Distribution and viral load of type specific HPVs in different cervical lesions as detected by PCR-ELISA

Increased human papillomavirus viral load is correlated to higher severity of cervical disease and poorer clinical outcome: A systematic review

Cervical cancer is the fourth most common cancer in women worldwide and is caused by persistent infection with high-risk types of human papillomavirus (HPV). HPV viral load, the amount of HPV DNA in a sample, has been suggested to correlate with cervical disease severity, and with clinical outcome of cervical cancer. In this systematic review, we searched three databases (EMBASE, PubMed, Web of Science) to examine the current evidence on the association between HPV viral load in cervical samples and disease severity, as well as clinical outcome. After exclusion of articles not on HPV, cervical cancer, or containing clinical outcomes, 85 original studies involving 173 746 women were included. The vast majority (73/85 = 85.9%) reported that a higher viral load was correlated with higher disease severity or worse clinical outcome. Several studies reported either no correlation (3/85 = 3.5%), or the opposite correlation (9/85 = 10.6%); possible reasons being different categorization of HPV viral load levels, or the use of specific sampling methods. Despite variations in study design and populations, the above findings suggest that HPV viral load is correlated to clinical outcome, and may become an important biomarker for treatment selection and response monitoring for cervical cancer.

Unveiling diagnostic and therapeutic strategies for cervical cancer: biomarker discovery through proteomics approaches and exploring the role of cervical cancer stem cells

Cervical cancer (CC) is a major global health problem and leading cause of cancer deaths among women worldwide. Early detection through screening programs has reduced mortality; however, screening compliance remains low. Identifying non-invasive biomarkers through proteomics for diagnosis and monitoring response to treatment could improve patient outcomes. Here we review recent proteomics studies which have uncovered biomarkers and potential drug targets for CC. Additionally, we explore into the role of cervical cancer stem cells and their potential implications in driving CC progression and therapy resistance. Although challenges remain, proteomics has the potential to revolutionize the field of cervical cancer research and improve patient outcomes.

Verification of the association of the cycle threshold (Ct) values from HPV testing on Cobas4800 with the histologic grades of cervical lesions using data from two population-based cervical cancer screening trials

Objective

To verify the association of high-risk human papillomavirus (hrHPV) viral load reflected by cycle threshold (Ct) values from HPV testing on Cobas4800 assay with the histologic grades of cervical lesions via analysis on the combined data from two cervical cancer screening trials and to explore the referability of Ct values in management of the abnormalities from cervical cancer primary screening.

Methods

We analyzed the data from Chinese Multi-Center Screening Trial (CHMUST) and BUJI Cervical Cancer Screening Study Project (BUJI Study). All data to be analyzed in this paper were related to provider-collected samples. One-way ANOVA was performed to compare the Ct values among different histological groups, and Kendall’s tau-b correlation was applied to examine the association between Ct values and cervical lesion grades. The stepwise incidence of CIN2+ and CIN3+ in every 100 HPV positive individuals were calculated according to the descending of the genotype specific Ct values. The highest Ct values related to CIN3+ incidence rate 4% (or 25%) were used as the cutoffs to distinguish low-Ct value cases from the high-Ct value ones.

Results

A total of 1376 women in CHUMUST and BUJI Study who were aged 30–59 and positive of hrHPV for provider-collected samples on Cobas4800 with complete data in terms of the relevant Ct values (CtV) and the histological diagnosis were included for analysis. Our data showed significant difference among different histological grades of cervical lesions in the CtV of hrHPV, HPV16-plus (positive of HPV16 only or HPV16 plus 18 and/or pooled 12-HPV), and pooled 12-HPV (P < 0.05). No significant difference was found among different grades of lesions in term of correlated CtV of HPV18-plus (positive of HPV18 only or HPV18 plus pooled 12-HPV) (P > 0.05). The CIN2+ or CIN3+ incidence per 100 positives significantly increased corresponding to the descending of the CtV of hrHPV, HPV16-plus and pooled 12-HPV. Compared with high-CtV groups (CtV > 33.2 for hrHPV, CtV > 29.6 for pooled 12-HPV), the relevant risks (RRs) of CIN2+ for hrHPV and pooled 12-HPV positive groups with low-CtV (CtV ≤ 33.2 and ≤ 29.6, respectively) were 3.2 (95%CI 2.18–4.80) and 2.3 (95%CI 1.50–3.45). Similarly, the RRs of CIN3+ for hrHPV and pooled 12-HPV positive groups with low-CtV were 6.5 (95%CI 2.83–14.80) and 2.7 (95%CI 1.15–6.39), respectively. The RRs of CIN2+ for medium- (30.3 < CtV ≤ 37.4) and low- (≤ 30.3) CtV HPV16-plus positives were 5.1 (95%CI 0.68–38.38) and 20.6 (95%CI 2.96–143.92) related to high-CtV (> 37.4) groups, and the CIN3+ incidence in low-CtV value group was nine-fold higher of that in medium-CtV ones [RRs, 9.0 (95%CI 2.89–28.10)]. In comparing with the algorithms of “HPV16-plus/18-plus + cytology ≥ ASCUS for pooled 12-HPV”, triage algorithm “HPV16-plus/18-plus + Ct value ≤ 33.2 for pooled 12-HPV” could achieve a comparable sensitivity of 93.2%.

Conclusion

HPV viral loads reflected by Ct values for hrHPV, HPV16-plus and pooled 12-HPV from Cobas4800 HPV testing were directly associated with the severity of cervical lesions. A lower HPV genotype-specific Ct value prompted a significantly high CIN3+ risk of 4% or higher in women positive of hrHPV, HPV16-plus or pooled 12-HPV, indicating that HPV viral load reflected by Ct values on Cobas4800 may be a promising risk indicator in management of abnormalities from primary cervical cancer screening.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13027-022-00440-4.

Impact of modulation of telomerase and cancer stem-cell marker OCT4 axis in cervical cancer pathogenesis with underlying HPV16 infection

Lacunae exist in the molecular event(s) specificity associated with cervical cancer (CaCx) pathogenesis. The present study aimed to evaluate the significance of telomerase-cervical cancer stem cells (CSCs) modulation in CaCx pathogenesis with underlying HPV16 infection. The study included HPV16 positive cases only (N = 65) of the total enrolled cases from Northeast India. The analysis of viral load and the differential messenger RNA expression of E6, E7, hTERT, hTR, and cancer stem-cell markers was studied by real-time polymerase chain reaction. Further the protein and colocalization study for E6, hTERT, and oct4 was performed by immunofluorescence. The real-time polymerase chain reaction based analysis showed an upregulation of HPV16 viral oncoprotein E6 and E7, and telomerase component hTERT and hTR expression and their correlation in CaCx susceptibility and severity. The hTERT expression correlated with viral load; while the E6 and telomerase protein expression colocalized in the nucleus. The CSCs marker octamer-binding transcription factor 4 (OCT4) was significantly upregulated in CaCx cases, was associated with CaCx susceptibility and severity, and colocalized with E6 expression in the nucleus as revealed from the immunofluorescence studies. To conclude, the telomerase-OCT4 axis modulation holds key in HPV16 CaCx pathogenesis mediated by HPV16 E6 viral oncoprotein expression, and underlines its potential for therapeutic targeting.

Type-specific high-risk human papillomavirus viral load as a viable triage indicator for high-grade squamous intraepithelial lesion: a nested case- control study

Purpose

Currently, the associations between type-specific high-risk human papillomavirus (HR-HPV) viral loads and cervical lesions are still inconsistent. We aimed to assess the type-specific HR-HPV viral load as a risk triage indicator for development of high-grade squamous intraepithelial lesion or worse (≥HSIL).

Patients and methods

A total of 19,446 women who underwent primary screening for cervical cancer using Cervista^® HR-HPV and cytology assays were enrolled. The viral loads of 1,396 HR-HPV-positive specimens confirmed by Cervista^® assay were detected by BioPerfectus Multiplex Real-Time PCR assay. The correlation between viral loads and cervical lesions was analyzed. The optimal cutoffs of individual HR-HPV viral loads used to predict ≥HSIL were determined from the receiver operating characteristic curve. A logistic regression model was used to analyze the relationship between covariates and the probability of ≥HSIL.

