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 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 Abbott RealTime High Risk HPV and Hybrid Capture 2 for the detection of high-risk HPV DNA in a referral population setting

Background

The Abbott RealTime High Risk HPV assay (ART) is an automated multiplex real-time PCR test for detection of DNA from 14 high risk (HR) HPV types in cervical specimens and simultaneous distinction of HPV16 and HPV18 from other HR-HPV.

Objectives

To evaluate the performance of the ART assay in specimens referred for HPV testing to our laboratory (referral population) by comparison with historical data from HC2 and INNO-LiPA as well as histological status, if available.

Study design

412 cervical specimens were collected from women between 18 and 70 years of age: 301 previously tested by HC2 without clinical data and 111 previously tested by HC2 and INNO-LiPA with histological diagnosis of CIN3+.

Results

Our study demonstrated good overall agreement between ART, HC2 and INNO-LiPA. In the group of the CIN3+ specimens HR-HPV was detected by ART in 93.07% (95% CI: 88.12-98.02), while HR-HPV detection rates with HC2 and INNO-LiPA were 91.09% (95% CI: 85.53-96.65) and 95.05% (95% CI: 90.82-99.28), respectively. The typing capability of ART for HPV16, HPV18 and a pool of twelve other HR-HPV types was investigated by comparison with INNO-LiPA demonstrating high overall assay concordance (89.81%; k 0.87).

Conclusions

The Abbott RealTime assay showed similar clinical performance for detection of CIN3+ compared with HC2. The high level of automation and ability to identify HPV16, HPV18 and other HR-HPV make this assay a very attractive option for HR-HPV testing, potentially improving patient management by risk stratification of cytological abnormal populations.     

Detection of HPV DNA in cervical carcinomas by PCR and hybrid capture assay

HPV DNA was detected in exfoliated cervical cells of 73% (85/116) cervical cancer patients by PCR using HPV consensus primers and by hybrid capture assay (HC II) (Digene Corp., USA) in 77 of the 85 cases found HPV positive by PCR. Presence of HPV 16/18 DNA were investigated in the 79 cases by PCR using type specific primers. HPV 16 was detected in 31 (39%) patients, HPV 18 in 7 (8.8%), both HPV 16 and 18 in 19 (24%) and HPVs other than 16/18 in 22 (27.8%) cases. Age and clinical stages had no significant effect on HPV prevalence. Double infection of HPV 16 and 18 was significantly (p<0.05) high in the older patients (56 years or more) compared to younger group. Results indicated that cervical cancers in India are strongly associated with high-risk type HPV infection. HC II assays and PCR results for detection of HPV in cervical smears were comparable.     

Clinical Validation of the Cervista HPV HR Test According to the International Guidelines for Human Papillomavirus Test Requirements for Cervical Cancer Screening

This study demonstrates that both the clinical sensitivity and specificity of the Cervista HPV HR test for high-risk human papillomavirus (HPV) detection are not inferior to those of the Hybrid Capture 2 (HC2) test. The intra- and interlaboratory reproducibilities of Cervista were 92.0% (kappa, 0.83) and 90.4% (kappa, 0.80), respectively. The Cervista HPV HR test fulfills all the international HPV test requirements for cervical primary screening purposes.     

Comparison of the Cobas 4800 Human Papillomavirus test against a combination of the Amplicor Human Papillomavirus and the Linear Array tests for detection of HPV types 16 and 18 in cervical samples

The greater prevalence of human papillomavirus (HPV) types 16 and 18 compared to the other high-risk HPV types of cervical cancer led to the development of clinical tests that detect both types separately from other genotypes. One method is the Roche Cobas 4800 HPV test, which is based on a real-time PCR. The aim of this study was to evaluate the performance of the Cobas 4800 HPV test for detecting genotypes 16 and 18 by comparing the results with those obtained in a combination of the Roche Amplicor HPV assay and the Roche Linear Array (LA) HPV genotyping assay. Excellent concordance was found between both methods (92.7%, kappa value=0.872). The Cobas 4800 HPV test could be used as a single test for identifying HPV types 16 and 18 directly from clinical specimens.     

