International proficiency study of a consensus L1 PCR assay for the detection and typing of human papillomavirus DNA: evaluation of accuracy and intralaboratory and interlaboratory agreement

The PGMY L1 consensus primer pair combined with the line blot assay allows the detection of 27 genital human papillomavirus (HPV) genotypes. We conducted an intralaboratory and interlaboratory agreement study to assess the accuracy and reproducibility of PCR for HPV DNA detection and typing using the PGMY primers and typing amplicons with the line blot (PGMY-LB) assay. A test panel of 109 samples consisting of 29 HPV-negative (10 buffer controls and 19 genital samples) and 80 HPV-positive samples (60 genital samples and 20 controls with small or large amounts of HPV DNA plasmids) were tested blindly in triplicate by three laboratories. Intralaboratory agreement ranged from 86 to 98% for HPV DNA detection. PGMY-LB assay results for samples with a low copy number of HPV DNA were less reproducible. The rate of intralaboratory agreement excluding negative results for HPV typing ranged from 78 to 96%. Interlaboratory reliability for HPV DNA positivity and HPV typing was very good, with levels of agreement of >95% and kappa values of >0.87. Again, low-copy-number samples were more prone to generating discrepant results. The accuracy varied from 91 to 100% for HPV DNA positivity and from 90 to 100% for HPV typing. HPV testing can thus be accomplished reliably with PCR by using a standardized written protocol and quality-controlled reagents. The use of validated HPV DNA detection and typing assays demonstrating excellent interlaboratory agreement will allow investigators to better compare results between epidemiological studies.     

Consensus polymerase chain reaction and enzyme-linked immunosorbent assay for human papillomavirus detection and typing in cervical specimens.

Human papillomavirus (HPV) infection is common in cervical intraepithelial neoplasia (CIN). This study investigates HPV detection and typing assay based on polymerase chain reaction amplification of L1 open reading frame with general primers GP5/GP6, followed by enzyme-linked immunosorbent assay detection with type-specific DNA probes. To determine the sensitivity of this assay, formalin-fixed CaSki cells were used as reference cell lines. Fifty copies of viral DNA diluted in DNA from 100,000 noninfected cells could be detected. This assay was also investigated for HPV detection and typing of 67 cervical specimens diagnosed with with CIN III or carcinoma in situ (CIS) and their adjacent squamous epithelium. The CIN III lesions were infected in approximately 80% of the samples, 81% in the neighboring CIN II, and 68% in CIN I. The HPV infection was even detectable in 54% of nondysplastic epithelium located near a CIN III lesion.     

Comparisons of HPV DNA detection by MY09/11 PCR methods

Two modifications to the original L1 consensus primer human papillomavirus (HPV) PCR method, MY09-MY011, using AmpliTaq DNA polymerase (MY-Taq), were evaluated for HPV DNA detection on clinical specimens from a cohort study of cervical cancer in Costa Rica. First, HPV DNA testing of 2978 clinical specimens by MY09-MY011 primer set, using AmpliTaq Gold DNA polymerase (MY-Gold) were compared with MY-Taq testing. There was 86.8% total agreement (kappa = 0.72, 95%CI = 0.70-75) and 69.6% agreement among positives between MY-Gold and MY-Taq. MY-Gold detected 38% more HPV infections (P < 0.0001) and 45% more cancer-associated (high-risk) HPV types (P < 0.0001) than MY-Taq, including 12 of the 13 high-risk HPV types. Analyses of discordant results using cytologic diagnoses and detection of HPV DNA by the Hybrid Capture 2 Test suggested that MY-Gold preferentially detected DNA positive specimens with lower HPV viral loads compared with MY-Taq. In a separate analysis, PGMY09-PGMY11 (PGMY-Gold), a redesigned MY09/11 primer set, was compared with MY-Gold for HPV DNA detection (n = 439). There was very good agreement between the two methods (kappa = 0.83; 95%CI = 0.77-0.88) and surprisingly no significant differences in HPV detection (P = 0.41). In conclusion, we found MY-Gold to be a more sensitive assay for the detection of HPV DNA than MY-Taq. Our data also suggest that studies reporting HPV DNA detection by PCR need to report the type of polymerase used, as well as other assay specifics, and underscore the need for worldwide standards of testing.     

