Oncogenic Oral Human Papillomavirus Clearance Patterns over 10 Years

BACKGROUND

Effective screening for oropharyngeal cancer is lacking. Four oncogenic HPV clearance definitions were explored to understand long-term natural history for persistent oncogenic oral HPV (oncHPV), the precursor of oropharyngeal cancer.

METHODS

Prospective multicenter cohort of participants living with/at-risk for HIV, with oral rinse and gargle samples collected every 6 to 12 months for up to 10 years and tested for oncHPV. HPV clearance definitions included 1 (clear1), 2 (clear2), 3 (clear3) consecutive negatives, or being negative at last two visits (clearlast).

RESULTS

Median time to clearance of oncHPV exceeded 2 years for conservative definitions (clear3: 2.38, clearlast: 2.43), but not lenient (clear1: 0.68, clear2: 1.15). By clear3, most incident infections cleared at 2, 5, 8 years (55.1%, 75.6%, 79.1%), contrary to prevalent infections (37.1%, 52.5%, 59.5%, respectively). In adjusted analysis, prevalent oncHPV, older age, male sex, and living with HIV were associated with reduced clearance. Of 1,833 subjects screened, 13.8% had prevalent oncHPV and 47.5% of those infections persisted ≥5 years, representing 6.5% of persons screened. Two men with prevalent oral HPV16 developed incident oropharyngeal cancer [IR = 1.62 per 100 person-years; 95% confidence interval (CI), 0.41-6.4]. Many with oral HPV16 persisted ≥5 years (and/or developed HPV-oropharyngeal cancer) among those with 2 (72.2%), ≥2 of first 3 (65.7%), or 3 (80.0%) consecutive positive oHPV16 tests, but not after 1 (39.4%).

CONCLUSIONS

In our 10-year study, most incident infections cleared quickly. However, half of prevalent oncHPV persisted ≥5 years, suggesting increased risk with persistent oncHPV at >2 visits.

IMPACT

We identified groups with persistent oncHPV at increased risk of oropharyngeal cancer and contextualized risk levels for those with oral HPV16 infection.

Construct validity and responsiveness of a health-related symptom index for persons either treated or monitored for anal high-grade squamous intraepithelial lesions (HSIL): AMC-A01/-A03

PURPOSE

To determine whether treatment of anal high-grade squamous intraepithelial lesions (HSIL), vs active monitoring, is effective in reducing incidence of anal cancer in persons living with HIV, the US National Cancer Institute funded the Phase III ANal Cancer/HSIL Outcomes Research (ANCHOR) clinical trial. As no established patient-reported outcomes (PRO) tool exists for persons with anal HSIL, we sought to estimate the construct validity and responsiveness of the ANCHOR Health-Related Symptom Index (A-HRSI).

METHODS

The construct validity phase enrolled ANCHOR participants who were within two weeks of randomization to complete A-HRSI and legacy PRO questionnaires at a single time point. The responsiveness phase enrolled a separate cohort of ANCHOR participants who were not yet randomized to complete A-HRSI at three time points: prior to randomization (T1), 14-70 (T2), and 71-112 (T3) days following randomization.

RESULTS

Confirmatory factor analysis techniques established a three-factor model (i.e., physical symptoms, impact on physical functioning, impact on psychological functioning), with moderate evidence of convergent validity and strong evidence of discriminant validity in the construct validity phase (n = 303). We observed a significant moderate effect for changes in A-HRSI impact on physical functioning (standardized response mean = 0.52) and psychological symptoms (standardized response mean = 0.60) from T2 (n = 86) to T3 (n = 92), providing evidence of responsiveness.

CONCLUSION

A-HRSI is a brief PRO index that captures health-related symptoms and impacts related to anal HSIL. This instrument may have broad applicability in other contexts assessing individuals with anal HSIL, which may ultimately help improve clinical care and assist providers and patients with medical decision-making.

Incidence and Clearance of Anal Human Papillomavirus Infection in 16 164 Individuals, According to Human Immunodeficiency Virus Status, Sex, and Male Sexuality: An International Pooled Analysis of 34 Longitudinal Studies

BACKGROUND

Understanding the natural history of anal high-risk human papillomavirus (hrHPV) infection is key for designing anal cancer prevention programs but has not been systematically characterized.

METHODS

We reanalyzed data from 34 studies including 16 164 individuals in 6 risk groups defined by human immunodeficiency virus (HIV) status, sex, and male sexuality: men who have sex with men (MSM) and people with HIV (MSMWH), HIV-negative MSM, women with HIV (WWH), HIV-negative women, men who have sex with women (MSW) with HIV (MSWWH), and HIV-negative MSW. We used Markov models to estimate incidence and clearance of 13 hrHPV types and their determinants.

RESULTS

Human papillomavirus (HPV) 16 had the highest incidence-clearance ratio of the hrHPV types. MSMWH had the highest hrHPV incidence (eg, 15.5% newly HPV-16 infected within 2 years), followed by HIV-negative MSM (7.5%), WWH (6.6%), HIV-negative women (2.9%), MSWWH (1.7%), and HIV-negative MSW (0.7%). Determinants of HPV-16 incidence included HIV status and number of sexual partners for MSM, women, and MSW, and anal sex behavior for MSM only. HPV-16 clearance was lower for people with HIV (PWH) and lower for prevalent than incident infection. Among MSM, increasing age was associated with lower clearance of prevalent, but not incident, HPV-16 infection.

CONCLUSIONS

This robust and unifying analysis of anal hrHPV natural history is essential to designing and predicting the impact of HPV vaccination and HPV-based screening programs on anal cancer prevention, particularly in MSM and PWH. Importantly, it demonstrates the higher carcinogenic potential of longstanding anal prevalent hrHPV infection than more recent incident infection.

Provider Preferences for Anal Cancer Prevention Screening: Results of the International Anal Neoplasia Society Survey

Objective

This study explores provider preferences regarding anal cancer screening indications, initiation age, tools, and referral threshold to high resolution anoscopy (HRA).

Methods

International Anal Neoplasia Society affiliates were invited to complete an online survey. Options for initiation age and tools were delineated by sub-groups. HRA referral thresholds separately queried recommendations by patient immune status.

Results

One hundred forty respondents participated. Although consensus was lacking with regard to specific screening initiation age, more respondents recommended younger initiation ages for men who have sex with men (MSM) living with HIV (LWH) compared with MSM not LWH (p < 0.01). “No age threshold” ranged 44-55% among sub-groups with lower genital tract disease. Cytology and digital anorectal exam (DARE) were the most frequently selected tools for all sub-groups (ranges 77-90% and 74-86%, respectively). HRA was recommended significantly more frequently for MSM LWH (58%) and patients with vulvar cancer (52%) compared to others (p < 0.01). “Any [test] abnormality” was more often selected as indication for HRA for immunocompromised (56%) and immunocompetent (46%) patients than a specific cytology test result (29%, 36% respectively).

Conclusion

Cytology and DARE were preferred screening tools; screening initiation age and HRA referral threshold showed less consensus. Evidence-based guidelines are needed and may lead to more consistent screening practices.

Abstract IA-15: Serum testosterone and estradiol modify risk of anal HPV16/18 infections but only estradiol and Estrogen Receptor 1-alpha influences risk for histological high-grade squamous intraepithelial lesions (HSIL)

Background: We reported higher serum free testosterone (FT) and anal-HPV16/18 infection prevalence in MSM. Associations between serum-FT and -estradiol, anal-HPV16/18 infections, and Estrogen Receptor 1α (ESR1) and histological HSIL (hHSIL) are unclear. Methods: Three serial cross-sectional analyses were performed using data for 489 HIV-infected/HIV-uninfected adult males enrolled in the Multicenter AIDS Cohort Study. For 340, anal cytology residuals were evaluated for 37 HPVs (PCR). For 214 men, 336 HRA/biopsies were evaluated for hHSIL; among them, &lt;3 biopsy specimens for 47% (102) were assessed for ESR1 using immunohistochemistry. Serum specimen collection preceded HPV and HRA/biopsy visits by 24(+9) months. Each specimen was tested for Sex Hormone Binding Globulin (radioimmunoassay), and total testosterone and estradiol (TE2) (Liquid chromatography/mass spectrometry); serum-FT (pg/mL) was estimated. HPVs were classified: HPV16/18+, other Group-1 and -2 high-risk HPVs+ (hrHPVs); low-risk HPVs+ (lrHPVs), and none. Biopsies were evaluated as hHSIL vs. &lt;hHSIL. Formalin-fixed paraffin-embedded anal biopsy (~4μm) were prepared and stained using a standard ESR1 immunohistochemistry protocol and were scored for immunofluorescence (0-3+) and percent affected (0-100%) by two pathologists. Multivariable-adjusted GEE logistic regression models assessed relationships between loge-transformed FT, TE2 and ESR1 (%), and HPV16/18+ and hHSIL separately. Self-reported sociodemographic/behavioral covariates were included. Results: Adjusted estimates showed higher FT increased odds of HPV16/18-infection (OR=1.87 (1.2-2.92)), but odds were inversely associated with TE2 (OR=0.68(0.49-0.94)). White race and other Group-1-hrHPVs+ increased odds for HPV16/18 infection (OR=2.61(1.16-5.87) and (OR=1.65(1.11-2.46)), but neither HIV-infection/CD4+count, receptive anal intercourse partnerships; exogenous-testosterone use, nor smoking increased HPV16/18-infection odds. Serum-TE2 and hHSIL were inversely associated (OR=0.51(0.3-0.89)) Serum-FT was not associated with odds of hHSIL (OR=1.09(0.78-1.74)), but. men testing HPV16/18+ showed higher odds of hHSIL than hrHPV-negative men (OR=4.27(1.71-10.66)). Median IHC ER1α-expression intensity was lower among hHSIL affected men: 10% (hHSIL) vs. 40% (&lt;hHSIL). The percent of immunofluorescence intensity (%) was inversely associated with odds of hHSIL (OR=0.96(0.93-0.99). Conclusions: Higher serum-FT increased odds of anal HPV16/18-infection but not hHSIL. Higher serum-TE2 was inversely associated with the odds of both HPV16/18+ and hHSIL, and ESR1 expression in tissue is lower in hHSIL- than &lt;hHSIL-affected epithelium. More research evaluating sex hormones and ERα expression in stroma and epithelial cells of HPV-associated HSIL/&lt;HSIL-affected tissue is needed.

