Effects of entecavir and tenofovir alafenamide fumarate treatment on renal function in Japanese elderly patients with chronic hepatitis B

Aim: Entecavir (ETV) and tenofovir alafenamide fumarate (TAF) are considered safe nucleoside/nucleotide analogs (NA) for the kidney. This study aimed to investigate the long-term effects of ETV or TAF on renal function in elderly patients with chronic hepatitis B (CHB) in Japan.Methods: The study included 246 CHB patients treated with ETV (184 patients) or TAF (62 patients) for at least 2 years. These patients were divided into two groups: those <65 years of age (130 patients) and those >65 years of age (116 patients). The effects of the NAs on renal functions were examined by comparing the estimated glomerular filtration rates (eGFR) from baseline to 2 years between the two groups.Results: The change in eGFR from baseline to 1 or 2 years after treatment was significantly decreased in both groups. However, the amount of change at 1 and 2 years was significantly greater in the group aged >= 65 years than in the group aged <65 years. The amount of change in eGFR from baseline to 1 and 2 years after treatment was significantly greater in the group aged >= 65 years than in the group aged <65 years, regardless of the type of NA, the prior treatment history, cirrhosis/ chronic hepatitis, hypertension, dyslipidemia, and diabetes. Additionally, logistic regression analysis showed that age >= 65 years was independently associated with a decreased eGFR after 2 years of NA treatment.Conclusions: Long-term administration of NA to CHB patients over 65 years of age should be carefully monitored for renal impairment.