Development of a sensitive and specific assay combining multiplex PCR and DNA microarray primer extension to detect high-risk mucosal human papillomavirus types

The importance of assays for the detection and typing of human papillomaviruses (HPVs) in clinical and epidemiological studies has been well demonstrated. Several accurate methods for HPV detection and typing have been developed. However, comparative studies showed that several assays have different sensitivities for the detection of specific HPV types, particularly in the case of multiple infections. Here, we describe a novel one-shot method for the detection and typing of 19 mucosal high-risk (HR) HPV types (types 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 70, 73, and 82). This assay combines two different techniques: multiplex PCR with HPV type-specific primers for amplification of viral DNA and array primer extension (APEX) for typing. This novel method has been validated with artificial mixtures of HPV DNAs and clinical samples that were already analyzed for the presence of mucosal HPV types by a different consensus PCR method, i.e., GP5+/GP6+. Our data showed a very good agreement between the results from the multiplex PCR/APEX assay and those from the GP5+/GP6+ PCR (overall rates of HPV positivity, 63.0 and 60.9%, respectively). Whereas the GP5+/GP6+ PCR was slightly more sensitive for the detection of HPV type 16 (HPV-16), multiplex PCR-APEX found a higher number of infections with HPV-33, HPV-53, and multiple HPV types. These favorable features and the high-throughput potential make our present novel assay ideal for large-scale clinical and epidemiological studies aimed at determining the spectrum of mucosal HR HPV types in cervical specimens.     

Human papillomavirus genotyping by 454 next generation sequencing technology

Background

An accurate tool for human papillomavirus (HPV) typing is important both for management of patients with HPV infection and for surveillance studies.

Objectives

Design and evaluation of an HPV typing method based on 454 next generation sequencing (NGS) technology.

Study design

Development of an HPV typing method based on 454 NGS of HPV L1 amplicons generated with MY09/11-based primers. Evaluation of the NGS method in control samples and in a panel of cervical cytological samples. Comparison of the NGS typing method with cycle sequencing and with the reverse hybridization-based INNO-LiPA HPV Genotyping Extra assay (LiPA).

Results

In control samples carrying mixtures of HPV16 and HPV18 DNA, the NGS method could reliably detect genotype sequences occurring at a frequency of 1% in multiple infections with a sensitivity of 100 genome equivalents/μL. In cervical cytology samples, comparison with cycle sequencing demonstrated accuracy of HPV typing by NGS. The NGS method had however lower sensitivity for some HPV types than LiPA, conceivably due to the poor sensitivity of the MY09/11-based primers. At variance, LiPA could not detect HPV types which were present in low proportion in multiple infections (<10% of HPV reads obtained by NGS). In addition, NGS allowed identifying the presence of different variants of the same HPV type in a specimen.

Conclusions

NGS is a promising method for HPV typing because of its high sensitivity in multiple infection and its potential ability to detect a broad spectrum of HPV types, subtypes, and variants.     

Development of a general-primer-PCR-reverse-line-blotting system for detection of beta and gamma cutaneous human papillomaviruses

The beta and gamma genera of papillomaviruses consist of epidermodysplasia verruciformis-related human papillomaviruses (HPVs) and phylogenetically related cutaneous HPVs. Here, we have developed a consensus primer PCR assay and reverse line blot typing system coupled thereto (referred to as beta and gamma cutaneous HPV PCR [BGC-PCR]) for detection and typing of 24 beta and gamma HPVs (HPV types 4, 5, 8, 9, 12, 14, 15, 17, 19, 20, 21, 22, 23, 24, 25, 36, 37, 38, 47, 48, 49, 50, 60, and 65). Because the HPV-specific PCR products are only 72 bp in size, the system is suitable for formalin-fixed, paraffin-embedded specimens and other samples in which the DNA is of suboptimal quality. This system was able to detect and type as little as 100 ag to 1 fg HPV DNA per reaction (depending on the HPV type) in a background of 100 ng human DNA without any cross-reactivity between the tested types. Beta and gamma HPVs were detected in DNA extracted from plucked eyebrow hairs of 31 of 34 renal transplant recipients. In addition, formalin-fixed, paraffin-embedded specimens from nonmelanoma skin tumors of renal transplant recipients (n = 25) and immunocompetent individuals (n = 15) scored BGC-PCR positive in 21 and 6 cases, respectively, with HPV type 5 (HPV5) and HPV8 being the predominant types. The data indicate that this method can be a valuable, user-friendly tool for the detection and typing of cutaneous HPV in clinical specimens and may have implications for future monitoring of vaccines or alternative treatment modalities for diseases caused by these cutaneous HPVs.     

