NucliSENS EasyQ HPV v1 test - Testing for oncogenic activity of human papillomaviruses

DNA high-risk HPV, mRNA HPV and P16 tests for diagnosis of anal cancer and precursor lesions: a systematic review and meta-analysis

Background

Anal cancer prevention has two critical points: the incidence rate is several fold higher for some groups, such as people living with human immunodeficiency virus (HIV) and men who have sex with men (MSM), and there is not a well-defined guideline for its screening. This systematic review evaluates the accuracy of DNA HRHPV (high-risk human papillomavirus), mRNA HPV, DNA HPV16 isolated and p16 staining biomarkers in anal canal smears for identifying anal intraepithelial neoplasia (AIN) 2 or 3, summarised as anal high-grade squamous intraepithelial lesions (aHSIL), and cancer.

Methods

We searched the MEDLINE, Cochrane Library and Embase electronic databases as well as Grey literature to identify eligible papers published up to 31st July 2022. This systematic review and meta-analysis included observational studies comparing biomarker tests to histopathology after HRA (High-resolution Anoscopy) as a reference standard. We (ACM, TF) analysed studies in which patients of both sexes were screened for anal cancer using DNA HRHPV, mRNA HPV, DNA HPV16 and/or p16 biomarkers. The analysis was performed in pairs, for instance AIN2 or worse (AIN2+) vs. AIN1, HPV infection and normal (AIN1-). PROSPERO CRD42015024201.

Findings

We included 21 studies with 7445 patients. DNA HR HPV showed a higher sensitivity 92.4% (95% CI 84.2-96.5), specificity 41.7% (95% CI 33.9-44.9) and AUC 0.67, followed by the mRNA HPV test, with a sensitivity 77.3% (95% CI 73.2%-80.9%), specificity 61.9% (95% CI 56.6-66.9) and AUC 0.78. DNA HPV16 showed higher specificity 71.7% (95% CI 55.3-83.8), followed by p16 test, 64.1% (95% CI 51.0-75.4); Sensitivity of DNA HPV16 was 53.3% (95% CI 35.4-70.3) and AUC 0.69, while p16 had a sensitivity of 68.8% (95% CI 47.9-84.1) and AUC 0.74. Subgroup analysis of MSM with HIV, with 13 studies and 5123 patients, showed similar accuracy, with a bit higher sensitivities and lower specificities. Considering the measure of the total between-study variability, mRNA HPV tests showed the smallest area of the 95% prediction ellipse, 6.0%, influenced by the low logit sensitivity, 0.011. All other groups of tests exceed 50% prediction ellipse area, which represent a high heterogeneity.

Interpretation

Our findings suggested that DNA HR HPV can be a useful tool for screening for aHSIL and anal cancer if followed by biomarker with a higher specificity. As an isolated test, mRNA HPV had better performance.

Funding

There was no funding source for this study.

Human Papillomavirus-Associated Cancers

Human Papillomavirus (HPV) is the causative agent in the majority of anal, head and neck, oral, oropharyngeal, penile, vaginal, vulvar, and cervical cancers. Cervical cancer is the fourth most common cancer among women worldwide. Of all diagnosed human malignant neoplasms, approximately 4.5% are attributable to HPV, including cervical, anal cancers, vaginal, vulvar, penile, and oropharyngeal cancers. Over 182 HPV types have been identified and sequenced to date however, only certain types of HPV are more frequent in malignant lesions and considered to be a major risk factor in the development of some cancers. Because most HPV infections are transient, and an individual's immunocompetent may clear the infection, HPV infection has received little attention from clinicians, the general public, or policy makers. This lack of attention may underpin a deadly and increasing problem because each newly acquired infection has the potential to persist and become an incurable, lifelong affliction. In addition, no successful treatment of HPV infection currently exists despite the great strides toward understanding the mechanisms underlying HPV pathogenesis. Moreover, ample research has proven that the use of prophylactic vaccines, such as Gardasil and Cervarix, have led to documented progress in decreasing the burden of HPV infection, however not all countries introduced a government-funded National HPV Vaccination Program to protect young men and women. This chapter summarizes the HPV infection, detection and prevention. We also shed light on non-cervical HPV-related cancers, which is rapidly increasing in more developed countries toward cervical cancer.

Advances in technologies for cervical cancer detection in low-resource settings

Introduction: Cervical cancer mortality rates remain high in low- and middle-income countries (LMICs) and other medically underserved areas due to challenges with implementation and sustainability of routine screening, accurate diagnosis, and early treatment of preinvasive lesions. Areas covered: In this review, we first discuss the standard of care for cervical cancer screening and diagnosis in high- and low-resource settings, biomarkers that correlate to cervical precancer and cancer, and needs for new tests. We review technologies for screening and diagnosis with a focus on tests that are already in use in LMICs or have the potential to be adapted for use in LMICs. Finally, we provide perspectives on the next five years of technology development for improved cervical cancer screening and diagnosis in LMICs. Expert opinion: Innovation toward improved molecular and imaging tests is needed to enable effective, affordable see-and-treat approaches to detect and treat cervical precancer in a single visit. Current molecular tests remain too complex and/or costly for widespread use. Especially with imaging tests, decision support may improve performance of new technologies.

