Immunoglobulin G responses against human papillomavirus type 16 virus-like particles in a prospective nonintervention cohort study of women with cervical intraepithelial neoplasia

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

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

Seropositivity to Multiple Anogenital Human Papillomavirus (HPV) Types Is Associated With Current Anogenital HPV Infection, Abnormal Cytology, and Seropositivity for Nongenital HPVs

Background

Antibodies against human papillomaviruses (HPVs) are biomarkers for current or past infections. We assessed whether antibodies against multiple HPV types were determinants of current multiple anogenital HPV infections, abnormal cytology, and seropositivity for cutaneous HPVs.

Methods

A total of 1848 Slovenian women attended 2 rounds of cervical cancer screening 3 years apart and provided data on HPV antibodies and HPV DNA at both visits. Antibodies against 15 anogenital HPV types and 6 cutaneous HPVs were determined using pseudovirion-Luminex serology and anogenital HPV DNA using Linear Array. Antibodies to polyomaviruses were evaluated as a control. Women were grouped as either HPV seronegative or having antibodies to 1-2 HPV types or to ≥3 HPV types.

Results

Presence of antibodies to multiple anogenital HPV types at baseline was associated strongly with (i) presence of HPV DNA at the cervix (χ2 = 68.8; P < .0001), (ii) multiple types of HPV DNA at baseline (χ2 = 58.6; P < .0001), (iii) HPV DNA at follow-up (χ2 = 22.9; P < .0001), (iv) abnormal cytology (χ2 = 9.8; P = .0017), and (v) concomitant presence of antibodies to any of 6 nongenital HPV types (χ2 = 40.1; P < .0001). Presence of antibodies to ≥3 anogenital HPV types tended to persist over time.

Conclusions

Seropositivity against at least 3 anogenital HPV types is associated with current multiple anogenital HPV infections, abnormal cytology, and seropositivity to nongenital HPVs.

Association between interleukin-2, interleukin-10, secretory immunoglobulin A and immunoglobulin G expression in vaginal fluid and human papilloma virus outcome in patients with cervical lesions

The present study was designed to investigate the association between a change in vaginal local immunity and human papilloma virus (HPV) infection outcome in patients with cervical lesions, through the study of the expression of vaginal local immune factors, interleukin (IL)-2, IL-10, secretory immunoglobulin A (sIgA) and IgG, in patients with different grades of cervical lesions and different degrees of cervical lesions caused by HPV infection prior to and following treatment. The experimental group comprised 136 patients with low-grade squamous intraepithelial lesions, 236 patients with high-grade squamous intraepithelial lesions and 133 patients with cervical squamous cell carcinoma, while the control group comprised 100 time- and location-matched healthy women. The concentrations of sIgA, IgG, IL-2 and IL-10 in the vaginal lavage fluid, were detected using ELISA prior to treatment and at 3, 6 and 12 months after treatment. Prior to treatment, differences in HPV infection rate and changes in vaginal immune factors between patients with all grades of lesions and controls were statistically significant (P<0.05). Furthermore, IL-2 and IL-10 expression levels and the IL-2/IL-10 ratio in patients with different grades of lesions, with or without seroconversion, were significantly different to those in controls (P<0.05). However, the differences between changes in IgG and sIgA expression between patients with HPV seroconversion and patients with persistent HPV infection were not statistically significant (P>0.05). The results of the present study suggest that the restoration of humoral immune function promotes HPV seroconversion, and that IL-2 and IL-10 levels and their ratio may reflect the severity of cervical lesions and treatment effects to a certain extent.

A Serological Epidemiological Survey of Antibodies against 4 HPV Subtypes in Uygur Women in Xinjiang

This study evaluated the distribution of antibodies against 4 human papillomavirus (HPV) subtypes and their related factors among Uygur women in Xinjiang. A cross-sectional study was conducted from March 2006 to May 2007 involving 883 Uygur women aged 17-54 years living in Yutian County. Demographic indicators, disease history, sexual behavior history, and other parameters were recorded at the interview using a questionnaire. A fluorescence detection method was used to quantify anti-HPV6, -11, -16, and -18 antibodies in venous blood serum. The rate of positive detection of any anti-HPV antibody (anti-HPV6, -11, -16, and -18) in the study population was 13.4%, and the individual positivity rates were 9.5%, 2.6%, 4.3%, and 0.7%, respectively. Peak rates of positivity for the anti-HPV16 antibody were found in women who were 36-40 and 46-50 years old. Seroprevalence of HPV16, which is high-risk for cervical cancer, was associated with the numbers of sexual partners. The rate of infection with high-risk HPV was low among Uygur women from rural areas, although there is a high incidence of cervical cancer in this group. Loyalty to one sexual partner decreased the risk of high-risk HPV infection. This study may provide useful reference data for the prevention and treatment of HPV and cervical cancer and for the application of HPV vaccines.

Human papillomavirus DNA positivity and seropositivity in rural Chinese men and women: a population-based cross-sectional study

Data on simultaneous analysis of human papillomavirus (HPV) DNA and serology and the correlations within a single general population are limited. Among 1603 men and 2187 women enrolled from rural China, serum antibodies against bacterially derived GST-L1 fusion proteins of HPV were assessed with multiplexed serology and HPV DNA was evaluated with PCR-based sequencing. Few subjects were dually positive to HPV DNA and serum antibodies for any HPV (6.6% of men and 3.1% of women). The proportion of men ever having been infected with any HPV (DNA and/or antibody positive) was higher than that of women (71.0% vs. 65.2%, P < 0.001). Type-specific association was observed for genital HPV infection and HPV seropositivity among women but not among men. A positive correlation between the number of lifetime sexual partners and positivity for oncogenic HPV DNA and/or antibodies was found in men but was absent in women. Among 762 couples, the presence of HPV DNA and/or antibodies in one partner was positively associated with the identical HPV type in the other partner. These findings may reflect a site-specific natural course of HPV infection and further understanding of the epidemiology of HPV.

How to best measure the effectiveness of male human papillomavirus vaccine programmes?

In many countries now, vaccination of young adolescent girls with prophylactic human papillomavirus (HPV) vaccines has been rolled out as a public health programme. In countries where coverage has been high, this has led to dramatic reductions in cervical high-grade precancerous lesions, as well as genital warts. A reduction in circulating vaccine-related HPV types has also been demonstrated. With the introduction of gender-neutral approaches incorporating universal vaccination of pre-adolescent boys in some countries, implementation of post-vaccine monitoring will be critical to evaluate the incremental impact of male vaccination. In contrast to cervical screening programmes, population-wide screening for HPV infection or related disease in males is not recommended; hence real-time monitoring of HPV vaccine effectiveness in males will require dedicated surveillance strategies. Monitoring the prevalence of circulating genital HPV types using a sentinel surveillance model could offer a good surrogate marker of early vaccine effectiveness in males. However, such an approach requires careful consideration of the most appropriate anatomical sites from which to collect specimens, the best sampling methods and the most sensitive assays to use. Additionally, in assessing an accurate measure of the impact of HPV vaccination in the male population, the effect of herd protection will need to be assessed, as most male programmes will commence in the setting of established female programmes. This poses an interesting epidemiological challenge.

