Introduction: Evidence regarding long-term evolution of renal function in patients with human immu­nodeficiency virus (HIV) infection treated with tenofovir disoproxil fumarate (TDF) is scarce and often retrospective.
Material and methods: We carried out an observational prospective cohort study. Patients with serum creatinine lower than 1.2 mg/dl and an estimated glomerular filtration rate (eGFR) higher than 60 ml/min/1.73 m2 were included between January 2001 and December 2005. The primary outcome was the onset of a clinically relevant decrease in renal function (CRDRF) defined as an eGFR < 60 ml/min/1.73m2 in two consecutive measures or < 50 ml/min/1.73 m2 in any measure. Secondary objectives were to identify risk factors for the emergence of CRDRF and renal recovery after TDF discontinuation.
Results: Seventy patients receiving TDF and 58 controls were included. After a median follow-up of 7.6 years, 10 patients in the TDF group and none in the control group developed CRDRF (p = 0.005). The incidence rate of CRDRF was 2.2 cases per 100 treated patients per year (CI 95%: 0.85-3.62). Risk factors for CRDRF onset were higher baseline age (HR = 1.1, CI 95%: 1.05-1.18; p = 0.001), arterial hypertension (HR = 24.8, CI 95%: 3.3-185.6; p = 0.002) and lower baseline eGFR (HR = 0.93, CI 95%: 0.89-0.97; p = 0.002). After 36 months from TDF discontinuation in CRDRF cases, seven patients achieved renal recovery (eGFR > 60 ml/min/1.73 m2 in ≥ 2 consecutive measures, with six months between each measure).
Conclusions: Long-term use of TDF in the treatment of HIV infection is associated with a higher incidence of a clinically relevant decrease in renal function which may be only partially reversible.