Citation Format: Dorothy J. Wiley. Serum testosterone and estradiol modify risk of anal HPV16/18 infections but only estradiol and Estrogen Receptor 1-alpha influences risk for histological high-grade squamous intraepithelial lesions (HSIL) [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr IA-15.

Prevalence of and Risk Factors for Anal High-grade Squamous Intraepithelial Lesions in Women Living with Human Immunodeficiency Virus

BACKGROUND

Women living with human immunodeficiency virus (WLHIV) have disproportionately high rates of squamous cell carcinoma of the anus compared with the general population of women. Anal high-grade squamous intraepithelial lesions (HSILs) precede anal cancer, and accurate studies of HSIL prevalence among WLHIV in the United States are lacking.

METHODS

The AIDS Malignancy Consortium 084 study was a multicenter national trial to evaluate the prevalence of and risk factors for anal HSIL in a US cohort. Eligible participants were WLHIV aged ≥18 years with no history of anal HSIL. Study participants had an examination including collection of cervical/vaginal and anal specimens, followed by high-resolution anoscopy with biopsy.

RESULTS

We enrolled 256 women with evaluable anal pathology. The mean age was 49.4 years, 64% women were non-Hispanic black, 67% were former or current smokers, and 56% reported ever having anal sex with a man. The median CD4 T-cell count was 664 cells/μL. The prevalence of anal histologic HSIL (hHSIL) was 27% (95% confidence interval [CI], 22%-33%). There was a strong concordance (240/254) between local and consensus pathologists for hHSIL vs less than hHSIL (κ = 0.86 [95% CI, .79-.93]). Current CD4 count of ≤200 cells/μL was the strongest predictor of consensus anal hHSIL diagnosis (adjusted odds ratio [aOR], 10.34 [95% CI, 3.47-30.87]). History of anoreceptive intercourse was also associated with hHSIL (aOR, 2.44 [95% CI, 1.22-4.76]).

CONCLUSIONS

The prevalence of anal hHSIL in WLHIV in the United States was 27% in this study where all participants received high-resolution anoscopy and biopsy.

Long-term Persistence of Oral HPV Over 7 Years of Follow-up

Background

Human papillomavirus–related oropharyngeal cancer (HPV-OPC) incidence is increasing, but the natural history of the precursor—oral HPV—has not been well described.

Methods

This observational cohort study of people living with HIV and at-risk HIV uninfected people evaluated participants semiannually using 30-second oral rinse and gargle specimens over 7 years. Initially, 447 participants were followed for 4 years as part of the Persistent Oral Papillomavirus Study, and a subset of 128 who showed persistent infections at the last Persistent Oral Papillomavirus Study visit had an additional visit, as part of the Men and Women Understanding Throat HPV Study, on average 2.5 years later. Extracted DNA from oral rinse and gargle specimens was amplified using polymerase chain reaction and type specification of 13 oncogenic HPV types. Risk factors for oncogenic oral HPV clearance were evaluated using Cox models.

Results

The majority of oncogenic oral HPV infections cleared quickly, with a median time to clearance of 1.4 years (interquartile range = 0.5-3.9 years). After 7 years of follow-up, 97% of incident and 71% of prevalent infections had cleared. Lower HPV-16 viral load was statistically significantly associated with clearance (per 10-fold decrease in copy number: adjusted hazard ratio [aHR] = 2.51, 95% confidence interval [CI] = 1.20 to 5.26; P = .01). Adjusted analyses showed that oncogenic oral HPV clearance was lower among prevalent than incident-detected infections (aHR = 0.44, 95% CI = 0.35 to 0.55), among men than women (aHR = 0.74, 95% CI = 0.60 to 0.91), for older participants (aHR per 10 years increasing age = 0.81, 95% CI = 0.74 to 0.89), and among people living with HIV (aHR = 0.76, 95% CI = 0.60 to 0.95). One participant who had oral HPV-16 consistently detected at 10 study visits over 4.5 years was subsequently diagnosed with HPV-OPC.

Conclusions

This prospective study of oncogenic oral HPV infection is the longest and largest quantification of oral HPV-16 infections to date.

Evaluating the Utility and Prevalence of HPV Biomarkers in Oral Rinses and Serology for HPV-related Oropharyngeal Cancer

Performance of commercially available human papillomavirus (HPV) assays (approved for cervical HPV detection) is unknown for detecting HPV-related oropharyngeal cancer (HPV-OPC). Assays for detection of HPV DNA [ELISA (DEIA) and Cobas], and RNA (Aptima) in oral rinse samples, and serum HPV oncogene antibodies were evaluated. Sensitivity and specificity of each test was explored among HPV-OPC cases and controls. Biomarker prevalence was evaluated among 294 "at-risk" people (screening) and 133 "high-risk" people [known to previously have oral oncogenic HPV (oncHPV) DNA and/or HPV16 E6/E7 antibodies detected]. HPV16 E6 antibodies had the best overall test performance with sensitivity of 88%, compared with oral HPV16 DNA sensitivity of 51% by DEIA and 43% by Cobas (each P < 0.001). Specificity was comparable in each of these tests (≥98%). When positivity for any oncHPV type was compared with HPV16 for the same test, sensitivity was comparable (60% vs. 51%, 40% vs. 43%, and 92% vs. 88% for DEIA, Cobas, and E6 antibodies, respectively), but specificity was reduced (93%-97%). Aptima had poor sensitivity (23%). Sensitivity decreased when cotesting HPV16 oral rinse DNA and E6 antibodies (37%-48%), or multiple E antibodies (69%-72%). HPV16 DNA were detected in ∼2% of the at-risk by either DEIA or Cobas and up to 15% of the high-risk population. HPV16 E6 seroprevalence was 2.3% and 2.4% in the at-risk and high-risk populations, respectively. Oral rinse HPV testing had moderate-to-poor sensitivity for HPV-OPC, suggesting many true positives would be missed in a potential screening scenario. HPV16 E6 serum antibody was the most promising biomarker evaluated.

Comparison of nylon-flocked swab and Dacron swab cytology for anal HSIL detection in transgender women and gay, bisexual, and other men who have sex with men

BACKGROUND

An anal histological high-grade squamous intraepithelial lesion (hHSIL) is an anal cancer precursor. Experts recommend Dacron swab anal cytology as a primary screen for anal hHSILs, especially among human immunodeficiency virus-infected and -uninfected men who have sex with men (MSM). Studies have shown that Dacron cytology inaccurately predicts anal hHSILs and results in unnecessary diagnostic procedures. Nylon-flocked (NF) swabs have been shown to trap pathogens and cells well. Thus, this study compared test characteristics of anal cytology using NF and Dacron swab collection protocols to predict anal hHSILs.

METHODS

A single-visit, randomized clinical trial compared NF and Dacron swab anal cytology specimens to predict high-resolution anoscopy and biopsy-diagnosed anal hHSILs. Data for 326 gay men, bisexual men, other MSM, and male-to-female transgender women contributed descriptive and tabular statistics with which unadjusted and fully adjusted logistic regression models were constructed. The models estimated the odds of hHSILs, test accuracy (area under the curve [AUC]) and sensitivity, and specificity as well as the positive and negative predictive values of abnormal NF and Dacron cytology for predicting hHSILs.

RESULTS

In the fully adjusted model, the sensitivities for NF and Dacron cytology were nearly equal (48% vs 47%), but the specificity was higher with NF cytology (76% vs 69%). Comparisons of the areas under receiver operating characteristic curves showed that NF cytology alone predicted hHSILs better than the covariate model (AUC, 0.69 vs 0.63; P = .02), but NF and Dacron cytology comparisons showed no statistically significant differences (AUC, 0.69 vs 0.67; P = .3).

CONCLUSIONS

NF cytology and Dacron cytology provide modest sensitivity, but NF cytology has higher specificity and accuracy, and this is important for lowering the costs of population-based screening.

Patterns of repeated anal cytology results among HIV-positive and HIV-negative men who have sex with men

Background

Men who have sex with men (MSM) are at increased risk for anal cancer. In cervical cancer screening, patterns of repeated cytology results are used to identify low- and high-risk women, but little is known about these patterns for anal cytology among MSM.

Methods

We analyzed Multicenter AIDS Cohort Study (MACS) data for MSM who were offered anal cytology testing annually (HIV-positive) or every 2 years (HIV-negative) for 4 years.

Results

Following an initial negative (normal) cytology, the frequency of a second negative cytology was lower among HIV-positive MSM with CD4 ≥ 500 (74%) or CD4 < 500 (68%) than HIV-negative MSM (83%) (p < 0.001). After an initial abnormal cytology, the frequency of a second abnormal cytology was highest among HIV-positive MSM with CD4 < 500 (70%) compared to CD4 ≥ 500 (53%) or HIV-negative MSM (46%) (p = 0.003). Among HIV-positive MSM with at least three results, 37% had 3 consecutive negative results; 3 consecutive abnormal results were more frequent among CD4 < 500 (22%) than CD4 ≥ 500 (10%) (p = 0.008).

