Comparison of the Abbott RealTime High-Risk Human Papillomavirus (HPV), Roche Cobas HPV, and Hybrid Capture 2 assays to direct sequencing and genotyping of HPV DNA

Infection with high-risk (HR) human papillomavirus (HPV) genotypes is an important risk factor for cervical cancers. We evaluated the clinical performances of two new real-time PCR assays for detecting HR HPVs compared to that of the Hybrid Capture 2 test (HC2). A total of 356 cervical swab specimens, which had been examined for cervical cytology, were assayed by Abbott RealTime HR and Roche Cobas HPV as well as HC2. Sensitivities and specificities of these assays were determined based on the criteria that concordant results among the three assays were regarded as true-positive or -negative and that the results of genotyping and sequencing were considered true findings when the HPV assays presented discrepant results. The overall concordance rate among the results for the three assays was 82.6%, and RealTime HR and Cobas HPV assays agreed with HC2 in 86.1% and 89.9% of cases, respectively. The two real-time PCR assays agreed with each other for 89.6% of the samples, and the concordance rate between them was equal to or greater than 98.0% for detecting HPV type 16 or 18. HC2 demonstrated a sensitivity of 96.6% with a specificity of 89.1% for detecting HR HPVs, while RealTime HR presented a sensitivity of 78.3% with a specificity of 99.2%. The sensitivity and specificity of Cobas HPV for detecting HR HPVs were 91.7% and 97.0%. The new real-time PCR assays exhibited lower sensitivities for detecting HR HPVs than that of HC2. Nevertheless, the newly introduced assays have an advantage of simultaneously identifying HPV types 16 and 18 from clinical samples.     

Comparison of the Roche Cobas® 4800 HPV assay to Digene Hybrid Capture 2, Roche Linear Array and Roche Amplicor for Detection of High-Risk Human Papillomavirus Genotypes in Women undergoing treatment for cervical dysplasia

BackgroundThe recently FDA (U.S. food and drug administration) approved Roche Cobas^® 4800 (Cobas) human papillomavirus (HPV) has limited performance data compared to current HPV detection methods for test of cure in women undergoing treatment for high grade lesions.ObjectiveEvaluation of Cobas HPV assay using historical samples from women undergoing treatment for cervical dysplasia.Study designA selection of 407 samples was tested on the Cobas assay and compared to previous results from Hybrid Capture 2, HPV Amplicor and Roche Linear Array.ResultsOverall, a correlation between high-risk HPV positivity and high grade histological diagnosis was 90.6% by the Cobas, 86.1% by Hybrid Capture 2, 92.9% by HPV Amplicor and 91.8% by Roche Linear Array.ConclusionThe Cobas HPV assay is comparative to both the HPV Amplicor and Roche Linear Array assays and better than Hybrid capture 2 assay in the detection of High-Risk HPV in women undergoing treatment for cervical dysplasia.     

Utility of the Roche Cobas 4800 for detection of high-risk human papillomavirus in formalin-fixed paraffin-embedded oropharyngeal squamous cell carcinoma

Clinical laboratories are expected to reliably identify human papilloma virus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) for prognostic and potential therapeutic applications. In addition to surrogate p16 immunohistochemistry (IHC) testing, DNA-based HPV-specific testing strategies are widely utilized. Recognizing the efficiency of the Roche Cobas 4800 platform for testing gynecological cytology specimens for high-risk HPV, we elected to evaluate the potential utility of this platform for testing formalin-fixed paraffin-embedded (FFPE) OPSCC tissue. Using the Roche Linear Array assay for comparison, we tested twenty-eight samples (16 primary OPSCC, 2 lymph node metastases from primary OPSCC, 1 oral tongue carcinoma, 3 benign squamous papillomas, and 3 non-oropharyngeal carcinoma tissues). Excluding two invalid results, the Roche Cobas 4800 testing resulted in excellent inter-assay concordance (25/26, 96.2%) and 100% concordance for HPV-16/HPV-18 positive samples. This data suggests that the Roche Cobas 4800 platform may be a cost-effective method for testing OPSCC FFPE tissues in a clinical molecular pathology laboratory setting.     