Results

The viral loads of HPV-16, -31, -33, -52, and -58 were positively correlated with the severity of the cervical lesion, which was significantly elevated in patients with ≥HSIL, whereas those of HPV-18, -45, -56, -59, and other types were not. The optimal cutoffs of the log₁₀-transformed viral loads for HPV-16, -31, -33, -52, and -58 in identifying ≥HSIL were 4.26, 4.46, 4.48, 4.36, and 4.26 copies per 10,000 cells, respectively. Furthermore, multivariate analysis indicated that type-specific viral loads of HPV-16, -31, -33, -52, and -58 exceeding the cutoffs could be independent risk factors for the incidence of ≥HSIL.

Conclusion

The BioPerfectus Multiplex Real-Time PCR viral load assay provides viable triage for ≥HSIL when using appropriate cutoff levels.

Cervical cancer screening in women vaccinated against human papillomavirus infection: Recommendations from a consensus conference

In Italy, the cohorts of women who were offered Human papillomavirus (HPV) vaccination in 2007/08 will reach the age (25years) for cervical cancer (CC) screening from 2017. The simultaneous shift from cytology-based screening to HPV test-based screening gives the opportunity for unprecedented reorganisation of CC prevention. The ONS (National Screening Monitoring Centre) Directive and the GISCi (Italian Group for Cervical Screening) identified the consensus conference as the most suitable method for addressing this topic. A summary of consensus recommendations is reported here. The main objective was to define the best screening methods in girls vaccinated against HPV and the knowledge required for defining evidence-based screening strategies. A Jury made recommendations about questions and proposals formulated by a panel of experts representative of Italian scientific societies involved in CC prevention and based on systematic reviews of literature and evidence. The Jury considered changing the screening protocols for girls vaccinated in their twelfth year as appropriate. Tailored screening protocols based on vaccination status could be replaced by "one size fits all" protocols only when a herd immunity effect has been reached. Vaccinated women should start screening at age 30, instead of 25, with HPV test. Furthermore, there is a strong rationale for applying longer intervals for re-screening HPV negative women than the currently recommended 5years, but research is needed to determine the optimal screening time points. For non-vaccinated women and for women vaccinated in their fifteenth year or later, the current protocol should be kept.

Type-dependent association between risk of cervical intraepithelial neoplasia and viral load of oncogenic human papillomavirus types other than types 16 and 18

Studies of the clinical relevance of human papillomavirus (HPV) DNA load have focused mainly on HPV16 and HPV18. Data on other oncogenic types are rare. Study subjects were women enrolled in the atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL) triage study who had ≥1 of 11 non-HPV16/18 oncogenic types detected during a 2-year follow-up at 6-month intervals. Viral load measurements were performed on the first type-specific HPV-positive specimens. The association of cervical intraepithelial neoplasia grades 2-3 (CIN2/3) with type-specific HPV DNA load was assessed with discrete-time Cox regression. Overall, the increase in the cumulative risk of CIN2/3 per 1 unit increase in log₁₀ -transformed viral load was statistically significant for four types within species 9 including HPV31 (adjusted hazard ratio [HR _adjusted ] = 1.32: 95% confidence interval [CI], 1.14-1.52), HPV35 (HR _adjusted  = 1.47; 95% CI, 1.23-1.76), HPV52 (HR _adjusted  = 1.14; 95% CI, 1.01-1.30) and HPV58 (HR _adjusted  = 1.49; 95% CI, 1.23-1.82). The association was marginally significant for HPV33 (species 9) and HPV45 (species 7) and was not appreciable for other types. The per 1 log₁₀ -unit increase in viral load of a group of species 9 non-HPV16 oncogenic types was statistically significantly associated with risk of CIN2/3 for women with a cytologic diagnosis of within normal limits, ASC-US, or LSIL at the first HPV-positive visit but not for those with high-grade SIL. Findings suggest that the viral load-associated risk of CIN2/3 is type-dependent, and mainly restricted to the species of HPV types related to HPV16, which shares this association.

The DNA load of six high-risk human papillomavirus types and its association with cervical lesions

Background

Analysing human papillomavirus (HPV) viral load is important in determining the risk of developing cervical cancer (CC); most knowledge to date regarding HPV viral load and cervical lesions has been related to HPV-16. This study evaluated the association between the viral load of the six most prevalent high-risk viral types in Colombia and cervical intraepithelial neoplasia (CIN) frequency.

Methods

114 women without CIN and 59 women having CIN confirmed by colposcopy, all of them positive by conventional PCR for HPV infection in the initial screening, were included in the study. Samples were tested for six high-risk HPV types to determine viral copy number by real-time PCR. Crude and adjusted odds ratios (OR_a) were estimated for evaluating the association between each viral type’s DNA load and the risk of cervical lesions occurring.

Results

The highest viral loads were identified for HPV-33 in CIN patients and for HPV-31 in patients without lesions (9.33 HPV copies, 2.95 interquartile range (IQR); 9.41 HPV copies, 2.58 IQR). Lesions were more frequent in HPV-16 patients having a low viral load (3.53 OR_a, 1.16–10.74 95%CI) compared to those having high HPV-16 load (2.62 OR_a, 1.08–6.35 95%CI). High viral load in HPV-31 patients was associated with lower CIN frequency (0.34 OR_a, 0.15–0.78 95%CI).

Conclusions

An association between HPV DNA load and CIN frequency was seen to be type-specific and may have depended on the duration of infection. This analysis has provided information for understanding the effect of HPV DNA load on cervical lesion development.

The shotgun proteomic study of the human ThinPrep cervical smear using iTRAQ mass-tagging and 2D LC-FT-Orbitrap-MS: the detection of the human papillomavirus at the protein level

The ThinPrep cervical smear is widely used in clinical practice for the cytological and molecular screening against abnormal cells and Human Papillomavirus (HPV) infection. Current advancements made to LC-MS proteomics include the use of stable isotope labeling for the in-depth analysis of proteins in complex clinical specimens. Such approaches have yet to be realized for ThinPrep clinical specimens. In this study, an LC-MS method based on isobaric (iTRAQ) labeling and high-resolution FT-Orbitrap mass spectrometry was used for the proteomic analysis of 23 human ThinPrep smear specimens. Tandem mass spectrometry analysis was performed with both nitrogen high collision dissociation (HCD MS/MS) and helium collision induced dissociation (CID MS/MS) peptide fragmentation modes. The analysis of three 8-plex sample sets yielded the identification of over 3200 unique proteins at FDR < 1%, of which over 2300 proteins were quantitatively profiled in at least one of the three experiments. The interindividual variability served to define the required sample size needed to identify significant protein expression differences. The degree of in-depth proteome coverage allowed the detection of 6 HPV-derived proteins including the high-risk HPV16 type in the specimens tested. The presence of the HPV strains of origin was also confirmed with PCR-hybridization molecular methods. This proof-of-principle study constitutes the first ever report on the nontargeted analysis of HPV proteins in human ThinPrep clinical specimens with high-resolution mass spectrometry. A further testament to the sensitivity and selectivity of the proposed study method was the confident detection of a significant number of phosphopeptides in these specimens.

Comparison of oncogenic HPV type-specific viral DNA load and E6/E7 mRNA detection in cervical samples: results from a multicenter study

High-risk human papillomavirus (HR-HPV) genotype viral load and E6/E7 mRNA detection are proposed as surrogate markers of malignant cervical lesion progression. Currently, the use of commercially available DNA-based or mRNA-based tests is under investigation. In this study, the viral DNA load and E6/E7 mRNA detection of the five most common HR-HPV types detected in cervical cancer worldwide were compared in 308 cervical samples by using in-house type-specific quantitative real-time PCR assays and PreTect HPV-Proofer test, respectively. Sensitivity and negative predictive values were higher for the HPV-DNA assays combined (95.0% and 96.0%, respectively) than the RNA assays (77.0% and 88.0%, respectively); conversely, the mRNA test showed a higher specificity and higher positive predictive value (81.7% and 66.9%, respectively) than the DNA test (58.6% and 52.5%, respectively) for detecting histology-confirmed high-grade cervical intraepithelial neoplasia. A significantly higher association between viral DNA load and severity of disease was observed for HPV 16 and 31 (γ = 0.62 and γ = 0.40, respectively) than for the other HPV types screened. A good degree of association between the two assays was found for detection of HPV 16 (k = 0.83), HPV 18 (k = 0.72), HPV 33 (k = 0.66), and HPV 45 (k = 0.60) but not for HPV 31 (k = 0.24). Sequence analysis in L1 and E6-LCR regions of HPV 31 genotypes showed a high level of intra-type variation. HR-HPV viral DNA load was significantly higher in E6/E7 mRNA positive than negative samples (P < 0.001), except for HPV 31. These findings suggest that transcriptional and replicative activities can coexist within the same sample.

