Human papillomavirus genotype distribution in genital warts among women in Harare-Zimbabwe.

This study aimed to determine the prevalence of HPV genotypes in genital warts among women in Harare, Zimbabwe. Women aged 18-45 years attending gynaecology and genitourinary clinics with a clinical diagnosis of genital-warts were recruited. HPV-DNA was extracted from tissue biopsies. HPV-DNA testing and typing was done by Southern Dot Blot Hybridisation. A hundred samples from 100 women were analysed. Median age of participants was 30.3 years (range 18-45 years). Seventy-eight percent of participants were HIV infected. HPV prevalence was 98%. Low risk genotypes predominated at 86% prevalence. The most prevalent genotypes were 11 (47%), 6 (42%) and 16 (14%). This is the first study on HPV genotype distribution among women with genital warts in Zimbabwe. The high prevalence of HR-HPV 16 in clinically benign lesions shows that warts should have histological analysis to exclude pre-malignancy and malignancy.Impact statementWhat is already known on this subject? Genital warts (GWs), also known as condylomata acuminata (EAC), are a clinical manifestation of persistent infection with 'low risk' or non-oncogenic HPV genotypes. HPV 6 and 11 are examples of low risk genotypes, and both are associated with 90% of GWs. Data on HPV genotypes causing genital warts in the population under study are scarce.What do the results of this study add? A high prevalence (98%) of HPV DNA in genital warts, confirms that the biopsied lesions were HPV related. Over and above the high prevalence of low risk HPV 11 (47%) and HPV 6 (42%), the women had 14% prevalence of HPV 16, an oncogenic genotype, in genital warts. Seventy-eight percent of the participants were HIV infected. The HIV infected women had a 33.3% prevalence of HR-HPV as compared to the 15.8% prevalence in the HIV uninfected women.What are the implications of these findings for clinical practice and/or further research? The population under study will benefit more if an HPV vaccine that includes anti-HPV 6 and 11 is used. The high prevalence of the HR-HPV in apparently benign lesions shows that warts should have histological analysis to exclude vulvar cancer and vulvar intraepithelial neoplasia. All women presenting with genital warts should be offered an HIV test.

Carcinogenesis Associated with Human Papillomavirus Infection. Mechanisms and Potential for Immunotherapy.

Human papillomavirus (HPV) infection is responsible for approximately 5% of all cancers and is associated with 30% of all pathogen-related cancers. Cervical cancer is the third most common cancer in women worldwide; about 70% of cervical cancer cases are caused by the high-risk HPVs (HR HPVs) of genotypes 16 and 18. HPV infection occurs mainly through sexual contact; however, viral transmission via horizontal and vertical pathways is also possible. After HPV infection of basal keratinocytes or ecto-endocervical transition zone cells, viral DNA persists in the episomal form. In most cases, infected cells are eliminated by the immune system. Occasionally, elimination fails, and HPV infection becomes chronic. Replication of HPVs in dividing epithelial cells is accompanied by increased expression of the E6 and E7 oncoproteins. These oncoproteins are responsible for genomic instability, disruption of the cell cycle, cell proliferation, immortalization, and malignant transformation of HPV-infected cells. Besides, E6 and E7 oncoproteins induce immunosuppression, preventing the detection of HPV-infected and transformed cells by the immune system. HPV integration into the genome of the host cell leads to the upregulation of E6 and E7 expression and contributes to HPV-associated malignization. Prophylactic HPV vaccines can prevent over 80% of HPV-associated anogenital cancers. The vaccine elicits immune response that prevents initial infection with a given HPV type but does not eliminate persistent virus once infection has occurred and does not prevent development of the HPV-associated neoplasias, which necessitates the development of therapeutic vaccines to treat chronic HPV infections and HPV-associated malignancies.

Human papillomavirus-related oropharyngeal cancer in the HIV-infected population.

Human papillomavirus (HPV) is a common sexually transmitted virus and an important etiologic factor in head and neck cancers. HIV-infected individuals are at increased risk of developing oropharyngeal cancers (OPC) compared with the general population. HPV-positive OPC are also increasingly a significant cause of morbidity and mortality for HIV-infected individuals in the era of effective combination antiretroviral therapy. The epidemiology and natural history of oral HPV infection have not been well established, but it appears that oral HPV infection is less common than anal infection, and more common among HIV-infected persons than the general population. Prevention of OPC is therefore increasingly important in HIV-infected individuals. Although not demonstrated in randomized controlled trials, HPV vaccination may prevent oral HPV infection as well. The focus of organized HPV cancer prevention programs should include prophylactic HPV vaccination to reduce the burden of high-risk HPV and low-risk HPV types who have not yet been exposed.

