Presence of human papillomavirus DNA sequences in cervical intraepithelial neoplasia

Definition of tumor antigens suitable for vaccine construction

The treatment of cancer with tumor vaccines has been a goal of physicians and scientists ever since effective immunization against infectious disease with vaccines was developed. In the past, major tumor antigens had not been molecularly characterized. Recent advances are, however, beginning to define potential molecular targets and strategies and this had evolved with the principle that T-cell mediated responses are a key target for approaches to cancer immunization. In addition, these antigens are not truly foreign and tumour antigens fit more with a self/altered self paradigm, compared to a non-self paradigm for antigens recognized in infectious diseases. Potential antigens include the glycolipids and glycoproteins (e.g. gangliosides), the developmental antigens (e.g. MAGE, tyrosinase, melan-A and gp75) and mutant oncogene products (e.g. p53, ras, and HER-2/neu). Innovations for construction of cancer vaccines are emerging from these advances in molecular immunology and cancer biology. While vaccines against infectious agents are models for vaccine development, there are clearly distinct considerations and problems associated with cancer vaccines. One of the focal issues in designing active cancer immunotherapy is that cancer cells are derived from normal host cells. Thus, the antigenic profile of cancer cells closely mimics that of normal cells. How the immune system identifies and destroys cancer cells is therefore crucial. Clearly, the ultimate goal of tumor vaccine design is the generation of antigen-specific vaccines. The recent success identifying molecularly defined tumor antigens opens up potentially novel strategies for this approach. Vaccine possibilities include purified proteins and glycolipids, peptides, cDNA expressed in various vectors, and a range of immune adjuvants. The molecular and structural definition of tumor antigens provides an opportunity for cautious optimism that we are entering an era when we will soon begin to recapitulate the success of immunization against infectious disease.

Relationships of cervical cytologies to selected variables among women attending a sexually transmitted disease clinic

A retrospective chart review was conducted for one year to determine cervical cytological abnormalities and their distribution among women attending a STD clinic, and to analyse cervical cytologies by STD diagnosis and history or presence of genital warts. Analysis was performed on 790 Pap smears. Most (60%) cytologies were benign. Prevalence of STD among CIN-1 cytologies (78%) was significantly higher (P = 0.02) than among benign cytologies (46%). Commonest cytologies presenting among youngest age groups were CIN-1/condyloma, CIN-1, CIN-2. Women with preceding or concurrent clinical HPV infection had significantly more HPV associated changes on cytology (P < 0.001) than women with no such history. The presentation of cytological abnormalities considered to be precursors to cervical cancer among sexually active young women demonstrates the importance of Pap smear testing of STD clinic populations.

Cancer vaccines

1993 represents the 100th anniversary of William Coley's first report of tumor regressions induced by immune system activation in response to bacterial toxins. While many subsequent cancer vaccine trials have yielded tantalizing results, active immunotherapy has not yet become an established modality of cancer therapy. Newer molecular vaccine approaches based on rational immunological principles have resulted in improved systemic antitumor effects in animal models. Ultimately the genetic definition of tumor-specific antigens will allow the development of targeted antigen-specific vaccines for cancer therapy.

Cancer vaccines

1993 represents the 100th anniversary of William Coley's first report of tumour regressions induced by immune system activation in response to bacterial toxins. While many subsequent cancer vaccine trials have yielded tantalizing results, active immunotherapy has not yet become an established modality of cancer therapy. Drew Pardoll reviews newer molecular vaccine approaches based on rational immunological principles that have resulted in improved systemic antitumour effects in animal models. Ultimately the genetic definition of tumour-specific antigens will allow the development of targeted antigen-specific vaccines for cancer therapy.

