The Vanderbilt Nigeria Biostatistics Training Program (VN-BioStat): Results from a Skills Workshop

The Vanderbilt-Nigeria Biostatistics Training Program (VN-BioStat) aims to establish a research and training platform for biostatisticians doing HIV-related research in Nigeria, including enhancing mid-level biostatistics capacity through annual workshops. This paper describes findings from the inaugural workshop in Kano, Nigeria. Participants were surveyed before and after the workshop to assess their self-perceived familiarity with and confidence in their abilities to use statistical software and apply specific statistical techniques, as well as to gather feedback regarding the conduct of the workshop and future topic areas. Of the 23 participants enrolled in the workshop, 22 (96%) completed both pre- and post-workshop assessments. In both pre-workshop and post-workshop surveys, participants ranked their confidence in statistical skills using Likert scales. Scores were transformed to a 0-100 scale, and averages computed. Participants also shared open-ended feedback about the workshop and suggested future topic areas. Before the training, the average participant reported having either a "beginner" (30% of participants) or "moderate" (43%) level of familiarity with R. Many participants (65%) rated themselves as having "moderate" or "expert" familiarity with SPSS. Pre-workshop averages for confidence ranged from 26 to 64, with lowest confidence in "expanding continuous covariates in regression models and interpret results" and highest confidence in "fitting and interpreting results from a linear regression model". Post-workshop averages for confidence were all above 70. The lowest post-workshop score (74) was for "fit and interpret results from a semiparametric linear transformation model". The greatest increase in confidence was observed in "expanding continuous covariates in regression models using splines and interpreting results" and the lowest increase was in "fitting and interpreting results from a linear regression model." Participants offered positive feedback on instructor effectiveness (4.9/5) and overall course quality (4.9/5). While the overall course was rated on a 0-100 scale as "moderately difficult" (mean ± SD: 40.5 ± 17.5), the participants felt the course was highly organized (87.7 ± 17.8), and the information was moderately easy to learn (81.9 ± 15.9). Suggestions for future workshops included providing supplementary resources for out-of-classroom learning and releasing codes in advance to enhance participants' preparation. Among suggestions for future workshop topics, 80% of respondents listed survival analysis. Lessons learned provide insight into how short-term training opportunities can be leveraged to build biostatistics capacity in similar settings.

Training the next generation of Biostatisticians in West Africa: The Vanderbilt Nigeria Biostatistics Training Program (VN-BioStat)

Biomedical HIV research is growing in West Africa, but biostatistical expertise is lagging. The Vanderbilt-Nigeria Biostatistics Training Program (VN-BioStat) seeks to establish a research and training platform for biostatisticians doing HIV-related research in Nigeria. The objectives of the program are: 1) Host two Nigerian data scientists per year (a total of 10 over 5 years) at Vanderbilt University Medical Center to gain hands-on biostatistics training and experience via one-year fellowships. Eligible trainees will be junior investigators with PhDs or nearing completion of their PhDs in statistics or related fields, including mathematics and computer science. 2) Conduct annual workshops in Nigeria to provide biostatistics training. Trainees will undertake biostatistics coursework and hands-on training and participate in mentorship as biostatisticians involved in HIV research. Trainees will be at Vanderbilt for a full year and be part of an active biostatistics department. They will be immersed in a dry-lab HIV biostatistics project in collaboration with a Nigerian HIV research project and lead a methodologically focused research project. They will also participate in a one-month research training/grant writing program in Nashville. The VN-BioStat program will build on the existing momentum of ongoing initiatives to enhance research capacity in Nigeria by developing biostatistics leadership. VN-BioStat trainees will interact with investigators from Nigeria to provide collaborative biostatistical assistance with study design and data analysis, thus gaining real-world experience that will benefit the trainees and the broader research community in Nigeria.

LMIC Research Centers' Experiences Hosting U.S. and LMIC Trainees: Evaluation of the Fogarty Global Health Fellows and Scholars Program, 2012 to 2020

In this mixed-methods study, we explore themes that emerged from a survey assessing the programmatic experiences of mentors and administrators at institutions in low- and middle-income countries (LMICs) hosting trainees supported by the Fogarty International Center's Global Health Program for Fellows and Scholars. A total of 89 of 170 potential respondents representing 31 countries completed the survey (response rate, 52.4%). There was agreement among respondents that their institutions received sufficient funds to support trainees and had the capacity to manage operational and financial aspects of the program. A majority also agreed that both LMIC and U.S. trainees were beneficial to the host institutions, and that trainee projects were relevant to the needs of the host country. Respondents felt that program benefits to LMIC trainees could be improved by increasing the research consumables budget, increasing the flexibility of program timelines, and increasing engagement between LMIC and U.S. trainees and institutions. Respondents indicated that both U.S. and LMIC trainees behaved professionally (including demonstrating respectful and ethical behavior) and took appropriate initiative to conduct their research projects. Findings from this study will help inform innovations to similar training initiatives that will enhance sustainability and improve program performance, and will be responsive to local needs.

Etiology of Persistent Microalbuminuria in Nigeria (P_MICRO study): protocol and study design

BACKGROUND

Microalbuminuria is an independent risk factor for cardiovascular and kidney disease and a predictor of end organ damage, both in the general population and in persons with HIV (PWH). Microalbuminuria is also an important risk factor for mortality in PWH treated with antiretroviral therapy (ART). In the ongoing Renal Risk Reduction (R3) study in Nigeria, we identified a high prevalence of microalbuminuria confirmed by two measurements 4-8 weeks apart in ART-experienced, virologically suppressed PWH. Although Stage 1 or 2 hypertension and exposure to potentially nephrotoxic antiretroviral medications were common in R3 participants, other traditional risk factors for albuminuria and kidney disease, including diabetes, APOL1 high-risk genotype, and smoking were rare. Co-infection with endemic pathogens may also be significant contributors to albuminuria, but co-infections were not evaluated in the R3 study population.