Factors associated with prevalent abnormal anal cytology in a large cohort of HIV-infected adults in the United States.

BACKGROUND: The prevalence of and risk factors for abnormal anal cytology among men and women with human immunodeficiency virus (HIV) infection have not been extensively investigated. METHODS: The Study to Understand the Natural History of HIV and AIDS in the Era of Effective Therapy (SUN study) is a prospective cohort study of HIV-infected patients in 4 US cities. Baseline questionnaires were administered and anal samples for cytology and human papillomavirus (HPV) detection and genotyping were collected. RESULTS: Among 471 men and 150 women (median age, 41 years), 78% of participants were receiving combination antiretroviral therapy, 41% had a CD4(+) cell count of ≥500 cells/µL, and 71% had an HIV RNA viral load of <400 copies/mL. The anal cytology results were as follows: 336 participants (54%) had negative results, 96 participants (15%) had atypical squamous cells, 149 participants (24%) had low-grade squamous intraepithelial lesions, and 40 participants (6%) had high-grade squamous intraepithelial lesions. In a multivariate analysis, abnormal anal cytology was associated with number of high-risk and low-risk HPV types (adjusted odds ratio [AOR] for both, 1.28; P < .001), nadir CD4(+) cell count of <50 cells/µL (AOR, 2.38; P = .001), baseline CD4(+) cell count of <500 cells/µL (AOR, 1.75; P = .004), and ever having receptive anal intercourse (AOR, 2.51; P < .001). CONCLUSION: HIV-infected persons with multiple anal HPV types or a nadir CD4(+) cell count of <50 cells/µL have an increased risk for abnormal anal cytology.

Esophageal verrucous carcinoma arising from hyperkeratotic plaques associated with human papilloma virus type 51.

Esophageal verrucous carcinoma is a rare variant of esophageal squamous cell carcinoma. We report a case of esophageal verrucous carcinoma associated with human papilloma virus (HPV) type 51. The patient had long-standing dysphagia and odynophagia, and white esophageal plaques showing hyperkeratosis on biopsy. At repeat endoscopy, the esophagus was covered with verrucous white plaques and areas of nodular mucosa with white fronds, with a distal 10-cm smooth mass protruding into the lumen. Biopsies demonstrated an atypical squamoproliferative lesion but no frank malignancy. HPV type 51 DNA was detected in endoscopic biopsy specimens by polymerase chain reaction. Because the size of the lesion favored an underlying verrucous carcinoma, our patient underwent minimally invasive esophagectomy with gastric pull-up and cervical anastomosis. The pathologic diagnosis was a well-differentiated esophageal verrucous carcinoma. One year after esophagectomy, the patient feels well and is free of disease. Although HPV DNA was not detected in the cancer tissue obtained at surgery, our case suggests an association between HPV type 51 and esophageal verrucous carcinoma. The clinical evolution in this case highlights the importance of endoscopic surveillance in patients with exuberant esophageal hyperkeratosis, and of definitive surgical resection when malignancy is suspected even if frank malignancy is not demonstrated on superficial biopsies.

Seroprevalence of HPV 6, 11, 16 and 18 and correlates of exposure in unvaccinated women aged 16-64 years in Puerto Rico.

BACKGROUND: To understand risk factors for HPV exposure in Puerto Rican women, we evaluated HPV 6, 11, 16, and 18 serology in women aged living in the San Juan metropolitan area. METHODS: As part of a cross-sectional study, a population-based sample of 524 HPV unvaccinated Hispanic women ages 16-64 years completed face-to-face and computer assisted interviews and provided blood and self-collected anal and cervical specimens. Serology used multiplex virus-like particle based-IgG ELISA and HPV DNA was detected with L1-consensus PCR. RESULTS: 32% and 47% were seropositive to HPV types included in the bivalent (16/18) and quadrivalent (6/11/16/18) vaccines, respectively. Type-specific seroprevalence was HPV6 - 29%, HPV11 - 18%, HPV16 - 23%, and HPV18 - 17%; seroprevalence was high in the youngest age-group (16-19: 26-37%). HPV seropositivity was associated with having ≥ 3 lifetime sexual partners (OR=2.5, 95% CI=1.7-3.9) and detection of anogenital HPV DNA (OR=1.8, 95% CI=1.2-2.6). CONCLUSIONS: The high cumulative exposure of HPV vaccine types 6/11/16/18 in this Hispanic population was influenced by factors related to HPV exposure through sexual behavior. High seroprevalence in the youngest age-group indicates early age of exposure to HPV in Puerto Rico, highlighting the need for HPV vaccination starting prior to age 16.

