Prevalence of HPV DNA and viral copy numbers in cervical scrapes from women with normal and abnormal cervices

Prevalence of human papillomaviruses in the healthy oral mucosa of women with high-grade squamous intra-epithelial lesion and of their partners as compared to healthy controls

Oral human papillomavirus (HPV) carriage rates were investigated in relation to genital HPV carriage in women with HPV-associated cervical lesions and male partner of such women, including several couples, in comparison with healthy individuals. Buccal and lingual mucosa of 60 males and 149 females with healthy oral mucosa and without known genital lesion, genital and oral mucosa of further 40 females with cervical high-grade squamous intraepithelial lesion (HSIL) and 34 male sexual partners of women with HSIL (including 20 couples) were sampled. HPV DNA was detected using MY/GP PCR. Genotype was determined by sequencing or restriction fragment length polymorphism. Virus copy numbers were determined by real-time PCR. Overall, oral HPV carriage rate was 5.7% (12/209) in healthy individuals; average copy number was 5.8 × 10(2) copies/1 μg DNA; male and female rates were comparable. Oral carriage in women with HSIL was significantly higher, 20.0% (8/40, P = 0.003); males with partners with HSIL showed a carriage rate of 17.6% (6/34), copy numbers were similar to the healthy controls. In contrast, genital carriage rate (52.9%, 18/34 vs. 82.5%, 33/40; P = 0.006) and average copy number were lower in males (5.0 × 10(5) vs. 7.8 × 10(5) copies/1 μg DNA; P = 0.01). Oral copy numbers in these groups and in healthy individuals were comparable. High-risk genotypes were dominant; couples usually had the same genotype in the genital sample. In conclusion, genital HPV carriage is a risk factor of oral carriage for the individual or for the sexual partner, but alone is not sufficient to produce an oral HPV infection in most cases.

Development and evaluation of a PCR and mass spectroscopy (PCR-MS)-based method for quantitative, type-specific detection of human papillomavirus

Knowledge of the central role of high-risk human papillomavirus (HPV) in cervical carcinogenesis, coupled with an emerging need to monitor the efficacy of newly introduced HPV vaccines, warrant development and evaluation of type-specific, quantitative HPV detection methods. In the present study, a prototype PCR and mass spectroscopy (PCR-MS)-based method to detect and quantitate 13 high-risk HPV types is compared to the Hybrid Capture 2 High-Risk HPV DNA test (HC2; Digene Corp., Gaithersburg, MD) in 199 cervical scraping samples and to DNA sequencing in 77 cervical tumor samples. High-risk HPV types were detected in 76/77 (98.7%) cervical tumor samples by PCR-MS. Degenerate and type-specific sequencing confirmed the types detected by PCR-MS. In 199 cervical scraping samples, all 13 HPV types were detected by PCR-MS. Eighteen (14.5%) of 124 cervical scraping samples that were positive for high-risk HPV by HC2 were negative by PCR-MS. In all these cases, degenerate DNA sequencing failed to detect any of the 13 high-risk HPV types. Nearly half (46.7%) of the 75 cervical scraping samples that were negative for high-risk HPV by the HC2 assay were positive by PCR-MS. Type-specific sequencing in a subset of these samples confirmed the HPV type detected by PCR-MS. Quantitative PCR-MS results demonstrated that 11/75 (14.7%) samples contained as much HPV copies/cell as HC2-positive samples. These findings suggest that this prototype PCR-MS assay performs at least as well as HC2 for HPV detection, while offering the additional, unique advantages of type-specific identification and quantitation. Further validation work is underway to define clinically meaningful HPV detection thresholds and to evaluate the potential clinical application of future generations of the PCR-MS assay.

Human papillomavirus 6 seropositivity is associated with risk of head and neck squamous cell carcinoma, independent of tobacco and alcohol use

BACKGROUND

The risk of head and neck squamous cell carcinoma (HNSCC) associated with common human papillomavirus types has not been well defined.

METHODS

We conducted a case-control study of 1034 individuals (486 incident cases diagnosed with HNSCC and 548 population-based controls matched to cases by age, gender, and town of residence) in Greater Boston, MA. Sera were tested for antibodies to human papillomavirus (HPV)6, HPV11, HPV16, and HPV18 L1.

RESULTS

HPV6 antibodies were associated with an increased risk of pharyngeal cancer [odds ratio (OR)=1.6, 1.0-2.5], controlling for smoking, drinking, and HPV16 seropositivity. In HPV16-seronegative subjects, high HPV6 titer was associated with an increased risk of pharyngeal cancer (OR=2.3, 1.1-4.8) and oral cancer (OR=1.9, 1.0-3.6), suggesting that the cancer risk associated with HPV6 is independent of HPV16. There was no association between smoking and alcohol use and HPV6 serostatus. Further, the risk of pharyngeal cancer associated with heavy smoking was different among HPV6-seronegative (OR 3.1, 2.0-4.8) and HPV6-seropositive subjects (OR=1.6, 0.7-3.5), while heavy drinking also appears to confer differing risk among HPV6-negative (OR 2.3, 1.5-3.7) and -positive subjects (OR=1.3, 0.6-2.9).

CONCLUSIONS

There may be interactions between positive serology and drinking and smoking, suggesting that the pathogenesis of human papillomavirus in HNSCC involves complex interactions with tobacco and alcohol exposure.

