Basic concepts and practical applications of recombinant DNA techniques in detection of human papillomavirus (HPV) infection. Review article

Association between Helicobacter pylori infection and oral lichen planus: A meta-analysis

Background

Oral lichen planus (OLP) is a T cell-mediated autoimmune disease that affects the oral mucosa. Although Helicobacter pylori has been documented in subgingival and supragingival plaques and saliva, little is currently known about the relationship between Helicobacter pylori and OLP, warranting further research.

Methods

PubMed, Embase, Chinese National Knowledge Infrastructure (CNKI), and Web of Science databases were thoroughly searched for relevant articles published from inception until May 23, 2023.

Results

Due to high heterogeneity among the included studies (Tau2 = 2.16;χ 2  = 40.33, df = 6; I 2  = 85 %), we employed a random-effects model (REM). The forest plot revealed a significant correlation between H. pylori infection and OLP, with an odds ratio (OR) of 4.69 (95 % CI: 1.36 to 16.19; P < 0.01). Sensitivity analysis showed that the pooled ORs ranged from 3.69 (95 % CI: 1.01 to 13.44; P = 0.05) to 6.77 (95 % CI: 2.65-17.30; P < 0.001), and no single study significantly influenced the results when removed individually. Additionally, subgroup analysis was conducted to investigate the relationship between H. pylori infection and OLP and explore the sources of heterogeneity. Finally, Begg's test (P = 0.24) and Egger's test (P = 0.35) were performed on the included studies, and the results indicated no significant publication bias.

Conclusion

Our meta-analysis suggests a close association between H. pylori infection and OLP. Nevertheless, further research is warranted to validate these results in the future.

The Magnitude of the Association between Human Papillomavirus and Oral Lichen Planus: A Meta-Analysis

Background

The role of human papilloma virus (HPV) in oral lichen planus (OLP) is controversial.

Objectives

The primary aim of the current study is to calculate the pooled risk estimates of HPV infection in OLP when compared with healthy controls.

Methods

Bibliographic searches were conducted in three electronic databases. Articles on the association between HPV and OLP were selected from case-control studies or cross-sectional studies, following predefined criteria. Pooled data were analyzed by calculating odds ratios (OR) and 95% confidence interval (CI).

Results

Of the 233 publications identified, 22 case-control studies met the inclusion criteria. Collectively, 835 cases and 734 controls were available for analysis. The summary estimate showed that OLP patients have significantly higher HPV prevalence (OR: 6.83; 95% CI: 4.15–11.27) than healthy controls. In subgroup analyses, the association of HPV and OLP varied significantly by geographic populations. The ORs ranged from 2.43 to 132.04. The correlation of HPV and erosive-atrophic oral lichen planus (EA-OLP) (OR: 9.34) was comparable and well above that of HPV and non-EA-OLP (OR: 4.32). Among HPV genotypes, HPV 16 showed an extremely strong association with OLP (OR: 11.27), and HPV 18 showed a relatively strong one (OR: 6.54).

Conclusion

In conclusion, a significant association was found between HPV and OLP. The strength of the association varied across geographic populations, clinical types of OLP, and HPV genotypes. The results suggest that HPV might play an important causal role in OLP and in its malignant to progression.

Prevalence and trends of human papillomavirus in oropharyngeal cancer in a predominantly north Indian population

BACKGROUND

Human papillomavirus (HPV) prevalence in oropharyngeal squamous cell cancer (SCC) remains variable and studies have estimated that up to 60% may be positive.

METHODS

One hundred five treatment-naïve oropharyngeal SCC patients were included. HPV genotyping was done by consensus polymerase chain reaction (PCR) and reverse line-blot hybridization assay. HPV prevalence was co-related with sex, age, tobacco consumption, alcohol use, and high-risk sexual behavior.

RESULTS

HPV prevalence was 22.8%. No significant associations were seen between tobacco or alcohol consumption with HPV status. The mean number of lifetime sexual partners and indulgence in high-risk sexual behavior was significantly more in patients who are HPV positive. There were no significant associations between the 2 groups with respect to the stage of the tumor.

CONCLUSION

Results of this study confirms that patients who are HPV positive are younger, and with high-risk sexual behavior. We did not find any impact of smoking and alcohol consumption on HPV status.

Human papillomaviruses in oral carcinoma and oral potentially malignant disorders: a systematic review

OBJECTIVES

Human papillomavirus (HPV) in oral carcinoma (OSCC) and potentially malignant disorders (OPMD) is controversial. The primary aim was to calculate pooled risk estimates for the association of HPV with OSCC and OPMD when compared with healthy oral mucosa as controls. We also examined the effects of sampling techniques on HPV detection rates.

METHODS

Systematic review was performed using PubMed (January 1966-September 2010) and EMBASE (January 1990-September 2010). Eligible studies included randomized controlled, cohort and cross-sectional studies. Pooled data were analysed by calculating odds ratios, using a random effects model. Risk of bias was based on characteristics of study group, appropriateness of the control group and prospective design.

RESULTS

Of the 1121 publications identified, 39 cross-sectional studies met the inclusion criteria. Collectively, 1885 cases and 2248 controls of OSCC and 956 cases and 675 controls of OPMD were available for analysis. Significant association was found between pooled HPV-DNA detection and OSCC (OR = 3.98; 95% CI: 2.62-6.02) and even for HPV16 only (OR = 3.86; 95% CI: 2.16-6.86). HPV was also associated with OPMD (OR = 3.87; 95% CI: 2.87-5.21). In a subgroup analysis of OPMD, HPV was also associated with oral leukoplakia (OR = 4.03; 95% CI: 2.34-6.92), oral lichen planus (OR = 5.12; 95% CI: 2.40-10.93), and epithelial dysplasia (OR = 5.10; 95% CI: 2.03-12.80).

CONCLUSIONS

The results suggest a potentially important causal association between HPV and OSCC and OPMD.

Presence and Influence of Human Papillomaviruses (HPV) in Tonsillar Cancer

Tonsillar cancer is the most common of the oropharyngeal carcinomas and human papillomavirus (HPV) has been found to be present in approximately half of all cases. Patients with HPV-positive tonsillar cancer have been observed to have a better clinical outcome than patients with HPV-negative tonsillar cancer. Moreover, patients with tonsillar cancer and a high viral load have been shown to have a better clinical outcome, including increased survival, compared to patients with a lower HPV load in their tumors. Recent findings show that HPV-positive tumors are not more radiosensitive and do not have fewer chromosomal aberrations than HPV-negative tumors, although some chromosomal differences may exist between HPV-positive and -negative tonsillar tumors. Current experimental and clinical data indicate that an active antiviral cellular immune response may contribute to this better clinical outcome. These data are also in line with the findings that the frequency of tonsillar cancer is increased in patients with an impaired cellular immune system. Thus, therapeutic and preventive HPV-16 antiviral immune vaccination trials may be worthwhile, not only in cervical cancer, but also in tonsillar cancer.