Detection of human Papillomavirus 18 in cervical cancer samples using PCR-ELISA (DIAPOPS)

BACKGROUND AND OBJECTIVES

Human Papillomavirus (HPV) infection is a major risk factor for adenocarcinoma of the cervix. The high-risk types of the virus such as HPV16 and HPV18, which possess the E6 and E7 oncogenes, are responsible for approximately 50% of all cervical cancers. A rapid, sensitive and specific test has been proposed for detection of HPV to improve cervical cancer screening programs.

OBJECTIVES

The aim of this study was to develop a fast PCR-ELISA assay designated as DIAPOPS (Detection of Immobilized Amplified Products in a One Phase System)for detection of HPV16 and HPV18 types in SCC samples and Pap smears. The type specific primers and probes were designed for PCR and PCR-ELISA. The amplified products were hybridized with a specific biotin-labeled probe for HPV18 inner amplicons. The hybrids were detected with peroxidase conjugated avidin. The test was performed on the paraffin block and Pap smear samples from the cervical cancer patients, and the results of DIAPOPS were compared with conventional PCR assay.

RESULTS

The 70 samples (SCC and Pap smear samples) were collected from Imam Khomeini and Mirzakoochak Khan Hospitals in Tehran. The PCR-based method detected six HPV16 positive, three HPV18 positive and Two HPV33 positive samples. DIAPOPS results were compared with the conventional PCR results and they showed an increase in sensitivity of the DIAPOPS test. Not only all of them were confirmed by PCR-ELISA but also three samples that conventional PCR showed negative for HPV18, were demonstrated positive by the PCR-ELISA method.

CONCLUSION

The results of the study show that modified PCR-ELISA assay is more sensitive to detect HPV types and can be used for diagnostic purposes.

Is human papillomavirus screening preferable to current policies in vaccinated and unvaccinated women? A cost-effectiveness analysis

Objectives

Italy was the first European nation to offer free vaccination against human papillomavirus (HPV) types 16 and 18. The vaccination is actively encouraged and is available free of charge to 11-year-old girls. The introduction of new technologies such as HPV DNA testing and HPV vaccination requires cost-effectiveness analysis of cervical cancer strategies in Italy for both vaccinated and unvaccinated women.

Methods

A calibrated Markov model was developed to describe the natural history of HPV infection and cervical carcinogenesis. We performed a microsimulation generating the life histories of 10 million women. Changes in these life histories occur as consequences of prevention strategies. We estimated costs of screening activities using an activity-based costing analysis. We assessed lifetime risk due to cervical cancer, lifetime costs and quality-adjusted life-expectancy (QALE) for 18 scenarios. Strategies varied by screening interval (three and five years), primary and triage test (Pap test and HPV DNA test), and HPV 16 and 18 vaccination.

Results

The current screening policy (Pap test every three years) is more costly and less effective than HPV DNA test and Pap test triage every five years. For unvaccinated women an HPV DNA test every five years with a Pap test triage was cost-effective (ICER €5753/QALE). Vaccination followed by the same screening strategy was cost-effective (ICER €23,951/QALE) for women who are eligible to be vaccinated.

Conclusions

Our findings strongly support changing the Pap screening policy to the use of HPV DNA as a primary test with Pap test triage for both vaccinated and unvaccinated women.

Prevalence of human papillomavirus infection in women attending a gynecology/oncology clinic in Qatar

Aim: Human papillomavirus (HPV) detection is very important for the evaluation of prevention strategies in cervical cancer and other HPV-related diseases. This study aimed to assess the prevalence of high-risk HPV infection in a cohort of Qatari residents, and correlate this with cytology and potential risk factors. Method: The study utilized cervical cytology and HPV DNA testing methods, high-risk screen real-time PCR, to detect high-risk HPV genotype infections in a sample of Qatar’s female population. A series of 95 women attending the Gynecology/Oncology Clinic at Hamad Medical Corporation between August 2007 and May 2008 were enrolled in the study. Cervical smears isolated from patients were subjected to real-time PCR to confirm the presence of HPV DNA. The smears were characterized as atypical squamous cells of undetermined significance (ASCUS); low-grade squamous intraepithelial lesions (LGSIL) and high-grade squamous intraepithelial lesions (HGSIL). As a secondary outcome, risk factors for HPV infection were also assessed. However, the samples were not case-controlled for these. Results: A total of 28 women had normal smears and 65 had abnormal smears. Among the 65 women in the study population with abnormal smears, 33 had ASCUS (18 of them were HPV DNA positive), 21 had LGSIL (18 were HPV DNA positive), eight had HGSIL (four were HPV DNA positive) and the remaining three had squamous cell carcinoma (two were HPV DNA positive). Conclusion: The overall prevalence of high-risk HPV in our study population (n = 95) was 64%. The relatively high prevalence of HPV 52, 56 and 16 among the study group has important implications in vaccine prophylaxis in Qatar.

Frequency and types of human papillomavirus among pregnant and non-pregnant women with human immunodeficiency virus infection in Recife determined by genotyping

Women with human immunodeficiency virus (HIV) infection present a higher risk of infection by the human papillomavirus (HPV) and cervical cancer. To determine HPV genotypes and frequencies among HIV-positive women, an analytical cross-sectional study was carried out on 147 women (51 were pregnant and HIV-positive, 45 pregnant and HIV-negative and 51 HIV-positive and not pregnant), who were attended at a maternity hospital in Recife between April 2006-May 2007. They answered a questionnaire and underwent a gynaecological examination, with samples collected for HPV investigation by PCR, hybrid capture II, oncotic colpocytology (Papanicolau) and colposcopy. The frequency of HPV DNA was 85.3% (122/143), with a high proportion of HPV types that have been identified as high risk for cervical cancer. Among HIV-positive pregnant women, there was an HPV prevalence of 96% (48/50), of whom 60.4% (29/48) were high-risk. HPV 16, 58, 18, 66 and 31 were the most frequent types. Colpocytological abnormalities were observed in 35.3% (18/51) of HIV-positive non-pregnant women, 21.6% (11/51) of HIV-positive pregnant women and 13.3% (6/45) of HIV-negative pregnant women with a predominance of low-level lesions. A high prevalence of HPV infection was identified, especially with the high-risk types 16, 58, 18 and 66. This study identified high-risk HPV types in all three groups examined (HIV-positive pregnant women, HIV-negative pregnant women and HIV-positive not pregnant), characterising its distribution in this setting.

Epidemiology and genotype distribution of human papillomavirus (HPV) in women of Sardinia (Italy)

The human papillomavirus (HPV) infection is necessary for the development of cervical cancer. Our study aims to evaluate the rate of HPV circulation in our population, to identify the prevalent genotypes and to establish correlation with cervical abnormalities. Furthermore, the awareness of women about HPV issues was investigated. This study included 864 women attending the Oncologic Prevention Service for their routine Pap test screening or the Health Promotion Mother-Child Service for counselling about sexual activity, from July 2006 to September 2007. All the participants gave their informed consent to be enrolled in the study and were invited to fill in a questionnaire about the socio-cultural state, sexual activity and awareness about HPV. The women samples were tested for HPV-DNA and HPV genotypes: any type of HPV-DNA was detected in 31.0% of the women; single or multiple infections sustained by HPV-16 or HPV-18 represented 43.5% of all HPV infections, accounting for infections in 11.8% of the recruited women. The HPV and high-risk HPV (HR-HPV) prevalence significantly declined in women older than 46 years. The Pap test result was available in 490 women; 48.1% of the Pap test positive women had also an HPV infection and among these 22.7% were infected by HPV-16 and/or HPV-18 genotype, while 51.9% (94/181) were HPV negative. The analysis by binary logistic regression showed that genotype 16 and/or 18 is a risk factor for the Pap positive test with a odds ratio (OR) of 2.9 (95% C.I. 1.4-5.9) and 3.6 (95% C.I. 1.58-8.42) respectively, while age is a protective factor (OR 0.97, C.I. 95% 0.96-0.99); furthermore, the mean age at the first sexual intercourse and the mean number of partners since the beginning of sexual activity, were statistically associated with the risk of HPV infection. More than half of women were aware about HPV, its sexual transmission and of its correlation with cervix cancer. Our findings evidenced that HPV infection is frequent in women aged 18-46 years in Sardinia and particularly that 16 and 18 HPV genotypes are detectable in more than 40% of the infected women. The proportion of women informed about HPV issues is sufficient to guarantee an aware approach to HPV vaccination.