Conclusions

More than one-third of HIV-positive MSM have consistently negative anal cytology over three years. Following abnormal anal cytology, a repeated cytology is commonly negative in HIV-negative or immunocompetent HIV-positive men, while persistent cytological abnormality is more likely among HIV-positive men with CD4 < 500.

Final efficacy, immunogenicity, and safety analyses of a nine-valent human papillomavirus vaccine in women aged 16-26 years: a randomised, double-blind trial

BACKGROUND

Primary analyses of a study in young women aged 16-26 years showed efficacy of the nine-valent human papillomavirus (9vHPV; HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58) vaccine against infections and disease related to HPV 31, 33, 45, 52, and 58, and non-inferior HPV 6, 11, 16, and 18 antibody responses when compared with quadrivalent HPV (qHPV; HPV 6, 11, 16, and 18) vaccine. We aimed to report efficacy of the 9vHPV vaccine for up to 6 years following first administration and antibody responses over 5 years.

METHODS

We undertook this randomised, double-blind, efficacy, immunogenicity, and safety study of the 9vHPV vaccine study at 105 study sites in 18 countries. Women aged 16-26 years old who were healthy, with no history of abnormal cervical cytology, no previous abnormal cervical biopsy results, and no more than four lifetime sexual partners were randomly assigned (1:1) by central randomisation and block sizes of 2 and 2 to receive three intramuscular injections over 6 months of 9vHPV or qHPV (control) vaccine. All participants, study investigators, and study site personnel, laboratory staff, members of the sponsor's study team, and members of the adjudication pathology panel were masked to vaccination groups. The primary outcomes were incidence of high-grade cervical disease (cervical intraepithelial neoplasia grade 2 or 3, adenocarcinoma in situ, invasive cervical carcinoma), vulvar disease (vulvar intraepithelial neoplasia grade 2/3, vulvar cancer), and vaginal disease (vaginal intraepithelial neoplasia grade 2/3, vaginal cancer) related to HPV 31, 33, 45, 52, and 58 and non-inferiority (excluding a decrease of 1·5 times) of anti-HPV 6, 11, 16, and 18 geometric mean titres (GMT). Tissue samples were adjudicated for histopathology diagnosis and tested for HPV DNA. Serum antibody responses were assessed by competitive Luminex immunoassay. The primary evaluation of efficacy was a superiority analysis in the per-protocol efficacy population, supportive efficacy was analysed in the modified intention-to-treat population, and the primary evaluation of immunogenicity was a non-inferiority analysis. The trial is registered with ClinicalTrials.gov, number NCT00543543.

FINDINGS

Between Sept 26, 2007, and Dec 18, 2009, we recruited and randomly assigned 14 215 participants to receive 9vHPV (n=7106) or qHPV (n=7109) vaccine. In the per-protocol population, the incidence of high-grade cervical, vulvar and vaginal disease related to HPV 31, 33, 45, 52, and 58 was 0·5 cases per 10 000 person-years in the 9vHPV and 19·0 cases per 10 000 person-years in the qHPV groups, representing 97·4% efficacy (95% CI 85·0-99·9). HPV 6, 11, 16, and 18 GMTs were non-inferior in the 9vHPV versus qHPV group from month 1 to 3 years after vaccination. No clinically meaningful differences in serious adverse events were noted between the study groups. 11 participants died during the study follow-up period (six in the 9vHPV vaccine group and five in the qHPV vaccine group); none of the deaths were considered vaccine-related.

INTERPRETATION

The 9vHPV vaccine prevents infection, cytological abnormalities, high-grade lesions, and cervical procedures related to HPV 31, 33, 45, 52, and 58. Both the 9vHPV vaccine and qHPV vaccine had a similar immunogenicity profile with respect to HPV 6, 11, 16, and 18. Vaccine efficacy was sustained for up to 6 years. The 9vHPV vaccine could potentially provide broader coverage and prevent 90% of cervical cancer cases worldwide.

FUNDING

Merck & Co, Inc.

The association of medication use with clearance or persistence of oral HPV infection

PURPOSE

Persistent oral human papillomavirus (HPV) infection increases risk for oropharyngeal carcinoma, and people living with HIV have higher rates of oral HPV infection and related cancers. Some prescription medications have immunomodulatory effects, but the impact of medication use on oral HPV natural history is unknown.

METHODS

Scope^® oral rinse-and-gargle samples were collected semi-annually from 1,666 participants and tested for 37 types of oral HPV DNA using PCR; 594 HPV-infected participants with 1,358 type-specific oral HPV infections were identified. Data were collected on recent (past 6 months) use of medications. The relationship between medication use and oral HPV clearance was evaluated using Wei-Lin-Weissfeld regression, adjusting for biologic sex, prevalent versus incident infection, age, HIV status and CD4+ T cell count.

RESULTS

Out of 11 medications examined, oral HPV clearance was significantly reduced in participants reporting recent use of antipsychotics (HR 0.75, 95% CI 0.57-0.99), anxiolytics/sedatives (HR 0.78, 95% CI 0.63-0.96) and antidepressants (HR 0.82, 95% CI 0.67-0.999). Among antipsychotics users, effect modification by HIV status was observed, with reduced clearance in HIV-infected (HR 0.67, 95% CI 0.49-0.91), but not HIV-uninfected participants (p-interaction = 0.009). After adjusted analysis, antipsychotic use remained significantly associated with reduced oral HPV clearance overall (aHR 0.75, 95% CI 0.57-0.99), and when restricted to only HIV-infected participants (aHR 0.66, 95% CI 0.48-0.90). After adjustment, anxiolytic/sedative use and antidepressant use were no longer significantly associated with reduced oral HPV clearance.

CONCLUSIONS

Some medications were associated with decreased oral HPV clearance, most notably antipsychotic medications. These medications are prescribed for conditions that may have immunomodulating effects, so characteristics of underlying illness may have partially contributed to reduced oral HPV clearance.

Association of serum cytokines with oral HPV clearance

BACKGROUND

Initial studies suggest higher serum levels of some pro-inflammatory cytokines may be associated with decreased cervical human papillomavirus (HPV) clearance. However, the relationship of cytokines with oral HPV clearance has not been explored.

METHODS

From 2010 to 2014, oral rinse and serum samples were collected semi-annually from 1601 adults. Oral rinse samples were tested for HPV DNA using PCR. Based on oral HPV results, 931 serum samples were selected for cytokine evaluation to include a roughly equal number of prevalent (n=307), incident (n=313), and no oral HPV infections (n=311). Electrochemiluminescence multiplex assays were used to determine the concentrations of IL-6, IL-8, TNF-α, IFN-γ, IL-1β, IL-2, IL-4, IL-10, IL-12 and IL-13. The relationship between serum cytokine concentrations (categorized into quartiles) and oral HPV clearance was evaluated with Wei-Lin-Weissfeld regression models, adjusting for HPV infection type (prevalent vs. incident), age, HIV status, and CD4 T cell count.

RESULTS

Higher TNF-α concentration was associated with decreased clearance in men (highest vs. lowest quartile, adjusted hazard ratio [aHR]=0.52, 95% CI=0.34-0.79) and women (aHR=0.76, 95% confidence interval [CI]=0.55-1.04), with stronger associations in men than women (p-interaction=0.049). Higher IL-2 concentration was associated with reduced clearance in men (aHR=0.69, 95% CI=0.50-0.95), but not women (p-interaction=0.058). Results were similar within CD4 T cell strata (CD4⩾500 or CD4<500 cells/μl) among HIV-infected participants. No other cytokines were associated with clearance.

CONCLUSION

High serum TNF-α is associated with reduced clearance of oral HPV infection.

Physical Activity and Its Association with Insulin Resistance in Multicenter AIDS Cohort Study Men

The association between physical activity (PA), degree of insulin resistance (IR), and HIV infection is unclear. We hypothesized that PA might differentially affect the degree of IR through the direct and indirect influences of HIV, antiretroviral medications, and sociodemographic characteristics. The International Physical Activity Questionnaire (IPAQ) was administered to Multicenter AIDS Cohort Study (MACS) participants from 4/2010 to 3/2011 to generate metabolic equivalents (METs) total score and PA category. We determined the concurrent homeostatic model assessment IR (mmol/liter) (HOMA-IR) value from fasting glucose and insulin. We examined the HIV-PA relationship using quantile regression and the HIV-PA-HOMA-IR value relationship using linear regression. Among the 1,281 men, the proportions of men in the low (25% in HIV(+) vs. 23% in HIV(-)), moderate (26% vs. 27%), and high (49% vs. 49%) PA categories were similar by HIV status. The HOMA-IR value was higher among the HIV(+) men (p<0.001), and both HIV infection and low PA were associated with a higher degree of IR (p<0.0001 and p=0.0007). However, the PA-HOMA-IR value interaction was not different by HIV status. The HOMA-IR value was higher among HIV(+) men although the PA was similar. It is unknown if more exercise will overcome the metabolic derangements associated with HIV and its treatment.

Screening for Anal Cancer in Women

OBJECTIVE

The incidence of anal cancer is higher in women than men in the general population and has been increasing for several decades. Similar to cervical cancer, most anal cancers are associated with human papillomavirus (HPV), and it is believed that anal cancers are preceded by anal high-grade squamous intraepithelial lesions (HSIL). Our goals were to summarize the literature on anal cancer, HSIL, and HPV infection in women and to provide screening recommendations in women.

METHODS

A group of experts convened by the American Society for Colposcopy and Cervical Pathology and the International Anal Neoplasia Society reviewed the literature on anal HPV infection, anal SIL, and anal cancer in women.

RESULTS

Anal HPV infection is common in women but is relatively transient in most. The risk of anal HSIL and cancer varies considerably by risk group, with human immunodeficiency virus-infected women and those with a history of lower genital tract neoplasia at highest risk compared with the general population.

