General primer-mediated polymerase chain reaction permits the detection of sequenced and still unsequenced human papillomavirus genotypes in cervical scrapes and carcinomas

Advances in human papillomavirus detection and molecular understanding in head and neck cancers: Implications for clinical management

Head and neck cancers (HNCs), primarily head and neck squamous cell carcinoma (HNSCC), are associated with high-risk human papillomavirus (HR HPV), notably HPV16 and HPV18. HPV status guides treatment and predicts outcomes, with distinct molecular pathways in HPV-driven HNSCC influencing survival rates. HNC incidence is rising globally, with regional variations reflecting diverse risk factors, including tobacco, alcohol, and HPV infection. Oropharyngeal cancers attributed to HPV have significantly increased, particularly in regions like the United States. The HPV16 genome, characterized by oncoproteins E6 and E7, disrupts crucial cell cycle regulators, including tumor protein p53 (TP53) and retinoblastoma (Rb), contributing to HNSCC pathogenesis. P16 immunohistochemistry (IHC) is a reliable surrogate marker for HPV16 positivity, while in situ hybridization and polymerase chain reaction (PCR) techniques, notably reverse transcription-quantitative PCR (RT-qPCR), offer sensitive HPV detection. Liquid-based RT-qPCR, especially in saliva, shows promise for noninvasive HPV detection, offering simplicity, cost-effectiveness, and patient compliance. These molecular advancements enhance diagnostic accuracy, guide treatment decisions, and improve patient outcomes in HNC management. In conclusion, advances in HPV detection and molecular understanding have significant clinical management implications. Integrating these advancements into routine practice could ultimately improve patient outcomes.

Correlation between cervical HPV DNA detection and HPV16 seroreactivity measured with L1-only and L1+L2 viral capsid antigens

Introduction. Persistent human papillomavirus (HPV) type 16 infection is the main causal agent of cervical cancer. Most HPV infections clear spontaneously within 1-2 years. Although not all infected women develop detectable HPV antibodies, about 60-70 % seroconvert and retain their antibodies at low levels.Aim. We investigated if cervical HPV16 DNA positivity was associated with HPV16 seroreactivity measured with two different antigen formulations. We assessed if associations were influenced by co-infection with other HPV types and HPV16 viral load.Methodology. We used baseline data for women participating in the Ludwig-McGill cohort, a longitudinal investigation of the natural history of HPV infection and cervical neoplasia. The study enrolled 2462 Brazilian women from 1993 to 1997 (pre-vaccination). ELISA assays were based on L1-only or L1+L2 virus-like particles (VLPs). Seroreactivity was expressed as normalized absorbance ratios. HPV genotyping and viral load were evaluated by PCR protocols. Pearson's r was used to measure correlations between interval-scaled variables. Serological accuracy in HPV16 DNA detection was assessed using receiver operating characteristic (ROC) curves. We analysed the association between HPV DNA positivity and HPV16 seroreactivity by linear regression.Results. Correlations between L1+L2 and L1-only VLPs for detection of HPV16 were poor (r=0.43 and 0.44 for dilutions 1 : 10 and 1 : 50, respectively). The protocol with the best accuracy was L1+L2 VLPs at serum dilution 1 : 10 (ROC area=0.73, 95 % CI: 0.65-0.85). HPV16 DNA positivity was correlated with HPV16 seroreactivity and was not influenced by co-infection or viral load. To a lesser degree, HPV16 seroreactivity was correlated with infection by other Alpha-9 papillomavirus species.Conclusion. HPV16 DNA positivity and HPV16 seroreactivity are strongly correlated. L1+L2 VLPs perform better than L1-only VLPs for detecting IgG antibodies to HPV16 in women infected with HPV16 or other Alpha-9 HPV species. This study advances our understanding of humoral immune responses against HPV16 by providing insights about the influence of VLP antigen composition to measure humoral immune response against naturally acquired HPV infection.

Human papillomavirus type distribution and HPV16 intratype diversity in southern Brazil in women with and without cervical lesions

BACKGROUND

Increasing evidence suggests that human papillomavirus (HPV) intratype variants (specific lineages and sublineages) are associated with pathogenesis and progression from HPV infection to persistence and the development of cervical cancer.

OBJECTIVES

This study aimed to verify the prevalence of HPV infection and distribution of HPV types and HPV16 variants in southern Brazil in women with normal cytology or intraepithelial lesions.

METHODS

HPV typing was determined by L1 gene sequencing. To identify HPV16 variants, the LCR and E6 regions were sequenced, and characteristic single nucleotide variants were identified.

FINDINGS

A total of 445 samples were studied, with 355 from cervical scrapes and 90 from cervical biopsies. HPV was detected in 24% and 91% of these samples, respectively. The most prevalent HPV types observed were 16 (cervical, 24%; biopsies, 57%) and 58 (cervical, 12%; biopsies, 12%). Seventy-five percent of the HPV16-positive samples were classified into lineages, with 88% defined as lineage A, 10% as lineage D, and 2% as lineage B.

MAIN CONCLUSIONS

This study identified a high frequency of European and North American HPV16 lineages, consistent with the genetic background of the human population in southern Brazil.

Complex of molecular genetic and immunohistochemical methods for detection of human papillomavirus in the bladder cancer epithelium

A battery of tests for detection human papillomavirus DNA, mRNA corresponding to viral oncogenes, and viral oncoprotein E7 in cancer bladder urothelium was piloted in 35 samples of bladder cancer. DNA of human papillomavirus type 16 (causes cervical cancer) was found in 16 (46%) samples; E6/E7 oncogene transcript and E7 oncoprotein of human papillomavirus type 16 were detected in 10 and 7 human papillomavirus DNA-positive samples, respectively. These findings attest to association of bladder cancer with human papillomavirus in Russia.

Prevalence of herpes simplex virus type 2 and risk factors associated with this infection in women in southern Brazil

SUMMARY

The herpes simplex virus type 2 (HVS-2) is the most prevalent infection worldwide. It is a cofactor in the acquisition of human immunodeficiency virus (HIV) and the persistence of human papillomavirus (HPV). This study evaluated the prevalence of HSV-2, using the polymerase chain reaction (PCR), and associated factors in patients treated at the Federal University of Rio Grande (FURG) and Basic Health Units (BHU) in Rio Grande, Brazil. The observed prevalence of HSV-2 was 15.6%. Among the 302 women studied, 158 had received assistance in BHU and 144 were treated at FURG. The prevalence of HSV-2 in these groups was 10.8% and 20.8%, respectively, RR 1.9 and p = 0.012. Knowledge about the Pap smear, and the presence of lesions showed no association with HSV-2 infection. Multivariate analysis showed that the variable that most influenced the risk of HSV-2 infection was the presence of HIV infection, with a relative risk of 1.9 and p = 0.04. Discussion: Genital ulcers are an important entry point for HIV, and condom use is an important strategy to reduce transmission of HIV and HSV-2.