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.

High-risk human papillomavirus types and squamous cell carcinoma in patients with respiratory papillomas

Respiratory papillomas (RPs) are benign, virally induced tumors of the larynx and respiratory epithelium that may obstruct the airway and tend to recur frequently. RPs are thought to be the result of infection with the human papillomaviruses (HPVs) types 6 and 11. We surveyed archival RP specimens to determine whether there were correlations of HPV type with patient characteristics or clinical course. Paraffin-embedded papilloma specimens of 45 different patients were analyzed. We assessed HPV types using the polymerase chain reaction with E6 consensus primers, hybrid capture assays (high or low risk), and dot blot hybridization of generic E6 PCR products with E6 type-specific oligonucleotide probes. The presence and type of HPV were correlated with patient data from a retrospective chart review. We found that RPs may have either low- or high-risk HPV types and some contain multiple HPV types. Respiratory infection with high-risk HPV apparently introduces a long-term risk of squamous cell carcinoma development, even in the absence of conventional cofactors. Low-risk HPV infection may also act in association with these cofactors to promote carcinogenesis. Our data also show a racial imbalance in RP that may indicate a difference in genetic resistance and/or susceptibility to HPV infection and the development of RP.

Genital human papillomavirus infections in Taiwan

OBJECTIVES

Identification and typing of HPV infections in genital condyloma and normal cytological cervix.

METHODS

Cervical cells from 289 Pap cases with normal cytological findings were examined for HPV infection by slot blot hybridization. Fifteen condyloma biopsy specimens were studied by Southern blot hybridization.

RESULTS

Thirty-six cases (12.5%) with normal cervical cytology were HPV positive. The predominant HPV type in women with normal cytology is HPV-16. Risk factors for HPV infection in women with normal cytology depend on age and history of pregnancies. Twelve cases (80%) of condyloma contained HPV-6 or -11 sequences. The predominant HPV type in genital condyloma is HPV-11.

CONCLUSIONS

HPV detection in population-based screening programs for cervical neoplasia can be an important tool in identifying women who are at risk of developing dysplasia and cervical cancer.

Detection of human papillomavirus DNA by in situ hybridization and polymerase chain reaction in human papillomavirus equivocal and dysplastic cervical biopsies

One hundred twenty-one paraffin-embedded cervical biopsy specimens were tested for the presence of human papillomavirus (HPV) DNA by in situ hybridization and polymerase chain reaction. By in situ hybridization using probes for HPV types 6/11, 16/18, 31/33/35, 42/43/44, 51/52, and 45/56, HPV DNA was found in none of 20 normal/squamous metaplasia biopsy specimens, in one of 76 HPV equivocal biopsy specimens, in seven of 12 condyloma/mild dysplasia biopsy specimens, and in 12 of 13 moderate/severe dysplasia biopsy specimens. Polymerase chain reaction using HPV L1 consensus sequence primers followed by filter hybridization of the amplification products was positive for HPV DNA in two of 20 normal/squamous metaplasia biopsy specimens, in 23 of 76 HPV equivocal biopsy specimens, in eight of 12 condyloma/mild dysplasia biopsy specimens, and in 12 of 13 moderate/severe dysplasia biopsy specimens. Among biopsies that tested positive by polymerase chain reaction but that were negative by in situ hybridization, the most commonly identified HPV was type 16. We conclude that although HPV equivocal biopsy specimens contain HPV DNA more frequently than histologically normal tissue, the majority of biopsy specimens in this category test negative for HPV DNA. The clinical significance of a positive test for HPV, in the absence of unequivocal histologic changes, remains to be determined.

Pathogenesis of genital HPV infection

Clinical, subclinical, and latent human papillomavirus (HPV) infections are distinguished from HPV-associated neoplasia. Besides HPV additional cofactors are necessary to transform HPV infected tissue to intraepithelial or invasive neoplasia. Risk factors for the presence of HPV are high number of sexual partners, early cohabitarche, young age at first delivery, suppression and alteration of immune status, young age and hormonal influences. While the fact of a high number of sexual partners exclusively increases the risk of HPV infection, it is not known whether the other factors lead to either an increased risk for HPV infection and/or to HPV-associated neoplasia. Subclinical and latent genital HPV infections are highly prevalent. The prevalence rate depends on the sensitivity of the HPV detection system used, on age and sexual activity of the population screened, and on the number of subsequent examinations performed for each subject. Sexual transmission is the main pathway for genital HPV's, however, vertical, peripartal, and oral transmission are also possible. Seroreactivity against genital HPV may be due to an active infection or the result of contact with HPV earlier in life. Antibodies against the HPV 16 E7 protein indicate an increased risk for cervical cancer. Compared with humoral response cellular immune response is probably more important for regression of genital HPV infection: impaired cellular response is characterized by depletion of T helper/inducer cells and/or Langerhans cells and impaired function of natural killer cells and/or the infected keratinocyte. In condylomata replication and transcription of viral nucleic acids and antigen production coincide with cellular differentiation. However, the interaction between HPV and the keratinocyte on a molecular level in subclinical and latent disease is not well understood. Regression or persistence of subclinical and latent genital HPV infections as observed in longitudinal investigations show a constant come-and-go of HPV presence. Subclinical or latent cervical infections with high-risk HPV types (such as HPV 16 and 18) have an increased risk for the development of HPV-associated neoplasia.