Serodiagnosis for tumor viruses

The known human tumor viruses include the DNA viruses Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV), Merkel cell polyomavirus (MCPyV), human papillomavirus (HPV), and hepatitis B virus (BV). RNA tumor viruses include human T-cell lymphotrophic virus type 1 (HTLV-1) and hepatitis C virus (HCV). The serological identification of antigens/antibodies in serum is a rapidly progressing field with utility for both scientists and clinicians. Serology is useful for conducting seroepidemiology studies and to inform on the pathogenesis and host immune response to a particular viral agent. Clinically, serology is useful for diagnosing current or past infection and for aiding in clinical management decisions. Serology is useful for screening blood donations for infectious agents and for monitoring the outcome of vaccination against these viruses. Serodiagnosis of human tumor viruses has improved in recent years with increased specificity and sensitivity of the assays, as well as reductions in cost and the ability to assess multiple antibody/antigens in single assays. Serodiagnosis of tumor viruses plays an important role in our understanding of the prevalence and transmission of these viruses and ultimately in the ability to develop treatments/preventions for these globally important diseases.

Natural history of high-grade cervical intraepithelial neoplasia: a review of prognostic biomarkers

The natural history of high-grade cervical intraepithelial neoplasia (CIN) is largely unpredictable and current histopathological examination is unable to differentiate between lesions that will regress and those that will not. Therefore, most high-grade lesions are currently treated by surgical excision, leading to overtreatment and unnecessary complications. Prognostic biomarkers may differentiate between lesions that will regress and those that will not, making individualized treatment of high-grade CIN possible. This review identifies several promising prognostic biomarkers. These biomarkers include viral genotype and viral DNA methylation (viral factors), human leukocyte antigen-subtypes, markers of lymphoproliferative response, telomerase amplification and human papillomavirus-induced epigenetic effects (host factors) and Ki-67, p53 and pRb (cellular factors). All identified biomarkers were evaluated according to their role in the natural history of high-grade CIN and according to established criteria for evaluation of biomarkers (prospective-specimen-collection, retrospective-blinded-evaluation [PROBE] criteria). None of the biomarkers meets the PROBE criteria for clinical applicability and more research on prognostic biomarkers in high-grade CIN is necessary.

Detection of immunoglobulin IgA and IgG against human papilloma virus

The interest in human papilloma virus (HPV) seropositivity has increased considerably since HPV vaccines have become available worldwide. The aim of this study was to assess the performance of enzyme-linked immunosorbent assay (ELISA) in analyzing serum samples provided from women with and without genital DNA-HPV infection confirmed by polymerase chain reaction (PCR), for detection of specific antibodies of the isotypes IgG and IgA recognizing HPV-16 and -18, as well as virus-like particles (VLPs). From August to December 2013, 50 sexually active female patients between 18 and 35 years of age from the outpatient clinic at the university hospital were enrolled. In order to test them, positive controls were obtained from patients with HPV-induced lesions and who were DNA-HPV positive confirmed by PCR. A specific assay was used to identify antibodies to HPV VLPs by ELISA. The samples were divided into HPV positive and negative, and an ELISA detecting IgA and IgG anti-HPV-VLP was carried out. The effectiveness of ELISA and the kappa (k) index was obtained from the values entered in the receiver operating characteristic (ROC) curves for IgG and IgA. IgG-VLP-HPV-16 showed a good correlation between ELISA and PCR (k=0.75), and IgG-VLP-HPV-18 showed a very good correlation between ELISA and PCR (k=0.84). While the IgA antibody correlation was also positive, although weaker, IgA-VLP-HPV-16 was moderate (k=0.45) and IgA-VLP-HPV-18 good (k=0.66). The efficacy of the assay concerning IgG was: sensitivity, specificity, and accuracy were 82.3%, 92%, and 88% to IgG-VLP-HPV-16, and 100%, 92%, and 94% to IgG-VLP-HPV-18. The assay concerning IgA was: sensitivity, specificity, and accuracy were 64.7%, 80%, and 73.8% to IgA-VLP-HPV-16, and 100%, 80%, and 84.8% to IgA-VLP-HPV-18. IgG and IgA antibodies against HPV-16 and -18 can be detected in unvaccinated individuals by using the VLP that serve as the basis for bivalent HPV vaccine. The values for ELISA assays and the values found for IgG correlate good/very good with HPV-16/18 detected by PCR.

HPV seroconversion following anal and penile HPV infection in HIV-negative and HIV-infected MSM

BACKGROUND

We assessed human papillomavirus (HPV) seroconversion following anal and penile HPV infection in HIV-negative and HIV-infected men who have sex with men (MSM).

METHODS

MSM aged ≥18 years were recruited in Amsterdam, the Netherlands (2010-2011), and followed up semiannually. Antibodies against 7 high-risk HPV types in baseline and 12-month serum samples were tested using a multiplex immunoassay. Baseline, 6-, and 12-month anal and penile samples were tested for HPV DNA using the SPF10-PCR DEIA/LiPA25 system. Statistical analyses were performed using logistic regression with generalized estimating equations.

RESULTS

Of 644 MSM included in the analysis, 245 (38%) were HIV-infected. Median age was 38 years for HIV-negative and 47 years for HIV-infected MSM (P < 0.001). Seroconversion against ≥1 of the 7 HPV types was observed in 74 of 396 (19%) HIV-negative and 52 of 223 (23%) HIV-infected MSM at risk (P = 0.2). Incident [adjusted OR (aOR) 2.0; 95% confidence interval (CI), 1.1-3.4] and persistent (aOR 3.7; 95% CI, 1.5-9.5) anal HPV infections were independently associated with type-specific seroconversion in HIV-negative MSM. In HIV-infected MSM, there was a nonsignificant positive association between penile HPV infection at any time point and seroconversion (aOR 1.7; 95% CI, 0.9-3.2).

CONCLUSIONS

Incident or persistent anal HPV infection was an independent determinant of seroconversion in HIV-negative MSM.

IMPACT

Our data support that seroresponse may vary per anatomic site and that persistent HPV infections are more likely to elicit a detectable humoral immune response.

Seroepidemiology of high-risk HPV in HIV-negative and HIV-infected MSM: the H2M study

BACKGROUND

Men who have sex with men (MSM), in particular HIV-infected MSM, are at increased risk for diseases related to human papilloma virus (HPV). Our goal was to assess the effect of HIV status on the presence of type-specific antibodies against seven high-risk HPV types in HPV-unvaccinated MSM. Moreover, we compared determinants of HPV seropositivity between HIV-negative and HIV-infected MSM.