CONCLUSIONS

While there are no data yet to demonstrate that identification and treatment of anal HSIL leads to reduced risk of anal cancer, women in groups at the highest risk should be queried for anal cancer symptoms and required to have digital anorectal examinations to detect anal cancers. Human immunodeficiency virus-infected women and women with lower genital tract neoplasia may be considered for screening with anal cytology with triage to treatment if HSIL is diagnosed. Healthy women with no known risk factors or anal cancer symptoms do not need to be routinely screened for anal cancer or anal HSIL.

High Oral Human Papillomavirus Type 16 Load Predicts Long-term Persistence in Individuals With or at Risk for HIV Infection

The association between oral human papillomavirus 16 (HPV16) DNA load and infection clearance was evaluated among 88 individuals with oral HPV16 infection who were identified within a prospective cohort of 1470 HIV-infected and uninfected individuals. Oral rinse specimens were collected semiannually for up to 5 years. The oral HPV16 load at the time of the first positive test result was significantly associated with the time to clearance of infection (continuous P trends <.01). Notably, clearance rates by 24 months were 41% and 94% in the highest and lowest HPV16 load tertiles (P = .03), respectively. High oral HPV16 load warrants consideration as a biomarker for infection persistence, the presumed precursor of HPV16-associated oropharyngeal cancer.

Association between free testosterone levels and anal human papillomavirus types 16/18 infections in a cohort of men who have sex with men

BACKGROUND

Human papillomavirus (HPV) types 16 and 18 cause invasive cervical cancer and most invasive anal cancers (IACs). Overall, IAC rates are highest among men who have sex with men (MSM), especially MSM with HIV infection. Testosterone is prescribed for men showing hypogonadism and HIV-related wasting. While there are direct and indirect physiological effects of testosterone in males, its role in anal HPV16/18 infections in men is unknown.

METHODS

Free testosterone (FT) was measured in serum from 340 Multicenter AIDS Cohort Study (MACS) participants who were tested for anal HPV16/18-DNA approximately 36 months later. The effect of log10-transformed current FT level on anal HPV16/18 prevalence was modeled using Poisson regression with robust error variance. Multivariate models controlled for other HPV types, cumulative years of exogenous testosterone use, race, age, lifetime number of receptive anal intercourse partnerships, body mass index, tobacco smoking, HIV-infection and CD4+ T-cell counts among HIV-infected, and blood draw timing.

RESULTS

Participants were, on average, 60 (+5.4) years of age, White (86%), and HIV-uninfected (56%); Twenty-four percent tested positive for anal HPV16 and/or 18-DNA (HPV16 prevalence=17.1%, HPV18=9.1%). In adjusted analysis, each half-log10 increase of FT was associated with a 1.9-fold (95% Confidence Interval: 1.11, 3.24) higher HPV16/18 prevalence. Additionally, other Group 1 high-risk HPVs were associated with a 1.56-fold (1.03, 2.37) higher HPV16/18 prevalence. Traditional risk factors for HPV16/18 infection (age, tobacco smoking; lifetime number of sexual partners, including the number of receptive anal intercourse partnerships within 24 months preceding HPV testing) were poorly correlated with one another and not statistically significantly associated with higher prevalence of HPV16/18 infection in unadjusted and adjusted analyses.

CONCLUSIONS

Higher free testosterone was associated with increased HPV16/18 prevalence measured approximately three years later, independent of sexual behavior and other potential confounders. The mechanisms underlying this association remain unclear and warrant further study.

Risk factors for acquisition and clearance of oral human papillomavirus infection among HIV-infected and HIV-uninfected adults

Human papillomavirus (HPV) causes the majority of oropharyngeal cancers in the United States, yet the risk factors for and natural history of oral HPV infection are largely unknown. In 2010-2011, a US-based longitudinal cohort study of 761 human immunodeficiency virus (HIV)-infected and 469 at-risk HIV-uninfected participants from the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study was initiated. Semiannually collected oral rinses were evaluated for 37 HPV genotypes using the Roche LINEAR ARRAY HPV Genotyping Test (Roche Molecular Systems, Pleasanton, California), and factors associated with oral HPV incidence and clearance were explored using adjusted Wei-Lin-Weissfeld modeling. Through 2013, the 2-year cumulative incidence of any type of oral HPV infection was 34% in HIV-infected persons and 19% in HIV-uninfected persons. However, many of these infections cleared. Seven percent of incident infections and 35% of prevalent infections persisted for at least 2 years. After adjustment for other risk factors, HIV infection (adjusted hazard ratio = 2.3, 95% confidence interval: 1.7, 3.2), reduced current CD4 cell count, and increased numbers of oral sex and "rimming" partners increased the risk of incident oral HPV infection, whereas male sex, older age, and current smoking increased the risk of oral HPV persistence (each P < 0.05). This helps explain the consistent associations observed between these factors and prevalent oral HPV infection in previous cross-sectional studies.

Validation of an HPV16-mediated carcinogenesis mouse model

BACKGROUND/AIM

Human papillomavirus Type 16 (HPV16) infection is a necessary but alone insufficient cause of invasive cervical cancer (ICC) and likely causes other genital cancers. Individual genetic variability influences the natural history of the neoplasm. Developing a variety of animal models to investigate HPV16-mediated carcinogenesis is important to Phase 1 trials for human cancer treatments.

MATERIALS AND METHODS

C57BL/6 mice expressing the HPV16-E7 transgene were treated with 100 nmoles of 7,12-dimethylbenz(a)anthracene (DMBA) on dorsal-thoracolumbar skin for ≤20 weeks.

RESULTS

Transgenic-HPV16E7 mice showed more tumors (14.11±1.49 vs. 7.2±0.73) that more quickly reached maximal size (17.53±0.53 vs. 28.75±0.67 weeks) than syngeneic controls.

CONCLUSION

DMBA topically-treated C57BL/6-HPV16E7 mice developed chronic inflammation as well as benign and malignant lesions, many of which ulcerated. Histology showed that the HPV16-E7 transgene more than doubled the effect of complete carcinogenesis against a C57BL/6 background alone, strongly influencing the number, size, and time-to-maximal tumor burden for DMBA-exposed transgenic-C57BL/6 mice.

Factors affecting the prevalence of strongly and weakly carcinogenic and lower-risk human papillomaviruses in anal specimens in a cohort of men who have sex with men (MSM)

Background

MSM are at higher risk for invasive anal cancer. Twelve human papillomaviruses (HPVs) cause cervical cancer in women (Group 1 high-risk HPVs (hrHPVs)) and 13 HPVs are probable/possible causes (Group 2 hrHPVs) of cervical malignancy. HPVs rarely associated with malignancy are classified as lower-risk HPVs (lrHPVs).

Materials and Methods

Dacron-swab anal-cytology specimens were collected from and data complete for 97% (1262/1296) of Multicenter AIDS Cohort Study (MACS) men tested for HPVs using the Linear Array assay. Multivariate Poisson regression analyses estimated adjusted prevalence ratios for Group 1/2 hrHPVs and lrHPVs, controlling for the effects of age, race, ethnicity, sexual partnerships, smoking; HIV-infection characteristics, treatment, and immune status among HIV-infected men.

Results

HIV-infected men showed 35–90% higher prevalence of Group 1/2 hrHPVs and lrHPVs than HIV-uninfected men, and higher prevalence of multi-Type, and multiple risk-group infections. CD4+ T-cell count was inversely associated with HPV Group 2 prevalence (p<0.0001). The number of receptive anal intercourse (RAI) partners reported in the 24 months preceding HPV testing predicted higher prevalence of Group 1/2 hrHPVs. Men reporting ≥30 lifetime male sex partners before their first MACS visit and men reporting ≥1 RAI partners during the 24 months before HPV testing showed 17–24% and 13–17% higher prevalence of lrHPVs (p-values ≤0.05). Men reporting smoking between MACS visit 1 and 24 months before HPV testing showed 1.2-fold higher prevalence of Group 2 hrHPVs (p = 0.03). Both complete adherence to CART (p = 0.02) and HIV load <50 copies/mL (p = 0.04) were protective for Group 1 hrHPVs among HIV-infected men.

Conclusions

HIV-infected men more often show multi-type and multi-group HPV infections HIV-uninfected men. Long-term mutual monogamy and smoking cessation, generally, and CART-adherence that promotes (HIV) viremia control and prevents immunosuppression, specifically among HIV-infected MSM, are important prevention strategies for HPV infections that are relevant to anal cancer.

Decision-making about cervical cancer screening methods by homeless women

To evaluate the perspectives and preferences of homeless women for traditional provider- and a novel low cost self-collected cytology screening technique, 17 interviews were conducted with women who participated in both phases of a comparative trial. Subjects were recruited from a comprehensive homeless service center and a residential program serving homeless women. Constructivist grounded theory guided data collection and analysis. Results showed self-collection was favored over provider-collected cytology, but that the women perceived that test accuracy trumped comfort. Although many women expressed inaccurate perceptions and beliefs about cervical cancer and screening, the women participated in and valued screening. Misconceptions about cervical malignancy and prevention strategies contributed to their complex appraisal of the two screening methods. Homeless women may partner with providers to develop and test effective interventions with high promise for improving their health and these insights may aid in developing effective interventions for diverse underserved communities.