Human papillomavirus type 16 viral load measurement as a predictor of infection clearance

Viral load measurements may predict whether human papillomavirus (HPV) type 16 infections may become persistent and eventually lead to cervical lesions. Today, multiple PCR methods exist to estimate viral load. We tested three protocols to investigate viral load as a predictor of HPV clearance. We measured viral load in 418 HPV16-positive cervical smears from 224 women participating in the Ludwig-McGill Cohort Study by low-stringency PCR (LS-PCR) using consensus L1 primers targeting over 40 known HPV types, and quantitative real-time PCR (qRT-PCR) targeting the HPV16 E6 and L1 genes. HPV16 clearance was determined by MY09/11 and PGMY PCR testing on repeated smears collected over 5 years. Correlation between viral load measurements by qRT-PCR (E6 versus L1) was excellent (Spearman's rank correlation, ρ = 0.88), but decreased for L1 qRT-PCR versus LS-PCR (ρ = 0.61). Viral load by LS-PCR was higher for HPV16 and related types independently of other concurrent HPV infections. Median duration of infection was longer for smears with high copy number by all three PCR protocols (log rank P<0.05). Viral load is inversely related to HPV16 clearance independently of concurrent HPV infections and PCR protocol.

Multiple-type human papillomavirus infection in younger uncircumcised men

A cohort of 388 young men enrolled for military service in the Danish army was established and the participants underwent a clinical examination with human papillomavirus (HPV) testing. In addition, a questionnaire containing questions regarding sociodemographic variables, sexual habits and lifestyle factors was completed. The prevalence of HPV was 33.4% in this cohort of uncircumcised men aged 18-29 years. Multiple HPV types were prevalent with one-third of the HPV-positive men being positive for more than one HPV type. Number of recent sexual partners and infrequent condom use were strong risk factors, particularly in men having multiple HPV types. Our findings re-emphasize the importance of sexual transmission and also point to a role of factors that may be related to individual susceptibility as genital warts, alcohol intake and, to a lesser extent, smoking were strongly associated with having multiple HPV types.

Human papillomavirus infection and reinfection in adult women: the role of sexual activity and natural immunity

There is a paucity of data on whether or not women can be reinfected with human papillomavirus (HPV) types to which they were exposed to earlier in life and on the role of natural immunity. The observation of HPV infection at older ages may be explained by the reactivation of a latent infection or new exposure from sexual activity. Our objective was to analyze the association between reinfection and sexual activity. We analyzed data from 2,462 women enrolled in the Ludwig-McGill cohort and followed every 4 to 6 months for up to 10 years. We performed HPV typing and viral load measurements via PCR and determined HPV-16 seroreactivity at enrollment. Incidence of infection and reinfection were estimated for individual types. Adjusted relative risks (RR) for the association between infection/reinfection and new sexual partners were calculated using Cox regression. Rates of initial infection and reinfection postclearance were statistically comparable. RRs of initial infection or reinfection were consistently associated with new sexual partners [2.4 (95% confidence intervals; 95% CI, 2.0-3.1) for first infection, 3.7 (1.1-13.8) for reinfection with the same type, and 2.3 (1.5-3.7) for reinfection with a different type]. Reinfection in older women was also associated with new sexual partners (RR, 2.8; 95% CI, 1.4-5.3) as were new infections with HPV-16 among women with serologic evidence of prior HPV-16 exposure (RR, 3.0; 95% CI, 1.6-5.3). Viral loads at initial infection and at reinfection were comparable. HPV infection and reinfection were strongly associated with sexual activity. This study suggests that natural immunity does not play a role in controlling the extent of reinfections.

Diagnostic role of p16/INK4A protein in Human Papillomavirus (HPV) induced cervical dysplasia

The p16/INK4A protein is a cellular regulatory polypeptide over-expressed in the presence of high levels of the Human Papillomavirus (HPV) coded E7 protein. This review outlines the use of p16 antigen staining in cervical biopsies as well as in PAP smears summarizing the corresponding literature and commenting the authors’ own experience. The p16 antigen is a reliable marker for dysplastic cells in CINII/CINIII (HSIL) lesions as viewed in cervical biopsies. When PAP smears were examined at large scale screening for p16 antigenreactive and atypical cells, considerable variations could be found especially in ASCUS graded lesions. Therefore, the presence of p16-reactive atypical cells in PAP smears should be interpreted together with the cytological signs of dysplasia, such as the altered N/C ratio. In addition, women revealing p16-positive ASCUS/LSIL specimens should be examined for the presence of HPV DNA. Detection of HPV DNA alone, i.e. in the absence of cytological screening has a low predictive value, since the clearance of HPV may occur even in the absence of morphological alterations. Combined cytological as well as molecular follow up contributes to the efficiency of diagnostic and increases the probability of correct interpretation of the pre-cancerous lesions by non-invasive techniques.

Age-specific prevalence of infection with human papillomavirus in females: a global review

PURPOSE

Global data on age-specific prevalence of human papillomavirus (HPV) infection overall, and for high-risk HPV types 16 and 18, are essential for the future implementation of HPV prophylactic vaccines for cervical cancer prevention.

METHODS

A systematic review of peer-reviewed publications was conducted to summarize worldwide data on genital HPV-DNA prevalence in women. Studies with clear descriptions of polymerase chain reaction or hybrid capture detection assays were included.

RESULTS

A total of 346,160 women were included in 375 studies. Of 134 studies with age-stratified HPV prevalence data (116 low sexual risk populations, 18 high sexual risk populations), over 50% were from Europe and the Middle East (38%) and North America (19%), with smaller proportions from Asia and Australia (21%), Central and South America (11%), and Africa (10%). Across all geographical regions, data on HPV prevalence were generally limited to women over 18 years of age. Consistently across studies, HPV infection prevalence decreased with increasing age from a peak prevalence in younger women (< or =25 years of age). In middle-aged women (35-50 years), maximum HPV prevalence differed across geographical regions: Africa (approximately 20%), Asia/Australia (approximately 15%), Central and South America (approximately 20%), North America (approximately 20%), Southern Europe/Middle East (approximately 15%), and Northern Europe (approximately 15%). Inconsistent trends in HPV prevalence by age were noted in older women, with a decrease or plateau of HPV prevalence in older ages in most studies, whereas others showed an increase of HPV prevalence in older ages. Similar trends of HPV 16 and/or 18 prevalence by age were noted among 12 populations with available data.

DISCUSSION

Genital HPV infection in women is predominantly acquired in adolescence, and peak prevalence in middle-aged women appears to differ across geographical regions. Worldwide variations in HPV prevalence across age appear to largely reflect differences in sexual behavior across geographical regions. Further studies of HPV prevalence in adolescents are needed for all geographic regions.

Quality assurance of genotyping array for detection and typing of human papillomavirus

The aim of this study was to evaluate the sensitivity, specificity, reliability and reproducibility of the EasyChip HPV blot for human papillomavirus (HPV) genotyping. Type-specific sensitivity and specificity for 39 types of HPV (HPV 6, 11, 16, 18, 26, 31, 32, 33, 35, 37, 39, 42, 43, 44, 45, 51, 52, 53, 54, 55, 56, 58, 59, 61, 62, 66, 67, 68, 69, 70, 72, 74, 82, CP8061, CP8304, L1AE5, MM4, MM7 and MM8) were examined. The operating environment, reliability, reproducibility and blot interpretation were assessed by a quality assurance system. Each batch experiment contained samples from 89 cervical specimens and 7 extrinsic controls. Caski, HeLa and Jurkat cells, male human blood cell DNA and sterile water were used to assess reliability. Furthermore, pairs of sibling controls were used to assess reproducibility. The overall sensitivity of HPV detection was 1-50 copies of HPV genome equivalent. There was no cross-reactivity with amplicons of other HPV genotypes. One hundred batch experiments demonstrated that the reliability was excellent. The intra-batch and inter-batch reproducibility was 98 and 97%, respectively. It was concluded that the EasyChip HPV blot is a highly sensitive, reliable and reproducible tool for detection and identification of HPV genotypes.

