Changes in Renal Function in Patients With Chronic HBV Infection Treated With Tenofovir Disoproxil Fumarate vs Entecavir.

BACKGROUND & AIMS: It is unclear whether drugs used to treat chronic hepatitis B virus (HBV) infection cause significant renal impairment. We compare adjusted mean estimated glomerular filtration rates (eGFR; mL/min/1.73 m2 ) of patients with chronic HBV infection treated with tenofovir disoproxil fumarate (TDF) vs patients treated with entecavir.

METHODS: We performed a retrospective study of patients with chronic HBV infections treated with TDF (n = 239) or entecavir (n = 171), from 2000 through 2016, followed for a mean time of 43-46 months. Levels of serum creatinine were measured ≥12 months while patients received treatment. Patients did not have prior exposure to adefovir or HCV, HDV, or HIV co-infection. We performed propensity score matching (PSM) for age, sex, presence of hypertension, diabetes mellitus, baseline eGFR, cirrhosis, and follow-up duration. We performed multivariate generalized linear modeling, adjusting for cirrhosis, diabetes, and hypertension, to estimate adjusted mean eGFR for matched and unmatched cohorts. Cox regression was used to identify predictors of renal impairment.

RESULTS: eGFRs were ≥60, after PSM, in 116 patients given entecavir and in 116 patients given TDF; eGFRs were <60 in 32 patients given entecavir and 26 patients given TDF. Multivariate generalized linear modeling of the unmatched overall and <60 eGFR cohorts revealed significantly lower adjusted mean eGFRs in patients given TDF (all P < .001). However, in the eGFR ≥60 PSM cohort, the adjusted mean eGFR was similar between patients receiving either treatment. In Cox regression analysis, TDF was not associated with mild or moderate renal impairment compared with entecavir.

CONCLUSION: In a retrospective study of patients with chronic HBV infections treated with TDF vs entecavir, we found that TDF was not associated with higher risk of worsening renal function during short- or intermediate-term follow-up periods, among patients without significant renal impairment. Additional studies, with longer follow-up periods, are needed because treatment for chronic HBV infection is generally long term or life-long. For patients with baseline renal impairment, significant renal decline was among patients given TDF compared to patients given entecavir.