METHODS

In Aim 1, we will cross-sectionally compare the prevalence of albuminuria and established kidney disease risk factors in a cohort of PWH to age- and sex-matched HIV-negative adults presenting for routine care at the Aminu Kano Teaching Hospital in Kano, Nigeria. We will leverage stored specimens from 2500 R3 participants and enroll an additional 500 PLWH recently initiated on ART (≤ 24 months) and 750 age- and sex-matched HIV-negative adults to determine the contribution of HIV, hypertension, and other comorbid medical conditions to prevalent albuminuria. In Aim 2, we will follow a cohort of 1000 HIV-positive, ART-treated and 500 HIV-negative normoalbuminuric adults for 30 months to evaluate the incidence and predictors of albuminuria.

DISCUSSION

The findings from this study will support the development of interventions to prevent or address microalbuminuria in PWH to reduce kidney and cardiovascular morbidity and mortality. Such interventions might include more intensive monitoring and treatment of traditional risk factors, the provision of renin-angiotensin aldosterone system or sodium-glucose cotransporter-2 inhibitors, consideration of changes in ART regimen, and screening and treatment for relevant co-infections.

Building Physician-Scientist Skills in R Programming:A Short Workshop Report

Introduction

Statistical analysis programs require coding experience and a basic understanding of programming, skills which are not taught as part of medical school or residency curricula.

Methods

We conducted a five-day course for early-career Nigerian physician-scientists interested in learning common statistical tests and acquiring R programming skills. The workshop included didactic presentations, small group learning activities, and interactive discussions. A baseline questionnaire captured participant demographics and solicited participants' level of confidence in understanding/performing common statistical tests. REDCap questionnaires were emailed to obtain feedback on educational format and content. A post-workshop assessment covered participants' overall impression of the program.

Results

A total of 23 participants attended the program. Most participants were male (n=14, 60.9%) and at an early stage in their career (assistant professor, n=20, 87.0%). Approximately 70% of respondents indicated having received some prior training in statistics. The proportion of participants without experience using R and SAS software (90% and 85%, respectively) was greater than the corresponding proportions for Stata (55%) and SPSS (20%). Prior to the workshop, most respondents expressed being "not at all confident" in performing one-way ANOVA (60%), logistic regression (68%), simple linear regression (60%), and McNemar's test (80%). There was a statistically significant post-workshop improvement in the level of confidence in understanding and performing common statistical tests. The course was rated on a 0-100 scale as "moderately difficult" (mean ± SD: 51.7 ± 19.5). Most participants felt comfortable in putting the knowledge learned into practice (82.2 ± 17.1).

Conclusion and Public Health Implications

Introductory R can be taught to junior physician-scientists in resource-limited settings and can inform the development and implementation of similar training initiatives in analogous settings.

Expanding Global Health Engagement through Fogarty Fellowship Programs

Training the next generation of global health researchers is vital for sustainable research partnerships and global health equity. The Fogarty International Center (National Institutes of Health) supports postdoctoral fellows and professional/graduate students in long-term, hands-on mentored research in low- and middle-income countries (LMICs). We surveyed 627 alumni (58% from the United States, 42% from LMICs) from three sequential Fogarty-sponsored global health research training programs (response rate: N = 257, 41%). Publications in the Index Medicus were used to ascertain scholarly output. Most alumni (63%) reported remaining engaged in LMICs and/or worked in academic/research careers (70%). Since completing their Fogarty fellowship, 144 alumni (56%) had received 438 new grants as principal investigator (PI), co-/multi-PI, or site PI. The 257 responding alumni had 5,318 publications during and since their Fogarty fellowships; 2,083 (39%) listed the Fogarty trainee as the first or senior author. These global health training programs highlight the value of LMIC research experience in nurturing the global health research workforce.

Building Research Capacity in HIV and Noncommunicable Diseases in Africa: A Mentorship and Leadership Workshop Report

INTRODUCTION

Few structured mentoring programs target early-stage investigators in Africa, creating a gap in mentorship skills where HIV burden is greatest. We describe findings from a Nigeria-based workshop for early-career physician scientists to build mentoring and leadership capacity in HIV and noncommunicable disease research.

METHODS

Baseline surveys captured participant demographics, confidence in implementing mentoring competencies, and perceived importance of workshop training domains. The workshop included didactic presentations, small group activities, and interactive discussions. Daily surveys evaluated sessions, and postworkshop surveys solicited overall course impressions.

RESULTS

Of the 33 participants, most were male (n = 21, 63.6%) and from medicine, laboratory sciences, and surgical specialties. "Building mentees' confidence" and "setting mentees' research goals" were ranked as areas where participants most believed they needed training. Sessions were rated favorably across five areas. Greatest improvements in mean scores were for confidence in identifying personal temperament styles, describing mentoring and leadership theories/frameworks, and developing mentoring plans. Additional identified workshop strengths were content relevance, leadership case series, interactive nature, and collegial atmosphere. All respondents indicated learning something new/useful/helpful in each session. At 6-month postworkshop, most respondents (25 of 26, 96%) had replicated or plan to replicate parts of the workshop in their departments/institutions.

DISCUSSION

Effective mentoring training initiatives targeting future academic leaders have the potential to create skilled academicians who can impart mentoring skills and competencies to their mentees.

The V-RAMP Program: Building Research Administration and Management Capacity in Nigeria

The increasing volume and complexity of research activities in Nigeria necessitates urgent measures to improve research infrastructure in grants administration and management. The Vanderbilt-Nigeria Research Administration and Management Training Program (V-RAMP) seeks to build infrastructure capacity in research administration and management and research ethics at a major teaching hospital in Nigeria. We will perform a mixed methods needs assessment of the administrative and management environment and develop an action plan to address infrastructure needs, prioritize processes, and guide program implementation. We will capacitate a newly established Office of Research Administration and improve the knowledge and skills of research administrators and grant managers via short term in-person trainings in Nashville, Tennessee and in Kano, Nigeria and through remote learning opportunities. We will enhance local administrative efficiency and performance of research ethics operations through training and mentoring of members and staff of the ethics review committee. Systematic processes to streamline protocols, including a REDCap protocol tracking database and standard operating procedures in the responsible conduct of research and rigor and reproducibility will also be developed. V-RAMP will enable the creation of a high-quality research administration environment that is knowledgeable, efficient, and compliant regarding the fiscal, management and ethical standards of sponsored research.