Lack of agreement between cervicography and cytology and the effect of human papillomavirus infection and viral load

OBJECTIVE

Cohort studies of the natural history of human papillomavirus (HPV) infection and cervical squamous intraepithelial lesions with repeated screening allow the comparison of different macroscopic and microscopic diagnostic methods.

MATERIALS AND METHODS

Concurrent visual inspection using cervicography and conventional Pap cytology tests were performed during multiple visits in a cohort of women attending a maternal and child health clinic in São Paulo, Brazil. HPV infection status at the same visits was determined by polymerase chain reaction followed by typing with specific oligonucleotide probing and viral load quantification. Information on reproductive health and hygiene habits was also collected at each visit.

RESULTS

Overall agreement between cervicography and cytology was low (kappa = 0.046), which increased only slightly when high oncogenic-risk HPV types (kappa = 0.120) or high viral burden (>100 copies/cell) (kappa = 0.170) was present. Analysis of reproductive health and hygiene habits revealed somewhat different risk factors for cervical lesions detected by these tests. However, presence of oncogenic HPV DNA (odds ratio = 36.0, 95% CI = 16.6-77.8) and high viral burden (odds ratio = 67.34; 95% CI = 27.1-167.0) were strongly associated with lesions detected by cytology but not by cervicography.

CONCLUSIONS

Although changes in the cervix (because of age, gravidity, or hormonal effects) may influence the performance of morphology-based screening tests, the lack of agreement and the different degrees of association with HPV infection measures indicate that a visual inspection method such as cervicography may detect different cervical abnormalities relative to cytology.

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.

Sexually transmitted Human Papillomavirus type variations resulting in high grade cervical dysplasia in North-East North Dakota and North-West Minnesota

Background

A review of Pap smear diagnoses from a reference laboratory in Grand Forks, North Dakota over a 3-year period (07/00 to 10/03) revealed a two-fold higher rate of high grade squamous intraepithelial lesion in a community in northwest Minnesota (Roseau, 0.486%) than in northeast North Dakota (Grand Forks, 0.249%), in spite of both having similar rates of low-grade squamous intraepithelial lesion (1.33% vs.1.30% respectively)

Objectives

To identify the different types of HPV present in patient populations showing high-grade dysplasia in Grand Forks, ND and Roseau, MN.

Study design

Formaldehyde-fixed paraffin-embedded cervical tissue samples were analyzed using polymerase chain reaction (PCR) to detect the presence of HPV type 16, 18 and 31.

Results

Our studies showed that 41 % of samples from Roseau were triply infected with HPV serotypes 16, 18 and 31 in comparison to 12 % from Grand Forks.

Conclusion

Due to the small sample size we were unable to prove the study to be statistically significant. However, our results suggest that the presence of HPV 16, 18 and 31 in triply infected samples may be the cause of the higher percentage of high-grade dysplasia in Roseau, MN when compared to Grand Forks, ND.

Comparison of polymerase chain reaction and catalyzed signal amplification in situ hybridization methods for human papillomavirus detection in paraffin-embedded cervical preneoplastic and neoplastic lesions

BACKGROUND

Two molecular methods for HPV genotyping in formalin-fixed, paraffin-embedded tissue were evaluated: in house polymerase chain reaction assay (PCR) with consensus and type-specific primers and a novel procedure of in situ hybridization-a catalyzed signal amplification system (CSA-ISH, Genpoint, DAKO, Glostrup, Denmark). The number of HPV positive cases and detected viral types were compared in cervical biopsies and cone specimens according to histopathological diagnosis. Primer efficiency in detecting various types of HPV by PCR method was evaluated.

METHODS

DNA samples (101) were used as a template to amplify with three pairs of consensus (MY09/11, GP5+/6 +, CPI/IIG) and four type-specific HPV primers (HPV-6/11, 18, 16 and 33). The according histological tissue sections were analyzed with CSA-ISH method, using commercial HPV biotinylated probes HPV-6/11, 16/18 and 31/33/51.

RESULTS

The degree of concordance for PCR and CSA-ISH was 64.4%. In 63 of 101 samples (62.4%), HPV was detected by PCR, while only 35 (34.7%) were positive using CSA-ISH. CSA-ISH found lower percentages for all HPV types, except HPV-6/11. A lower percentage of positive results in all high-grade lesions was detected by CSA-ISH. Multiple infections were detected by PCR in only one sample and in three samples by CSA-ISH. Detection with My09/11 primers followed by Gp5+/6+ primers, in nested reaction, gave the highest number of positive results: 58 of 63 (92%). None of the samples diagnosed as condylomata planum or CIN I was positive for HPV-6/11 (low risk type), which was detected exclusively in condylomata acuminatum group.

CONCLUSIONS

A significantly higher number of positive samples was detected with PCR than with CSA-ISH method. CSA-ISH method should be improved, especially in detecting HPV in high-grade lesions. CSA-ISH may be more accurate in detection of multiple infections. GP5+/6+ in nested reaction after MY09/11 detected the highest number of positive results. Samples diagnosed as benign lesions positive on HPV-X must be monitored as possible candidates for progression. CIN I lesions, which were HPV negative, probably will not progress. This finding may be important in planning therapy and avoiding unnecessary treatment.

Acquisition and Persistence of Human Papillomavirus Infection in Younger Men: A Prospective Follow-up Study among Danish Soldiers

No data is yet available on incidence or persistence of human papillomavirus (HPV) infection in men. We enrolled 374 younger male conscripts (18-29 years) in a prospective study, and they were examined twice with an interval of 6 to 8 months. Data collection included a questionnaire and a sample of cells from the penis for HPV detection using PCR. In addition, the presence of Chlamydia trachomatis DNA was assessed in urine samples by means of PCR. The HPV prevalence at the first and second examinations was 33.8% and 31.9%, respectively. The acquisition rate of HPV (overall) during follow-up was 13.8%, and nearly one fourth of the participants were HPV positive at both examinations. Number of sex partners during follow-up was the most important risk factor for acquiring HPV (odds ratio, 17.2; 95% confidence interval, 4.6-64.7, for > or = 3 partners versus < or = 1 partner). In contrast, acquisition of a new HPV type in initially HPV-positive men was strongly related to having multiple HPV types at enrollment (OR, 4.1; 95% confidence interval, 1.4-12.3). This was also the most important risk factor for HPV persistence together with current smoking and having a high-risk HPV type at enrollment. This is the first study to assess risk factors for acquisition and persistence of HPV. The sexually transmitted nature of the infection is confirmed, and the data point to an important role of having multiple HPV types for persistence.