Accuracy of mRNA HPV Tests for Triage of Precursor Lesions and Cervical Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review evaluates the accuracy of the mRNA HPV biomarker in cervical smears to identify cervical intraepithelial neoplasia (CIN) 2 or 3 and cervical cancer.

DATA SOURCE

Eligible studies were identified by performing a search of electronic databases on Medline via Pubmed, Lilacs, Cochrane Library, Embase, and Grey literature for papers published between January 1990 and June 2018.

STUDY ELIGIBILITY CRITERIA

As no randomized studies were identified, this review focuses on observational studies in which the mRNA HPV diagnostic test was compared to a histopathology reference standard. We analyzed studies that included women screened for cervical cancer using mRNA HPV.

STUDY APPRAISAL AND SYNTHESIS METHODS

After screening, 61 studies including 29,674 patients met the inclusion criteria and were analyzed. Dichotomization was performed by defining CIN2 or worse (CIN2+) versus CIN1, HPV infection, and normal (CIN 1-). The analysis was discriminated by the following tests: Aptima, PreTect HPV Profeer, NucliSens EasyQ HPV, OncoTect, and Quantivirus.

RESULTS

Analyzing by technique, Aptima, with 28 studies, exhibited superior performance, showing for the outcomes CIN2+ and CIN3+ an AUC of 0.88 (0.82-0.95) and 0.91 (0.84-0.99), a pooled sensitivity of 92.8% (95%CI 91.9-93.7) and 95.6% (95%CI 94.5-96.5), and a pooled specificity of 60.5% (95%CI 59.8-61.3) and 61.9% (95%CI 61.1-62.7), respectively.

CONCLUSION

This study supports the current hypothesis that the mRNA HPV assay is an adequate tool for secondary cervical cancer screening.

Isothermal Amplification Methods for the SNP Genotyping

The demands for genotyping techniques with acceptable precision, accuracy, cost-effectiveness in high throughput formats made driving forces for continuous development of novel technologies. A wide range of mutation detection techniques based on polymerase chain reaction (PCR) have been introduced. The best alternatives were the isothermal amplification technologies that those did not require a thermal cycler. In this review, we aimed to describe the most known isothermal amplification techniques for SNP genotyping.

Accuracy of mRNA HPV tests as a predictor of recurrence of precursor lesions and cervical cancer after conization: a systematic review and meta-analysis

Objective: This systematic review evaluates the accuracy of mRNA HPV biomarker for the identification of cervical intra-epithelial neoplasia (CIN) or cervical cancer during a follow-up after conization, taking histopathology as reference standard. Methods: A search of electronic databases was performed, for studies published until June 2018. As results, after screening, five studies including 1148 patients met the inclusion criteria. Dichotomization was performed by CIN2+ versus CIN1-. By analyzing all five studies, a sensitivity of 62.4% (95% CI: 54.8-69.7), specificity of 91.9% (95% CI: 90.0-93.5) and area under the curve of 0.5685 were revealed. Conclusion: mRNA HPV assay presents a high specificity and is an adequate tool for cervical cancer screening in the follow-up after conization.

Human papillomavirus (HPV) E6/E7 mRNA detection in cervical exfoliated cells: a potential triage for HPV-positive women

Cytology triage has been generally recommended for human papillomavirus (HPV)-positive women, but is highly dependent on well-trained cytologists. The present study was designed to explore whether HPV E6/E7 mRNA detection in cervical exfoliated cells can be a potential triage for HPV-positive women from a clinic-based population. Both the primary HPV testing and Papanicolaou (Pap) test were performed on all eligible HPV-positive women. HPV E6/E7 mRNA was detected by QuantiVirus^® HPV E6/E7 mRNA assay in cervical exfoliated cells. All HPV-positive women underwent colposcopy and further biopsy if indicated. The data were assessed by Pearson's Chi-squared test and the receiver operating characteristic curve. A total of 404 eligible HPV-positive women were enrolled. Positive rate of E6/E7 mRNA in high-grade squamous intraepithelial lesion (HSIL) cases was higher than that in low-grade squamous intraepithelial lesion (LSIL) or normal cases. There was no statistical difference found between mRNA and cytological testing with sensitivity (89.52% vs. 86.67%, P=0.671), specificity (48.96% vs. 48.96%, P=1.000), positive predictive value (39.00% vs. 38.24%, P=1.000), and negative predictive value (92.76% vs. 90.97%, P=0.678) for detecting ≥HSIL. HPV E6/E7 mRNA detection in cervical exfoliated cells shows the same performance as Pap triage for HSIL identification for HPV-positive women. Detection of HPV E6/E7 mRNA may be used as a new triage option for HPV-positive women.

