Viral load of episomal and integrated forms of human papillomavirus type 33 in high-grade squamous intraepithelial lesions of the uterine cervix

The association between total and integrated HPV-33 DNA loads and high-grade squamous intraepithelial lesions (HSIL) of the uterine cervix was investigated. Of 5,347 women recruited in 4 studies, 89 (64 without SIL, 7 low-grade SIL (LSIL), 15 HSIL, 3 unknown grade) were infected by HPV-33. HPV-33 E6, HPV-33 E2 and beta-globin DNA were measured with real-time PCR that allowed to assess total (E6), episomal (E2) and integrated (E6-E2) HPV-33 viral loads. HPV-33 E6/E2 ratios >/=>/=2.0 suggesting the presence of integrated HPV-33 were obtained for 28.6% (n = 18) of women without SIL and 21.4% (n = 3) of women with HSIL (p = 0.74). Although median viral loads were similar, there was a trend toward having a greater proportion of women with HSIL in the fourth quartile (>/=>/=10(6.69) copies/mug DNA) of total HPV-33 viral loads compared to normal women. Controlling for age, site, ethnicity and LCR polymorphism by logistic regression, HPV-33 total loads in the fourth quartile {odds ratio (OR) 4.5 [95% confidence interval (CI) 1.2-17.3]; p = 0.03} and episomal loads in the fourth quartile (>/=>/=10(6.64) copies/mug DNA) [OR 3.9 (95% CI 1.1-13.2); p = 0.05] but not integrated HPV-33 load in the fourth quartile [OR 1.0 (95% CI 0.3-3.3); p = 0.50] were associated with HSIL. Controlling for age, study site and SIL grade, HPV-33 episomal load [OR 0.2 (95% CI 0.1-0.5), p = 0.0004] was associated with the presence of HPV-33 integration. High episomal loads in HSIL and the presence of integration in women without SIL are likely to weaken the usefulness of HPV load of integrated forms in clinical practice.     

Characterization of HPV genotype profile in squamous cervical lesions in Portugal, a southern European population at high risk of cervical cancer.

A different prevalence of human papillomavirus (HPV) types has been reported in distinct populations. Although Portugal has a relatively high incidence of cervical cancer within the European Union, no studies have been reported in the Portuguese population. Recently, a clinical trial using a vaccine targeted against HPV-16 demonstrated a high efficacy in preventing HPV-16 cervical lesions. The aim of the present study was the characterization of HPV genotype profile in squamous intraepithelial lesions (SIL) and invasive cervical cancer (ICC) from 608 patients using polymerase chain reaction (PCR) methodology. We frequently detected HPV-6/11 and HPV-16 in low-grade SIL (HPV-6/11, 18.9%; HPV-16, 44.2%). In high-grade SIL, HPV-16 was demonstrated in 74.2% of those lesions and in 80.0% of the cases with ICC. HPV-18 was found in 3.1%, 0.8% and in 15.0% of low, high SIL and ICC, respectively. The overall prevalence of multiple infections with high-risk HPV was 7.2%. Other types of HPV were detected in 7.0% of all cases. Our results demonstrate a high prevalence of HPV-16 in SIL and ICC in Portuguese women. Therefore, a prophylactic HPV-16/18 vaccine may be effective in the prevention of cervical cancer in a significant number of women from this southern European population.     

Comparative analysis of human papillomavirus detection by hybrid capture assay and routine cytologic screening to detect high-grade cervical lesions

A commercial HPV detection test, Hybrid Capture (HC), designed to detect 14 HPV types divided into high-risk and low-risk groups, has been evaluated. A total of 1064 scrapes from 1028 unselected women attending routine cytologic screening were tested and results were compared with those of classic cytologic screening and cervical biopsies. The reliability of the test was also evaluated on 38 fresh conization samples. HPV DNA was detected in 108 women (10.5%), including 90 infected by a high-risk HPV (8.8%); 25 high-grade lesions were detected histologically, and high-risk HPV was found in 16 of these 25 women (64%), and in 27 (71%) of the 38 conization samples. The overall sensitivity of HC in detecting high-grade SIL on cervical scrapes and conization samples was 71.2%, while its positive predictive value was 17.8%. Classic cytologic screening appeared to be the most sensitive method (84%) for detecting high-grade SIL, with a positive predictive value of 91.3%. The lower sensitivity of HC limits its use for screening high-grade lesions on a large scale, even though it may be useful for reducing cytologically false-negative results. Moreover, the quantitative approach provided by the HC assay for assessment of the viral load cannot clearly distinguish among cases with or without high-grade lesions. Int. J. Cancer 75:525–528, 1998.© 1998 Wiley-Liss, Inc.     

