Human papillomavirus-type persistence patterns predict the clinical outcome of cervical intraepithelial neoplasia

Evaluation of CD4+ cells infiltration as a prognostic factor in cervical intraepithelial neoplasia 2

OBJECTIVE

To identify candidate predictors for the prognosis of cervical intraepithelial neoplasia 2 (CIN2) lesions and evaluate the prognostic value of the local immune response.

METHODS

One hundred fifteen CIN2 patients were enrolled. The percentage of p16-, minichromosome maintenance complex component 2- or apolipoprotein B mRNA editing enzyme catalytic subunit 3G (APOBEC3G)-positive cells was determined immunohistochemically. Tumor-infiltrating lymphocytes (TILs) in intertumoral lesions were scored using an automated system. CIN3 disease progression and regression rates were estimated by the Kaplan-Meier method. A case-control study was conducted to screen CIN2 prognostic factors in 10 regression and 10 progression patients. Selected factors were examined in a cohort study to determine their prognostic value for CIN2.

RESULTS

Among all participants, the cumulative progression and regression rates at 60 months were 0.477 and 0.510, respectively. In the case-control study, p16- and APOBEC3G-positive cells were higher in the progression group (p=0.043, p=0.023). Additionally, CD4⁺ cell infiltration was enhanced in the regression group (p=0.023). The cohort study revealed a significantly increased progression rate in patients with elevated p16-positive cells (p<0.001), and increased CD4⁺ TIL infiltration was associated with better regression (p=0.011). Kaplan-Meier analysis according to human papillomavirus (HPV) positivity revealed a greater CIN3 development risk in HPV16-positive patients than in HPV16-negative cases. Finally, multivariate analysis identified HPV16 infection and CD4⁺ TIL infiltration as independent prognostic factors in CIN2 regression.

CONCLUSION

CD4⁺ TIL infiltration in intertumoral lesions was related with CIN2 regression. Our findings suggest CD4⁺ TIL infiltration may be useful for the triage of CIN2 patients.

False Negative Results in Cervical Cancer Screening-Risks, Reasons and Implications for Clinical Practice and Public Health

False negative (FN) results in cervical cancer (CC) screening pose serious risks to women. We present a comprehensive literature review on the risks and reasons of obtaining the FN results of primary CC screening tests and triage methods and discuss their clinical and public health impact and implications. Misinterpretation or true lack of abnormalities on a slide are the reasons of FN results in cytology and p16/Ki-67 dual-staining. For high-risk human papillomavirus (HPV) molecular tests, those include: truly non-HPV-associated tumors, lesions driven by low-risk HPV types, and clearance of HPV genetic material before sampling. Imprecise disease threshold definition lead to FN results in visual inspection with acetic acid. Lesions with a discrete colposcopic appearance are a source of FN in colposcopic procedures. For FAM19A4 and hsa-miR124-2 genes methylation, those may originate from borderline methylation levels. Histological misinterpretation, sampling, and laboratory errors also play a role in all types of CC screening, as well as reproducibility issue, especially in methods based on human-eye evaluation. Primary HPV-based screening combined with high quality-assured immunocytochemical and molecular triage methods seem to be an optimal approach. Colposcopy with histological evaluation remains the gold standard for diagnosis but requires quality protocols and assurance measures.

Understanding women's choices for management of cervical intraepithelial neoplasia 2 (CIN2): Qualitative analysis of a randomised experimental study

BACKGROUND

Active surveillance for cervical intraepithelial neoplasia 2 (CIN2) would allow time for most cases to regress naturally and in turn avoid potentially unnecessary and harmful treatment.

AIM

To determine reasons for choosing active surveillance over surgery among women given a hypothetical diagnosis of CIN2.

MATERIALS AND METHODS

Women residing in Australia aged 25-40 years with no prior diagnosis of cervical cancer, cervical abnormality CIN2 or above, and/or previous hysterectomy, were randomised to one of four identical hypothetical scenarios of testing human papillomavirus (HPV)-positive: high-grade cytology and a diagnosis of CIN2 that used alternate terminology to describe resolution of abnormal cells and/or inclusion of an overtreatment statement. Participants selected active surveillance or surgery after viewing the scenario and free-text reason/s for their choice were thematically analysed.

RESULTS

Of the 1638 women randomised, 79% (n = 1293) opted for active surveillance. The most common reasons for choosing active surveillance included concerns about surgery and associated risks, preferring to 'wait and see', trusting the doctor's recommendations and having an emotional response toward surgery. For women who chose surgery, being risk-averse, addressing the issue straight away and perceiving surgery to be the better option for them were the most common themes identified.

CONCLUSION

When presented with balanced information on the benefits and harms of different management options for CIN2 and given a choice, most women in this hypothetical situation chose active surveillance over surgery. Addressing women's concerns about active surveillance may open up the possibility that if deemed safe, it could be an acceptable alternative for women.

The Natural History of Cervical Intraepithelial Neoplasia Grades 1, 2, and 3: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study was to obtain an updated overview of regression, persistence, and progression rates of conservatively managed cervical intraepithelial neoplasia grade 1 (CIN 1)/CIN 2/CIN 3.

METHODS

Data sources were MEDLINE, Embase, and Cochrane (January 1, 1973-April 14, 2020). Two reviewers extracted data and assessed risk of bias. To estimate outcome rates, we pooled proportions of the individual study results using random-effects meta-analysis, resulting in point estimates and corresponding 95% CIs. Heterogeneity was quantified by the I2 and τ2 measures.

