Prevalence of kidney injury in patients taking tenofovir based antiretroviral therapy at a primary health care clinic, in East Rand,Gauteng Province

Background: Tenofovir disoproxil fumarate (TDF) is currently one of the key medicines in the management of HIV-1 infection across the globe. Conversely, various studies indicate that TDF is associated with an increased risk of kidney injury. Furthermore, data from different studies indicate that clinically significant TDF-related kidney toxicity is uncommon, with an estimated incidence of reduction in creatinine clearance to below 50 ml/min ranging from 3% to 8%. Objective: This study investigated the prevalence of TDF-induced kidney injury, risk factors associated with the exacerbation of kidney injury, and reversibility of TDF-induced kidney injury in a South African cohort. Methods: A retrospective cross-sectional descriptive study was conducted, where quantitative data were collected through patient file reviews. Files of 600 patients initiated on TDF-based antiretroviral therapy (ART) were reviewed. The degree of kidney function was monitored using the eGFR at baseline, 3, 6, 12, and 36 months of TDF therapy. eGFR after TDF discontinuation was monitored to determine its reversibility. HIV parameters (CD4 count and viral load) were monitored to determine patients’ immune response to treatment throughout the study. Comorbidities and other factors that affect kidney function were extracted from the patients’ files. Results: Final sample comprised 413 files, 272 (65.9%) were females. Significant variability in the eGFR overtime was observed; 20 (5.9%) experienced mild-moderate kidney injury, four (1.2%) developed moderate-severe kidney injury and three (1%) had severe kidney injury. Significant association with decline in eGFR included high viral load, low CD4 count and long duration of treatment. Six (1.5%) patients were discontinued from TDF treatment and five patients of those fully recovered. Conclusions: TDF-induced kidney injury was uncommon in this setting and where it occurred was associated with full reversibility after discontinuation. Therefore, lack of resources in health-care settings in terms of frequent monitoring of renal function should not prevent prescribing TDF-based therapy.