Cross-sectional analysis of oncogenic HPV viral load and cervical intraepithelial neoplasia

In human papillomavirus (HPV)-associated carcinogenesis, HPV infection characteristics such as viral load may play an important role in lesion development. The purpose of this study was to determine the association between quantitative assessment of oncogenic HPV viral load, and abnormal cytology among women residing along the United States-Mexico border. A cross-sectional study of 2,319 women was conducted between 1997 and 1998. Viral load of oncogenic HPV types (16, 18, 31, 39, 45, 51, 52, and 58) was measured among 173 HPV (+) women using quantitative real-time PCR. Overall, HPV 16, 31, 52 and 58 showed the highest viral load. Single type infection had higher viral loads compared to multiple type infections. HPV viral load declined significantly (p = 0.04) with age. No significant association was observed with other known HPV risk factors such as oral contraceptive use, parity, sexual and STD history. Viral load was independently associated with degree of cervical lesions. An adjusted odds ratio (AOR) of 4.7 for the association between increasing total viral load and Atypical Squamous Cells of Undetermined Significance (ASCUS)/Atypical Glandular Cells of Undetermined Significance (AGUS) was observed (p for trend <0.01). Increased risk of low-grade SIL was observed with higher viral load compared with HPV negative women (AOR = 47.7 for total viral load; AOR = 37.1 for HPV viral load not including HPV16, and AOR = 25.9 for HPV16 viral load). Likewise, increased risk of high-grade SIL with higher viral loads was observed (AOR = 58.4 for high total viral load compared with HPV negative women, AOR = 58.1 for HPV viral load not including HPV16, and AOR = 69.8 for HPV16 high viral load). Results from this study suggest a dose-response relationship between increasing oncogenic HPV viral load and risk of LSIL and HSIL.     

Human papillomavirus infections with multiple types and risk of cervical neoplasia.

BACKGROUND: Besides an established role for certain human papillomavirus (HPV) genotypes in the etiology of cervical cancer, little is known about the influence of multiple-type HPV infections on cervical lesion risk. We studied the association between multiple HPV types and cervical lesions among 2,462 Brazilian women participating in the Ludwig-McGill study group investigation of the natural history of HPVs and cervical neoplasia. METHODS: Cervical specimens were typed by a PCR protocol. The cohort's repeated-measurement design permitted the assessment of the relation between the cumulative and concurrent number of HPV types and any-grade squamous intraepithelial lesions (SIL) and high-grade SIL (HSIL). RESULT: At individual visits, 1.9% to 3.2% of the women were infected with multiple HPVs. Cumulatively during the first year and the first 4 years of follow-up, 12.3% and 22.3% were infected with multiple types, respectively. HSIL risk markedly increased with the number of types [odds ratio (OR), 41.5; 95% confidence interval (95% CI), 5.3-323.2 for single-type infections; OR, 91.7; 95% CI, 11.6-728.1 for two to three types; and OR, 424.0; 95% CI, 31.8-5651.8 for four to six types, relative to women consistently HPV-negative during the first year of follow-up]. The excess risks for multiple-type infections remained after exclusion of women infected with HPV-16, with high-risk HPV types, or persistent infections, particularly for any-grade SIL. Coinfections involving HPV-16 and HPV-58 seemed particularly prone to increase risk. CONCLUSION: Infections with multiple HPV types seem to act synergistically in cervical carcinogenesis. These findings have implications for the management of cervical lesions and prediction of the outcome of HPV infections.     