Characterization of in vivo expression of the human papillomavirus type 16 E4 protein in cervical biopsy tissues.

The role of human papillomavirus (HPV) proteins in the pathogenesis of cervical intra-epithelial neoplasia (CIN) and invasive cervical cancer is poorly understood. To characterize E4 protein expression in 49 paraffin-embedded cervical biopsies representing different histopathologic grades of disease, antibodies were elicited to a synthetic peptide corresponding to amino acids 20-34 of a protein predicted to be encoded by the HPV 16 E4 open reading frame. The E4 protein was detected throughout the spectrum of CIN, from CIN1 to CIN3. Expression was localized to the cell nucleus, primarily in the superficial layers of the squamous cervical epithelium. Ultrastructural studies showed that the E4 protein was organized into compact, intranuclear arrays 25-35 nm in diameter. E4 protein expression was also demonstrated in some histologically normal tissues containing HPV 16 DNA, but not in any of five cervical cancers containing HPV 16 DNA. These results suggest that E4 protein expression may precede development of light microscopic tissue abnormalities, that it may continue through the spectrum of CIN, and that expression of this protein may be reduced or terminated in invasive cancer. The function of this protein remains unknown, but its nuclear localization may be consistent with a role in viral maturation.

HPV vaccination of immunocompromised hosts.

It is well-established that immunocompromised people are at increased risk of HPV-related disease compared with those who are immunocompetent. Prophylactic HPV sub-unit vaccines are safe and immunogenic in immunocompromised people and it is strongly recommended that vaccination occur according to national guidelines. When delivered to immunocompromised populations, HPV vaccines should be given as a 3-dose regimen.

S100A8 triggers oxidation-sensitive repulsion of neutrophils.

The inflammatory response to tissue injury is a multi-faceted process. During this process, neutrophils migrate in the extravascular spaces, directed to the site of injury by chemical gradients generated by chemotactic molecules. S100A8, a protein associated with a wide variety of inflammatory conditions, is heavily over-expressed in association with inflammation. We hypothesized that human S100A8 possesses neutrophil-repelling properties that result in an anti-inflammatory effect in vivo. The chemotactic activity of S100A8 on neutrophils was tested in Transwell chemotaxis assays. Analysis of the data indicates that S100A8 causes a repulsion of peripheral neutrophils, an activity that S100A8 loses upon its oxidation. Using a mutant of S100A8 resistant to oxidation and consistent with the in vitro findings, we demonstrated that S100A8 causes a strong anti-inflammatory effect in the rat air-pouch model of inflammation in vivo. These data highlight a naturally occurring novel anti-inflammatory pathway and provide potential molecular targets for the development of novel anti-inflammatory therapeutics. Abbrevations: ethylene diamine tetraacetic acid (EDTA); limulus amoebocyte lysate assay (LAL); pertussis toxin (PTX); forward scatter (FSC); Interleukin-8 (IL-8); formyl-Met-Leu-Phe (fMLP); monocyte chemotactic protein 1 (MCP1).

Prevalence and risk factors for anal squamous intraepithelial lesions in women.