Digene HPV Genotyping RH Test RUO: Comparative evaluation with INNO-LiPA HPV Genotyping Extra Test for detection of 18 high-risk and probable high-risk human papillomavirus genotypes

BackgroundStandardized and validated methods for the specific detection and identification of a spectrum of high-risk (hr) HPV genotypes will be necessary if HPV genotyping gains an important role in the clinical management of HPV-related precancerous lesions and cancers.ObjectivesThe first comparative evaluation of novel HPV genotyping Digene HPV Genotyping RH Test RUO (Qiagen, Hilden, Germany) with standard INNO-LiPA HPV Genotyping Extra CE assay (Innogenetics, Gent, Belgium).Study designSeventy hr-HPV positive samples were tested in parallel with both genotyping assays. The results were interpreted taking into account 15 hr-HPV and 3 probable hr-HPV genotypes that can be identified by both assays (assay-common genotypes).ResultsConcordant results (a complete match of assay-common genotypes or negative using both assays) and compatible results (at least one genotype in common) were obtained in 42 (60.0%) and 28 (40.0%) samples, respectively. No discordant results for assay-common genotypes were obtained. Of 42 samples with compatible results, the presence of at least one assay-common genotype was detected in 37 samples, while no HPV was detected in two samples by both assays and only a single low-risk HPV was detected by INNO-LiPA in three samples.ConclusionsA novel Digene test is suitable for the detection of hr-HPV genotypes in clinical samples and it provides comparable results to the well established INNO-LiPA assay. Although INNO-LiPA identified significantly more samples with multiple HPV genotypes than the Digene test, the clinical benefit of such a difference is at present unclear.     

Comparison of the Digene Hybrid Capture 2 assay and Roche AMPLICOR and LINEAR ARRAY human papillomavirus (HPV) tests in detecting high-risk HPV genotypes in specimens from women with previous abnormal Pap smear results

The development of cervical cancer is strongly associated with the presence of persistent high-risk (HR) human papillomavirus (HPV) infection. Recently, the commercially manufactured PCR-based Roche AMPLICOR (AMP) and LINEAR ARRAY (LA) HPV tests have become available for HPV detection. However, knowledge of their clinical performance compared to the U.S. Food and Drug Administration-approved Hybrid Capture 2 (HC2) assay is limited. This study evaluated the concordance between the HC2, AMP, and LA tests in detecting HR-HPV among a cohort of 1,679 women with previous abnormal Pap smear results. Overall, 1,393 specimens (81.3%) generated concordant results for HR-HPV presence or absence by the three assays. The concordance levels were substantial between the HC2 and AMP tests (84.4%, kappa = 0.6419) and between the HC2 and LA tests (84.0%, kappa = 0.6341) and nearly perfect between the AMP and LA tests (97.8%, kappa = 0.9441). HR-HPV prevalence, as detected by the AMP or LA tests, was significantly higher among women with cytological or histological high-grade disease (CIN2 or greater) than that detected by HC2 (P < 0.0001). The AMP and LA tests exhibited greater sensitivity, but lower specificity, than HC2 for detecting HR-HPV among this cohort of women with underlying cervical abnormalities, particularly among subjects with histologically proven high-grade disease. Both PCR-based HPV tests may be valuable in the management of care for women with underlying cervical abnormalities, in predicting treatment success, and in studying the clearance or acquisition of new infections.     