Human papillomaviral load changes in low-grade squamous intraepithelial lesions of the uterine cervix

To better predict risk of progression of low-grade squamous intraepithelial lesions (LSILs) of the uterine cervix in women with human papillomavirus (HPV) infections, 294 baseline cervical specimens from women with LSILs were evaluated. Specimens were tested for HPV DNA using hybrid capture 2 (HC2) and PCR-reverse line blotting. 65 LSILs with HPV DNA types 16, 18, 52, or 58 were examined for physical status, E2/E6 ratio and viral load at two time points, along with patient age. Women with LSILs whose viral loads increased between baseline and 6 month follow-up had a 45% risk of developing HSIL (OR=7.6, 95% CI=1.9-29.4, P<0.01), as evaluated by real-time PCR and a 44% risk (OR=6.1, 95% CI=1.6-22.7, P<0.01), as evaluated by HC2. The two viral load measures correlated well (Person's coefficient, r=0.687, P<0.001). Such evaluations of viral load changes (increased or not increased) through repeat HPV DNA testing could predict progression of disease in LSIL cases of HPV types 16, 18, 52, and 58, which correlates to clinical implications.     

High load for most high risk human papillomavirus genotypes is associated with prevalent cervical cancer precursors but only HPV16 load predicts the development of incident disease

Cervicovaginal human papillomavirus (HPV) viral load has been purported as a potential marker for the detection of high-grade cervical intraepithelial neoplasia or cancer (>/=CIN2). To examine disease association with type-specific viral load for the full-range of anogenital HPV infections, we conducted cross-sectional and prospective analyses of approximately 2,000 HPV-infected women from a 10,000-woman population-based study in Guanacaste, Costa Rica with 7 years of follow-up. Cervical specimens were tested for >40 HPV types using a MY09/MY11 L1 consensus primer PCR method with type-specific dot blot hybridization and PCR signal intensity as a measure of viral load. A positive association was observed between prevalent >/=CIN2 and high viral load compared to low viral load for women with baseline single HPV16 infections (OR = 19.2, 95% CI = 4.4-83.2) and single non-16 carcinogenic infections (OR = 9.2, 95% CI = 2.1-39.9). Inclusion of women with multiple HPV types did not substantially change these associations. In prospective follow-up, only women infected with HPV16 alone (OR = 27.2, 95% = 3.5-213.5) had a strong association between high viral load and incident >/=CIN2; non-16 carcinogenic high viral load was not associated with incident >/=CIN2 (OR = 0.7, 95% CI = 0.2-1.9). Single noncarcinogenic type viral load was not associated with increased risk of prevalent or incident >/=CIN2 (OR = 1.2 and 1.1, respectively). In conclusion, carcinogenic high viral load was associated with prevalent >/=CIN2; however HPV16 was uniquely associated with incident >/=CIN2. The extent to which these observations can be translated into clinical practice must be rigorously examined in the context of the method of viral load measurement and the type-specific differences observed for incident >/=CIN2.     

A comprehensive natural history model of HPV infection and cervical cancer to estimate the clinical impact of a prophylactic HPV-16/18 vaccine

The object of our study is to project the impact of a prophylactic vaccine against persistent human papillomavirus (HPV)-16/18 infection on age-specific incidence of invasive cervical cancer. We developed a computer-based mathematical model of the natural history of cervical carcinogenesis to incorporate the underlying type-specific HPV distribution within precancerous lesions and invasive cancer. After defining plausible ranges for each parameter based on a comprehensive literature review, the model was calibrated to the best available population-based data. We projected the age-specific reduction in cervical cancer that would occur with a vaccine that reduced the probability of acquiring persistent infection with HPV 16/18, and explored the impact of alternative assumptions about vaccine efficacy and coverage, waning immunity and competing risks associated with non-16/18 HPV types in vaccinated women. The model predicted a peak age-specific cancer incidence of 90 per 100,000 in the 6th decade, a lifetime cancer risk of 3.7% and a reproducible representation of type-specific HPV within low and high-grade cervical precancerous lesions and cervical cancer. A vaccine that prevented 98% of persistent HPV 16/18 was associated with an approximate equivalent reduction in 16/18-associated cancer and a 51% reduction in total cervical cancer; the effect on total cancer was attenuated due to the competing risks associated with other oncogenic non-16/18 types. A vaccine that prevented 75% of persistent HPV 16/18 was associated with a 70% to 83% reduction in HPV-16/18 cancer cases. Similar effects were observed with high-grade squamous intraepithelial lesions (HSIL) although the impact of vaccination on the overall prevalence of HPV and low-grade squamous intraepithelial lesions (LSIL) was minimal. In conclusion, a prophylactic vaccine that prevents persistent HPV-16/18 infection can be expected to significantly reduce HPV-16/18-associated LSIL, HSIL and cervical cancer. The impact on overall prevalence of HPV or LSIL, however, may be minimal. Based on the relative importance of different parameters in the model, several priorities for future research were identified. These include a better understanding of the heterogeneity of vaccine response, the effect of type-specific vaccination on other HPV types and the degree to which vaccination effect persists over time.     