Analytic and Diagnostic Performances of Human Papillomavirus E6/E7 mRNA Test on up-to 11-Year-Old Liquid-Based Cervical Samples. A Biobank-Based Longitudinal Study

Human Papillomavirus (HPV) E6/E7 mRNA test demonstrated high specificity in detecting HPV infections, but studies assessing its efficacy in terms of cancer risk stratification are lacking. Follow-up studies are arduous and expensive. Biobank would be the answer to the problem, although data investigating the effects of long-term storage on RNA preservation are still needed. We addressed these issues by retrieving 202 residual liquid-based cervical specimens, collected from 149 women attending cervical cancer screening during the years 2001–2012. Samples were stored in Adriatic Biobank at room temperature and without any handing. After calculation of RNA yield and purity, E6/E7 mRNA test was retrospectively performed on each samples, to assess analytic and diagnostic performances. Using automated extraction procedures, RNA of good quantity and quality was obtained. The mean value of RNA concentration was 27.5 ng/μL. The mean A260/A280 ratio was 2.1. An invalid mRNA test result was found in 11.9% of the specimens. Neither RNA integrity, nor analytic performances of mRNA test were influenced by the year of sample collection. In total, 62.4% of the specimens tested as mRNA positive; among these, 89.2% were CIN2+. E6/E7 mRNA was detected in all Squamous Cervical Cancer (SCC) cases. Percentage of positive samples increased with the severity of histological diagnosis. mRNA testing, showing specificity and predictive values of 75.6% and 84.4%, respectively, significantly improved the corresponding values for DNA testing. Thus, the reflex mRNA test was demonstrated to be suitable to triage women with persistent cervical lesions. A “one sample for all” approach is possible, with practical benefits for Biobank-based long-term longitudinal studies, diseases prevention, prediction, diagnosis and treatment.

RNA extraction method is crucial for human papillomavirus E6/E7 oncogenes detection

BACKGROUND

Human papillomavirus (HPV) DNA testing plays a main role in the management of cervical cancer, however to improve the specificity in cervical screening, there is a need to develop and validate different approaches that can identify women at risk for progressive disease. Nowadays, mRNA expression of viral E6 and E7 HPV oncogenes stands up as a potential biomarker to improve cervical screening. We aimed to validate a method for RNA extraction, detect HPV mRNA expression and, assess the relationship between E6/E7 mRNA expression and pathology of patients' lesions and progression.

METHODS

This study included 50 specimens that had been previously genotyped as HPV16, 18, 31, 33 and/or 45. Cervical swabs were extracted with three different RNA extraction methods -Nuclisens manual extraction kit (bioMérieux), High Pure Viral RNA Kit (Roche) and RNeasy Plus Mini kit (Qiagen)-, and mRNA was detected with NucliSens EasyQ HPV version 1 test (bioMérieux) afterwards. Association of oncogene expression with pathology and lesion progression was analyzed for each extraction method.

RESULTS

E6/E7 mRNA positivity rate was higher in samples analyzed with bioMérieux (62%), followed by Roche (24%) and Qiagen (6%). Women with lesions and lesion progression showed a higher prevalence of viral RNA expression than women that had not lesions or with lesion persistence. While bioMérieux revealed a higher sensitivity (77.27%), Roche presented a higher PPV (75%) and an increased specificity (89.28%).

CONCLUSIONS

Extraction methods based on magnetic beads provided better RNA yield than those based in columns. Both Nuclisens manual extraction kit (bioMérieux) and High Pure Viral RNA Kit (Roche) seemed to be adequate for E6/E7 mRNA detection. However, none of them revealed both high sensitivity and specificity values. Further studies are needed to obtain and validate a standard gold method for RNA expression detection, to be included as part of the routine cervical screening program.

A Low-Cost HPV Immunochromatographic Assay to Detect High-Grade Cervical Intraepithelial Neoplasia

Objective

To evaluate the reproducibility and accuracy of the HPV16/18-E6 test.

Methods

The study population was comprised of 448 women with a previously abnormal Pap who were referred to the Barretos Cancer Hospital (Brazil) for diagnosis and treatment. Two cervical samples were collected immediately before colposcopy, one for the hr-HPV-DNA test and cytology and the other for the HPV16/18-E6 test using high-affinity monoclonal antibodies (mAb). Women with a histologic diagnosis of cervical intraepithelial neoplasia grade 2 or 3 were considered to be positive cases. Different strategies using a combination of screening methods (HPV-DNA) and triage tests (cytology and HPV16/18-E6) were also examined and compared.