HPV typing of cervical squamous lesions by in situ HPV DNA hybridization: Influence of HPV type and therapy on the follow-up of low-grade squamous cervical disease

Papanicolaou (Pap)-stained cervical specimens from 160 squamous lesions were processed for the detection of human papillomavirus (HPV) DNA by an in situ hybridization (ISH) assay. Three biotinylated HPV DNA probes were employed, each containing HPV genotypes 6/11, HPV genotypes 16/18, or HPV genotypes 31/35/51. The HPV etiology of 86 lesions was ascertained (53.8%). In 74 out of 135 (58.8%) HPV-typed low-grade squamous intraepithelial lesions (SILs), HPV 6/11 was found in nine (6.6%), HPV 16/18 in 46 (34.2%), and HPV31/35/51 in 19 lesions (14.1%); in 11 out of 18 HPV-typed high-grade SILs (61.1%), seven lesions (38.9%) were typed for HPV 16/18 and four (22.2%) for HPV 31/35/51. Of seven invasive carcinomas, only one (14.3%) reacted with the HPV 16/18 DNA probe. A cohort of 124 low-grade SILs was followed cytologically for a year. The results of this study are discussed in light of HPV type association and therapy. Diagn Cytopathol 1994; 11:28–32. © 1994 Wiley-Liss, Inc.     

Comparison of Onclarity Human Papillomavirus (HPV) Assay with Hybrid Capture II HPV DNA Assay for Detection of Cervical Intraepithelial Neoplasia Grade 2 and 3 Lesions

Analytical and clinical performance validation is essential before introduction of a new human papillomavirus (HPV) assay into clinical practice. This study compares the new BD Onclarity HPV assay, which detects E6/E7 DNA from 14 high-risk HPV types, to the Hybrid Capture II (HC2) HPV DNA test, to concurrent cytology and histology results, in order to evaluate its performance in detecting high-grade cervical lesions. A population of 567 women, including 325 with ≥ASCUS (where ASCUS stands for atypical cells of undetermined significance) and any HC2 result and 242 with both negative cytology and negative HC2 results, were prospectively enrolled for the study. The overall agreement between Onclarity and HC2 was 94.6% (95% confidence intervals [CI], 92.3% to 96.2%). In this population with a high prevalence of disease, the relative sensitivities (versus adjudicated cervical intraepithelial neoplasia grades 2 and 3 [CIN2+] histology endpoints) of the Onclarity and HC2 tests were 95.2% (95% CI, 90.7% to 97.5%) and 96.9% (95% CI, 92.9% to 98.7%), respectively, and the relative specificities were 50.3% (95% CI, 43.2% to 57.4%) for BD and 40.8% (95% CI, 33.9%, 48.1%) for HC2. These results indicate that the BD Onclarity HPV assay has sensitivity comparable to that of the HC2 assay, with a trend to an increased specificity. Moreover, as Onclarity gives the chance to discriminate between the different genotypes, we calculated the genotype prevalence and the absolute risk of CIN2+: HPV 16 was the most prevalent genotype (19.8%) with an absolute risk of CIN2+ of 77.1%.     

Prevalence of HPV genotypes determined by PCR and DNA sequencing in cervical specimens from French women with or without abnormalities

BACKGROUND: Epidemiological data on human papillomavirus (HPV) are needed to estimate potential changes in type distribution induced by recent HPV vaccination strategies. OBJECTIVES AND STUDY DESIGN: The epidemiological distribution of HPV in 669 cervical specimens from French women with and without cytological abnormalities was evaluated using type-specific PCR or sequencing. The results were compared with those obtained using the Digene high-risk Hybrid Capture 2 (HR-HC2) assay. RESULTS: The overall prevalence of HPV was high (45.3%) in our study population. 285 of the 291 HPV-positive samples were typed. The distribution frequency concerned 34 different genotypes, with HPV16 being the most prevalent (32.6%). Other genotypes present were HPV31 (7.4%), HPV18, HPV 52 (both 6.0%), HPV6 (5.3%) and HPV66 (4.2%). The respective frequencies of all other genotypes were below 4%. The agreement with HR-HC2 was 78.8%. The distribution frequency data were also analyzed relatively to cytological and histological results. Our method enables the diagnosis of HPV infections with the additional advantage of genotyping. CONCLUSION: HPV infections in the area of France studied here involve numerous HPV types, but the high cumulative prevalences of types 16, 18, 6 and 11 (44.6% in total) would suggest a major impact of vaccination on these genotypes.     