Determination of viral load thresholds in cervical scrapings to rule out CIN 3 in HPV 16, 18, 31 and 33-positive women with normal cytology

An increased high-risk human papillomavirus (hrHPV) viral load in cervical scrapings has been proposed as a determinant for high-grade cervical intraepithelial neoplasia (CIN) and cervical cancer (> or =CIN 2), but data so far for HPV types different from HPV 16 are limited and inconsistent. In addition, a viral load threshold to distinguish hrHPV positive women without > or =CIN 2 still has not been defined. Here, we used baseline cervical scrapings of women with normal cytology participating in a large population-based cervical screening trial (i.e. POBASCAM) who were GP5+/6+-PCR positive for 4 common hrHPV types, i.e. HPV 16, 18, 31 or 33, as a reference to arbitrarily define various viral load thresholds (i.e. 25th, 33rd, 50th, 67th and 75th percentiles of the lowest viral load values) for distinguishing women having single infections with these types without high-grade CIN. Viral load assessment was performed by real time type-specific PCR. The viral load threshold values were subsequently validated on abnormal cervical scrapes of 162 women with underlying, histologically confirmed CIN lesions containing 1 of these 4 hrHPV types. All 59 women with CIN 3 had viral load levels that were higher than those of 33% of the women with normal cytology containing the respective hrHPV type detectable by GP5+/6+-PCR (i.e. higher than the 33rd percentile of viral load). By using this 33rd percentile viral load cut-off, sensitivity for CIN 3 of 100% (95% CI 93.9-100) was obtained. Hence, application of this viral load threshold would increase the specificity of HPV testing for HPV 16, 18, 31 and 33-associated prevalent CIN 3 without the cost of a marked reduction in sensitivity. In practice, on the basis of viral load analysis, a less aggressive management can be foreseen for 33% of the women with normal cytology participating in a population-based screening program who are GP5+/6+-PCR positive for HPV 16, 18, 31 or 33.     

Distribution and prevalence of human papillomavirus genotypes in routine pap smear of 2,470 korean women determined by DNA chip.

PURPOSE: We examined human papillomavirus (HPV) genotype distribution and prevalence from routine Pap smear cases in Korean women using DNA Chip.Patients and METHODS: A total of 2,470 cervical specimens from women attending routine Pap smear cytology screening in local hospitals was subjected to HPV test. HPV detection and genotyping were done using DNA Chip.RESULTS: HPV DNA was detected in 44.8% of the patients and in 58.7% of the 861 atypical lesions based on the Bethesda system, including 52.6% of 627 atypical squamous cells of undetermined significance (ASCUS), 69.0% of 168 low-grade squamous intraepithelial lesions (LSIL), and 89.4% of 66 high-grade squamous intraepithelial lesions (HSIL) cases. The most frequently found genotypes in all HPV-positive cases were HPV-16, HPV-52, and HPV-58. HPV-16 was the most prevalent type in within normal limits, ASCUS, and HSIL categories, whereas HPV-51 was most frequently found in LSIL. Multiple infection was identified in about 20% of HPV-positive cases and most of them were that by two different types. HPV-16 was present in the majority of multiple infection cases. A significant decrease in the percentage of multiple infection was observed in HSIL cases compared with ASCUS and LSIL.CONCLUSIONS: The distribution of HPV genotypes in Korean women was revealed to have differences to that of other regions, showing higher frequencies of HPV-52, HPV-58, and HPV-51. HSIL cases were mostly infected by sole HPV-16 whereas LSIL that by various HPV types, suggesting a certain type may become dominant over others as the disease progresses.     

Semiquantitative human papillomavirus type 16 viral load and the prospective risk of cervical precancer and cancer.