Accurate human papillomavirus genotyping by 454 pyrosequencing

Accurate HPV typing is essential for evaluation and monitoring of HPV vaccines, for second-line testing in cervical cancer screening, and in epidemiological surveys. In this study, we set up and assessed in clinical samples a new HPV typing method based on 454 next-generation sequencing (NGS) of HPV L1 amplicons, generated by using a modified PGMY primer set with improved sensitivity for some HPV types that are not targeted by standard PGMY primers. By using a median 12 800-fold coverage, the NGS method allowed us to correctly identify all high-risk HPV types, in either single or multiple infections, with a sensitivity of 50 genome equivalents, as demonstrated by testing WHO LabNet EQA sample panels. Analysis of mixtures of HPV16- and HPV18-positive cell lines demonstrated that the NGS method could reproducibly quantify the proportion of each HPV type in multiple infections in a wide dynamic range. Testing of HPV-positive clinical samples showed that NGS could correctly identify a high number of HPV types in multiple infections. The NGS method was also effective in the analysis of a set of cervical specimens with discordant results at hybrid capture 2 and line probe assays. In conclusion, a new HPV typing method based on 454 pyrosequencing was set up. This method was sensitive, specific, quantitative and precise in both single and multiple infections. It could identify a wide range of HPV types and might potentially discover new HPV types.     

Complete genotyping of mucosal human papillomavirus using a restriction fragment length polymorphism analysis and an original typing algorithm.

BACKGROUND: Due to the differences in the oncogenic activity of human papillomaviruses (HPV), it is clinically important to accurately identify HPV types in a simple and time effective manner. OBJECTIVES: We aimed at developing a straightforward and cost-effective assay to individually identify all mucosal HPVs, based on the amplification of L1 gene using MY09/11 primers, and subsequent restriction fragment length polymorphism (RFLP) analysis. STUDY DESIGN: We made use of bioinformatic tools to analyze all published DNA sequences of 49 mucosal HPV types for PstI, HaeIII, DdeI and RsaI restriction sites. Based on the RFLP patterns, we have designed an original genotyping algorithm. RESULTS: Each HPV type presented a distinct RFLP pattern, which was visually distinguishable on polyacrylamide gels. A set of 27 pre-selected patient samples of known HPV types was confirmed positive for the same HPV type using this RFLP assay. Furthermore, in a random and blind HPV typing experiment performed in 30 untyped clinical samples, RFLP data consistently matched DNA sequencing results. CONCLUSIONS: Our polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, using 4 restriction enzymes (PstI, HaeIII, DdeI, RsaI) and an original genotyping algorithm, allows discrimination of all individual mucosal HPV types in single infections, and even detection of multiple infections. This assay gives complementary information to commercially available methods, and may also be financially advantageous, particularly when financial resources are scarce.     

Comparison of the Abbott RealTime High Risk HPV with Genomica HPV Clinical Array for the detection of human papillomavirus DNA