Semiquantitative analysis of human papillomavirus DNA in cervical intraepithelial neoplasia by a differential polymerase chain reaction

A differential polymerase chain reaction (PCR), which takes account of both the human papillomavirus (HPV) type and the amount of viral DNA, was applied to 100 cervical intraepithelial neoplasias (CIN) in order to improve the characterisation of the lesions. One hundred women with cytological smears suggestive of CIN I-III and a colposcopically guided punch biopsy were studied. DNA was phenol-extracted and a consensus PCR with L1 primers and a type-specific PCR for HPV-16 and-18 E6 were performed in parallel. The different sensitivity of the PCR methods allowed a semiquantitative analysis of viral DNA. HPV analysis was possible in all 100 very small cervical punch biopsies. Of the lesions 79% were HPVpositive. The percentage of HPV-16-positive lesions increased significantly (P < 0.001) with the degree of severity of CIN (CIN I: 46%, CIN II: 63%, CIN III: 85%). The percentage of CIN with a high viral load increased also with the grade of CIN (CIN I: 8%, CIN II: 33%, CIN III: 44%). Cytologically positive lesions (Pap IIID or IVa) had significantly more frequently (p < 0.02) a high viral load: 39% vs. 10% of cytologically false negative lesions. In conclusion, type-specific PCR had a very high sensitivity in the detection of HPV-DNA also in cytologically false negative CIN. The addition of the less sensitive consensusPCR allowed a semiquantitative analysis of the viral copy number. The higher amount of viral DNA in cytologically positive lesions, which may correspond to a higher rate of proliferation, reflects a possible role of the viral load in the progression of CIN. In clinical practice, differential HPVPCR could help to improve the management of CIN.

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

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

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.

Viral load as a predictor of the risk of cervical intraepithelial neoplasia

HPV infections are believed to be a necessary cause of cervical cancer. Viral burden, as a surrogate indicator for persistence, may help predict risk of subsequent SIL. We used results of HPV test and cytology data repeated every 4-6 months in 2,081 women participating in a longitudinal study of the natural history of HPV infection and cervical neoplasia in São Paulo, Brazil. Using the MY09/11 PCR protocol, 473 women were positive for HPV DNA during the first 2 visits. We retested all positive specimens by a quantitative, low-stringency PCR method to measure viral burden in cervical cells. Mean viral loads and 95% CIs were calculated using log-transformed data. RRs and 95% CIs of incident SIL were calculated by proportional hazards models, adjusting for age and HPV oncogenicity. The risk of incident lesions increased with viral load at enrollment. The mean number of viral copies/cell at enrollment was 2.6 for women with no incident lesions and increased (trend p = 0.003) to 15.1 for women developing 3 or more SIL events over 6 years of follow-up. Compared to those with <1 copy per cell in specimens tested during the first 2 visits, RRs for incident SIL increased from 1.9 (95% CI 0.8-4.2) for those with 1-10 copies/cell to 4.5 (95% CI 1.9-10.7) for those with >1,000 copies/cell. The equivalent RR of HSIL for >1,000 copies/cell was 2.6 (95% CI 0.5-13.2). Viral burden appears to have an independent effect on SIL incidence. Measurement of viral load, as a surrogate for HPV persistence, may identify women at risk of developing cervical cancer precursors.

Prevalence of human papillomavirus in cervical cancer: a multicenter study in China

A large-scale epidemiologic survey on the prevalence of different types of human papillomavirus (HPV) in cervical cancer in China is indicated because of the implications for the development of diagnostic probes and vaccines against cervical cancer. A total of 809 cervical cancer specimens were collected from 5 regions in China including Shanghai, Guangzhou, Sichuan, Beijing and Hong Kong. HPV DNA was detected in 83.7% of the specimens. HPV-16 was present in 79.6%, HPV-18 in 7.5%, HPV-52 in 2.6% and HPV-58 in 3.8% of all HPV-positive specimens. The prevalences of HPV-16 and HPV-18 in Hong Kong were 61.7 and 14.8%, respectively, representing a lower HPV-16 and a higher HPV-18 proportion compared with the other regions. HPV-16 remained the most common HPV infection in both squamous cell carcinoma (SCC) and adenocarcinoma (AC). The proportion of HPV-18 infection was significantly higher in AC than in SCC.

Sexual and non-sexual transmission of human papillomavirus

Benign tumors and lesions of the anogenital tract are caused by human papillomaviruses (HPVs). They are also major risk factors for cervical cancer. Introduction of the polymerase chain reaction (PCR) revealed that HPV infections are much more common among young asymptomatic women than it had been previously suspected. The side-specificity of genital HPVs led to the assumption that HPVs were primarily transmitted by sexual contact. However, since HPVs have been detected in virgins, infants/children and juvenile laryngeal papillomatosis was shown to be caused by these viruses, it became acknowledged that HPVs may be transmitted by other--non-sexual--routes as well. The evidence for sexual and different non-sexual routes of transmission of HPVs will be reviewed here.

Risk factors for genital HPV DNA in men resemble those found in women: a study of male attendees at a Danish STD clinic

OBJECTIVES

Genital infection with certain types of human papillomavirus (HPV) is the most important risk factor for cervical cancer. The male sexual partner is supposed to be the vector of the infection. However, the knowledge of risk factors for genital HPV DNA in men is limited. The objective of this paper is to study the risk factors for HPV infection in men and to compare them with those found in women, including the study of whether there are different risk profiles for oncogenic and non-oncogenic HPV types.

METHODS

From a sexually transmitted diseases (STD) clinic in Denmark, 216 men were consecutively included. A personal interview was done and material for genital HPV DNA detection was obtained with swabs. HPV DNA was detected by polymerase chain reaction (PCR). Odds ratios (OR) for HPV as well as for oncogenic and non-oncogenic types separately were computed with a 95% confidence interval (CI) by means of unconditional multiple logistic regresssion.

RESULTS

The most important predictors of any HPV were lifetime number of sex partners (OR = 4.3; 95% CI 1.4 to 13.1 for 25-39 v 1-9 partners), young age, and being uncircumcised. The most important risk factor for oncogenic HPV types was lifetime number of partners, whereas number of partners in the past year and ever having genital warts were risk factors for the non-oncogenic HPV types. Young age predicted risk of both oncogenic and non-oncogenic HPV types.

CONCLUSIONS

Most risk factors for HPV DNA detection in men resemble those found in women. As in women, the risk factor profile for the oncogenic HPV types was different from that of the non-oncogenic HPV types.