Results

The HPV16/18-E6 test exhibited a lower positivity rate compared with the HPV-DNA test (19.0% vs. 29.3%, p<0.001) and a moderate/high agreement (kappa = 0.68, 95%CI: 0.60–0.75). It also exhibited a significantly lower sensitivity for CIN2+ and CIN3+ detection compared to the HPV-DNA test and a significantly higher specificity. The HPV16/18-E6 test was no different from cytology in terms of sensitivity, but it exhibited a significantly higher specificity in comparison to ASCH+. A triage test after HPV-DNA detection using the HPV16/18-E6 test exhibited a significantly higher specificity compared with a triage test of ASCH+ to CIN2+ (91.8% vs. 87.4%, p = 0.04) and CIN3+ (88.6% vs. 84.0%, p = 0.05).

Conclusion

The HPV16/18-E6 test exhibited moderate/high agreement with the HPV-DNA test but lower sensitivity and higher specificity for the detection of CIN2+ and CIN3+. In addition, its performance was quite similar to cytology, but because of the structural design addressed for the detection of HPV16/18-E6 protein, the test can miss some CIN2/3+ lesions caused by other high-risk HPV types.

Human papillomavirus genotype distribution and E6/E7 oncogene expression in Turkish women with cervical cytological findings

BACKGROUND

Infection with certain human papillomavirus (HPV) genotypes is the most important risk factor related with cervical cancer. The objective of the present study was to investigate the prevalence of HPV infection, the distribution of HPV genotypes and HPV E6/E7 oncogene mRNA expression in Turkish women with different cervical cytological findings in Mersin province, Southern Turkey.

MATERIALS AND METHODS

A total of 476 cytological samples belonging to women with normal and abnormal cervical Pap smears were enrolled in the study. For the detection and genotyping assay, a PCR/direct cycle sequencing approach was used. E6/E7 mRNA expression of HPV-16, 18, 31, 33, and 45 was determined by type-specific real-time NASBA assay (NucliSENS EasyQ(®)HPV v1.1).

RESULTS

Of the 476 samples, 106 (22.3%) were found to be positive for HPV DNA by PCR. The presence of HPV was significantly more common (p<0.001) in HSIL (6/8, 75%) when compared with LSIL (6/14, 42.9%), ASC-US (22/74, 29.7%) and normal cytology (72/380, 18.9%). The most prevalent genotypes were, in descending order of frequency, HPV genotype 66 (22.6%), 16 (20.8%), 6 (14.2%), 31 (11.3%), 53 (5.7%), and 83 (4.7%). HPV E6/E7 oncogene mRNA positivity (12/476, 2.5%) was lower than DNA positivity (38/476, 7.9%).

CONCLUSIONS

Our data present a wide distribution of HPV genotypes in the analyzed population. HPV genotypes 66, 16, 6, 31, 53 and 83 were the predominant types and most of them were potential carcinogenic types. Because of the differences between HPV E6/E7 mRNA and DNA positivity, further studies are required to test the role of mRNA testing in the triage of women with abnormal cervical cytology or follow up of HPV DNA positive and cytology negative. These epidemiological data will be important to determine the future impact of vaccination on HPV infected women in our region.

E6/E7 mRNA testing for human papilloma virus-induced high-grade cervical intraepithelial disease (CIN2/CIN3): a promising perspective

Since the introduction of biomolecular testing for the identification of high-risk human papillomavirus DNA (hrHPV-DNA) in cervical cancer preventive strategies, many interesting aspects have emerged in this field; firstly, HPV-DNA testing has been demonstrated to have better sensitivity than conventional cytology in several settings: screening, triage of ASC-US and in follow-up after treatment. Despite this, some limitations of these new technologies have also been underlined: the major issue is the low specificity of the tests, which cannot discriminate between regressive and progressive infections. Thus, recent research has moved the attention towards novel markers of progression that could more precisely detect cases at real risk of cancer development. In view of the fact that progression to cancer is dependable of the E6/E7 proteins integration and transforming action, the overexpression of E6/E7 transcripts has been seen as a valuable marker of this risk. This review aims to summarise the literature data on this topic and to provide a clear view of the emerging perspectives.

Presence of High-Risk HPV mRNA in Relation to Future High-Grade Lesions among High-Risk HPV DNA Positive Women with Minor Cytological Abnormalities

OBJECTIVE

Continuous expression of E6- and E7-oncogenes of high-risk human papillomavirus (HPV) types is necessary for the development and maintenance of the dysplastic phenotype. The aim of the study was to determine the sensitivity and specificity of the APTIMA HPV mRNA assay (Hologic) in predicting future development of high-grade cervical intraepithelial neoplasia (CIN) among high-risk HPV-DNA-positive women with atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous epithelial lesion (LSIL) cytology.

METHODS

Archived SurePath cervical samples of women ≥ 35 years of age with high-risk HPV DNA-positive ASCUS (n = 211) or LSIL, (n = 131) were tested for the presence of high-risk HPV E6/E7 mRNA using the APTIMA HPV assay, and the women were monitored for development of histopathologically verified CIN2+.