Quantitative human papillomavirus 16 and 18 levels in incident infections and cervical lesion development

Human papillomavirus (HPV) RNA levels may be a more sensitive early indicator of predisposition to carcinogenesis than DNA levels. We evaluated whether levels of HPV-16 and HPV-18 DNA and messenger RNA (mRNA) in newly detected infections are associated with cervical lesion development. Female university students were recruited from 1990 to 2004. Cervical samples for HPV DNA, HPV mRNA, and Papanicolaou testing were collected tri-annually, and women were referred for colposcopically directed biopsy when indicated. Quantitative real-time polymerase chain reaction of L1 and E7 DNA and E7 mRNA was performed on samples from women with HPV-16 and HPV-18 infections that were incidently detected by consensus PCR. Adjusting for other HPV types, increasing E7 cervical HPV-16 mRNA levels at the time of incident HPV-16 DNA detection were associated with an increased risk of cervical intraepithelial neoplasia grade 2-3 (HR per 1 log(10) increase in mRNA = 6.36, 95% CI = 2.00-20.23). Increasing HPV-16 mRNA levels were also associated with an increased risk of cervical squamous intraepithelial lesions; the risk was highest at the incident positive visit and decreased over time. Neither HPV-16 E7 DNA levels nor HPV-18 E7 DNA nor mRNA levels were significantly associated with cervical lesion development. Report of >1 new partner in the past 8 months (relative to no new partners) was associated with increased HPV mRNA (viral level ratio [VLR] = 10.05, 95% CI = 1.09-92.56) and increased HPV DNA (VLR = 16.80, 95% CI = 1.46-193.01). In newly detected HPV-16 infections, increasing levels of E7 mRNA appear to be associated with an increased risk of developing cervical pre-cancer.

Prevalence and viral load of oncogenic human papillomavirus types associated with cervical carcinoma in a population of North Italy

A cross-sectional study was carried out in a population of North Italy to determine the prevalence of eight oncogenic human papillomavirus (HPV) types most commonly found in cervical carcinoma and to study the relationship between HPV DNA loads and severity of disease. A total of 597 cervical samples obtained from patients with pathological findings (n = 472) and from women with normal cytology (n = 125) were analyzed by means of normalized Real-time PCR assays to quantify HPV-16, -18, -31, -45, and -33 group (including -33, -52, -58, -67); the normalization of oncogenic HPV viral load was carried out by quantitation of a single copy gene. The two most common oncogenic HPV types found were 16 and 31 (24.3% and 22.9% of pathological samples, respectively); multiple infections were demonstrated in 22% of pathological samples. Overall, the HPV total viral load was found to increase with increasing severity of associated lesions, although a stronger association was observed only for HPV-31 and HPV-16 (gamma = 0.49 and 0.41, respectively) as compared to HPV-18 and -33 group (gamma = 0.19 and 0.02, respectively). However, we found that high levels of HPV-31 or 33 group DNA could be prognostic of minor oncogenic risk for high-grade squamous intraepithelial lesions (H-SIL) (age adjusted odds ratio [AORs] = 1.57 and 1.26, respectively) than HPV-16 and HPV-18 (AORs = 30 and 8, respectively). The AORs also increased with HPV total viral load and reached a maximum of AORs = 15.7. Thus, HPV load is a type-dependent risk marker for the development of H-SIL.

Disruption of HPV 16 E1 and E2 genes in precancerous cervical lesions

The presence of HPV 16 E1 and E2 genes was detected in cervical cytological samples using polymerase chain reaction assays. A total of 48 samples were analyzed from patients with HPV 16 infections associated with 13 low-grade cervical intraepithelial neoplasia and 35 high-grade cervical intraepithelial neoplasia. Disruption/deletion sites, within E1 and E2 genes, were detected using 6 primer pairs spanning the entire gene sequences. This technique is not able to recognize mixed DNA forms (integrated plus episomal DNA); therefore, it detects only the presence of pure integrated DNA. Both E1 and E2 genes were detected in 84.6% and in 62.9% of low and high-grade lesions, respectively. The rate of samples with disrupted/deleted genes was significantly higher in high-grade cervical intraepithelial neoplasia than in low-grade cervical intraepithelial neoplasia (P<0.05). In high-grade cervical intraepithelial neoplasia the disruption/deletion pattern involved both E1 and E2 genes and E2 gene was always involved, while in the low grade cervical intraepithelial neoplasia only E1 gene was involved. In conclusion, in high-grade cervical lesions E2 gene seems a suitable target to identify HPV 16 DNA integration into cellular genome.

Analysis of human papillomavirus type 16 (HPV16) DNA load and physical state for identification of HPV16-infected women with high-grade lesions or cervical carcinoma

Integration of human papillomavirus (HPV) DNA into the host cell genome is a frequent event in cervical carcinogenesis, even though this phenomenon does not seem to be mandatory for cervical cancer development. Our objective was to describe the load and physical state of HPV type 16 (HPV16) DNA in a series of cervical samples representative of the natural history of cervical cancer. We used a combination of three real-time PCR assays targeting E6, E2, and albumin genes to calculate HPV16 load (E6 and albumin) and the E2/E6 ratio as a surrogate of integration. This method was applied to 173 HPV16-positive cervical samples. Results show that viral load increases with the lesion grade (from 102 HPV16 DNA copies per 10(3) cells in normal samples up to 56,354 copies per 10(3) cells in cancers), while E2/E6 ratio decreases (from 1 in normal samples down to 0.36 in cancers). We propose that, according to this technique, an HPV16 viral load of higher than 22,000 copies/10(3) cells or an E2/E6 ratio of lower than 0.50 allows the identification of women with prevalent high-grade lesions or worse with a high specificity. In conclusion, both viral load and E2/E6 ratio, used in combination with an appropriate cutoff value, are suitable to screen women with prevalent cervical intraepithelial neoplasia grade 2 or 3 or cancer. Therefore, these assays would be useful in addition to routine HPV testing to more accurately identify women with (pre)cancerous lesions.

Cervical cancer screening: from molecular basis to diagnostic practice, going through new technologies

In the era of Human Papillomavirus (HPV) vaccination, a lot of misunderstanding still exists among healthcare professionals and patients regarding HPV infection. The purpose of this review is to synthesize the clinical molecular mechanisms that contribute to HPV-mediated cervical carcinogenesis, as well as to appraise the current status of new biomarkers and technologies in terms of available data on clinical applications and future promises.

Frequency and clinical significance of human beta-herpesviruses in cervical samples from Italian women

Human papillomaviruses (HPVs) are necessary, but not sufficient, for the development of cervical cancer (CC). Human beta-herpesviruses (beta-HHVs) have been suggested as possible cofactors in the oncogenesis of CC. In this cross-sectional study, the prevalence and possible association of cytomegalovirus (CMV), HHV-6 and -7 with HPV presence was investigated by quantitative real-time PCR assays in cervical samples obtained from 208 italian women. The two most common high-risk HPV types found were 31 and 16. Overall, the positive rates for CMV, HHV-6 and HHV-7 were 66%, 25%, and 6%, respectively. In particular, the prevalence of CMV was found to be extremely high irrespective of either the cytological category or HPV positivity. The prevalence of HHV-6 DNA was significantly higher in high-grade squamous intraepithelial lesions (HSIL) respect to normal women (P < 0.017); by contrast, the prevalence HHV-7 DNA was generally low and not associated with SIL. Copresence of CMV and HHV-6 DNA was found to be significantly higher in patients with SIL respect to normal women (P < 0.05). No correlation was demonstrated between the viral load of all three beta-HHVs and the different cytological stages or with the HPV presence. A few patients with severe disease however showed very high viral loads which for HHV-6 may be indicative of viral integration. In conclusion, this study suggests that CMV and HHV-7 alone are probably not implicated in the oncogenesis of CC whilst HHV-6 alone or together with CMV may contribute to the development of CC.