METHODS

MSM ≥18 years of age were recruited from the Amsterdam Cohort Studies, a sexually transmitted infection clinic, and an HIV-treatment center in Amsterdam, the Netherlands. Participants completed a risk-factor questionnaire; serum samples were analyzed using a fluorescent bead-based multiplex assay.

RESULTS

MSM (n = 795) were recruited in 2010 to 2011; 758 MSM were included in this analysis. Median age was 40.1 years (interquartile range 34.8-47.5) and 308 MSM (40.6%) were HIV-infected. Seroprevalence of HPV-16 was 37.1% in HIV-negative and 62.7% in HIV-infected MSM (P < 0.001); seroprevalence of HPV-18 was 29.1% in HIV-negative MSM and 42.5% in HIV-infected MSM (P < 0.001). Similar patterns of seroprevalence were observed for HPV types 31, 33, 45, 52, and 58. In multivariable analyses, HPV seropositivity was associated with HIV infection [adjusted OR = 2.1; 95% confidence interval, 1.6-2.6]. In multivariable analyses stratified by HIV status, increasing age and number of lifetime male sex partners were significantly associated with HPV seropositivity in HIV-negative, but not HIV-infected MSM.

CONCLUSIONS

Seroprevalence of high-risk HPV types is high among unvaccinated MSM.

IMPACT

HIV infection is a strong and independent determinant for HPV seropositivity, which we hypothesize is because of increased persistence of HPV infection in HIV-infected MSM.

Treatment failure in patients with HPV 16-induced vulvar intraepithelial neoplasia: understanding different clinical responses to immunotherapy

Failure of the immune system to launch a strong and effective immune response to high-risk HPV is related to viral persistence and the development of anogenital (pre)malignant lesions such as vulvar intraepithelial neoplasia (VIN). Different forms of immunotherapy, aimed at overcoming the inertia of the immune system, have been developed and met with clinical success. Unfortunately these, in principal successful, therapeutic approaches also fail to induce clinical responses in a substantial number of cases. In this review, the authors summarize the traits of the immune response to HPV in healthy individuals and in patients with HPV-induced neoplasia. The potential mechanisms involved in the escape of HPV-induced lesions from the immune system indicate gaps in our knowledge. Finally, the interaction between the immune system and VIN is discussed with a special focus on the different forms of immunotherapy applied to treat VIN and the potential causes of therapy failure. The authors conclude that there are a number of pre-existing conditions that determine the patients' responsiveness to immunotherapy. An immunotherapeutic strategy in which different aspects of immune failure are attacked by complementary approaches, will improve the clinical response rate.

Do neutralizing antibody responses generated by human papillomavirus infections favor a better outcome of low-grade cervical lesions?

To determine the role of neutralizing antibody generated by human papillomavirus (HPV) infections, baseline levels of serum neutralizing antibodies directed against HPV 16 and cervical HPV DNA were determined in 242 unvaccinated women with low-grade cervical abnormalities, who were then monitored by cytology and colposcopy every 4 months. In women infected with HPV 16 (n = 42), abnormal cytology persisted longer in those positive for HPV 16-specific neutralizing antibodies at baseline (median time to cytological regression: 23.8 vs. 7.2 months). Progression to cervical precancer (cervical intraepithelial neoplasia grade 3) within 5 years occurred only among women carrying HPV 16-specific neutralizing antibodies (P = 0.03, log-rank test). In women infected with types other than HPV 16 (n = 200), detection of HPV 16-specific neutralizing antibodies was not correlated with disease outcome. In conclusion, development of specific neutralizing antibodies following natural HPV 16 infection did not favor a better outcome of low-grade cervical lesions induced by HPV 16 or by other types; rather, detection of neutralizing antibodies generated by current infection may reflect viral persistence and thus help identify those who are at high risk of disease progression.

Age-specific human papillomavirus antibody and deoxyribonucleic acid prevalence: a global review

PURPOSE

Global data on human papillomavirus (HPV) serological and deoxyribonucleic acid (DNA) prevalence are essential to optimize HPV prophylactic vaccination strategies.

METHODS

We conducted a global review of age-specific HPV antibody and studies with both antibody and DNA prevalence for HPV-16, -18, -6, and -11.

RESULTS

One hundred seventeen studies were included; participants' ages ranged from several hours to >90 years. HPV-16 seroprevalence was generally higher in Africa, Central and South America, and North America, more prevalent among women than among men, and peaked around ages 25-40 years. HPV-18 seroprevalence was generally lower than HPV-16 with a later age peak. Data were limited for HPV-6 and -11, both of which peaked at ages similar to HPV-18. Among 9-26-year-old females, HPV-16 seroprevalence ranged from 0%-31% in North America, 21%-30% in Africa, 0%-23% in Asia/Australia, 0%-33% in Europe, and 13%-43% in Central and South America. HPV-16/-18 DNA prevalence peaked 10-15 years before corresponding HPV-16/-18 antibody prevalence.

CONCLUSIONS

Females within the HPV vaccine-eligible age-group (9-26 years) had a range of dual HPV-16 DNA and serology negativity from 81%-87%, whereas 90%-98% were HPV-16 DNA negative. Serology and DNA data are lacking worldwide for females younger than age 15 years, the prime target group for vaccination.

Serum antibody response following genital {alpha}9 human papillomavirus infection in young men

Background. Although the prevalence of human papillomavirus (HPV) genital infection is similarly high in males and females, seroprevalence is lower in males. This study assessed rates and determinants of seroconversion after detection of genital HPV infection in young men. Methods. We investigated HPV type-specific seroconversion in a cohort of heterosexual male university students who had an α9 HPV type (HPV-16, -31, -33, -35, -52, -58, or -67) detected in the genital tract (n = 156). HPV DNA and antibodies were detected and typed using liquid bead-based multiplex assays. We calculated seroconversion using Kaplan-Meier survival analysis. Cox proportional hazards models with generalized estimating equations were used to examine associations with seroconversion. Results. Within 24 months of detecting genital HPV infection, type-specific seroconversion ranged from 4% for HPV-52 to 36% for HPV-31. HPV-16 seroconversion at 24 months was 13% (95% confidence interval [CI], 7%-25%). Among incident HPV infections, ever cigarette smoking and infection site(s) (shaft/scrotum and glans/urine vs shaft/scrotum or glans/urine only) were positively associated with type-specific seroconversion. Conclusions. For each of the α9 HPV types, type-specific seroconversion within 24 months was observed in 36% or less of infected men. Seroconversion might be related to cigarette smoking and genital site(s) infected.