We examined whether higher human papillomavirus type 16 (HPV16) viral load predicted risk of cervical intraepithelial neoplasia 3 (CIN3) or cancer (together termed > or =CIN3) within a cohort of 20,810 women followed for 10 years with cytologic screening. Semiquantitative viral load for HPV16 was measured on baseline cervicovaginal specimens using a type-specific hybridization probe test with signal amplification. An increased risk of > or =CIN3 associated with higher HPV16 viral load was found only among cytologically negative women in early follow-up, suggesting that these cases were related to the detection of prevalent lesions missed at baseline. Women with higher HPV16 viral load were more likely to undergo ablative treatment during follow-up than those with lower viral load (P(trend) = 0.008), possibly diminishing any additional risk for > or =CIN3 attributable to higher HPV16 viral loads.     

The natural history of type-specific human papillomavirus infections in female university students.

Little is known about the average duration of type-specific human papillomavirus (HPV) infections and their patterns of persistence. The objectives of this study were to evaluate the rate of acquisition and clearance of specific HPV types in young women. Female university students (n = 621) in Montreal were followed for 24 months at 6-month intervals. At each visit, a cervical specimen was collected. HPV DNA was detected using the MY09/MY11 PCR protocol followed by typing for 27 HPV genotypes by a line blot assay. The Kaplan-Meier technique was used to estimate the cumulative probability of acquiring or clearing a HPV infection considering types individually or in high-risk (HR) or low-risk (LR) groups defined by oncogenic potential. Incidence rates were 14.0 cases/1000 women-months (95% confidence interval, 11.4-16.3) and 12.4 cases/1000 women-months (95% confidence interval, 10.4-14.8) for acquiring HR and LR HPV infections, respectively. The 24-month cumulative rates of acquisition were highest for HPV-16 (12%), HPV-51, and HPV-84 (8%). Of the incident infections, HPV-16 was the most persistent (mean duration, 18.3 months), followed by HPV-31 and HPV-53 (14.6 and 14.8 months, respectively). HPV-6 and HPV-84 had the shortest mean duration time (<10 months) The mean durations of incident, same-type LR or HR HPV infections were 13.4 months and 16.3 months, respectively. Whereas the majority of episodes with a type-specific HPV infection cleared within 2 years, there were many women who were either reinfected with a new HPV genotype or presumably experienced reactivation of their initial infection.     

Host and viral factors in relation to clearance of human papillomavirus infection: a cohort study in Taiwan

Human papillomavirus (HPV) persistence is essential for cervical cancer development. We accrued nested-cohort subjects from a population-based study to investigate the host and viral factors related to outcome of HPV infection. Women (age > or = 30 years old) with HPV-positive but normal cytology and negative colposcopy were invited to participate. After signing informed consent, every participant completed a structured questionnaire and had 6-monthly follow-ups of Pap smear, HPV testing and colposcopy. Total and type-specific HPV clearance rates as well as host and viral factors associated with clearance in 3-year longitudinal follow-up were analyzed. Adjusted hazard ratios (HRs) of progression to > or = cervical intraepithelial neoplasia (CIN) 2 according to baseline HPV of the women with normal cytology were calculated from national registry database. Among the 626 eligible women, 526 (median age 47, 29-75) were enrolled and 412 returned for follow-up at least once. The median follow-up of enrolled subjects was 23 months (range 6.8-39). The 3-year cumulative total HPV clearance rate was 49.0% (95% confidence interval [CI]: 43.3-54.7%). The median 3-year cumulative type-specific HPV clearance rate was 50.0% (range 0-100.0%) with a median time to clearance of 12.4 months (6.4-24.5). Older age was associated with significantly decreased total HPV clearance and decreased type-specific clearance in HPV-18 and -53, while high viral load was associated with decreased total and type-specific clearance. After adjusting confounding variables, the HR of developing > or =CIN2 in baseline HPV-positive women was 34.0-fold (95% CI: 15.5-74.7) as compared to HPV-negative women.     