Human papillomavirus (HPV) has been identified as the major cause of cervical cancer worldwide and HPV DNA testing is recommended in primary cervical cancer screening. Several molecular tests for detection/typing of HPV DNA with different sensitivity and specificity are commercially available. The present study compared the performance of the Abbott RealTime High Risk HPV assay and the Genomica HPV Clinical Array CLART2 in 78 specimens (63 cervical smears and 15 rectal/urethral swabs).The typing results of the Genomica assay were in absolute agreement with each of the four possible result categories of the Abbott assay (HPV16, HPV18, Other HR HPV, not detected) in 87.2% (68/78) of the samples, with a Cohen' kappa agreement coefficient for every HR type of 0.62 (95% CI: 0.39–0.85), higher in cervical swabs (k = 0.74, 95% CI: 0.50–0.99) than in rectal/urethral swabs (k = 0.36, 95% CI: 0.00–0.82). There was an excellent agreement of the Genomica results with those of Abbott in cervical samples harbored HPV single infection (100% agreement). Nonetheless, both methods may lose sensitivity for detecting HPV types in multiple infections, giving discordant results (10/78). This underlines the importance of establishing the analytical sensitivity in HPV type detection in single and multiple HPV infections. In rectal/urethral swabs, 5 of 15 (33%) discordant cases were observed, most of which became compatible when the Genomica assay was performed starting from nucleic acid extracted with the Abbott m2000sp system. These results suggest that nucleic extraction based on the magnetic beads technique is suitable for HPV DNA detection in urethral/rectal swabs.     

Rapid detection and typing of herpes simplex virus DNA in clinical specimens by the hybrid capture II signal amplification probe test.

A second-generation signal amplification, nucleic acid-based test for the rapid detection and typing of herpes simplex virus (HSV) DNA was developed and evaluated with artificial and clinical specimens. The analytical sensitivity of the Hybrid Capture II (HC II) HSV DNA assay was determined by testing either cloned HSV DNA or total genomic HSV DNA titrations and resulted in detection thresholds of between 5 x 10(3) and 1 x 10(4) copies per assay. Specificity was assessed by testing a panel of bacteria and viruses commonly found in the female genital tract. Sensitivity was assessed by testing 112 ulcerative genital lesions by the HC II assay and comparing the results to those obtained by routine cell culture. Discrepant results were resolved by PCR testing. After resolution of the discrepant results, the sensitivity of the HC II assay compared to the consensus result (the results of two of three tests, the HC II assay, culture, and PCR, were in agreement) was 93.2% (41 of 44 specimens), and the specificity was 100% (60 of 60 specimens). Culture gave a sensitivity of 84.1% (37 of 44 specimens) and a specificity of 100% (60 of 60 specimens) compared to the consensus result. The results of HSV typing by the HC II assay and culture agreed in all cases. The HC II assay is a rapid and accurate assay for detecting and typing HSV types 1 and 2, with a sensitivity comparable to that of culture and greater ease of use than culture.     

Denaturing high-performance liquid chromatography for detecting and typing genital human papillomavirus

Human papillomaviruses (HPVs) are important in the development of human cancers, including cervical and oral tumors. However, most existing methods for HPV typing cannot routinely distinguish among the more than 100 distinct types of HPV or the natural HPV intratypic variants that have also been documented. To address this problem, we developed a novel method, general primer-denaturing high-performance liquid chromatography (GP-dHPLC), for the detection and typing of genital HPV using an automated 96-well plate format. GP-dHPLC uses general primer PCR (GP-PCR) to amplify the viral DNA and then analyzes the GP-PCR products by denaturing high-performance liquid chromatography (dHPLC). A number of different primer pairs with homology to most known genital HPV types were tested, and the L1C1-L1C2M pair specific for the L1 region of the viral genome was chosen. A set of HPV standard control patterns, consisting of those for HPV types 16, 18, 31, 33, 39, 45, 51, 52, 56, 58, 59, 6, and 11, was established for genital HPV typing. One hundred eighty-six frozen and formalin-fixed cervical cancer tissue samples were analyzed for the presence of HPV and the HPV type by this method, and 95.8% of them were found to contain HPV DNA. GP-dHPLC accurately discriminated among HPV variants that differed by as little as one nucleotide. Several new variants of HPV types 16, 18, 39, 45, 52, and 59 were identified. Moreover, multiple HPV infections were detected in 26.6% of the samples. Our results indicate that HPV typing by GP-dHPLC permits discrimination of common genital HPV types, detection of multiple HPV infections, and identification of HPV variants in clinical samples.     