Utilization of human papillomavirus testing for cervical cancer prevention in a university hospital

This study aimed to evaluate the performance and cost of using polymerase chain reaction (PCR) and hybrid capture in the detection of cervical intraepithelial neoplasia (CIN) in patients with cytological abnormalities (ASCUS/low-grade squamous intraepithelial lesion--LSIL), and the feasibility of implementing these methods in Brazil's Unified National Health System (SUS). Colposcopy gave a negative predictive value of 92.86% and efficiency of 87.8% for diagnosing CIN. The sensitivity of PCR and hybrid capture for detecting CIN was 83.33% and 66.67%, respectively, and the negative predictive value for diagnosing CIN2/CIN3 was 100% and 94.74%, respectively. The annual cost for 80 patients was lower when all patients with ASCUS/LSIL were referred for colposcopy than when HPV testing was performed and those with positive results were referred for colposcopy. Therefore, at present, it is financially unfeasible for the National Health System to implement HPV testing to screen patients with cytological abnormalities (ASCUS/LSIL). However, considering that large-scale use might make such methods cheaper, PCR should be the chosen method, since it is less expensive, more sensitive, and has a high negative predictive value.

Qualitative PCR-ELISA protocol for the detection and typing of viral genomes

PCR is an established technique providing rapid and highly productive amplification of specific DNA sequences. The demand for equally rapid, sensitive and objective methods to achieve detection of PCR products has led to the coupling of PCR with ELISA. PCR-ELISA involves direct incorporation of labeled nucleotides in amplicons during PCR-amplification, their hybridization to specific probes and hybrid capture-immunoassay in microtiter wells. PCR-ELISA is performed in 1 d and is very flexible, with the ability to process simultaneously up to 96 or 384 samples. This technique is potentially automatable and does not require expensive equipment, and thus can be fundamental in laboratories without access to a real-time PCR thermocycler. PCR-ELISA has mainly been used to detect infectious agents, including viruses, bacteria, protozoa and fungi. A PCR-ELISA protocol for the qualitative detection of papillomavirus genomes and simultaneous typing of different genotypes are detailed here as an example of the technique.

Etiology and pathogenesis of precancerous lesions and invasive cervical carcinoma

Cervical cancer is the second most common gynecological malignancy in the world. Human papilloma virus (HPV) infection is the leading ethiologic agent in the development of premalignant and malignant cervical diseases. HPV is a member of the Papovaviridae family and until now over 100 types have been recognized. There are two types of viral infection: latent and productive. Virus induced oncogenesis is the result of interaction between virus oncoproteins E6 and E7 and tumor supresor host genes p53 and Rb. Many cofactors such as immunosuppression, early sexual relationship, multiple sexual partners, other sexualy transsmited infections and smooking are contributing factors of the precancerous and invasive cervical lesions. According to the oncogenic potential HPV are divided into three groups: low, intermediate and high oncogenic risk viruses. Molecular technics which are used for the virus detection are: In situ hibridisation,, Hybrid capture test and polymerasa chain reaction. Human papilloma virus testing has an important role in the follow up and treatment of women with 'atypical squamous cells of unknown significant' changes in cervical smears and low-grade squamous intraepithelial lesions, changes in punch biopsy.

Viral DNA load, physical status and E2/E6 ratio as markers to grade HPV16 positive women for high-grade cervical lesions

OBJECTIVES

Cervical intraepithelial neoplasias (CIN) associated with high-risk (HR) human papillomavirus infection, in addition to HR-HPV typing need other viral marker testing to distinguish a subset of lesions with clinical relevant infections. This study has evaluated the significance of viral markers, such as viral load, physical status and E2/E6 ratio, to stratify HPV16 infected women at a single point in time for grade of cervical lesions.

METHODS

One hundred sixty-six cytological specimens were selected from women with low (n=72) and high (n=94) grade squamous intraepithelial lesions (SIL), and positive to HPV16. All the 72 LSIL were CINI, 83 of the 94 HSIL were CINII/III and 11 SCC (Squamous Cervical Carcinoma). Cytological specimens were analysed by two different SYBR Green Real-time PCR assays (RT-PCR). Specific primers for both E2 and E6 viral genes and GAPDH cellular gene were designed to determine viral load, physical status and E2/E6 ratio.

RESULTS

The viral load was significantly higher in HSIL than in LSIL. In CINI episomal DNA was prevalent (72.2%), mixed forms (episomal and integrated) were 27.8%, suggestive of an early integration of viral DNA into cellular genome, no pure integrated forms were detected. However in CINII/III mixed DNA forms were prevalent (73.5%). In SCC pure integrated DNA was prevalent (81.8%) in absence of episomal forms. E2/E6 ratio decreased significantly from CINI to CINII/III and SCC with a linear trend. The logistic regression analysis showed that viral load higher than 1.38x10(6) genome copies per 300 ng of total DNA associated with E2/E6 ratio lower than 0.90 was highly significant in differentiating CINII/III versus CINI, while the only E2/E6 value lower than 0.17 was significant in differentiating SCC from CINI.

CONCLUSIONS

Viral load higher than 1.38x10(6) genome copies per 300 ng of total DNA and E2/E6 ratio values allow HPV16 infected women with high grade cervical intraepithelial lesions to be recognized.

Variation in human papillomavirus type-16 viral load within different histological grades of cervical neoplasia

The objective of this study was to investigate variation in human papillomavirus (HPV) type-16 load within histologically defined grades of cervical intraepithelial neoplasia. Two hundred and thirty-seven liquid based cytology samples were collected from women attending colposcopy clinics, DNA was extracted, and presence of virus determined by PCR-enzyme immunoassay. Quantitative real-time PCR was used to determine viral load for 70 HPV-16 positive single infections. Viral load was expressed as the ratio of copies of the viral L1 gene to copies of the human beta-globin gene. Measurements varied from 0.019 to 4,194 HPV genomes per cell. Our data demonstrate that in cervical neoplasia, HPV load tends to correlate with disease severity, but that the number of viral genomes/cell varies considerably within histological grades. This variation within disease grades currently limits the clinical utility of viral load measurement.

[Oncogenic viruses and their role in tumour formation]

Oncogenic viruses trigger persistent infections, which can stimulate uncontrolled cell growth by inducing cell transformation. Different oncogenic viruses use different mechanisms for infecting cells. Most oncogenic DNA viruses integrate transforming sets of genes into the host chromosome and encode proteins that bind and inactivate cell growth regulatory proteins, such as p53 and retinoblastoma gene product. Tumourous RNA viruses use different oncogenic mechanisms. Some of them encode oncogenic proteins that are almost identical to the cellular proteins involved in the control of cellular growth. The overproduction or altered function of these oncogenic materials stimulates cell growth. These RNA viruses can cause tumours rapidly. The second group of oncoviruses integrates their promoter sequences and viral enhancers near to the cellular growth-stimulating gene, initiating the transformation of the cell. The third group of RNA tumour viruses encodes a protein tax that transactivates the expression of cellular genes. Virus-induced malignant transformation of the cell represents the first step in the complex process of oncogenesis.

Oligonucleotide microarray with RD-PCR labeling technique for detection and typing of human papillomavirus

Currently, screening for high-risk human papillomavirus (HPV) infection remains an important health concern throughout the world, because of the close association between certain types of HPV and cervical cancer. In this study, we explore the possibility of using approximately 70mer oligonucleotide microarray for detection and genotyping of HPV. The approximately 70mer type-specific oligonucleotide probes of four different types HPV were designed by using biological software Array designer 2.0, which analyzed the whole genome sequences of HPV and selected optimal probes. These probes were synthesized and printed onto the surface of glass slides in order to prepare a low-density microarray. HPV samples were labeled with fluorescence dyes Cy3 using a method of restriction display polymerase chain reaction (RD-PCR). HPV plasmid DNA was restricted with Sau3A I to produce multiple fragments that were ligated to adaptors subsequently and used as PCR template. PCR labeling was performed with the fluorescently labeled universal primer (Cy3-UP) whose sequence is designed according to the adaptor of the RD-PCR approaches. The labeled samples were hybridized with the oligonucleotide microarray. The scanning results showed that HPV DNA hybridized specifically with multiple spots correspondingly to show positive signals, whereas no signals were detected of all the negative and blank controls. These results demonstrated that approximately 70mer oligonucleotide microarray can be applied to HPV detection and genotyping. The application of RD-PCR in the sample labeling can increase significantly the sensitivity of the assay and will be especially useful for the discriminate diagnosis of multiple pathogens.