The detection of human papillomaviruses in cervical biopsies by immunohistochemistry and in situ hybridization

The presence of human papillomavirus (HPV) types 6, 16 and 18 in cervical biopsies can be detected by an immunoperoxidase technique using type-restricted monoclonal antibodies raised against fusion proteins representing the L1 major capsid proteins of these three HPV types. In a retrospective study (n = 54) we have used these antibodies and biotinylated DNA probes of HPV 6, 16 and 18 to detect and type HPV in formalin-fixed material from the cervix. The biopsies were classified histologically into normals, wart infections without dysplasia, cervical intraepithelial neoplasia (CIN) and squamous cell carcinomas. Antibody staining showed that 22% of all CIN was positive for HPV 16 and 40% of cervical warts were positive for HPV 6, 16 and 18. There was no HPV capsid protein detected in the normals and squamous cell carcinomas using these antibodies, whereas 25% of the tumours were positive for HPV 16 by in situ hybridization. Sections of cervical warts and CIN positive for HPV types by in situ hybridization were also positive by antibody staining which suggests that both techniques are detecting replicating virus. We feel these two techniques complement each other in detection and typing of HPV in cervical biopsies from patients with active disease.

Prevalence of occult human papillomavirus infection, determined by cytology and DNA hybridization, in heterosexual men attending a genitourinary medicine clinic

One hundred and five heterosexual men without evidence of clinical anogenital warts and attending a genitourinary medicine clinic were studied. Three separate specimens for cytology were taken from (i) the distal urethra including the perimeatal area, (ii) the penile shaft and glans penis including the sub-preputial area, and (iii) from the anorectal area using a proctoscope. Pooled specimens of exfoliated cells from these sites were also taken for the detection of human papillomavirus (HPV) by DNA hybridization. Twenty-eight (27%) of the men had cytological evidence suggestive of HPV infection. HPV genome was detected in 21 (20%) of the men by DNA hybridization and 95% of them were carrying HPV 16 genotype either alone or in combination with other genotypes. A total of 42 (40%) of patients had evidence of occult HPV infection using cytology and/or DNA hybridization techniques collectively. None of the epidemiological risk factors were significantly associated with occult HPV infection in this study. The significance of this high incidence of sexually transmissible HPV genomes, mostly HPV16 in the anogenital area of heterosexual men attending genitourinary medicine clinics requires further study.

Identification of T- and B-cell epitopes of the E7 protein of human papillomavirus type 16

There is strong evidence implicating human papillomavirus type 16 (HPV16) in the genesis of human genital cancer. Viral DNA has been identified in invasive carcinoma of the uterine cervix and in cell lines derived from cervical carcinomas. These sequences are actively transcribed, and translation products corresponding to the early (E)-region genes have been identified. The most abundant viral protein is the E7 protein, which has been shown to possess transforming activity for both established and primary cells. In addition, it has been shown to bind to a cellular tumor suppressor, the retinoblastoma gene product (pRb-105). In view of these properties, we have undertaken the immunological analysis of this protein and have identified four T-cell epitopes and three B-cell epitopes by using a series of overlapping peptides spanning the entire HPV16 E7 sequence. Two of the B-cell epitopes were recognized by antisera from mice with three different murine (H-2) haplotypes (k, d, and s) immunized with two different E7 fusion proteins and from Fischer rats seeded with baby rat kidney cells transformed by HPV16 E7 and ras. A third B-cell epitope was recognized by antisera from CBA mice seeded with HPV16 E7-expressing L cells. Two regions of the protein contain common B- and T-cell epitopes, one of which appears to be particularly immunodominant.

Clinical and virological associations between external anogenital warts and cervical HPV infection in an STD clinic population

To determine the significance of overt anogenital warts as indicators of human papillomavirus (HPV) infection of the cervix, 177 women attending a Sydney STD clinic were screened for evidence of cervical HPV infection using clinical criteria together with cytology and HPV DNA dot hybridization. HPV DNA probing was also performed on biopsies of 50 exophytic warts. A very high prevalence of both anogenital warts (40%), and of cervical HPV infection (58%) was indicated in this group of women. In the exophytic warts, HPV types 6/11 were most commonly detected, whereas the rates of detection of types 6/11 and 16/18 in the cervix were similar. Of the 87 women with evidence of cervical HPV infection, 57 (66%) had a history of either past or current overt exophytic anogenital warts; while the corresponding figure for the 90 women with no evidence of cervical infection was 45 (50%). Cytological evidence of dysplasia (CIN I-III) was detected in 13 (7%) of the cervical smears: of these, 4 were positive for HPV 16/18 only, 2 for 6/11 only and 4 for both 6/11 and 16/18.