Lack of type-specific concordance between human papillomavirus (HPV) serology and HPV DNA detection in the uterine cervix and oral mucosa

There is limited knowledge about longitudinal genotype-specific concordance between human papillomavirus (HPV) serology and co-existent presence of HPV DNA in the uterine cervix. The role of oral HPV infections in inducing serological response is unclear, as is the effect of HPV antibodies on the outcome of oral HPV infections. The present study is part of the Finnish Family HPV Study designed to evaluate dynamics of HPV infections within families. Here, we correlated the point prevalence of HPV6, 11, 16, 18 and 45 antibodies and concomitant genotype-specific HPV DNA detection in cervical and oral samples of 323 mothers during their 3 year (mean 37.5 months) follow-up. The mean age of these pregnant mothers at enrolment (third trimester) was 25.5 years. HPV antibodies were analysed with multiplex HPV serology and HPV genotyping was performed using a Multimetrix kit (Progen Biotechnik). There was no concordance between cervical DNA detection and co-existent seropositivity, and the same was true even in samples taken 12 months apart. Women who cleared their cervical HPV16 infection had the highest HPV16 antibody levels, whereas those who acquired incident HPV16 infections had the lowest antibody levels. Neither the presence nor the dynamics of oral HPV DNA had any correlation with HPV serology.

Modelling patterns of clearance of HPV-16 infection and vaccination efficacy

A model representing carcinogenic HPV infection transmission dynamics and cervical cancer natural history was adapted to assess the consequences of introducing vaccination against HPV-16 infection. Alternative scenarios either allowing repeated infections with the HPV-16 (i.e. SIS scenario) or assuming that clearance of infection occurs through the development of a long lasting, specific immune response which protects against re-infection (i.e. SIR scenario) were investigated. The difference in reduction in lifetime cervical cancer achieved through vaccination of 12-year-old girls, between SIS and SIR scenarios, was up to 25% of expected cases in an unscreened population. This difference increased to 30% when vaccination of 12-year-old boys was also included as an intervention. The role of SIS or SIR dynamics should be accounted for in the assessment of model-based projections of the effectiveness of vaccination programmes, until available data about the transmission dynamics support the accuracy of model predictions.

High-throughput profiling of the humoral immune responses against thirteen human papillomavirus types by proteome microarrays

We have developed microarrays with all eight proteins encoded by 13 different human papillomavirus types associated with anogenital cancer (HPV-16, -18, -31, -33, -35, -45, and -53), genital warts (HPV-6 and -11), or skin lesions (HPV-1, -2, -4, and -5). We analyzed the seroprevalence of antibodies in 546 patients, which had either cervical carcinomas, or precursor lesions, or which were asymptomatic. All patient groups contained sera ranging from high reactivity against multiple HPV proteins to low or no reactivity. Computational analyses showed the E7 proteins of carcinogenic HPV types as significantly more reactive in cancer patients compared to asymptomatic individuals and discriminating between cancer and HSIL or LSIL patients. Antibodies against E4 and E5 had the highest seroprevalence but did not exhibit differential reactivity relative to pathology. Our study introduces a new approach to future evaluation of the overall antigenicity of HPV proteins and cross-reaction between homologous proteins.

Human papillomavirus 16 and 18 L1 serology in Korean women with high-grade cervical intraepithelial neoplasia and cervical cancer

We aimed to determine the prevalence of HPV-16/18 antibodies in Korean women with high-grade cervical intraepithelial neoplasia (CIN) and cervical cancer. We conducted the hospital-based case-control study at the university hospital between 2003 and 2006. Cases were 130 high-grade CIN and 43 cervical cancer patients and the control group was 106 women showing normal cervical cytology. Enzyme-linked immunosorbent assays were performed for HPV-16/18 L1 virus-like particles (VLPs) as an antigen. Seropositivity for HPV-16 VLP and HPV-18 VLP was found in 67.4% and 30.2% of cancer patients and 59.2% and 20.0% of high-grade CIN patients, respectively. Seropositivity for HPV-16 with high-grade CIN (OR 6.91; 95% CI 3.74-12.76) and cervical cancer (OR 8.99; 95% CI 3.88-20.84) presented significant associations, as did seropositivity for HPV-18 (high-grade CIN: OR 3.64; 95% CI 1.67-7.95, cervical cancer: OR 6.82; 95% CI 2.52-18.45). Patients with both HPV-16 and 18 seropositivity were 9.38 times (95% CI 2.98-29.51) more likely to have high-grade CIN and 17.05 times (95% CI 4.55-63.87) more likely to have cancer. Both HPV 16 and 18 L1 VLP serology is the clear disease predictors of presence of high-grade CIN and cervical cancer.

Specificity of L1 peptides versus virus-like particles for detection of human papillomavirus-positive cervical lesions in females attending Engativa Hospital, Bogota, Colombia

A serological test for the detection of human papillomavirus (HPV) infection in females at risk of developing cervical cancer could be based on conserved L1 peptides with low levels of antigenicity specifically recognized by antibodies from patients with cervical lesions infected with high-risk HPV (HR-HPV) types. The aim was to assess the ability of L1 peptides 18283, 18294, and 18301 compared with the ability of virus-like particles (VLPs) to identify these infections in females. A total of 391 HPV-infected female volunteers were interviewed, and peripheral blood and cervical cells were obtained for detection of anti-HPV antibodies and HPV DNA; all of the patients had a Pap smear test; 287 patients were referred for colposcopy or biopsy, according to gynecological criteria. The level of agreement, as determined by the use of the Lin coefficient (rho value), showed that 75 to 83% of females with HR-HPV DNA-positive cervical lesions had antibodies that recognized VLPs and peptide 18283, 18294, or 18301, while 15 to 23% of the HPV DNA-negative females with a normal cytology had antibodies that recognized these three peptides and 45% had antibodies that recognized VLPs. The rate of agreement between peptides and VLPs for antibody detection was higher for patients with HPV DNA-positive cervical lesions. Peptides 18283, 18294, and 18301 showed similar sensitivities for the detection of HR-HPV DNA-positive cervical lesions and were more specific than VLPs. Peptide 18301 might be detecting protective antibodies in HPV DNA-negative females with atypical squamous cells of undetermined significance. These peptides could be useful for the design of a serology test for the detection of HR-HPV infection in females with cervical lesions and at risk of cervical cancer.

IgG antibodies to HPV16, 52, 58 and 6 L1-capsids and spontaneous regression of cervical intraepithelial neoplasia

To identify the predictive markers for spontaneous regression of cervical intraepithelial neoplasia (CIN), we examined whether IgG antibody responses to common human papillomavirus (HPV) L1-capsids correlate with CIN regression. In a cohort study, a total of 116 Japanese women with CIN grade I/II were tested for cervical HPV DNA and serum IgG antibodies to HPV16/52/58/6 L1-capsids. Our data suggest that baseline IgG reactivities to HPV L1-capsids do not serve as a predictive marker of CIN regression, in contrast to histological CIN grades and HPV DNA status.