BACKGROUND: Anal cancers are thought to arise from squamous intraepithelial lesions in the anal canal, and women infected with human immunodeficiency virus-1 (HIV) may be at higher risk of anal cancer. Our aim was to determine the prevalence of human papillomavirus (HPV)-related abnormalities of the anal canal in women and to characterize risk factors for these lesions. METHODS: We evaluated HPV-related abnormalities in 251 HIV-positive and in 68 HIV-negative women. We completed physical examinations and obtained questionnaire data on medical history and relevant sexual practices. Univariate and adjusted relative risks (RRs) and 95% confidence intervals (CIs) were computed using the Mantel-Haenszel procedure and regression techniques. All statistical tests were two-sided. RESULTS: Abnormal anal cytology, including atypical squamous cells of undetermined significance, low-grade squamous intraepithelial lesions, or high-grade squamous intraepithelial lesions (HSILs), was diagnosed in 26% of HIV-positive and in 8% of HIV-negative women. HSILs were detected by histology or cytology in 6% of HIV-positive and in 2% of HIV-negative women. HIV-positive women showed increased risk of anal disease as the CD4 count decreased (P<.0001) and as the plasma HIV RNA viral load increased (P =.02). HIV-positive women with abnormal cervical cytology had an increased risk of abnormal anal cytology at the same visit (RR = 2.2; 95% CI = 1.4 to 3.3). Abnormal anal cytology in HIV-positive women was associated with anal HPV RNA detected by the polymerase chain reaction and by a nonamplification-based test (RR = 4.3; 95% CI = 1.6 to 11). In a multivariate analysis, the history of anal intercourse and concurrent abnormal cervical cytology also were statistically significantly (P =.05) associated with abnormal anal cytology. CONCLUSIONS: HIV-positive women had a higher risk of abnormal anal cytology than did HIV-negative women with high-risk lifestyle factors. These data provide strong support for anoscopic and histologic assessment and careful follow-up of women with abnormal anal lesions.

Cervicovaginal human papillomavirus infection in human immunodeficiency virus-1 (HIV)-positive and high-risk HIV-negative women.

BACKGROUND: Human papillomavirus (HPV) infection is associated with precancerous cervical squamous intraepithelial lesions commonly seen among women infected with human immunodeficiency virus-1 (HIV). We characterized HPV infection in a large cohort of HIV-positive and HIV-negative women participating in the Women's Interagency HIV Study to determine the prevalence of and risk factors for cervicovaginal HPV infection in HIV-positive women. METHODS: HIV-positive (n = 1778) and HIV-negative (n = 500) women were tested at enrollment for the presence of HPV DNA in a cervicovaginal lavage specimen. Blood samples were tested for HIV antibody status, level of CD4-positive T cells, and HIV RNA load (copies/mL). An interview detailing risk factors was conducted. Univariate and multivariate analyses were performed. RESULTS: Compared with HIV-negative women, HIV-positive women with a CD4+ cell count of less than 200/mm3 were at the highest risk of HPV infection, regardless of HIV RNA load (odds ratio [OR] = 10.13; 95% confidence interval [CI] = 7.32-14.04), followed by women with a CD4+ count greater than 200/mm3 and an HIV RNA load greater than 20,000 copies/mL (OR = 5.78; 95% CI = 4.17-8.08) and women with a CD4+ count greater than 200/mm3 and an HIV RNA load less than 20,000 copies/mL (OR = 3.12; 95% CI = 2.36-4.12), after adjustment for other factors. Other risk factors among HIV-positive women included racial/ethnic background (African-American versus Caucasian, OR = 1.64; 95% CI = 1.19-2.28), current smoking (yes versus no; OR = 1.55; 95% CI = 1.20-1.99), and younger age (age < 30 years versus > or = 40 years; OR = 1.75; 95% CI = 1.23-2.49). CONCLUSIONS: Although the strongest risk factors of HPV infection among HIV-positive women were indicators of more advanced HIV-related disease, other factors commonly found in studies of HIV-negative women, including racial/ethnic background, current smoking, and age, were important in HIV-positive women as well.

Detection of human papillomavirus DNA in anal intraepithelial neoplasia and anal cancer.

Forty anal paraffin-embedded tissue specimens from 24 subjects were studied for the presence of human papillomavirus (HPV) types 6, 11, 16, 18, 31, and 33, herpes simplex virus (HSV), Epstein-Barr virus, and cytomegalovirus DNA by using the polymerase chain reaction. These tissues ranged from histologically normal to invasive squamous cell carcinoma. HPV DNA was detected in the invasive anal cancer tissues of 11 of 13 subjects. HPV types were segregated by histopathological severity, with HPV 16 associated exclusively with high grade anal intraepithelial neoplasia and invasive cancer. HPV types 6 and 11 were associated with condyloma and low grade anal intraepithelial neoplasia. HPV DNA in situ hybridization studies confirmed the presence of HPV DNA in the invasive cancer tissues of 6 of 12 subjects. HPV DNA in these tissues was highly focal and primarily associated with invasive cell nests that demonstrated the greatest degree of squamous differentiation. HSV DNA was detected only in association with advanced disease, being found in the cancer tissues of 5 of 13 subjects, and in 3 of 4 subjects with high grade anal intraepithelial neoplasia, but was not detected by in situ hybridization. Epstein-Barr virus and cytomegalovirus DNA were not detected in the 40 tissue specimens. We conclude that HPV infection may play an important role in the pathogenesis of anal cancer. The association between HSV infection and high grade anal disease suggests that HSV infection may also play a role in disease progression.