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.

Immunoreactive alpha interferon in cervical flat koilocytic lesions and intraepithelial neoplasia

Immunocytochemical staining for alpha-interferon was carried out on cervical biopsy specimens showing non-condylomatous koilocytic atypia (n = 12) and cervical intraepithelial neoplasia (n = 18), both of which are associated with human papilloma virus (HPV) infection. Normal cervical tissue obtained from hysterectomy specimens was also assessed. Koilocytes were not immunoreactive for alpha interferon and keratinocyte staining was observed in only four cases of intraepithelial neoplasia. HPV infection alone does not therefore seem to induce the production of alpha interferon in cervical squamous epithelium. There was variable but, in some cases, prominent staining of cells in the stromal inflammatory infiltrate as well as intraepithelial cells which had morphological and immunocytochemical characteristics of Langerhans' cells. Alpha interferon immunoreactivity in Langerhans' cells is in keeping with derivation from the mononuclear phagocyte system and may be important in the host response to HPV infection.

Macrophage killing of human papillomavirus type 16-transformed cells

Papillomaviruses (HPV) are involved in proliferation of epithelial cells and are implicated in several human malignancies. We determined the capability of activated macrophages to exert cytostatic and/or cytolytic activities against HPV type 16 DNA-transformed cells. Both NIH-3T3 and A31-3T3 cells transformed with HPV DNA were susceptible to killing by activated macrophages; however, transformed and nontransformed cells were not susceptible to killing by soluble mediators. The HPV-transformed cells were as resistant as their nontransformed counterparts to recombinant TNF-alpha. These data suggest that the killing of the HPV-16-transformed 3T3 cells by macrophages occurred by a mechanism independent of TNF-alpha.

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.

Comparison of human papillomavirus type 1 serotyping by monoclonal antibodies with genotyping by in situ hybridization of plantar warts

Thirty plantar warts were analyzed for the presence of HPV-1 type-specific and PV genus-specific capsid antigens by immunofluorescence (IF) using monoclonal and polyclonal antibodies and type-specific HPV-1 DNA employing in situ hybridization methods. Fifteen of 30 plantar warts were positive by IF for PV genus-specific structural viral antigens. Thirteen of the 15 productively infected plantar warts expressed intranuclear HPV-1 type-specific capsid antigens and viral DNA, which were detected in the same distribution in each individual wart. The 2 productively infected plantar warts that did not react with HPV-1 type-specific MoAbs did not react with HPV-1 type-specific DNA by in situ hybridization. Thus, serotyping of HPV-1 capsid antigens by monoclonal antibodies is concordant with genotyping of HPV-1 viral DNA by in situ hybridization in productively infected plantar warts.

Inhibition of proliferation of lines derived from human cervical carcinomas by cytotoxic drugs and by recombinant interferons

The authors studied the effects of recombinant interferons (IFN), doxorubicin, and cisplatin against three cell lines derived from human epidermoid cervical carcinomas. These lines were SW 756, containing the genome of human papillomavirus (HPV) type 18, and CaSki and SiHa, containing HPV type 16. IFN-gamma suppressed the growth of all three lines, with a plateau in inhibitory effect beyond a concentration of 1000 units/ml. IFN-alpha was effective in this regard only against SW 756. In this line, the two IFNs together inhibited cell replication to a greater extent than the maximal effect of either IFN alone. Doxorubicin exerted a dose-dependent cytotoxic effect against all the lines, while cisplatin exhibited cytotoxicity only against SW 756. Doxorubicin and IFN-gamma, when used together, acted synergistically against CaSki and SiHa, and in an additive manner against SW 756.

Papillomavirus. Effects upon mother and child

Papillomaviruses are widespread, sexually transmitted agents with an increasing prevalence. They are associated with a significant risk of genital carcinoma in infected women. Because they can be transmitted to the fetus before or during birth, they are also a risk to the infant born to an infected woman. Laryngeal HPV infections, while presumably much less prevalent than genital tract infections, are associated with a high degree of morbidity and a significant degree of mortality when they cause laryngeal papillomas. Therefore, transmission of these viruses to the fetus is a major problem. Much more information regarding mode of transmission and possible cure for this infection is needed in order to reduce the risk of laryngeal papillomatosis in infants in the future.