Comparison of the Cobas 4800 HPV Test and the Seeplex HPV4A ACE with the Hybrid Capture 2 Test

Background: It is well-known that persistent cervical infections with high-risk human papillomavirus (HPV) are related to the development of high-grade cervical intraepithelial neoplasia and invasive cervical cancer and that infection with HPV 16 and HPV 18 accounts for approximately 70% of all cases of invasive cervical cancer.Methods: We performed 3 HPV molecular tests―the Cobas 4800 HPV test, the Seeplex HPV4A ACE, and the hybrid capture 2 (HC2) test―in 146 cervical swab samples to compare between these three tests.Results: There was a concordance rate of 82.8% between the results of the Cobas 4800 HPV and the HC2 test and a concordance rate of 84.9% between the results of the Seeplex HPV4A ACE and the HC2 test. Between the Cobas 4800 HPV test and the Seeplex HPV4A ACE, there was a concordance rate of 89.6% in the detection of high-risk HPV between the results and a concordance rate of 98.7% in the detection of HPV 16 or 18. When an abnormal Pap test was defined as ≥low grade squamous intraepithelial lesion (LSIL), the sensitivity of the Cobas 4800 HPV test, the Seeplex HPV4A ACE and the HC2 test were 71.1%, 80.0%, and 88.9%, respectively, while their specificities were 76.4%, 74.5%, and 67.9%, respectively.Conclusions: The results of this study suggest that the Cobas 4800 HPV test and the Seeplex HPV4A ACE may be as effective as the HC2 test in detecting HR HPV and that the concordance between the results of the Cobas 4800 HPV test and the Seeplex HDV4A ACE may be higher in the detection of HPV 16 and HPV18 than concerning high-risk HPV.     

Comparison of the Roche Cobas® 4800 HPV assay to Roche Amplicor for detection of high-risk human papillomavirus

Roche Amplicor HPV (AMP) had previously been used for detection of high-risk human papillomavirus (HR-HPV) in epidemiological and clinical studies. As this assay is no longer available, we compared its performance using PreservCyt samples from women aged of 18–24 years attending for routine cervical cytology screening to Roche Cobas® 4800 (Cobas) to determine if subsequent studies could continue using the Cobas assay. Overall 507 samples were tested on Cobas and compared to previous AMP results, with discrepant samples tested on Roche Linear Array. Results: Overall, agreement between the Cobas and AMP for the presence of HR HPV types was very high (κ?=?0.81) (95 % CI: 0.76 - 0.87) with percentage agreement of 91.57 %. Cobas is comparable to AMP for the detection of HR-HPV types in a community recruited cohort of healthy women.     

Evaluation of a Newly Developed GenoArray Human Papillomavirus (HPV) Genotyping Assay and Comparison with the Roche Linear Array HPV Genotyping Assay