Human papillomavirus types in 115,789 HPV-positive women: A meta-analysis from cervical infection to cancer

Genotyping may improve risk stratification of high-risk (HR) human papillomavirus (HPV)-positive women in cervical screening programs; however, prospective data comparing the natural history and carcinogenic potential of individual HR types remain limited. A meta-analysis of cross-sectional HR HPV-type distribution in 115,789 HPV-positive women was performed, including 33,154 normal cytology, 6,810 atypical squamous cells of undetermined significance (ASCUS), 13,480 low-grade squamous intraepithelial lesions (LSIL) and 6,616 high-grade SIL (HSIL) diagnosed cytologically, 8,106 cervical intraepithelial neoplasia grade 1 (CIN1), 4,068 CIN2 and 10,753 CIN3 diagnosed histologically and 36,374 invasive cervical cancers (ICCs) from 423 PCR-based studies worldwide. No strong differences in HPV-type distribution were apparent between normal cytology, ASCUS, LSIL or CIN1. However, HPV16 positivity increased steeply from normal/ASCUS/LSIL/CIN1 (20-28%), through CIN2/HSIL (40/47%) to CIN3/ICC (58/63%). HPV16, 18 and 45 accounted for a greater or equal proportion of HPV infections in ICC compared to normal cytology (ICC:normal ratios = 3.07, 1.87 and 1.10, respectively) and to CIN3 (ICC:CIN3 ratios = 1.08, 2.11 and 1.47, respectively). Other HR types accounted for important proportions of HPV-positive CIN2 and CIN3, but their contribution dropped in ICC, with ICC:normal ratios ranging from 0.94 for HPV33 down to 0.16 for HPV51. ICC:normal ratios were particularly high for HPV45 in Africa (1.85) and South/Central America (1.79) and for HPV58 in Eastern Asia (1.36). ASCUS and LSIL appear proxies of HPV infection rather than cancer precursors, and even CIN3 is not entirely representative of the types causing ICC. HPV16 in particular, but also HPV18 and 45, warrant special attention in HPV-based screening programs.     

Immunoglobulin-A and -G responses against virus-like particles (VLP) of human papillomavirus type 16 in women with cervical cancer and cervical intra-epithelial lesions

Immunoglobulin-A and -G (IgA and IgG) responses against HPV-16-like particles (VLP) were tested by ELISA in 104 women with cervical abnormalities, 26 atypical cells of undetermined significance (ASCUS) and 14 cytologically normal women with HPV DNA. As controls, 130 age-matched cytologically normal women with no HPV DNA were selected from the population in which the cases were generated. The existence of HPV DNA in cervical samples was tested by a PCR-based method. The normal women positive with HPV16 DNA were followed up at 4- to 7-month intervals for 16 to 24 months. IgA and IgG antibodies against HPV-16 VLP were frequently detected in these women repeatedly positive with HPV-16 DNA, suggesting that persistent HPV infection is crucial for effective antibody responses against the viruses. IgA response appears earlier and persists longer than IgG response. Women with HPV DNA of types 16, 31/33/35, 58 and unknown types showed significantly higher seropositivity for both IgA and IgG antibodies than the controls (p < 0.05 for both). No significant seropositivity for IgA or IgG was detected in the HPV-18/45-DNA-positive group. HPV 31/33/35, 58 appear to be types close to HPV 16, whereas HPV 18/45 appears to be distinct from HPV 16 in antigenicity. IgA and IgG responses against HPV-16 VLP were more frequently observed in women with normal cervices with HPV DNA, ASCUS, HSIL and cervical cancer than in the controls. Strong IgA and IgG responses depended on HPV-16 infection in HSIL and cervical cancer, but there was no correlation between the serological responses and the status of HPV DNA in ASCUS and LSIL. Antibody positivity reflects persistent viral infection that may increase the risk for malignant progression of the cervix. This serological assay using HPV 16-VLP may therefore be useful as a new diagnostic tool supplementing cervical cytological tests. Int. J. Cancer 75:529–535, 1998.© 1998 Wiley-Liss, Inc.     

Performance of HPV DNA Testing with Hybrid Capture 2 in Triaging Women with Minor Cervical Cytologic Abnormalities (ASC-US/LSIL) in Northern Thailand