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.     

Comparison of the Digene HC2 assay and the Roche AMPLICOR human papillomavirus (HPV) test for detection of high-risk HPV genotypes in cervical samples

Many different methods with different sensitivity and specificity have been proposed to detect the presence of high-risk human papillomavirus (HR HPV) in cervical samples. The HC2 is one of the most widely used. Recently, a new standardized PCR-based method, the AMPLICOR HPV test, has been introduced. Both assays recognize the same 13 HR HPV genotypes. The performances of these two commercially available assays were compared in 167 consecutive women (for a total of 168 samples) who presented at the Colposcopy Clinic either for a follow-up or for a diagnostic visit. Concordant results were found in 140/168 cervical samples (overall agreement, 83%; Cohen's kappa = 0.63). Twenty-eight samples gave discordant results: 20 were positive with the AMPLICOR HPV test and negative with the HC2 assay, and 8 were negative with the AMPLICOR HPV test and positive with the HC2 assay. The genotyping showed that no HR HPV was detected in the 8 HC2 assay-positive AMPLICOR HPV test-negative samples, while in 8/20 AMPLICOR HPV test-positive HC2 assay-negative samples, an HR HPV genotype was found. The AMPLICOR HPV test scored positive in a significantly higher percentage of subjects with normal Pap smears. All 7 cervical intraepithelial neoplasia grade 3 patients scored positive with the AMPLICOR HPV test, while 2 of them scored negative with HC2. Both tests had positive results in the only patient with squamous cell carcinoma. In conclusion, this study shows that the HC2 assay and the AMPLICOR HPV test give comparable results, with both being suitable for routine use. The differences noted in some cases may suggest a different optimal clinical use.     

Clinical performance of Abbott RealTime High Risk HPV test for detection of high-grade cervical intraepithelial neoplasia in women with abnormal cytology

BackgroundAbbott RealTime High Risk (HR) HPV is a recently developed test for the detection of 14 high-risk oncogenic HPV types combined with the ability to concurrently identify genotypes 16 and 18.ObjectivesThe clinical performance of the Abbott RealTime HR HPV test was evaluated in comparison with the Hybrid Capture 2 (HC2) test for the detection of cervical intraepithelial neoplasia 2 or worse (CIN2+). The relative accuracy of the Abbott RealTime HR HPV to detect high-risk HPV was also determined.Study designCervical specimens were collected from 702 patients with abnormal cytology who were referred for colposcopy, and were tested with liquid based cytology (LBC), Abbott RealTime HR HPV and HC2. Genotyping was done using the Linear Array (LA) method. Histological assessment was used as the gold standard for disease status. Clinical performance for detection of disease was evaluated for Abbott RealTime HR HPV in comparison with HC2 in the overall population and in each cytological grade. The relative accuracy for detection of high-risk HPV was assessed by concordance between the two tests and based on LA genotyping.Results and ConclusionsThe Abbott RealTime HR HPV showed similar clinical performance for detection of CIN2+ when compared with HC2, for both the overall population and those with a cytological grade of atypical squamous cells of undetermined significance (ASC-US). The accuracy for detection of high-risk HPV was significantly higher with Abbott RealTime HR HPV than with HC2.     

