Detection of human papillomaviruses in tissue specimens

Nucleic acid tests for the detection of alpha human papillomaviruses

Testing for high-risk types of alpha human papillomaviruses (HPV) is an invaluable part of clinical guidelines for cervical carcinoma screening, management and treatment. In this comprehensive inventory of commercial tests for detection of alpha-HPV, we identified at least 125 distinct HPV tests and at least 84 variants of the original tests. However, only a small subset of HPV tests has documented clinical performance for any of the standard HPV testing indications. For more than 75% of HPV tests currently on the market, no single publication in peer-reviewed literature can be identified. HPV tests that have not been validated and lack proof of reliability, reproducibility and accuracy should not be used in clinical management. Once incorporated in the lab, it is essential that the whole procedure of HPV testing is subject to continuous and rigorous quality assurance to avoid sub-optimal, potentially harmful practices. Manufacturers of HPV tests are urged to put more effort into evaluating their current and future products analytically, using international standards, and for clinical applications, using clinically validated endpoints. To assist with analytical validation, the World Health Organization is developing international standards for HPV types other than HPV16 and HPV18 and is planning development of external quality control panels specifically designed to be used for performance evaluation of current and future HPV tests. There is a need for more competitively priced HPV tests, especially for resource-poor countries, and uniform test validation criteria based on international standards should enable issuing more competitive and fair tender notices for purchasing. Automation systems allowing large-scale testing, as well as further increases in clinical performance, are the main needs in the further improvement of HPV tests. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

Human papillomavirus genotype spectrum in studied group of Montenegrin women

The risk of high-grade lesions and carcinoma is known to correlate with specific high-risk HPV genotypes. The distribution of HPV types varies between countries and little is known about HPV distribution in our country. Therefore, the purpose of this study was to determine the range and frequency of HPV genotypes in studied group of women in Montenegro. HPV genotypes were determined using the method of enzyme restriction of PCR products amplified with group-specific primers MY09/MY11 and restricted with seven different restriction endonucleases. Out of the total number of women HPV infection was found in 1/5 of participants (20%). Genotyping performed in HPV DNA positive women shows that the HPV genotype 16 is dominant and present in more than 1/3 of the participants (36.8%). The second most frequent HPV infection is with HPV genotype 58 and it is found in 10.5% of participants. HPV 31 and HPV 6 infections are present in 7.9% of women, while infections with other genotypes were demonstrated individually by 2.6%. Multiple HPV infection was demonstrated in 18.4% and they are dominant in younger women (aged 25 to 30 years).

Comparison of the Abbott RealTime High Risk HPV test and INNO-LiPA HPV Genotyping Extra test for the detection of human papillomaviruses in formalin-fixed, paraffin-embedded cervical cancer specimens

Comparative evaluation of Abbott RealTime and Innogenetics INNO-LiPA on alternately processed formalin-fixed, paraffin-embedded specimens of 31 cervical cancers and 31 uterine myomas showed complete agreement in the detection of 14 assay-common HPV genotypes and partial genotyping of HPV-16 and HPV-18. The tissue preparation protocol was shown to be sample-to-sample contamination safe.

Detection and differentiation of human papillomavirus genotypes HPV-6 and HPV-11 by FRET-based real-time PCR

A real-time PCR (RT-PCR) assay was developed based on fluorescence resonance energy transfer (FRET) hybridization probe technology, allowing very sensitive and specific detection of HPV-6 and HPV-11, reliable differentiation of HPV-6 and HPV-11, as well as prototypic and non-prototypic HPV-6 genomic variants, in a single PCR reaction. The primers and probe were designed on the basis of multiple alignments of 74 HPV-6 E2 gene sequences and 20 HPV-11 E2 gene sequences. Testing on defined plasmid standards showed that the RT-PCR allowed simple and reliable identification of HPV-6 and HPV-11 using type specific amplification followed by probe-specific post-amplification dissociation analysis. Sensitivity, assessed by probit analysis at a 95% detection level, was 42.9, 43.4, and 25.3 DNA copies per assay for prototypic and non-prototypic HPV-6 variants and HPV-11, respectively. The results obtained by the developed assay on 51 HPV DNA-negative samples and 149 HPV DNA-positive samples, including 81 HPV-6 positive samples (19 prototypic and 62 non-prototypic HPV-6 variants), 28 HPV-11 positive samples, 10 samples of HPV-44 and HPV-74 (the closest relatives of HPV-6 and HPV-11) and 30 samples of 15 other important alpha HPV, showed complete agreement with those obtained with the INNO-LiPA human papillomavirus (HPV) Genotyping Assay and HPV-6 E2 and E6 gene sequencing.