Two L1-peptides are excellent tools for serological detection of HPV-associated cervical carcinoma lesions

A persistent high risk human papillomavirus (HR-HPV) infection causes cervical intraepithelial lesions and cervical carcinoma. There is evidence that detecting anti-L1 antibodies could be successfully used for discriminating between cervical lesion patients and women having normal cytology. It was found that peptides 18283 (55PNNNKILVPKVSGLQYRVFR74) and 18294 (284LYIKGSGSTANLASSNYFPT300) from the L1-surface exposed regions were specifically recognised by antibodies from the cervical lesion patient sera. These peptides were tested against 165 womens' normal cytology sera and 148 cervical lesion or cervical cancer patients' sera. Less than 3.6% of women's normal cytology sera recognised peptides 18283 or 18294; on the contrary, 91% to 96% of the cervical lesion (CIN I to CIN III) or cervical cancer patient sera recognised peptides 18283 and 18294. These data show that anti-peptide 18283 and 18294 antibodies in the patients' sera are strongly associated with the presence of HR-HPV associated cervical lesions, showing 92-97% sensitivity and 89-95% specificity in recognising precancerous and cervical cancer patients. These two peptides could be excellent tools for use in large-scale serological screening of women populations at risk of developing cervical carcinoma.

Gender differences in sexual biomarkers and behaviors associated with human papillomavirus-16, -18, and -33 seroprevalence

BACKGROUND

The elevated risk for incident head and neck cancer among human papillomavirus (HPV)-16-seropositive individuals has substantiated a role for HPV in the etiology of head and neck cancers. The relationship between HPV seroreactivity and prevalent oral HPV infection in men and women without cancer has yet to be investigated.

GOAL

The goal of this study was to evaluate a possible association between oral HPV infection and HPV seroreactivity after adjustment for gender, sexual behaviors, and sexually transmitted disease.

STUDY DESIGN

A cross-sectional study of factors associated with HPV-16, -18, and -33 seroreactivity was performed in a population of 586 men and women with and without HIV infection. Antibodies in sera were measured by use of a virus-like protein (VLP)-based enzyme-linked immunosorbent assay. Exfoliated cells from the tonsillar and oral mucosa were analyzed for the presence of 38 mucosal HPV types by polymerase chain reaction.

RESULTS

Women had significantly greater seroreactivity for all HPV types investigated when compared with men (odds ratio, 4.3; 95% confidence interval, 3.0-6.0). Seroprevalence was greatest in men and women aged 35 to 45 years. Tonsillar HPV infection, oral sex with men, and HIV infection were independently associated with HPV seroreactivity in men after adjustment for age and number of sexual partners. In women, HSV-2 seropositivity and a history of sexually transmitted diseases were similarly important. Oral and tonsillar HPV infection were not associated with HPV seroreactivity in women.

CONCLUSION

HPV seropositivity is associated with sexually transmitted diseases among women and possibly mucosal HPV exposures in men. Tonsillar HPV infection could impact seroprevalence, particularly in men.

Human papillomaviruses and cancer in Uganda

In a case-control study in Uganda, we examined associations between different cancer sites or types in relation to antibodies against human papillomaviruses (HPV)-16, -18 and -45. For each cancer site or type, the control group comprised all other cancers excluding those known, or thought to be associated with HPV infection (cancers of the uterine cervix, penis and eye). Among controls the seroprevalence of antibodies was 11% (68/616) against HPV-16, 5% (29/605) against HPV-18 and 6% (35/605) against HPV-45. Antibodies against HPV-16 were significantly associated with only two cancers: uterine cervix [prevalence of antibodies 27% (51/191); odds ratio (OR) 2.0, 95% confidence interval (CI) 1.2-3.1, P=0.01] and penis [prevalence of antibodies 27% (4/15); OR 6.4, 95% CI 1.7-24.3, P=0.01]. For both cancers, the risk increased with increasing anti-HPV-16 antibody titre (Ptrend=0.01 for each). No cancer site or type was significantly associated with antibodies against HPV-18 and -45.

Natural History of Human Papillomavirus Type 16 Virus-Like Particle Antibodies in Young Women

Immunization with a vaccine of human papillomavirus (HPV) type 16 virus-like particles (VLPs) can reduce incidence of HPV-16 infection and its related cervical intraepithelial neoplasia. However, development of detectable antibodies to VLPs does not always occur after natural HPV infection. This study examined prospectively for seroconversion and duration of antibodies to HPV-16 VLPs and their associated host and viral factors. Six-hundred eight subjects were tested for HPV DNA biannually and for IgG and IgA antibodies to HPV-16 VLPs annually for 3 years. Both IgG and IgA antibodies to HPV-16 VLPs were predominantly type specific. Women with cervicovaginal HPV-16 infection were 8-10 times more likely to seroconvert than those with infection of HPV-16-related types. Among subjects who had an incident infection with HPV-16, a maximum of 56.7% became seropositive for IgG within 8.3 months and 37.0% had IgA within 14 months. Detectable seroconversion was a slow process that required sufficient antigenic exposure associated with either a high viral load (relative risk = 5.7 for IgG) or persistent infection of HPV-16 (relative risk = 3.4 for IgA). The median duration for both types of antibodies was approximately 36 months. Antibodies could persist for a long period of time if the initial antibody levels were high or if there was continued antigenic exposure.

Mucosal IgG and IgA responses to human papillomavirus type 16 capsid proteins in HPV16-infected women without visible pathology

Human papillomavirus type 16 (HPV16) may infect the cervical epithelium without producing pathological changes for a long time. To investigate if mucosal antibodies are induced in HPV16-infected women without visible pathology, cervical mucus from HPV16-infected patients with and without evident pathology, along with mucus from uninfected women were analyzed for the presence of mucosal IgG and secretory IgA (sIgA) antibodies to HPV16 capsid proteins by ELISA. sIgA and IgG antibodies were found in a significantly higher proportion of infected patients compared with uninfected women (p < 0.0001). sIgA antibodies were present in 13.1% of infected patients without visible pathology, the proportion of positivity increased to 27.0% in patients with visible pathology (p = 0.001). Mucosal IgG response was observed in 6.5% of patients without and 27.5% of patients with visible pathology (p = 0.00005). The antibody mean signal strength was significantly higher in patients with than in patients without pathological evidence (p < 0.005). In conclusion, both sIgA and IgG are found in patients without pathological signs of infection, however, the response increases significantly in patients with pathological evidence, suggesting that the appearance of these changes might be associated with a more vigorous antibody-mediated mucosal reaction.

