Despite advances in therapy, HIV-infected individuals remain at higher risk for kidney dysfunction than uninfected individuals. Current measures of kidney function, such as serum creatinine and dipstick proteinuria, are late and nonspecific markers of kidney damage in HIV-infected individuals, and do not differentiate the etiology or site of injury within the nephron. Early identification of tubular dysfunction is particularly important in HIV-infected persons receiving tenofovir, an antiretroviral medication with direct toxicity to proximal tubular epithelial cells. We propose a novel paradigm for the assessment of kidney health in HIV-infected individuals, using a panel of urinary biomarkers which can detect early kidney injury, localize pathology within the nephron, and differentiate drug toxicity from alternate etiologies of kidney damage. We recently measured urine levels of interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), a1-microglobulin (a1m), and albuminuria in 886 HIV-infected and 350 uninfected men enrolled in the Multicenter AIDS Cohort Study (MACS). The current project will compare levels of each biomarker between HIV-infected and uninfected men;identify the specific risk factors associated with each biomarker among the HIV-infected participants;determine the impact of tenofovir use on kidney health based on biomarker levels;and evaluate longitudinal associations of each urine biomarker with kidney function decline over 4 years. Identification of early kidney injury in HIV-infected persons, using biomarker levels, could enable targeted interventions prior to the development of irreversible kidney damage. Additionally, these research objectives will lay foundation for future longitudinal investigations examining the utilities of biomarkers for the detection of drug toxicity, particulary among HIV-infected persons receiving nephrotoxic therapies.

Public Health Relevance

Current tests of kidney function are unable to detect early kidney damage in HIV-infected individuals. Urinary biomarkers represent a new frontier in the assessment of kidney function, with the abilities to detect and distinguish various types of injury within the kidney. Studying biomarkers in HIV-infected persons can enable clinicians to diagnose and treat kidney disease at earlier stages, and may impact the preventative care provided to millions of HIV-infected individuals.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
1F32DK103451-01
Application #
8783329
Study Section
Special Emphasis Panel (ZDK1)
Program Officer
Rankin, Tracy L
Project Start
2014-07-03
Project End
2016-07-02
Budget Start
2014-07-03
Budget End
2015-07-02
Support Year
1
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Jotwani, Vasantha; Scherzer, Rebecca; Estrella, Michelle M et al. (2016) Brief Report: Cumulative Tenofovir Disoproxil Fumarate Exposure is Associated With Biomarkers of Tubular Injury and Fibrosis in HIV-Infected Men. J Acquir Immune Defic Syndr 73:177-81
Jotwani, Vasantha; Shlipak, Michael G; Scherzer, Rebecca et al. (2015) APOL1 Genotype and Glomerular and Tubular Kidney Injury in Women With HIV. Am J Kidney Dis 65:889-98