marker of the HPV etiology, but also as a marker of recurrence and a prognostic indicator in patients with HPV positive tumors. Grant sponsor for this study was Granting Agency, Ministry of Health, Czech Republic with Grant No.: NT/12483.

Patterns of Human Papillomavirus DNA and Antibody Positivity in Young Males and Females, Suggesting a Site-Specific Natural Course of Infection

BackgroundTo monitor the impact of human papillomavirus types 16 and 18 vaccine on HPV infection dynamics in the Netherlands, we started an ongoing study in sexually transmitted infection (STI) clinics in 2009. Here, we analyze baseline type-specific HPV DNA and HPV-specific antibody positivity rates.MethodsWe enrolled 3569 men and women, 16–24 years of age, from 14 STI clinics, and estimated genital and anal HPV DNA and antibody positivity rates of 7 main carcinogenic HPV types. Generalized estimating equations regression analyses were applied to determine risk factors for, and associations between, type-specific HPV DNA and antibody positivity.ResultsGenital HPV DNA positivity rates were higher in women than in men; anal HPV DNA was especially high in men who have sex with men (MSM). HPV antibody seropositivity rates were also highest in women and MSM. High-risk sexual behavior was predictive of both HPV DNA and antibody positivity. Despite a strong correlation in serological profiles for multiple HPV types, seropositivity was independently associated with homologous HPV DNA detection.ConclusionsHPV DNA and antibody positivity rates are higher in women and MSM than in heterosexual men, but their association is similar across gender. This suggests a site-specific natural course of infection.

Detection of systemic and mucosal HPV-specific IgG and IgA antibodies in adolescent girls one and two years after HPV vaccination

The bivalent HPV16/18 vaccine induces high antibody concentrations in serum while data about antibody responses in the cervix are limited. In this study, we investigated pre- and post-vaccination antibody responses against seven high-risk HPV types by detection of IgG and IgA HPV-specific antibodies in cervical secretion samples (CVS) and serum. From an HPV vaccine monitoring study CVS and serum samples were available (pre-vaccination (n = 297), one year (n = 211) and two years (n = 141) post-dose-one vaccination) from girls aged 14–16 y. The girls were vaccinated with the bivalent HPV vaccine at months 0, 1 and 6. CVS was self-sampled using a tampon. Samples were tested for HPV-specific antibodies (HPV16/18/31/33/45/52/58) by a VLP-based multiplex immunoassay. Post-vaccination, IgG and IgA antibody levels for HPV16/18 were detectable in CVS and amounted to 2% and 1% of the IgG and IgA antibody levels observed in serum, respectively. The antibody levels remained constant between one and two years after vaccination. The correlation between CVS and serum was similar for IgG and IgA vaccine-derived antibody levels for HPV16 (rs = 0.58, rs = 0.54) and HPV18 (rs = 0.50, rs = 0.55). Vaccine-derived IgG antibody levels against cross-reactive HPV types in CVS and in serum were highest for HPV45. No IgA cross-reactive antibody responses could be detected in CVS. Post-vaccination, HPV16/18 IgG and IgA antibodies are not only detectable in serum but also in CVS. The correlation of HPV16/18 IgG antibody levels between serum and CVS suggests that vaccine induced HPV antibodies transudate and/or exudate from the systemic circulation to the cervical mucosa to provide protection against HPV infections.

Changes in Antibody Seroprevalence of Seven High-Risk HPV Types between Nationwide Surveillance Studies from 1995–96 and 2006–07 in The Netherlands

ObjectiveThis study evaluates trends in antibody seroprevalences of seven high-risk human papillomavirus (hr-HPV) serotypes (HPV16, 18, 31, 33, 45, 52, and 58) between the 1995–96 and 2006–07 sero-surveys among the Dutch general population in the pre-vaccination era.MethodsSerum samples of men and women (0–79 years of age) from two cross-sectional population-based serosurveillance studies performed in 1995–96 (n = 3303) and 2006–07 (n = 6384) were tested for HPV-specific antibodies in a VLP-based multiplex immunoassay.ResultsHPV16-specific antibody seroprevalence increased during adolescence and shifted to younger ages in the 2006–07 survey compared to the 1995–96 survey. This step-up in HPV16 seroprevalence was most pronounced in women, while a more gradual increase was observed in men. Also in cohorts older than 49 years, HPV16 seroprevalence was higher in 2006–07 as compared to 1995–96 survey. A higher overall seroprevalence in individuals older than 15 years of age was found for HPV16, 18, 31 and 45 in 2006–07 as compared to 1995–96. For HPV33, 52 and 58 seroprevalences were comparable over this 11-year time period. Seropositivity for one or more HPV types was significantly higher in 2006–07 (23.1%) than in 1995–96 (20.0%) (p = 0.013). Multi-seropositivity increased from 7.1% in 1995–96 up to 10.2% in 2006–07 (p<0.0001). Differences in HPV seropositivity for at least one of the seven HPV types between both surveys could be explained in addition to demographic characteristics (age, sex, urbanization degree and ethnicity), also by changes in sexual behaviour (marital status, age of sexual debut and ever reported an STI).ConclusionThe observed increase in particular HPV16 seroprevalence could be due to changes in sexual behaviour over the years, and especially in age of sexual debut. Seroprevalence studies provide insight into the distribution of HPV types and infection dynamics in the general population over time, which is important to assess the impact of HPV-vaccination.