Strategies for Successful Clinical Trial Recruitment of People Living with HIV in Low- and Middle-Income Countries: Lessons Learned and Implementation Implications from the Nigeria Renal Risk Reduction (R3) Trial

PURPOSE OF REVIEW

Clinical trials represent a bedrock for measuring efficacy of interventions in biomedical research, but recruitment into clinical trials remains a challenge. Few data have focused on recruitment strategies from the perspective of clinical trial teams, especially in low- and middle-income countries (LMIC), where HIV is most prevalent.

RECENT FINDINGS

We summarized data from the literature and our experience with recruitment for the Renal Risk Reduction trial, aimed at reducing risk of kidney complications among people living with HIV in Nigeria. Using an implementation science framework, we identified strategies that contributed to successful clinical trial recruitment. For strategies that could not be categorized by this framework, we summarized key features according to selected action, actor, target, context, and time. We identified how these identified strategies could map to subsequent implementation outcomes at the patient and provider/health system level, as well as capacity-building efforts to meet needs identified by LMIC partners, which is a priority for success. Our experience highlights the importance of considering implementation outcomes, and the strategies necessary to achieve those outcomes early, in the planning and execution of clinical trials. Clinical trial recruitment can be optimized via methodologies grounded in implementation science.

Apolipoprotein-1 risk variants and associated kidney phenotypes in an adult HIV cohort in Nigeria

HIV-positive adults are at risk for various kidney diseases, and apolipoprotein 1 (APOL1) high-risk genotypes increase this risk. This study aimed to determine the prevalence and ethnic distribution of APOL1 risk genotypes among a cohort of HIV-positive Nigerian adults and explore the relationship between APOL1 risk variant status with albuminuria and estimated glomerular filtration rate (eGFR). We conducted a cross-sectional study among 2 458 persons living with HIV who attended an HIV clinic in northern Nigeria and had received antiretroviral therapy for a minimum of six months. We collected two urine samples four-eight weeks apart to measure albumin excretion, and blood samples to measure eGFR and determine APOL1 genotype. The frequency of APOL1 high-risk genotype was 6.2%, which varied by ethnic group: Hausa/Fulani (2.1%), Igbo (49.1%), and Yoruba (14.5%). The prevalence of microalbuminuria (urine/albumin creatinine ratio 30- 300 mg/g) was 37%, and prevalence of macroalbuminuria (urine/albumin creatinine ratio over 300 mg/g) was 3%. The odds of microalbuminuria and macroalbuminuria were higher for participants with the APOL1 high-risk genotype compared to those carrying the low-risk genotype ([adjusted odds ratio 1.97, 95% confidence interval 1.37-2.82] and [3.96, 1.95-8.02] respectively). APOL1 high-risk genotype participants were at higher risk of having both an eGFR under 60 ml/min/1.73m2 and urine/albumin creatinine ratio over 300 mg/g (5.56, 1.57-19.69). Thus, we found a high proportion of HIV-positive, antiretroviral therapy-experienced, and largely virologically suppressed adults had microalbuminuria. Hence, although the high-risk APOL1 genotype was less prevalent than expected, it was strongly associated with some level of albuminuria.

HIV-associated nephropathy: Protocol and rationale for an exploratory genotype-phenotype study in a sub-Saharan African population

BACKGROUND

HIV-positive persons of African descent are disproportionately affected by chronic kidney disease (CKD). Deterioration to end-stage kidney disease (ESKD) also occurs in this population at a higher frequency. There remains a lot to learn about the genetic susceptibility to CKD in HIV positive patients, and the pathophysiology of progression to ESKD.

OBJECTIVES

We will conduct an exploratory genotype-phenotype study in HIV-positive persons with CKD in Aminu Kano Teaching Hospital, Nigeria, to determine blood-based differential gene expression biomarkers in different kidney risk groups according to the KDIGO 2012 criteria.

METHODS

We will consecutively screen 150 HIV-positive adults (≥18 years of age) attending the HIV clinic of Aminu Kano Teaching Hospital, Kano, Nigeria, for CKD based on proteinuria and elevation of estimated glomerular filtration rate. Among these, two separate groups of 16 eligible participants each (n = 32) will be selected in the four (4) KDIGO 2012 kidney risk categories. The groups will be matched for age, sex, viral suppression level and antiretroviral (ARV) regimen. In the first group (n = 16), we will determine differential gene expression markers in peripheral blood mononuclear cells using mRNA-sequencing (RNA-Seq). We will validate the differential expression markers in the second group (n = 16) using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Using a systems-based approach, we will construct, visualize and analyze gene-gene interaction networks to determine the potential biological roles of identified differential expression markers based on published literature and publicly available databases.

RESULTS

Our exploratory study will provide valuable information on the potential roles of differential expression biomarkers in the pathophysiology of HIV-associated kidney disease by identifying novel biomarkers in different risk categories of CKD in a sub-Saharan African population. The results of this study will provide the basis for population-based genome-wide association studies to guide future personalized medicine approaches.

CONCLUSION

Validated biomarkers can be potential targets for the development of stage-specific therapeutic interventions, an essential paradigm in precision medicine.