Immunogenicity and safety of the 9-valent HPV vaccine in men.

OBJECTIVES: This study was designed to evaluate the immunogenicity and tolerability of a prophylactic 9-valent HPV (types 6/11/16/18/31/33/45/52/58) VLP (9vHPV) vaccine in young men 16-26 years of age in comparison to young women 16-26 years of age (the population that was used to establish 9vHPV vaccine efficacy). Safety and immunogenicity data from this study will be used to bridge 9vHPV vaccine efficacy findings in 16-26 year old women to 16-26 year old men. METHODS: This study enrolled 1106 heterosexual men (HM) and 1101 women who had not yet received HPV vaccination. In addition, 313 men having sex with men (MSM) were enrolled and were evaluated separately for immunogenicity because previous results showed that antibody responses to quadrivalent HPV (types 6/11/16/18) VLP (qHPV) vaccine were lower in MSM than in HM. All subjects were administered a 3-dose regimen (Day 1, Month 2, Month 6) of 9vHPV vaccine. Serum samples were collected for anti-HPV assays. Safety information was collected for ∼ 12 months. RESULTS: The geometric mean titers (GMTs) for HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 for HM were non-inferior to those of women at Month 7. For all vaccine HPV types, Month 7 GMTs were numerically lower in MSM than in HM. Over 99.5% of subjects were seropositive at Month 7 for each vaccine HPV type. Administration of 9vHPV vaccine to both 16-26 year old men and women was generally well tolerated. CONCLUSIONS: These results support bridging the efficacy findings with 9vHPV vaccine in young women 16-26 years of age to men 16-26 years of age.

High incidence of anal high-grade squamous intra-epithelial lesions among HIV-positive and HIV-negative homosexual and bisexual men.

OBJECTIVE: The incidence of anal cancer among homosexual men exceeds that of cervical cancer in women, and HIV-positive homosexual men may be at even higher risk than HIV-negative men. Cervical cancer is preceded by high-grade squamous intra-epithelial lesions (HSIL) and anal HSIL may similarly be the precursor to anal cancer. In this study, we describe the incidence of and risk factors for HSIL in HIV-positive and HIV-negative homosexual and bisexual men. DESIGN: Prospective cohort study of HIV-positive and HIV-negative homosexual men. SETTING: The University of California, San Francisco. PATIENTS: 346 HIV-positive and 262 HIV-negative men enrolled at baseline, 277 HIV-positive and 221 HIV-negative homosexual men followed after baseline. STUDY DESIGN: A questionnaire was administered detailing lifestyle habits, medical history and sexual practices. Anal swabs for cytology and human papillomavirus studies were obtained, followed by biopsies of visible lesions. Human papillomavirus testing was performed using polymerase chain reaction (PCR) and 'hybrid capture'. Blood was obtained for HIV testing and measurement of CD4 levels. MAIN OUTCOME MEASURES: Incident HSIL. RESULTS: HIV-positive men were more likely to develop HSIL than HIV-negative men relative risk (RR), 3.7; 95% confidence interval (CI), 2.6-5.7. Life-table estimates of the 4-year incidence of HSIL was 49% (95% CI, 41-56) among HIV-positive men and 17% (95% CI, 12-23) among HIV-negative men. Among HIV-positive men, those with lower baseline CD4 counts (P = 0.007) and persistent infection with one or more human papillomavirus types, determined using PCR (P = 0.0001), were more likely to develop HSIL. CONCLUSIONS: HIV infection, lower CD4 levels and human papillomavirus infection were associated with high rates of incident HSIL among homosexual men. However, high rates were found at all CD4 levels among HIV-positive men and among HIV-negative men.

Epithelial-stromal interactions modulating penetration of matrigel membranes by HPV 16-immortalized keratinocytes.