17. Serum free testosterone levels associated with anal human papillomavirus types 16/18 in a cohort of men who have sex with men

Background Human papillomavirus (HPV) types 16/18 are significant causes of female cervical cancers and likely cause most anal cancers. Oestrogen influences HPV-related cervical malignancies; however, the role of testosterone in anal HPV16/18 infections is unknown. Methods: 340 men who have sex with men (MSM) enrolled in the Multicenter AIDS Cohort Study were tested for serum free testosterone (SFT) and, ~24 months later, anal HPV16/18-DNA. Poisson regression with robust error variance analyses estimated prevalence ratios for HPV16/18 infections with the following exposures: log10-transformed SFT, exogenous and supraphysiological testosterone measures, race, age, self-reported number of anal receptive intercourse partnerships ≤24 months before testing, enrolment period, body mass index, hepatitis C infection, tobacco and alcohol, HIV infection, and CD4+ T-cell counts among the HIV-infected. Stratified-tabular analyses also evaluated blood draw timing (AM/PM), study site, and time on study. Results: 89% (304/340) of men provided complete data for all covariates. On average, men were White (263/304), 60 years old (s.d. 5.3; median 60.1 years) with 76.2 ng dL–1 (s.d. 57.1; median 69.0 ng dL–1) SFT, and 43% (132/304) were HIV infected; 25% (75/304) tested HPV16/18-DNA positive. The fully adjusted model suggests each half-log10 increase of SFT is associated with a 1.69-fold (95% confidence interval (CI): 1.08, 2.64) higher HPV16/18 prevalence. Compared with HIV-uninfected men, HPV16/18 prevalence was 1.81-fold higher (95% CI: 1.08, 3.03) for HIV-infected men with ≤500 CD4+ T-cells mm–3. No other covariates were significantly associated with HPV16/18 prevalence. Conclusions: Higher free testosterone is associated with increased HPV16/18 prevalence in MSM, independent of sexual behaviour and other potential confounders. The mechanisms underlying this association remain unclear and warrant further study.

Abstract 551: Human papillomavirus (HPV) infection characteristics in a cohort of men who have sex with men (MSM) during long-term follow-up

Purpose: To describe sociodemographic, HIV and HPV infection characteristics in MACS men. Background: HPV-associated invasive anal cancer (IAC) is a health crisis for gay, bisexual, transgender and other MSM. MSM show 20-40 fold higher risk for IAC, especially within the context of HIV and since the introduction of combined antiretroviral therapy (CART) (1-4). Experts classify high-risk HPVs as having sufficient (Group 1) or limited (Group 2) evidence of causality for cervical cancer. The prevalence of these HPVs in MSM may inform risk for cancer. Methods: For 1262 MACS men evaluated at visits 56-58, Dacron swab specimens were tested for HPV using the Linear Array assay (Roche Diagnostic Laboratories, Pleasanton, CA). HPVs were classified as high-risk Groups 1 (HPV16/18/31/33/35/39/45/51/52/56/58/59) and 2 (HPV26/30/34/53/66/67/68/69/70/73/82), and low-risk HPVs (HPV6/11/40/42/54/56/61/62/64/70/71/72/82/83/84/IS39/CP6108). Descriptive and tabular analyses were used to explore the data. Poisson regression with robust error variance analyses were used to estimate prevalence ratios (PR, (95% confidence intervals)) comparing HPV groupings in both univariate and multivariate models using the SAS 9.2 GENMOD procedure (SAS Institute, Cary, North Carolina, USA). Final models included age and race, period-specific self-reported number of sexual partnerships, HIV-infection status, and CD4+ count (cell/mm3) among HIV-infected participants. Results: Participants are best described as older (µ=55 (9.4), M=55.6), and although Whites comprised &gt;50% of both groups, HIV-infected men were &gt;2 times as likely as uninfected men to report being Black, 25% vs. 10%. On average, the prevalence of all HPVs was 1.35-1.91 fold higher among HIV-infected than -uninfected men. Trend analyses showed CD4+ cell count was inversely associated with HPV Group 2 prevalence alone (p&lt;0.0001). Only the number of receptive anal sex partners reported in the 24 months preceding the HPV test visit consistently predicted higher prevalence of Group 1 and 2 HPVs. However, for low-risk HPVs, the lifetime number of male sex partners reported at MACS visit 1, partners reported between visit 1 and the visit 24 months before HPV testing, and those recorded during the last 24 months were all significantly and positively associated with higher prevalence of low-risk HPVs (p=&lt;0.05), e.g., 30+ vs. &lt;30 lifetime male partners at visit 1, PR=1.20 (1.06, 1.37); receptive anal intercourse partners during the last 24 mo prior to HPV testing, 1-3 and &gt;4 vs. 0: PR=1.13 (1.01, 1.26) and 1.16 (1.05, 1.30), respectively. Conclusions: HIV-infected MSM demonstrated a higher prevalence of all HPV groups evaluated and while number of sex partners were important for predicting the prevalence of low-risk HPVs, only the most recent receptive anal intercourse partnerships predicted prevalence of Group 1 and 2 HPVs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 551. doi:1538-7445.AM2012-551

Risk factors for oral HPV infection among a high prevalence population of HIV-positive and at-risk HIV-negative adults

INTRODUCTION

Human papillomavirus (HPV) is an important risk factor for oropharyngeal cancer. Individuals with human immunodeficiency virus (HIV) have higher oral HPV prevalence but the risk factors for oral HPV infection are not well understood for either HIV-positive or HIV-negative individuals.

METHODS

This study was nested within the Multicenter AIDS Cohort Study (MACS; men) and Women Interagency HIV Study (WIHS; women) cohorts. Exfoliated oral epithelial cells were collected from 379 HIV-positive and 266 at-risk HIV-negative individuals using a rinse and gargle with Scope mouthwash. Samples were tested for 36 types of HPV DNA using PGMY09/11 consensus primers and reverse line blot hybridization. Risk factors for oral HPV infection were explored using logistic regression with generalized estimating equations in this cross-sectional analysis.

RESULTS

Prevalent oral HPV infection was common (34%), including HPV16 infection in 5.7% of participants. HIV-positive individuals had increased odds of prevalent oral HPV infection compared with HIV-negative individuals [adjusted OR = 2.1; 95% confidence interval (CI), 1.6-2.8]. Risk factors for prevalent oral HPV differed in HIV-positive and HIV-negative participants. Among HIV-negative individuals, higher number of recent oral sex or rimming partners were strong risk factors for prevalent oral HPV infection (each P(trend) < 0.01). In contrast, among HIV-positive individuals, lower CD4 T-cell count (P(trend) < 0.001) and higher number of lifetime sexual partners (P(trend) = 0.03) were strong risk factors.

CONCLUSIONS

Oral HPV prevalence was elevated in HIV-positive individuals after controlling for differences in cigarette smoking and sexual behavior, supporting the possibility that HIV may affect the natural history of oral HPV.

IMPACT

Immunosuppression may contribute to increased persistence or progression of oral HPV infection.

Abstract C31: DMBA-induced skin tumors in HPV16 E7 transgenic mice are affected by bovine α-lactalbumin made lethal to tumor cells (BAMLET)

Background and Purpose: Human papillomavirus Type 16 (HPV16) infection is necessary but not alone a sufficient causal risk factor for cervical and other anogenital cancers and nearly 25% of head and neck malignancies (1, 2). HPV16 E7 is one of the important oncoproteins that promotes carcinogenesis. Most treatments for cervical precancers are ablative and few therapeutic drugs are available. Human α-Lactalbumin Made Lethal to Tumor Cells (HAMLET), a complex of Human α-Lactalbumin and oleic acid shows promise for treating skin papillomas by differentially inducing apoptosis in transformed cells without adverse effects on normal cells. Bovine α-Lactalbumin Made Lethal to Tumor Cells (BAMLET) has been shown to be biologically equivalent to HAMLET (3) and in vitro studies suggest BAMLET and HAMLET show similar cytotoxic effects in tumor cell lines (4). Further, in vitro studies suggest both a dose- and time-dependent response to BAMLET treatment (3–6). To determine the effect of BAMLET on tumor number, size and histological characteristics in vivo, we compared two groups of BAMLET-treated with normal saline (NS)-treated HPV16 E7 transgenic C57/BL6 mice (TG) and syngeneic mice receiving chemical carcinogen DMBA topically to induce skin tumor.

Methods: For 56 TG and syngeneic mice, in six treatment groups, 100nmol/200μl DMBA was applied topically on the dorsal thoracic flank for up to 20 weeks. BAMLET, 0.7 mM, was applied daily for 7d before and either 11d (18d BAMLET) or up to 23 weeks (24w BAMLET) following DMBA initiation. As a comparison, NS was similarly applied to 10 TG and syngeneic mice for a total of 24 weeks. A series of bivariate zero-inflated repeated-measures Poisson (ZIP) models predicted the number of papillomas based on TG/syngeneic groupings, and treatment group. The fully adjusted model evaluated the effect of the TG, treatment group and duration, and time on study for predicting the number of tumors. Least-squares linear regression (LSLR) was used to estimate the effect of treatment on average tumor size at censoring or death, controlling for the effect of gender, among the transgenic mice.

Results: On average, papillomas developed after 9 weeks of DMBA treatment. Analyses showed TG-mice developed more tumors than did syngeneic mice (p&lt;0.0001), controlling for the effect of time on study (p&lt;0.0001). In the fully adjusted analyses, the number of tumors was most affected by the TG (p&lt;0.0001) and time on study (p&lt;0.0001), but treatment showed no effect: 18d (p=0.9) and 24w (p=0.8) vs. normal saline (NS). Among transgenic mice, time on study was shorter than for syngeneic comparators and was a proxy indicator across treatment groups, confounding the ZIP analyses. Among transgenic mice, BAMLET treatment predicted average tumor size at censoring or death in the LSLR analysis. Specifically, among transgenic mice, the average tumor size was greatest for the 18d (μ=0.24 cm, p=0.003) and 24w BAMLET-treated (μ=0.20 cm, p=0.03) mice when compared to NS-treated controls (μ=0.12 cm).