The V-BRCH Project: building clinical trial research capacity for HIV and noncommunicable diseases in Nigeria

Antiretroviral therapy has turned HIV into a chronic condition, with morbidity from HIV-associated noncommunicable diseases (NCDs) becoming more common as HIV-infected individuals live longer. In Nigeria, the additional challenge of an under-capacitated health system highlights the need for skilled clinical investigators who can generate evidence to tackle the double burden of HIV and NCDs. The Vanderbilt-Nigeria Building Research Capacity in HIV and Non-communicable Diseases (V-BRCH) programme is a training platform to create a cohort of skilled Nigerian investigators with the capacity to lead independent clinical trial research focused on the intersection of HIV and NCDs. V-BRCH will solidify an atmosphere of continuous mentoring and skills acquisition for physician faculty at the Aminu Kano Teaching Hospital via short- and medium-term learning opportunities, paired mentoring arrangements, and mentored research projects. Trainees will attend an annual faculty enrichment programme in Nashville, in addition to on-site workshops in Nigeria on HIV-associated NCD epidemiology, clinical trials methodology, evidence synthesis, qualitative research methods, stakeholder engagement, knowledge translation, and grant writing. Research-oriented junior faculty will undergo focused training in clinical trials administration and regulatory oversight. Scholars will share best practices through mentoring panels, regular ‘Works in Progress’ meetings, and monthly career development seminars. Competitive seed grants will be provided to mentor–mentee teams to promote targeted in-country pilot studies focused on HIV-associated NCDs. For long-term training, physician scientists will be supported to undergo enhanced Master of Public Health (MPH) training at Bayero University in Nigeria and Master of Science in Clinical Investigation (MSCI) training at Vanderbilt. Short-term regional courses, staff development workshops, and MPH curriculum refinement will help to strengthen institutional capacity in HIV-associated NCD clinical trial research. V-BRCH will create a cohort of skilled Nigerian scientists who will be able to compete for independent funding and design and implement high quality research that will generate evidence to inform policy and practice and lead to improved outcomes for Nigerians impacted by HIV-associated NCDs.

Recurrence of Genital Infections With 9 Human Papillomavirus (HPV) Vaccine Types (6, 11, 16, 18, 31, 33, 45, 52, and 58) Among Men in the HPV Infection in Men (HIM) Study

Background

The purpose of this study was to assess genital recurrence of human papillomavirus (HPV) genotypes included in the 9-valent vaccine and to investigate factors associated with recurrence among men in the HPV Infection in Men (HIM) Study.

Methods

Men were followed every 6 months for a median of 3.7 years. HPV genotypes were detected using Roche linear array. Factors associated with type-specific HPV recurrence (infections occurring after a ≥12-month infection-free period) were assessed.

Results

In type-specific analyses, 31% of prior prevalent and 20% of prior incident infections recurred. Among prevalent infections, HPV types 52, 45, 16, 58, and 6 and among incident infections, HPV types 58, 52, 18, 16, and 11 had the highest rates of recurrence. New sexual partners (male or female) and frequency of sexual intercourse with female partners were associated with HPV-6, -16, -31, and -58 infection recurrence. In grouped analyses, lifetime and new male sexual partners were associated with recurrence of prior incident infection with any of the 9 HPV types.

Conclusions

Recurrence of genital HPV infections is relatively common among men and associated with high-risk sexual behavior. Further studies are needed to understand the role of HPV recurrence in the etiology of HPV-associated diseases.

Optimal management of HIV- positive adults at risk for kidney disease in Nigeria (Renal Risk Reduction "R3" Trial): protocol and study design

Background

Individuals with two copies of the apolipoprotein-1 (APOL1) gene risk variants are at high risk (HR) for non-diabetic kidney disease. The presence of these risk variants is highest in West Africa, specifically in Nigeria. However, there is limited availability of dialysis and kidney transplantation in Nigeria, and most individuals will die soon after developing end-stage renal disease. Blocking the renin angiotensin aldosterone system with angiotensin-converting enzyme inhibitors (ACEi) is a well-recognized strategy to slow renal disease progression in patients with diabetes mellitus with chronic kidney disease (CKD) and in patients with HIV-associated nephropathy. We propose to determine whether presence of the APOL1 HR genotype alters or predicts responsiveness to conventional therapy to treat or prevent CKD and if addition of an ACEi to standard combination antiretroviral therapy (ART) reduces the risk of kidney complications among non-diabetic Nigerian adults.

Methods/design

We will screen 2600 HIV-positive adults who have received ART to (1) determine the prevalence of APOL1 risk variants and assess whether APOL1 HR status correlates with prevalent albuminuria, estimated glomerular filtration rate (eGFR), and/or prevalent CKD; (2) assess, via a randomized, placebo-controlled trial (RCT) in a subset of these participants with microalbuminura (n = 280) whether addition of the ACEi, lisinopril, compared to standard of care, significantly reduces the incidence or progression of albuminuria; and (3) determine whether the APOL1 HR genotype is associated with worse kidney outcomes (i.e. eGFR slope or regression of albuminuria) among participants in the RCT.

Conclusions

This study will examine the increasing prevalence of kidney diseases in HIV-positive adults in a West African population, and the relationship between these diseases and the APOL1 high-risk genotype. By evaluating the addition of an ACEi to the care of individuals with HIV infection who have albuminuria, our trial will provide definitive evidence to guide strategies for management and clinical care in this population, with the goal of reducing HIV-related kidney complications.

Trial registration

ClinicalTrials.gov, NCT03201939. Registered on 26 August 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3436-y) contains supplementary material, which is available to authorized users.

Bridging the childhood epilepsy treatment gap in northern Nigeria (BRIDGE): Rationale and design of pre-clinical trial studies

Epilepsy is the most common serious childhood neurological disorder. In the low- and middle-income countries (LMICs) of Africa, children with epilepsy suffer increased morbidity and mortality compared to their counterparts in high-income countries, and the majority do not receive treatment - the childhood epilepsy treatment gap. Reports of the childhood epilepsy treatment gap in Africa are likely underestimates; most surveys do not include several common childhood seizure types, including most types of non-convulsive epilepsy. Efforts to scale up childhood epilepsy care services in the LMICs of Africa must contend with a shortage of physicians and diagnostic technology [e.g., electroencephalograms (EEGs)]. One pragmatic solution is to integrate epilepsy care into primary care by task-shifting to community health extension workers. The aims of this project (BRIDGE) are to: 1) train, develop, and pilot task-shifted epilepsy care teams; 2) develop and pilot innovative childhood epilepsy screening and diagnostic paradigms adapted to the local Hausa language/culture in Kano, northern Nigeria; and, 3) quantify and map the childhood epilepsy treatment gap, using geographic information systems (GIS), to target limited resources to areas of greatest need. Task-shifted teams will diagnose and manage childhood epilepsy using an innovative epilepsy screening tools and diagnostic and management paradigms in environments with limited EEG access. If validated and demonstrated efficacious in clinical trials, this project can be taken to scale across broader areas of west Africa's LMICs that share language and culture. BRIDGE has the potential to enhance access to basic childhood epilepsy care and establish the foundation for childhood epilepsy clinical trials in west Africa.