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.

Risk factors in the development of cervical intraepithelial neoplasia in women with vulval warts

Of 59 women referred with vulval warts whose cervices were assessed colposcopically for the presence of cervical intraepithelial neoplasia (CIN) before local treatment of the wart lesions, 17 had histologically proved CIN, 12 had histologically proved cervical wart virus infection, and 30 had abnormality on colposcopy or cytology. Seven of the 17 with CIN had no abnormality on cervical cytology. No differences in sexual behaviour, smoking habit, or oral contraceptive use were seen between women with CIN and those with no cervical abnormality. Viral DNA typing of the vulval lesions was carried out, but there were no differences in the distribution of viral types between the three different histological groups. Of the 30 women with no abnormality at the initial visit, 23 were followed up colposcopically and cytologically for one to two years. Three of them developed CIN after adequate treatment of the vulval lesions despite the absence of cervical abnormalities on colposcopy at the time of treatment. Studying the known factors linked with CIN failed to show why some women with vulval warts develop CIN, even after treatment of the warts, and others do not. The large number of false negative results on cervical cytology in our patients suggests that women presenting with vulval warts should be screened colposcopically in the first instance. Close follow up of women whose warts are treated and who are thought to have no cervical abnormality at that assessment is essential.

Cancer of the cervix and the papilloma viruses

Squamous cancer of the cervix depends upon infection by Human Papilloma Virus (HPV), of which there are many strains. Some are more dangerous than others and they appear to compete with each other for "territory". The prospective use of vaccines and antiviral agents for HPV infection could disturb the balance of this ecosystem. This study derives the expressions for the prevalences of the different strains at equilibrium. The important parameters of these expressions are 1) the rate of change of sexual partner, 2) infectiousness on contact, and 3) the rates at which an infectious/immune phase decays to a non-infectious/immune phase, and then towards partial or full susceptibility to re-infection. The responses to changes in these parameters are investigated. Analysis shows that the balance between competing strains is locally and precariously stable; it can survive moderate inter-strain variations of the transmission and decay parameters; but larger differences, whether natural or artificially induced, can result in the rapid elimination of the disadvantaged strain. This might be exploited in a preventive programme. Conversely, if a harmless strain were eliminated, the harmful strains would fill the territorial gap, and the incidence of cervical cancer might increase.

DNA hybridisation of cervical scrapes: comparison with cytological findings in Papanicolaou smears

One hundred and sixty four cervical scrapes were taken over 26 months from 143 women aged 17 to 53 years, using an Ayre spatula. A smear was prepared from each sample for Papanicolaou staining and for cytological examination for evidence of human papillomavirus (HPV) infection. The cells remaining on the spatula were harvested for DNA analysis. These samples were probed for HPV 6, 16, and 18 and the results of DNA hybridisation and cytology were compared. Cytological changes of HPV (anucleate keratinised and keratinised squamous cells, koilocytic change and dyskeratosis, or multinucleation, or both) were detected in 103 (72%) of the samples where HPV DNA was detected; koilocytic changes were present in only 67 (48%). It is concluded that screening for a range of viral changes is a more sensitive method of detecting HPV infection than screening for koilocytic change alone.

Detection of DNA of human papillomavirus types 6/11 and 16/18 in cell scrapings of the uterine cervix by filter in situ hybridisation. Correlation with cytology, colposcopy and histology