Post-vaccination anti-human papillomavirus antibody seroprevalence among Czech teenaged girls and women

ObjectiveTo evaluate seroprevalence among Czech girls and women previously vaccinated against human papillomavirus (HPV). MethodsA commercial enzyme-linked immunosorbent assay was used to determine the level of antibodies and seropositivity, with no genotype specification. ResultsA group of 356 teenaged girls and women with a mean age of 19.5years (95% confidence interval [CI], 18.9–20.1years) was found to have 94.1% HPV seropositivity (95% CI, 91.1%–96.3%) up to 3.5years after vaccination. The vaccine-specific total seropositivity rates were 98.0% and 85.0% among quadrivalent vaccinees (Gardasil; Merck, Whitehouse Station, NJ, USA) and bivalent vaccinees (Cervarix; GlaxoSmithKline, Brentford, UK), respectively. Adjusting for age and post-vaccination time period, an expected 2:1 (quadrivalent:bivalent) ratio of the geometric mean concentrations of total HPV-specific antibodies induced by the vaccines was observed. The antibody avidity remained almost unchanged up to 3.5years later. Nevertheless, the mean avidity index was significantly higher among quadrivalent vaccinees (2.50M GuHCl/mL; 95% CI, 2.42–2.58M GuHCl/mL) than bivalent vaccinees (2.09M GuHCl/mL; 95% CI, 2.01–2.17M GuHCl/mL). ConclusionHigh anti-HPV seroprevalence at a level related to the valency of vaccine used was achieved among Czech teenaged girls and women up to 3.5years after vaccination.

HPV persistence and its oncogenic role in prostate tumors

HPV has carcinogenic effects at several anatomical sites in women and men. Whether the presence of HPV in the genitourinary tract of men is associated with a higher prostate cancer risk has been a matter of research for a long-time and the results are still not fully conclusive. Similarly, the question of the reservoir of HPV infection in men is not clearly resolved. HPV DNA presence and types were evaluated by means of polymerase chain reaction in the tissue of 146 patients with benign prostate hyperplasia and prostate cancer. HPV-specific antibodies were analyzed by enzyme-linked immunosorbent assay in the sera of all patients and 172 controls. In addition, 256 biopsies taken from non-tumorous tissues were analyzed. No statistically significant differences were observed in HPV DNA prevalence between patients with benign prostate hyperplasia (2%) and patients with prostatic cancer (2%; P = 1.000). The seropositivity rates did not differ significantly between groups of subjects except for antibodies against HPV 6 VLPs which were found more often in prostate cancer patients (adjusted P = 0.018). Similarly, no difference in the seroprevalence rates for HPV 16 E6 and/or E7 oncoproteins between groups of patients and healthy controls was detected. The overall HPV prevalence in 256 healthy tissue samples was 4%. The results indicate that HPV infection is not associated with prostate oncogenesis in men. However, they imply that multiple tissues of the male genitourinary tract may be important reservoirs for the transmission of some HPV types.

Development and application of a GuHCl-modified ELISA to measure the avidity of anti-HPV L1 VLP antibodies in vaccinated individuals

Antibody responses against infectious agents are an important component in the prevention of disease. The avidity of antibodies for their antigens relates to their functional efficiency, and is a fundamental aspect in the investigation of humoral responses. Modified ELISAs are used to estimate avidity through the use of chaotropic agents and the measurement of the degree to which they disrupt the interaction between antibody and antigen. The theory behind the assay is the higher the avidity of an interaction the less susceptible it is to the effects of the chaotropic agent. The goal of this study was to generate a modified ELISA where a complex, multimeric coating-antigen, human papillomavirus (HPV) virus-like particles (VLP), was used to measure the avidity of anti-HPV antibodies generated following vaccination with HPV VLPs. A series of chaotropic agents were evaluated in the assay for their effectiveness in measuring avidity. Guanidine hydrochloride (GuHCl) was selected as a chaotropic reagent with the ability to disrupt antibody and antigen interactions, while not affecting the integrity of the plate-bound VLP. Two methods of determining the avidity index were assessed and shown to be comparable. This assay was then successfully applied to measure the avidity of anti-HPV VLP serum antibodies in samples from an HPV L1 VLP vaccine clinical trial. Overall, the assay was highly reproducible and captured a wide range of antibody avidities. Therefore, a GuHCl-modified ELISA is an acceptable method that can be used to determine HPV-specific antibody avidity indices within a clinical trial setting.