Resolving repeatedly borderline results of Hybrid Capture 2 HPV DNA Test using polymerase chain reaction and genotyping

The Hybrid Capture 2 HPV DNA Test (hc2) (Digene Corporation, Gaithersburg, MD) is at present the only FDA approved assay for routine detection of human papillomavirus (HPV) infections. A significant analytical inaccuracy of the hc2 near to cut-off was reported recently. To address this problem, 240 samples with repeatedly borderline/equivocal/indeterminate hc2 results (samples with repeated RLU/CO values between 0.4 and 4.0) were tested using the PGMY09/PGMY11 consensus PCR and genotyping in order to resolve their high-risk HPV status. All PGMY09/PGMY11 PCR negative samples were tested in addition using CPI/IIg consensus PCR. A false negative rate of 11.3% and false positive rate of 19.1% were recorded in the samples with repeatedly borderline hc2 results. The corresponding hc2 false reactivity rates in 95 samples selected at random which were clearly hc2 negative (samples with RLU/CO values less than 0.4) and 124 samples selected at random which were clearly hc2 positive (samples with RLU/CO values more than 4.0) were 4.2% and 5.6%, respectively. The proportion of hc2 false reactivity increased with proximity to the hc2 cut-off value. According to the results of the present study, the introduction of an hc2 grey-zone and retesting of samples with repeatedly borderline hc2 results by an alternate HPV detection method, such as the PGMY09/PGMY11 consensus PCR and genotyping, is recommended.

Hybrid Capture II HPV Test detects at least 15 human papillomavirus genotypes not included in its current high-risk probe cocktail

BACKGROUND

Hybrid Capture II HPV Test (HCII) (Digene Corporation, Gaithersburg, MD) is a signal amplified hybridization microplate-based assay designated to detect 18 human papillomavirus (HPV) genotypes using two probe cocktails, for high-risk HPV genotypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68 and low-risk HPV genotypes 6, 11, 42, 43 and 44. At present, HCII is the only commercially available HPV assay with sufficient scientific data to support its performance in the clinical setting.

OBJECTIVES

To determine the specificity and accuracy of HCII high-risk probe cocktail for detection of 13 HPV genotypes included in the high-risk probe cocktail.

STUDY DESIGN

Cervical samples obtained from 325 women recognized as HPV positive using the HCII high-risk probe cocktail were included in the study. HPV genotypes were determined by restriction fragment analysis of PGMY09/PGMY11 polymerase chain reaction (PCR) products using seven restriction endonucleases.

RESULTS

A 450 bp fragment of HPV L1 gene was successfully amplified from 312 out of 325 samples. Of the 312 PCR-positive samples, 280 samples were associated with the expected high-risk HPV genotypes and 32 samples with the HPV genotypes not included in the HCII high-risk probe cocktail. Thus, HPV53 was detected in 8 samples, HPV66 in 4 samples, HPV54 in 3 samples, HPV6, HPV26, HPV70 each in 2 samples, and HPV11, HPV40, HPV42, HPV61, HPV73, HPV81, MM4, IS39, CP6108 each in 1 sample. In 2 samples, we were not able to determine the HPV genotype.

CONCLUSIONS

Our study shows that HCII high-risk probe cocktail detects at least 15 HPV genotypes not included in the current HCII high-risk probe cocktail. The potential impact of HCII high-risk probe cocktail cross-reactivity with phylogenetically related and unrelated HPV genotypes, including genotypes currently considered to be low-risk HPVs, remains to be determined.