Prevalence of HPV in cytomorphologically normal cervical smears, as determined by the polymerase chain reaction, is age-dependent

The prevalence of human papillomavirus (HPV) genotypes in relation to age was investigated by the polymerase chain reaction (PCR) method in cytologically normal smears from 4 different groups of women. Group A consisted of young women from a district population, aged 15-34 years, using oral contraceptives and visiting general practitioners for a check-up (n = 156); group B were asymptomatic women, aged 35-55, in a district population participating in a triennial screening program for cervical cancer (n = 1555); group C and D consisted of women, seen at the gynecological outpatient department for a wide spectrum of gynecological complaints or for control of their hormonal contraception, aged 15-34 years (n = 2320), and aged 35-55 years (n = 1826) respectively. An HPV (all types) prevalence of 14.1%, 4.1%, 13.9% and 6.6% and an HPV 16/18 prevalence of 3.8%, 0.9%, 3.3% and 1.5% were found in groups A, B, C and D respectively. Statistically significant differences (p value < 0.001) in HPV prevalence were found between women aged 15-34 years and women aged 35-55 years in the district population and in the hospital population. No statistically significant differences in HPV 16/18 were observed after age-matching between women in corresponding age-classes of both populations. In a 5-year interval analysis a strong age-dependent relationship was demonstrated, with a maximum between 20 and 24 years. After the age of 35 a constant level of 1-2% HPV 16/18 was observed. These results indicate that genital HPV infections are age-dependent and suggest that HPV infections at young age can be transient. The implications of these findings in the context of cervical cancer screening are discussed.

Dual infection with human papillomavirus in a population with overt genital condylomas

BACKGROUND

Multiple human papillomavirus (HPV) genotypes have been demonstrated in individual patients; usually, different genotypes occur in different anatomic sites.

OBJECTIVE

Our purpose was to evaluate the prevalence of multiple HPV types from the same anatomic site.

METHODS

During the course of a study evaluating topical versus ablative therapy for external genital HPV, sequential biopsies on patients with external genital warts were performed. HPV DNA content was determined by Southern hybridization. Ninety-two specimens from 63 patients (48 women, 15 men) with genital warts were evaluated.

RESULTS

Dual infection with two HPV genotypes was documented in each of four specimens (6.3%). Sequential biopsy specimens from the same anatomic site in the same person revealed dual infection in 5 of 12 sampled patients (41%). Overall, 14% of patients had dual genitourinary HPV infection.

CONCLUSION

Counseling and follow-up of long-term complications, such as transmission and the risk of subsequent genitourinary carcinoma, should be performed on all patients with HPV because of the possibility of undetected HPV DNA types in the individual patient.

Comparative analysis of human papillomavirus detection by dot blot hybridisation and non-isotopic in situ hybridisation

AIMS

To determine the relative diagnostic performance of non-isotopic in situ hybridisation (NISH) and a dot-blot assay for detecting human papillomavirus (HPV) on exfoliated cervical cells; and to correlate the results with cytopathological assessment.

METHODS

Cervical smears and cytological samples were obtained from 122 patients during the same clinical examination and the presence of HPV sequences determined by NISH and dot-blot analysis, respectively.

RESULTS

Dot-blot analysis gave an autoradiographic signal in 15 of 121 (12.4%) cases, while NISH detected viral genomes in 38 of 114 (33.3%) cases. Even in the presence of koilocytosis, where vegetative replication of the virus occurs, NISH was positive in over twice as many cases as dot-blot analysis (NISH 90%, dot-blot 40%), while in smears within normal cytological limits, where the viral copy number is likely to be considerably lower, the differences were more striking (NISH 31%, dot-blot 5%).

CONCLUSIONS

These data show that NISH on cytological smears is more sensitive than a standardised dot-blot hybridisation assay for detecting HPV infection in cytological material and is therefore a more appropriate screening tool.

Prevalence of human papillomavirus (HPV) infection in Basque Country women using slot-blot hybridization: a survey of women at low risk of developing cervical cancer

Cervical smears from 1,178 women with cytologically normal cervices and 67 women with cervical intra-epithelial neoplasia (CIN) or cervical carcinoma were analyzed for the presence of HPV 6, 11, 16 and 18 DNA by slot-blot hybridization. HPV DNA was detected in 17% (95% CI: 14%-19%) of the women with a normal smear; 11% of infected women harboured HPV 16 and 18 (95% CI: 9%-13%, each). HPV DNA was detected in 54% (95% CI: 41%-66%) of patients with abnormal smear; the most prevalent virus type in this group was HPV 16 (45%; 95% CI: 32%-38%). In order to verify the slot-blot results, a proportion of the samples was also investigated by PCR. There was 88% correlation between the 2 tests. The high prevalence of HPV 16 and 18 infection demonstrated in our low-cervical-cancer-risk area further support the role of as yet unidentified co-factors as determinants of the different geographic rates of cervical-cancer incidence.

Detection of human papillomavirus in matched cervical smears and biopsy specimens by non-isotopic in situ hybridisation

AIMS

To determine the relative diagnostic sensitivity of non-isotopic in situ hybridisation (NISH) for the diagnosis of human papillomavirus (HPV) on matched smears and biopsy specimens; to compare the NISH signal type in the two samples; and to correlate the NISH data with the morphological diagnosis.