Persistent infection with high-risk types of human papillomavirus (HPV) is a necessary step in the development of cervical cancer. The incorporation of HPV detection into cervical screening programs may improve the ability to identify women at risk of cervical cancer. We recently evaluated the performance characteristics of a newly developed HPV detection assay, the GenoArray (GA) genotyping assay, for the detection of HPV infections by comparing it with the commercial Roche Linear Array (LA) HPV genotyping assay. The GA assay has an analytical sensitivity for the detection of HPV types 16 (HPV-16) and HPV-18 of as few as 10 to 50 copies, and its reproducibility is adequate. The GA and LA assays showed no significant difference in the rates of detection of genotypes detected by both HPV genotyping assays and oncogenic genotypes, and the interassay agreement was excellent. The GA and LA assays revealed either concordant or compatible genotyping results for 97.5% of the samples and discordant results for only eight (2.5%) samples. Compatible results were also observed for the detection of single or multiple HPV infections and the detection of most of the genotypes. The GA assay also demonstrated good clinical performance characteristics when the comparisons were carried out with clinical subgroups of samples from patients with normal cytologies, low-grade or high-grade squamous intraepithelial lesions, and cancers. Therefore, the GA assay appears to be highly sensitive and specific for the genotyping of HPV. It has the advantage that it specifically detects HPV-52, which overcomes a limitation of the LA assay, and hence, it has potential value for use for genotyping, especially in regions where HPV-52 has a high prevalence.Human papillomavirus (HPV) is the main etiological agent for the development of cervical cancer. Persistent infection with high-risk (HR) HPV types is recognized as a necessary step in the progression to neoplastic disease (26). Tests for HPV DNA have shown encouraging results when they are used in conjunction with the traditional cytology screening method (3, 7, 8). Many molecular methods for testing for HPV are currently available. The Digene/Hybrid Capture II (HC II) commercial HPV detection kit and the Cervista HPV HR and Cervista 16/18 tests are approved by the FDA for use for routine screening for HPV (9, 19). However, both the HC II and the Cervista HPV HR assays are unable to discriminate specific genotypes or to identify infections involving multiple genotypes, and the Cervista assay detects only two HPV types (types 16 and 18). Recent studies have suggested that different high-risk HPV types have different oncogenic potentials (5). Besides the clinical aspect, HPV genotyping is also a key part of epidemiological studies of HPV infections worldwide.A number of PCR-based HPV genotyping assays have been developed to amplify HPV DNA, followed by reverse hybridization against immobilized genotype-specific probes, allowing the simultaneous identification of a broad range of anogenital HPV genotypes. However, the different assays have potential variations in their abilities to detect different HPV types due to their different analytical sensitivities and specificities and their failure to detect specific variants (2, 17, 20).The HPV GenoArray (GA) test (Hybribio Ltd., Hong Kong) is a newly developed PCR-based HPV genotyping assay. It utilizes L1 consensus primers to simultaneously amplify 21 HPV genotypes, followed by flowthrough hybridization with immobilized genotype-specific probes. It is marked as Conformité Européenne (CE) for use in Europe and is currently being used in some hospitals in China.The present study was designed to evaluate the analytical and clinical performance characteristics of the Hybribio GA test, and the level of concordance of the genotypes detected by the GA test was compared to that of the Roche Linear Array (LA) HPV test. We focused on interassay agreement for overall HPV DNA detection and for the detection of HPV oncogenic risk types. We also assessed the interassay agreement for type-specific as well as single and multiple HPV infections.     

Stability of Cervical Specimens in SurePath Medium for Human Papillomavirus Testing with the Roche cobas 4800 Assay

The stability of cervical specimens in SurePath preservative fluid for human papillomavirus (HPV) testing with Roche cobas 4800 was determined using a panel of 308 pooled specimens from a colposcopy referral population. The SurePath specimens appeared to be stable for up to 10 weeks at ambient temperature for HPV testing with cobas 4800.     

Comparison of the cobas Human Papillomavirus (HPV) test with the hybrid capture 2 and linear array HPV DNA tests

The cobas human papillomavirus (HPV) test (cobas) was recently approved by the U.S. Food and Drug Administration (FDA) and identifies HPV16 and HPV18 separately as well as detecting a pool of 11 HR-HPV genotypes (HPV31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -68) and also HPV66. We compared cobas, Linear Array (LA), and Hybrid Capture 2 (HC2) assays for detection of carcinogenic HPV DNA, and cobas and LA for detection of HPV16 and HPV18 DNA, among the first 1,852 women enrolled in the HPV Persistence and Progression Cohort (PaP Cohort) study. Specimens were tested by all 3 assays 1 year after an HC2-positive result. In 1,824 specimens with cobas results, cobas had an 85.9% agreement with HC2 and 91.0% agreement with LA for carcinogenic HPV detection. When results between cobas and HC2 disagreed, cobas tended to call more women HPV positive (P < 0.01). Categorizing cobas and LA results hierarchically according to cancer risk (HPV16, HPV18, other carcinogenic HPV genotypes, or carcinogen negative), there was a 90% agreement for all categories of HPV (n = 1,824). We found good agreement between the two U.S. FDA-approved HPV tests, with discrepancies between the two assays due to specific characteristics of the individual assays. Additional studies are needed to compare HC2 and cobas for detecting and predicting CIN3 to understand the clinical implications of the discrepant test results between the two tests.     