Association between quantitative high-risk human papillomavirus DNA load and cervical intraepithelial neoplasm risk

Human papillomavirus (HPV) infection is a high-risk factor for cervical intraepithelial neoplasm (CIN) but the association between the quantitative HPV DNA load and the severity of CIN remains controversial. We conducted a community study to investigate the correlation between the two. Potential study subjects were selected through Pap smear screening in Kaohsiung County, Taiwan. Ninety-one subjects with either their first case of inflammation or > or =CIN1 by biopsy confirmation were assigned to a case group; 175 normal subjects with negative findings by Pap smears or biopsies were assigned to a control group. Cervical HPV load was detected with Hybrid Capture II assay for high-risk HPV infection, with nested PCR for high- and low-risk HPV infection, and with type-specific PCR for HPV type 16 (HPV-16). Individuals with positive high-risk HPV infection had an increased risk of developing CIN. Compared with HPV-negative subjects, the odds ratios were 32.2 [95% confidence interval (95% CI), 10.4-99.5] for subjects with CIN1, 37.2 (95% CI, 7.4-187.6) for subjects with CIN2, and 68.3 (95% CI, 14.1-328.5) for subjects with > or =CIN3 after adjusting for other confounding factors. The similar trend was also found among the HPV-16-negative individuals. In addition, high-risk HPV DNA load levels were highly correlated with the different grades of CINs in the overall population (Spearman's correlation coefficient r = 0.67, P < 0.0001, n = 266) and the HPV-16-negative population (Spearman's correlation coefficient r = 0.58, P < 0.0001, n = 234). We concluded that high-risk HPV infection, irrespective of HPV-16 infection, was highly and positively associated with the development of CIN.

Prevalence of alpha-papillomavirus genotypes in cervical squamous intraepithelial lesions and invasive cervical carcinoma in the Italian population

The aim of the present investigation was to define the spectrum of mucosotropic human papillomaviruses among 414 Italian women with normal cervices (n = 183), low- and high-grade cervical squamous intraepithelial lesions (n = 101 and 65, respectively), and invasive squamous cervical carcinomas (n = 65). Human papillomaviruses were detected by broad spectrum consensus-primer-pairs MY09/MY11 and GP5+/GP6+-based polymerase chain reaction using three amplification methods and were characterized by nucleotide sequence analysis. The prevalence rates of HPV infections was 19.7%, 63.4%, 80%, and 81.5% in patients with normal cervices, low-grade, and high-grade squamous intraepithelial lesions, and cervical carcinomas, respectively. Among the 205 HPV-positive patients, a total of 31 mucosal HPV genotypes were identified of which 16 types, epidemiological classified as high-risk viruses (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 66, 68, 73, and 82), have been found in 16.9%, 50.1%, 69.2%, and 78.5% of normal cervix, low-, and high-grade cervical squamous intraepithelial lesions, and cervical carcinoma groups, respectively. As expected, the HPV16 was the most represented viral type in all groups examined with frequency rates ranging from 8.7% in normal subjects to 58.5% in invasive carcinoma patients. Ten epidemiologically defined low-risk HPV types (HPV6, 11, 42, 54, 61, 70, 71, 72, 81, 83) were detected in 2.7%, 7.9%, and 6.1% of normal cervix, low-, and high-grade cervical squamous intraepithelial lesions, respectively, and in none of invasive carcinomas. Furthermore, five unknown risk viruses were detected in 3% of low-grade cervical squamous intraepithelial lesions (HPV30, 32, 67), in 3.1% of high-grade cervical squamous intraepithelial lesions (HPV62, 90), and in 1.5% of cervical carcinomas (HPV62). Larger epidemiological screening studies, with PCR amplification and followed by either hybridization-based procedures against sequence targets of all known HPV types or sequence analysis studies, are needed in order to assess the epidemiological risk of less represented HPV types, to identify unknown viruses, and to monitor the future eventual spread of unusual viral types related to vaccination programs and/or population mobility.

HPV DNA patterns and disease implications in the follow-up of patients treated for HPV16 high-grade carcinoma in situ

Twenty-five patients with high-grade cervical lesions associated with HPV16 infection were studied at the time of surgical treatment and followed up after conization. Before surgical treatment, the following parameters were analyzed: (1) physical status of HPV16 DNA, (2) viral load, (3) cytological presentation confirmed by histological diagnosis, and (4) colposcopy. At the time of conization, (5) margin presentation, and (6) cone biopsy were evaluated. At each stage of the follow-up (7) physical status of HPV16 DNA, (8) viral load, (9) cytological test, and (10) colposcopy were repeated. The correlation between the different parameters was examined. Significant differences in the viral loads were observed between integrated and episomal forms and between the coexisting integrated/episomal forms and the only episomal form, while no statistically significant differences were observed between integrated and coexisting forms. At the first stage of follow-up, 11 of 25 patients analyzed (44%) were negative to HPV DNA cytology and colposcopy tests, 13 of the 25 (52%) were HPV16 DNA negative, 17 (68%) cytology negative, and 20 (80%) colposcopy negative. At the closing stage, 15 of 25 subjects (60%) were negative to all three tests, 16 of the 25 (64%) were HPV16 DNA negative, 19 (76%) cytology negative, and 20 colposcopy negative (80%). These observations suggest that in surgery treated patients the viral clearance at the closing stage of follow-up was unrelated to the HPV DNA physical status and to the viral load before treatment, but was associated significantly with the effectiveness of surgery treatment, in particular with margin cone presentation.

Human papillomavirus genotype distribution in low-grade cervical lesions: comparison by geographic region and with cervical cancer

Low-grade squamous intraepithelial lesions (LSIL) associated with certain human papillomavirus (HPV) genotypes may preferentially progress to cervical cancer. HPV genotyping may thus have the potential to improve the effectiveness of screening programs and to reduce overtreatment. LSIL cases (n = 8,308) from 55 published studies were included in a meta-analysis. HPV genotype distribution was assessed by geographic region and in comparison with published data on cervical squamous cell carcinoma (SCC). HPV detection in LSIL was 80% in North America but less than 70% in other regions, most likely reflecting regional differences in LSIL diagnosis. Among 5,910 HPV-positive LSILs, HPV16 was the most common genotype (26.3%) followed by HPV31 (11.5%), HPV51 (10.6%), and HPV53 (10.2%). HPV-positive LSILs from Africa were 2-fold less likely to be infected with HPV16 than those in Europe, and HPV-positive LSILs from North America were more likely to be infected with HPV18 than those from Europe or South/Central America. Interpretation for rarer genotypes was hampered by variation in HPV testing methodology. SCC/LSIL prevalence ratios indicated that HPV16 was 2-fold and HPV18 was 1.5-fold more common in SCC than in HPV-positive LSIL, thus appearing more likely to progress than other high-risk genotypes (SCC/LSIL prevalence ratios between 0.05 and 0.85). HPV53 and HPV66 showed SCC/LSIL ratios of 0.02 and 0.01, respectively. HPV genotype distribution in LSIL differs from that in cervical cancer, highlighting the importance of HPV genotype in the risk of progression from LSIL to malignancy. Some regional differences in the relative importance of HPV genotypes in LSIL were noted.