The role of human papillomavirus in oral carcinogenesis

Human papillomavirus (HPV) infection with high-risk types 16 and 18 has widely been reported as one of the prominent mechanisms behind the development of cervical squamous cell carcinoma. Links between HPV and oral cavity cancer have been suggested as well, based on epidemiologic and molecular means, though the association is less well-established. It is likely that HPV plays a role in oral cavity carcinogenesis, though only in a small subset of cases. The difficulty in providing true causal evidence of HPV's role in oral cancer lies in our lack of understanding of the significance of mechanisms by which HPV leads to oral carcinogenesis, as well as limitations in the molecular analysis of HPV. Further studies are necessary for the contribution of HPV in oral cavity malignancy to be better demonstrated.

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.

Epidemiological aspects of human papillomavirus infection and cervical cancer in Brazil

OBJECTIVES

A study was conducted to determine the prevalence of HPV infection in cervical lesions of Brazilian women and to search for specific risk factors associated to progression to malignancy.

METHODS

Five hundred and fourteen paraffin-embedded biopsies obtained from female cervical lesions were classified according to the Bethesda System in low grade squamous intraepithelial lesion (LSIL), high grade SIL (HSIL) and squamous cell carcinoma (SCC). Specimens were tested for the presence of human papillomavirus (HPV) types 6/11,16/18 and 31/33/35 DNA using non-isotopic in situ hybridization.

RESULTS

HPV prevalence ranged from 85.6% in LSIL to 55.2% in SCC. Patients were analysed through an 8 year period: 27. 1% of the lesions spontaneously regressed while 43.6% persisted and 29.3% progressed to carcinoma. High risk types were present in 80.5% (Crude OR 13.8, P=0.0003) of the progressive lesions. Possible co-factors have also been evaluated: history of other sexually transmitted diseases, mainly syphilis, showed to be positively related to progression (Adjusted OR 13.0, P=0.0003) while oral contraceptive use and tobacco smoking were not significantly related to it (P>O.1). Association of two or more co-factors also proved to be related to progression.

CONCLUSIONS

Oncogenic HPV types 16 and 18 and history of other concurrent sexually transmitted diseases were found to be significantly associated with progression to cancer. Smoking and the use of oral contraceptives did not show a relation to cancer establishment, but when they were associated a significant co-operative role in progression was demonstrated. Our study indicated that HPV and other risk factors for cancer can act together, corroborating the observation of a poor prognosis for Brazilian women presenting SILs.

Failure to demonstrate human papillomavirus DNA in epithelial ovarian cancer by general primer PCR

One of the recent controversies with substantial clinical interest is the role of HPV in pathogenesis of ovarian cancer. The available highly conflicting data are based on analysis of 175 ovarian carcinomas so far. As an attempt to further elucidate this issue, the first systematic study of HPV detection in ovarian cancer was carried out using a highly sensitive general primer PCR (confirmed by hybridization for low- and high-risk HPV types separately) in a series of 98 histologically and clinically well-characterized epithelial ovarian malignancies. Despite the high (fg) sensitivity and a wide HPV type coverage of the technique used, all 98 ovarian carcinomas failed to demonstrate any signs of HPV DNA whatsoever. The preexisting 12 reports comprising a total of 175 ovarian tumors analyzed for HPV were summarized, giving highly discrepant results (i.e., detection rates from 0 to 100%) with the overall HPV DNA detection rate of 25.7%. The reasons for these discrepant findings are most probably technical. Our data are consistent with those of the majority of the most recent reports failing to disclose HPV DNA in ovarian neoplasia. The present completely negative results make the authors inclined to conclude that HPV is highly unlikely to play any causal role in the pathogenesis of epithelial ovarian neoplasia.

A novel method to culture laryngeal human papillomavirus-positive epithelial cells produces papilloma-type cytology on collagen rafts

A novel method to culture human papillomavirus (HPV) positive laryngeal epithelial cells is described. Biopsies of laryngeal papillomas and of HPV-positive laryngeal mucosa were first cultured as a monolayer in which irradiated laryngeal fibroblasts originally derived from a papilloma (PPLF-XR) patient served as feeder cells. When these fourth or fifth passage epithelial cells were transferred to allow growth on an organotypic growth base (collagen raft containing unirradiated PPLF), they grew as a multilayer. This layer showed features typical of HPV infection with koilocytosis, parakeratosis, and isolated dyskeratotic cells. Based on in situ hybridisation, the original tumour sections and epithelial cells from each monolayer passage, as well as the collagen raft sections, contained HPV DNA. Our results show that HPV-infected epithelial cells can be maintained during passages in monolayer culture and that PPLF can support the growth of these cells well. The monolayer cell culture and the collagen raft, the latter providing differentiation-promoting effects, appears to facilitate maintenance of the infected cells and of the viral genome.

Human papillomavirus and head and neck cancer: epidemiology and molecular biology

BACKGROUND

Human papillomaviruses (HPV) are known to cause cancers of the cervix and other anogenital tract sites. Molecular biology has provided some evidence as to the specific mechanisms involved in the HPV-related carcinogenesis. Epidemiologic and molecular biology studies have also suggested that HPV infection may be associated with cancers of the head and neck.

METHODS

This review summarizes the biology of HPV and its potential etiologic role in head and neck cancer. Published reports were used to determine the prevalence of HPV in benign, precancerous, and neoplastic lesions of the oral cavity, pharynx, and larynx. The prevalence was also examined by head and neck site, HPV type, and method of HPV detection. In addition, the occurrence of HPV in normal head and neck tissue, epidemiologic factors related to HPV infection, and clinical implications are discussed.

RESULTS

Overall, the frequency of HPV in benign and precancerous lesions ranged from 18.5% to 35.9%, depending upon the detection methodology. Based upon the most sensitive method of detection, polymerase chain reaction (PCR), the overall prevalence of HPV in head and neck tumors was 34.5% (416 of 1205 tumors). The majority of HPV-positive tumors contained the "high risk" HPV types 16 (40.0%) and 18 (11.9%). Among head and neck sites, HPV was most often detected in tumors of the oral cavity (59%), followed by the pharynx (43%), and larynx (33%). The frequency of HPV positivity in oral samples from healthy individuals ranged from 1% to 60%. A limited number of descriptive and analytic epidemiologic studies have indicated that age (<60 years) and sex (male) were associated with the presence of HPV in the tumor, whereas tobacco and alcohol use were not. The relationship between HPV and survival is unclear, with few comprehensive studies currently available.

CONCLUSIONS

The prevalence of HPV, particularly the high-risk types, suggests a potential etiologic role for the virus in head and neck cancer. Molecular biology has provided important data on the interaction of the HPV oncoproteins with genes important in cell cycle control. Nonetheless, more basic research is needed to describe the physical state of the virus in a variety of cell types and the interaction with other genes. In addition, epidemiologic research is required to further understand the association between HPV and demographic and other risk factors as well as possible routes of transmission. Finally, much work is warranted to provide a definitive assessment of the prognostic significance of HPV in head and neck cancer.