Clinical Performance of Roche Cobas 4800 HPV Test

Evaluation of the Cobas 4800 test demonstrated that Cobas had a low rate of cross-reactivity with low-risk human papillomavirus (lrHPV), a 3.74% disconcordance rate between prealiquots and postaliquots, and failure rates of 4.57% and 1.16%, respectively, after vortexing and swirling. This study demonstrated that the Cobas test has good sensitivity, accuracy, and reproducibility for detecting 14 high-risk HPV (hrHPV) genotypes.     

The performance of human papillomavirus DNA detection with type 16/18 genotyping by hybrid capture in primary test of cervical cancer screening: a cross-sectional study in 10,669 Chinese women

ObjectivesWe aimed to assess the performance of DH3 human papillomavirus (HPV) assay, a newly developed hybrid capture technique that detects 14 high-risk HPVs with type 16/18 genotyping, as a primary test in cervical cancer screening.MethodsIn total 11,356 Chinese women aged 21–65 years participated in a cervical cancer screening programme using cytology (Thinprep, Hologic) and HPV testing (Cobas 4800 Test, Roche). Residual samples were used to detect HPV by DH3 HPV.ResultsIn total 10,669 women with valid results were included in the study. Of those, 135 were diagnosed as CIN2+, and 83 were diagnosed as CIN3+; 1056 women (9.9%) were DH3 HPV-positive and 255 (2.4%) of those were 16/18-positive, while 990 (9.3%) women were Cobas HPV-positive and 243 (2.3%) of those were 16/18-positive. DH3 HPV was non-inferior to Cobas HPV in identifying CIN1− and CIN2+ using predetermined thresholds (both p < 0.001). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of DH3 HPV were 93.3% (95% confidence interval [CI] = 87.7–96.9), 91.2% (95%CI = 90.6–91.7), 12.0% (95%CI = 10.1–14.1) and 99.9% (95%CI = 99.8–100), respectively, similar to those of Cobas HPV (91.1%, 95%CI = 85.0–5.3; 91.8%, 95%CI = 91.2–92.3; 12.5%, 95%CI = 10.5–14.7; and 99.9%, 95%CI = 99.8–99.9, respectively), in identifying CIN2+ (all p > 0.05). When DH3 HPV and Cobas HPV were respectively used as primary testing in screening strategy, the performance of two strategies were similar in identifying CIN2+. The results were similar in identifying CIN3+.ConclusionOur data suggest that DH3 HPV performs similarly to Cobas HPV in identifying high-grade CIN in cervical cancer screening.     

Types of Human Papillomavirus Observed in Hospital-Based Population

Background and Objectives: Human papillomavirus (HPV) is the causative agent of cervical cancer, a major cause of cancer mortality in Indian women. The current study was undertaken to add information to the existing data on HPV type distribution in Indians, in an attempt to document HPV types for future vaccination programme, if any. Materials and Methods: HPV infection was screened in 223 cervical cancer cases and 2408 healthy women without cancer and cervical intraepithelial neoplasia (control). HPV was typed using polymerase chain reaction, Southern hybridisation using specific probes and HPV GenoArray (Hybribio) test. Results: HPV DNA was found in 92.8% of cases and 7.3% of controls. Of the 383 HPV-infected women, 30.0% had single infection; 50.9% had multiple infections (two or more types) and 19.1% were infected with HPV types other than HPV-16, -18, -6 and -11. Besides HPV-16, HPV-51 and HPV-33 were also seen as single infection in cases. In cases, HPV-18 or its homologous HPV-45 was always present as co-infection with HPV-16 or with other high-risk type. Binary logistic regression (backward) analysis highlighted significant association of age, parity and socioeconomic status with HPV infection. The present study highlighted the presence of multiple HPV infection (186 of 207, 89.9%) along with HPV-16 in women with cervical cancer. In control, 27.3% were co-infected with other sexually transmitted infections, while Chlamydia trachomatis infection was seen in 13% of cases. Conclusions: The study highlighted the type of HPV infection seen among the hospital-based population. For better screening, HPV tests available in the market should include all the types seen in the population.     