Less Is More: A Step in the Right Direction for Human Papillomavirus (HPV) Vaccine Implementation

Although immunization with two highly efficacious human papillomavirus (HPV) vaccines holds great promise for reducing the global burden of HPV-related cancers, the barriers to achieving this goal remain substantial. The cost of HPV vaccination still represents an important obstacle to implementation in many countries but there are several challenges beyond the high cost (1). It has proven difficult to achieve high levels of coverage with all three HPV vaccine doses even in countries with considerable resources. In the United States, where HPV vaccine delivery is principally by primary care physicians, the uptake of the complete three-dose series of HPV vaccine was recently estimated at 32% among 13- to 17-year-old girls (2). This low rate of series completion contrasts with the outstanding successes in Australia and the United Kingdom where school-based HPV vaccine programs have achieved much higher rates of coverage for the third HPV vaccine dose (≥72% and ≥84%, respectively) in the primary target population of 12- and 13-year-old girls (3,4). Functional and routine preventive health-care platforms are nearly nonexistent for adolescents worldwide, therefore school-based immunization programs, where feasible, can provide a solution to achieving high vaccine coverage. Beyond providing a venue for adolescent immunization, evidence from England (4) suggests that school-based HPV vaccine delivery can achieve equity in coverage of 12-year-old girls across deprivation levels of the areas where they live. In the United States, HPV vaccination rates have been strongly and inversely correlated with cervical cancer mortality rates and median income (5). Because cervical screening coverage is inversely associated with poverty and deprivation (6), ensuring equitable HPV vaccine delivery and high coverage in populations that are less likely to have opportunities for cervical screening as adults remains a priority. In addition to problems associated with the cost and organizational challenges of HPV vaccine delivery, there has been little to no information available to examine potential alternative immunization schedules or the efficacy of HPV vaccination with less than the recommended full three-dose series. Sustained immunogenicity and immune memory has been demonstrated following administration of two doses of the hepatitis B vaccine (7), and preliminary data on HPV-specific antibody titers have suggested that two HPV vaccine doses may be equivalent to three (8). However, experts have speculated that a single dose of the HPV vaccine, like other recombinant subunit vaccines, is unlikely to be efficacious. In this issue of the Journal, Kreimer et al. (9) present the first clinical evidence to support the efficacy of fewer than three doses of the bivalent HPV16/18 vaccine. The Costa Rica Vaccine Trial, in which this study was nested, was not specifically designed to measure vaccine efficacy (VE) when less than the complete threedose HPV vaccine series was delivered. Thus, the main reasons that participants in this analysis did not receive three doses were involuntary, including pregnancy and colposcopy referral; few participants refused vaccination. After a median follow-up time of 4.2 years, two doses of the bivalent HPV vaccine demonstrated high VE against incident HPV16 and HPV18 infections that persisted for at least 1 year (VE = 84.1%, 95% confidence interval [CI] = 50.2% to 96.3%), and even a single dose was highly efficacious (VE =100%, 95% CI = 66.5% to 100%). The VE for two and three doses was essentially the same. Importantly, the VE estimates are supported by similar attack rates of incident HPV16 or HPV18 infections that persisted for 1 year among women who received one dose (5.3%), two doses (4.5%), or three doses (4.4%), indicating that they were at similar risk for acquiring HPV infections regardless of the number of doses. Cross-protection against the composite endpoint of incident 1-year persistent infection by HPV31, HPV33, and HPV45 has been reported previously (10) for women who received the standard three-dose regimen of the bivalent HPV vaccine (VE = 41.3%, 95% CI = 18.9% to 57.9%). Kreimer et al. (9), however, show no evidence of vaccine cross-protection in women who received two doses of the HPV16/18 vaccine (VE = 225.9%, 95% CI = 2334% to 61.1%), and although the data are limited, they do suggest that

HPV involvement in tonsillar cancer: Prognostic significance and clinically relevant markers

