Validation of estimated renal function measurements compared with the isotopic glomerular filtration rate in an HIV-infected cohort

We performed a cross-sectional study to determine the best method for estimating the glomerular filtration rate (GFR) in HIV-infected subjects. Isotopic GFR was correlated with 24-h urine creatinine clearance, cystatin C levels, and 3 creatinine-based equations—the Modification of Diet in Renal Disease (MDRD), Cockcroft–Gault (CG), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)—in 15 patients. Cystatin C showed the strongest correlation with isotopic GFR (r = −0.760, p = 0.001). When cystatin C was used as the reference variable for all 106 patients, CKD-EPI proved to be superior to the other equations (r = −0.671, p < 0.001). Time with HIV infection, unsuppressed viral load, low CD4 T-cell counts, and use of protease inhibitors are related to an increased risk of renal impairment, leading us to recommend early initiation of antiretroviral therapy accompanied by a regular renal study.