High-risk human papillomavirus testing in women with ASC-US cytology: results from the ATHENA HPV study

This study evaluated the clinical performance of the cobas 4800 HPV Test (Roche Molecular Systems, Pleasanton, CA) for high-risk human papillomavirus (HR-HPV) testing with individual HPV-16/HPV-18 genotyping in women 21 years or older with atypical squamous cells of undetermined significance (ASC-US). Women (N = 47,208) were recruited in the United States during routine screening, and liquid-based cytology and HPV testing were performed. The ASC-US prevalence was 4.1% (1,923/47,208), and 1,578 women underwent colposcopy with valid results. The cobas 4800 HPV Test demonstrated performance comparable to the Hybrid Capture 2 test (QIAGEN, Gaithersburg, MD) for the detection of cervical intraepithelial neoplasia (CIN) grade 2 or worse and grade 3 or worse. HPV-16/HPV-18+ women had a greater absolute risk of CIN 2 or worse compared with pooled HR-HPV+ and HR-HPV- women (24.4%, 14.0%, and 0.8%, respectively). The cobas 4800 HPV Test is clinically validated for ASC-US triage. HPV-16/HPV-18 genotyping can identify women at highest risk for high-grade cervical disease, and this additional risk stratification may be used in formulating patient management decisions.     

Comparative Evaluation of Three Commercial Systems for Detection of High-Risk Human Papillomavirus in Cervical and Vaginal ThinPrep PreservCyt Samples and Correlation with Biopsy Results

Genital human papillomavirus (HPV) is the etiologic agent of more than 99% of all cervical cancers worldwide, with 14 genotypes being considered oncogenic or “high risk” because of their association with severe dysplasia and cervical carcinoma. Among these 14 high-risk types, HPV-16 and -18 account for approximately 70% of cervical cancers. The aim of this study was to evaluate three FDA-approved HPV nucleic acid-based tests for the ability to predict high-grade cervical intraepithelial neoplasias (CIN2 or worse) in corresponding tissue biopsy specimens. Residual specimens (total n = 793, cervical n = 743, vaginal n = 50) collected in ThinPrep PreservCyt medium with a cytologic result of ≥atypical squamous cells of undetermined significance were tested by the Hybrid Capture 2 (HC2) assay (Qiagen, Gaithersburg, MD), the cobas HPV test (Roche Diagnostics, Indianapolis, IN), and the APTIMA HPV assay (Hologic, San Diego, CA). Genotyping for HPV-16 and HPV-18 was simultaneously performed by the cobas HPV test. Results were compared to cervical or vaginal biopsy findings, when they were available (n = 350). Among the 350 patients with corresponding biopsy results, 81 (23.1%) showed ≥CIN2 by histopathology. The ≥CIN2 detection sensitivity was 91.4% by the cobas and APTIMA assays and 97.5% by HC2 assay. The specificities of the cobas, APTIMA, and HC2 assays were 31.2, 42.0, and 27.1%, respectively. When considering only positive HPV-16 and/or HPV-18 genotype results, the cobas test showed a sensitivity and a specificity of 51.9 and 86.6%, respectively. While the HC2, cobas, and APTIMA assays showed similar sensitivities for the detection of ≥CIN2 lesions, the specificities of the three tests varied, with the greatest specificity (86.6%) observed when the HPV-16 and/or HPV-18 genotypes were detected.     

The clinical performance of human papillomavirus genotyping using PANArray HPV chip: Comparison to ThinPrep cytology alone and co-testing