Background: Minor cervical cytologic abnormalities include atypical squamous cells of undeterminedsignificance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL). Approximately 10-20% of womenwith minor cytologic abnormalities have histologic high-grade squamous intraepithelial or worse lesions (HSIL+).In Thailand, women with minor cytologic abnormalities have a relatively high risk of cervical cancer, and referralfor colposcopy has been suggested. A triage test is useful in the selection of women at risk for histologic HSIL+ toreduce the colposcopy burden. The aim of this study was to assess the performance of high-risk HPV DNA test intriage of women with minor cytologic abnormalities in northern Thailand. Materials and Methods: All womenwith ASC-US/LSIL cytology who were referred to our colposcopy clinic from October 2010 to February 2014were included. HPV DNA testing was performed using Hybrid Capture 2 (HC2). All patients received colposcopicexamination. Accuracy values of HC2 in predicting the presence of histologic HSIL+ were calculated. Results:There were 238 women in this study (121 ASC-US and 117 LSIL). The HC2 positivity rate was significantlyhigher in the LSIL group than in ASC-US group (74.8% versus 41.0%, p<0.001). Histologic HSIL+ was detectedin 9 women (7.4%) in the ASC-US group and 16 women (13.7%) in the LSIL group (p=0.141). There was nohistologic HSIL+ detected among HC2-negative cases (sensitivity and negative predictive value of 100%). Theperformance of HC2 triage was highest among women aged >50 years with ASC-US cytology. An increase in thecut-off threshold for positive HC2 resulted in a substantial decrease of sensitivity and negative predictive value.Conclusions: HPV DNA testing with HC2 shows very high sensitivity and negative predictive value in triage ofwomen with minor cervical cytologic abnormalities in northern Thailand. An increase of the cut-off thresholdfor HC2 triage is not recommended in this region.     

Human Papilloma Virus Genotype Distribution in Cervical lesions in Zanjan,Iran

Objective: Cervical cancer is one of the most common cancers among women all over the world, and main cause is persistent infection with high risk human papillomavirus (HPV) strains. It has been reported that the distribution and prevalence of HPV types varies by geographical region, so that this is important for prevention by type-specific vaccines. The aim of current study was to determine the genotype distribution of HPV using the INNO-LiPA genotyping assay in Zanjan province, North West Iran. Methods: A total of 112 formalin-fixed paraffin embedded (FFPE) tissue samples from cases of low-grade intraepithelial lesion (LSIL), high-grade intraepithelial lesion (HSIL) and squamous cell carcinoma (SCC) were collected. The polymerase chain reaction (PCR) was used to amplify DNA for genotyping. Results: Among the 112 samples from females (ranging from 20 to 69 years, mean age 43.8 ± 10.1) tested for HPV DNA, 50 samples were positive. Based on results of genotyping, most common HPV genotypes were HPV18 (48%) followed by HPV-6 (24%), HPV73 (16%), HPV-51(8%), HPV-31(8%), HPV-16 (8%), HPV-56 (4%), HPV-44 (4%). Conclusion: While HPV infection is the major etiological factor for cervical cancer, presence was relatively low in our survey. In the positive cases, however, HPV18 was the most common in line with many other populations. The fact that types vary among different populations must clearly be taken into account in design of vaccines for our country.     

Quantitative methylation-specific PCR for the detection of aberrant DNA methylation in liquid-based Pap tests

BACKGROUND: Aberrant promoter methylation of selective tumor suppressor genes has been detected in squamous intraepithelial lesions (SIL) and invasive cervical cancer. Identification of methylation profiles of genes that can distinguish high-grade SIL (HSIL) from low-grade SIL (LSIL), and cytologically negative for intraepithelial lesion or malignancy (NILM) residual liquid-based Papanicolaou (Pap) tests may be potentially useful as an ancillary test for cervical cancer screening. METHODS: Using real-time quantitative methylation-specific polymerase chain reaction (PCR) (QMSP), the authors analyzed the frequency and relative level of promoter methylation for DAPK1, IGSF4, SPARC, and TFPI2 in biopsy-confirmed HSIL and LSIL, and NILM residual liquid-based Pap tests. The percentage of methylation (%M) for each gene was calculated using the reference gene, ACTB. The cumulative methylation score for each sample, defined as the sum of %M of all 4 genes, was used to analyze the genes in combination. RESULTS: For each gene analyzed the frequency and relative level of methylation were increased in HSIL compared with combined NILM/LSIL samples. The cumulative methylation scores were significantly higher in HSIL samples (P < .0001). Area under the receiver operating characteristic (ROC) curve (AUC) demonstrated that methylation of each gene could distinguish HSIL from NILM/LSIL samples (AUC range, 0.6-0.67; P < or = .0028). The combination of 4 genes showed improved test performance (AUC = 0.76; P < .0001). There was no significant difference in cumulative methylation in HSIL cases with histologic outcomes of cervical intraepithelial neoplasia grade 2 (CIN2) versus CIN3. There was no association between the methylation of any gene and the presence of human papillomavirus. CONCLUSIONS: The methylation profile of multiple genes in combination can better distinguish HSIL from combined NILM/LSIL samples. Although aberrant DNA methylation has the potential to function as a molecular biomarker of HSIL in liquid-based Pap tests, additional genes that are selectively methylated in HSIL are needed to improve the clinical performance.     