Persistent human papillomavirus infection and smoking increase risk of failure of treatment of cervical intraepithelial neoplasia (CIN)

Women with abnormal smears have an increased risk of developing cervical cancer. During the 8 years following conservative treatment of cervical intraepithelial neoplasia (CIN), their risk of invasive cervical cancer is about 5 times greater than that of the general population. Human papillomavirus (HPV) has been associated with the natural history of both CIN and cervical cancer. To date, there have been no published reports on the predictive value of HPV testing in the treatment outcome of CIN. A prospective, multi-center, cohort study was conducted on women in the Northwest of England who were attending for treatment of CIN. They were asked to complete a questionnaire, which included a detailed smoking history. Pre- and post-treatment HPV testing was performed on cervical biopsies and cervical swab, being taken with the first follow-up smear at 6 months. A nested case-control analysis was performed, cases being defined as women who developed CIN within the 2 years of treatment and controls being sampled from those who did not experience treatment failure within 2 years. Multiple conditional logistic regression is used to study the factors associated with treatment failure of CIN. The cohort included 958 women of whom 77 (8%) experienced treatment failure (cases). Two controls were matched to each case (154). Smoking status was significantly associated with CIN treatment failure(p= 0.0013). Current smokers had a 3-fold increased risk of treatment failure of CIN as compared to non-smokers (95% CI 1.65 to 5.91). Five hundred twenty-five women underwent HPV sampling following treatment, of whom 47 (8.9%) developed further CIN. Post-treatment positive HPV testing was found to be strongly associated with treatment failure of CIN (OR 23.3; 95% CI 3.15-172.1). In 11/45 cases with negative smear at first follow-up, the HPV test was positive. The combination of both HPV and cytology in the first follow-up visit predicted treatment failure in 72% of the cases. Cigarette smoking is a factor, which, independently of HPV infection, influences the treatment outcome of CIN. Smokers and those who are HPV positive during follow-up appear to require longer, more intensive follow-up. HPV testing requires careful consideration as part of routine follow-up protocol following treatment of CIN.

GP5+/6+ PCR followed by reverse line blot analysis enables rapid and high-throughput identification of human papillomavirus genotypes

In this study, we developed a simple and fast typing procedure for 37 mucosotropic human papillomavirus (HPV) types using a nonradioactive reverse line blotting (RLB) procedure for general primer (GP5+/6+) PCR products. This system has the advantages not only that in a simple format, up to 42 PCR products can be simultaneously typed per membrane per day, but also that after stripping, the membranes can be easily rehybridized at least 15 times without a loss of signal. RLB appeared highly specific, and its sensitivity was identical to that of conventional typing performed with type-specific oligonucleotide probes in an enzyme immunoassay (EIA). The performance of RLB typing was evaluated with samples of HPV-positive cervical scrapings (n = 196) and biopsies of cervical premalignant lesions (n = 100). The distribution of HPV genotypes detected in these samples was in line with the distribution expected on the basis of literature data. In addition, RLB and EIA typing procedures were compared for the typing of high-risk HPV types in GP5+/6+ PCR products of 210 cervical scrapings from high-risk HPV-positive women who participated in a population-based screening program. The typing procedures had an excellent overall agreement rate of 96.5% (kappa value, 0.77). RLB was successful in detecting multiple HPV infections as well as single infections. In conclusion, the GP5+/6+ PCR-RLB procedure appeared to be a reliable and simple approach that may be of great value for large epidemiological studies, population-based cervical cancer screening programs, and vaccination trials that require high-throughput HPV typing.

Prevalence, distribution, and viral load of human papillomavirus 16 DNA in tonsillar carcinomas

BACKGROUND

Oncogenic human papillomaviruses (HPV) DNA have repeatedly been observed in many head and neck carcinomas (HNSCCs), and HPV infections are currently considered a possible factor in the etiology of these tumors. However, the reported prevalences of HPV-DNA in HNSCC are variable. In the current study the authors used highly sensitive polymerase chain reactions (PCRs) to analyze the occurrence of viral sequences in 98 carefully stratified HNSCCs. The authors determined the load and localization of HPV DNA in a subset of tonsillar carcinomas and their metastases.

METHODS

Nested PCR and an HPV16 specific single step PCR were used to screen 98 HNSCCs for HPV DNA for genital- and Epidermodysplasia verruciformis (EV)-associated HPVs. Typing was performed by direct sequencing and/or sequencing of cloned amplimers. In two patients HPV16 subtypes in tonsillar carcinomas and their metastases were compared by amplification and sequencing of the long control region of the virus. In a subset of HPV16 positive tonsillar carcinomas and their metastases, localization and viral load were determined using laser assisted microdissection and real time fluorescent PCR, respectively.

RESULTS

Altogether 25 HNSCCs (26%) were found to be HPV positive. Stratified according to the tumor localization, the frequency of HPV positive lesions was 18% in the oral cavity, 45% for oropharynx, 25% for hypopharynx, 8% for nasopharynx, and 7% for larynx. The highest HPV DNA prevalence (58%) was found in tonsillar carcinomas. The high risk HPV type 16 was found in 84% of positive HNSCCs, in 14% of which EV-associated HPVs were detected. Human papillomavirus sequences were detected in 64% of biopsies with normal mucosa from 11 patients with positive carcinomas. As a control group, 14 tumor free tonsils were analyzed. In none of these specimens were HPV sequences detected. Viral long transcriptional control region sequences in homologous metastases were identical with those in primary tumors and the load values in both locations were roughly comparable. Viral loads differed substantially in different areas of one tumor. Statistical evaluation of data related to clinicopathologic parameters showed a significant linkage of HPV with tonsillar carcinomas compared to other locations. Furthermore, a significant correlation of HPV status of tonsillar carcinomas with tumor grading and alcohol consumption was found.

CONCLUSIONS

Our study shows a preferential association of HPV-DNA with tonsillar carcinomas. The data support the view of HPV negative and positive tonsillar carcinomas being different tumor entities and conventional cancer risk factors being of less importance in HPV-infected individuals. The HPV genome is located in the cancer cells, whereas the infection of normal mucosa is a rare event. Data on quantification of HPV16 in tonsillar tumors and their metastases showed mean viral loads comparable to other HPV associated malignancies.

The relationship of human papillomavirus (HPV) detection to pap smear classification of cervical-scraped cells in asymptomatic women in northeast Thailand

OBJECTIVE

To correlate the detection of human papillomavirus (HPV) with the Pap smear classification of cervical-scraped cells from asymptomatic women living in northeast Thailand.

METHODS

A total of 260 asymptomatic women attending the Obstetrics and Gynecology's Outpatient Clinic, Srinagarind Hospital, Thailand, were interviewed for risk factors and cervical scrapes were taken. The cells were examined by Pap smear for cytological changes and by PCR for HPV DNAs--nononcogenic (HPVs 6 and 11) and oncogenic (HPVs 16, 18 and 33) types. Cervical biopsies were taken from women with abnormal Pap smears for histological examination.

RESULTS

Of the 260 cervical smear samples, the cervical cells were classified as normal and abnormal in 174 and 86, respectively. Twenty-three percent of all samples were positive for overall HPV DNA. HPV DNAs (mostly HPVs 6 and 11) were detected in 21% of normal cells, and the higher detection rate (27%) for HPV DNA in abnormal cells gradually increased in severity from 16% in Class 3 to 35 and 60% in Classes 4 and 5, respectively. Histologically 46, 90 and 100% of HPV detection was associated with CIS, SCC and adenocarcinoma, respectively. Almost all of the HPV DNAs detected were types 16, 18 or 33. There was no significant association between HPV infection and reproduction history, sexual behavior and demographic variables.

CONCLUSION

We speculated that an abnormal Pap smear and the detection of an oncogenic type HPV may indicate the presence of neoplastic cells in asymptomatic woman who might be at risk for the development of cervical cancer.

