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Fulltext Evidence and impact of human papillomavirus latency

Gravitt PE

Open Virol J, 2012;6:198-203.
PMID: 23341855 DOI: 10.2174/1874357901206010198

At present, there is no consensus in the scientific community regarding the ability for human papillomavirus (HPV) infections to establish latency. Based on animal studies, a model of papillomavirus latency has been proposed in which papillomaviruses can be retained in the basal epithelial stem cell pool as latent infections and periodically induced to reactivate when the stem cell divides and one daughter cell is committed to terminal differentiation and induction of the viral life cycle. Tissue resident memory T-cells are hypothesized to control these periodic reactivation episodes and thus limit their duration. In this paper, evidence from human studies consistent with this model of papillomavirus latency is reviewed. Given the strong circumstantial evidence supporting a natural history of HPV infection which includes a immunologically controlled latent state, the longer term implications of HPV latency on a highly infected and aging population may warrant a more serious evaluation.
Fulltext The known unknowns of HPV natural history

Gravitt PE

J Clin Invest, 2011 Dec;121(12):4593-9.
PMID: 22133884 DOI: 10.1172/JCI57149

The discovery that certain high-risk strains of human papillomavirus (HR-HPV) cause nearly 100% of invasive cervical cancer has spurred a revolution in cervical cancer prevention by promoting the development of viral vaccines. Although the efficacy of these vaccines has already been demonstrated, a complete understanding of viral latency and natural immunity is lacking, and solving these mysteries could help guide policies of cervical cancer screening and vaccine use. Here, we examine the epidemiological and biological understanding of the natural history of HPV infection, with an eye toward using these studies to guide the implementation of cervical cancer prevention strategies.
Fulltext Characterizing the temporal dynamics of human papillomavirus DNA detectability using short-interval sampling

Liu SH, Cummings DA, Zenilman JM, Gravitt PE, Brotman RM

Cancer Epidemiol Biomarkers Prev, 2014 Jan;23(1):200-8.
PMID: 24130223 DOI: 10.1158/1055-9965.EPI-13-0666

Variable detection of human papillomavirus (HPV) DNA can result in misclassification of infection status, but the extent of misclassification has not been quantitatively evaluated.
Fulltext Comparison of Hybribio GenoArray and Roche human papillomavirus (HPV) linear array for HPV genotyping in anal swab samples

Low HC, Silver MI, Brown BJ, Leng CY, Blas MM, Gravitt PE, et al.

J Clin Microbiol, 2015 Feb;53(2):550-6.
PMID: 25502520 DOI: 10.1128/JCM.02274-14

Human papillomavirus (HPV) is causally associated with anal cancer, as HPV DNA is detected in up to 90% of anal intraepithelial neoplasias and anal cancers. With the gradual increase of anal cancer rates, there is a growing need to establish reliable and clinically relevant methods to detect anal cancer precursors. In resource-limited settings, HPV DNA detection is a potentially relevant tool for anal cancer screening. Here, we evaluated the performance of the Hybribio GenoArray (GA) for genotyping HPV in anal samples, against the reference standard Roche Linear Array (LA). Anal swab samples were obtained from sexually active men who have sex with men. Following DNA extraction, each sample was genotyped using GA and LA. The overall interassay agreement, type-specific, and single and multiple genotype agreements were evaluated by kappa statistics and McNemar's χ(2) tests. Using GA and LA, 68% and 76% of samples were HPV DNA positive, respectively. There was substantial interassay agreements for the detection of all HPV genotypes (κ = 0.70, 86% agreement). Although LA was able to detect more genotypes per sample, the interassay agreement was acceptable (κ = 0.53, 63% agreement). GA had poorer specific detection of HPV genotypes 35, 42, and 51 (κ < 0.60). In conclusion, GA and LA showed good interassay agreement for the detection of most HPV genotypes in anal samples. However, the detection of HPV DNA in up to 76% of anal samples warrants further evaluation of its clinical significance.
Fulltext High-risk human papillomavirus viral load and persistence among heterosexual HIV-negative and HIV-positive men

Grabowski MK, Gray RH, Serwadda D, Kigozi G, Gravitt PE, Nalugoda F, et al.

Sex Transm Infect, 2014 Jun;90(4):337-43.
PMID: 24482488 DOI: 10.1136/sextrans-2013-051230