RESULTS

Eighty-nine studies were included, 63 studies on CIN 1 (n = 6,080-8,767), 42 on CIN 2 (n = 2,909-3,830), and 7 on CIN 3 (n = 245-351). The overall regression, persistence, and progression to CIN 2 or worse and CIN 3 or worse rates for women with conservatively managed CIN 1 were 60% (95% CI = 55-65, I2 = 92%), 25% (95% CI = 20-30, I2 = 94%), 11% (95% CI = 8-13, I2 = 89%), and 2% (95% CI = 1-3, I2 = 82%), respectively. The overall regression, persistence, and progression rates for CIN 2 were 55% (95% CI = 50-60, I2 = 85%), 23% (95% CI = 19-28, I2 = 83%), and 19% (95% CI = 15-23, I2 = 88%), respectively. Finally, for CIN 3, these were 28% (95% CI = 17-41, I2 = 68%), 67% (95% CI = 36-91, I2 = 84%), and 2% (95% CI = 0-25, I2 = 95%), respectively. Cervical intraepithelial neoplasia grade 2 regression was significantly higher in women 30 years or younger and high-risk human papillomavirus-negative women (66%, 95% CI = 62-70, I2 = 76%; 94%, 95% CI = 84-99, I2 = 60%). Only 2/7,180 (0.03%) and 10/3,037 (0.3%) of the CIN 1 and CIN 2 cases progressed to cervical cancer.

CONCLUSIONS

Most CIN 1/CIN 2 will regress spontaneously in less than 24 months, with the highest rates in high-risk human papillomavirus-negative and young women, whereas progression to cancer is less than 0.5%. Conservative management should be considered, especially in fertile women and with expected high compliance. Given the heterogeneity in regression rates of high-grade histology, this should be classified as CIN 2 or CIN 3 to guide management.

Histopathological correlation of cervical biopsy and tissue after excision in patients with precancerous lesions of the cervix

INTRODUCTION

Cervical intraepithelial neoplasia (CIN) are precancerous lesion of cervix, with incidence of 1.6 per 1000 for CIN 1 lesion and 1.2 per 1000 for CIN 3 lesion in USA. According to IARC incidence is higher in less developed and developing countries. Taking into account the fact that the sensitivity, specificity and accuracy of Papanicolaou swab and colposcopy vary, the final diagnosis is made by colposcopically guided biopsy and by excisions of the cervix.

AIM OF THE STUDY

Comparing the histopathological findings of cervical biopsy and definitive histopathological findings after cervical excision in precancerous lesions of the cervix in relation to the degree of lesion, age and institution, where the biopsy was performed.

MATERIALS AND METHODS

The study was retrospective and was conducted on a group of patients who underwent some excision techniques on the cervix after obtaining a histological finding of the cervical biopsy.

RESULTS

In a total sample of 168 patients, a correlation of histopathological analysis of biopsy material and excision techniques was observed in 62.5% (105/168). This correlation was statistically significant (χ² = 5.333, df 1; p = 0.0209). The greater correlation of histopathological material of biopsies and final histopathological material after excisions were obtained in Oncology Institute of Vojvodina (OIV) without statistical significance.

CONCLUSION

A statistically significant accuracy of biopsy was noted in examined group of patients.

Correlation between Human Papillomavirus Codetection Profiles and Cervical Intraepithelial Neoplasia in Japanese Women

Human papillomavirus (HPV) infection is thought to be strongly associated with the precarcinomatous state cervical intraepithelial neoplasia (CIN) and cervical carcinoma. To accurately assess the correlation between HPV detection profiles and CIN, the uniplex E6/E7 polymerase chain reaction (PCR) method was used. We detected HPV (37 genotypes) in 267 CIN cases. The detection of a single high-risk HPV genotype occurred in 69.7% of CIN1 and worse than CIN1 (CIN1+) cases whereas other types were detected in 11.6% of cases. Codetection of high-risk HPV genotypes occurred in 4.9% of CIN1+ cases. The high-risk genotype HPV16 was the most frequently detected genotype in CIN1+ lesions; the genotype HPV34 (not a high-risk type) was detected in some CIN3 cases. Furthermore, HPV codetection may not be associated with CIN grades. These results suggest that various HPV genotypes are associated with CIN across all analyzed cases.

Current status of development of methylation biomarkers for in vitro diagnostic IVD applications

A significant volume of research clearly shows that disease-related methylation changes can be used as biomarkers at all stages of clinical disease management, including risk assessment and predisposition screening through early diagnostics to personalization of patient care and monitoring of the relapse and chronic disease. Thus disease-related methylation changes are an attractive source of the biomarkers that can have significant impact on precision medicine. However, the translation of the research findings in methylation biomarkers field to clinical practice is at the very least not satisfactory. That is mainly because the evidence generated in research studies indicating the utility of the disease-related methylation change to predict clinical outcome is in majority of the cases not sufficient to postulate the diagnostic use of the biomarker. The research studies need to be followed by well-designed and systematic investigations of clinical utility of the biomarker that produce data of sufficient quality to meet regulatory approval for the test to be used to make clinically valid decision. In this review, we describe methylation-based IVD tests currently approved for IVD use or at the advanced stages of the development for the diagnostic use. For each of those tests, we analyze the technologies that the test utilizes for methylation detection as well as describe the types of the clinical studies that were performed to show clinical validity of the test and warrant regulatory approval. The examples reviewed here should help with planning of clinical investigations and delivery of the clinical evidence required for the regulatory approval of potential methylation biomarker based IVD tests.