Country-specific HPV-related genital disease among men residing in Brazil, Mexico and The United States: The HIM study

The purpose of this study was to assess whether the incidence of histopathologically confirmed condyloma and penile intraepithelial neoplasia (PeIN) and rates of genital HPV infection progression to these lesions differs by country (Brazil, Mexico and the U.S.). At each visit, lesions were biopsied and were categorized by pathologic diagnoses. The Linear Array genotyping method was used to identify HPV genotypes from genital swabs, while the INNO-LiPA HPV Genotyping Extra method was used for tissue specimens. Age-specific analyses were conducted for lesion incidence by country, with Kaplan-Meier estimation of cumulative incidence. The proportion of HPV infections that progressed to condyloma and PeIN, the median time to lesion development and the incidence rates were estimated by country. When comparing demographic and sexual characteristics across the three countries, sexual orientation (p = 0.008) and lifetime number of female sexual partners (p < 0.0001) were differentially associated with lesion incidence in the three countries. Condyloma incidence in Brazil and the U.S. decreased with age, while incidence remained constant across the lifespan in Mexico. There were no differences by country and age for PeIN incidence. HPV types 6 and 11 were the most common types to progress to condyloma and HPV types 16, 6 and 11 were the most common types to progress to PeIN in all three countries. The continuous risk of condyloma and PeIN across all age groups and countries in this study emphasizes the need to ensure that strong HPV immunity, such as that obtained through vaccination, is maintained across the lifespan of men.

Seroprevalence of cutaneous human papillomaviruses (HPVs) among men in the multinational HPV Infection in Men study

Data on cutaneous human papillomavirus (HPV) seroprevalence are primarily derived from skin cancer case-control studies. Few studies have reported the seroprevalence of cutaneous HPV among healthy men. This study investigated the seroprevalence of cutaneous HPV types and associated risk factors among men residing in Brazil, Mexico and the USA. Six hundred men were randomly selected from the HPV Infection in Men study. Archived serum specimens were tested for antibodies against 14 cutaneous HPV genotypes, β-HPV types (5/8/12/14/17/22/23/24/38/48), α-HPV 27, γ-HPV 4, µ-HPV1 and ν-HPV 41 using a glutathione S-transferase L1-based multiplex serology assay. Risk factor data were collected by a questionnaire. Binomial proportions were used to estimate seroprevalence, and logistic regression to examine factors associated with seropositivity. Overall, 65.4 % of men were seropositive to ≥1 of the 14 cutaneous HPV types, and 39.0 % were positive for ≥1 β-HPV types. Seroprevalence was 8.9, 30.9, 28.6 and 9.4 % for α-HPV 27, γ-HPV 4, µ-HPV 1 and ν-HPV 41, respectively. In multivariate analyses, seropositivity for any cutaneous HPV type was associated with higher education [adjusted odds ratio (AOR) 1.75; 95 % confidence interval (CI) 1.08-2.83], and seropositivity of any β-HPV type was significantly associated with increasing age (AOR 1.72; 95 % CI 1.12-2.63, for men aged 31-44 years vs men aged 18-30 years). Other factors associated with various type-specific cutaneous HPV seropositivity included country, circumcision and lifetime number of male sexual partners. These data indicate that exposure to cutaneous HPV is common. Future studies are needed to assess the role of cutaneous HPV in diseases.

Impact of Serum Antibodies to HPV Serotypes 6, 11, 16, and 18 to Risks of Subsequent Genital HPV Infections in Men: The HIM Study

Naturally induced serum antibodies against human papillomavirus (HPV) may affect risks of subsequent incident genital infections by HPV 6, 11, 16, or 18 in men. In this study, we examined the hypothesis by following 4,123 healthy men every 6 months (median follow-up time, 4.1 years). HPV antibodies were measured at baseline using a virus-like particle-based ELISA assay. Genital HPV genotypes were detected using Roche Linear Array. Incidence proportions and 6-month persistence proportions were calculated at 6-month intervals. Kaplan-Meier curves and Cox models were used to assess genotype-specific cumulative incidence and HRs, respectively. HPV 6, 11, 16, and 18 seroprevalence was 8.1%, 13.9%, 12.7%, and 10.8%, respectively. Significantly higher rates of incident infections were observed for HPV 16 among baseline-seropositive men [adjusted HR, 1.37; 95% confidence interval (CI), 1.01-1.86], with similar but nonsignificant HRs for 6-month persistent infections. Risk of persistent HPV 18 infection was significantly lower among seropositive men in the unadjusted model (HR, 0.22; 95% CI, 0.06-0.91), but not in the adjusted model (HR, 0.19; 95% CI, 0.03-1.37). Incident and 6-month persistent infections for HPV 6 and 11 did not differ by baseline serostatus. Baseline serostatus among men was not associated with a reduction in subsequent incident genital HPV 6, 11, and 16 infections. However, protection against persistent HPV18 infections was observed in unadjusted models. Our research suggests a need of further studies to examine the potentially protective effects of naturally induced HPV18 antibodies in men. Cancer Res; 76(20); 6066-75. ©2016 AACR.

Distribution and factors associated with salivary secretory leukocyte protease inhibitor concentrations

OBJECTIVES

This cross-sectional study examined the distribution and correlates of salivary secretory leukocyte protease inhibitor (SLPI) concentrations within a multinational cohort of men.