RESULTS

Twenty-nine percent (61/211) of the women in the ASCUS group, and 34.3% (45/131) in the LSIL group developed CIN2+ within 4.5 years of follow-up. The prevalence of HPV mRNA was 90.0% (95% CI 85.9-94.0) among women with ASCUS and 95.4% (95% CI 91.8-99.0) among women with LSIL. The presence of HPV E6/E7 mRNA was associated with future development of CIN2+ among women with ASCUS and LSIL (p=0.02). The mRNA assay demonstrated high sensitivity in predicting future CIN2+ and CIN3 for index ASCUS (96.7%; 95% CI 87.6-99.4 and 100%; 95% CI 82.2-100, respectively) and LSIL (97.8%, 95% CI 86.8-99.9 and 100%, 95% CI 79.9-100, respectively). The corresponding specificity was low, 12.7% (95% CI 7.9-19.3) and 5.8% (95% CI 2.2-13.6), for future CIN2+, respectively. The negative predictive value of the HPV mRNA assay for detecting future CIN3 was 100%, since no mRNA-negative woman developed CIN3 (0/27) as compared to 13.6% (43/315) of the mRNA-positive women (p = 0.03).

CONCLUSION

The APTIMA mRNA assay demonstrated high sensitivity but low specificity in predicting future CIN2+ among women with minor cytological abnormalities. The assay had high negative predictive value for future CIN3, indicating that HPV-mRNA-negative women are at low risk of progression to high grade CIN.

Isothermal amplified detection of DNA and RNA

This review highlights various methods that can be used for a sensitive detection of nucleic acids without using thermal cycling procedures, as is done in PCR or LCR. Topics included are nucleic acid sequence-based amplification (NASBA), strand displacement amplification (SDA), loop-mediated amplification (LAMP), Invader assay, rolling circle amplification (RCA), signal mediated amplification of RNA technology (SMART), helicase-dependent amplification (HDA), recombinase polymerase amplification (RPA), nicking endonuclease signal amplification (NESA) and nicking endonuclease assisted nanoparticle activation (NENNA), exonuclease-aided target recycling, Junction or Y-probes, split DNAZyme and deoxyribozyme amplification strategies, template-directed chemical reactions that lead to amplified signals, non-covalent DNA catalytic reactions, hybridization chain reactions (HCR) and detection via the self-assembly of DNA probes to give supramolecular structures. The majority of these isothermal amplification methods can detect DNA or RNA in complex biological matrices and have great potential for use at point-of-care.

Comparison of the performance of the NucliSENS EasyQ HPV E6/E7 mRNA assay and HPV DNA chip for testing squamous cell lesions of the uterine cervix

This study aims to evaluate the clinical performance of the NucliSENS EasyQ assay and compare it with HPV DNA genotyping for the detection of high-grade squamous intraepithelial lesions (HSIL) and cancer in a Korean population. In 188 total thin prep samples, the remaining fluid after cytology slide preparation was tested with Goodgene HPV DNA chips and the NucliSENS EasyQ HPV E6/E7 messenger RNA (mRNA) assay. The sensitivity and specificity of each test were calculated with HSIL and squamous cell carcinoma (SCC) as the disease endpoint. Out of the 188 samples, 139 (74%) were positive for DNA of 14 HPV types, while 57 (30%) cases were positive for E6/E7 mRNA. The DNA test was positive in cytology cases of SCC, HSIL, and atypical squamous cell. The mRNA test yielded results of 75%, 74%, 60%, 56%, and 29% positivity in abnormal cytology cases of SCC, HSIL, atypical squamous cells - cannot exclude HSIL, atypical squamous cells of undetermined significance, and low-grade squamous intraepithelial lesion, respectively. In normal cytology cases, the positivity rates were 9% and 53% for the mRNA and DNA tests, respectively. For detection of HSIL and SCC, the sensitivity of the mRNA test was 74.36% and that of the DNA test was 100%, while the specificities of the tests were 85% and 40.83%, respectively. These findings suggest that the HPV E6/E7 mRNA assay can overcome the shortcoming of low specificity of DNA assays for clinical detection of high-grade cervical lesions and malignancies.