Clinical utility of molecular detection of human papillomavirus in cervical samples by hybrid capture technology

High-risk human papillomaviruses (HPVs) are the primary risk factor for developing cervical carcinoma. Hybrid capture II HPV Test (HCII) is a standardized test for molecular detection of HPV DNA in cervical swabs. The aim of the study was to evaluate the clinical utility of the HCII when used in combination with conventional cytology in a group of 171 women who were followed-up with both, cytology and molecular testing for 3 years. At the end of the study, only women positive for high-risk HPV at baseline had retained or worsened cervical intraepithelial neoplasia (CIN). In most women who were negative for high-risk HPV, CIN had resolved within 3 years. These results are in concordance with earlier studies reporting the highly negative predictive value of high-risk HPV testing. Both cytology and high-risk HPV testing provide significant clinical information on the current cervical status of a woman. They should be used in combination for primary screening of CIN, which will provide a more selective and cost-effective follow-up.

Transitional cell metaplasia of the uterine cervix is related to human papillomavirus: molecular analysis in seven patients with cytohistologic correlation

BACKGROUND

Transitional cell metaplasia of the uterine cervix is an under-recognized entity in cervical pathology. The underlying etiology and biologic significance remains uncertain. The thin-layer cytology findings and association with human papillomavirus (HPV) have not been studied thoroughly.

METHODS

The authors retrospectively reviewed the clinical findings, thin-layer cytology and histologic features of pure transitional cell metaplasia of the uterine cervix occurring in seven perimenopausal or postmenopausal Chinese women at Pamela Youde Nethersole Eastern Hospital, Hong Kong, during the period from January, 1998 to April, 2001. Molecular techniques for HPV screening and genotyping using polymerase chain reaction and restriction fragment length polymorphism analysis were employed in the thin-layer cytology specimens and paraffin block material.

RESULTS

In all seven patients, transitional cell metaplasia represented an incidental histologic finding. It occurred in the ectocervix, transformation zone, endocervix, or vagina. Histologically, it resembled urothelium of the urinary bladder and was comprised of multilayers of mitotically inactive, immature epithelial cells with vertically aligned oval nuclei, fine chromatin, indistinct nucleoli, and conspicuous longitudinal nuclear grooves. The superficial cells were oriented more horizontally and contained pale-staining cytoplasm similar to umbrella cells. Features consistent with transitional cell metaplasia were identified in two of seven preoperative thin-layer preparations. Cytologically, the affected parabasal cells recapitulated the features that were seen in histologic sections. In addition to the bland nuclear morphology and longitudinal nuclear grooves, the cell borders appeared distinct, and the appearance of a perinuclear cytoplasmic halo was common. Sometimes, the metaplastic cells assumed a spindle shape and appeared as cohesive, streaming cell clusters. Molecular study successfully demonstrated the presence of HPV in all seven patients, mostly in the liquid-based cytology samples. In general, the viral DNA load was relatively low; and, for samples in which HPV genotyping was feasible, HPV type 58 was the prevalent genotype.

CONCLUSIONS

The current study demonstrates that transitional cell metaplasia of the uterine cervix is related to HPV. It also carries a distinctive cytologic appearance in thin-layer preparations. Based on the limited follow-up data from a small number of reported patients, transitional cell metaplasia seems to run an indolent clinical course. However, its peculiar association with HPV and its possible correlation, both morphologic and histogenetic, with cervical intraepithelial neoplasia need further investigation.

Typing of human papillomavirus by pyrosequencing

The possibility of using a new bioluminometric DNA sequencing technique, called pyrosequencing, for typing of human papillomaviruses (HPV) was investigated. A blinded pyrosequencing test was performed on an HPV test panel of 67 GP5+/GP6+ PCR-derived amplification products. The 67 clinical DNA samples were sequenced up to 25 bases and sequences were searched using BLAST. All of the samples were correctly genotyped by pyrosequencing and the results were unequivocally in accordance with the results obtained from conventional DNA sequencing. Pyrosequencing was found to be a fast and efficient tool for identifying individual HPV types. Furthermore, pyrosequencing has the capability of determining novel HPV types as well as HPV sequence variants harboring mutation(s). The method is robust and well suited for large-scale programs.