METHODS

Extracellular SLPI was measured in oral gargle cell supernatants of 378 men from three countries using an ELISA-based assay. Risk factor data were collected by a questionnaire. Factors associated with SLPI were assessed using linear and logistic regression for continuous and categorical SLPI, respectively.

RESULTS

Among men aged 18-73 years, the median SLPI concentration was 492.0 ng ml^-1 (range: 2.3-1919.9). In multivariable modeling, men in Brazil and younger men (18-30 years) were more likely to have higher levels of SLPI [adjusted odds ratio (aOR) 3.84; 95% confidence interval (CI): 1.94-7.59, and aOR 3.84; 95% CI: 1.98-7.43, respectively]. Men with a self-reported sexually transmitted diseases diagnosis in the past 6 months were more likely to have higher SLPI levels (aOR 2.98; 95% CI: 1.1-7.83) and men reporting bleeding/swollen gums were less likely to have higher SLPI (aOR 0.34; 95% CI: 0.15-0.79). Similar results were observed for linear regression models.

CONCLUSIONS

Secretory leukocyte protease inhibitor concentrations varied significantly by country and decreased with increasing age. The interaction between SLPI, modifiable factors, and oral infections that influence cancer risk warrants further investigation.

Incidence, Duration, Persistence, and Factors Associated With High-risk Anal Human Papillomavirus Persistence Among HIV-negative Men Who Have Sex With Men: A Multinational Study

BACKGROUND

Given high rates of anal disease, we investigated the natural history of high-risk anal human papillomavirus (HPV) among a multinational group of men who have sex with men (MSM) aged 18-64 years.

METHODS

Anal specimens from human immunodeficiency virus-negative men from Brazil, Mexico, and the United States were genotyped. Over 2 years, 406 MSM provided evaluable specimens every 6 months for ≥2 visits. These men were stratified into men who have sex only with men (MSOM, n = 70) and men who have sex with women and men (MSWM, n = 336). Persistence was defined as ≥12 months' type-specific duration and could begin with either a prevalent or incident infection. Prevalence ratios and 95% confidence intervals were calculated by Poisson regression.

RESULTS

Median follow-up time was 2.1 years. Retention was 82%. Annual cumulative incidence of 9-valent vaccine types was 19% and 8% among MSOM and MSWM, respectively (log-rank P = .02). Duration of anal HPV did not differ for MSOM and MSWM and was a median of 6.9 months for HPV-16 after combining men from the 2 groups. Among men with prevalent high-risk infection (n = 106), a total of 36.8%, retained the infection for at least 24 months. For those with prevalent HPV-16 (n = 27), 29.6% were persistent for at least 24 months. Persistence of high-risk HPV was associated with number of male anal sex partners and inversely associated with number of female sex partners.

CONCLUSIONS

MSM with prevalent high-risk HPV infection should be considered at increased risk for nontransient infection.

Salivary secretory leukocyte protease inhibitor (SLPI) and head and neck cancer: The Cancer Prevention Study II Nutrition Cohort

OBJECTIVES

Secretory leukocyte protease inhibitor (SLPI) is an innate-immunity protein displaying antimicrobial and anti-inflammatory properties that is found in high concentrations in saliva. The role of extracellular salivary SLPI in head and neck squamous cell carcinoma (HNSCC) remains unclear. Thus, we aimed to evaluate the association between SLPI and HNSCC risk in the Cancer Prevention Study II Nutrition Cohort.

MATERIALS AND METHODS

Among 53,180 men and women with no history of cancer who provided an oral rinse between 2001 and 2002, 60 were subsequently diagnosed with incident HNSCC between specimen collection and June 2009. In this nested case-control study, archived oral supernatants were evaluated using the Human SLPI Quantikine ELISA Kit for all 60 cases and 180 controls individually matched on gender, race, date of birth, and date of oral rinse collection. Conditional logistic regression was used to estimate HNSCC risk.

RESULTS

Overall, pre-diagnostic salivary SLPI was associated with a non-statistically significant higher risk of HNSCC (OR=1.6, 95% CI=0.9-3.0). Among never smokers, high SLPI was associated with a non-statistically significant lower risk (OR=0.5, 95% CI=0.1-1.9), whereas among ever smokers, high SLPI was associated with a statistically significant higher risk (OR=2.1, 95% CI=1.0-4.3) of HNSCC, compared to low SLPI.

CONCLUSION

While results from this study suggest that higher concentrations of salivary SLPI might increase the risk of HNSCC among ever smokers, more research is needed to verify these findings and define the mechanisms by which SLPI and smoking influence the etiology of HNSCC.

Seroconversion Following Anal and Genital HPV Infection in Men: The HIM Study

Background

Protection from naturally acquired human papillomavirus (HPV) antibodies may influence HPV infection across the lifespan. This study describes seroconversion rates following genital, anal, and oral HPV 6/11/16/18 infections in men and examines differences by HPV type and anatomic site.

Methods

Men with HPV 6/11/16/18 infections who were seronegative for those genotypes at the time of DNA detection were selected from the HPV Infection in Men (HIM) Study. Sera specimens collected ≤36 months after detection were analyzed for HPV 6/11/16/18 antibodies using a virus-like particle-based ELISA. Time to seroconversion was separately assessed for each anatomic site, stratified by HPV type.

Results

Seroconversion to ≥1 HPV type (6/11/16/18) in this sub-cohort (N=384) varied by anatomic site, with 6.3%, 18.9%, and 0.0% seroconverting following anal, genital, and oral HPV infection, respectively. Regardless of anatomic site, seroconversion was highest for HPV 6 (19.3%). Overall, seroconversion was highest following anal HPV 6 infection (69.2%). HPV persistence was the only factor found to influence seroconversion.

Conclusions

Low seroconversion rates following HPV infection leave men susceptible to recurrent infections that can progress to HPV-related cancers. This emphasizes the need for HPV vaccination in men to ensure immune protection against new HPV infections and subsequent disease.

An analysis of HPV infection incidence and clearance by genotype and age in men: The HPV Infection in Men (HIM) Study

OBJECTIVES

Genital HPV infection in men causes benign and cancerous lesions, the incidence of which differs by age. The goal of this work was to comprehensively evaluate incidence and clearance of individual HPV genotypes among men by age group.