The role of EP3-receptor expression in cervical dysplasia

PURPOSE

Prostaglandin-mediated inflammatory reactions play a major role in different cancers. Prostaglandin E2-receptor 3 (EP3) expression correlates with FIGO stages in cervical cancer and has been shown to be an independent prognostic factor for overall survival. EP3 expression levels in cervical intraepithelial neoplasia (CIN) as the precursor lesion of cervical cancer are currently unknown.

METHODS

EP3 expression was analyzed by immunohistochemistry in 124 patient samples (CIN 1-3 and healthy controls) using the IR-scoring system. Expression levels were correlated with clinical outcome to assess for prognostic relevance in patients with CIN 2. Data analysis was performed using Kruskal-Wallis and Mann-Whitney U test.

RESULTS

EP3 expression levels significantly correlated with different grades of cervical dysplasia. Median EP3-IRS in healthy cervical tissue was 12 (n = 13) compared to 9 in CIN 1 (n = 38; p = 0.031 vs. healthy control), 6 in CIN 2 (n = 45; p < 0.001 vs. CIN 1) and 4 in CIN 3 (n = 28, p = 0.008 vs. CIN 2). The percentage of EP3 expressing cells in CIN 2 lesions was significantly lower in progressive than in regressive cases (mean percentage of EP3 positive cells in progress: 3.8%, n = 18; in regress: 9.3%, n = 20; p = 0.040).

CONCLUSION

EP3 expression significantly decreases with higher grades of cervical intraepithelial neoplasia-which is in line with published IR scores in cervical cancer patients-and seems to be a prognostic marker for regression or progression of CIN 2 lesions. Our findings support the importance of the prostanoid pathway in cervical cancer and could help to identify targets for future therapies.

Expression of Sialyl Lewis a, Sialyl Lewis x, Lewis y, Gal-3, Gal-7, STMN1 and p16 in cervical dysplasia

AIM

Cervical intraepithelial neoplasia (CIN) is commonly divided into three grades. Guidelines increasingly recommend surgery only in CIN 3 lesions. We investigated markers to evaluate differences in CIN 2 and 3 lesions as well as possible predictors for regression/progression in CIN 2 lesions.

MATERIALS & METHODS

Biopsies (n = 128) of healthy cervical tissue and CIN 1-3 were stained for Sialyl Lewis a, Sialyl Lewis x, Lewis y, Gal-3, Gal-7, STMN1 and p16.

RESULTS

We observed significant differences between CIN 2 and 3 lesions for Sialyl Lewis a, Sialyl Lewis x, Gal-3, Gal-7, STMN1 and p16. Expression of Sialyl Lewis a was significantly higher in CIN 2 patients who progressed during follow-up.

CONCLUSION

Significant differences in marker expression support the differentiation of CIN 2 and 3. Lewis a may help to predict progression/regression in CIN 2 patients.

From Human Papillomavirus (HPV) Detection to Cervical Cancer Prevention in Clinical Practice

The newly gained knowledge of the viral etiology in cervical carcinogenesis has prompted industrial interests in developing virology-based tools for cervical cancer prevention. Due to the long incubation period from viral infection to developing an invasive cancer, a process whose outcome is influenced by numerous life-style and genetic factors, the true efficacy of the genotype-specific human papillomavirus (HPV) vaccines in cervical cancer prevention cannot be determined for another 30 years. Most HPV DNA test kits designed to replace the traditional Papanicolaou (Pap) smears for precancer detection lack the analytical sensitivity and specificity to comprehensively detect all potentially carcinogenic HPVs and to perform reliable genotyping. The authors implemented the classic nested PCR and Sanger DNA-sequencing technology for routine HPV testing. The results showed a true negative HPV PCR invariably indicates the absence of precancerous cells in the cytology samples. However, 80.5% of single positive HPV-16 tests and 97.3% of single positive HPV-18 tests were associated with a negative or a largely self-reversible Pap cytology. Routine sensitive and reliable HPV type-specific or perhaps even variant-specific methods are needed to address the issues of persistence of HPV infection if a virology-based primary cervical screen is used to replace the Pap cytology screening paradigm.

Prevalence and viral load of 51 genital human papillomavirus types and three subtypes

Of the 120 known human papillomaviruses (HPV), 51 HPV types infect the genital mucosa. Very little is known about the prevalence and viral load of the majority of these low-risk (Lr-) HPV types in screening populations. We determined the prevalence of 51 HPV types and three subtypes in 999 consecutive BD-SurePath™ liquid-based cervical cytology samples collected during routine gynecological health checks from Belgian women. This series of screening samples was enriched with ASC-US (n = 100), low-grade squamous intraepithelial lesion LSIL (n = 100) and high-grade squamous intraepithelial lesion (HSIL) (n = 97) and analyzed by BSGP5+/6+-PCR/MPG assay for 51 HPV types and three subtypes. In consecutive screening samples, any of the 54 genital HPV (sub)types was found in 37.1%; Hr-HPV types were detected more frequently (26.8%) than the 31 Lr-HPV types (16.4%) and the six possibly high-risk types (6.6%). High viral load infections were present in 17.0% of the screening population. Among the women with cytological abnormalities, the prevalence of high viral loads of Hr-HPV types increased from negative for intraepithelial lesion or malignancy (NIL/M) over ASC-US, LSIL to HSIL (5.3, 47.1, 84.2 and 91.8%, respectively). The prevalence of possibly Hr and Lr-HPV types increased from NIL/M to LSIL but declined to HSIL. From NIL/M to HSIL, Hr-HPV infections showed an increasing frequency of high viral loads compared to total DNA positivity, but the increase between LSIL and HSIL was small. Type-specific analyses revealed substantial differences between individual HPV types in these groups. Our study provides quantitative data for the whole spectrum of genital HPV in a Belgian screening population and in a representative set of women with cervical abnormalities.