Use of the NucliSENS EasyQ HPV assay in the management of cervical intraepithelial neoplasia

Persistent infection by high-risk human papillomavirus is a necessary cause for cervical cancer. DNA-based human papillomavirus (HPV) assays show high sensitivity but poor specificity in detecting high-grade cervical lesions. Assays detecting mRNA of the oncoproteins E6 and E7 show higher specificity but lack either detection of all high-risk genotypes or the ability to specify the detected genotypes. The aim of this study was to evaluate the clinical performance of the NucliSENS EasyQ HPV assay in comparison with the Hybrid Capture 2 test (HC2) and the CLART Human Papillomavirus 2 assay (CLART), using a clinical cut-off of cervical intraepithelial neoplasia grade 2 or worse. In the 554 studied women, the lowest HPV positivity rate was detected for NucliSENS EasyQ HPV assay (55.1%), while HC2 and CLART showed similar results (HC2: 77.4%; CLART: 78.0%). In comparison with the other tests, the NucliSENS EasyQ HPV assay showed a lower clinical sensitivity (79.3% vs. 96.4% for HC2 and 95.9% for CLART) but a higher clinical specificity (72.6% vs. 42.8% for HC2 and 42.5% for CLART). Detection of E6/E7 mRNA transcripts may provide a higher specificity for cervical intraepithelial neoplasia grade 2 lesions or worse, since the oncogenic potential of HPV infection depends on the over-expression of these two oncoproteins.

Understanding HPV tests and their appropriate applications

Greater understanding of the role played by human papillomavirus (HPV) in the causation of disease has led to the development of an increasing number of HPV tests with different characteristics. The bewildering choice facing healthcare professionals and providers is daunting. Clearly, HPV testing is no longer simply of research interest, but can provide information that can be used for individual patient management and at the population level for cervical screening and vaccine surveillance. This review aims to provide the background to the development of HPV tests, to explain the different technologies and to discuss the challenges of the application of these optimally in the varied contexts of disease management. Few HPV tests are approved for clinical use and it is important that clinicians understand which test can be utilized, in what circumstances, with what specimens and the meaning of the report issued. HPV testing is no longer applicable only to cervical disease, and we have suggested additional areas, such as the oropharynx, in which HPV testing services might be implemented in the near future. New tests will continue to emerge and we have identified some of the indirect measures of HPV activity, or biomarkers, that could help in the risk stratification of HPV infection and associated disease. The challenges relating to the optimal application of the various HPV technologies are compounded by the lack of evidence regarding their performance in vaccinated populations. Currently published work, including modelling studies, has been undertaken in non-immunized populations. We therefore end by addressing the issues regarding appropriate strategies and tests for immunized populations.

Prospective evaluation of E6/E7 mRNA detection by the NucliSENS Easy Q HPV assay in a stepwise protocol

The objective of the study was to evaluate prospectively the added value of E6/E7 mRNA detection in a stepwise protocol. A total of 1,422 samples were collected over a period of 17 months. The samples were referred for human papillomavirus (HPV) genotyping if they showed cytological evidence of atypical squamous cells of undetermined significance, low- or high-grade squamous intraepithelial lesion. If one or more of HPV types 16, 18, 31, 33, or 45 were present, mRNA was analyzed by the NucliSENS EasyQ HPV assay. The genotypical distribution of high-risk HPV was very heterogeneous; HPV 16, 18, 31, 33, and 45 represented 20.2%, 3.4%, 10.8%, 3.4%, and 3.8% of HPV-positive samples, respectively. Follow-up data were available for 35 patients. Although over the half (51.4%) of follow-up samples showing HPV DNA/mRNA consensus evolved to cervical intraepithelial neoplastic lesions, 25.7% showed no progression to neoplasia despite mRNA positivity. However, the major concern was the group (14.3%) that showed progression to cervical intraepithelial neoplasia despite mRNA negativity: all but one of these cases had a high-risk HPV genotype other than the five included in the NucliSENS EasyQ HPV assay. Markedly, 66.7% of the discordant samples between colposcopy and histology that underestimated the degree of cervical dysplasia were found in this group. Close monitoring of high-risk HPV DNA-positive/mRNA-negative cases remains necessary, which leads to questions about the added value of the evaluated protocol.

Human papillomavirus testing versus repeat cytology for triage of minor cytological cervical lesions

BACKGROUND

Atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intra-epithelial lesions (LSIL) are minor lesions of the cervical epithelium, detectable by cytological examination of cells collected from the surface of the cervix of a woman.Usually, women with ASCUS and LSIL do not have cervical (pre-) cancer, however a substantial proportion of them do have underlying high-grade cervical intra-epithelial neoplasia (CIN, grade 2 or 3) and so are at increased risk for developing cervical cancer. Therefore, accurate triage of women with ASCUS or LSIL is required to identify those who need further management.This review evaluates two ways to triage women with ASCUS or LSIL: repeating the cytological test, and DNA testing for high-risk types of the human papillomavirus (hrHPV) - the main causal factor of cervical cancer.

OBJECTIVES

Main objective To compare the accuracy of hrHPV testing with the Hybrid Capture 2 (HC2) assay against that of repeat cytology for detection of underlying cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) or grade 3 or worse (CIN3+) in women with ASCUS or LSIL. For the HC2 assay, a positive result was defined as proposed by the manufacturer. For repeat cytology, different cut-offs were used to define positivity: Atypical squamous cells of undetermined significance or worse (ASCUS+), low-grade squamous intra-epithelial lesions or worse (LSIL+) or high-grade squamous intra-epithelial lesions or worse (HSIL+).Secondary objective To assess the accuracy of the HC2 assay to detect CIN2+ or CIN3+ in women with ASCUS or LSIL in a larger group of reports of studies that applied hrHPV testing and the reference standard (coloscopy and biopsy), irrespective whether or not repeat cytology was done.