Comparison of the performance of different HPV genotyping methods for detecting genital HPV types

Classification of high-risk HPV types for cervical cancer screening depends on epidemiological studies defining HPV type-specific risk. The genotyping tests that are used, are however, not uniform with regard to type-specific detection rates making comparisons between different studies difficult. To overcome the lack of a "gold standard" four tests were evaluated crosswise using 824 cervical smears pretested by HC2. The tests evaluated were the L1-PCR-based assays PGMY09/11 LBA, HPV DNA Chip and SPF LiPA and an E1 consensus PCR followed by cycle sequencing (E1-PCR). A subset of 265 samples was tested in addition with the GP5+/6+ reverse line blot assay. Differences were noted in the sensitivity and range for specific HPV types, e.g. with detection rates for HPV53 ranging from 2.3% to 11.6%. HPV16 was the most prevalent type detected by all tests except for the SPF-10 LiPa, which detected HPV31 more often. Kappa values calculated ranged from poor (k=0.20) to intermediate (k=0.54) for HPV positivity, but were higher for high-risk type positivity (k=0.31-0.61) and best for recognition of HPV16 (k=0.53-0.72). The analytical sensitivity of the tests ranged between 15% and 97% for individual types and specificity was highly dependent on which test system was used as "gold standard" for the analysis. The results of histology were used for calculation of clinical sensitivity and specificity. E1-PCR, PGMY09/11 LBA and SPF-10 LiPA had a high clinical sensitivity (>95%) for the detection of cervical intraepithelial neoplasia 2 or higher, whereas the HPV DNA Chip reached only 84.1%.     

High HPV genetic diversity in women infected with HIV-1 in Brazil

The present study on genetic diversity of human papillomaviruses in women infected by HIV in Brazil describes the frequency, the genotypes, and five new variants of HPV. One hundred fifty cervical smears of HIV-positive women were subjected to cytological examination, and the DNA samples obtained were assayed by MY09/MY11 amplification, followed by RFLP typing. The overall HPV-DNA-positive rate was 42.7%. One hundred twenty-two samples (81.3%) had benign cellular alterations or normal cytological results, and HPV DNA frequency among them was 30.3%. Otherwise, 96.4% of samples with altered cytology were positive for HPV DNA. A high diversity of genotypes was observed. HPVs-16 and 81 were the most prevalent (14.1%) and were followed by HPVs 52, 35, 62, 33, 53, 56, 66, 70, 18, 58, 6b, 11, 31, 39, 40, 61, 71, 32, 54, 59, 67, 68, 85, and 102. Five new variants of the high-risk HPVs 18, 33, 53, 59, and 66 were detected. Possible associations between the detection of HPV genotypes and the cytological classification, HIV viral load, CD4 count, and antiretroviral treatment were also examined. We observed that a high proportion of HIV-infected women are infected with HPV and may carry oncogenic genotypes, even when cytological evaluation shows normal results.     

Human papillomavirus testing with the hybrid capture 2 assay and PCR as screening tools

The recognition of high-risk human papillomaviruses (HPVs) as etiological agents of cervical cancer has increased the demands to use testing for HPV for the detection of abnormal cervical smears and for cervical cancer screening. The present study compared the performance of the Hybrid Capture 2 (HC2) assay with that of PCR for the detection of significant cervical lesions in 1,511 women with different risks for HPV infections in three New Independent States of the former Soviet Union. The results showed that the level of agreement between the HC2 assay and PCR was substantial, with a kappa (Cohen) value of 0.669 (95% confidence interval [CI], 0.629 to 0.709). Of the 228 samples with discrepant results, 92 were positive by the HC2 assay but negative by PCR, whereas 136 samples were PCR positive but HC2 assay negative. The positive predictive values (PPVs) of the HC2 assay and PCR in detecting high-grade intraepithelial lesions (HSILs) were 4.5% (95% CI, 3.5 to 5.5%) and 3.6% (95% CI, 2.7 to 4.5%), respectively, and the negative predictive values (NPVs) were 99.6% (95% CI, 99.3 to 99.9%) and 99.3% (95% CI, 98.9 to 99.7%), respectively. The sensitivities of the HC2 assay and PCR for the detection of HSILs were 85.2 and 74.0%, respectively, and the specificities were 67.2 and 64.1%, respectively. In receiver operating characteristic (ROC) analysis, the performance of the HC2 assay for the detection of HSILs was excellent (P = 0.0001); the area under the ROC analysis curve was 0.858 (95% CI, 0.811 to 0.905), and the optimal balance between sensitivity (86.5%) and specificity (80%) was obtained with an HC2 assay cutoff level of 15.6 relative light units/positive control. Use of this cutoff would increase the specificity of the HC2 assay to 80.0% without compromising sensitivity. In conclusion, the results of PCR and the HC2 assay were concordant for 85% of samples, resulting in substantial reproducibility. Both tests had low PPVs, equal specificities, and equal (almost 100%) NPVs for the detection of HSILs; but the sensitivity of the HC2 assay was slightly better.     