Risk estimates for persistent high-risk human papillomavirus infections as surrogate endpoints of progressive cervical disease critically depend on reference category: analysis of the combined prospective cohort of the New Independent States of the Former Soviet Union and Latin American Screening Studies

Summary

To make feasible future clinical trials with new-generation human papillomavirus (HPV) vaccines, novel virological surrogate endpoints of progressive disease have been proposed, including high-risk HPV (HR-HPV) persistence for six months (6M+) or 12 months (12M+). The risk estimates (relative risks [RRs]) of these ‘virological endpoints’ are influenced by several variables, not yet validated adequately. We compared the impact of three referent groups: (i) HPV-negative, (ii) HPV-transient, (iii) HPV-mixed outcome on the risk estimates for 6M+ or 12M+ HR-HPV persistence as predictors of progressive disease. Generalized estimating equation models were used to estimate the strength of 6M+ and 12M+ HR-HPV persistence with disease progression to squamous intraepithelial lesions (SILs), cervical intraepithelial neoplasia (CIN) grade 1 +, CIN2+, CIN/SIL endpoints, comparing three optional reference categories (i)-(iii) in a prospective sub-cohort of 1865 women from the combined New Independent States of the Former Soviet Union (NIS) and Latin American Screening (LAMS) studies cohort ( n = 15,301). The RRs of these viral endpoints as predictors of progressive disease are affected by the length of viral persistence (6M+ or 12M+) and the surrogate endpoint (SIL, CIN1, CIN2, CIN/SIL). Most dramatic is the effect of the referent group used in risk estimates, with the HPV-negative referent group giving the highest and most consistent RRs for both 6M+ and 12M+ viral persistence, irrespective of which surrogate is used. In addition to deciding on whether to use 6M+ or 12M+ persistence criteria, and cytological, histological or combined surrogate endpoints, one should adopt the HPV-negative referent group as the gold standard in all future studies using viral persistence as the surrogate endpoint of progressive disease.

Signature sequence validation of human papillomavirus type 16 (HPV-16) in clinical specimens

Aims

Persistent infection indicated by detection of human papillomavirus 16 (HPV-16) on repeat testing over a period of time poses the greatest cervical cancer risk. However, variants of HPV-16, HPV-31 and HPV-33 may share several short sequence homologies in the hypervariable L1 gene commonly targeted for HPV genotyping. The purpose of this study was to introduce a robust laboratory procedure to validate HPV-16 detected in clinical specimens, using the GenBank sequence database as the standard reference for genotyping.

Methods

A nested PCR with two pairs of consensus primers was used to amplify the HPV DNA released in crude proteinase K digest of the cervicovaginal cells in liquid-based Papanicolaou cytology specimens. The positive nested PCR products were used for direct automated DNA sequencing.

Results

A 48-base sequence downstream of the GP5+ priming site, or a 34-base sequence upstream thereof, was needed for unequivocal validation of an HPV-16 isolate. Selection of a 45-base, or shorter, sequence immediately downstream of the GP5+ site for Basic Local Alignment Search Tool sequence analysis invariably led to ambiguous genotyping results.

Conclusions

DNA sequence analysis may be used for differential genotyping of HPV-16, HPV-31 and HPV-33 in clinical specimens. However, selection of the signature sequence for Basic Local Alignment Search Tool algorithms is crucial to distinguish certain HPV-16 variants from other closely related HPV genotypes.

[HPV immunization for the prevention of cervical cancer]

CONTEXT

Human Papillomaviruses (HPV) infect epithelial cells of the skin and mucosae. Mucosal high-risk HPV types (mainly HPV 16 and 18) are involved in the development of cervical cancer, one of the most common cancers in young women. HPV infection is usually asymptomatic and clears spontaneously, but 10 - 15 % of high-risk HPV infections are persistent and increase the risk of precancerous and cancerous lesions of the cervix. Two HPV vaccines have been licensed to provide protection against cervical cancer.

OBJECTIVES

To report the different aspects of HPV infection in order to improve the understanding of the particular problems of HPV vaccination and to review the most recent findings related to HPV vaccines, particularly regarding the protective efficacy of vaccines and the roles of adjuvants and immune response in protection.

METHODS

Articles were selected from the PubMed database (National Library of Medicine- National Institute of Health) with the following Keywords "HPV", "Prevention", "HPV vaccines", "Immune response", "Antibody". Abstracts of oral presentations from international meetings were also selected for the more recent findings. a critical analysis of the majority of papers published was undertaken and relevant information summarized.

RESULTS

Virus-like particle production by expressing the major protein of the HPV capsid was carried out in the early 90's, leading to the recent development of two HPV vaccines. These vaccines are now licensed in many countries and have been demonstrated to be highly immunogenic. In subjects that are non-infected at the time of vaccination, HPV vaccines are highly effective in preventing persistent HPV 16 - 18 infections (90 %) and precursors lesions of cervical cancer associated with these two HPV types (close to 100 %). Clinical trials have also confirmed that HPV vaccines are well tolerated by recipients.