The application of filter in situ hybridisation (FISH) to detect the presence of the DNA of human papillomavirus genotypes 6/11 and/or 16/18 in cell scrapings of the uterine cervix of 248 women in Western Australia is described. The results obtained by FISH are related to cervical dysplasia as assessed by cytology, colposcopy and histology. The detection of HPV infection was more sensitive and specific by FISH than by either histological/cytological evidence of an HPV cytopathic effect (koilocytosis) or immunohistochemical staining for HPV capsid antigen using antiserum against genus specific antigen of the bovine papillomavirus. Viral DNA was detected by FISH in 65% of women with atypical cytology and of the HPV positive cases, 68% were HPV 16/18, 22% HPV 6/11 and 10% of mixed types. HPV-DNA was detected in the cervical smears of 16 women who also had HPV capsid antigen (HPV-Ag) in their cervical biopsies; HPV 6/11 was found in 4 cases and HPV 16/18 in 12 cases. The relative frequency of the HPV-Ag positive cases decreased markedly from 44% to 4% with an increase in the severity of cervical dysplasia. By comparison, the percentage of HPV-DNA positive cases remained relatively constant between 70% and 80% for all 3 categories of dysplasia. Of these, the percentage of HPV 6/11 positives decreased slightly with an increase in the severity of dysplasia as assessed by either cytology or histology, whereas the percentage of HPV 16/18 positive cases was relatively constant. HPV-DNA was found in cervical smears of 11 of 48 (23%) women who were diagnosed colposcopically to have atypical transformation zone of the cervix. In 138 women with an atypical transformation zone, 96 (70%) were found to have HPV-DNA with HPV 16/18 contributing to 83% of the HPV positive cases. All four genotypes of HPV were found to be associated with the colposcopic morphology of mosaicism (26 cases) but only HPV 16/18 was found in 12 HPV-DNA positive cases associated colposcopically with punctation and an atypical transformation zone. The detection and typing of HPV-DNA in cell scrapings by FISH is a relatively fast and non-invasive procedure which complements cytology, colposcopy and histology and should be useful in further studies of the natural history of different HPV infections and their role in cervical cancer.

Demonstration of papillomavirus structural antigen in human urinary bladder neoplasia

Clear cells showing characteristic features of koilocytotic atypia were found in 41 (82%) of 50 paraffin sections of urinary bladder tumour. Papillomavirus common structural antigen was detected in seven (14%) of the samples using an avidin-biotin peroxidase staining technique. The results suggest a role for the human papillomavirus in the aetiology of urinary bladder neoplasia.

DNA hybridization of cervical tissues

The increasing frequency of cervical neoplasia among younger women and the increased invasiveness of these tumors has led to a considerable growth in research into this disease. Conventional methods (epidemiology, cytology, and immunology), while being extremely useful, also have significant limitations. Recent advances in techniques for the manipulation of DNA now make it possible to analyze tissues for the presence of viral genomes. This review introduces these techniques and describes their application to the search for herpes simplex virus and human papillomavirus sequences in cervical tissue. The significance of the findings both for the mechanism of transmission of the disease, and also the consequences for early detection and hence more successful treatment, are also discussed.

Nucleic acid probes in clinical microbiology

The infectious disease applications of nucleic acid probe have been described. In addition, the basic procedures of nucleic acid probe technology have been discussed, as have the factors affecting implementation of probe technology in diagnostic laboratories. Despite the questions raised, nucleic acid probes will become part of the diagnostic laboratory in the near future. Commercial interests are developing and marketing new probes, reagents, and kits which will expedite the employment of this technology. High-volume reference laboratories will first use probes as part of a battery of tests which will include ELISA and monoclonal antibody methods. In all probability, probes will replace methods: that have proven to be ineffective, difficult, or costly such as culturing for some enteric pathogens and Legionella, that require long incubation periods, such as mycobacteria, or that have high costs and low yields, such as virology.

Occurrence of HPV genomes in penile smears of healthy men

Penile smears of 530 males without any clinically detectable genital papillomavirus infection were subjected to molecular in situ hybridization on filters with different 32P-labeled HPV-DNAs. HPV genomes were identified in 31 cases (5.8%). Eight smears reacted with HPV 6/HPV 11 DNA and 5 specimens with HPV 16 and HPV 18 DNA exclusively; in 18 cases HPV 6/HPV 11 and HPV 16/HPV 18 were found in coexistence. With regard to the different age groups, HPV-DNA was found in only 1.7% of smears obtained from persons over 35 years of age, while 7.9% of the samples from men aged 15 to 35 gave positive results. This age distribution indicates that the occurrence of HPV genomes in epithelial cells of the glans may be due to infections by sexual contact rather than to reactivation of persisting viruses.