Recently, a high-risk human papillomavirus (HR-HPV) detecting assay alone could be used as a first-line screening tool for cervical cancer, although the test system has been limited to the Cobas 4800 HPV test. However, the screening efficiency of the HPV chip, which is widely used in Eastern Asia because of the high prevalence of non16/18 HR-HPV genotypes, has not been well elucidated. After selecting 300 women who were co-tested using the PANArray HPV chip and the ThinPrep assay and had confirmed histological diagnoses, we evaluated the diagnostic accuracy of the PANArray HPV test based on direct sequencing and clinical performance compared to the ThinPrep alone and co-testing. HR-HPVs were identified in 212 (70.7 %) patients by the PANArray HPV test. The results of the PANArray HPV test and direct sequencing for detecting HR-HPVs were in almost perfect agreement, consistent in 95.3 % of the cases (k = 0.89). HR-HPVs were more commonly detected by the PANArray HPV assay in patients with high-grade squamous intraepithelial lesions (HSILs) or worse (p < 0.001, both) by cytological and histological examinations. The PANArray HPV test had higher sensitivity (91.7 %) than the ThinPrep (52.6 %) but co-testing increased the sensitivity for predicting HSIL or worse cervical lesions to 99.2 %. In conclusion, the PANArray HPV test accurately detected HR-HPVs determined by cytological and histological examinations to be HSIL or worse cervical lesions. The PANArray HPV assay alone was more sensitive than the ThinPrep alone for detecting HSIL or worse cervical lesions, however, co-testing enhanced the sensitivity. Co-testing is more useful for screening HSIL or worse lesions than use of either the ThinPrep or PANArray HPV genotyping alone.     

Comparison of the Novel Human Papillomavirus 4 Auto-capillary Electrophoresis Test with the Hybrid Capture 2 Assay and with the PCR HPV Typing Set Test in the Detection of High-Risk HPV Including HPV 16 and 18 Genotypes in Cervical Specimens

The aim of this study was to compare the novel human papillomavirus (HPV) detection method, the HPV 4 Auto-capillary Electrophoresis (ACE) test with the hybrid capture (HC) 2 assay for the detection of high-risk HPVs. In addition, we compared the HPV 4 ACE test with the polymerase chain reaction HPV Typing Set test for the detection of HPV 16 and HPV 18 genotypes. One hundred ninety-nine cervical swab samples obtained from women with previous abnormal Pap smears were subjected to testing with the three HPV tests. The HPV 4 ACE test and the HC 2 assay showed substantial agreement for detection of high-risk HPVs (85.4%, kappa=0.71). The HPV 4 ACE test also showed substantial agreement with the PCR HPV Typing Set test in the detection of HPV 16 and HP V 18 genotypes (89.9%, kappa=0.65). In correlation with cytologic results, the sensitivities and specificities of the HPV 4 ACE test and HC 2 assay were 92.9% vs. 92.9% and 48.1% vs. 50.8%, respectively, when high-grade squamous intraepithelial lesions were regarded as abnormal cytologies. The novel HPV 4 ACE test is a valuable tool for the detection of high-risk HPVs and for genotyping of HPV 16 and HPV 18.     

Comparison of Human Papillomavirus Detection by Aptima HPV and cobas HPV Tests in a Population of Women Referred for Colposcopy following Detection of Atypical Squamous Cells of Undetermined Significance by Pap Cytology

Few studies have compared the cobas HPV test to the Aptima HPV assay (AHPV) and the Aptima HPV 16 18/45 genotype assay (AHPV GT) for high-risk human papillomavirus (hrHPV) detection, clinical performance in detecting cervical intraepithelial neoplasia grade 2 (CIN2) or more severe (CIN2+) diagnoses, and risk stratification by partial HPV genotyping. The cobas HPV test is a DNA test that separately and concurrently detects HPV16, HPV18, and a pool of 12 other hrHPV types. AHPV is an RNA test for a pool of 14 hrHPV genotypes, and AHPV GT is an RNA test run on AHPV-positive results to detect HPV16 separately from HPV18 and HPV45, which are detected together. In a population of patients (n = 988) referred for colposcopy because of a cervical Pap cytology result of atypical squamous cells of undetermined significance (ASC-US), a cervical scrape specimen was taken, placed into a ThinPrep Pap test vial containing PreservCyt liquid cytology medium, and tested in a blinded fashion with cobas and AHPV and with AHPV GT for AHPV-positive results. The final diagnoses were based on a consensus panel review of the biopsy specimen histology. AHPV and cobas were equally sensitive for CIN2+ diagnoses (89.4% each; P = 1.000), and AHPV was more specific than cobas (63.1% versus 59.3%; P ≤ 0.001). The percent total agreement, percent positive agreement, and kappa value were 90.9%, 81.1%, and 0.815, respectively. Risk stratification using partial HPV genotyping was similar for the two assays. AHPV and AHPV GT had similar sensitivity and risk stratification to cobas HPV, but they were more specific than cobas HPV.     

