Low-Cost Method to Monitor Patient Adherence to HIV Antiretroviral Therapy Using Multiplex Cathepsin Zymography

• Type of Material: Article
• Authors: Manu Platt, Emory University; Denise Evans, University of Witwatersrand; Philip M. Keegan, Georgia Institute of Technology; Lynne McNamara, University of Witwatersrand; Ivana K. Parker, Georgia Institute of Technology; LaDeidra M. Roberts, Georgia Institute of Technology; Alexander W. Caulk, Georgia Institute of Technology; Rudolph L. Gleason, Jr., Georgia Institute of Technology; Daniel Seifu, Addis Ababa University; Wondwossen Amogne, Addis Ababa University; Clement Penny, University of Witwatersrand
• Language: English
• Date: 2016-01-01
• Publisher: Humana Press
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2015, Springer Science+Business Media New York.
• Final Published Version (URL): http://dx.doi.org/10.1007/s12033-015-9903-0
• Title of Journal or Parent Work: Molecular Biotechnology
• ISSN: 1073-6085
• Volume: 58
• Issue: 1
• Start Page: 56
• End Page: 64
• Grant/Funding Information: This work was completed partially with funding from a Creative and Novel Ideas in HIV Research (CNIHR) grant sponsored by the National Institutes of Health and The University of Alabama at Birmingham Center for AIDS Research (CFAR) program (5P30A1027767) (MOP and DE), funding from NIH Award Number DP2OD007433 from the Office of the Director, National Institutes of Health (MOP). American Heart Association (RLG), and United States Agency for International Development (USAID) (DE).; This study is made possible by the generous support of the American people through Cooperative Agreement AID 674-A-12-00029 from the United States Agency for International Development (USAID).
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cysteine protease; Biochemistry & Molecular Biology; Infectious disease; Zymography; Sub-Saharan Africa; Monitoring; Biotechnology & Applied Microbiology; AIDS
• Research Categories: Engineering, Biomedical; Chemistry, Biochemistry

Abstract

Monitoring patient adherence to HIV antiretroviral therapy (ART) by patient survey is inherently error prone, justifying a need for objective, biological measures affordable in low-resource settings where HIV/AIDS epidemic is highest. In preliminary studies conducted in Ethiopia and South Africa, we observed loss of cysteine cathepsin activity in peripheral blood mononuclear cells of HIV-positive patients on ART. We optimized a rapid protocol for multiplex cathepsin zymography to quantify cysteine cathepsins, and prospectively enrolled 350 HIV-positive, ART-naïve adults attending the Themba Lethu Clinic, Johannesburg, South Africa, to test if suppressed cathepsin activity could be a biomarker of ART adherence (103 patients were included in final analysis). Poor adherence was defined as detectable viral load (>400 copies/ml) or simplified medication adherence questionnaire, 4–6 months after ART initiation. 86 % of patients with undetectable viral loads after 6 months were cathepsin negative, and cathepsin-positive patients were twice as likely to have detectable viral loads (RR 2.32 95 % CI 1.26–4.29). Together, this demonstrates proof of concept that multiplex cathepsin zymography may be an inexpensive, objective method to monitor patient adherence to ART. Low cost of this electrophoresis-based assay makes it a prime candidate for implementation in resource-limited settings.