Prevalence, acquisition, and clearance of cervical human papillomavirus infection among women with normal cytology: Hawaii Human Papillomavirus Cohort Study

Few natural history studies of cervical human papillomavirus (HPV) incidence and duration have been conducted among older women, especially from multiethnic populations. Viral and nonviral determinants of HPV acquisition and clearance were examined among 972 sexually active women, ages 18 to 85 years, recruited from clinics on Oahu, Hawaii, and followed for a mean duration of 15 months (range, 2-56 months). Interviews and cervical cell specimens for cytology and HPV DNA detection by PCR, using the PGMY09/PGMY11 primer system, were obtained at baseline and at 4-month intervals. The prevalence of cervical HPV infection was 25.6% at study entry. A total of 476 incident genotype-specific infections were observed during the follow-up period. The incidence of high-risk (HR) HPV types (9.26 per 1,000 woman-months) was similar to low-risk (LR) HPV types (8.24 per 1,000 woman-months). The most commonly acquired HR-HPV types were HPV-52, HPV-16, and HPV-31; and their incidence was increased significantly with a coexisting cervical HPV infection. Cervical HPV acquisition decreased with age, income, and long-term use of oral contraceptives and increased with number of sexual partners, use of hormonal creams, alcohol drinking, and condom use by a sexual partner. Cohort participants cleared 265 of the 476 incident infections during follow-up. LR-HPV infections cleared more rapidly than did HR-HPV infections (median, 180 days versus 224 days). Clearance times were enhanced among older women and women with multiple infections. Our data suggest several viral and nonviral determinants of cervical HPV acquisition and clearance that might be used in cervical cancer prevention programs.     

Physical state and viral load as predictive biomarkersfor persistence and progression of HPV16-positive cervical lesions: results from a population based long-term prospective cohort study

Persistent infection with a high risk (hr) human papillomavirus (HPV) has been established as the main cause of cervical cancer and high-grade cervical intraepithelial neoplasia (CIN3). Because most infections are transient, testing for hrHPV lacks specificity and has a low positive predictive value. It has been suggested that additional parameters like viral load and physical status of the viral genome could improve the effectiveness of HPV-based screening. We investigated the association between HPV16 viral load and physical state with viral persistence or risk of incident CIN3 or worse in a population-based prospective cohort study comprising 8656 women (20-29 years). All participants had two gynecological examinations two years apart and were followed through the nationwide Danish Pathology Data Bank (median follow-up: 12.9 yrs). Seventynine cervical swabs from women with a persistent HPV16 infection were available for analysis. For comparison we selected a random age-matched sample of transiently HPV16 infected women (N=91). Persistently infected women with incident CIN3 or cancer (CIN3+; N=31) were compared to women with normal cytology during follow up (non-progressors; N=39). Quantitative real-time PCR for HPV16E6, E2 and IFNb1 was done to determine the HPV16 viral load and the E2/E6 ratio was used as a surrogate marker for integration. Women with normal cytology who became persistently HPV16 infected had a significantly lower HPV16 load at baseline than women who cleared the infection (median 4.72 copies/cell versus median 20.0 copies/cell, respectively; p=0.0003). There was no difference in viral load at enrollment between women who progressed to CIN3+ and women who stayed cytologically normal (p=0.85). At the second examination viral load tended to be higher in women who progressed, but the difference was not statistically significant (p=0.39). The E2/E6 ratio was shown to be lower in the persistently infected group (p<0.0001) already at the first examination, but no difference between non-progressors and CIN3+ cases was observed at any of the two examinations (p=0.61 and 0.86). Lower viral load and integration of the viral genome are predictive for the persistence of HPV16 DNA, but not for the progression of a persistent HPV16 infection to CIN3+ in women with normal cytology.