Comparison of the Anyplex II HPV28 assay with the Hybrid Capture 2 assay for the detection of HPV infection

BackgroundHuman papillomavirus (HPV) testing is an important part of cervical cancer screening and management of women with abnormal cytology results. The Hybrid Capture 2 (HC2) has been recommended for use as a reference test.ObjectiveTo evaluate a new real-time PCR assay (Anyplex II HPV28) for detecting high risk (HR) HPV and to compare it to the HC2. In addition, we compared the genotyping results of the Anyplex II HPV28 to those of sequencing analysis.Study designA total of 1114 cervical swab specimens were consecutively obtained from a single healthcare center. We submitted all specimens for HPV detection with Anyplex II HPV28 and HC2, then analyzed the discordant results using multiplex PCR followed by direct sequencing.ResultsHC2 detected 72 (6.5%) cases with HR HPV, while Anyplex II HPV28 identified 138 (12.4%) cases. The overall agreement rate was 91.4% (1018/1114) of cases. Discordant results between these two assays were observed in 96 cases; 15 were positive only by HC2, and 81 were positive only by Anyplex II HPV28. Sequencing analyses performed in 80 cases of discordant results revealed 11 false-positive, and 67 false-negative results using HC2 tests and two false-positive results using Anyplex II HPV28.ConclusionsThe Anyplex II HPV28 assay is analytically more sensitive in the detection of the 13 HR types represented by the HC2 assay and exhibited a higher concordance with comprehensive genotyping based on the sequencing analysis, and it could be used as a laboratory testing method for identifying HPV genotypes.     

Neutralization of HPV16, 18, 31, and 58 pseudovirions with antisera induced by immunizing rabbits with synthetic peptides representing segments of the HPV16 minor capsid protein L2 surface region

Neutralizing antibody against human papillomavirus (HPV) minor capsid protein L2 can cross-neutralize different HPV genotypes in vitro. To identify the segments containing the cross-neutralization epitopes of HPV16 L2, we characterized antisera obtained by immunizing two rabbits with each of the ten synthetic peptides of 14 to 20 amino acids (aa) long, which represents a part of the HPV16 L2 sequence from aa 14 to 144. The antisera against the peptides within the region from aa 18 to 144 efficiently bound to HPV16 L1/L2-capsids and neutralized HPV16 pseudovirions, indicating that the region is displayed on the surface of the capsids and contains several neutralization epitopes. Antiserum against the peptide from aa 18 to 38 (anti-P18/38) cross-neutralized HPV18. Anti-P56/75 cross-neutralized HPV18, 31, and 58. Anti-P61/75 and anti-P64/81 cross-neutralized HPV18 and 58. Anti-P96/115 and the antiserum induced by a mutant P96/115 (S and T at aa 101 and 112 were replaced with L and S, respectively) cross-neutralized HPV31 and 58. The mixture of equal volumes of three antisera, anti-P18/38, anti-P56/75, and anti-mutant P96/115, neutralized HPV16, 18, 31, and 58 more efficiently than anti-P56/75 alone, suggesting that there is a synergistic effect of antibodies on the cross-neutralization. The cross-neutralization appears to be correlated with conserved aa sequences among HPV types. The data in this study provide a basis for designing vaccine antigens effective against a broader spectrum of the high-risk HPVs.