METHODS

HPV samples were assayed individually by NISH with digoxigenin labelled probes (HPV6, 11, 16, 18, and 33) on routinely collected paraffin wax embedded cervical biopsy specimens and for high risk HPVs with a cocktail of similarly labelled probes (HPV16, 18, 33) on matched smears. These were taken at the same colposcopic examination from 32 patients investigated for an abnormal cervical Papanicolaou (PAP) stained smear.

RESULTS

An HPV signal was present in 18 (56%) biopsy specimens and in 14 (44%) smears. There was higher concordance of sets of data in the presence of cytopathic wart virus changes. The superiority of biopsy over smear in detecting HPV was mainly the result of examining the entire cervical biopsy specimen rather than cells scraped from the cervical surface. The NISH signal type in both biopsy specimen and smear was similar; it has been shown that NISH type 1 signal correlates with episomal viral replication and type 2 and 3 signals with viral integration.

CONCLUSIONS

These data show that NISH on cervical smears is a worthwhile primary screen for HPV infection. The NISH signal types in cervical smears are similar to those previously described in cervical biopsy specimens.

Prevalence of HPV cervical infection in a family planning clinic determined by polymerase chain reaction and dot blot hybridisation

The overall prevalence of human papillomavirus (HPV) cervical infection in 131 women attending a family planning clinic was 7% (HPV 6/11, 16, 18, 31) by dot blot hybridisation, 53% (HPV 11, 16, 31) by polymerase chain reaction (PCR), and 56% by the two methods combined. HPV 16 and 18 were the commonest types (4% each) by dot blot, HPV 16 (39%) by PCR. Fifteen percent of subjects had mildly abnormal cervical cytology (grades 1A, 2A, or 3). There was no significant correlation between cytological abnormality and HPV positivity, or between cytological or HPV status and other postulated risk factors for cervical neoplasia. It is concluded that PCR is considerably more sensitive than dot blot DNA hybridisation in detecting HPV cervical infection in such a "low risk" setting, where HPV copy number may be low. Firm conclusions cannot be drawn from our results regarding a causal role for HPV or other factors in the development of cervical neoplasia.

Human papillomavirus DNA types in squamous cell carcinomas of the head and neck

Previous studies have found variable evidence suggestive of a role for human papillomavirus (HPV) in squamous cell carcinoma of the head and neck. In this study 49 cases of primary verrucous or squamous cell carcinoma from patients referred to a regional medical center were examined initially by Southern blot hybridization to detect HPV types 2, 6, 11, 13, 16, 18, and 32. Approximately 60% of carcinomas from certain head and neck sites, particularly the floor of the mouth, tongue, pharynx, piriform sinus, and larynx, were positive for episomal viral DNA of HPV-6, -11, -16, or -18. HPV DNA was found in some multiple tumors from separate sites of the same patient. Integration of viral DNA into the host cell chromosome was likely in a minority of the positive carcinomas, and no novel HPV DNA types were indicated by the hybridization analyses. Subsequently, DNA remaining from 30 of the carcinomas was examined by a more sensitive polymerase chain reaction amplification assay for DNA of HPV-6, -11, -16, and -18. Twenty-seven of the samples were positive for one or more HPV DNA types, with all positive carcinoma samples containing oncogenic HPV-16 or -18 DNAs. Almost all the patients examined were of the middle to older age group with a history of tobacco use. Although HPV infection of oral mucosa may be a frequent occurrence, a possible role for HPVs in the multifactorial etiology of head and neck carcinogenesis merits further epidemiologic investigation.

The prevalence of human papillomavirus type 16 and 18 DNA in cervical cancer in different age groups: a study on the incidental cases of cervical cancer in Norway in 1983

In a study carried out to estimate the prevalence of genital Human Papilloma Virus (HPV) infection among cervical cancer patients in Norway, the following values were recorded using the southern blot hybridization method: 54.1% HPV 16, 9.5% HPV 18, 0% HPV 11, and 1.4% HPV 16 and 18 coinfection, yielding a total of 62.2% HPV positive cases in the study. An attempt to include a normal biopsy as "internal control" from each patient failed, as macroscopically normal tissue was often histologically abnormal. HPV infection did not relate to stage of disease, age, or 5-year survival, whereas the classic relationship between stage and survival was observed. A very high percentage of HPV positive cases occurred among older women, a fact which does not support the existence of a new HPV epidemic. The studied population is unique, as it represents 75 cases which comprise a representative sample of the 372 incidental cases of cervical cancer in Norway in 1983. To our knowledge this is the first study of its kind.

Human papillomavirus infections of the genital tract

Infection of the genital tract by HPV is a sexually transmitted disease of increasing prevalence. The association of HPV infection with genital tract malignancies is of great concern, and further studies are needed to clarify this association. Few investigators believe at this time that proof of a direct causative role exists for HPV in these cancers, but indirect evidence of such a role is abundant. There are many clinical forms of HPV infection of the genital tract, and few clinicians can easily recognize them all. Treatment of condyloma acuminatum is difficult and frustrating. Cryotherapy with liquid nitrogen is the safest and most effective therapy for most forms of condyloma acuminatum. Recurrence of condyloma acuminatum is common with all presently used forms of therapy, probably owing to latent HPV infection in normal-appearing skin. No form of treatment is ideal for all forms of condyloma acuminatum, but without continued efforts to find better therapeutic modalities and preventative measures, the epidemic of genital HPV infection will continue unchecked.