Detection of human papillomavirus in squamous cell carcinomas of the lung by polymerase chain reaction

Existing evidence supports the hypothesis that human papillomavirus (HPV) may play an etiologic role in the malignant transformation of squamous epithelial cells. Although HPV DNA has been identified in a high proportion of squamous cell carcinomas (SCC) of the cervix, anorectum, skin, and upper airways, few studies have tested for HPV in SCC of the lung. To confirm the presence of HPV in lung SCC, we tested for HPV DNA extracted from formalin-fixed tissues of 34 patients by polymerase chain reaction (PCR). DNA amplification was performed using HPV L1 consensus sequence primers (MY11 and MY09; Perkin-Elmer Cetus, Norwalk, CT) which recognize a broad spectrum of HPV types including 6, 11, 16, 18, 31, and 33, among many other known types, as well as at least 20 other unidentified types. PCR products were analyzed by agarose gel electrophoresis and Southern blot hybridization with [32P]-labeled generic HPV probes. HPV DNA positive cases were subsequently analyzed by slot-blot hybridization of the PCR products with specific probes for HPV types 6, 11, 16, 18, and 33. HPV type 18 was detected in two cases, including one case from a 44-year-old female and one from a 64-year-old male, with the remaining 32 cases negative. In situ hybridization for HPV DNA failed to detect HPV types 6/11, 16/18, or 31/33/35 in any of the cases. We conclude that a small proportion of cases of primary pulmonary SCC test positive for HPV type 18 but that the great majority of cases are not associated with HPV.

DNA-EIA to detect high and low risk HPV genotypes in cervical lesions with E6/E7 primer mediated multiplex PCR

BACKGROUND

Oncogenicity of human papillomavirus (HPV) DNA in premalignant and malignant uterine cervical diseases is mainly induced by E6/E7 open reading frame (ORF). The presence of an oncogenic HPV DNA may be a diagnostic marker for the detection of cytologically negative smears.

AIMS

To evaluate an original polymerase chain reaction enzyme immunoassay (PCR-EIA) for the detection and typing of oncogenic and non-oncogenic HPV types.

METHODS

The test was an original multiplex labelled PCR-EIA for the detection and typing of oncogenic and non-oncogenic HPV using three consensus sequence primers within the oncogenic E6/E7 ORF. One primer was dinitrophenyl (DNP) labelled and the DNP labelled amplimers could be further hybridised with specific biotinylated oligoprobes mixed in only two cocktails: oncogenic (16, 18, 31, 33, 35, 52, and 58) and non-oncogenic (6 and 11) HPV types in only two wells; then biotinylated oligoprobes were deposited in streptavidin-coated microplates. The PCR-EIA was validated on HPV plasmids (types 6, 11, 16, 18, 31, 35, 52, and 58) and used to evaluate cervical scrapes from 181 patients (median age 32 years) at high risk for cervical cancer.

RESULTS

HPV were detected in the cervical scrapes of 88 of 181 patients (48.6%); nine with non-oncogenic HPV (5.0%) and 79 with oncogenic HPV (43.6%) including 29 coinfections with oncogenic and non-oncogenic HPV. The number of oncogenic HPV infections increased with the presence of high grade lesions: 95.8% of the cervical scrapes from patients with high grade lesions contained oncogenic HPV compared with 32.1% of the specimens from patients without any lesions detectable by colposcopy and/or by cytological examination of the cervical smears. Moreover, 60% of cervical scrapes exhibiting low grade lesions contained oncogenic HPV.

CONCLUSIONS

This test is simple, specific, sensitive, safe, fast, reproducible, and easy to use in routine practice. Thus, it is possible to detect simultaneously on a simple cervical scrape, two kinds of HPV--oncogenic and non-oncogenic--in just two microplate wells with non-isotopic oligoprobes.

Detection of human papillomavirus DNA in genital lesions by enzymatic in situ hybridization with Fast Red and laser scanning confocal microscopy

Human papillomavirus (HPV) infection with potentially oncogenic types 16 or 18 is common in genital lesions especially in uterine carcinomas. In such lesions, in situ hybridization with non-radioactive probes is a powerful tool for the histopathologist to detect and type HPV DNA either on cell deposits or on tissue sections. The use of an immunohistochemical method involving alkaline phosphatase and Fast Red TR salt/naphthol AS-MX phosphate is proposed for use with conventional bright-field or fluorescence microscopy as well as by laser scanning confocal microscopy. The alkaline phosphatase-Fast Red reaction has the advantage of producing a red precipitate that permits the detection of in situ hybridization signals by bright-field microscopy, and of obtaining a strong red fluorescence characterized by a lack of bleaching when excited by a green light. Therefore, the alkaline phosphatase-Fast Red reaction is well adapted for observations by fluorescence and confocal microscopy, the latter method allowing the detection, in tissue sections of cervical intraepithelial lesions, of small punctate and large diffuse hybridization signals, considered as integrated and episomal states of HPV DNA respectively. The combination of in situ hybridization with the alkaline phosphatase-Fast Red reaction and confocal microscopy is particularly convincing when hybridization signals are of small size and/or of low fluorescence intensity, especially if they are present in various focal planes; in such conditions, infected cells are easily detected by three-dimensional reconstruction. Therefore, this combination is a suitable method for identifying and characterizing HPV DNA in cells and tissue sections.

Human papillomavirus and bladder cancer

Bladder cancer remains an important cause of oncological morbidity and mortality in women. Known etiological agents include smoking and exposure to certain industrial chemical compounds, though the origin of the majority of cases remains unknown. Human papillomavirus infection is also common in women and has been closely linked to the development of carcinoma of the cervix. It has been suggested that infection with HPV may also be an important factor in the subsequent development of bladder cancer. A number of studies using various techniques of molecular biology have looked at the relationship between HPV infection and bladder cancer. Although the results are somewhat conflicting, the overall picture would suggest little involvement of HPV in the evolution of bladder cancer, except possibly in a small group of patients who are immunocompromised.