The role of epithelial-stromal interactions in the progression of human papillomavirus-associated squamous intraepithelial lesions to invasive cervical cancer is poorly understood. Using the Matrigel artificial basement membrane assay as a model of keratinocyte invasion, the effects of selected growth factors on penetration of human papillomavirus 16-immortalized keratinocytes through Matrigel were studied. Also studied in this model were the effects of conditioned media from fibroblast lines derived from normal cervical tissues (normal fibroblasts) and adjacent cervical cancer biopsies (tumor-associated fibroblasts) and from primary keratinocytes. Addition of basic fibroblast growth factor, transforming growth factor-alpha, and hepatocyte growth factor/scatter factor or conditioned media from tumor-associated fibroblasts to the Matrigel resulted in near-doubling of penetration of human papillomavirus 16-immortalized keratinocytes, whereas transforming growth factor-beta, platelet derived growth factor-B, or conditioned media from primary keratinocytes decreased penetration 10-fold. Antibodies to basic fibroblast growth factor abrogated the stimulatory effects of conditioned media from tumor-associated fibroblasts on keratinocyte penetration, whereas antibodies to transforming growth factor-beta abrogated the inhibitory effects of conditioned media from normal fibroblasts on keratinocyte penetration. S1 nuclease protection and enzyme-linked immunosorbent assay showed increased expression of transforming growth factor-beta and decreased expression of basic fibroblast growth factor in normal compared with tumor-associated fibroblasts. Messenger RNA in situ hybridization of five cervical cancer biopsies demonstrated basic fibroblast growth factor expression in stromal cells surrounding nests of invading keratinocytes. Epithelial-stromal interactions mediated by growth factors such as transforming growth factor-beta and basic fibroblast growth factor modulate penetration of human papillomavirus 16-immortalized keratinocytes through Matrigel in vitro and these interactions may also be operative in vivo.

Human papillomavirus infection and anogenital neoplasia in human immunodeficiency virus-positive men and women.

Human immunodeficiency virus (HIV)-positive women have a higher prevalence of human papillomavirus (HPV) infection in the cervix and anus, as well as squamous intraepithelial lesions (SILs) at these sites, than do HIV-negative women matched for age and HIV risk factors. Similarly, HIV-positive homosexual or bisexual men have a higher prevalence of anal HPV infection and anal SIL than do HIV-negative homosexual or bisexual men. In HIV-positive individuals, the prevalence of HPV infection, the proportion infected with multiple HPV types, and the prevalence of anogenital SILs increase with decreasing CD4 count. This situation may reflect loss of systemic immune response to HPV antigens or local HPV-HIV interactions at the tissue or cellular level. Despite the high levels of anogenital SILs, to date, there has not been a significant increase in reported cases of invasive anogenital cancer in HIV-positive individuals. However, several years may be required for SIL to progress to invasive cancer, and the advent of newer therapies for HIV that are expected to prolong survival may paradoxically increase the risk of progression to cancer in individuals with SILs if these lesions do not regress spontaneously and remain untreated.

Risk factors for anal human papillomavirus infection and anal cytologic abnormalities in HIV-positive and HIV-negative homosexual men.

Men with advanced human immunodeficiency virus (HIV) disease have a high prevalence of anal human papillomavirus (HPV) infection and potentially precancerous anal disease. To characterize prevalence of and risk factors for anal HPV infection and anal cytologic abnormalities, 37 HIV-positive and 28 HIV-negative participants in the San Francisco General Hospital Cohort Study were studied. A questionnaire was administered, followed by an anal examination consisting of two consecutive anal swabs for cytology and HPV DNA hybridization, and anoscopy with biopsy of visible lesions. Ten of 28 (36%) HIV-negative men and 19 of 37 (51%) HIV-positive men had anal HPV infection (p = 0.32). Risk factors for anal HPV infection included HIV positivity with a CD4 count < 200/mm3 (p = 0.03) and a history of smoking (p = 0.03). Abnormal anal cytology was found in 2 of 26 (8%) HIV-negative men and 10 of 36 (28%) HIV-positive men with cytology adequate for interpretation (p = 0.09). Risk factors for abnormal anal cytology included HIV positivity with a CD4 count < 200/mm3 (p = 0.006) and current smoking (p = 0.03). We conclude that the risk of development of anal disease and HPV infection was highest among HIV-positive men with a CD4 count of < 200/mm3, and that smoking may play a role in the pathogenesis of anal disease.