Discussion and Conclusion: These preliminary data suggest the effect of the transgene is strong on the number of tumors the result from DMBA treatment and on survival. This strong effect suggests we lack the power to detect an effect of BAMLET in transgenic mice. However, some data herein suggest BAMLET may increase average tumor size among HPV16-E7 transgenic mice. In light of positive findings in human clinical studies using the human analogue, HAMLET, understanding whether the effects of α-Lactalbumins and oleic acid complexes are modulated by HPV E6, E7, or E6/E7 oncogenes warrants further exploration.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C31.

Abstract LB-177: HPV16 CpG and de novo-cytosine methylation is differentially associated with low-grade versus high-grade anal intraepithelial neoplasia in HIV-infected men

Objective: To determine if cytosine methylation in CpG and de novo sites is differentially associated with high- or low-grade anal intraepithelial neoplasias (HG-, LG-AIN), HPV16 DNA from182 clinical specimens. Background: Intra-anal cancer (IAC) is an emerging health crisis for gay, bisexual, transgender and other men who have sex with men (MSM) and rates have risen sharply among HIV-infected MSM despite introduction of HAART. High-risk HPVs are a causal risk factor for IAC and are especially common where MSM show HIV-coinfection. Further, cytosine methylation has been posited as an epigenetic transcription regulator that is poorly described in intra-anal dysplasias and cancers.

Methods: HPV16 DNA was extracted from anal swab specimens and tested using bisulfite modification, PCR, cloning and sequencing of ∼10 clones/sample. Cervical cancer cell lines, CaSki and SiHa, and paraffin-embedded anal cancer specimens were similarly characterized as controls. Genomic sequences were evaluated using CLUSTAL and BiQ Sequence Alignment analysis software. Descriptive, tabular and multivariate analyses were performed using SAS (Version 9.2). Graphical representations were compiled using SIGMAPLOT (Version 9.0).

Findings: Overall, methylation was relatively low in clinical AIN specimens. For 25,085 cytosines, the mean prevalence of methylation was 2.7% (SEM=0.4%) across 3′ L1 and LCR; the prevalence me-CpG, -CpA, -CpT, and -CpC was 3.2% (0.2%), 2.6% (0.1%), 2.5% (0.1%), and 2.7% (0.1%), respectively. However, some variation in HPV16 genomes was observed across specific functional gene sequences for HG- and LG-AIN specimens. Specifically, LG-AINs showed 1.30–2.62 times greater mean prevalence of methylation when compared to HG-AINs, across 24 of the 31 cytosines between nt7428–7564 (p-values&lt;0.05) in the 5′ LCR and enhancer. In total, across the 148 cytosine positions, 37 sites showed statistically significantly greater prevalence of meC in LG-AINs and none showed higher methylation in HG-AINs, yielding a false discovery rate of 0.2 (7.4/37). The nt7428–7564 contains binding sites for E2–1, TEF-1, NF-1, YY1, OCT-1, GRE and potential deamination targets for ApoBec3G. Analyses are ongoing, nonetheless, multivariate analyses show risk for HG-AIN decreases by 27% for each cumulative increase of 100% cytosine-methylation across nt7220–7558, even after we controlled for age, CD4+ T-lymphocyte count, and repeated measurements.

Conclusions: Data suggest the HPV16 5′LCR/enhancer region contains a large concentration of cytosine-containing transcription regulatory elements where binding interference by methylation might alter expression of the p97 promoter. Methylation in the HPV16 5′LCR/enhancer may decrease risk for HG-AIN.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-177. doi:10.1158/1538-7445.AM2011-LB-177

Human papillomavirus vaccine among adult women: disparities in awareness and acceptance

BACKGROUND

Human papillomavirus (HPV) vaccines have been shown to be safe and highly effective in young and middle-aged women.

PURPOSE

This study aimed to assess vaccine awareness and desire for vaccination among adult women aged 18-55 years residing in Los Angeles County CA.

METHODS

This study is nested in the 2007 Los Angeles County Health Survey. Included in the analyses were 2295 women aged 18-55 years. Logistic regression was used to evaluate vaccine awareness and intention to become vaccinated in association with various factors. All analyses employed weighted data and were conducted in 2009.

RESULTS

Only 5% of women aged 18-26 years had received the HPV vaccine in its first year on the market. Overall, 67% of women aged 18-55 years had heard of the vaccine. Among those who knew of the vaccine but had not received it, 61% reported they were likely to receive the vaccine. Latina, black, and Asian/Pacific Islander women were only half as likely to have heard of the vaccine as white women, but Latinas and Asian/Pacific Islander women were more willing to be vaccinated than white or black women. Education was associated positively with awareness, but inversely associated with intention to be vaccinated. Awareness and desire for vaccination also varied substantially by other factors such as language spoken at home.

CONCLUSIONS

This population-based study of diverse women reveals important disparities in HPV vaccine awareness and intention to be vaccinated. Culturally and linguistically competent educational campaigns about HPV immunization are warranted, and should target high-risk populations.

Abstract 2807: The relationship between age and efficiency of cervical cancer screening using population-based surveillance

Data for in situ cervical carcinomas are not routinely collected by U.S. tumor registries. Some experts suggest that comparing preinvasive and invasive cervical cancers (ICC) rates may represent our best population-based appraisal of screening strategies. From 1991-1997, a total of 5,921 women diagnosed with in situ or ICC were reported to the Markey Cancer Registry in Lexington, Kentucky, a population-based registry. Maximum-likelihood Poisson regression analyses were used to estimate the incidence rate of in situ and ICC (per 100,000), summarized over age-and race-specific groups for each of seven years, 1991 to 1997. U.S. Census age and race data for 1990 were used to estimate denominators for two race groups: African American (AA) and all others (white). Incidence rates and rate ratios are reported.

A total of 4,290 and 1,631 were diagnosed with in situ and ICC in the study period. While more than 80% of cases among women &lt;30 years of age were diagnosed as in situ lesions, only about half of cases diagnosed among 50-54 year-olds were identified at a preinvasive stage. For women &gt;65 years, only 42% (+4%) of tumors were diagnosed as in situ lesions. Specifically, among 20-39 year olds, AA were less likely than white women to be diagnosed with in situ carcinoma (p&lt;0.05), while after age 60, they were more likely than whites to be similarly diagnosed (p&lt;0.05). White women 20-49 years were 1.4-23.8 times more likely to be diagnosed with in situ carcinoma than ICC; however, AA ages 25-34 were 1.4-1.6 times more likely to show in situ disease. Whites &gt;55 were less likely to be diagnosed with in situ disease than ICC. While year of diagnosis was significant in the analyses, relationships between age and diagnostic stage persisted across each of 7 years examined.

These data suggest that Pap test most efficiently identifies treatable, high-grade precancerous lesions among women younger than 50 years. HPV infection prevalence varies by age, but not race, while ICC disproportionately affects women of color, especially as they age. Several factors may explain these findings. Screening may be performed less often overall or more inconsistently among older women and among AA. Also, if screening in the population decreases with advancing age, symptomatic older women with higher likelihood of malignancy will be over-represented in the data. Directly tailoring screening programs to recruit and retain non- and under-screened women and women with medical record evidence of poorly triaged Pap test abnormalities may improve detection of cervical cancers at a preinvasive stage, where there is a very high likelihood of survival. We believe that these findings are consistent with those of others, and together they suggest our best public health strategy may be to actively recruit middle-age and older women into cervical cancer screening programs who have undergone Pap test screening fewer than three times in a ten year period.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2807.

Anal Cancer Screening: Barriers and Facilitators Among Ethnically Diverse Gay, Bisexual, Transgender, and Other Men Who Have Sex With Men

Knowledge and beliefs about anal cancer screening among gay and other men who have sex with men remains unclear, despite data that suggests significant risk for intra-anal HPV-related cancers. Nevertheless, community-based screening activities may be most effective when stake-holder perspectives are addressed. We conducted four focus groups among 16 male and 3 female health care advocates experienced in working with diverse gay and other men who have sex with men in Los Angeles. Barriers to anal cancer screening included lack of awareness, stigma, psychological and physical discomfort, the anus as hidden/private, primary concern with HIV, and men's lack of healthcare seeking. Facilitators were community screening sites, novel strategies such as home testing, health care system changes and targeted educational campaigns, which may increase anal cancer awareness and screening among ethnically diverse men who have sex with men.

Incidence and epidemiology of anal cancer in the multicenter AIDS cohort study

OBJECTIVE

To examine the incidence and risk factors for anal cancer in a multicenter cohort of human immunodeficiency virus (HIV) positive and HIV-negative men who have sex with men followed between 1984 and 2006 (Multicenter AIDS Cohort Study).

METHODS

Prospective analysis using Poisson regression and Cox proportional hazard models and a nested case-control study using conditional logistic regression.

RESULTS

There were 28 cases of anal cancer among the 6,972 men who were evaluated. The incidence rate was significantly higher in HIV-positive men than in HIV-negative men (incidence rate = 69 vs 14 per 100,000 person-years). Among HIV-positive men, anal cancer incidence was higher in the highly active antiretroviral therapy (HAART) era than the pre-HAART era (incidence rate = 137 vs 30 per 100,000 person-years). In multivariate analysis restricted to the HAART era, anal cancer risk increased significantly with HIV infection (relative hazard = 4.7, 95% confidence interval = 1.3 to 17) and increasing number of unprotected receptive anal sex partners at the first 3 study visits (P trend = 0.03). Among HIV-positive men, current HAART use did not decrease anal cancer risk.

CONCLUSIONS

HIV-positive men had increased risk of anal cancer. Improved survival of HIV-positive individuals after HAART initiation may allow for sufficient time for human papillomavirus-associated anal dysplasias to develop into malignancies, thus explaining the increased incidence of anal cancer in the HAART era.