Human papillomavirus infections in a group of renal transplant recipients

One hundred and twenty renal transplant recipients were investigated. Fifty-eight (48%) were found to have warts, 13 (11%) keratoses and six (5%) to have, or recently to have had cancers. The longer the time of immunosuppression, the greater the prevalence of warts; of those patients who had had their transplant for at least 5 years, 87% had warts. Those with a graft survival time of 10 years or more are at special risk of warts, keratoses and malignancy. Five (10%) of 50 women had genital warts, four of whom had internal lesions (vaginal, cervical or anal) and one developed a carcinoma of the vulva. These findings indicate the advisability of colposcopy for all female renal transplant recipients, a high risk group. Eighty-eight specimens from 42 patients were examined by DNA restriction enzyme analysis and cross hybridization for the presence and type of human papillomavirus (HPV). HPV DNA was detected in 66% of the warts examined, HPV2 and HPV4 occurring most often and HPV1 and HPV3 only infrequently. In sequential specimens from common hand warts of one individual, an HPV was found which could not be precisely identified but was related to HPV4. HPV16 was detected in a vaginal wart from one patient and an HPV6-related virus in a vulval wart of another. HPV DNA of an unknown type was demonstrated in one of 11 keratoses examined. With the probes used to examine the few samples of skin cancers available, HPV16 was found in a squamous cell carcinoma of the vulva, and faint bands from an unidentified type of HPV were detected in two squamous cell carcinomata from a patient's hand. One woman had plaque lesions morphologically and histologically resembling those found in epidermodysplasia verruciformis (EV). HPV5 was identified in these lesions. This is only the third reported case of HPV5, previously thought to be unique to EV, in a renal transplant recipient.

Human papillomavirus infection of the uterine cervix of women without cytological signs of neoplasia

One hundred and six patients were studied whose cervical smears showed only non-specific inflammatory changes. Screening for genital pathogens yielded only a few positive cases. Histological examination of biopsy specimens taken by colposcopically directed tissue sampling showed cervical intraepithelial neoplasia in 13 of the women (12.3%). Deoxyribonucleic acid (DNA) hybridisation techniques were used to detect human papillomavirus, which was found in 24 patients (22.6%). In a second group of 104 patients with normal cervical cytology tissue biopsy samples were obtained and examined histologically but in no case was cervical intraepithelial neoplasia found. On DNA hybridisation, however, 12 patients (11.5%) were found to be positive for human papillomavirus. In this group finding human papillomavirus DNA was usually associated with a columnar ectopy. An association between human papillomavirus type 16 DNA and both cervical intraepithelial neoplasia and cervical cancer is well established. In this study it was type 16 which occurred most frequently in both groups.

The effect of interferon on human papillomaviruses associated with cervical intraepithelial neoplasia

A double-blind, placebo-controlled, trial of leucocyte interferon showed that, contrary to previous reports, interferon had no significant effect on cervical intraepithelial neoplasia (CIN) when applied topically in a gel. DNA hybridization of cervical scrapes was used to monitor the effect of interferon on the human papillomaviruses (HPV) associated with CIN. There was, however, no significant difference in the expression of HPV 6 or 16 in the cervical epithelium of patients treated with interferon compared with those given a placebo. By using superficial cells scraped from the surface of the cervical epithelium as a source of DNA for viral studies, we were able to investigate the relation between HPV and CIN without interfering with the natural history of the disease. HPV 16 was detected in lesions which persisted while HPV 6 only was detected in one lesion that regressed. Regression was clearly associated with reduction in the number of copies of viral DNA per cell in this case. Dual infection with HPV types 6 and 16 were recorded in two patients with persistent lesions. In one patient, hybridization studies indicated that infection with HPV 16 could have occurred after infection with type 6 was established, and it is postulated that this may have changed the nature of the cervical lesion.

