Long-term renal safety of tenofovir disoproxil in vertically HIV-infected children, adolescents and young adults: a 60-months follow-up study

Background and Objective: Sporadic cases of renal toxicity have been reported in HIV-infected children treated with tenofovir disoproxil fumarate (TDF). We assessed the long-term renal safety of TDF in a cohort of vertically HIV-infected children, adolescents and young adults. Methods: We evaluated 26 HIV-infected children, adolescents and young adults, aged 4.9-17.4 years at baseline, every 6 months for 60 consecutive months. At the baseline visit, they had an undetectable viral load and a good immune reconstitution and were being treated with lamivudine, stavudine and a protease inhibitor (PI). At the same visit, stavudine was replaced with TDF and the PI with efavirenz. Serum creatinine, estimated glomerular filtration rate (GFR), urine protein to creatinine ratio, serum phosphate, ratio of the maximum rate of tubular phosphate reabsorption to the GFR (TmPO(4)/GFR), urine glucose, and urine alpha(1)-microglobulin to creatinine ratio were used as markers of renal function. The outcome-time relationships were studied using generalized estimating equations (GEEs). In addition to time (continuous, ten equally spaced intervals), sex, age at baseline and CD4+ T-cell count were used as covariates. Results: A moderate reduction in GFR was observed only once in an underweight female patient. There was no occurrence of proteinuria, hypophosphataemia or glycosuria. Moreover, TmPO(4)/GFR was stable and the urine alpha(1)-microglobulin to creatinine ratio was always within normal limits. Conclusion: TDF had an excellent renal safety profile in HIV-infected children, adolescents and young adults regularly followed up for 60 months.