CONCLUSIONS

The present paper is a detailed review published in French on HPV vaccines, their efficacy in the prevention of HPV infections and unresolved questions regarding the use of HPV vaccines. This report also includes biological and immunological information to improve the understanding of HPV vaccination.

Persistent high-risk human papillomavirus infections and other end-point markers of progressive cervical disease among women prospectively followed up in the New Independent States of the Former Soviet Union and the Latin American Screening study cohorts

BACKGROUND

New end points are needed in future human papillomavirus (HPV) vaccine efficacy studies that accurately predict disease progression.

OBJECTIVES

Potential intermediate end points were analyzed in the combined New Independent States of the Former Soviet Union (NIS) and the Latin American Screening (LAMS) study cohorts.

STUDY DESIGN AND METHODS

Data files of 2 international screening trials, the NIS (n = 3187) and the LAMS (n = 12,114) study cohorts, were combined, and a subcohort of 1865 (n = 854 and n = 1011 for the NIS and the LAMS, respectively) women prospectively followed up for 19.7 (median, 22.2) months was analyzed for different intermediate end-point markers of disease progression to squamous intraepithelial lesion (SIL), cervical intraepithelial neoplasia grade 1 and higher (CIN1+), and CIN grade 2 and higher (CIN2+) as terminal events.

RESULTS

: Altogether, 131 (7.0%), 90 (4.8%), and 39 (2.1%) cases progressed to SIL, CIN1+, and CIN2+, respectively, progression times being equal in the NIS (11.9, 16.8, and 19.6 months) and LAMS (13.6, 14.1, and 15.4 months) cohorts (P = 0.931, P = 0.335, and P = 0.535). The 2 most powerful end-point markers of disease progression to CIN2+ were high-grade squamous intraepithelial lesions based on Papanicolaou test results at 6-month (odds ratio [OR] = 47.1; 95% confidence interval [CI], 17.3-128.7) and 12-month (OR = 21.5; 95% CI, 5.1-90.8) follow-up visits, with longitudinal positive and negative predictive values of 42.1% and 98.0% (6 months) and 33.3% and 97.7% (12 months). Of the virological end points, more than 6 months of persistent high-risk HPV (HR-HPV) was the most powerful predictor of progression to CIN1+ (OR = 18.6; 95% CI, 2.5-136.5), with longitudinal positive and negative predictive values of 10.3% and 99.4%, respectively. No additional benefit was obtained using more than 12 months of persistent HR-HPV end point.

CONCLUSIONS

High-grade squamous intraepithelial lesion based on a Papanicolaou test results at 6- or 12-month follow-up visits was the most powerful end point, either considering cytological end points alone or in comparison to any of the virological end points. Of the virological end points, more than 6-month HR-HPV persistence criteria give the most powerful estimate of a progressive disease.

Validation of human papillomavirus genotyping by signature DNA sequence analysis

BACKGROUND

Screening with combined cytologic and HPV testing has led to the highest number of excessive colposcopic referrals due to high false positive rates of the current HPV testing in the USA. How best to capitalize on the enhanced sensitivity of HPV DNA testing while minimizing false-positive results from its lower specificity is an important task for the clinical pathologists.

METHODS

The HPV L1 gene DNA in liquid-based Pap cytology specimens was initially amplified by the degenerate MY09/MY11 PCR primers and then re-amplified by the nested GP5+/GP6+ primers, or the heminested GP6/MY11, heminested GP5/MY09 primers or their modified equivalent without sample purification or DNA extraction. The nested PCR products were used for direct automated DNA sequencing. A 34- to 50-base sequence including the GP5+ priming site was selected as the signature sequence for routine genotyping by online BLAST sequence alignment algorithms.

RESULTS

Of 3,222 specimens, 352 were found to contain HPV DNA, with 92% of the positive samples infected by only 1 of the 35 HPV genotypes detected and 8% by more than 1 HPV genotype. The most common genotype was HPV-16 (68 isolates), followed by HPV-52 (25 isolates). More than half (53.7%) of the total number of HPV isolates relied on a nested PCR for detection although the majority of HPV-16, -18, -31, -33 -35 and -58 isolates were detected by a single MY09/MY11 PCR. Alignment of a 34-base sequence downstream of the GP5+ site failed to distinguish some isolates of HPV-16, -31 and -33. Novel variants of HPV with less than "100% identities" signature sequence match with those stored in the Genbank database were also detected by signature DNA sequencing in this rural and suburban population of the United States.

CONCLUSION

Laboratory staff must be familiar with the limitations of the consensus PCR primers, the locations of the signature sequence in the L1 gene for some HPV genotypes, and HPV genotype sequence variants in order to perform accurate HPV genotyping.

Molecular tests for human papillomavirus (HPV), Chlamydia trachomatis and Neisseria gonorrhoeae in liquid-based cytology specimen

BACKGROUND

Laboratory detection of Human papillomavirus (HPV), Chlamydia trachomatis and Neisseria gonorrhoeae in liquid-based cervicovaginal cytology specimens is now based on identification of the DNA sequences unique to these infectious agents. However, current commercial test kits rely on nucleotide probe hybridization to determine DNA sequences, which may lead to diagnostic errors due to cross-reactivity. The aim of this study was to find a practical approach to perform automated Sanger DNA sequencing in clinical laboratories for validation of the DNA tests for these three infectious agents.