Human papillomavirus infection and cervical cancer in Brazil: a retrospective study

Two hundred and thirty paraffin-embedded biopsies obtained from female cervical lesions were tested for the presence of human papillomavirus (HPV) types 6/11, 16/18 and 31/33/35 DNA using non-isotopic in situ hybridization. Specimens were classified according to the Bethesda System in low grade squamous intraepithelial lesion (LSIL), high grade SIL (HSIL) and squamous cell carcinoma (SCC). HPV prevalence ranged from 92.5% in LSIL to 68.5% in SCC. Benign types were prevalent in LSILs while oncogenic types infected predominantly HSILs and SCC. HPV infection showed to be age-dependent, but no significant relation to race has been detected. Patients were analyzed through a five-year period: 20.7% of the lesions spontaneously regressed while 48.9% persisted and 30.4% progressed to carcinoma. Patients submitted to treatment showed a 19.4% recurrence rate. High risk types were present in 78.6% (CrudeOR 13.8, P = 0.0003) of the progressive lesions, and in 73.7% of the recurrent SILs (COR 19.3, P = 0.0000001). Possible co-factors have also been evaluated: history of other sexually transmitted diseases showed to be positively related either to progression (Adjusted OR 13.0, P = 0.0002) or to recurrence (AOR 17.2, P = 0.0002) while oral contraceptive use and tobacco smoking were not significantly related to them (P > 0.1). Association of two or more co-factors also proved to be related to both progression and recurrence, indicating that they may interact with HPV infection in order to increase the risk of developing malignant lesions.

Human papillomavirus in oral premalignant lesions

The aetiology of oral premalignant lesions is generally accepted to be multifactorial. Tobacco and alcohol are established as important cofactors in malignant development in the oral cavity, but in addition microorganisms, such as human papillomavirus (HPV), have gained much interest over the past decade. For many years, HPV has been accepted as an important cofactor in the development of cervical cancer, originating from a mucous membrane with similarities to the oral mucosa. 49 patients with oral premalignant lesions and 20 control patients with normal oral mucosa and no history of HPV infection were examined for the presence of HPV by immune histochemical staining using the peroxidase anti-peroxidase technique (PAP), DNA-DNA in situ hybridisation (ISH), and polymerase chain reaction (PCR) analysed by Southern blot hybridisation with an HPV 16 specific probe. The investigations revealed that HPV was found in 62.5% of the verrucous leucoplakias, 50.0% of the erythroplakias, 45.5% of the homogeneous leucoplakias, 33.3% of erythroleucoplakias and in 12.5% of the nodular leucoplakias. An overall HPV detection rate in the examined premalignant lesions was 40.8% and no patients in the control sample were positive. Concerning oral cancer development, it seems likely that HPV may be a cofactor, as 100% of patients who developed oral cancers within 4-12 years were all positive for HPV, one being positive for HPV 16.

A rapid microwave-in situ hybridization method for the definitive diagnosis of oral hairy leukoplakia: comparison with immunohistochemistry

As a diagnostic technique, in situ hybridization requires a long processing time, a degree of expertise and may be difficult to handle routinely in some laboratories. To simplify the in situ hybridization method, we have modified a microwave in situ hybridization technique and applied it to oral hairy leukoplakia (OHL) biopsies obtained from 10 HIV-seropositive patients (definitively diagnosed by a conventional in situ hybridization technique) with appropriate controls. It was necessary to design a novel chamber to avoid drying of sections during the hybridization step. This modified microwave in situ hybridization technique was equispecific and equisensitive to the conventional technique and it shortens the hybridization time from overnight incubation to 14 minutes. To determine the sensitivity of our microwave in situ hybridization method we applied it to previously documented tongue tissue obtained from an AIDS autopsy without clinical evidence of OHL, but found to contain Epstein-Barr virus (EBV) by conventional in situ hybridization. This tissue specimen acted as a low EBV copy number, positive control. The sensitivity of immunohistochemistry using three different commercial detection kits was compared to that of in situ hybridization on the same tissues, following optimisation steps. This included the use of 2 cycles of primary and biotinylated secondary antibodies (antibody double cycling). Clearly positive signals for EBV were detected in all OHL biopsies with the Vectastain Elite ABC and the Histostain-SP kits. The sensitivity of the three commercial detection kits was evaluated at immunohistochemistry level by their application to the low-EBV copy number positive control specimen. Signals for EBV antigen in the low copy number positive control specimen were obtained only with the Vectastain Elite ABC kit. This indicates that, in this application, use of the Vectastain Elite ABC kit gives comparable sensitivity for immunohistochemistry to that found by in situ hybridiation.

The association of vascular proliferation with HPV status and epithelial PCNA positivity in cervical intraepithelial lesions

In this study we investigated the number of blood vessels and vascular proliferation in subepithelial areas of 80 cervical condylomas and cervical intraepithelial neoplasias (CIN). The number of blood vessels was determined by counting factor VIIIRAg-positive vascular channels in areas beneath the epithelial lesions. Vascular proliferation was evaluated by determining the number of proliferating cell nuclear antigen (PCNA)-positive endothelial cells in the subepithelial connective tissues. The results were compared with the expression of human papillomavirus (HPV) DNA subgroups (6/11 (low-risk) and 16/18/31/33/35 (high-risk) of the lesions, as determined by dot-blot and in situ hybridization, and with epithelial cell proliferation as determined by immunohistochemistry for PCNA. Also p53 immunohistochemistry of the lesions was performed. Even though CIN II-III lesions on average contained more factor VIIIRAg-positive blood vessels compared to condylomas and CIN I lesions, no significant association was found between their number and the degree of dysplasia. However, moderate or strong PCNA staining in vascular endothelial cells was seen significantly more often in CIN II-III lesions than in condylomas and CIN I lesions (p = 0.008): 34/80 (45%) cases contained detectable HPV DNA as determined by dot-blot or in situ hybridization. There was no correlation between the presence or absence of HPV DNA and the number of PCNA-positive endothelial cells. Nine cases showed p53-positive cell nuclei and in three cases there was more than 1% positive nuclei in the lesion. No association was found between the vascularity or the number of PCNA-positive endothelial cells and the p53 immunoreactivity. The increased proliferative activity of endothelial cells in CIN II-III lesions suggests that they are angiogenically more active than condylomas and CIN I lesions. This activity does not, however, depend on the HPV or p53 status. This is the first report in which endothelial cell PCNA positivity was used as a marker for vascular proliferation.

Human papillomavirus infection and transitional cell carcinoma of the bladder. Immunohistochemistry and in situ hybridization

The aim of the present research was to investigate human papillomavirus (HPV) infection by means of immunohistochemistry and in situ hybridization in 76 bladder cancer specimens. A biotinylated DNA probe that recognizes HPV 6/11, HPV 16/18 and HPV 31/33/35 was used for in situ hybridization. A polyclonal antibody recognizing HPV capsid antigen (HPVcAg) was used for immunohistochemistry. In situ hybridization and immunohistochemistry were developed by alkaline phosphatase and immunogold-silver techniques respectively. Our results showed that 25 (32.8%) out of 76 bladder carcinoma specimens reacted with HPVcAg. Twelve (15.7%) out of 76 cases were positive for HPV 16/18-DNA using non-isotopic in situ hybridization. Sixteen cases had koilocytosis. No positive signals were found for HPV 6/11 or 31/33/35-DNA probes.