Association between anorectal dysplasia, human papillomavirus, and human immunodeficiency virus infection in homosexual men

Cells from the anorectal mucosa of 61 homosexual men were examined microscopically for evidence of papillomavirus infection and dysplastic changes. There was cytological evidence of dysplasia with concomitant features of human papillomavirus (HPV) infection on at least one occasion in 24 men and of papillomavirus infection without dysplasia on at least one occasion in a further 26: dysplasia was present for over one year in 9 of 14 men who were re-examined. Dysplasia was associated with a history of anal warts, frequent receptive anal intercourse, presence of serum antibody to human immunodeficiency virus (HIV), and immune dysfunction as judged by a low CD4/CD8 ratio, but not with the lifetime number of sexual partners. The association of longlasting dysplasia with anti-HIV was independent of the association with immune dysfunction. Thus infection of anorectal mucosal cells with papillomavirus seems to be frequent among homosexual men and may predispose to dysplasia.

Sexual factors, venereal diseases, and the risk of intraepithelial and invasive cervical neoplasia

The relation between major indicators of sexual habits (age at first intercourse and total number of sexual partners), history of selected venereal diseases, and cervical neoplasia was investigated using data from a case-control study of 206 cases of cervical intraepithelial neoplasia compared with 206 age-matched outpatient controls, and of 327 cases of invasive cancer compared with 327 control subjects in hospital for acute conditions unrelated to any of the established or suspected risk factors for cervical cancer. The relative risks increased with decreasing age at first intercourse and increasing number of sexual partners both for intraepithelial and for invasive cancers. The effects of these two variables were independent, since they were only marginally affected by reciprocal adjustment, or by allowance for several other identified potential distorting factors. The negative association with age at first intercourse was particularly strong in the case of invasive cancers, with risk estimates over five-fold elevated for women reporting their first intercourse before age 18 compared with those aged over 22 years. This relation might be discussed in terms of multistage models of carcinogenesis, which predict that the incidence of epithelial carcinomas is a function of duration of exposure. In fact, when age was allowed for, the relative risks of cervical neoplasia were positively and strongly related with the total duration of the interval between age at diagnosis/interview and age at first intercourse. Clinical histories of several sexually transmitted diseases were positively associated with the risk of intraepithelial neoplasia. In particular, genital warts were reported by nine cases but no control subject. No such association, however, emerged for invasive carcinomas. Thus, the current findings confirm that, although intraepithelial neoplasia and invasive cervical cancer appear to share several important epidemiological features, the specific (infectious) agents implicated in dysplastic lesions probably differ to some extent from those causing invasive cancer.

DNA sequences of human papillomavirus types 11, 16, and 18 in lesions of the uterine cervix in the west of Scotland

Punch biopsy specimens of the cervix were examined both histologically and for the presence of human papillomavirus (HPV) DNA sequences. The presence of HPV DNA sequences was sought with the Southern blot technique using radioactively labelled HPV-6, 11, 16, and 18 DNA probes, both together and separately. Twenty six biopsy specimens were examined. Histological examination showed cervical intraepithelial neoplasia grade 2 or 3 in 16 specimens, viral changes (koilocytosis) in four, and inflammation or a normal appearance in three. Eleven specimens were negative for HPV DNA sequences, 10 contained HPV-16 DNA, four contained HPV-18 DNA, and one contained both HPV-18 and HPV-11 DNA. Episomal HPV-16 DNA was detected in one case of cervical intraepithelial neoplasia grade 3 and in five cases of cervical intraepithelial neoplasia grade 2/3 with koilocytosis; and episomal HPV-18 DNA was found in two specimens classed as cervical intraepithelial neoplasia grade 2/3, one of which also contained HPV-11 DNA, and in one specimen that showed viral changes alone. Integrated HPV DNA was found in six specimens (four with HPV-16 DNA and two with HPV-18 DNA), including two cases of chronically inflamed cervix with no histological evidence of viral infection or cervical intraepithelial neoplasia. Detection of viral DNA in early lesions may identify patients at risk of malignant progression. This is the first report of HPV-18 DNA in cervical intraepithelial neoplasia in Scotland.

Clinical applications of gene probes in human genetic disease, malignancy, and infectious disease

Recent developments in recombinant DNA technology have made possible the production of gene probes consisting of cloned gene segments, cloned segments of DNA linked to genes, and synthetic gene fragments. Several methods have been developed by which these probes may be used for the diagnosis of human disease. This technology has been outstandingly successful for prenatal diagnosis and carrier detection in many genetic diseases. These methods have also been successfully applied to the analysis of human malignancies, by providing for the determination of cell lineage and clonality in lymphoid neoplasms. Finally, these methods have shown potential for rapid and sensitive diagnosis of some infectious diseases.