SEARCH METHODS

We made a comprehensive literature search that included the Cochrane Register of Diagnostic Test Accuracy Studies; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (through PubMed), and EMBASE (last search 6 January 2011). Selected journals likely to contain relevant papers were handsearched from 1992 to 2010 (December). We also searched CERVIX, the bibliographic database of the Unit of Cancer Epidemiology at the Scientific Institute of Public Health (Brussels, Belgium) which contains more than 20,000 references on cervical cancer.More recent searches, up to December 2012, targeted reports on the accuracy of triage of ASCUS or LSIL with other HPV DNA assays, or HPV RNA assays and other molecular markers. These searches will be used for new Cochrane reviews as well as for updates of the current review.

SELECTION CRITERIA

Studies eligible for inclusion in the review had to include: women presenting with a cervical cytology result of ASCUS or LSIL, who had undergone both HC2 testing and repeat cytology, or HC2 testing alone, and were subsequently subjected to reference standard verification with colposcopy and colposcopy-directed biopsies for histologic verification.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data from the selected studies, and obtained additional data from report authors.Two groups of meta-analyses were performed: group I concerned triage of women with ASCUS, group II concerned women with LSIL. The bivariate model (METADAS-macro in SAS) was used to assess the absolute accuracy of the triage tests in both groups as well as the differences in accuracy between the triage tests.

MAIN RESULTS

The pooled sensitivity of HC2 was significantly higher than that of repeat cytology at cut-off ASCUS+ to detect CIN2+ in both triage of ASCUS and LSIL (relative sensitivity of 1.27 (95% CI 1.16 to 1.39; P value < 0.0001) and 1.23 (95% CI 1.06 to 1.4; P value 0.007), respectively. In ASCUS triage, the pooled specificity of the triage methods did not differ significantly from each other (relative specificity: 0.99 (95% CI 0.97 to 1.03; P value 0.98)). However, the specificity of HC2 was substantially, and significantly, lower than that of repeat cytology in the triage of LSIL (relative specificity: 0.66 (95% CI 0.58 to 0.75) P value < 0.0001).

AUTHORS' CONCLUSIONS

HPV-triage with HC2 can be recommended to triage women with ASCUS because it has higher accuracy (significantly higher sensitivity, and similar specificity) than repeat cytology. When triaging women with LSIL, an HC2 test yields a significantly higher sensitivity, but a significantly lower specificity, compared to a repeat cytology. Therefore, practice recommendations for management of women with LSIL should be balanced, taking local circumstances into account.

Type-specific human papillomavirus E6/E7 mRNA detection by real-time PCR improves identification of cervical neoplasia

DNA-based human papillomavirus (HPV) assays show high sensitivity but poor specificity in detecting high-grade cervical lesions. Assays detecting mRNA of the oncoproteins E6 and E7 show higher specificity but lack either detection of all high-risk HPV genotypes or the capacity to specify the detected genotypes. Therefore, a real-time PCR assay detecting type-specific E6/E7 mRNA was developed and the clinical performance evaluated. A total of 210 cervical LBC (liquid-based cytology) samples from 204 women were analyzed for HPV DNA and mRNA with the in-house real-time PCR as well as PreTect HPV-Proofer. The sensitivity of real-time PCR mRNA detection to identify histologically confirmed CIN2+ (cervical intraepithelial neoplasia, grade 2 or higher) was 0.91, compared to 0.95 for DNA analysis. The specificity was 0.68 compared to 0.38, and the positive predictive value (PPV) was higher for mRNA (0.67 versus 0.52) without any loss in negative predictive value (NPV). The sensitivity of the real-time PCR mRNA test was somewhat higher than that for PreTect HPV-Proofer (0.83 versus 0.75) in analyses for the same genotypes. The specificities were similar (0.76 versus 0.77). In analyses for mRNA of the eight most common genotypes in cervical cancer (HPV16, -18, -31, -33, -35, -45, -52, and -58), the sensitivity of detection of CIN2+ lesions was 0.87 and the specificity 0.74, with a PPV of 0.70. In conclusion, real-time PCR for detection of HPV E6/E7 mRNA transcripts can be a sensitive and specific tool in screening and investigation of cervical neoplasia. The composition of HPV types in mRNA testing needs to be further investigated to optimize sensitivity and specificity.