Human papillomavirus infection in Danish female sex workers. Decreasing prevalence with age despite continuously high sexual activity

BACKGROUND

The prevalence of the human papillomavirus (HPV) has been found to decrease with age, but whether this applies to all populations is not clear. Knowledge about the generalizability of this age dependency is important to understand the natural history of the infection, but may also have implications in relation to the use of HPV testing in cervical cancer screening.

GOAL

To study the prevalence and risk factors for HPV infection in a selected population of female sex workers and to compare the results with persons with different sexual habits from two other populations in the same geographic area.

STUDY DESIGN

A case-control study among 188 female sex workers from Copenhagen. Data were obtained by personal interviews. Cervical material was collected by a self-administered lavage kit, and HPV testing was done by means of GP5+/6+ primers based on HPV, polymerase chain reaction, enzyme immunoassay.

RESULTS

Among sex workers, age was the most important risk factor for HPV infection. Number of private sex partners in the last 4 months was also a significant risk factor, and a protective effect of condom use was indicated.

CONCLUSION

The HPV prevalence is declining in sex workers with age despite continuously high sexual activity, most likely indicating that an immune response is acquired over time.

"High risk" HPV types are frequently detected in potentially malignant and malignant oral lesions, but not in normal oral mucosa

Studies on the involvement of the human papillomavirus (HPV) in initiation and progression of oral neoplasia have generated conflicting results. The observed discrepancy is attributable mainly to the varying sensitivity of the applied methodologies and to epidemiologic factors of the examined patient groups. To evaluate the role of HPV in oral carcinogenesis, we analyzed 53 potentially neoplastic and neoplastic oral lesions consisting of 29 cases of hyperplasia, 5 cases of dysplasia, and 19 cases of squamous cell carcinomas, as well as 16 oral specimens derived from healthy individuals. A highly sensitive nested polymerase chain reaction (PCR) assay was used, along with type-specific PCR, restriction fragment length polymorphism analysis, dot blotting, and nonisotopic in situ hybridization. Nested PCR revealed the presence of HPV DNA in 48 of the 53 (91%) pathologic samples analyzed, whereas none (0%) of the normal specimens was found to be infected. Positivity for HPV was independent of histology and the smoking habits of the analyzed group of patients. At least one "high risk" type, such as HPV 16, 18, and 33, was detected by type-specific PCR in 47 (98%) infected specimens, whereas only 1 (2%) squamous cell carcinoma was solely infected by a "low risk" type (HPV 6). HPV 16 was the prevailing viral type, being present in 71% of infected cases. Single HPV 16 and HPV 18 infections were confirmed by restriction fragment length polymorphism. HPV 58 was detected by dot blotting in three hyperplastic lesions. HPV positivity and genotyping were further confirmed, and the physical status of this virus was evaluated by nonisotopic in situ hybridization. Diffuse and punctate signals, indicative of the episomal and integrative pattern of HPV infection, were observed for low- and high-risk types, respectively. Our findings are suggestive of an early involvement of high-risk HPV types in oral carcinogenesis.

Detection of human papilloma virus (HPV) genomes by the primed in situ (PRINS) labelling technique

Primed in situ Labelling, a technique based on primer mediated DNA synthesis, has become a useful tool in cytogenetics, especially for chromosome mapping, banding and the investigation of sequence organization in fresh metaphase preparations. Its application in the routine surgical pathology laboratory has been hampered by the fact that the technique did not work on paraffin-embedded, formalin-fixed tissue. We investigated cervical biopsies (n = 20) with morphological signs of HPV infection and found that the PRINS method is at least as sensitive as a classical in situ hybridization assay for detecting HPV DNA in paraffin-embedded, formalin-fixed tissue. In all investigated cases (n = 20), HPV DNA was found by both methods. The PRINS method was able to demonstrate HPV DNA not only in superficial koilocytotic squamous cells but also in non-koilocytotic cells in the deeper spinous cell layers, and even in some basal cells. We describe an economical protocol using conventional consensus HPV oligonucleotide DNA primers. The described method is rapid (approximately 3 hours) and easy to perform for screening and subtyping HPV infection in the routine surgical pathology laboratory.

Evidence for infection of the human embryo with adeno-associated virus in pregnancy

Previous reports have demonstrated the presence of DNA of the human helper virus-dependent adeno-associated parvovirus (AAV) in uterine tissue and curettage material from early miscarriage. To examine infection of embryonic tissue during pregnancy, amnion fluids were analysed for the presence of AAV. Using polymerase chain reaction, AAV DNA was detected in 64 out of 238 DNA samples extracted from amnion cells. DNA of helper viruses were found in 12% (papillomavirus) and 18% (cytomegalovirus) of the samples (double infections with AAV in eight and nine cases, respectively). Furthermore, infectious AAV virions were found in 13 out of 43 AAV DNA-containing samples. In mothers with AAV DNA-positive amnion fluids, premature amniorrhexis and premature labour occurred significantly more frequently (P < 0.001). Using an immunofluorescence assay, 24% of newborn sera (unrelated to the amnion fluid samples) were found to contain IgM antibodies to AAV, in most cases paralleled by IgM antibodies in the mother's sera. The data demonstrate that AAV infection can occur in utero at early and at late stages of pregnancy. The observed complications at delivery should encourage studies to clarify possible pathological consequences of AAV infection in pregnancy and a possible latent infection of the fetus.

A study of anal intraepithelial neoplasia in HIV positive homosexual men

OBJECTIVES

To determine the prevalence of high grade anal intraepithelial neoplasia (HGAIN), the value of anal cytology in screening for HGAIN, and the characterisation of epidemiological factors and human papillomavirus (HPV) types.

METHODS

Prospective cohort study of HIV positive homosexual men. Subjects were interviewed, underwent STD, anal cytological, and HPV screening at enrolment and at subsequent follow up visits with anoscopy and biopsy at the final visit. 57 enrolled, average CD4 count 273 x 10(6)/l (10-588); 41 completed the cytological surveillance over the follow up period (181 visits, average follow up 17 months), 38 of these had anoscopy and anal biopsy.

RESULTS

Oncogenic HPV types were detected in 84% and high grade dyskaryosis in 10.5% (6/57) at enrollment. There was a 70% incidence of high grade dyskaryosis during follow up in patients with negative/warty or low grade dyskaryosis at enrollment. Anoscopy correlated with histology in high grade AIN lesions (sensitivity 91%, specificity 54%) and cytology was 78% sensitive (18/23) for HGAIN on biopsy.

CONCLUSIONS

AIN and infection with multiple oncogenic HPV types are very common among immunosuppressed HIV positive homosexual men. Apparent progression from low to high grade cytological changes occurred over a short follow up period, with no cases of carcinoma. All 23 cases of HGAIN were predicted by cytology and/or anoscopy. Future studies focusing on the risk of progression to carcinoma are needed before applying anal cytology as a screening tool for AIN in this population.

Risk factors for human papillomavirus and cervical precancerous lesions, and the role of concurrent HIV-1 infection

OBJECTIVES

To identify risk factors for human papillomavirus (HPV) infection and squamous intraepithelial lesions (SIL) of the cervix, and to measure the impact of concurrent HIV-1 infection.

METHODS

Women were studied at a family planning clinic in Nairobi, Kenya. Demographic and historical information was obtained using a semi-structured questionnaire and specimens were collected for sexually transmitted diseases (STDs), HPV, cervical cytology, and HIV-1 testing.