Time trends in the prevalence of human papillomavirus infections in archival Papanicolaou smears: analysis by cytology, DNA hybridization, and polymerase chain reaction

A retrospective study was undertaken to determine the prevalence of human papillomavirus (HPV) infections in routine Papanicolaou (Pap) smears collected by general practitioners from Western Australian women in each of the years 1972, 1982, and 1987. HPV infection was detected by cytology, dot-blot hybridization, or polymerase chain reaction (PCR). It was found that the prevalence of HPV infection remained unchanged over the 15 year study period, was independent of age, and was associated with normal cytology at a rate far greater than previously recognized. Indeed, the prevalence of cervical intraepithelial neoplasia (CIN) lesions, as detected by cytology, was 3.0% in 1972 and 3.8% in 1982 and 1987. The prevalence of HPV infection, detected as koilocytosis or parakeratosis, was 6.5%, 6.8%, and 5.3% in smears collected in 1972, 1982, and 1987, respectively, from 1,800 women. In 237 cytologically normal smears reprocessed for HPV-DNA studies, the prevalence of HPV 16 was determined to be 15.6%, 11.2%, and 17.8% in 1972, 1982, and 1987, respectively, as determined by dot-blot hybridization. However, the PCR detected HPV 16 in an additional 55.5%, 62.9%, and 57.0% of cytologically normal and dot-blot negative smears. The prevalence of HPV 16 infection in cytologically normal smears was estimated to be 71.0%, 74.1%, and 74.8% in 1972, 1982, and 1987, respectively, by combining the HPV 16 dot-blot and PCR-positive results. The high prevalence of HPV 16 in cytologically normal Pap smears suggests that infection with HPV 16, as detected by PCR amplification, does not place women in a high-risk category for cervical cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Automated polymerase chain reaction for papillomavirus screening of cervicovaginal lavages: comparison with dot-blot hybridization in a sexually transmitted diseases clinic population

The aim of the present study was to compare the recently developed polymerase chain reaction (PCR) technique with conventional dot-blot DNA hybridization for human papillomavirus (HPV) detection. Cells were collected by cervicovaginal lavage from a study group of 109 women attending a sexually transmitted diseases clinic. Using a machine that we developed for alternation of temperature cycles, HPV was detected in 51% of patients by PCR. By dot-blot hybridization, 44% of the patients were positive. Concordance of combined positive and negative results between PCR and dot blot was 69%. The greater sensitivity of PCR may have accounted for 19% of specimens that were PCR positive but dot-blot negative. Unexpectedly, however, 12% of specimens were dot-blot positive but negative by PCR, and several specimens were discordant for type of HPV. Both HPV DNA tests agreed with cytology in 41% of women, and in 33% cytology was negative in the face of positive PCR and dot blot. Concordance of cytology with just PCR was 59%, and only with dot blot was 56%. Cervicography agreed with both HPV DNA tests in 41% of patients, with PCR alone in 55%, and with dot blot alone in 58%. Biopsy results did not reveal a strong correlation between histopathological criteria of HPV infection and detection of HPV DNA by either PCR or dot-blot hybridization. Thus the present study has shown that PCR is a slightly more sensitive indicator of HPV infection than dot-blot hybridization. Agreement of HPV DNA results with conventional screening tests was not strong, an observation consistent with many comparative studies by others. In conclusion, PCR is slightly more sensitive than DNA hybridization for detection of HPV, it can be used in conjunction with specimen collection by gentle lavage of the cervicovaginal epithelium, and the possibility remains that it may prove suitable as a screening test.

Colposcopy, punch biopsy, in situ DNA hybridization, and the polymerase chain reaction in searching for genital human papillomavirus (HPV) infections in women with normal PAP smears

To assess the prevalence of HPV infection in the genital tracts of women with normal PAP smears, a random series of 109 women was reexamined using colposcopy, a further PAP smear, and punch biopsies taken from the cervix (in 33 cases), vagina (212 cases), and anus (20 cases). The biopsy material was examined using routine histological investigations, in situ hybridization (ISH) with a 35S-labelled DNA probe cocktail (HPV 6, 11, 16, 18), and the polymerase chain reaction (PCR) to detect HPV DNA. Changes consistent with HPV infection were seen in 6.9% (18/262) of the biopsy specimens. Seven biopsy specimens (2.7%) from seven different women were found to contain HPV DNA using ISH. All of these ISH-positive lesions were diagnosed as morphologically characteristic HPV lesions: six flat condylomas and one papillary condyloma. Using PCR, the HPV DNA detection rate was highest in the cervical biopsy specimens (50%) and lowest (28.6%) in the anal biopsy specimens. A total of 35.5% of the 93 biopsy specimens studied using PCR contained HPV DNA. The commonest type was HPV 11 (54.5%), followed by HPV 18 (33.3%). Four of the nine biopsy specimens (44.4%) from colposcopically normal areas proved HPV DNA-positive using PCR. Of 17 biopsy specimens in which the histology was normal, seven were examined using PCR and three were DNA-positive. The discovery of HPV DNA using PCR in 32/92 of the biopsy specimens (34.8%) which had been found to be HPV DNA-negative when routine ISH was used is noteworthy. The results suggest that the light microscopy criteria currently used in diagnosing HPV infections are of no value in predicting latent HPV infections and that acetowhite staining is unable to distinguish between subclinical and latent infections on the one hand and changes unrelated to HPV on the other.

