Impaired creatinine-based estimated glomerular filtration rate in Thai individuals switching to dolutegravir: illustrating the role of cystatin C testing to aid clinical decision making.

Introduction: Data about impact of switch to dolutegravir (DTG)-based antiretroviral therapy (ART) on estimated glomerular filtration rate (eGFR) in Asians are scarce. RV254/SEARCH010 is a prospective observational cohort in Bangkok, Thailand with ART initiation during acute HIV infection (AHI) where participants switched to DTG-based ART.

Methods: Participants started Efavirenz (EFV)-based ART during AHI (n = 214) and switched to DTG-based ART after a median of 97 weeks (IQR 61-145). GFR was estimated by serum creatinine (eGFR) every 24 weeks before and after switch. Estimated GFR by cystatin C (eGFR) was ordered at clinician's discretion for decreased eGFR after switch. Random-effect linear regression model was used to assess changes in eGFR over 96 weeks from starting ART, and from switching to DTG.

Results: At study entry, 20 participants (9.3%) had eGFR < 90 ml/min/1.73 m. During EFV-based ART, an additional 17 (8%) developed eGFR < 90 ml/min/1.73 m, nearly all transient, while mean eGFR remained stable and within normal range. At switch to DTG, 21 (9.8%) had eGFR < 90 ml/min/1.73 m but an additional 116 (54%) developed eGFR < 90 ml/min/1.73 m during follow-up with eGFR decrease being mostly persistent. Mean eGFR decreased 20.8% from 117.0 to 92.4 ml/min/1.73 m (p < 0.001). Among 20 post-switch participants with eGFR measured within 4 weeks of eGFR < 90 mL/min/1.73 m, 13 (65%) had normal kidney function by eGFR.

Conclusions: Persistent eGFR decrease to < 90 ml/min/1.73 m after switch to DTG was common in this Thai population. eGFR was helpful to identify individuals with clinically significant decrease in kidney function and obviate unnecessary ART modifications. Trial registration Clinical Trials Registry Number: ClininicalTrials.gov NCT00796146.