OBJECTIVES: High-risk human papillomavirus (HR-HPV) viral load is associated with HR-HPV transmission and HR-HPV persistence in women. It is unknown whether HR-HPV viral load is associated with persistence in HIV-negative or HIV-positive men.
METHODS: HR-HPV viral load and persistence were evaluated among 703 HIV-negative and 233 HIV-positive heterosexual men who participated in a male circumcision trial in Rakai, Uganda. Penile swabs were tested at baseline and 6, 12 and 24 months for HR-HPV using the Roche HPV Linear Array, which provides a semiquantitative measure of HPV shedding by hybridisation band intensity (graded: 1-4). Prevalence risk ratios (PRR) were used to estimate the association between HR-HPV viral load and persistent detection of HR-HPV.
RESULTS: HR-HPV genotypes with high viral load (grade:3-4) at baseline were more likely to persist than HR-HPV genotypes with low viral load (grade: 1-2) among HIV-negative men (month 6: adjPRR=1.83, 95% CI 1.32 to 2.52; month 12: adjPRR=2.01, 95% CI 1.42 to 3.11), and HIV-positive men (month 6: adjPRR=1.33, 95% CI 1.06 to 1.67; month 12: adjPRR=1.73, 95% CI 1.18 to 2.54). Long-term persistence of HR-HPV was more frequent among HIV-positive men compared with HIV-negative men (month 24: adjPRR=2.27, 95% CI 1.47 to 3.51). Persistence of newly detected HR-HPV at the 6-month and 12-month visits with high viral load were also more likely to persist to 24 months than HR-HPV with low viral load among HIV-negative men (adjPRR=1.67, 95% CI 0.88 to 3.16).
CONCLUSIONS: HR-HPV genotypes with high viral load are more likely to persist among HIV-negative and HIV-positive men, though persistence was more common among HIV-positive men overall. The results may explain the association between high HR-HPV viral load and HR-HPV transmission.
Achieving equity in cervical cancer screening in low- and middle-income countries (LMICs): Strengthening health systems using a systems thinking approach

Gravitt PE, Silver MI, Hussey HM, Arrossi S, Huchko M, Jeronimo J, et al.

Prev Med, 2021 03;144:106322.
PMID: 33678230 DOI: 10.1016/j.ypmed.2020.106322

The World Health Organization (WHO) is leading a call to action to eliminate cervical cancer by the end of the century through global implementation of two effective evidence-based preventive interventions: HPV vaccination and cervical screening and management (CSM). Models estimate that without intervention, over the next 50 years 12.2 million new cases of cervical cancer will occur, nearly 60% of which are preventable only through CSM. Given that more than 80% of the cervical cancer occurs in low- and middle-income countries (LMICs), scaling up sustainable CSM programs in these countries is a top priority for achieving the global elimination goals. Multiple technologies have been developed and validated to meet this need. Now it is critical to identify strategies to implement these technologies into complex, adaptive health care delivery systems. As part of the coordinated cervical cancer elimination effort, we applied a systems thinking lens to reflect on our experiences with implementation of HPV-based CSM programs using the WHO health systems framework. While many common health system barriers were identified, the effectiveness of implementation strategies to address them was context dependent; often reflecting differences in stakeholder's belief in the quality of the evidence supporting a CSM algorithm, the appropriateness of the evidence and algorithm to context, and the 'implementability' of the algorithm under realistic assessments of resource availability and constraints. A structured planning process, with early and broad stakeholder engagement, will ensure that shared-decisions in CSM implementation are appropriately aligned with the culture, values, and resource realities of the setting.
Fulltext Secondary Prevention of Cervical Cancer: ASCO Resource-Stratified Guideline Update

Shastri SS, Temin S, Almonte M, Basu P, Campos NG, Gravitt PE, et al.

JCO Glob Oncol, 2022 Sep;8:e2200217.
PMID: 36162041 DOI: 10.1200/GO.22.00217

PURPOSE: To update resource-stratified, evidence-based recommendations on secondary prevention of cervical cancer globally.
METHODS: American Society of Clinical Oncology convened a multidisciplinary, multinational Expert Panel to produce recommendations reflecting four resource-tiered settings. A review of existing guidelines, formal consensus-based process, and modified ADAPTE process to adapt existing guidelines was conducted. Other experts participated in formal consensus.
RESULTS: This guideline update reflects changes in evidence since the previous update. Five existing guidelines were identified and reviewed, and adapted recommendations form the evidence base. Cost-effectiveness analyses provided indirect evidence to inform consensus, which resulted in ≥ 75% agreement.
RECOMMENDATIONS: Human papillomavirus (HPV) DNA testing is recommended in all resource settings; visual inspection with acetic acid may be used in basic settings. Recommended age ranges and frequencies vary by the following setting: maximal: age 25-65 years, every 5 years; enhanced: age 30-65 years, if two consecutive negative tests at 5-year intervals, then every 10 years; limited: age 30-49 years, every 10 years; basic: age 30-49 years, one to three times per lifetime. For basic settings, visual assessment is used to determine treatment eligibility; in other settings, genotyping with cytology or cytology alone is used to determine treatment. For basic settings, treatment is recommended if abnormal triage results are obtained; in other settings, abnormal triage results followed by colposcopy is recommended. For basic settings, treatment options are thermal ablation or loop electrosurgical excision procedure; for other settings, loop electrosurgical excision procedure or ablation is recommended; with a 12-month follow-up in all settings. Women who are HIV-positive should be screened with HPV testing after diagnosis, twice as many times per lifetime as the general population. Screening is recommended at 6 weeks postpartum in basic settings; in other settings, screening is recommended at 6 months. In basic settings without mass screening, infrastructure for HPV testing, diagnosis, and treatment should be developed.Additional information is available at www.asco.org/resource-stratified-guidelines.