RESULTS

HPV was detected in 87 of 513 women (17%), including 81 (93%) oncogenic types (16, 18, 31, 33 and others) and six (7%) non-oncogenic types (6 and 11). HIV-1 prevalence was 10%. HPV detection was associated with HIV-1 infection [adjusted odds ratio (aOR) 3.9, 95% confidence interval (CI), 2.0-7.7], sexual behavior indicators including the number of sex partners and inflammatory STDs, as well as the number of pregnancies (0 or 1 vs. > or = 3, aOR 0.4; 95% CI, 0.2-0.9). SIL was detected in 61 women (11.9%), including 28 (46%) with low-grade lesions (LSIL) and 33 (54%) with high-grade lesions (HSIL). HPV infection was strongly associated with HSIL (OR 14.9; 95% CI, 6.8-32.8). In a multivariate model predictors of HSIL included HIV-1 serpositivity (aOR 4.8; 95% CI, 1.8-12.4), the number of lifetime sex partners (0-1 vs. > or = 4; aOR 3.8; 95% CI, 1.1-13.5), and older age (< 26 vs. > 30; OR 3.9; 95% CI, 1.1-13.6). An analysis stratified by HIV-1 showed a stronger association between HPV and HSIL in HIV-1 negative women (OR 17.0; 95% CI, 6.4-46.3) then in HIV-1 positive women (OR 4.5; 95% CI, 0.8-27.4).

CONCLUSION

Our results indicate that HSIL and even invasive cancer are highly prevalent in this setting of women on reproductive age considered to be at low risk for STDs, suggesting that routine Pap smear screening may save lives.

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.

Detection and identification of human papilloma viral DNA, types 16, 18, and 33, by a combination of polymerase chain reaction and a colorimetric solid phase capture hybridisation assay

A colorimetric microplate hybridization assay was developed previously to simplify detection procedures of DNA fragments resulting from polymerase chain reactions (PCR). This format has now been adapted for the simultaneous detection and identification of three human papillomavirus (HPV), types 16, 18 and 33, associated frequently with cervical cancer. This post-PCR detection system uses three type-specific capture oligonucleotides linked covalently to a single microplate well and three type-specific multibiotinylated oligonucleotidic probes for detection. It therefore offers a double specificity; the first is conferred by pairs of primers, specific of each type of virus tested, and the second, by the sets of capture and detection probes which are complementary to internal regions of the amplified DNA fragments. The detection format outperformed agarose gel electrophoresis of amplified DNA products in sensitivity and specificity. The rapidity and simplicity of this hybridisation system would justify its use in routine diagnostic examination of cervical specimens (smears and biopsies).

Molecular analysis of ras oncogenes in CIN III and in stage I and II invasive squamous cell carcinoma of the uterine cervix

AIM

To examine the prevalence of genital type human papilloma virus (HPV) and mutations at codons 12, 13, and 61 in H, Ki, and N-ras in CIN III and early invasive squamous cell carcinomas of the cervix.

METHODS

Prevalence of HPV was examined in 20 CIN III and 20 stage I and II cervical carcinomas, using non-isotopic in situ hybridisation (NISH) and solution phase polymerase chain reaction (PCR). In addition, mutations at codons 12, 13, and 61 were examined in H, Ki, and N-ras in these CIN III and early invasive squamous cell carcinomas, to assess the prevalence of ras gene point mutations and to define where in the pathobiology of squamous cell carcinoma such events occur. A non-isotopic PCR/RFLP assay was used to define these mutations.

RESULTS

Of the 20 CIN IIIs examined, 19 contained HPV 16 DNA sequences by PCR and NISH. Dual infection was not uncovered. The 20 early (stage I and II) invasive squamous cell carcinomas showed predominant HPV 16 positivity (17/20), with one case HPV 18 positive, confirmed on PCR and NISH. Activating mutations were not identified in any of the CIN III cases. Only one stage I, HPV 16 positive carcinoma showed an activating mutation in H-ras codon 12, which was not present in adjacent normal ectocervical mucosa from the same patient.

CONCLUSIONS

ras Activation does not appear to occur in conjunction with HPV infection, particularly of HPV 16 infected high grade cervical intraepithelial neoplasia, or to occur commonly in early cervical squamous cell carcinoma. The postulated model of HPV linked carcinogenesis suggests malfunctional control of viral transcription as a necessary component of neoplastic progression. It is also clear that host gene alterations are equally necessary for HPV linked carcinogenesis to occur.

Different risk factor patterns for high-grade and low-grade intraepithelial lesions on the cervix among HPV-positive and HPV-negative young women

Risk factors for cervical intraepithelial neoplasia have most often been studied in high-grade lesions. Furthermore, in a high proportion of the studies, human papillomavirus (HPV), the most significant risk determinant of cervical neoplasia, was not taken into account when evaluating other risk factors. To compare risk factors for ASCUS (atypical cells of undetermined significance), LSIL (low-grade squamous intraepithelial lesion) and HSIL (high-grade squamous intraepithelial lesion), we conducted a case-control study among 20 to 29 year-old women participating in a prospective cohort study in Copenhagen. It included 131 women with ASCUS, 120 women with LSIL, 79 women with HSIL and 1,000 randomly chosen, cytologically normal, control women. All participants had a personal interview and a gynecological examination including a Pap smear and cervical swabs for HPV DNA detection using general primer-mediated polymerase chain reaction. The most significant risk determinant of all 3 disease categories was the presence of genital HPV DNA. The risk factor pattern was nearly identical for ASCUS and LSIL, but differed significantly from that for HSIL. Stratified analysis by HPV-status showed that, apart from, respectively, smoking and parity among HPV-positive women, and smoking and number of sex partners among HPV-negative women, no additional risk factors were observed for ASCUS and LSIL. In contrast, among HPV-negative women with HSIL, long-term use of oral contraceptives was the most important risk factor. However, our result should be taken with great caution as it is based on very small numbers, and as it is unknown whether the HPV-negative lesions constitute a true entity. Among HPV-positive women, the risk of HSIL was associated with e.g., years of sex life without barrier contraceptive use, early age at first genital warts and smoking. Whether the risk factors that are applicable only to HSIL represent factors related to progression remains unknown.