Human papillomavirus types 16 and 18 in carcinomas of the penis from Brazil

Human papillomavirus (HPV) type-16 DNA sequences were found in 26/53 (49%) and HPV type-18 in 5/53 (9%) of penile cancers. In only one specimen was HPV18 found on its own. HPV16 sequences were integrated into the host cell chromosomes although some monomeric and oligomeric free forms of DNA were detected in a few tissues. HPV18 was, as far as detectable, free and unintegrated in all tissues tested. HPV16 DNA was also detected in 40% of cases of carcinoma of the cervix in 19 women from the same social groups as the males. The viral DNA in the female cases was a mixture of integrated and free forms. The DNA binding protein (ICSP 11/12) of herpes simplex type 2 (HSV2) was not detected in 10 penile cancers tested with a monoclonal antibody.

Human papillomavirus types 6 and 16 in multifocal intraepithelial neoplasias of the female lower genital tract

Five women with multifocal intraepithelial neoplasia of the lower genital tract were investigated for the presence of human papillomavirus (HPV) infection by the method of DNA-DNA hybridization which detects the viral DNA. The DNA sequences of HPV types 6 and 16 were detected in each of the five patients and in each of the areas biopsied: cervix, vagina and vulva. DNA sequences of both viral types were also found in vulval intraepithelial neoplasia grades I-III and in cervical intraepithelial neoplasia grades I and III. The detection of HPV DNAs in multifocal lesions suggests a possible common aetiology for the lower genital tract intraepithelial neoplasias.

Prevalence of human papillomavirus type 16 DNA sequences in cervical intraepithelial neoplasia and invasive carcinoma of the cervix

The frequency of human papillomavirus (HPV) type 16 in premalignant and malignant lesions of the cervix was investigated and compared with the detection of HPV type 6. In cervical intraepithelial neoplasia (CIN) grades I-III HPV 6 was detected in 28% and HPV 16 in 62% of patients whereas 90% of malignant lesions contained HPV 16 only. In the CIN lesions there was an increase in HPV 16 detection as the severity of disease increased while the level of detection of HPV 6 decreased. Only three (18%) of the cervices that were colposcopically and histologically normal contained HPV genomes; although two of these three women had either a history of genital warts or a sexual partner with penile warts.

Association of HPV with human genital tumors

Human papillomaviruses (HPV) are clearly responsible for the induction of genital lesions like condylomata acuminata, bowenoid papules, and flat condylomas. Moreover, the DNA of particular virus types (HPV 16 and 18) is found in a substantial number of invasively growing squamous cell carcinomas of the genital tract, suggesting an etiologic involvement of these viruses in tumor development. Since HPV 16 and 18 as well as other papillomaviruses (HPV 6 or 11) usually present within the benign genital warts can be found in dysplastic lesions of the uterine cervix known as putative precancerous lesions, determination of the virus type might be of diagnostic relevance. Since no type-specific serologic reagents are available, viruses can be identified by nucleic acid hybridization using radioactively labeled HPV DNAs that have been molecularly cloned as probes.

Management of condyloma acuminatum

This article describes an approach to the evaluation and treatment of condyloma acuminatum (anogenital warts) that is based on the results of new clinical research on the biology of the human papillomavirus. A more extensive diagnostic protocol, including routine cervicovaginal examination and Papanicolaou smear, is proposed for female patients because of the close association of genital human papillomavirus infections with cervical carcinoma. Two highly effective therapies, cryosurgery and carbon dioxide laser photocoagulation, are described and compared with older regimens. Recent developments in immunotherapy for resistant condyloma acuminatum are also discussed.

Papillomaviruses: their possible role in oral disease

Papillomaviruses are ubiquitous DNA viruses that are epitheliotropic and produce a range of epithelial neoplasms, both benign and malignant, in animals and man. Human papillomaviruses are associated with a variety of rare and uncommon oral lesions, and there has been increasing suspicion that they may be implicated also in some premalignant and malignant oral lesions.