METHODS

A crude proteinase K digest of 5% of the cells collected in a liquid-based cervicovaginal cytology specimen was used for the detection of DNA molecules specific for HPV, C trachomatis and N gonorrhoeae, and for preparation of materials suitable for direct automated DNA sequencing. Several sets of commercially available polymerase chain reaction (PCR) primers were used to prepare nested PCR amplicons for direct DNA sequencing.

RESULTS

Some variants of HPV-16 and HPV-31 were found to share an at least 34-base long sequence homology downstream of the GP5+ binding site, and all HPV-6 and HPV-11 variants shared an upstream 34-base sequence including part of the GP5+ primer. Accurate HPV genotyping frequently required more than 34-bases for sequence alignments to distinguish some of the HPV genotype variants with closely related sequences in this L1 gene hypervariable region. Using the automated Sanger DNA sequencing method for parallel comparative studies on split samples and to retest the residues of samples previously tested positive for C trachomatis and/or for N gonorrhoeae, we also found false-negative and false-positive results as reported by two commercial nucleic acid test kits.

CONCLUSION

Identification of a signature DNA sequence by the automated Sanger method is useful for validation of HPV genotyping and for molecular testing of C trachomatis and N gonorrhoeae in liquid-based cervicovaginal Papanicolaou (Pap) cytology specimens for clinical laboratories with experience in molecular biology to increase the specificity of these DNA-based tests. However, even a highly specific test for high-risk HPV genotyping may have unacceptably low positive predictive values for precancer lesion in populations with a low cervical cancer prevalence rate.

Analysis of the dose-response relationship between high-risk human papillomavirus viral load and cervical lesions

The aims of this study were to explore the dose-response relationship between high-risk human papillomavirus (hrHPV) load and cervical lesions; the relationship between hrHPV viral load and the severity of cervical lesions; and the clinical application of the hybrid capture II (HC-II) system in the secondary prevention of cervical cancer. HrHPV viral load was detected by the HC-II system and cervical lesions were diagnosed from biopsied tissue. Curve estimation and Mantel trend analysis were used to explore the dose-response relationship between hrHPV viral load and cervical lesions. Spearman's rank correlation analysis and ordinal regression model were used for the analysis of hrHPV viral load and the severity of cervical lesions. Curve estimation showed good correlation between cervical lesion rates and hrHPV viral load (r=0.775, P=0.008); the rate of cervical lesions increased with hrHPV viral load (chi(trend)=8.000, P<0.001). Medium intensity rank correlation was found between hrHPV viral load grades and the severity of cervical lesions (r(s)=0.321, P<0.001); a correlation appeared between hrHPV viral load and the severity of cervical lesions (P<0.001). These results suggest a dose-response relationship between hrHPV viral load and the severity of cervical lesions. This dependence has important clinical applications and shows the potential value of the HC-II system in cervical cancer prevention.

Critical evaluation of HPV16 gene copy number quantification by SYBR green PCR

BACKGROUND

Human papilloma virus (HPV) load and physical status are considered useful parameters for clinical evaluation of cervical squamous cell neoplasia. However, the errors implicit in HPV gene quantification by PCR are not well documented. We have undertaken the first rigorous evaluation of the errors that can be expected when using SYBR green qPCR for quantification of HPV type 16 gene copy numbers. We assessed a modified method, in which external calibration curves were generated from a single construct containing HPV16 E2, HPV16 E6 and the host gene hydroxymethylbilane synthase in a 1:1:1 ratio.

RESULTS

When testing dilutions of mixed HPV/host DNA in replicate runs, we observed errors in quantifying E2 and E6 amplicons of 5-40%, with greatest error at the lowest DNA template concentration (3 ng/microl). Errors in determining viral copy numbers per diploid genome were 13-53%. Nevertheless, in cervical keratinocyte cell lines we observed reasonable agreement between viral loads determined by qPCR and Southern blotting. The mean E2/E6 ratio in episome-only cells was 1.04, but with a range of 0.76-1.32. In three integrant-only lines the mean E2/E6 ratios were 0.20, 0.72 and 2.61 (values confirmed by gene-specific Southern blotting). When E2/E6 ratios in fourteen HPV16-positive cervical carcinomas were analysed, conclusions regarding viral physical state could only be made in three cases, where the E2/E6 ratio was < or = 0.06.

CONCLUSION

Run-to-run variation in SYBR green qPCR produces unavoidable inaccuracies that should be allowed for when quantifying HPV gene copy number. While E6 copy numbers can be considered to provide a useable indication of viral loads, the E2/E6 ratio is of limited value. Previous studies may have overestimated the frequency of mixed episomal/integrant HPV infections.

Evaluation of different techniques for identification of human papillomavirus types of low prevalence

Human papillomaviruses (HPVs) have been recognized as etiologic factors in a variety of diseases. Due to the large number of HPV types, methods for HPV genotyping are difficult to standardize. Despite this fact, several methods exist, and some of them are available commercially. In this study, we evaluated the Roche Diagnostics linear array (LA) HPV genotyping assay, the Innogenetics INNO-LiPA (line probe assay [LiPA]), and two noncommercial reverse line blot (RLB) assays based on either primers GP5+ and GP6+ (GP) or newly designed broad-spectrum primers BSGP5+ and BSGP6+ (BS). The reliabilities of these assays were tested with a wide spectrum of HPV types less prevalent in cervical samples. This is the first study to compare the performance of the most widely used HPV genotyping methods with selected samples positive for low-prevalence HPV types. We focused on interassay agreement, both overall and type specific, in cases with single and/or multiple HPV infections. Interassay agreement was moderate in cases of single HPV infections and poor in cases of multiple HPV infections. The LA and the BS-based RLB assays found a higher rate of cases positive for multiple HPV types than LiPA and the GP-based RLB assay. The weakest capability in detecting multiple HPV infections was observed for LiPA. The use of only one assay in epidemiological and clinical studies might lead to biased conclusions. Therefore, a universally evaluated and agreed upon HPV typing assay or a combination of current assays is needed for possible clinical applications, and knowledge of their limitations is advised.