Cytologic diagnosis of human papillomavirus infection: spindled nuclei

The classic cytologic criteria, koilocytotic atypia and dyskeratocytosis, fail to identify most cases with colposcopic and histologic evidence of cervical condylomata. The purpose of this study was to identify a novel cytologic diagnostic criterion, spindled nuclei, to predict the presence of human papillomavirus (HPV) infection of the cervical epithelium. Review of the hospital records of 100 consecutive cases with spindled nuclei on Papanicolaou smear identified 36 patients in whom a colposcopic examination and/or cervical biopsy had been performed between January 1, 1988, and March 31, 1989. Ninety-seven percent of these 36 cases were positive by colposcopy and 89% of the cases were positive by cervical biopsy for changes of condyloma or intraepithelial neoplasia. HPV DNA hybridization in situ was positive in 16 of 36 patients, and the probe for types 31/33/35 most often stained histologic sections showing condylomatous change without concurrent dysplasia. Electron microscopy of spindled nuclei showed evidence of HPV-type viral particles in the five cases examined.

Detection of human papillomavirus in reprocessed routine Papanicolaou smears by DNA hybridization

DNA dot blot hybridization was used for the detection of human papillomavirus (HPV) types 6, 11, 16, and 18 in reprocessed routinely collected Papanicolaou smears. DNA was extracted from the smears with alkaline lysis and applied onto a nitrocellulose filter. The specificity and sensitivity of the dot blot hybridization on reprocessed Papanicolaou smears were confirmed by Southern blot analysis of selected samples, using CaSki, SiHa cell lines as positive controls and HF 32 as negative controls. From 42 normal smears and 44 abnormal smears with koilocytosis present, 9 (21%) and 43 (98%), respectively, were positive for HPV 6/11/16 or 18. These results show that reprocessed Papanicolaou smears in combination with DNA hybridization have potential application in retrospective studies on the prevalence and distribution of HPV infection.

Prevalence of cervical dysplasia and HPV infection according to sexual behavior

A total of 165 uterine cervix smears from Venezuelan women were examined by cytological techniques to identify malignant and pre-malignant cervical changes, as well as to identify Human Papilloma Virus (HPV) DNA types 6, 11, 16, 18, 31, 33 and 35. Of these smears, 119 were from nonmonogamous women who participated in a cervical carcinoma screening program. In this group, HPV-DNA was detected by hybridization in 42 samples (35%) and cervical intraepithelial neoplasia (CIN) in 13 (11%). Forty-six monogamous aboriginal women were similarly studied and no evidence of abnormal cytology or HPV-DNA of the types studied here was found in any of them. In the non-monogamous group, age at first sexual intercourse and index of parity were not associated with cervical HPV infection and/or CIN. The rates of HPV infection, however, were significantly different between the two populations, confirming that sexual behavior involving multiple partners is associated with HPV infection.

Comparison between the polymerase chain reaction and slot blot hybridization for the detection of HPV sequences in cervical scrapes

Sixty-four women presenting with a single mildly abnormal smear were investigated for infection with human papillomavirus (HPV) type 16 using both slot blot hybridization and polymerase chain reaction (PCR) amplification. PCR was nearly three times more sensitive for the detection of HPV 16 DNA than slot blot hybridization. HPV 16 was not significantly associated with a risk of progression to CIN if PCR was used to screen for infection. Women who smoked were at significantly greater risk of progression to CIN than non-smokers.

Demonstration of multiple HPV types in normal cervix and in cervical squamous cell carcinoma using the polymerase chain reaction on paraffin wax embedded material

The prevalence of human papilloma virus (HPV) types 6, 11, 16 and 18 was investigated using the polymerase chain reaction on formalin fixed, paraffin wax embedded material in 19 cases of cervical squamous cell carcinoma and in 10 normal cervices. HPV DNA was detected in 16 of 19 carcinomas, with multiple types present in 11 of these. HPV 16 or 18, or both, were present in all cases in which HPV was shown. Six of 10 cases of normal cervix contained HPV; five of these contained two or more HPV types, including HPV 16 or 18, or both. This study shows the feasibility of using the PCR on paraffin wax embedded material and indicates a high rate of carriage of multiple HPV types in both normal and neoplastic cervix.