Development and clinical evaluation of a highly sensitive DNA microarray for detection and genotyping of human papillomaviruses

Human papillomavirus (HPV) has been found in cervical cancer, tonsillar cancer, and certain types of head and neck cancers. We report on a DNA microarray-based method for the simultaneous detection and typing of HPVs. The genotype spectrum discriminated by this HPV DNA microarray includes 15 high-risk HPV genotypes and 12 low-risk HPV genotypes. The HPV DNA microarray showed high degrees of specificity and reproducibility. We evaluated the performance of the HPV DNA microarray by application to three HPV-positive cell lines (HeLa, Caski, and SiHa cells) and two HPV-negative cell lines (C33A and A549 cells). The HPV DNA microarray successfully identified the known types of HPV present in the cell lines. The detection limit of the HPV DNA microarray was at least 100-fold higher than that of PCR. To assess the clinical applicability of the HPV DNA microarray, we performed the HPV genotyping assay with 73 nonmalignant and malignant samples from 39 tonsillar cancer patients. Twenty-five of the 39 (64.1%) malignant samples were positive for HPV, whereas 3 of 34 (8.8%) nonmalignant samples were positive for HPV. This result shows a preferential association of HPV with tonsillar carcinomas. The correlations of the presence of HPV with the grade of differentiation and risk factors were not significant. Our data show that the HPV DNA microarray may be useful for the diagnosis and typing of HPV in large-scale epidemiological studies.     

Use of PGMY primers in L1 consensus PCR improves detection of human papillomavirus DNA in genital samples

The novel PGMY L1 consensus primer pair is more sensitive than the MY09 and MY11 primer mix for detection and typing with PCR of human papillomavirus (HPV) DNA in genital specimens. We assessed the diagnostic yield of PGMY primers for the detection and typing of HPV by comparing the results obtained with PGMY09/PGMY11 and MY09/MY11/HMB01 on 299 genital samples. Amplicons generated with PGMY primers were typed with the line blot assay (PGMY-line blot), while HPV amplicons obtained with the degenerate primer pool MY09/MY11/HMB01 were detected with type-specific radiolabeled probes in a dot blot assay (standard consensus PCR test). Cervicovaginal lavage samples (N = 272) and cervical scrape samples (N = 27) were tested in parallel with both PCR tests. The PGMY-line blot test detected the presence of HPV DNA more frequently than the standard consensus PCR assay. The concordance for HPV typing between the two assays was 84.3% (214 of 255 samples), for a good kappa value of 0.69. Of the 177 samples containing HPV DNA by at least one method, 40 samples contained at least one HPV type detected only with PGMY-line blot, whereas positivity exclusively with the standard consensus PCR test was found for only 7 samples (P < 0.001). HPV types 45 and 52 were especially more frequently detected with PGMY than MY primers. However, most HPV types were better amplified with PGMY primers, including HPV-16. Samples with discordant results between the two PCR assays more frequently contained multiple HPV types. Studies using PGMY instead of MY primers have the potential to report higher detection rates of HPV infection not only for newer HPV types but also for well-known genital types.     

Detection of human papillomavirus (HPV) using dot blot and Southern blot, hybridizing with a mixture of seven probes.

A previously presented method for the detection and typing of human papillomavirus (HPV) DNA has been modified for the simultaneous analysis of HPV types 6, 11, 16, 18, 31, 33 and 35. The method has two steps, where a dot blot test is used to exclude cases that do not hybridize with HPV-DNA. The remaining cases are then analysed by a Southern blot procedure, using a mixture of subgenomic probes for the simple and accurate analysis of HPV types. When the procedure was used for the analysis of clinical samples, patient groups at varying risk were found to differ with regard to the prevalence of HPV infections. Thus, the virus was detected in only 8.8% of otherwise healthy young women - i.e. women without clinical signs of HPV-related disease - as compared to 48% of women who also had cervical intraepithelial neoplasia (CIN). A similarly high prevalence was found in patients in whom CIN persisted (42%) as compared to those in whom the morphological lesion regressed to normal (8%).     

Human papillomavirus typing with GP5+/6+ polymerase chain reaction reverse line blotting and with commercial type-specific PCR kits.