Schneiderian papillomas and carcinomas: a review

The ectodermally derived Schneiderian mucosa gives rise to an extremely varied collection of benign and malignant neoplasms. Prototypical of these are the Schneiderian papillomas (inverted, fungiform, and cylindrical cell) and their malignant counterparts. Human papilloma virus (HPV) is currently the leading candidate as a cofactor in the pathogenesis of the papillomas. Carcinomas arise in association with the papillomas in about a 10% frequency. The carcinomas may be synchronous or metachronous. Recurrences of the papillomas are the bane of surgeons. The magnitude of the recurrences is directly proportional to the completeness of removal with the best results obtained by techniques that afford the best operative exposure. A comparison of results by different surgical procedures is presented. Histologic features sought to predict recurrences or malignant transformation have, by and large, not been helpful. Keratinization and hyperkeratosis in papillomas, however, are suggested to be sufficiently ominous as to warrant further study.

In situ hybridization detection of single-copy human papillomavirus on isolated cells, using a catalyzed signal amplification system: GenPoint

The performance and drawbacks of GenPoint, which is a catalyzed signal amplification system for immunohistochemistry, have been evaluated for its ability to reveal human papillomavirus (HPV) DNA detected by in situ hybridization with biotinylated DNA probes. For this aim, formalin-fixed cell deposits from carcinoma cells of the uterine cervix, CaSki, SiHa, and HeLa, containing, respectively, 600 copies of HPV DNA type 16, 1-2 copies of HPV DNA type 16, and 10-50 copies of HPV DNA type 18, were used, and the GenPoint method (consisting of successive incubations with peroxidase-conjugated streptavidin, biotinyl tyramide, and peroxidase-conjugated streptavidin) was compared to immunoenzymatic revelation procedures involving either a one-step reaction (streptavidin-alkaline phosphatase or streptavidin-peroxidase), or a three-step reaction (anti-biotin mouse monoclonal antibody, rabbit anti-mouse antiserum, and mouse APAAP complex). In these conditions, after analysis with a bright-field microscope, GenPoint appeared the most sensitive method of revelation, easily allowing detection of 1-2 copies of HPV DNA on isolated cells by in situ hybridization.

Pagetoid dyskeratosis of the cervix: an incidental histologic finding in uterine prolapse

Pagetoid dyskeratosis, is considered a reactive process in which a small part of the normal population of keratinocytes is induced to proliferate. The lesion is characterized by pale cells resembling those of Paget's disease within the epidermis. These cells have been seen as an incidental finding in a variety of benign papules most commonly located in intertriginous areas. Among the inductors of the lesion, friction is suspected. To the best of our knowledge, these pale cells have not been reported in the cervix. We describe the location of the lesion in the ectocervix and the incidence of this lesion in a group of 100 unselected patients surgically treated for uterine prolapse. Another group of 100 unselected patients treated for uterine leiomyoma was used as a control. Pagetoid dyskeratosis was found in 37 cases (37%) of uterine prolapse and in five cases (5%) of uterine leiomyomas. The lesion is more common in uterine prolapse (p <0.001) and is not significantly associated with cornification of the epithelium (p = 0.72343). The cells of pagetoid dyskeratosis show an immunohistochemical profile different from the surrounding squamous cells characterized by premature keratinization. Pagetoid dyskeratosis cells have shown positivity for high molecular weight cytokeratin and negative reaction for low molecular weight cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, and human papilloma virus. Pagetoid dyskeratosis cells must be distinguished from artefactual clear cells, glycogen-rich cells, koilocytes, extramammary Paget's disease cells, and pagetoid spread of carcinoma cells to the cervix. In cases in which pagetoid dyskeratosis shows a florid expression, there is a hazard of overdiagnosis. The pathologist should be aware of the histologic features of pagetoid dyskeratosis in the ectocervix to avoid misdiagnosis and unnecessary treatment. Routine histologic study is usually sufficient to identify the lesion.