The effects of avoidance on cytotoxic/suppressor T cells in women with cervical lesions

The purpose of this study was to examine the relationship between avoidant and intrusive ideation about cancer risk and immune responses among women with mild cervical dysplasia. Participants were 54 women undergoing diagnostic follow-up (i.e. colposcopy) for an abnormal Pap smear test result. Baseline assessments, collected prior to the colposcopy appointment, included demographic and medical history, levels of depression, and the intrusion and avoidance subscales of the Revised Impact of Events Scale. In addition, a sample of blood was obtained at baseline and 6-month follow-up for immune assessments. Hierarchical regression analyses revealed that higher levels of cognitive and behavioral avoidance at baseline predicted a significantly lower percentage of circulating cytotoxic/suppressor T cells (CD3(+)/CD8(+)) at 6-month follow-up, after controlling for baseline levels of cytotoxic/suppressor T cells and potential confounding variables (e.g. age, smoking status). Baseline intrusive ideation was unrelated to changes in percentage of cytotoxic/suppressor T cells. Avoidant ideation, but not intrusive ideation or depression, appears to be associated with alterations in immunologic measures in women with cervical lesions. The findings suggest that it may be important to evaluate the impact of cognitive and behavioral avoidance on progression of precancerous cervical lesions.

Characterization of IgA response among women with incident HPV 16 infection

Previous studies have characterized the prevalence and duration of serum IgG antibodies to human papillomavirus type 16 (HPV 16) in a well-studied cohort of college women, using viruslike particle- (VLP) based ELISAs. In this study IgA antibodies in cervical secretions and sera were examined using a newly developed capsomer-based ELISA and the patterns observed for serum IgG, serum IgA, and cervical IgA antibodies were compared. The median time to antibody detection from the first detection of HPV 16 DNA was 10.5 months for IgA in cervical secretions and 19.1 months for serum IgA. Serum IgA antibody conversion was observed less frequently and occurred later than IgA conversion in cervical secretions (P = 0.011) or serum IgG conversion (P = 0.051). The median time to antibody reversion, following seroconversion, was 12.0 months for IgA in cervical secretions and 13.6 months for serum IgA, whereas approximately 20% of women with serum IgG antibodies reverted within 36 months. Thus, the duration of IgA in cervical secretions and sera was shorter than the duration of serum IgG (P = 0.007 and 0.001).

Enhanced immune response to DNA-based HPV16L1 vaccination by costimulatory molecule B7-2

We have investigated whether co-injection of DNA encoding the costimulatory molecule B7-2 augments immune response to the major capsid protein L1 of the high-risk human papillomavirus type 16 (HPV16L1). While immunoglobulin G (IgG) specific to HPV16L1 was detected in sera from mice injected intramuscularly with pcDNA-L1 that encodes HPV16L1, a significantly increased level of IgG was found in sera from mice immunised with pcDNA-L1 in conjunction with pLXHDmB7-2 DNA. Levels of IgG in the anti-sera were correlated with the inhibitory activity of the murine erythrocyte hemagglutination caused by the virus-like particles (VLP) and the binding of VLP to HeLa cells. Moreover, splenic cells isolated from mice co-injected with pLXHDmB7-2 had stronger proliferation and more IFN-gamma producing T cells (CD4(+) and CD8(+)) when stimulated with HPV16 VLP compared with cells from mice that had received pcDNA-L1 alone and mice of the control groups. Furthermore, in footpad swelling test, mice co-immunised with pLXHDmB7-2 had greater skin thickness over those immunised with pcDNA-L1 alone or control mice. We conclude that co-injection of DNA encoding B7-2 can enhance both humoral and cellular immune responses elicited by DNA-based vaccination against HPV16 infection in mice.

Prospective study on cervical neoplasia: presence of HPV DNA in cytological smears precedes the development of cervical neoplastic lesions

OBJECTIVES

The principal aim of the study was to verify whether HPV infection in healthy women, as determined by HPV DNA detection, was associated with an increased risk of development of cervical lesions.

METHODS

Cervical smears collected at enrolment into the prospective study conducted in Prague during 1975-83 were tested for the presence of HPV DNA by means of a polymerase chain reaction (PCR) using the general GP5/6 primers and a mixture of primers specific for the E6 gene. 120 smears from patients in whom cervical neoplasia had been detected in the course of the prospective study and 208 smears from control women who had remained healthy throughout the observation period were analysed. Patients and controls were matched by age, number of sexual partners, age at first intercourse, and smoking habit. Patients were divided into three groups, A, B, and C, according to their cytological, colposcopic, and histological findings at enrolment. Group A consisted of 67 women found ill at enrolment, group B of 26 women with slightly suspicious findings, while group C comprised 27 women with normal findings at enrolment. In addition, sera taken at enrolment from these patients and controls were tested for the presence of antibodies reactive with virus-like particles (VLPs) of HPV 16, 18, and 33.

RESULTS

For the whole cohort, there was a statistically highly significant difference in the presence of HPV DNA between patients and controls. Furthermore, the difference in the presence of HPV DNA between patients and controls was highly significant not only in those who had been found ill at enrolment (group A) but, most importantly, also in women who had developed the disease in the course of the follow up (groups B and C). Women positive for HPV DNA possessed HPV antibodies to VLP16, 18 and 33 significantly more often than those who were free of HPV DNA.

CONCLUSION

This indicated that healthy women who were positive for HPV DNA at enrolment were at an increased risk of developing cervical neoplasia (OR = 18.5; CI 5.9 to 57.6).

Mucosal immunoglobulin-A and -G responses to oncogenic human papilloma virus capsids

Oncogenic human papilloma virus (HPV) infection is the most important risk factor for developing cervical cancer. It is known that serum antibody responses against these viruses are associated with persistent infection. We conducted an epidemiological study of 627 women to detect cervical mucosal immunoglobulin (Ig)A and IgG responses to oncogenic HPV capsids. Antibody reactivity and cervical HPV infection genotypes were examined by enzyme-linked immunosorbent assay (ELISA) using HPV types 16, 18, 31, and 45 virus-like particles, and a polymerase chain reaction-based method, respectively. HPV infection was defined as being positive for HPV DNA. Multivariate analysis revealed that a mucosal IgA response was associated with the HPV infection, whereas the IgG response was associated with high-grade cervical squamous intraepithelial lesions (SIL)/squamous cell cancer (SCC) and subject age (40-49 years). IgA was positive in 72% of women with oncogenic HPV infections, whereas IgG was positive in 64% of women with high-grade SIL/SCC. The longitudinal study demonstrated that the IgA response was elicited earlier than the IgG response, and the IgG response was barely induced in the preclinical HPV infection. However, once an IgG response was induced, it persisted longer after HPV clearance. The mucosal IgA response reflects current HPV infection, whereas an IgG response may be induced with the development of cervical lesions.