Perceived stress is associated with impaired T-cell response to HPV16 in women with cervical dysplasia

BACKGROUND

Infection with high-risk subtypes of human papillomavirus (HPV) is a central factor in the development of cervical neoplasia. Cell-mediated immunity against HPV16 plays an important role in the resolution of HPV infection and in controlling cervical disease progression. Research suggests that stress is associated with cervical disease progression, but few studies have examined the biological mechanisms that may be driving this association.

PURPOSE

This study examines whether stress is associated with immune response to HPV16 among women with cervical dysplasia.

METHODS

Seventy-four women presenting for colposcopy completed measures of health behaviors, stressful life events and perceived stress. A blood sample was obtained to evaluate proliferative T-cell response to HPV16, and a cervical sample was obtained during gynecologic exam for HPV-typing.

RESULTS

More than 55% tested positive for one or more HPV subtypes. Women who did not show proliferative responses to HPV (i.e. non-responders) were more likely to be HPV(+) compared to women who had a response (i.e. responders). Consistent with study hypotheses, logistic regression revealed that higher levels of perceived stress were associated with a non-response to HPV16, controlling for relevant covariates. Stressful life events were not associated with T-cell response to HPV.

CONCLUSIONS

Higher levels of perceived stress are associated with impaired HPV-specific immune response in women with cervical dysplasia, suggesting a potential mechanism by which stress may influence cervical disease progression.

Augmented serum level of major histocompatibility complex class I-related chain A (MICA) protein and reduced NKG2D expression on NK and T cells in patients with cervical cancer and precursor lesions

BACKGROUND

Cervical cancer is the second most common cancer in women worldwide. NK and cytotoxic T cells play an important role in the elimination of virus-infected and tumor cells through NKG2D activating receptors, which can promote the lysis of target cells by binding to the major histocompatibility complex class I-related chain A (MICA) proteins. Increased serum levels of MICA have been found in patients with epithelial tumors. The aim of this study was to compare the levels of soluble MICA (sMICA) and NKG2D-expressing NK and T cells in blood samples from patients with cervical cancer or precursor lesions with those from healthy donors.

METHODS

Peripheral blood with or without heparin was collected to obtain mononuclear cells or sera, respectively. Serum sMICA levels were measured by ELISA and NKG2D-expressing immune cells were analyzed by flow cytometry. Also, a correlation analysis was performed to associate sMICA levels with either NKG2D expression or with the stage of the lesion.

RESULTS

Significant amounts of sMICA were detected in sera from nearly all patients. We found a decrease in the number of NKG2D-expressing NK and T cells in both cervical cancer and lesion groups when compared to healthy donors. Pearson analysis showed a negative correlation between sMICA and NKG2D-expressing T cells; however, we did not find a significant correlation when the analysis was applied to sMICA and NKG2D expression on NK cells.

CONCLUSION

Our results show for the first time that high sMICA levels are found in sera from patients with both cervical cancer and precursor lesions when compared with healthy donors. We also observed a diminution in the number of NKG2D-expressing NK and T cells in the patient samples; however, a significant negative correlation between sMICA and NKG2D expression was only seen in T cells.

Inter-laboratory validation of PCR-based HPV detection in pathology specimens

The detection and typing of human papilloma virus (HPV) in pathology specimens is gaining increasingly in importance. In the context of the initiative for quality assurance in pathology (QuIP) of the German Society of Pathology and the Professional Association of German Pathologists, four panel laboratories with experience and expertise in polymerase chain reaction (PCR)-based HPV detection were selected to establish an inter-laboratory trial. In a first step, these laboratories performed an internal testing of their own methodologies, which comprised DNA sequencing, multiplex nested PCR and hybridization techniques. Material from 39 samples including paraffin sections and DNA preparations of tissues and plasmids were evaluated by each panel institute according to their own protocols. Despite the different methodologies, a high degree of inter-laboratory reliability was achieved. In this report, we summarise the results. Pretested specimens are available for the external trail and can be ordered from the steering institute via provitro GmbH Berlin ( http://www.provitro.de ). Supplementary data are online available at http://pathologie-ccm.charite.de (rubric "Forschung"), which includes a web-based photo gallery of HPV-associated lesions and their potential association with specific virus types. The initiative is intended to foster the quality assurance of molecular HPV analysis in pathology and its correlation with morphological changes.

Routine human papillomavirus genotyping by DNA sequencing in community hospital laboratories

Background

Human papillomavirus (HPV) genotyping is important for following up patients with persistent HPV infection and for evaluation of prevention strategy for the individual patients to be immunized with type-specific HPV vaccines. The aim of this study was to optimize a robust "low-temperature" (LoTemp™) PCR system to streamline the research protocols for HPV DNA nested PCR-amplification followed by genotyping with direct DNA sequencing. The protocol optimization facilitates transferring this molecular technology into clinical laboratory practice. In particular, lowering the temperature by 10°C at each step of thermocycling during in vitro DNA amplification yields more homogeneous PCR products. With this protocol, template purification before enzymatic cycle primer extensions is no longer necessary.

