Renal safety of tenofovir in HIV-infected children : a prospective, 96-week longitudinal study

Background: The renal safety of tenofovir in HIV-infected children has not been well studied. In paediatrics, prediction of glomerular filtration rate (GFR) is usually obtained by the Schwartz equation; the Cockcroft-Gault equation is considered more appropriate in children aged >12 years, but can be misleading in younger children. The aims of this study were to assess renal safety and GFR changes as estimated by the Schwartz and Cockcroft-Gault equations in HIV-infected children treated with tenofovir for 96 weeks. Methods: Several parameters of glomerular and tubular function were prospectively assessed (at baseline and at weeks 24, 48, 72 and 96) in 27 HIV-infected children (aged 4.9-18.0 years) receiving a tenofovir-containing antiretroviral regimen. GFR was estimated using Schwartz and Cockcroft-Gault equations in children younger and older than 12 years, respectively. Results: No child experienced a grade 1 (> or =44 micromol/L) or higher increase in serum creatinine or a grade 1 (< or =0.71 mmol/L) or higher hypophosphataemia. Serum bicarbonate values were in the normal range for age at baseline. Mean serum creatinine, serum phosphorus and serum bicarbonate values remained unchanged. No child showed proteinuria, microalbuminuria or glycosuria at baseline or during the study period. The mean urinary protein/creatinine, albumin/creatinine, alpha(1)-microglobulin/creatinine and maximal tubular phosphate reabsorption (TmPO(4)/GFR) ratios remained unchanged. Up to week 96, no patient experienced a significant decrease in GFR, as estimated by the more appropriate formula for age. Conclusion: Through 96 weeks, we found no evidence of impaired glomerular or tubular renal function in tenofovir-treated HIV-infected children.