Immunocytochemical staining of p16INK4a protein from conventional Pap test and its association with human papillomavirus infection

The p16INK4a protein is immunocytochemically detected in liquid-based (LB) specimens as a diagnostic marker of cervical dysplasia and neoplasia. Its up-regulation is promoted by high-risk human papillomavirus (HR-HPV) infection. We aimed to detect p16INK4a on conventional Papanicolaou (Pap) test (CPT) slides and to determine the relationship between its overexpression and HR-HPV infection. CPT and LB Pap test (LBPT) slides (165 samples of each) were examined by immunocytochemical staining for p16INK4a. After polymerase chain reaction (PCR), HPV-DNA was genotyped by dot blot hybridization. The CPT slides displayed more numerous dispersed squamous cells and LBPT slides had a clearer background. Positive p16INK4a on CPT occurred in 0% (0/30), 52.5% (21/40), 54.3% (19/35), 100% (30/30), and 100% (30/30) in normal, atypical squamous cells of undetermined significance (ASCUS), low-grade squamous intraepithelial lesions (LSILs), high-grade SILs (HSILs), and squamous cell carcinomas (SCCs) cases, respectively. LBPT slides showed comparable results but were less sensitive. HPV-DNA was detected in 86.7, 70, 45, 57.14, and 10% in SCCs, HSILs, ASCUS, LSILs, and normal cervical cells, respectively. Because HR-HPV was identified in all HPV+ samples of high-grade dysplasia (HSILs and SCCs) and all positive p16INK4a samples infected with HR-HPV, the association of p16INK4a overexpression with HR-HPV infection was confirmed. This study suggests that immunocytochemical staining of p16INK4a on CPT slides is convenient and cost-effective for cervical cancer screening by the detection of dysplastic cells infected with HR-HPV.

Presence and type of oncogenic human papillomavirus in classic and in differentiated vulvar intraepithelial neoplasia and keratinizing vulvar squamous cell carcinoma

The presence and type of oncogenic papillomavirus (HPV) in classic warty/basaloid vulvar intraepithelial neoplasia and in differentiated vulvar intraepithelial neoplasia and keratinizing vulvar squamous cell carcinoma was investigated using three techniques, that is, histology, in situ hybridization, and PCR-ELISA. HPV typing was performed using in situ hybridization and PCR-ELISA. Differentiated vulvar intraepithelial neoplasia and invasive keratinizing vulvar squamous cell carcinoma proved completely negative for HPV by PCR-ELISA, in situ hybridization, and histologic examination, while in classic vulvar intraepithelial neoplasia, a HPV positivity of 66.1% was found. HPV 16 was the predominant type, with HPV 35, 33, and 52 types found rarely and sometimes together with HPV 16. PCR-ELISA proved to be the most suitable method to detect and type mucosal oncogenic HPVs. The absolute absence of HPV DNA in differentiated vulvar intraepithelial neoplasias and in keratinizing vulvar squamous cell carcinoma suggests a strong HPV-independent pathway of malignant progression to invasive carcinoma.

High-throughput polymerase chain reaction chemiluminescent enzyme immunoassay for typing and quantifying human papillomavirus DNAs

A miniaturized polymerase chain reaction (PCR) chemiluminescent enzyme immunoassay (CLEIA) based on a 384-well microtiter plate for detection and typing of oncogenic high- and low-risk human papillomavirus (HPV) in genital lesions is described. The assay relies on PCR consensus amplification, hybridization of the digoxigenin-labeled product by means of type-specific biotin-labeled oligoprobes immobilized on the streptavidin-coated wells of a 384-well microtiter plate, and quantification by means of a horseradish peroxidase-labeled antidigoxigenin antibody and chemiluminescence detection. The method provides semiquantitative information on the viral load, with a limit of detection of 10-50 DNA copies for HPV 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 54, 58, and 59 and high reproducibility (intraassay CV 7.5%, interassay CV 9.5%). Results obtained on 60 clinical samples were concordant with those obtained with a conventional PCR-enzyme-linked immunosorbent assay colorimetric assay. The 384 PCR-CLEIA method, which is amenable to automation, represents a fast and high-throughput method for detecting and typing HPV DNAs in screening programs and evaluating the viral load.

Human papillomavirus viral load in predicting high-grade CIN in women with cervical smears showing only atypical squamous cells or low-grade squamous intraepithelial lesion

CONTEXT

Human papillomavirus (HPV) viral load may have an important role in predicting high-grade cervical intraepithelial neoplasia (CIN) in women with cervical smears showing atypical squamous cells or LSIL.

OBJECTIVE

To determine whether the assessment of the viral load of high-risk HPV DNA is useful in predicting the detection of high-grade cervical intraepithelial neoplasia (CIN2 and 3) in women referred because of cervical smears showing only atypical squamous cells or LSIL.

TYPE OF STUDY

Cross-sectional.

SETTING

Colposcopy Clinic in a University hospital.

METHODS

A series of 119 women referred because of atypical squamous cells or LSIL between August 2000 and April 2001 were included. All women were subjected to a new cervical smear, HPV testing for the high-risk types using hybrid capture II (HCII), viral load measurement in relative light units (RLU) and colposcopy, with cervical biopsies (n = 97). Cervical lesions were graded using the CIN classification.

RESULTS

Cervical biopsies revealed CIN2 or CIN3 in 11% of the cases, equally among women referred because of atypical squamous cells or LSIL. The HCII test was positive in 16% of women with atypical squamous cells and 52% of those with LSIL (OR = 5.8; 95% CI 1.4 to 26.7). There was strong correlation between CIN2 or CIN3 and positivity for HPV DNA when this group was compared with women with only CIN1 or normal cervix (OR = 7.8; 95% CI 1.5 to 53.4). In ROC analysis for HCII in diagnosing CIN2 and CIN3, the area under the ROC curve was 0.784, and the viral load cutoff point of 10.0 RLU/cutcuff presented 77% sensitivity and 73% specificity. Second cytology showing at least atypical squamous cells did not accurately detect CIN2 or CIN3 (OR = 6.4; 95% CI 1.0 to 50.9). The sensitivities of the second cervical smear and HCII were similar, although the specificity of HCII was significantly higher than the second cervical smear.

CONCLUSIONS

The viral load of high-risk HPV types was significantly associated with the diagnosis of CIN2 or CIN3 in women referred because of atypical squamous cells and LSIL abnormalities in their cervical smear.

Human papillomavirus testing methods

Testing for human papillomavirus (HPV) relies exclusively on techniques of molecular biology using nucleic acid probes. Tests for HPV using nucleic acid probes have been commercially available since the late 1980s, but early tests were cumbersome, involving the use of nucleic acid probes labeled with radioactive phosphorus (32P). These early HPV tests did not achieve widespread use because they did not detect all oncogenic HPV genotypes. The current commercial HPV detection kit, Digene's Hybrid Capture 2 kit, detects virtually all high-risk oncogenic HPV types, as well as most low-risk nononcogenic HPV genotypes. The Hybrid Capture 2 test format is a proprietary nucleic acid hybridization signal amplification system owned by Digene Corporation. Virtually all test formats for DNA sequence analysis are amenable to applications intended to detect and perhaps quantify the various HPV genotypes. These methods can involve direct hybridization with complementary DNA probes, such as Southern blotting or in situ hybridization, signal amplification, such as the Hybrid Capture 2 method or target nucleic acid amplification, most notably the polymerase chain reaction (PCR). Polymerase chain reaction has been used for HPV detection, genotyping, and viral load determination. General or consensus primer-mediated PCR assays have enabled screening for a broad spectrum of HPV types in clinical specimens using a single PCR reaction. Following amplification using consensus primers, individual HPV genotypes are identified using a variety of methods. Using consensus primers in a test format known as real-time quantitative PCR (RQ-PCR), it is possible to generate viral load (concentration) data from reaction curves generated by monitoring PCR reaction kinetics in real time.

Factors predicting human papillomavirus clearance in cervical intraepithelial neoplasia lesions treated by conization

OBJECTIVE

The objective was to identify the factors, if any, that may predict long-term results of CIN treatment and HPV clearance/persistence after locally excisional therapy.

METHODS

A series of 252 women with CIN lesions treated by conization were subjected to sequential HPV detection by repeated PCR during the prospective posttreatment follow-up. Factors predicting viral clearance during the follow-up (10.26 months) were elaborated using univariate and multivariate statistical techniques applied on epidemiological, clinical and biological data of the lesions.