Antibodies to human papillomavirus 16 L1 virus-like particles as an independent prognostic marker in cervical cancer

OBJECTIVE

Infection with high-risk human papillomavirus (HPV) types such as HPV-16 is a major risk factor for the development of cervical cancer. HPV-16 capsid antibodies are detectable in approximately 50% of patients with HPV-16 DNA-positive cervical cancer. We investigated the prognostic significance of HPV capsid antibodies for survival in patients with cervical cancer in comparison with conventional clinicopathologic features such as staging, histologic grading, histology, age, and treatment modality.

STUDY DESIGN

Serum samples from 68 patients with cervical cancer and 65 healthy female control subjects were analyzed by enzyme-linked immunosorbent assay for HPV-specific immunoglobulin G (IgG) antibodies to baculovirus expressed HPV-6, HPV-11, HPV-16, and HPV-18 L1 virus-like particles (VLPs).

RESULTS

HPV-16 L1 IgG antibodies were detectable in 6 of 65 (9%) of the control subjects and in 19 of 68 (28%) of the patients with cervical cancer (P =.007). In the subgroup of patients with HPV-16 DNA-positive cervical cancer (comprising 50% of the investigated samples), HPV-16 L1 antibodies were detected in 40%. HPV-16 L1 seropositivity was in univariate and multivariate analysis in addition to International Federation of Gynecology and Obstetrics stage, the only independent positive prognostic factor for overall survival (P =.01).

CONCLUSION

Antibodies to HPV-16 L1 were found to be an independent prognostic factor for overall survival in patients with cervical cancer. Thus, HPV-16 infection may be involved not only in oncogenesis but also in tumor development and behavior.

Detection of neutralizing antibodies against human papillomaviruses (HPV) by inhibition of gene transfer mediated by HPV pseudovirions

The goal of this study was to develop a human papillomavirus (HPV) neutralization assay using HPV pseudovirions generated in vitro. For this purpose, gene transfer efficiency of HPV virus-like particles (VLPs) was improved by using direct interaction between a reporter plasmid and the VLPs. Electron microscopic observation of the interaction between DNA molecules and VLPs revealed that VLPs always interact with a single DNA molecule and that VLPs bind to the end of linearized DNA molecules. An 100-fold improvement in the gene transfer was obtained by simple interaction between a linearized DNA molecule and VLPs. Moreover, direct interaction methods offer the possibility of transferring plasmids a size higher than that of the papillomavirus genome. The approach that we developed to generate HPV-16 and HPV-31 pseudovirions proved to be suitable for testing neutralizing antibodies in human sera both after immunization and after natural infection.

Serologic response to human oncogenic papillomavirus types 16, 18, 31, 33, 39, 58 and 59 virus-like particles in colombian women with invasive cervical cancer

The serologic response against virus-like particles (VLP) from 7 high risk genital papillomaviruses was investigated by ELISA in 147 Colombian women with invasive cervical cancer and 147 age-matched cytologically normal and HPV-DNA negative women. Anti-VLP antibodies were detected in 82% of the invasive cervical cancer patients and in 56% of the controls. Detection of antibodies against multiple HPV types is the rule and the presence of high antibody titers was associated with higher survival of cancer patients. Higher anti-VLP seroprevalence was observed in younger cancer patients. In those followed serologically for 1 year, antibodies generally remained at the same level. However, in some patients an increase or decrease in antibody levels occurred simultaneously for multiple HPV types, suggesting cross-reactivity between the HPV types investigated. Investigation of seroreactivity between 8 high risk HPVs suggested that there is some cross-reactivity between phylogeneticaly-related types such as 16, 31, 33 and 58; and 18, 45 and 59. In conclusion, our results confirmed (i) the high rate of HPV infections in Colombia, both in patients with cervical cancer and in the general population, and the particularly high rate of infections due to HPV 31 and 58; and (ii) the validity of anti-VLPs as a marker of present or past HPV infection. The simultaneous appearance or disappearance of antibodies against multiple HPV VLPs suggests that the antibodies detected by ELISA are not always type specific.

Human T cell responses to HPV 16 E2 generated with monocyte-derived dendritic cells

Persistent infection with human papillomavirus (HPV) type 16 has been implicated in the etiology of cervical cancer. The E2 protein is required early in viral infection and therefore may serve as a useful immune target for a vaccine aimed at prevention or therapy of premalignant lesions. Dendritic cells (DC) prepared from monocytes and pulsed with bacterially produced HPV 16 E2 C-terminus protein were used to stimulate autologous T cells over several rounds of stimulation. T cells were tested for gamma-interferon release by ELISPOT and for cytotoxic activity by (51)chromium release assays. To generate E2-expressing target cells for cytotoxicity assays, we constructed a recombinant vaccinia virus encoding HPV 16 E2, which was used to infect autologous Epstein-Barr virus-transformed lymphoblastoid cell lines (LCL). The results show that DC pulsed with E2 C-terminus protein induce gamma-interferon-releasing T cells as demonstrated by ELISPOT. Furthermore, we demonstrate E2-specific lysis of vaccinia-E2 infected autologous LCL by CD8+ cytotoxic T lymphocytes (CTL). E2-specific CTL did not lyse untreated autologous LCL or LCL infected with wild-type vaccinia and showed low levels of cytotoxicity against natural killer cell-sensitive K562 cells. In addition, T cells stimulated with DC in the absence of E2 failed to demonstrate lysis of vaccinia-E2-labeled targets. Phenotypically, CTL populations were CD3+/CD8+. These results will facilitate the study of naturally occurring T-cell responses to HPV E2 in patients with cervical intraepithelial neoplasia and the development of immunotherapeutic strategies designed to treat this and other HPV-associated diseases.

Prevalence of anti-human papillomavirus type 16, 18, 31, and 58 virus-like particles in women in the general population and in prostitutes

Genital human papillomavirus (HPV) infection is sexually transmitted. The aim of the study was to characterize serological responses to HPV types 16, 18, 31, and 58 by exploring type-specific virus-like particles (VLPs) in two groups of women with very distinct sexual behaviors. Anti-VLP antibodies for types 16, 18, 31, and 58 and HPV DNA in cervical cells were investigated with 177 prostitutes and 283 age-matched controls from the female general population in Spain. Anti-VLP positivity increased with number of lifetime sexual partners in women from the general population, and no seroresponse was found in virgins. However, in prostitutes HPV infection was characterized by higher multireactivity to three or four VLPs (25%) than the general population (3%) and by a more frequent antibody response to HPV-58 than in the general population. About 75% of the women seropositive for type 58 had been born in a Latin American country. Seroprevalence of HPV and cervical HPV DNA in prostitutes were 14 and 10 times higher than observed in women in the general population (prevalence odds ratio [POR] of HPV seropositivity, 14.04 [95%; CI = 8.4 to 23.6] and POR for HPV DNA, 10.4 [95% CI = 3.9 to 27.6). Our results indicate that prostitutes are at an increased risk of oncogenic HPV infections, and they confirm the validity of anti-VLPs as markers of present or past HPV infection, that the number of sexual partners is the major determinant in acquisition of oncogenic HPV, and that anti-VLPs could be used as a marker of repeated infection in prostitutes.