METHODS

HIV-negative men ages 18-70 with no history of anogenital cancer were recruited for the HPV Infection in Men (HIM) Study. Participants completed clinical exams and questionnaires every six months for up to ~4 years. Genital specimens underwent HPV genotyping, with associations between age and HPV assessed using Cox analyses.

RESULTS

4085 men were followed for a median of 48.6 months (range: 0.3-94.0). Significantly lower HPV incidence rates were observed among the oldest age group (55-70 years) for grouped high-risk (incidence rate ratio [IRR]=0.71), HPV16 (IRR=0.54), grouped low-risk (IRR=0.74), and HPV6 (IRR=0.57) infections compared to men ages 18-24. However, incidence of the grouped 9-valent HPV vaccine types remained constant across the lifespan. Likelihood of HPV6 and HPV16 clearance remained constant until age 54, then increased significantly for men ages 55-70 (adjusted hazard ratio [AHR]=1.92 and 1.65, respectively).

CONCLUSIONS

Men remain susceptible to HPV infections throughout their lifespan, highlighting the need for prevention efforts with long-lasting duration.

Genital Human Papillomavirus Infection Progression to External Genital Lesions: The HIM Study

BACKGROUND

Human papillomavirus (HPV) causes two types of external genital lesions (EGLs) in men: genital warts (condyloma) and penile intraepithelial neoplasia (PeIN).

OBJECTIVE

The purpose of this study was to describe genital HPV progression to a histopathologically confirmed HPV-related EGL.

DESIGN, SETTING, AND PARTICIPANTS

A prospective analysis nested within the HPV Infection in Men (HIM) study was conducted among 3033 men. At each visit, visually distinct EGLs were biopsied; the biopsy specimens were subjected to pathologic evaluation and categorized by pathologic diagnoses. Genital swabs and biopsies were used to identify HPV types using the Linear Array genotyping method for swabs and INNO-LiPA for biopsy specimens.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

EGL incidence was determined among 1788 HPV-positive men, and cumulative incidence rates at 6, 12, and 24 mo were estimated. The proportion of HPV infections that progressed to EGL was also calculated, along with median time to EGL development.

RESULTS AND LIMITATIONS

Among 1788 HPV-positive men, 92 developed an incident EGL during follow-up (9 PeIN and 86 condyloma). During the first 12 mo of follow-up, 16% of men with a genital HPV 6 infection developed an HPV 6-positive condyloma, and 22% of genital HPV 11 infections progressed to an HPV 11-positive condyloma. During the first 12 mo of follow-up, 0.5% of men with a genital HPV 16 infection developed an HPV 16-positive PeIN. Although we expected PeIN to be a rare event, the sample size for PeIN (n=10) limited the types of analyses that could be performed.

CONCLUSIONS

Most EGLs develop following infection with HPV 6, 11, or 16, all of which could be prevented with the 4-valent HPV vaccine.

PATIENT SUMMARY

In this study, we looked at genital human papillomavirus (HPV) infections that can cause lesions in men. The HPV that we detected within the lesions could be prevented by a vaccine.

Role of histological findings and pathologic diagnosis for detection of human papillomavirus infection in men

Early HPV infection in males is difficult to detect clinically and pathologically. This study assessed histopathology in diagnosing male genital HPV. External genital lesions (n = 352) were biopsied, diagnosed by a dermatopathologist, and HPV genotyped. A subset (n = 167) was diagnosed independently by a second dermatopathologist and also re-evaluated in detail, tabulating the presence of a set of histopathologic characteristics related to HPV infection. Cases that received discrepant diagnoses or HPV-related diagnoses were evaluated by a third dermatopathologist (n = 163). Across dermatopathologists, three-way concordance was fair (k = 0.30). Pairwise concordance for condyloma was fair to good (k = 0.30-0.67) and poor to moderate for penile intraepithelial neoplasia (k = -0.05 to 0.42). Diagnoses were 44-47% sensitive and 65-72% specific for HPV 6/11-containing lesions, and 20-37% sensitive and 98-99% specific for HPV 16/18. Presence of HPV 6/11 was 75-79% sensitive and 35% specific for predicting pathologic diagnosis of condyloma. For diagnosis of penile intraepithelial neoplasia, HPV 16/18 was 95-96% specific but only 40-64% sensitive. Rounded papillomatosis, hypergranulosis, and dilated vessels were significantly (P < 0.05) associated with HPV 6/11. Dysplasia was significantly (P = 0.001) associated with HPV 16/18. Dermatopathologists' diagnoses of early male genital HPV-related lesions appear discordant with low sensitivity, while genotyping may overestimate clinically significant HPV-related disease. Rounded papillomatosis, hypergranulosis, and dilated vessels may help establish diagnosis of early condyloma.

Long-term persistence of oral human papillomavirus type 16: the HPV Infection in Men (HIM) study

Persistent infection with oral HPV16 is believed to drive the development of most oropharyngeal cancers. However, patterns of oral HPV16 persistence remain understudied, particularly among HIV-negative individuals. Oral HPV16 persistence was evaluated among 1,626 participants of the HPV Infection in Men (HIM) Study. Twenty-three oral HPV16-positive men who provided an oral gargle sample on ≥2 study visits were included in the analysis. Archived oral samples from all follow-up visits were tested for HPV16 using Linear Array and INNO-LiPA detection methods. Persistence was evaluated using consecutive HPV16-positive visits held approximately 6 months apart and using the Kaplan-Meier method. Oral HPV16-positive men were aged 18 to 64 years [median, 36 years; interquartile range (IQR), 25-42] and were followed for a median of 44.4 months (IQR, 29.9-49.5). Of 13 incident infections, 4 (30.8%) persisted ≥12 months, 1 (10.0%) persisted ≥24 months, and none persisted ≥36 months [median infection duration, 7.3 months; 95% confidence interval (CI), 6.4-NA)]. Of 10 prevalent infections, 9 (90.0%) persisted ≥12 months, 8 (80.0%) persisted ≥24 months, 4 (57.1%) persisted ≥36 months, and 2 (40.0%) persisted ≥48 months (median infection duration, NA). Twelve-month persistence of incident infections increased significantly with age (Ptrend = 0.028). Prevalent oral HPV16 infections in men persisted longer than newly acquired infections, and persistence appeared to increase with age. These findings may explain the high prevalence of oral HPV observed at older ages. Understanding oral HPV16 persistence will aid in the identification of men at high-risk of developing HPV-related oropharyngeal cancer.