BACKGROUND: Infection with human papillomavirus (HPV) is a necessary step in the progression to cervical cancer. Many methods for HPV testing are currently available, most developed to detect pools of HPV types. OBJECTIVES: To evaluate the HPV typing by molecular methods and to compare commercial kits with an established laboratory method. STUDY DESIGN: Eighty-four cervical samples found to be positive for HPV DNA by GP5+/6+-polymerase chain reaction-enzyme immunoassay-reverse line blotting (PCR-EIA-RLB) were re-tested with two commercial methods, INNO-LiPA and Amplisense HPV typing, able to identify the HPV type predicted by PCR-EIA-RLB in 76 and 67 samples, respectively. RESULTS: The INNO-LiPA assay revealed HPV DNA in 75/76 samples (98.7%; 95% CI, 0.93-0.99) that would contain HPV types identifiable by this assay. The Amplisense HPV assay revealed HPV DNA in 58/67 samples (86.6%; 95% CI, 0.76-0.93) containing HPV types detectable by this assay. For samples with a single infection, the unweighted kappa for concordance of HPV typing was 0.87 (95% CI, 0.78-0.97) for PCR-EIA-RLB versus INNO-LiPA, 0.94 (95% CI, 0.87-0.99) for INNO-LiPA versus Amplisense HPV, and 0.82 (95% CI, 0.70-0.94) for PCR-EIA-RLB versus Amplisense HPV typing. PCR-EIA-RLB revealed 12 multiple infections, INNO-LiPA revealed 14, and Amplisense HPV revealed 5. The agreement among tests for samples with multiple infections was lower, giving kappa values of 0.44 (95% CI, 0.18-0.70) for PCR-EIA-RLB versus INNO-LiPA, 0.52 (95% CI, 0.19-0.85) for PCR-EIA-RLB versus Amplisense HPV and 0.43 (95% CI, 0.12-0.74) for INNO-LiPA versus Amplisense HPV. CONCLUSIONS: In HPV-positive samples, the agreement among tests for HPV typing was high for single infections but markedly lower for infections with multiple HPV types.     

Novel Short-Fragment PCR Assay for Highly Sensitive Broad-Spectrum Detection of Anogenital Human Papillomaviruses

A novel set of polymerase chain reaction (PCR) primers, designated SPF1 and SPF2 and located in the L1 region, was developed for universal detection of human papillomavirus (HPV). A short PCR fragment (SPF) of only 65 pb was synthesized. SPF amplimers were detected in a microtiter-based hybridization system, using a mixture of oligonucleotide probes. The SPF system allowed detection of at least 43 different HPV genotypes. The clinical performance of the novel SPF system was assessed in three different patient groups. 1) Analysis of 534 cervical scrapes, obtained from treated patients, showed that the detection rate in 447 (83.7%) scrapes with normal cytology was significantly higher using the SPF system as compared with the universal primer set GP5+/6+ (P < 0.001). 2) The SPF assay detected HPV DNA in 299 (98.4%) of 304 scrapes with cytological dyskaryosis. 3) The SPF system detected HPV DNA in 100% of 184 formalin-fixed, paraffin-embedded cervical carcinoma specimens. In conclusion, the novel SPF system permitted universal and highly sensitive detection of HPV DNA in diverse clinical materials and may improve the molecular diagnosis and epidemiology of this important virus.     

A Human Papilloma Virus Testing Algorithm Comprising a Combination of the L1 Broad-Spectrum SPF10 PCR Assay and a Novel E6 High-Risk Multiplex Type-Specific Genotyping PCR Assay

Human papillomavirus (HPV) epidemiological and vaccine studies require highly sensitive HPV detection and genotyping systems. To improve HPV detection by PCR, the broad-spectrum L1-based SPF₁₀ PCR DNA enzyme immunoassay (DEIA) LiPA system and a novel E6-based multiplex type-specific system (MPTS123) that uses Luminex xMAP technology were combined into a new testing algorithm. To evaluate this algorithm, cervical swabs (n = 860) and cervical biopsy specimens (n = 355) were tested, with a focus on HPV types detected by the MPTS123 assay (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68, 6, and 11). Among the HPV-positive samples, identifications of individual HPV genotypes were compared. When all MPTS123 targeted genotypes were considered together, good overall agreement was found (κ = 0.801, 95% confidence interval [CI], 0.784 to 0.818) with identification by SPF₁₀ LiPA, but significantly more genotypes (P < 0.0001) were identified by the MPTS123 PCR Luminex assay, especially for HPV types 16, 35, 39, 45, 58, and 59. An alternative type-specific assay was evaluated that is based on detection of a limited number of HPV genotypes by type-specific PCR and a reverse hybridization assay (MPTS12 RHA). This assay showed results similar to those of the expanded MPTS123 Luminex assay. These results confirm the fact that broad-spectrum PCRs are hampered by type competition when multiple HPV genotypes are present in the same sample. Therefore, a testing algorithm combining the broad-spectrum PCR and a range of type-specific PCRs can offer a highly accurate method for the analysis of HPV infections and diminish the rate of false-negative results and may be particularly useful for epidemiological and vaccine studies.     