Epidemiology of human papillomavirus (HPV) infections and their associations with genital squamous cell cancer. Review article

Reliable assessment of the epidemiology of genital HPV infections is hamphered by a number of technical problems. Because of the lack of tissue-culture systems, methods based on morphological approaches (colposcopy, cytology and histopathology) play a central role in HPV diagnosis. Even DNA-hybridization techniques and the recently introduced DNA amplification with PCR are extremely difficult to standardize, and are thus subject to major interlaboratory variation. Further confusion in the field is created by the complex biological behaviour of HPV infections. As established by the long-term prospective follow-up study of over 500 women which has been running in Kuopio since 1981, clinical progression and regression are significantly related to the grade of the lesion at the time of diagnosis (p less than 0.00001, and p = 0.0005, respectively), as well as to the type of HPV (p = 0.0012). Most importantly, however, genital HPV infections seem to run an extremely fluctuating course, passage from manifest to subclinical or latent infection being frequently encountered in individual patients when examined at 6-month intervals over prolonged periods. This explains the significantly divergent prevalence figures reported in different series (ranging from 2% to 80%), which are completely dependent on the technique used to analyse the presence of HPV, i.e. whether a) PAP smear, b) biopsy, c) DNA hybridization, or d) PCR amplification. The first two are capable of disclosing only manifest (clinical) infections, the latter two also the latent ones. In an unselected population of 22-year-old Finnish females, the prevalence of clinical HPV infections was about 3 per cent, and the adjusted annual incidence was 8.0 per cent. According to estimates of the life-time risk, up to 79% of Finnish females will contract at least one HPV infection between the ages 20 to 79 years. When related to the long-term trends in invasive cervical cancer in Finland, it is evident that this 79% life-time risk of becoming HPV-infected or even the observed 15% clinical progression rate for HPV infections in the prospective follow-up study by no means signifies an identical risk of developing cervical cancer (i.e. 0.79 x 0.15 = 11%). It seems likely that in countries where mass-screening programmes exist (and precancer lesions are traced), the high prevalence of HPV infections is not necessarily reflected as an increased prevalence of invasive cervical carcinomas. The distinction of lesions at risk for malignant transformation from those regressing spontaneously will have major implications in therapeutic considerations of genital HPV infections.

Human papillomavirus type 31 infection of the uterine cervix in England

A total of 452 uterine cervical scrapes, from two centres in England, has been examined by dot blot hybridisation for the presence of human papilloma virus (HPV) types 6, 11, 16, 18 and 31. HPV DNA was found in 36.5% samples. Twenty-nine of the women were infected with more than one type. Of those with detectable HPV, 14.5% had HPV type 31 infections. This type appears to cause significant infection of the genital tract in England.

Human papillomaviruses: are we ready to type?

The issue of determining which human papillomavirus (HPV) is present in a clinical specimen (typing specimens for HPVs) is receiving attention because HPVs cause condyloma acuminata and are associated with the continuum of disease which ranges from dysplasia to invasive genital cancer. Morphological inspection of precancerous lesions is not sufficient to determine which lesions will progress and which will not. A number of research tools based primarily on deoxyribonucleic acid hybridization have been developed. These permit identification and typing of HPV in genital tract scrapings or biopsies. Some HPV types (e.g., HPV-16 and HPV-18) have been identified in high-grade dysplasias and carcinomas more commonly than other types (e.g., HPV-6) and have been designated "high risk" types for cervical cancer. Thus, the question arises whether HPV typing would improve patient management by providing increased sensitivity for detection of patients at risk or by providing a prognostic indicator. In this review, the available typing methods are reviewed from the standpoint of their sensitivity, specificity, and ease of application to large-scale screening programs. Data implicating HPVs in the genesis of genital tract cancers are reviewed, as is the association of specific HPV types with specific outcomes. We conclude that there is currently no simple, inexpensive assay for HPV types, although such assays may be developed in the future. Analysis of the typing data indicates that, while HPV types can be designated high risk and low risk, these designations are not absolute and thus the low-risk group should not be ignored. In addition, interpretation of the data is complicated by finding high-risk types in individuals with no indication of disease. Insufficient data exist to indicate whether knowledge of the presence of a given HPV type is a better prognostic indicator than cytological or histological results. Thus, more research is needed before it can be determined whether typing information will augment the method currently in use for deciding treatment regimen and whether it warrants widespread use.

Detection and typing of human papillomavirus infection of the uterine cervix by dot blot hybridisation: comparison of scrapes and biopsies

Paired scrapes and biopsies from 100 women attending a routine colposcopy clinic were examined by dot blot DNA hybridisation for infection with human papillomavirus (HPV) types 6/11, 16, 18, and 31; 51% of the scrapes and 50% of the biopsies were positive for HPV infection. Scrapes detected more HPV 18 (10% vs. 2%, P = less than 0.05) and HPV 31 (7% vs. 3%, not significant) than did the biopsies, but biopsies detected more HPV 16 (42% vs. 33%, not significant). Comparison of the results for each patient revealed that the correlation between scrapes and biopsies was not very close: only 34 patients were HPV-positive by both sampling methods, whereas 67 were positive if the results were combined. This report discusses the implications of these findings.

Human papillomavirus coinfections of the vulva and uterine cervix

DNA filter in situ hybridisation (FISH) was used to determine the presence of human papillomavirus (HPV) genotypes 6/11, 16/18, and 31/33 in cell scrapes of the cervix and vulva of 128 women who had precancerous lesions and/or HPV infection of the cervix diagnosed by cytology, colposcopy, and histology. HPV-DNA was found in 87 (68%) vulval and 95 (74%) cervical cell scrapes, and in both the vulval and cervical scrapes of 73 (57%) women, but not in either the vulva or the cervix of 19 women (15%). Of the HPV-DNA-positive smears, the prevalence of the HPV types was 61% HPV 16/18, 14% HPV 6/11, 3% HPV 31/33, and 22% HPV 6/11 and 16/18. By contrast, HPV-DNA was not detected in the cervical smears of a control group of 35 women who were assessed to be free of cervical abnormalities by colposcopy and cytology. The epithelial response of the vulva and the cervix to application of 5% acetic acid was assessed by colposcopy and the results correlated with the presence of HPV genotypes. A possible or definite disorder of the cervix and vulva was detected by colposcopy in 95 (74%) and 96 (75%) of the 128 cases, respectively. The colposcopic assessment of the vulva was inconclusive in ten cases (8%), and only eight women (6%) were found to be free of both a vulval and cervical disorder. This study shows subclinical papillomavirus infections of the vulva frequently coexist with HPV infections and precancerous lesions of the cervix.(ABSTRACT TRUNCATED AT 250 WORDS)