Cumulative perinatal steroids: child development of preterm infants

The development of premature infants may be altered due to exposure to high cumulative doses of the perinatal corticosteroid dexamethasone during critical growth periods. To compare child behavioral development of prematurely born infants who were exposed to higher perinatal steroids (PNS; >0.2 mg/kg) with that of infants exposed to lower PNS ( Collapse

Key Words

• perinatal steroids
• dexamethasone
• preterm infants
• neurodevelopment

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MESH Headings

• Adult
• Analysis of Variance
• Anthropometry
• Chi-Square Distribution
• Child
• Developmental Disabilities/chemically induced
• Developmental Disabilities/diagnosis
• Developmental Disabilities/epidemiology
• Dexamethasone/administration & dosage
• Dexamethasone/adverse effects
• Female
• Glucocorticoids/administration & dosage
• Glucocorticoids/adverse effects
• Humans
• Infant, Newborn
• Intensive Care, Neonatal
• Male
• Morbidity
• Obstetric Labor, Premature/drug therapy
• Parents/psychology
• Perinatal Care
• Pregnancy
• Prospective Studies
• Regression Analysis
• Risk Factors
• Severity of Illness Index
• Surveys and Questionnaires
• Treatment Outcome

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Grants

• T32 NR007077 NINR NIH HHS
• T32 NR007077-05 NINR NIH HHS

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Reversible deficiency of antimicrobial polypeptides in bacterial vaginosis

Bacterial vaginosis is a common condition associated with increased risk of sexually transmitted diseases, including human immunodeficiency virus infections. In contrast, vulvovaginal candidiasis has a much weaker association with sexually transmitted diseases. We found that vaginal lavage fluid from women with bacterial vaginosis is deficient in antimicrobial polypeptides and antimicrobial activity compared to fluid from healthy women or women with vulvovaginal candidiasis. Effective treatment normalized the concentrations of antimicrobial polypeptides in both bacterial vaginosis and in vulvovaginal candidiasis, suggesting that the abnormalities were a result of the diseases. Unlike in vulvovaginal candidiasis, the neutrophil attractant chemokine interleukin-8 (IL-8) was not increased in bacterial vaginosis, accounting for low concentrations of neutrophil-derived defensins in vaginal fluid. In organotypic cultures of human vaginal epithelium containing dendritic cells, treatment with Lactobacillus jensenii, a typical vaginal resident, induced the synthesis of IL-8 mRNA and the epithelial human beta-defensin-2 mRNA, but a typical bacterial vaginosis pathogen, Gardnerella vaginalis, had no effect. When the two bacteria were combined, Gardnerella vaginalis did not interfere with the immunostimulatory effect of Lactobacillus jensenii. The loss of normal immunostimulatory flora in bacterial vaginosis is thus associated with a local deficiency of multiple innate immune factors, and this deficiency could predispose individuals to sexually transmitted diseases.

Will widespread human papillomavirus prophylactic vaccination change sexual practices of adolescent and young adult women in America?

Two virus-like particle human papillomavirus (HPV) vaccines have been shown to be nearly 100% effective in preventing type-specific persistent HPV infections and associated type-specific high-grade cervical intraepithelial neoplasia (CIN). Recently, it has been hypothesized that the administration of this vaccine to young girls in the United States might increase sexual promiscuity among adolescent women and/or young adults. Thus, it has been suggested that focused vaccine strategies either based on the risk of CIN or gender might be more rational or cost-effective. However, such strategies are unlikely to completely eradicate the burden of this disease and decrease the cost of cervical cancer screening. The suggestion that widespread vaccination will alter sexual practices is refuted and the rationale for the vaccination of all girls and boys is outlined.

Smokers at Higher Risk for Undetected Antibody for Oncogenic Human Papillomavirus Type 16 Infection

OBJECTIVE

To determine the association between tobacco smoking and serologic evidence of human papillomavirus type 16 (HPV16)-specific antibodies among HPV16 DNA-positive women.

DESIGN, SETTING, AND PARTICIPANTS

Baseline health history, physical examination, and laboratory data for 205 HPV16 DNA-positive women with no prior cytologic evidence of squamous intraepithelial lesions who were enrolled subsequently in a randomized clinical trial.

MAIN OUTCOME MEASURE

HPV16-L1 antibody (anti-HPV16 antibody) detected from serum using RIA or ELISA.

RESULTS

Eighty-seven percent (179 of 205) of women tested positive for HPV16 DNA using cervicovaginal swabs or lavage specimens, and 26 women showed similar results using swab specimens of external genitalia alone. HPV16-infected women who reported increasingly greater levels of daily cigarette smoking were less likely to test positive for anti-HPV16 antibodies than nonsmoking women (P = 0.02). Smokers were twice as likely as nonsmokers to test negative for anti-HPV16 antibodies, even after controlling for the effects of other covariates in the analyses (adjusted odds ratio, 0.5; 95% confidence limits, 0.2-0.9). Although Papanicolaou test findings and smoking characteristics were poorly correlated (r(2) = 0.01), women who showed atypical cells of unknown significance or squamous intraepithelial lesion were twice as likely to test anti-HPV16 antibody positive as women who showed normal Papanicolaou tests (adjusted odds ratio, 2.0; 95% confidence limits, 1.1-3.7).

CONCLUSION

These data suggest that smoking may influence the long-term risk for cancer by perturbing early immune responses to the virus and may increase the likelihood of persistent infection. Patient education messages should alert women to this additional risk of smoking. A clinical trial of smoking cessation should be explored as a therapeutic intervention for primary HPV16 infection.

Efficacy of human papillomavirus-16 vaccine to prevent cervical intraepithelial neoplasia: a randomized controlled trial

OBJECTIVE

Human papillomavirus (HPV) virus-like particle (VLP) vaccines have demonstrated effectiveness in preventing persistent HPV infections. Whether protection lasts longer than 18 months and, thus, impacts rates of cervical intraepithelial neoplasia (CIN) 2-3 has not yet been established. We present results from an HPV16 L1 VLP vaccine trial through 48 months.

METHODS

A total of 2,391 women, aged 16-23 years, participated in a randomized, double-blind, placebo-controlled trial. Either 40 mug HPV16 L1 VLP vaccine or placebo was given intramuscularly at day 1, month 2, and month 6. Genital samples for HPV16 DNA and Pap tests were obtained at day 1, month 7, and then 6-monthly through month 48. Colposcopy and cervical biopsies were performed if clinically indicated and at study exit. Serum HPV16 antibody titer was measured by radioimmunoassay.

RESULTS

Among 750 placebo recipients in the per protocol population, 12 women developed HPV16-related CIN2-3 (6 CIN2 and 6 CIN3). Among 755 vaccine recipients, there were no cases (vaccine efficacy 100%, 95% confidence interval [CI] 65-100%). There were 111 cases of persistent HPV16 infection in placebo recipients and 7 cases in vaccine recipients (vaccine efficacy 94%, 95% CI 88-98%). After immunization, HPV16 serum antibody geometric mean titers peaked at month 7 (1,519 milli-Merck units [mMU]/mL), declined through month 18 (202 mMU/mL), and remained relatively stable between month 30 and month 48 (128-150 mMU/mL).

CONCLUSION

The vaccine HPV16 L1 VLP provides high-level protection against persistent HPV16 infection and HPV16-related CIN2-3 for at least 3.5 years after immunization. Administration of L1 VLP vaccines targeting HPV16 is likely to reduce risk for cervical cancer.

LEVEL OF EVIDENCE

I.

How condom use, number of receptive anal intercourse partners and history of external genital warts predict risk for external anal warts

Few analytic opportunities have allowed us to evaluate the role that specific sexual acts and male latex condoms play in the acquisition of external anal warts (EAW) using longitudinal data. The acquisition of EAWs occurs from epithelial contact with other HPV-infected surfaces, and hence is dependent upon sexual behaviour. Our objectives were to classify the relative importance of condom use, receptive anal intercourse (RAI) and prior history of EGWs on acquisition of EAWs. The observational Multicenter AIDS Cohort Study followed 2925 men over nine semiannual study visits for behavioural and physical examinations with laboratory testing. The main outcome measure was the occurrence of examiner-diagnosed EAWs in a homosexual population. EAWs were diagnosed among 10% of men studied across 22,157 visits reviewed for this study. Men with history of EGWs were more likely than those previously unaffected to have developed EAWs (cOR = 2.4 (2.0, 2.9)), as were men who reported multiple anoreceptive intercourse partners (e.g., compared with men who reported no RAI partners, men with 1, 2-5, > or = 6 RAI partners had crude risk ratios 1.0 (0.8, 1.3), 1.6 (1.2, 2.1), 3.9 (2.7, 5.8), respectively). These relations persisted after other demographic and sexual risk factors were controlled for in the analyses. Consistent condom usage showed no protective effect for EAWs in our crude or adjusted analyses. Patient education messages should be tailored to reflect our uncertainty about the protective nature of condoms for the development of anal warts, but to continue to assert the protective effects of a limited lifetime number of sexual partners and the heightened risk for wart recurrence once infected.