Human papillomavirus and mixed epithelial tumors of the endometrium

Strong epidemiological evidence links human papilloma viruses (HPV) with the development of cervical intraepithelial neoplasia (CIN) and invasive cancers of the uterine cervix. The localization of HPV DNA sequences high up in the female genital tract (in benign and malignant lesions) is not that uncommon, but its precise significance is uncertain. In particular, the detection of HPV DNA sequences by polymerase chain reaction (PCR) needs careful interpretation, because the source of the amplicon may emanate from tumor cells, direct contamination from the cervix, or possibly from extratumoral sites in the endometrium. We have previously reported the identification of koilocyte-like changes in the squamous epithelium of some endometrial adenoacanthomas. Adenoacanthomas (adenocarcinoma with squamous metaplasia) are mixed epithelial tumors arising in the endometrium composed of malignant glandular areas admixed with benign metaplastic squamous epithelium. The rarer adenosquamous carcinoma containing both malignant glandular and squamous areas is also described. The origin of benign/malignant squamous epithelial islands in endometrial tumors has been the subject of speculation, with some investigators considering an origin from metaplastic glandular endometrial cells. In this study, we examined 10 normal endometrial samples, 20 adenocarcinomas, 41 adenocarcinomas with squamous metaplasia, and two adenosquamous carcinomas, (including control cervical material where possible) for the presence of HPV DNA sequences using nonisotopic in situ hybridization (NISH), type-specific HPV PCR, general primer PCR (to detect sequenced and unsequenced HPVs), and PCR in situ hybridization (PCR-ISH). We did not identify HPV DNA sequences in normal endometrial tissue. In adenocarcinomas (endometrioid type), HPV was only identified in 2 of 20 cases by PCR, both of which were HPV 11 positive. We were unsuccessful in identifying HPV in endometrial carcinomas by NISH or by PCR-ISH, raising the possibility of contamination from the cervix in the two positive cases. In adenoacanthomas, a low-risk HPV type (HPV 6) was found in 19 of 41 cases. NISH signals were intranuclear in location in squamous regions of adenoacanthomas. Additional positive nuclei were uncovered using PCR-ISH, which increases the sensitivity of standard NISH detection. HPV DNA sequences were located in some malignant endometrial glandular epithelial cells, but this accounted for a minority of samples. HPV DNA sequences were not detected in extraepithelial sites. Mixed infection by two different HPV types was identified in two cases. Most cases showed similar HPV types in cervical and endometrial lesions, although discordant cases were uncovered. In adenosquamous carcinomas, one case showed mixed infection with HPV 6 and 33 by PCR. The apparent segregation of low-risk HPV type (HPV 6) with benign squamous metaplastic epithelium in adenocarcinoma with squamous metaplasia, and high-risk type (HPV 33) with malignant squamous epithelium in adenosquamous carcinoma, raises important questions in relation to the role of HPVs in mixed epithelial tumors of the endometrium and their interplay in the pathogenesis of squamous metaplasia at extracervical sites.

Presence of papillomavirus-like DNA sequences in cutaneous fibropapillomas of the goat udder

Papillomatous lesions were isolated from the mammary skin of goats and examined for evidence of papillomavirus (PV) infection by various criteria, including gross morphology, histology and DNA hybridization. Although some lesions showed gross papillomatous morphological and histological features similar to those caused by papillomavirus in other species, no viral particles were detected. Reverse slot hybridization revealed cross-hybridization between DNA extracted from goat mammary papillomas and human papillomaviruses (HPV). Southern blot, using ovine papillomavirus (OPV) and bovine papillomavirus type 5 (BPV 5) DNA probes under conditions of reduced stringency (Tm -40 degrees C), detected homologous sequences in 40% of the biopsies. DNA fragments corresponding probably to a monomeric form (7000-8000 bp) of an unknown papillomavirus genome were detected. This study provides evidence for the existence of papillomavirus-like sequences in caprine mammary papillomas and suggests that a papillomavirus is likely to be involved in the development of precancerous lesions of goat mammary skin.

Combined Epstein-Barr virus and human papillomavirus infection in nasopharyngeal carcinoma

Epstein-Barr virus (EBV) has been shown to be a likely etiologic agent in nasopharyngeal carcinogenesis. Human papillomaviruses (HPVs) have previously been identified in numerous upper aerodigestive tract carcinomas. This pilot study was undertaken to investigate the prevalence of combined EBV and HPV infection in 17 patients with nasopharyngeal carcinoma (NPCA) using polymerase chain reaction (PCR). The primary goal was to determine if the presence of HPV could be correlated with molecular, histologic, or clinical parameters. There were seven patients with undifferentiated NPCA (World Health Organization [WHO] type III) and 10 patients with squamous cell carcinoma (WHO type I). All 17 patients had stage IV disease at presentation. EBV was identified in 15 patients (88.2%), and HPV subtypes were identified in samples from nine patients (52.9%). All HPV-positive cases were also EBV positive. Western blot analysis of six samples showed a high level of expression of c-myc and cdc2 kinase and a low level of p53 protein in NPCAs that contained both HPV and EBV (n = 3). Increased expression of c-myc and cdc2 kinase was seen in the cases that contained EBV only, but to a lesser extent (n = 2). These findings indicate an effect of the virus on cellular proliferation and differentiation. Similarly, an elevated level of Rb protein was found only in the HPV-containing NPCAs. Moderate differentiation (keratinization) occurred in four of eight HPV-negative and none of the nine HPV-positive NPCAs. (All HPV-positive cases were poorly differentiated or undifferentiated.) This difference is statistically significant for this sample size (P < 0.03). There was a trend for the group that was HPV positive to have WHO III histology and for the HPV-negative group to have WHO I. The presence of HPV could not be correlated with any clinical parameters in this small group of patients with advanced disease; however, these data suggest that coexistence of EBV and HPV infection may be a factor in the pathogenesis of NPCA and may have an effect on regulation of cellular proliferation and differentiation.

Risk factors for HPV infection in women from sexually transmitted disease clinics: comparison between two areas with different cervical cancer incidence

We have compared risk factors for human papillomavirus (HPV) infection in very sexually active women [attenders of clinics for sexually transmitted diseases (STDs)] living in 2 areas with a 4-fold difference in cervical cancer incidence, i.e., Greenland and Denmark. The results were compared with findings of HPV infection in men attending the STD clinics during the same period. Overall, 204 Greenlandic women (GW), 187 Danish women (DW), 103 Greenlandic men and 216 Danish men were included. A similar age distribution was found in the 2 female populations. The GW reported significantly more sexual partners, earlier first intercourse and more STDs, but HPV was less frequently detected in the GW (25%) than in the DW (35%). However, this could be explained by a difference in the age pattern of HPV prevalence seen in the 2 areas. In each geographical area, the age pattern of HPV prevalence in men was very similar to that seen in women. The most important risk factors for HPV detection were the same in both female populations, i.e., age, years since first sexual intercourse and number of partners in the last years. In conclusion, the pattern of risk factors for HPV infection was the same in STD women from a high-risk area and a low-risk area for cervical cancer. Our results also show that the use of an overall HPV prevalence for comparing populations is meaningless, even in populations with similar age distribution.

Human papillomavirus and oesophageal squamous cell carcinoma in the UK

Human papillomavirus (HPV) has previously been identified in up to 67% of squamous cell carcinomas of the oesophagus. In particular, HPV types of 16 and 18 are believed to play an important role in neoplastic transformation, by means of their oncoproteins E6 and E7. Most of these studies, however, pertain to areas of high incidence of squamous cell carcinoma of the oesophagus (the Far East and South Africa). It is not known if HPV plays any role in the development of oesophageal squamous cell carcinoma in the UK, where the tumour is relatively uncommon. The polymerase chain reaction was used to examine frozen tissue from 22 oesophageal squamous cell carcinomas for the presence of specific DNA sequences from oncogenic strains of HPV. PCR products were further analysed by Southern blot hybridization. No HPV sequences were detected in any tumours. These results suggest that these types of HPV are not associated with oesophageal squamous cell carcinoma in this country. It is unlikely, therefore, that HPV plays a significant role in the pathogenesis of squamous cell carcinoma of the oesophagus in the UK.