Human papillomavirus infection, risk for subsequent development of cervical neoplasia and associated population attributable fraction

BACKGROUND

Human papillomavirus (HPV) is the major cause of cervical neoplasia but estimates of the population attributable fraction (PAR%), of HPV vary. PAR% has not been derived from longitudinal studies although assessment of HPV exposure prior to the neoplasia diagnosis should increase validity of such estimates.

AIMS

Systematic review and meta-analysis of longitudinal studies on HPV associated relative risk (RR) for and PAR% of HPV16 in cervical neoplasia.

METHODS

Pertinent data from longitudinal studies was made available through Medline and substituted by various hand searches. HPV associated weighted mean RR, with 95% confidence interval (CI) of cervical neoplasia, and the PAR% of HPV16 in cervical carcinoma were estimated both for unselected and low HPV prevalence populations.

RESULTS

HPV associated RR of cervical carcinoma in PCR-based studies was 17 (95% CI 8.2-33). HPV16 associated RRs in seroepidemiological studies were 3.3 (95% CI 2.2-4.9) for the unselected population, HPV16 seroprevalence 11.0%, and 12.5 (95% CI 5.5-29) for a population with low HPV16 seroprevalence of 5.3%. Corresponding PAR% estimates of HPV16 were 27 and 44%, respectively.

CONCLUSION

Protective vaccination against HPV16 infection would prevent up to 44% of cervical carcinoma.

Cervical secretory immunoglobulin A to human papillomavirus type 16 (HPV16) from HPV16-infected women inhibit HPV16 virus-like particles-induced hemagglutination of mouse red blood cells

Secretory immunoglobulin A (sIgA) antibodies are the first line of defence at the genital mucosa, and are thought to hinder viral infections by binding to conformational epitopes on the viral capsid. To investigate if cervical sIgA binds to conformational epitopes of the Human papillomavirus type 16 (HPV16), cervical mucus samples from 109 HPV16-infected patients were examined in a HPV16 virus-like particles-induced hemagglutination inhibition assay. 48 (44.1%) patients were able to inhibit hemagglutination. Inhibition of hemagglutination was associated with the presence of sIgA (P=0.001). In conclusion, naturally occurring cervical anti-HPV16 sIgA binds to and hinders conformational epitopes on the viral capsid, suggesting that these antibodies might have a neutralizing capacity.

Natural HPV immunity and vaccination strategies

BACKGROUND

the task of preventing premature death in women may be delivered by vaccinating against the high-risk papillomaviruses associated with various malignancies.

OBJECTIVES

we will discuss the immune mechanisms likely to be relevant to the control of an HPV infection in the cervix and assess the limited evidence for such immune recognition in the natural history of infection.

CONCLUSION

the next generation of vaccination strategies should include the use of HPV 16 early (E2 and/or E6 and/or E7) and late gene targets (L1 and L2) expressed as VLPs with their clinical and immunological evaluation aimed at therapy as well as prophylaxis. Important clinical efficacy assessment may be deliverable in relatively short-term studies by targeting patients with HPV 16 associated vulval intraepithelial neoplasia.

Longitudinal follow-up of antibody response to selected antigens of human papillomaviruses and herpesviruses in patients with invasive cervical carcinoma

A group of 21 cervical-carcinoma patients was followed longitudinally. All patients had undergone intensive radiotherapy. In the course of a more than 5-year observation period, 2 patients died of cervical cancer, 1 from other causes, 3 were lost from follow-up, and 15 survived without any signs of the disease. Sera taken before, up to 17 months after and more than 5 years after the start of therapy, were tested by ELISA for IgG antibodies reactive with a broad spectrum of HPV-derived antigens, glycoprotein G of HSV 2, whole virion antigen of HCMV, and a synthetic peptide corresponding to the immuno-dominant region of EBNA 1. The therapy was associated with a marked decrease in E2 and E7 antibodies in nearly all patients possessing pre-existing antibodies; the changes in VLP antibody levels in the treated women were more rare and less pronounced. In the course of the observation period, seroconversion to gG HSV2 positivity was seen in 5 patients, while, a marked increase in pre-existing gG HSV2 antibodies was observed in 5 out of 7 originally seropositive patients. At enrollment, only 2 patients were free of HCMV antibody and only 1 was free of EBNA1 antibody; no seroconversion relative to either antigen was seen during the observation period.

Attack rates of human papillomavirus type 16 and cervical neoplasia in primiparous women and field trial designs for HPV16 vaccination

BACKGROUND

Identification of human papillomavirus type 16 (HPV16) as the major risk factor for cervical neoplasia, and mass production of DNA free HPV capsids have paved the way to preventive vaccination trials. Design of such trials requires reliable attack rate data.

OBJECTIVE

Determination of (1) HPV16 and (2) cervical neoplasia attack rates in primiparous women. Estimation of actuarial sample sizes for HPV16 vaccination phase IV trials.

DESIGN

A longitudinal cohort study.

METHODS

Population based Finnish Maternity Cohort (FMC) and Finnish Cancer Registry (FCR) were linked for the identification of two cohorts of primiparous women: (1) a random subsample of the FMC: 1656 women with two pregnancies between 1983-9 or 1990-6 and living in the Helsinki metropolitan area, and (2) all 72,791 primiparous women living in the same area during 1983-94. Attack rate for persistent HPV16 infection (1) was estimated in 1279 seronegative women by proportion of seroconversions between the first and the second pregnancy. Comparable 10 year cumulative incidence rate (CR) of cervical intraepithelial neoplasia grade III and cervical cancer (CIN III+) (2) was estimated based on cases registered at the FCR during 1991-4.

RESULTS

The HPV16 attack rates were 13.8% (< 18 years), 7.0% (18-19 years), 2.3% (21 years), 2.4% (23 years), and 4.5% (< 25 years). Number of vaccinees required for a 5 year efficacy trial with persistent HPV16 infection as the end point ranged between 1000 and 3900, assuming 80% power, 90%-70% vaccine efficacy (VE), and misclassification. The CRs of CIN III+ were 0.33% (< 18 years), 0.44% (18-19 years), 0.21% (20-24 years), and 0.28% (< 25 years). Number of vaccinees required for a 10 year efficacy trial with HPV16 positive CIN III+ as the end point was 15,000 assuming 80% power, 90% VE, and 75% aetiological fraction of CIN III+ for HPV16.

CONCLUSIONS

The attack rates of HPV16 and CIN III+ identify primiparous women under 25 years of age among target populations for postnatal HPV vaccination at phase II/III trials.