The association of high-risk human papillomaviruses (HR HPVs) with tonsillar cancer (TC) has been documented. Because patients with HPV-associated tumors show better survival rates, modification of their treatment regimen is being considered. It is therefore crucial to find markers for the identification of patients whose tumors are linked to viral infection. A cohort of 109 patients with primary TC was screened for HPV DNA presence in the tumor tissues and HPV-specific antibodies in sera. Data regarding risk factors and clinical parameters were collected. Forty-five specimens were analyzed for the expression of viral E6 and E2-region mRNA, and the p16 and p53 protein expression status was assessed by immunohistochemistry. The overall prevalence of HPV DNA in TC tissues was 65.1%. Ninety-three percent of HR HPV DNA-positive samples expressed E6*I mRNA. E2-region mRNA expression was detected in 36% of positive samples, which implies that the virus is integrated in 64% of HPV DNA/RNA-positive tumors. p16 overexpression and the presence of antibodies specific to HPV16 E6/E7 oncoproteins correlated well with HPV DNA and RNA presence. The disease-specific survival rate of patients with HPV DNA-positive tumors was significantly higher than that of HPV DNA-negative patients. In addition to providing further evidence of the involvement of HPV infection in the etiopathogenesis of a proportion of TC cases, our study demonstrates that p16 immunostaining and anti-E6/E7 antibodies as surrogate markers of HPV involvement represent specific, sensitive and clinically accessible assays for the identification of TC patients who have a considerably better prognosis.

A quadrivalent HPV vaccine induces humoral and cellular immune responses in WHIM immunodeficiency syndrome

WHIM-syndrome is an inherited immunodeficiency disorder with abnormal susceptibility to human papillomavirus (HPV) infection and diseases. We determined safety and immunogenicity to a quadrivalent HPV vaccine in WHIM-syndrome by detection of HPV-specific antibodies and lymphoproliferation. In virus-like-particle (VLP)-ELISA, a WHIM patient showed antibody titers up to 400 for HPV-6/11/16/18, whereas immuno-competent controls developed titers of 6400–25,600. In pseudovirion assays, the patient's neutralization titers ranged from 20 to 400 to the four HPV vaccine types, while titers of 1600–25,600 were detected in healthy vaccinees. Specific proliferation of PBMC of the WHIM patient to the HPV vaccine was demonstrated. This first report on response to HPV vaccination in WHIM-immunodeficiency highlights that patients with WHIM-syndrome, and probably other immunodeficiencies, may benefit from HPV immunoprophylaxis.

Demographic and risk factors in patients with head and neck tumors

The association between human papillomavirus (HPV) infection and the development of head and neck cancer has been documented recently. In this study on 86 head and neck cancer patients and 124 controls, data regarding demographics, behavioral risk factors, and risks related to HPV exposure were collected. HPV detection was carried out using polymerase chain reaction in the tumors and in oral exfoliated cells, and HPV typing by a reverse line blot assay specific for 37 HPV types. Sera were tested by an enzyme-linked immunosorbent assay specific for HPV proteins. Head and neck cancer cases report significantly more oral-anal contact (P = 0.02) and tobacco and alcohol use than controls (P = 0.001; P = 0.02, respectively). High-risk HPV DNA was detected in 43% of oral washings of cases and 4% of controls (P < 0.0001). The association between the presence of high-risk HPV DNA in oral exfoliated cells and in tumor tissues was statistically significant (adjusted P < 0.0001). The prevalence of HPV-specific antibodies was significantly higher in cases than in controls (adjusted P < 0.0001). These results provide epidemiological and immunological evidence for HR HPV as a strong risk factor (OR = 44.3, P < 0.0001) for head and neck cancer, even after controlling for age, tobacco and alcohol use. The detection of high-risk HPV DNA in oral exfoliated cells and HPV-specific antibodies in serum can be considered as clinically relevant surrogate markers for the presence of a HPV-associated head and neck cancer, with a high sensitivity (83%) and specificity (88%).

Serological study in Tunisian cervical cancer patients

Objective The aim of this study is to use a novel ELISA, based on five recombinant HPV-16 and HPV-18 proteins, for detection HPV-specific antibodies in a case-control study. Patients and methods L1, E6 and E7 genes have been over expressed in Escherichia coli as double fused proteins. These recombinant proteins were used in a GST-capture ELISA as coating antigens. Human sera were collected from women with cervical cancer. Negative human sera were collected from patients apparently healthy and may be affected by other infectious agents. Results Most of the sera showed a positive reactivity to at least one of the HPV-16 or HPV-18 proteins (52/71). A percentage of 39.50% of the sera from HPV-16 infected women and 21.12% of the sera from women infected by HPV-18 genotype recognised at least one of the HPV-16 or HPV-18 proteins. Sera showed different reactivity to L1, E6 and E7 antigens, and only a few serum samples reacted to L1, E6 and E7 HPV-16, E6 and E7 HPV-18 (co-infection). Differences of reactivity between cases and controls were significant ( P < 0.0001). Conclusion This novel ELISA, based on recombinant HPV-16 and HPV-18 antigens, is able to detect antibodies in women infected by HPV genotypes. The assay is easy to perform and has low cost, making it suitable for monitoring the natural history of HPV infections as well as for detecting pre-existing HPV antibodies in women who receive vaccination.