RESULTS

Sensitivity of the PAP test in detecting high-grade lesions was 93.9%, and specificity 27.3%. Odds ratio for having CIN 3/Stage IA1 squamous cervical cancer in the cone with HSIL PAP test was 5.69; 77.8 and 22.2% residual disease were found among PCR-positive and -negative cases, respectively. HPV DNA was negative in 74/252 (29.8%) samples at the first PCR. Multivariate logistic regression analysis showed that HPV 16 was an independent explanatory factor for high-grade CIN (P = 0.0001). HPV clearance increased to 63.5% at completion of the follow-up, corresponding to the monthly clearance rate of 5.27%. In Kaplan-Meier analysis, the highly significant (P = 0.0001) predictors of HPV clearance/persistence were age, lesion grade in the biopsy, lesion grade in the cone, volume of the cone, length of active sexual life, and involvement of endocervical margin (P = 0.0013). In chi-square tests, high-risk HPV type (P = 0.001) was such a predictor. In multivariate (Cox) model, the significant independent predictors of HPV clearance were involved endocervical margin (P = 0.001), lesion grade in the cone (P = 0.004), high-grade lesion in the colposcopic biopsy (P = 0.023), age (P = 0.029), and HSIL in PAP smear (P = 0.029).

CONCLUSIONS

These data suggest that posttreatment follow-up should include both the PAP test and HPV detection techniques for early detection of any patients at increased risk for disease recurrence and progression, because of persistent oncogenic HPV types.

Human papillomavirus and cervical cancer

Of the many types of human papillomavirus (HPV), more than 30 infect the genital tract. The association between certain oncogenic (high-risk) strains of HPV and cervical cancer is well established. Although HPV is essential to the transformation of cervical epithelial cells, it is not sufficient, and a variety of cofactors and molecular events influence whether cervical cancer will develop. Early detection and treatment of precancerous lesions can prevent progression to cervical cancer. Identification of precancerous lesions has been primarily by cytologic screening of cervical cells. Cellular abnormalities, however, may be missed or may not be sufficiently distinct, and a portion of patients with borderline or mildly dyskaryotic cytomorphology will have higher-grade disease identified by subsequent colposcopy and biopsy. Sensitive and specific molecular techniques that detect HPV DNA and distinguish high-risk HPV types from low-risk HPV types have been introduced as an adjunct to cytology. Earlier detection of high-risk HPV types may improve triage, treatment, and follow-up in infected patients. Currently, the clearest role for HPV DNA testing is to improve diagnostic accuracy and limit unnecessary colposcopy in patients with borderline or mildly abnormal cytologic test results.

Microtiter Format for Simultaneous Multianalyte Detection and Development of a PCR-Chemiluminescent Enzyme Immunoassay for Typing Human Papillomavirus DNAs

Background: To allow multianalyte binding assays, we have developed a novel polystyrene microtiter plate containing 24 main wells, each divided into 7 subwells. We explored its clinical potential by developing a PCR-chemiluminescent immunoassay (PCR-CLEIA) for simultaneous detection and typing of seven high oncogenic risk human papillomavirus (HPV) DNAs in one well.

Methods: Seven different oligonucleotide probes, each specific for a high-risk HPV genotype, were separately immobilized in the subwells. Subsequently, a digoxigenin-labeled consensus PCR amplification product was added to the main well. The PCR product hybridized to the immobilized probe corresponding to its genotype and was subsequently detected by use of a peroxidase-labeled anti-digoxigenin antibody and chemiluminescence imaging with an ultrasensitive charge-coupled device camera. Results obtained for 50 cytologic samples were compared with those obtained with a conventional colorimetric PCR-ELISA.

Results: The method was specific and allowed detection of 50 genome copies of HPV 16, 18, 33, and 58, and 100 genome copies of HPV 31, 35, and 45. Intra- and interassay CVs for the method were 5.6% and 7.9%, respectively. All results obtained for clinical samples were confirmed by the conventional PCR-ELISA.

Conclusions: PCR-CLEIA allows rapid, single-tube simultaneous detection and typing of seven high-risk HPV DNAs with small reagent volumes. The principle appears applicable to the development of other single-tube panels of tests.

Human papillomavirus DNA testing by PCR-ELISA and hybrid capture II from a single cytological specimen: concordance and correlation with cytological results

BACKGROUND AND OBJECTIVES

A persistent infection by high-risk HPV is now considered as the major cause of cervical carcinoma. The use of a single cytological specimen for HPV DNA testing by two different molecular methods was analyzed and validated.

STUDY DESIGN

HPV DNA testing by PCR-ELISA and hybrid capture II HPV test (HC-II), was investigated on 317 cytological samples obtained from Italian women. Two hundred twenty-seven women were referred to virological lab for HPV DNA testing during cytological routine screening and 90 during a cytological and virological follow-up after a conization or hysterectomy.

RESULTS

Overall, the concordance between the two assays was high (K=0.87). Compared with PCR-ELISA, the HC-II showed a sensitivity of 91.7% and a specificity of 95.4%. Although the analytical sensitivity of the PCR-ELISA was higher, the performance of the two tests did not differ in recognizing HPV DNA positive patients with either low or high-grade squamous intraepithelial lesions (LSIL or HSIL). HPV DNA positivity was directly correlated with the severity of cytological diagnosis (P<0.005).

CONCLUSIONS

In view of the comparable results obtained with the two assays and of the ease of use, and higher throughput of HC-II, it seems advisable, with a single cytological specimen, to employ the HC-II test as a first-line assay, either for screening or diagnosis, and to perform reflex PCR on positive samples, if typing of prevalent high risk HPVs is needed.

Evaluation of commercial kits for the detection and typing of human papillomavirus in cervical swabs

Human papillomaviruses (HPV) detection by MY consensus primers amplification within the L1 region and typing of prevalent genital HPVs by reference and commercial sets of probes was compared by PCR-ELISA systems. The specificity of commercial probes used in the L1 HPV Geno-Kit with respect to the reference probes proved to be 100%, with an overall agreement of 97.6%. The discordant results concerned only the detection of HPV 16, both as single genotype present in the sample and as multiple infections. The analytical sensitivity of the commercial probe for HPV 16 proved to be slightly less sensitive than the reference probe in the hybridisation conditions of the PCR-ELISA system. The L1 PCR-ELISA reference system was evaluated further in comparison with commercial E6/E7 consensus PCR and microplate hybridisation by typing kit. Amplified products of both the L1 and E6/E7 consensus regions were also analysed by agarose gel electrophoresis. An overall concordance of 95.2% was found. On account of its specificity and sensitivity the E6/E7 commercial system proved to be particularly useful for diagnostic laboratory, as it detects only the prevalent high risk genotypes. The agarose gel detection can therefore be used as screening test, thus reducing the costs, while the E6 E7 HPV Geno-Kit High Risk can be used when specific typing is required.

Vaginal dysplastic lesions in women with hysterectomy and receiving radiotherapy are linked to high-risk human papillomavirus

Patients undergoing radiotherapy for advanced cervical and endometrial cancer bear a considerable risk of developing vaginal preneoplastic lesions. Radiotherapy itself has been considered to have a role in the pathogenesis of vaginal dysplasia, although human papillomavirus (HPV) involvement has also been suggested. A series of 88 patients who underwent hysterectomy and were irradiated for gynecological cancer, including 43 with postradiation vaginal dysplasia at colposcopy and 45 without vaginal lesions, were included in this study. Detection and genotyping of HPV DNA in vaginal scraping were carried out by a PCR-based method and compared with colposcopic and cytological findings and with other clinical and laboratory data. Forty-two (97.7%) colposcopy-positive subjects and 6 (13.3%) colposcopically-negative patients were PCR-positive for high-risk HPV DNA (P < 0.000001). Twenty-two out of the 43 patients with colposcopic lesions showed an abnormal Papanicolau (PAP) test. Cytologic examination was negative in all colposcopically negative women. Type 16 HPV DNA was more frequent in patients with high-grade squamous intraepithelial lesions and in patients treated with external radiotherapy, whereas other types of high-risk HPV were more common in patients with low-grade lesions and in those treated with brachytherapy. When considering colposcopy as the standard for diagnosing vaginal dysplasia, HPV DNA testing was more sensitive than the PAP test. However, the specificity of the PAP test was higher with no false-positive case. In conclusion, vaginal preneoplastic changes in women post-hysterectomy and receiving radiotherapy for cervical, endometrial, and vaginal cancer represent an HPV-related nosologic entity. Whereas colposcopic examination can detect these preneoplastic lesions, HPV genotyping is a sensitive, inexpensive, and noninvasive method that may complement colposcopy and the PAP test.