Prevalence and distribution of single and multiple HPV infections in cytologically abnormal cervical samples from Italian women

The prevalence of single and multiple HPV infections was assessed over a cohort of 213 women with cytological abnormalities and its association with cervical neoplasia established. Roche linear array HPV genotyping test was used to identify HPV genotypes. The most prevalent HPV genotypes in cervical cancer samples were HPV16 (61.2%), HPV52 (16.1%), HPV18 (12.9%) and HPV 31 (9.6%). Multiple HR and LR HPV infections, comprising between two and 5+ HPV types, were identified in 49.7% of samples, with a significantly lower number in severe dysplasia and cervical cancer samples (p<0.05). These results seem to indicate that detection of multiple HPV infection with HR-HPV types is not significantly better as a predictor of cervical cancer than single HR-HPV infection, though further longitudinal studies are needed to better clarify the relevance of these infections to the progression of cervical neoplasia.     

Cross-Reactivity,Epitope Spreading,and De Novo Immune Stimulation Are Possible Mechanisms of Cross-Protection of Nonvaccine Human Papillomavirus (HPV) Types in Recipients of HPV Therapeutic Vaccines

Numerous versions of human papillomavirus (HPV) therapeutic vaccines designed to treat individuals with established HPV infection, including those with cervical intraepithelial neoplasia (CIN), are in development because approved prophylactic vaccines are not effective once HPV infection is established. As human papillomavirus 16 (HPV-16) is the most commonly detected type worldwide, all versions of HPV therapeutic vaccines contain HPV-16, and some also contain HPV-18. While these two HPV types are responsible for approximately 70% of cervical cancer cases, there are other high-risk HPV types known to cause malignancy. Therefore, it would be of interest to assess whether these HPV therapeutic vaccines may confer cross-protection against other high-risk HPV types. Data available from a few clinical trials that enrolled subjects with CINs regardless of the HPV type(s) present demonstrated clinical responses, as measured by CIN regression, in subjects with both vaccine-matched and nonvaccine HPV types. The currently available evidence demonstrating cross-reactivity, epitope spreading, and de novo immune stimulation as possible mechanisms of cross-protection conferred by investigational HPV therapeutic vaccines is discussed.     