Methylation of human papillomavirus genomes in cells of anal epithelia of HIV-infected men

Intra-anal malignancies disproportionately affect individuals who engage in anal intercourse because of infection with human papillomaviruses (HPVs), with an increased risk attributed to infection with HIV because of a declining immunity against HPVs. Long-term persistence of HPVs suggests yet other mechanisms that determine the clinical outcome, however. Because methylation of HPV DNA represses oncogene expression in cervical samples, we investigated whether this mechanism also occurs in HIV-positive men and studied the methylation of CpG dinucleotides overlapping with the HPV-16 enhancer and promoter in 16 anal samples. Similar to cervical infections, the average methylation frequency was 12.3%, with heterogeneities between clones from different and the same samples. In low-grade anal intraepithelial neoplasia (AIN), methylation was high in CpGs overlapping the viral enhancer but rare in promoter positions, whereas methylation was high in promoter regions in high-grade AIN, especially in samples with a high load of viral genomes. The viral replication origin was never methylated. We also detected de novo methylation at methylated (me) CpA, meCpT, and meCpC dinucleotides. Our study expands the observation and mapping of HPV DNA methylation to anal infections and the HIV-positive patient population. As observed at the cervix, DNA methylation may force HPVs into latency with functional replication but repressed transcription. Escape from this repression is a prerequisite for neoplastic progression; however, methylation resumes because of chromosomal integration of HPV genomes but spares some HPV genomes in each cell that maintain the transformed phenotype. DNA methylation, taken together with virus load, may be useful to diagnose the emergence of a population of tumor cells.

Synaptic changes in Alzheimer's disease: increased amyloid-beta and gliosis in surviving terminals is accompanied by decreased PSD-95 fluorescence

In an effort to examine changes that precede synapse loss, we have measured amyloid-beta and a series of damage markers in the synaptic compartment of Alzheimer's disease (AD) cases. Because localization of events to the terminal region in neurons is problematic with conventional methods, we prepared synaptosomes from samples of cryopreserved human association cortex, and immunolabeled terminals with a procedure for intracellular antigens. Fluorescence was quantified using flow cytometry. The viability dye calcein AM was unchanged in AD terminals compared to controls, and the fraction of large synaptosome particles did not change, although a striking loss of large terminals was observed in some AD cases. The percent positive fraction for a series of pre- and postsynaptic markers was not affected by AD in this cohort. However, the amyloid-beta-positive fraction increased from 16 to 27% (P < 0.02) in terminals from AD cortex. The expression level on a per-terminal basis is indicated in this assay by fluorescence (relative fluorescence units). The fluorescence of presynaptic markers did not change in AD terminals, but PSD-95 fluorescence was decreased by 19% (P < 0.03). Amyloid-beta fluorescence was increased by 132% (P < 0.01), and glial fibrillary acidic protein labeling by 31% (P < 0.01). These results suggest that synapse-associated amyloid-beta is prominent in regions relatively unaffected by AD lesions, and that amyloid accumulation in surviving terminals is accompanied by gliosis and alteration in the postsynaptic structure.

Conserved methylation patterns of human papillomavirus type 16 DNA in asymptomatic infection and cervical neoplasia

DNA methylation contributes to the chromatin conformation that represses transcription of human papillomavirus type16 (HPV-16), which is prevalent in the etiology of cervical carcinoma. In an effort to clarify the role of this phenomenon in the regulation and carcinogenicity of HPV-16, 115 clinical samples were studied to establish the methylation patterns of the 19 CpG dinucleotides within the long control region and part of the L1 gene by bisulfite modification, PCR amplification, DNA cloning, and sequencing. We observed major heterogeneities between clones from different samples as well as between clones from individual samples. The methylation frequency of CpGs was measured at 14.5%. In addition, 0.21 and 0.23%, respectively, of the CpA and CpT sites, indicators of de novo methylation, were methylated. Methylation frequencies exceeded 30% in the CpGs overlapping with the L1 gene and were about 10% for most other positions. A CpG site located in the linker between two nucleosomes positioned over the enhancer and promoter of HPV-16 had minimal methylation. This region forms part of the HPV replication origin and is close to binding sites of master-regulators of transcription during epithelial differentiation. Methylation of most sites was highest in carcinomas, possibly due to tandem repetition and chromosomal integration of HPV-16 DNA. Methylation was lowest in dysplasia, likely reflecting the transcriptional activity in these infections. Our data document the efficient targeting of HPV genomes by the epithelial methylation machinery, possibly as a cellular defense mechanism, and suggest involvement of methylation in HPV oncogene expression and the early-late switch.

Cervical cancer screening

Although primary prevention of human papillomavirus (HPV) infections that are causally associated with invasive cervical cancer may be within our grasp, it is unlikely that these approaches will replace existing cervical cancer screening strategies for many years. Experts agree and data support periodic cytology screening for young-adult women using one of several technologies. Recent analyses of cost-effectiveness suggest that the addition of molecular HPV DNA testing for women aged over 30 years may allow the screening interval to be lengthened to 3 years for most women. Women at high risk for HPV infection and its associated cellular atypias warrant closer monitoring and follow-up. These patients would include organ transplant recipients, women exposed to diethylstilbestrol (DES), and HIV-infected women.

Perinatal corticosteroids: A review of research. Part I: Antenatal administration

The premature infant may receive therapeutic glucocorticoid drugs while in utero or in the postnatal period. This article (part I of a two-part series) discusses the benefits and risks of in utero, or antenatal, corticosteroids (ACS) for the premature infant. Part II addresses the benefits and risks of postnatal corticosteroid (PCS) use. There are numerous clinical studies on the therapeutic use of these steroids for the prevention of respiratory distress syndrome and chronic lung disease in the premature infant, although research results on the efficacy of repeated steroid exposure among premature infants vary. Premature infants who are exposed to repeated courses of ACS and/or high-cumulative-dose PCS may show no neurologic side effects until later in life. Research in newborn animal models focused on the timing, duration, and amounts of ACS and PCS. Current clinical research includes examination of the neurodevelopment of infants who are therapeutically exposed to perinatal corticosteroids, to identify safer minimal dose protocols. Over the past 30 years, corticosteroids have been increasingly prescribed before and after birth. Understanding the potential treatment benefits and risks to human fetuses and neonates is vital to clinical practice. This review presents historic and pharmacokinetic information about prenatal use of corticosteroids. It also offers scientific evidence of the benefits and risks identified in animal models and clinical trials, to stimulate thought that gtiides neonatal clinical practice.

Genomic diversity of human papillomavirus-16, 18, 31, and 35 isolates in a Mexican population and relationship to European, African, and Native American variants

Cervical cancer, mainly caused by infection with human papillomaviruses (HPVs), is a major public health problem in Mexico. During a study of the prevalence of HPV types in northeastern Mexico, we identified, as expected from worldwide comparisons, HPV-16, 18, 31, and 35 as highly prevalent. It is well known that the genomes of HPV types differ geographically because of evolution linked to ethnic groups separated in prehistoric times. As HPV intra-type variation results in pathogenic differences, we analyzed genomic sequences of Mexican variants of these four HPV types. Among 112 HPV-16 samples, 14 contained European and 98 American Indian (AA) variants. This ratio is unexpected as people of European ethnicity predominate in this part of Mexico. Among 15 HPV-18 samples, 13 contained European and 2 African variants, the latter possibly due to migration of Africans to the Caribbean coast of Mexico. We constructed phylogenetic trees of HPV-31 and 35 variants, which have never been studied. Forty-six HPV-31 isolates from Mexico, Europe, Africa, and the United States (US) contained a total of 35 nucleotide exchanges in a 428-bp segment, with maximal distances between any two variants of 16 bp (3.7%), similar to those between HPV-16 variants. The HPV-31 variants formed two branches, one apparently the European, the other one an African branch. The European branch contained 13 of 29 Mexican isolates, the African branch 16 Mexican isolates. These may represent the HPV-31 variants of American Indians, as a 55% prevalence of African variants in Mexico seems incomprehensible. Twenty-seven HPV-35 samples from Mexico, Europe, Africa, and the US contained 11 mutations in a 893-bp segment with maximal distances between any two variants of only 5 mutations (0.6%), including a characteristic 16-bp insertion/deletion. These HPV-35 variants formed several phylogenetic clusters rather than two- or three-branched trees as HPV-16, 18, and 31. An HPV-35 variant typical for American Indians was not identifiable. Our research suggests type specific patterns of evolution and spread of HPV-16, 18, 31, and 35 both before and after the worldwide migrations of the last four centuries. The high prevalence of highly carcinogenic HPV-16 AA variants, and the extensive diversity of HPV-18, 31, and 35 variants with unknown pathogenic properties raise the possibility that HPV intra-type variation contributes to the high cervical cancer burden in Mexico.

Rapid annexin-V labeling in synaptosomes

Distal neuronal terminals may be the site of apoptotic events and early synapse loss in neurodegenerative disease. To examine apoptosis in synaptic regions, we established a cell-free assay using a rat brain crude synaptosomal preparation (P-2 fraction) as a model system. The apoptosis marker annexin-V was used to measure phosphatidylserine (PS) exposure, and to ensure that only intact terminals were assayed, synaptosomes were dual labeled with a viability marker (calcein AM). Fluorescence was quantified by flow cytometry analysis. Annexin-V labeling increased rapidly in synaptosomes, following a 1 min incubation with staurosporine. However, increased caspase-3-like activity was not measured until 30 min with a fluorometric assay. The addition of a peptide inhibitor of caspase-3-like activity (Ac-DEVD-CHO) during homogenization was not able to block the initial increase in annexin labeling, but resulted in a partial blockade of annexin labeling after 30 min. These data demonstrate that PS externalization and caspase activation occur rapidly in this widely used neurochemical preparation.

Magnetic resonance imaging and the neonate

Over the past decade, advances in neuroimaging have given birth to a new field of diagnostic pediatric neurologic assessment that includes magnetic resonance imaging (MRI). This invaluable tool helps medical professionals to resolve many clinical and research questions related to neonatal neurodevelopment that other imaging technology cannot explain. Nurses and others who accompany infants to MRI would benefit from a better understanding of early neurodevelopment and of the neuroimaging procedure. Knowing the advantages and disadvantages of MRI techniques can help nurses be better patient advocates, parent liaisons, and caregivers to infants having MRI scans.