Nucleic acid analysis by sandwich hybridization

One of the most significant achievements of the biochemist during the past two decades is the use to which immunologically based assays have been put in clinical diagnosis (Hood et al.: Immunology, 1984). The problem faced and surmounted by immunologists in effecting the transition from research tool to routine clinical assay bears a remarkable similarity to that confronting the molecular biologist today; i.e., how can nucleic acid hybridization, a technique of obvious potential (Meinkoth and Wahl: Anal Biochem 138:267-284, 1984; Syvanen: Med Biol 64:313-324, 1986; Matthews and Kricka: Anal Biochem 169:1-25, 1988), be modified in order to fulfill all necessary parameters of a routine diagnostic assay? There are several such requirements, and the importance placed on each depends on the objectives of the assay: the technique must be sensitive, specific, and reproducible. Other advantages would be cost-effectiveness, ease of manipulation, and amenability to automation. Ideally, the signal detection should be based on a non-radioactive system, because of the instability of probes labelled with isotopes like 32p, and the potential hazards involved in their handling and disposal. The sandwich hybridization for the analysis of nucleic acid sequences was first used in 1977 (Dunn and Hassell: Cell 12:23-36, 1977), but its potential as a diagnostic assay was not realized until 1983, when it was applied to the detection of adenovirus DNA in nasopharyngeal aspirates from children with acute respiratory infection (Ranki et al: Gene 21:77-85, 1983). It has since been modified and used not only for the detection of microbial infection (Virtanen et al.: Lancet i:381-383, 1983; Ranki et al.: Cur Top Microbiol Immunol 104:307-318, 1983; Lehtomaki et al.: J Clin Microbiol 24:108-111, 1986; Virtanen et al.: J Clin Microbiol 20:1083-1088, 1984; Palva and Ranki: Clin Lab Med 5:475-490, 1985; Polsky-Cynkin et al.: Clin Chem 31:1438-1443, 1985; Parkkinen et al.: J Med Virol 20:279-288, 1986; Palva: FEMS Microbiol Lett 28:85-91, 1985; Palva et al: FEMS Microbiol Lett 23:83-89, 1984; Zolg et al.: Mol Biochem Parasitol 22:145-151, 1987; Palva: J Clin Microbiol 18:92-100, 1983), but also for the analysis of nucleotide sequence variations (Langdale and Malcolm: Gene 36:201-210, 1985). We will discuss the development of the sandwich technique and the advantages it conveys over the more conventional nucleic acid hybridization formats, together with new developments which will ensure that it earns a place alongside immunoassay in the diagnostic laboratory.

Papillomavirus and cervical cancer: a clinical and laboratory study

It is now widely accepted that HPV types 16, 18, 31, and 33 are associated with the development of high grade intraepithelial neoplasia and malignant lesions in the cervix. On this basis, the identification of HPV types in cervical scrape samples has been advocated as a supplement to cytological screening tests. However, little is known of the distribution of the virus at different sites in the lower female genital tract or of how this distribution may change during the natural course of HPV infection. In this survey, HPV DNA dot hybridizations and, in some instances, Southern blot hybridizations with mixed HPV 6/11 and 16/18 probes were undertaken to detect HPV DNA in cervical scrapes and biopsies of the cervix, vagina, and vulva. A total of 92 women attending a Sydney hospital were screened: 59 of these patients had cervical disease, either invasive cervical carcinoma (CaCx) or cervical intraepithelial neoplasia (CIN), grades I-III. A group of 33 women who lacked evidence of cervical abnormalities served as controls. HPV DNA, predominantly type 16/18, was detected in the cervical biopsies of 96% of the CaCx patients, 80% of the CIN III patients, and 65% of the CIN I-II patients. In contrast only 9% of the cervical biopsies from the control group contained detectable HPV 6, 11, 16, or 18 DNA. A high proportion of the women with cervical abnormalities had evidence of concurrent vaginal and/or vulval papillomavirus involvement. The significance of these findings for routine screening and subsequent management of patients with HPV-associated cervical disease is discussed.

Sexual transmission of human papillomaviruses in heterosexual and male homosexual couples, studied by DNA hybridisation

The prevalence of human papillomavirus (HPV) 6, 11, 16, and 18 in 36 heterosexual couples and seven male homosexual couples with genital warts was investigated for evidence of sexual transmission of genital HPV. The prevalence of virus type and number of copies of viral genome equivalents/cell in the lesions were assessed, and the factors influencing transmission analysed. Our results show that HPV 6 and, to a lesser extent, HPV 11 were the types most readily transmitted, and that transmission appears to depend on the copy number and the duration and frequency of exposure.