Human papillomavirus virus (HPV) genotype- and age-specific analyses of external genital lesions among men in the HPV Infection in Men (HIM) Study

BACKGROUND

Human papillomavirus (HPV) causes external genital lesions (EGLs) in men, including condyloma and penile intraepithelial neoplasia (PeIN). We sought to determine the incidence of pathologically confirmed EGLs, by lesion type, among men in different age groups and to evaluate the HPV types that were associated with EGL development.

METHODS

HPV Infection in Men (HIM) study participants who contributed ≥2 visits from 2009-2013 were included in the biopsy cohort. Genotyping by an HPV line-probe assay was performed on all pathologically confirmed EGLs. Age-specific analyses were conducted for incident EGLs, with Kaplan-Meier estimation of cumulative incidence.

RESULTS

This biopsy cohort included 2754 men (median follow-up duration, 12.4 months [interquartile range, 6.9-19.2 months]). EGLs (n = 377) were pathologically confirmed in 228 men, 198 of whom had incident EGLs. The cumulative incidence of any EGL was highest among men <45 years old and, for condyloma, decreased significantly over time with age. The genotype-specific incidence of EGL varied by pathological diagnoses, with high- and low-risk genotypes found in 15.6% and 73.2% of EGLs, respectively. Condyloma primarily contained HPV 6 or 11. While PeIN lesions primarily contained HPV 16, 1 PeIN III lesion was positive for HPV 6 only.

CONCLUSION

Low- and high-risk HPV genotypes contribute to the EGL burden. Men remain susceptible to HPV-related EGLs throughout the life span, making it necessary to ensure the longevity of immune protection against the most common causative HPV genotypes.

Cutaneous human papillomavirus types detected on the surface of male external genital lesions: a case series within the HPV Infection in Men Study

BACKGROUND

Cutaneous human papillomaviruses (HPVs) may be associated with cutaneous epithelial lesions and non-melanoma skin cancers. No study has systematically evaluated the presence of genus beta [β]-HPV in male genital skin or external genital lesions (EGLs)

OBJECTIVES

To examine cutaneous β-HPV types detected on the surface of EGLs in men and describe their presence prior to EGL development.

STUDY DESIGN

A retrospective case series was conducted among 69 men with pathologically confirmed EGLs (n=72) who participated in the HPV Infection in Men Study. Archived exfoliated cells collected from the surface of each EGL and normal genital skin specimens 6-12 months preceding EGL development were tested for β-HPV DNA using a type-specific multiplex genotyping assay.

RESULTS

β-HPV DNA was detected on 61.1% of all EGLs, with types 38 (16.7%), 5 (15.3%), and 12 (12.5%) most commonly identified. HPV prevalence differed across pathological diagnoses, with the largest number of β-HPV types detected on condylomas. Most β-HPV types were detected on normal genital skin prior to EGL development, though the prevalence was lower on EGLs compared to preceding normal genital skin.

CONCLUSIONS

EGLs and the normal genital skin of men harbor a large number of β-HPV types; however, it appears that β-HPVs are unrelated to EGL development in men. Despite evidence to support a causal role in skin carcinogenesis at UVR-exposed sites, cutaneous HPV appears unlikely to cause disease at the UVR-unexposed genitals.

Differential antibacterial properties of the MurA inhibitors terreic acid and fosfomycin

Terreic acid is a metabolite with antibiotic properties produced by the fungus Aspergillus terreus, but its cellular target remains unknown. We recently reported that terreic acid inactivates the bacterial cell wall biosynthetic enzyme MurA in vitro by covalent reaction with residue Cys115 in a similar manner as the MurA-specific antibiotic fosfomycin. To address if terreic acid also targets MurA in vivo, we conducted antibacterial studies using selected E. coli strains in parallel with fosfomycin. While overexpression of MurA conferred resistance to fosfomycin, it did not protect cells treated with terreic acid. Furthermore, flow cytometry revealed that the antibiotic action of terreic acid appears to be primarily bacteriostatic, as opposed to the bactericidal action observed for fosfomycin. Combined, the data suggest that MurA is not the molecular target of terreic acid and that the antibiotic activity of terreic acid proceeds through a different mechanism of action. The methodology applied here provides a reliable and convenient tool to rapidly assess the potential of newly discovered in vitro inhibitors to target residue Cys115 of MurA in the cell.

A novel approach to the discovery of small-molecule ligands of CDK2

In an attempt to identify novel small-molecule ligands of cyclin-dependent kinase 2 (CDK2) with potential as allosteric inhibitors, we have devised a robust and cost-effective fluorescence-based high-throughput screening assay. The assay is based on the specific interaction of CDK2 with the extrinsic fluorophore 8-anilino-1-naphthalene sulfonate (ANS), which binds to a large allosteric pocket adjacent to the ATP site. Hit compounds that displace ANS directly or indirectly from CDK2 are readily classified as ATP site binders or allosteric ligands through the use of staurosporine, which blocks the ATP site without displacing ANS. Pilot screening of 1453 compounds led to the discovery of 12 compounds with displacement activities (EC(50) values) ranging from 6 to 44 μM, all of which were classified as ATP-site-directed ligands. Four new type I inhibitor scaffolds were confirmed by X-ray crystallography. Although this small compound library contained only ATP-site-directed ligands, the application of this assay to large compound libraries has the potential to reveal previously unrecognized chemical scaffolds suitable for structure-based design of CDK2 inhibitors with new mechanisms of action.