Detection of human papillomavirus in oral lesions using commercially developed typing kits

Biopsy material from 20 oral lesions (19 condylomas and 1 squamous papilloma) previously shown to contain human papillomavirus (HPV) 6 and HPV 11 sequences by in situ hybridization were examined using 3 commercially available HPV typing kits. Sensitivity and specificity were compared with in-house methods. Previous in situ hybridization had detected HPV 6b in 11 (55%) of the biopsies, HPV 6 and 11 in 7 (53%) and HPV 11 alone in 1 biopsy. Only one of the commercial assays (assay 1) detected HPV in all 20 biopsies (11 positive for HPV 6b only, 1 for HPV 11 only and 7 for HPV 6b and 11). The wide spectrum probe of assay 2 detected HPV in only 10 (50%) of the biopsies, and in a further 2 biopsies the hybridization results were difficult to interpret because of background staining. Assay 3 used a combined HPV 6/11 probe and detected HPV in 15 (75%) of the biopsies. Clear hybridization signals were demonstrated in the intermediate and upper layers only of squamous epithelium, as expected from the known association of HPV replication with epithelium differentiation. In most specimens background levels were not a problem, and all commercial assays were easy to use. The findings are discussed in the context of the digestion procedures, sensitivity of the probes provided and the conditions of hybridization, all of which would influence the detection of HPV.

Detection and typing of human papillomavirus by single hybridization

A rapid and non-radioactive molecular hybridization test was developed which simultaneously detects and types different human papillomaviruses (HPV) DNA in fresh and paraffin-embedded clinical specimens. The method includes reverse blot hybridization between different recombinant HPV plasmids immobilized on nylon membrane and probe of cellular DNA amplified and biotin- or digoxigenin-labeled by the polymerase chain reaction (PCR). PCR protocol using consensus primers includes the mixing of Taq polymerase at high temperature (Hot-Start) and the addition of the hapten-conjugated nucleotide after the first ten cycles of amplification. The sensitivity level of this method resulted in detecting about 50 copies of HPV 16 for sample, independently of hapten used. The specificity of the typing method was also validated by more laborious and conventional analyses such as Southern-blot or PCR followed by several hybridizations with specific probes. Using this test HPV-11, -16, -18, -31 and -35 were typed in a number of samples from patients attending hospital. The method appears suitable for the handling of clinical samples in a selected population screening for type specific infections by HPV.

Papillomavirus-associated balanoposthitis

OBJECTIVE

To assess whether there might be an association between genital papillomavirus infection (GPVI) and balanoposthitis.

DESIGN

Retrospective HPV DNA examination of biopsy specimens from 23 men suffering from balanoposthitis and exhibiting acetowhite lesions that were penoscopically and histologically concurrent with HPV infection.

SETTING

The STD clinics at Karolinska Hospital and South Hospital, Stockholm, Sweden.

PARTICIPANTS

Randomly selected men attending with long-lasting and/or recurrent penile symptoms and exhibiting a clinical picture of balanoposthitis, who revealed a penoscopical and histopathological picture of epidermal lesions that were concordant with accepted criteria for typical or conspicuous GPVI. Asymptomatic controls were selected retrospectively on the basis of identical penoscopy and histology criteria.

RESULTS

A history of previous condylomata was obtained in eight (35%) of 23 men. At penoscopic evaluation tiny condylomatous lesions were observed in five (22%) patients. The in situ hybridisation (ISH) assay using specific probes for the HPV types 6/11, 16/18, 31/33 and 42 was positive in 13/23 (56%) of the patient samples, but in only 26% of the 19 control samples. In patient biopsies the oncogenic HPV types 16/18 and/or 31/33 were found in 7/13 samples, whereas HPV 6/11 and/or 42 were present in another six cases. PCR performed on the ten ISH negative patient biopsies, were negative in all cases.

CONCLUSION

Symptoms included redness, itching, burning, tenderness, dyspareunia, fissuring and in two cases penile oedema and inguinal adenopathy. All patients fulfilled penoscopical and histopathological criteria for HPV infection. We demonstrate some tentative evidence that HPV might be associated with long-lasting balanoposthitis, although our data still are circumstantial for a causative association. The results also elucidate the diversity in clinical presentation of GPVI.

Detection of HPV DNA in oral carcinoma using polymerase chain reaction together with in situ hybridization

This study determined the prevalence of human papillomavirus 16/18 DNA in deparaffinized oral carcinoma specimens on slides with the use of the different sensitivities of in situ hybridization and a technique that combines polymerase chain reaction and in situ hybridization. Human papillomavirus DNA was not detected in the 30 biopsy specimens analyzed by in situ hybridization alone using biotinylated DNA probes specific for human papillomavirus 16/18. Twenty of 30 specimens (66.7%) were found to have human papillomavirus DNA (p < 0.001) with the use of the polymerase chain reaction-in situ hybridization technique. Human papillomavirus 16 was detected in 18 of 26 specimens (69.2%), and 7 of 25 carcinomas (28%) were found to contain human papillomavirus 18. Dual infections were present in 5 of 21 (23.8%) specimens. Human papillomavirus DNA was more prevalent in men (75%) than women (57.1%). However, there was no difference in the mean age of patients with oral carcinoma (men, 67.8 years; women, 67.5 years) who had human papillomavirus and those who did not (67.2 years). Carcinomas associated with dual infections occurred at a lower mean age (59.4 years) than those associated with a single human papillomavirus type (p < 0.005). We conclude that the polymerase chain reaction-in situ hybridization technique enhances our ability to demonstrate human papillomavirus types highly associated with oral squamous cell carcinoma.

Laser scanning confocal microscopy and quantitative microscopy with a charge coupled device camera improve detection of human papillomavirus DNA revealed by fluorescence in situ hybridization

Epithelial cervical CaSki, SiHa and HeLa cells containing respectively 600 copies of human papillomavirus (HPV) DNA type 16, 1-2 copies of HPV DNA type 16 and 10-50 copies of HPV DNA type 18 were used as model to detect different quantities of integrated HPV genome. The HPV DNA was identified on cell deposits with specific biotinylated DNA probes either by enzymatic in situ hybridization (EISH) or fluorescence in situ hybridization (FISH) involving successively a rabbit anti-biotin antibody, a biotinylated goat anti-rabbit antibody and streptavidin-alkaline phosphatase complex or streptavidin-fluorescein isothiocyanate complex. With brightfield microscopy and EISH, hybridization spots were observed in CaSki and HeLa cells but hardly any in SiHa cells. With fluorescence microscopy and FISH, hybridization spots were clearly seen only on CaSki cell nuclei. In an attempt to improve the detection of low quantities of HPV DNA signals revealed by FISH, laser scanning confocal microscopy (LSCM) and quantitative microscopy with an intensified charge coupled device (CCD) camera were used. With both LSCM and quantitative microscopy, as few as 1-2 copies of HPV DNA were detected and found to be confined to cell nuclei counterstained with propidium iodide. Under Nomarski phase contrast, a good preservation of the cell structure was observed. With quantitative microscopy, differences in the number, size, total area and integrated fluorescence intensity of hybridization spots per nucleus were revealed between CaSki, SiHa and HeLa cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of human papillomavirus type 16/18 DNA in cervicovaginal cells by fluorescence based in situ hybridization and automated image cytometry