Comparison of human papillomavirus detection and typing by cycle sequencing, line blotting, and hybrid capture

We compared the results of human papillomavirus (HPV) detection and typing from 781 cervical samples assayed by three methods: L1 consensus PCR followed by cycle sequencing, L1 consensus PCR with biotinylated primers followed by hybridization to a line blot, and Hybrid Capture assay. Both PCR assays used L1 consensus PCR with primers MY09 and MY11. We evaluated the amplification efficiencies of both PCR assays and also compared the specific HPV types detected by each method. The samples positive by the Hybrid Capture assay were compared to the specific types detected by the PCR-based assays. The concordance between the two PCR assays in producing an HPV amplicon visible by gel electrophoresis or in detecting any HPV type was moderate: kappa values were 0.61 (95% confidence interval [CI] = 0.56 to 0.67) and 0.51 (95% CI = 0.46 to 0.58), respectively. The McNemar test for correlated proportions indicated that biotinylated PCR was less likely to produce a band (P = 0.001) and to detect an HPV type (P = 0.001) than the other PCR assay. In comparing the Hybrid Capture assay results with the HPV types detected by the PCR-based assays, we found that positivity by the Hybrid Capture assay for a number of samples may be due to cross-hybridization with HPV types not included in the Hybrid Capture assay probe cocktails.     

Molecular beacon-based real-time PCR method for detection of 15 high-risk and 5 low-risk HPV types

Detection of HPV infections requires a robust time-effective single-step method for efficient screening. A molecular beacon-based one-step multiplex real-time PCR system was developed to detect 15 high-risk (HPV types 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68) and 5 low-risk HPV types (HPV types 6, 11, 42, 43, 44). Molecular beacons detecting high-risk types are 5'-FAM-3'-DABCYL-labelled, molecular beacons for low-risk detection are 5'-TET-3'-DABCYL-labelled, while the internal control added before sample DNA extraction is detected by a 5'-FAM-TexasRed-3'-DABCYL wavelength-shifting molecular beacon. Accordingly, fluorescent data for HPV detection are collected at 530 nm for high-risk types, 560 nm in case of low-risk types and the reaction internal control is detected at 610 nm on a Roche LightCycler 2.0 instrument. The sensitivity for detected types varies between 22 and 700 copies/reaction. The clinical performance was tested on 161 clinical sample DNAs. The MB-RT PCR results were compared to the typing results obtained by the L1F/L1R PCR and hybridization-based system described previously, and the concordance rate between the two systems was 89.44%. The favorable characteristics shown by this multiplex single-step real-time HPV detection system make this promising approach worthy for further development and application for clinical screening.     

GeXP多重PCR技术用于人乳头瘤病毒HPV检测和分型的研究

目的建立一种基于GenomeLab^TM GeXP（GenomeLab eXpress Profiling）遗传分析系统的人乳头瘤病毒（HPV）分型新技术。方法针对5种中国人常见的HPV亚型（HPV6,11,31,33和52）的基因序列进行比对分析,设计型特异性引物,建立并优化GeXP多重PCR反应体系,评价其特异性和灵敏性,并应用于30份临床标本检测。结果本研究建立的GeXP多重PCR技术能够成功检测和鉴别5种不同亚型的HPV病毒,灵敏度高,特异性好。结论成功建立了一种新的快速同时检测和鉴别5种HPV亚型病毒的多重PCR方法,适用于临床HPV感染的实验室诊断与流行病学研究。