Tenofovir renal safety in HIV-infected patients: results from the SCOLTA Project

OBJECTIVE: To evaluate the prevalence and incidence of nephrotoxicity in HIV-infected patients enrolled in the SCOLTA Project tenofovir cohort and to identify possible risk factors. DESIGN: The SCOLTA Project is a prospective, observational, multicenter study involving 25 infectious disease departments in Italy created to assess the incidence of severe adverse events in patients receiving new antiretroviral drugs. PATIENTS: The SCOLTA Project tenofovir cohort includes a total of 754 HIV infected patients. RESULTS: Data including grade II-IV creatinine elevations according to ACTG scale were available in 354 patients, 237 (67%) males with a mean age of 40.1+/-7.6 years enrolled in the SCOLTA Project tenofovir cohort. During a mean follow up of 19.5+/-11.5 months creatinine elevations were reported in 9/354 (2.5%) patients, all males. Mean duration of tenofovir therapy at the event was 9.5+/-5 months. The overall incidence was 1.6 (95% CI 1.5-1.7) per 100 person-years (p-y) and 0.5 (95% CI 0.4-0.6) p-y for grade III. No grade IV creatinine elevations were reported. Patients with nephrotoxicity were older and more frequently male, HCV infected, in CDC stage C and their CD4 cell count was significantly lower than those without nephrotoxicity. No significant difference was found between tenofovir co-administered antiretroviral drugs. CONCLUSIONS: Both prevalence and incidence of nephrotoxicity were low in patients receiving tenofovir in a non-selected clinical setting. Renal injury in patients receiving tenofovir seems associated with the presence of co-morbidities and with advanced HIV infection.