Automatic fluorescence image cytometry (AFIC) is a fast, sensitive, and reliable approach for screening slide-based clinical specimens. In this study, we applied AFIC to identify cancer-associated human papillomavirus (HPV) genotypes 16 and 18 in individual cells of cervical smears using a sensitive fluorescence based in situ hybridization (FISH) assay. HPV sequences were labeled by FISH and the cells imaged using an epi-fluorescence microscope coupled to a low-light color CCD camera. Before application to clinical specimens, AFIC was assessed using fluorescent calibration beads and cervical cancer cell lines containing known numbers of integrated HPV genomes per nucleus. Assessment showed that our AFIC had a linear response, was quantitatively accurate, and had the sensitivity to detect one HPV genome per nucleus. After acquisition of images, computer algorithms identified every cell nucleus (via a fluorescent DNA counterstain) and quantified the FISH signal per nucleus. AFIC was employed to screen 27 patient specimens for HPV 16/18, of which 12 were positive. The HPV status of the specimens positively correlated with the pathological diagnosis, and since AFIC automatically and correctly located every cell, it was possible to directly compare morphology and HPV status in the same cell. In conclusion, the combination of FISH and AFIC is a sensitive and quantitative method to detect high risk HPV sequences in cervical smears.

Fast solid support detection of human papillomavirus in in vitro amplified DNA using a DNP-anti DNP monoclonal antibody couple

In some anogenital lesions the detection of certain types of human papilloma virus, especially oncogenic types, is of interest. In a first step during a prospective study, we compared two methods for the detection of human papillomavirus (HPV) DNA in clinical samples: Southern blotting followed by hybridization with a cloned radioactive genomic probe and a classical polymerase chain reaction (PCR) followed by hybridization with a 32P-labelled oligonucleotide probe. 118 biopsies and swabs were examined for HPV 6/11, 16, 18 and 33, 67 positive reactions were found by both methods, 5 positives only by PCR and 2 positives only by Southern blot for unidentified HPV. Patients with anogenital condylomas, dysplasias and carcinomas or asymptomatic patients were studied. Most high grade (II and III) dysplasias were associated with HPV 16 and HPV 18. Condylomata lesions and low grade dysplasia (grade I) were associated mostly with HPV 6/11, mixed type of HPV, less frequently with HPV 16 or HPV 18. As a second step a nested PCR coupled to solid support detection method was used as described by Sauvaigo et al. (1990) Nucleic Acids Res. 18, 3175-3183) to study a panel of 30 previously qualified different HPV DNA extracts. In this procedure the second round of PCR amplification involves biotinylated and dinitrophenylated labelled primers allowing the capture of PCR amplified HPV DNA sequences on streptavidin coated tubes and its revelation. We describe an improvement of HPV DNA detection by means of single-step immunoenzymatic revelation involving anti-DNP monoclonal antibodies conjugated to horseradish peroxidase enzyme. A perfect correlation with the previous results was obtained. This solid support method allows a faster and easier HPV typing compared to methods using membrane transfer.

Depletion of Langerhans cells in cervical HPV infection is associated with replication of the virus

We studied the quantity of Langerhans cells in 36 patients with cervical human papillomavirus (HPV) infection. Significantly fewer Langerhans cells (p < 0.05) were found in patients with compared to those without DNA tetraploidy. Similarly, patients positive for HPV 16/18 DNA by in situ hybridization or antipeptide IgA antibodies to HPV 18 tended to have fewer Langerhans cells than those negative for HPV 16/18 DNA or IgA antibodies. Our results suggest that depletion of Langerhans cells is associated with productive HPV 16/18 infection in the cervical epithelium.

Anogenital warts in children

Fourteen children presenting with anogenital (AG) warts and their close family members were studied; 28.6 and 8.3% of presenting children and other child household members, respectively, had non-genital cutaneous warts; 42.8% of children with AG warts had one or more adult household member with common hand warts. Fifty per cent of all mothers had subclinical cervical papilloma virus (PV) infection; only one male adult had subclinical PV infection of the penis without concurrent AG warts. Of the children with AG warts 42.8% had one or more adult household member with AG warts. Human papilloma virus (HPV) deoxyribonucleic acid (DNA), type 6/11 most frequently, was detected in 38.5% AG wart biopsies from children, and 67% AG wart biopsies from adults. HPV 31/33/35 was detected in 28.5% of cervical preneoplasias and type 6/11 in the one case of subclinical PV infection of the penile shaft. Detection of HPV types 6/11, 16/18, or 31/33/35 in AG warts in children was significantly associated with vertical (from an HPV-infected maternal birth canal during vaginal delivery) or sexual transmission of these warts (Fisher exact probability P = 0.031).

Typing of human papillomavirus DNAs by restriction endonuclease mapping of the PCR products

The polymerase chain reaction (PCR) for the diagnosis of human papillomavirus (HPV) infections, and in particular for the study of cervical HPV-associated lesions, is used widely. We identified a novel set of universal primers that are able to amplify a fragment spanning the E1 open reading frame (ORF) from different mucosotropic HPV types. A restriction endonuclease digestion of the amplified products is suggested for accurate typing. In particular, AluI digestion of the amplified fragments yields a distinctive fragment pattern for each 'high-risk' (16, 18, 31 and 33) HPV sequence, thus distinguishing them from 'low-risk' (6b and 11) HPV sequences.

Influence of fixation on human papillomavirus DNA detection in frozen and embedded paraffin lesions by in situ hybridization with biotinylated probes

Series of frozen or paraffin-embedded tissues from various body sites, taken from non-immunosuppressed or immunosuppressed patients with persistent papilloma lesions were examined for the presence of group specific antigen from human papillomavirus (HPV) by indirect immunofluorescence or HPV DNA by in situ hybridization with biotinylated probes. We have shown that it is possible to detect HPV DNA after fixation of tissues in neutral formalin, Bouin's or Baker's solution. However, the sensitivity was reduced as compared to frozen tissues. The HPV DNA was detected in nuclei of heavily infected epithelial cells such as plantar or hand warts or in dispersed cells containing high copy numbers of HPV DNA from lesions such as squamous cell carcinomas or keratoacanthomas. In premalignant or malignant lesions of both immunosuppressed or non-immunosuppressed patients, HPV DNA was rarely detected after fixation. HPV types commonly described for skin and genital samples were identified in non-immunosuppressed patients, whereas in transplant recipients oncogenic HPV type 16 was identified in benign warts as well as in premalignant or malignant lesions. Positive reactions with several HPV types were more frequent in lesions from grafted patients than from the normal population. Virus antigen was detectable more frequently in frozen sections than in fixed tissues. Our findings indicate that in situ hybridization is an appropriate and rapid technique to study the presence of HPV infection. However, numerous controls are needed to avoid misinterpretations.