Results

The HPV genomic DNA extracted from liquid-based alcohol-preserved cervicovaginal cells was first amplified by the consensus MY09/MY11 primer pair followed by nested PCR with GP5+/GP6+ primers. The 150 bp nested PCR products were subjected to direct DNA sequencing. The hypervariable 34–50 bp DNA sequence downstream of the GP5+ primer site was compared to the known HPV DNA sequences stored in the GenBank using on-line BLAST for genotyping. The LoTemp™ ready-to-use PCR polymerase reagents proved to be stable at room temperature for at least 6 weeks. Nested PCR detected 107 isolates of HPV in 513 cervicovaginal clinical samples, all validated by DNA sequencing. HPV-16 was the most prevalent genotype constituting 29 of 107 positive cases (27.2%), followed by HPV-56 (8.5%). For comparison, Digene HC2 test detected 62.6% of the 107 HPV isolates and returned 11 (37.9%) of the 29 HPV-16 positive cases as "positive for high-risk HPV".

Conclusion

The LoTemp™ ready-to-use PCR polymerase system which allows thermocycling at 85°C for denaturing, 40°C for annealing and 65°C for primer extension can be adapted for target HPV DNA amplification by nested PCR and for preparation of clinical materials for genotyping by direct DNA sequencing. HPV genotyping is performed by on-line BLAST algorithm of a hypervariable L1 region. The DNA sequence is included in each report to the physician for comparison in following up patients with persistent HPV infection, a recognized tumor promoter in cancer induction.

[What does HPV vaccination mean for gynecologic cancer screening?]

Human papilloma viruses (HPV) of the high-risk type cause almost all cervical carcinomas and some other anogenital tumors. Development of a carcinoma is uncommon; most infections heal spontaneously. When carcinomas develop, the latent phase is at least 8, more often 15-30 years. A negative HPV test thus excludes the risk of developing cervical carcinoma for many years. The approved vaccine against HPV 6/11/16/18 and the soon-to-be-approved one against HPV 16/18 are extremely safe and effective. Vaccinated individuals are almost 100% protected by the vaccines containing virus-like particles. Current studies suggest that 70-80% of high-grade cervical neoplasias can be avoided, as well as other vaginal, vulvar, and anal neoplasias. The yearly costs for treating precursors of these cancers exceed the cost of vaccinating all girls born in a given year. Thus HPV vaccination is cost effective, even when a modified cancer screening program is retained.

Distribution and viral load of eight oncogenic types of human papillomavirus (HPV) and HPV 16 integration status in cervical intraepithelial neoplasia and carcinoma

Current human papillomavirus (HPV) DNA testing using pooled probes, although sensitive, lacks specificity in predicting the risk of high-grade cervical intraepithelial neoplasia (CIN 2/3) progression. To evaluate selected HPV genotyping, viral load, and viral integration status as potential predictive markers for CIN progression, we performed HPV genotyping in formalin-fixed, paraffin-embedded cervical tissue with cervical carcinoma (29 cases) and CINs (CIN 1, 27 cases; CIN 2, 28 cases; CIN 3, 33 cases). General HPVs were screened using consensus primers GP5+/GP6+ and PGMY09/11. HPV genotyping and viral load measurement were performed using quantitative real-time PCR for eight oncogenic HPV types (16, 18, 31, 33, 35, 45, 52, and 58). HPV 16 viral integration status was evaluated by measuring HPV 16 E2/E6 ratio. We observed that HPV DNA positivity increased in parallel with the severity of CINs and carcinoma, with 59% positivity in CIN 1, 68% in CIN 2, 76% in CIN 3, and 97% in carcinoma (P trend=0.004). The eight oncogenic HPV types were significantly associated with CIN 2/3 (81%) and carcinoma (93%) (odds ratio (OR), 15.0; 95% confidence interval (CI), 5.67-39.76; P<0.0001) compared with the unknown HPV types (OR, 2.87; 95% CI, 0.89-9.22; P=0.08). HPV 16 was the predominant oncogenic HPV type in CIN 2/3 (51%) and carcinoma (71%) and integrated significantly more frequently in carcinoma than in CIN 2/3 (P=0.004). No significant differences in viral load were observed across the disease categories. Our findings suggest that selected genotyping for the eight oncogenic HPV types might be useful in separating women with a higher risk of CIN progression from those with a minimal risk. We also conclude that the HPV 16 integration status has potential to be a marker for risk assessment of CIN progression.

Recovery of human papillomavirus nucleic acids from liquid-based cytology media

Residual material from liquid-based cytology (LBC) samples, collected during cervical screening, is a valuable resource for molecular biological analysis. Because of the central role played by human papillomavirus (HPV) in the development of cervical cancer, assays are being developed to quantify HPV gene expression in LBC material. Using quantitative realtime PCR we have compared recovery of HPV DNA and RNA from two of the most widely used LBC systems (the ThinPrep system (Cytyc Corp.) and the SurePath system (TriPath Imaging, Inc.)). Recovery of RNA was unaffected by storage in ThinPrep media, however storage of cells in SurePath resulted in significantly reduced yields (between 10(4)- and 10(8)-fold reduction depending on extraction technique). Given the increasing prominence and importance of molecular diagnostics and prognostics this is an important finding, and must be considered in relation to choice of LBC system.