Auckland City Hospital, Auckland, New Zealand. Electronic address: firstname.lastname@example.org.
BACKGROUND & AIMS:
There is a close relationship between chronic hepatitis B virus infection and chronic renal disease. We analyzed changes in renal function using different markers of glomerular filtration rate (GFR) in multiple studies of telbivudine treatment of patients with chronic hepatitis B virus infection.
We used serum creatinine-based equations (ie, Cockcroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration) to estimate GFR (eGFR) in adults with chronic hepatitis B virus infection and compensated liver disease who participated in a phase III, randomized, double-blind study comparing the efficacy and safety of telbivudine (600 mg/d) and lamivudine (100 mg/d) for 2 years (the GLOBE study) and in long-term extension studies (4-6 years), as well as in patients with decompensated cirrhosis (2 years).
eGFRs calculated using the Cockcroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration equations were concordant, indicating improved renal function in telbivudine-treated patients during the 2-year GLOBE study (there was an 8.5% increase in mean eGFR, based on the Modification of Diet in Renal Disease equation). Improved renal function was maintained for 4-6 years. Increased eGFR with telbivudine treatment was also observed in patients at increased risk for renal impairment: patients with baseline eGFRs of 60-89 mL/min/1.73 m2 (+17.2%), older than 50 years (+11.4%), and with liver fibrosis/cirrhosis (+7.2% for patients with Ishak fibrosis score at 5-6). In decompensated patients with high renal risk, eGFR was also improved on telbivudine (+2.0%).
In global trials of patients with compensated and decompensated cirrhosis, long-term telbivudine therapy was associated with a sustained improvement of renal function-particularly among patients with increased risk of renal impairment. The mechanisms of this renal protective effect remain to be determined.