Human papillomavirus in cervix carcinoma and condylomata acuminata--identification of HPV-DNA by improved dot-blot-hybridization

Using the benzoylated naphthoylated DEAE cellulose method (BND-method) we have designed a more efficient approach for the detection of human papillomavirus-DNA (HPV-DNA) via dot-blot and hybridization. Biopsy material from anogenital warts (40 patients), invasive carcinoma uteri (12 patients) and normal controls (20 patients) were studied for the presence of HPV-DNA. Phenol extracted DNA from representative lesions was loaded onto a pretreated nitrocellulose filter, was incubated under stringent conditions with 32-P-dCTP labelled HPV-DNA and exposed to a Kodak X-OMAT film. DNA of HPV types 11, 16, 18 were cloned into plasmid vectors. The common, time-consuming caesium-chloride density-gradient centrifugation used for purification of plasmid DNA (20-36 h), was substituted by the BND-method (15 min). Complete HPV genomes were excised using the restriction endonucleases Eco RI and Bam HI. The HPV-DNA fragments obtained were then electroeluted using the 'Bio-Trap' method and subsequently labelled with 32P-dCTP by nick translation. Without resorting to more complex and sensitive technology, such as the polymerase chain reaction, efficiency of specific analysis of large numbers of cervical samples and condylomata was achieved without loss of accuracy or increased costs. The time required for HPV identification from biopsy or sample receipt was shortened considerably (approximately 50%).

High frequency of human papillomavirus infection in carcinoma of the urinary bladder

BACKGROUND AND METHODS

The prevalence of type 6, 11, 16, 18, and 33 human papillomavirus (HPV) was investigated with the polymerase chain reaction (PCR) on formalin-fixed, paraffin wax-embedded material, including 48 neoplastic and 21 normal urinary bladder specimens. The PCR-amplified DNA were analyzed by gel electrophoresis and dot blot and Southern blot hybridization. Some tissues were tested further by nonisotopic in situ hybridization.

RESULTS

HPV DNA was detected in 39 (81%) of 48 carcinomas and 7 (33%) of 21 normal urinary bladder specimens. The presence of high-risk HPV (types 16, 18, and 33) was increased significantly in carcinoma cases (62%) as compared with normal specimens (14%) (P less than 0.01). Similarly, multiple HPV infections were significantly higher in carcinoma (60%) than in the normal tissues (5%) (P less than 0.01). The overall and high-risk HPV infections in both neoplastic and normal specimens were distributed almost equally in male and female patients. There was no significant correlation between positive results for HPV and histologic grades of the carcinoma.

CONCLUSIONS

These results demonstrate that the urinary bladder in both sexes is another site where infection with the common genital tract HPV may carry a risk of malignant transformation.

Implications of rDNA technology in the microbiology laboratory

The present and potential future roles in service and research microbiological laboratories of recombinant DNA (rDNA) techniques (nucleic acid hybridization, nucleic acid amplification, in situ hybridization, pulsed field gel electrophoresis) are described. Applications rDNA technology include the detection of micro-organisms; an approach to the understanding of their role in disease pathogenesis and provision of alternative strategies for studying the epidemiology of infectious diseases.

Human papillomaviruses in normal oral mucosa: a comparison of methods for sample collection

The prevalence of six genital genotypes of HPV was assessed in the clinically normal oral mucosa of an adult Caucasian population, and three methods of sample collection compared. HPV DNA was detected in the mouth of 60% of 60 subjects. HPV 16 was the most prevalent genotype, and positive samples were found most frequently in men over 50. A 3% sucrose mouthwash produced more positive results (51%) than mucosal scrapes of three separate sites (45%) or buccal mucosal biopsies (12%). There was no association of a positive result for HPV DNA with any particular mucosal site. A mouthwash was the preferred single screening method for epidemiologic studies of HPV DNA in the mouth, but the greatest yield of positive samples was obtained if multiple sampling techniques were employed.

Detection of multiple types of human papillomavirus in a giant condyloma from a grafted patient. Analysis by immunohistochemistry, in situ hybridisation, Southern blot and polymerase chain reaction

Immunosuppressed patients such as transplant recipients are known to develop multiple lesions suggestive of human papillomavirus (HPV) infection. A giant anal condyloma was obtained from a transplant patient; several fragments taken from different areas were examined for the presence of HPV DNA using in situ hybridisation, polymerase chain reaction (PCR) and Southern blot. Typical koilocytes were seen in routinely stained tissue sections, suggesting an HPV infection; furthermore, group specific HPV antigen was detected in one of four frozen fragments. Different results were obtained by in situ hybridisation according to the fragment tested. HPV types 6/11 were detected in each of the five fragments, frozen or fixed in Bouin's or formalin solutions. However, the number of HPV DNA positive cells and the intensity of the reaction greatly varied with the specimen. HPV 16 and 18 probes also reacted positively with the sample fixed in formalin; a stronger signal was observed with HPV 18 in one large focus than with HPV 16. HPV type 5 was detected in a few isolated cells of two frozen fragments. With the Southern blot technique, the profile of an HPV 6/11 was seen only in one of two frozen fragments; in this case, the bands were intense. A slight positive reaction was also obtained in one frozen fragment with HPV 16 probe. Four frozen fragments were analyzed with PCR: HPV 6/11 was detected in each fragment; HPV 18 was detected in the four samples but with different intensities; HPV types 5 and 16 did not show any positive signal. In conclusion, the lesion is an example of infection with several HPV types, demonstrated by three different techniques. This suggests the need for careful dermatological or colposcopic follow-up of transplant recipients, in order to prevent possible malignant transformation of anogenital lesions.

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%).

What's new in diagnosis and treatment of HPV-associated cervical lesions

The human papilloma virus (HPV) has been subject to intense discussion during the last decade, as evidence has accumulated to strongly suggest that viruses play an essential part in the genesis of cervical neoplasms. The contamination rate of the female population is reported to range between 5 and 80%, depending on the modality of detection. Many indications almost reliably suggest the oncogenicity of certain HPV-types. The highest progression rate was found in HPV 16 lesions, followed by HPV 18 lesions. In our material the incidence of HPV 16/18 and 31/33 infections compared to 6/11 was elevated in patients with cervical intraepithelial neoplasia (CIN) compared to women with non-CIN lesions. The exact histologic diagnosis of CIN lesions is essential for a differentiated therapy. Our data indicate that mild and moderate CIN lesions are detected more frequently by Pap smear and colposcopically directed punch biopsy than by cervical smears alone. Histological diagnosis and HPV-typing by in-situ hybridisation offers the possibility to establish a differentiated therapy, e.g. by way of close follow-up, local destruction or cone biopsy. Main attention should be directed at early detection of dysplasia, at timely institution of follow-up programs and a possibly conservative therapeutic management.

