Switching to abacavir versus use of a nucleoside-sparing dual regimen for HIV-infected patients with tenofovir-associated renal toxicity

ObjectivesWe investigated the reversibility of tenofovir disoproxil fumarate (TDF)-associated renal decline and tubular dysfunction using different antiretroviral strategies. MethodsA successive evaluation of renal [estimated glomerular filtration rate (eGFR)] and tubular (phosphataemia, proteinuria, albuminuria, phosphaturia, uricosuria, glycosuria and tubular proteinuria) parameters was performed in 231 patients, before and after switching from TDF to abacavir (n = 60), using dual therapy (n = 49), or continuing the same regimen including TDF (n = 122). ResultsIn a successive evaluation after a median of 8.86 months, or less time if treatment was switched (4.8 months vs. 13.3 months to second evaluation; P < 0.01), a significant improvement in eGFR (median change +0.3 vs. -2.91 mL/min/1.73 m(2) in patients who did not discontinue TDF; P = 0.04) and tubular dysfunction (median change -40% vs. +30%, respectively; P < 0.01) was observed. Lineal regression showed that age ( = -0.14; P = 0.04), previous eGFR decline ( = -0.42; P < 0.01), and time on TDF ( = -0.19; P = 0.04) were associated with impaired eGFR recovery. There were no differences in eGFR slopes between patients using abacavir instead of TDF and those using a dual therapy, who showed similar improvement in proteinuria (-22% vs. -19%, respectively), phosphaturia (+10.1% vs. +9.4%, respectively), and urinary beta-2-microglobulin (-9% vs. -15%, respectively; P > 0.1 for all), although patients receiving the dual regimen were more heavily pretreated. A eGFR decrease (-6.17 mL/min/1.73 m(2)) was observed in patients taking dolutegravir or rilpivirine, but with similar improvement to that observed in the rest of switching patients in tubular abnormalities. ConclusionsTenofovir disoproxil fumarate discontinuation was associated with a rapid and significant improvement in eGFR and tubular abnormalities, regardless of whether abacavir or dual therapy was chosen. Switching to a regimen that included dolutegravir and/or rilpivirine was associated with a eGFR decrease without differences in the rate of tubular dysfunction improvement in comparison with the rest of patients who discontinued tenofovir.