Global Proficiency Study of Human Papillomavirus Genotyping

Internationally comparable quality assurance of Human Papillomavirus (HPV) DNA detection and typing methods is essential for evaluation of HPV vaccines and effective monitoring and implementation of HPV vaccination programs. Therefore, the World Health Organization (WHO) HPV Laboratory Network (LabNet) designed an international proficiency study. Following announcement at the WHO website, the responding laboratories performed HPV typing using one or more of their usual assays on 43 coded samples composed of titration series of purified plasmids of 16 HPV types (HPV6, -11, -16, -18, -31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -66, and -68). Detection of at least 50 IU of HPV16 or HPV18 DNA and of 500 genome equivalents (GE) of the other 14 HPV types (in samples with single and multiple HPV types) was considered proficient. Fifty-four laboratories worldwide submitted a total of 84 data sets. More than 21 HPV-genotyping assays were used. Commonly used methods were Linear Array, Lineblot, InnoLiPa, Clinical Array, type-specific real-time PCR, PCR-Luminex and microarray assays. The major oncogenic HPV types (HPV16 and -18) were detected in 89.7% (70/78) and 92.2% (71/77) of the data sets, respectively. HPV types 56, 59, and 68 were the least commonly detected types (in less than 80% of the data sets). Twenty-eight data sets reported multiple false-positive results and were considered nonproficient. In conclusion, we found that international proficiency studies, traceable to international standards, allow standardized quality assurance for different HPV-typing assays and enable the comparison of data generated from different laboratories worldwide.Human papillomavirus (HPV) infection has been established as the major cause of cervical cancer (2). Epidemiological studies have classified genital HPV types into high- and low-risk HPV types, reflecting their association with invasive cancer (19). The most important high-risk types, HPV16 and HPV18, account for about 70% of all invasive cervical cancers worldwide. The next most common HPV types on all continents are HPV31, -33, -35, -45, -52, and -58, found in approximately 20% of cervical cancers (19).An accurate and internationally comparable HPV DNA detection and typing methodology is an essential component in the evaluation of HPV vaccines and in effective implementation and monitoring of HPV vaccination programs. The genotyping assays used today differ in their performance with regard to type-specific detection rates (10). As the methodology for quality assurance and evaluation of assay performance is not standardized, comparisons between different studies that use different assays is particularly difficult (10).The World Health Organization (WHO) establishes international biological standard materials and reference reagents for substances of biological origin used in prophylaxis and in therapy or diagnosis of human diseases (http://www.who.int/biologicals/reference_preparations/en/). At the WHO meeting held in Geneva, Switzerland, from 15 to 17 August 2005, an expert group recommended the establishment of a global HPV laboratory network (HPV LabNet) to contribute to improving the quality of laboratory services for effective surveillance and HPV vaccination impact monitoring. Major activities within the HPV LabNet include the development of international standard reagents and standard operating procedures (SOPs) and the development of internationally comparable quality assurance methods (5, 26).International proficiency panels are already widely used for several microorganisms, including hepatitis A, B, and C viruses; herpes simplex virus (HSV); and human immunodeficiency virus (HIV) (15, 18, 24). As there is no natural source of biological material that could be used to generate type-specific HPV international standards (ISs), the first WHO international collaborative study of the detection of HPV DNA examined the feasibility of using recombinant HPV DNA plasmids as standards, focusing on HPV16 and HPV18 (13). ISs of HPV16 and HPV18 DNA were established for detection and quantification of HPV16 and HPV18 DNA by the WHO Expert Committee on Biological Standardization in 2008 with assigned potency in international units (IU).The international WHO proficiency study described in this report was based on a proficiency panel composed of purified plasmids containing the genomes of 14 oncogenic HPV types and 2 benign HPV types. As the amount of plasmid DNA was titrated in amounts traceable to the IS, the proficiency panel allowed an internationally standardized definition of assay sensitivity. Specificity was defined as an absence of incorrect typing. We also evaluated sample preprocessing with extraction controls of cervical cancer cell lines. The panel was distributed to 61 laboratories worldwide and analyzed using a range of HPV DNA-typing assays in a blinded manner. We report the results in terms of the ability of participating laboratories to correctly identify HPV types, grouped by methods performed, as well as the analytical sensitivity of detecting the HPV types included.     

Comparison of the hybrid capture 2 and cobas 4800 tests for detection of high-risk human papillomavirus in specimens collected in PreservCyt medium

Clinical cervical cytology specimens (n = 466) collected in PreservCyt (Hologic Inc.) were used to evaluate the agreement between Hybrid Capture 2 (hc2; Qiagen) and cobas 4800 (c4800; Roche Molecular Diagnostics) for the detection of high-risk human papillomavirus (HR HPV) genotype infections. The agreement between the two assays was 93.8% (kappa = 0.87; 95% confidence interval, 0.828 to 0.918), with 186 and 251 concordant positive and negative results, respectively. All 186 concordant positives were confirmed using the Linear Array (LA; Roche Molecular Diagnostics) genotyping test. Of the 29 samples with discordant results (6.2%), 18 were hc2 positive and LA verified 17 as positive for HR HPV. Eleven discordant specimens were c4800 positive, and LA confirmed 5 as positive for HR HPV. As of October 2009, practice guidelines in Alberta, Canada, recommend reflex HPV testing for women over 30 years old with atypical squamous cells of undetermined significance (ASCUS) and for women over 50 years old with low-grade squamous intraepithelial lesions (LSIL) to help prioritize those who should undergo further evaluation. In this study, agreement between hc2 and c4800 results for samples from women over 30 years old with ASCUS cytology was 92.3% (n = 13), while no samples from women over 50 years old with LSIL cytology were identified for analysis.