Looking ahead: a case for human papillomavirus testing of self-sampled vaginal specimens as a cervical cancer screening strategy

Even in the era of highly effective human papillomavirus (HPV) prophylactic vaccines, substantial reduction in worldwide cervical cancer mortality will only be realized if effective early detection and treatment of the millions of women already infected and the millions who may not receive vaccination in the next decade can be broadly implemented through sustainable cervical cancer screening programs. Effective programs must meet three targets: (i) at least 70% of the targeted population should be screened at least once in a lifetime, (ii) screening assays and diagnostic tests must be reproducible and sufficiently sensitive and specific for the detection of high-grade precursor lesions (i.e., CIN21), and (iii) effective treatment must be provided. We review the evidence that HPV DNA screening from swabs collected by the women in their home or village is sufficiently sound for consideration as a primary screening strategy in the developing world, with sensitivity and specificity for detection of CIN21 as good or better than Pap smear cytology and VIA. A key feature of a self-collected HPV testing strategy (SC-HPV) is the move of the primary screening activities from the clinic to the community. Efforts to increase the affordability and availability of HPV DNA tests, community education and awareness, development of strong partnerships between community advocacy groups, health care centers and regional or local laboratories, and resource appropriate strategies to identify and treat screen-positive women should now be prioritized to ensure successful public health translation of the technologic advancements in cervical cancer prevention.

Miniaturized isothermal nucleic acid amplification, a review

Micro-Total Analysis Systems (µTAS) for use in on-site rapid detection of DNA or RNA are increasingly being developed. Here, amplification of the target sequence is key to increasing sensitivity, enabling single-cell and few-copy nucleic acid detection. The several advantages to miniaturizing amplification reactions and coupling them with sample preparation and detection on the same chip are well known and include fewer manual steps, preventing contamination, and significantly reducing the volume of expensive reagents. To-date, the majority of miniaturized systems for nucleic acid analysis have used the polymerase chain reaction (PCR) for amplification and those systems are covered in previous reviews. This review provides a thorough overview of miniaturized analysis systems using alternatives to PCR, specifically isothermal amplification reactions. With no need for thermal cycling, isothermal microsystems can be designed to be simple and low-energy consuming and therefore may outperform PCR in portable, battery-operated detection systems in the future. The main isothermal methods as miniaturized systems reviewed here include nucleic acid sequence-based amplification (NASBA), loop-mediated isothermal amplification (LAMP), helicase-dependent amplification (HDA), rolling circle amplification (RCA), and strand displacement amplification (SDA). Also, important design criteria for the miniaturized devices are discussed. Finally, the potential of miniaturization of some new isothermal methods such as the exponential amplification reaction (EXPAR), isothermal and chimeric primer-initiated amplification of nucleic acids (ICANs), signal-mediated amplification of RNA technology (SMART) and others is presented.

Methods for HPV detection in exfoliated cell and tissue specimens

Given the causal involvement of high-risk human papillomaviruses (HPVs) in cervical cancer and a subset of squamous cell carcinomas of other anogenital regions as well as the oropharynx, much attention has been focused on the development and application of HPV detection assays. HPV detection assays are almost exclusively based on the detection of viral nucleic acids, mostly viral DNA. The HPV detection methods that are nowadays in use can broadly be subdivided into target amplification methods and signal amplification methods. In this review, several principles of various methodologies are explained and examples of some commonly used HPV detection assays are given. In addition, attention is paid to the use of HPV assays for detecting clinically meaningful HPV infections, i.e. infections related to (pre)cancerous lesions, e.g. cervical cancer screening purposes. For the latter, it is important that HPV tests are clinically validated according to validation strategies as outlined in guidelines.

Nucleic acid sequence-based amplification assay for human papillomavirus mRNA detection and typing: evidence for DNA amplification

Human papillomavirus (HPV) E6/E7 mRNA has been proposed as a more specific marker for cervical dysplasia and cancer than HPV DNA. This study evaluated the RNA specificity of nucleic acid sequence-based amplification (NASBA)-based HPV detection using HPV DNA plasmids (HPV type 16 [HPV16], HPV18, HPV31, HPV33, and HPV45) and nucleic acid extracts of several cell lines, which were systematically subjected to enzymatic treatments with DNase and RNase. HPV plasmid dilutions (10(6) to 10(0) copies/microl) and nucleic acid extracts (total DNA, RNA-free DNA, total RNA, and DNA-free RNA) of unfixed and fixed (PreServCyt and SurePath) HaCaT, HeLa, and CaSki cells were tested with the NucliSENS EasyQ HPV test. The RNA-free DNA extracts of HeLa and CaSki cells could be amplified by HPV18 and -16 NASBA, respectively. Fixation of the cells did not influence NASBA. All HPV plasmids could be detected with NASBA. Based on the plasmid dilution series, a lower detection limit of 5 x 10(3) HPV DNA copies could be determined. Our study identified viral double-stranded DNA as a possible target for NASBA-based HPV detection. The differences in diagnostic accuracy between the NASBA-based tests and conventional HPV DNA detection assays seem to be attributable not to the more specific amplification of viral mRNA but to the limited type range and the lower analytical sensitivity for HPV DNA.