Time-resolved fluorescence imaging of europium chelate label in immunohistochemistry and in situ hybridization

Fluorescent lanthanide chelates with long decay times allow the suppression of the fast decaying autofluorescence in biological specimens. This property makes lanthanide chelates attractive as labels for fluorescence microscopy. As a consequence of the suppression of the background fluorescence the sensitivity can be increased. We modified a standard epifluorescence microscope for time-resolved fluorescence imaging by adding a pulsed light source and a chopper in the narrow aperture plane. A cooled CCD-camera was used for detection and the images were digitally processed. A fluorescent europium chelate was conjugated to antisera and to streptavidin. These conjugates were used for the localization of tumor associated antigen C242 in the malignant mucosa of human colon, for the localization of type II collagen mRNA in developing human cartilaginary growth plates, and for the detection of HPV type specific gene sequences in the squamous epithelium of human cervix. The specific slowly decaying fluorescence of the europium label could be effectively separated from the fast decaying background fluorescence. It was possible to use the europium label at the cell and tissue level and the autofluorescence was effectively suppressed in in situ hybridization and immunohistochemical reactions in both frozen and formaldehyde-fixed, wax-embedded specimens.

Detection and typing of human papillomaviruses in cervical smears by an original application of the polymerase chain reaction

The detection and typing of human papillomaviruses on cervical smears were performed by means of a new application of the polymerase chain reaction allowing easier and faster detection of the amplification product. This application consisted of a combination of two series of amplifications and the use of primers labelled with biotin and with 125 iodine on a reporter group for the second amplification. The final amplification product was detected by counting the radioactivity after incubation of the media in avidin-coated tubes. This test was compared with conventional methods of detection by electrophoresis and Southern blot and its specificity was confirmed. The study of a series of 52 patients demonstrated a higher prevalence of type 16 in relation to type 6/11 and 18 and a correlation between the degree of dysplasia and the frequency of oncogenic types 16 and 18. This new application could facilitate studies of the prevalence of HPV in large series of cervical smears.

In situ detection of HPV DNA in oral mucosal lesions. A comparison of two hybridization kits

The purpose of this study was to compare the sensitivity of ViraType in situ hybridization kit (Life Technologies, Inc. [LT] and PathoGene (Enzo Diagnostics, Inc. [ED]) in situ hybridization kit for human papillomavirus (HPV) DNA detection in oral tissue. Forty benign oral lesions histologically suspicious for HPV infection were analyzed. Specimens were hybridized with DNA probes specific for HPV types 6/11, 16/18, and 31/33/35 [LT] and HPV types 6/11, 16/18, and 31/33/51 [ED]. Positive hybridization reactions were seen for HPV DNA type 6/11 only. Hybridization occurred significantly more often (p less than 0.01, McNemar Exact Test) in LT probed specimens (20/40) than ED assayed sections (12/40). HPV DNA sequences were found in 100% condyloma acuminata (13/13), 100% verruca vulgaris (4/4), and 13% squamous papilloma (3/23) using the LT system. The ED probes yielded positive signals in 77% condyloma acuminata (10/13), 25% verruca vulgaris (1/4), and 4.4% squamous papilloma (1/23). A more intense hybridization signal was exhibited using the LT system. The results indicate that the LT probes and detection reagents are more sensitive for detecting HPV DNA in oral mucosal specimens.

Comparison of four non-radioactive and 35S-based methods for the detection of human papillomavirus DNA by in situ hybridization

Human papillomavirus DNA was detected in 40 condylomatous lesions of various sites (vulva, cervix, larynx, penis and anus) by in situ hybridization using 35S-labelled probes and four non-radioactive probes to compare the various sensitivities of these techniques on the same material (formalin-fixed and paraffin-embedded sections). Radioactive probes yielded 28 positive results out of 40 (70%). Sulphonated probes (HybriCyte kit) also gave 28 positive results with a fine pattern of hybridization grains and equal sensitivity to 35S-labelled probes. Biotinylated and digoxigenin-labelled probes gave analogous results (25 positive reactions with the PathoGene kit, 26 with the Viratype kit, and 25 with digoxigenin-labelled probes) but are slightly less sensitive than radiolabelled and sulphonated probes especially when the signal is weak.

Human papillomavirus (HPV) infections and their associations with oral disease

More than 65 distinct types of human papillomavirus (HPV) have been identified to date. Several of the HPV types have been proposed as etiologic agents of squamous cell carcinoma. In the oral cavity, HPVs have been found associated with several benign squamous cell proliferations. Evidence from histology and DNA hybridization studies suggests that HPV is also involved in oral carcinogenesis. It is apparent, however, that substantial amount of confusion exists in the diagnosis of oral HPV infections. The keratotic, papillary lesions in the oral cavity are usually small and easily overlooked. The gross appearance of these viral lesions is not distinct enough to be readily diagnosed by the clinicians. Degenerative changes found on oral mucosa frequently simulate koilocytosis. Thus, caution should be exercised to avoid overdiagnosis of HPV infection in the oral cavity. The present review summarizes the current evidence available on HPV infections in general and on oral HPV infections in particular. The diagnostic techniques available as well as the problems encountered in the distinction of these lesions are also discussed in short.

Detection of human papillomavirus DNA in genital lesions by using a modified commercially available in situ hybridization assay

A modified, commercially available DNA-DNA in situ hybridization test that uses biotinylated probes for the identification of human papillomavirus (HPV) DNA types 6/11, 16/18, and 31/33/35 was evaluated. HPV DNA was detected in 314 of 787 (40%) histologically abnormal genital biopsy specimens by using the ViraType in situ assay (Life Technologies, Gaithersburg, Md.), in which the hybridization time was increased from 2 to 16 h. Ninety percent of positive condyloma acuminata specimens contained HPV type 6/11 DNA. The prevalences of HPV DNA for cervical intraepithelial neoplasia I, II, and III lesions by this in situ hybridization test were 42, 54, and 55%, respectively. The combined prevalence of HPV type 16/18 and 31/33/35 DNAs increased with the severity of the lesion, while the prevalence of type 6/11 DNA decreased. HPV type 6/11 DNA was found only in 1 of 16 (6%) positive cervical intraepithelial neoplasia III specimens. HPV type 16/18 and 31/33/35 DNA was detected in 11 of 16 (69%) and 4 of 16 (25%) in situ hybridization-positive cervical intraepithelial neoplasia III specimens, respectively. Thus, the observation that certain "higher-risk" HPV genotypes are associated with upper-grade cervical precancer lesions was confirmed by this commercial hybridization system. In general, the assay was found to be well suited for use in the clinical laboratory. The ViraType in situ procedure modified for a longer hybridization time may be helpful in identifying lesions containing higher-risk HPV strains.