Natural history of anal cytologic abnormalities and papillomavirus infection among homosexual men with group IV HIV disease.

Previous studies have demonstrated a high prevalence of anal cytologic abnormalities as well as anal human papillomavirus (HPV) infection among homosexual men with group IV HIV disease. However, the natural history of these changes in this population has not yet been studied. To this end, 37 homosexual men with group IV HIV disease attending an outpatient HIV clinic were followed at approximately 9-month intervals for an average of 17 months, using anal cytology, anoscopy, anal biopsy, and anal HPV DNA hybridization. During the study, the proportion of the 37 subjects with anal cytologic abnormalities increased from 27 to 65%. The proportion of subjects with any grade of anal intraepithelial neoplasia rose from 8 to 32%, with high-grade anal intraepithelial neoplasia increasing from 0 to 16%. The proportion of subjects with anal HPV infection increased from 60 to 89%, and infection with multiple HPV types was noted in at least 48%. We conclude that a large proportion of homosexual men with group IV HIV disease develop anal cytologic abnormalities, including anal intraepithelial neoplasia, over a short period of time. Together with a rapidly increasing incidence of anal cancer among single, never-married men in the San Francisco Bay area, these results suggest that these men may be at significant risk of development of anal cancer.

Urokinase plasminogen activator expression by primary and HPV 16-transformed keratinocytes.

The molecular events underlying progression of human papillomavirus (HPV) 16-associated intraepithelial neoplasia to invasive cancer have not been studied in detail. Penetration of the basement membrane is an early, but poorly understood step in this process and probably involves the action of one or more metallo- and serine proteinases. Urokinase-type plasminogen activator (uPA) is a serine proteinase that has been implicated in the pathogenesis of several epithelial tumors, but its role in HPV-associated tumors is not known. To examine uPA expression by HPV 16-transformed keratinocytes in vitro, primary foreskin keratinocyte cultures were transfected by HPV 16 DNA. The primary parental cells and the HPV 16-transformed keratinocytes were studied using substrate gel zymography, Western blot analysis and an in vitro assay measuring penetration of a Matrigel artificial basement membrane. Both uPA and its inhibitor, plasminogen activator inhibitor-1 (PAI-1), were overexpressed in the HPV 16-transformed cells relative to the parental cell line. The transformed cells, but not the parental cells, were able to degrade and penetrate the Matrigel membrane and penetration was blocked by both PAI-1 and by antibodies to uPA. Our data suggest that HPV 16-induced transformation of keratinocytes is associated with upregulation of uPA expression. In conjunction with other proteinases, uPA plays an important role in the ability of HPV 16-transformed keratinocytes to penetrate artificial basement membranes.

Anal squamous intraepithelial lesions in human immunodeficiency virus-positive men and women.

Studies from the era prior to the introduction of highly active antiretroviral therapy (HAART) have shown that the prevalence of anal human papillomavirus (HPV) infection and anal squamous intraepithelial lesions (ASIL) was very high among human immunodeficiency virus (HIV)-positive homosexual men, and to a lesser extent, among HIV-negative homosexual men. Prospective data also show that the incidence of high-grade ASIL (HSIL), the putative invasive cancer precursor lesion, was high among both HIV-positive and HIV-negative men. Studies of HIV-positive women and HIV-negative women at high risk of HIV show a high prevalence of anal HPV infection and ASIL. Early data suggest that most anal HSIL lesions do not regress after an individual begins HAART. Since progression of anal HSIL to invasive anal cancer may require several years, the improvement in survival associated with HAART may paradoxically lead to an increased risk of anal cancer. Consistent with this, the incidence of invasive anal cancer has been increasing over the last few years among HIV-positive gay men, and is now approximately twice that of HIV-negative gay men. The potential to prevent anal cancer through detection and treatment of anal HSIL suggests a need to screen high-risk individuals with anal cytology, similar to the longstanding cervical cytology screening program currently used to prevent cervical cancer. Cost-effectiveness analyses indicate that anal screening programs should be cost-effective in HIV-positive men. However, barriers to implementation of screening preclude near-term implementation of such a program. These include an inadequate number of clinicians skilled in diagnosis and treatment of HSIL and lack of effective medical alternatives to surgical excision. Efforts are underway to address these issues and to better understand the natural history of ASIL in the HAART era.