Evaluation of alanine aminotransferase responses in chronic hepatitis B patients using entecavir or tenofovir disoproxil fumarate

Abstract

Background/Aim: An estimated 300 million individuals worldwide live with hepatitis B virus (HBV) infection. Alanine aminotransferase (ALT) levels, which indicate liver damage when elevated, are among the crucial laboratory parameters frequently monitored in the follow-up of chronic hepatitis B patients. The primary objectives of antiviral treatment are to reduce liver inflammation and prevent the development of hepatocellular carcinoma or cirrhosis by inhibiting HBV replication. This study evaluated ALT responses and identified factors influencing patient responses following initiating entecavir (ETV) or tenofovir disoproxil fumarate (TDF) treatment. Methods: This retrospective cohort study collected data from treatment-naive and treatment-experienced patients with elevated ALT levels who received either ETV (0.5 or 1 mg per day) or TDF (245 mg per day) treatment between 2008 and 2018. Pregnant women and patients under 18 were excluded from the study. Elevated ALT levels were defined as greater than 35 IU/L for men and 25 IU/L for women. All patients underwent examinations for ALT, HBV DNA levels, HBeAg, and antiHBe at baseline and every 3–6 months. ALT levels of the patients were monitored for 60 months, and the presence of fatty liver was also documented. Results: Our study comprised 192 patients with a mean age of 53.7 (13.42) years. The majority of patients, 130 (67.7%), were male. Of these, 97 (50.5%) started ETV treatment, while 95 (49.5%) began TDF treatment. The median baseline ALT levels of the patients were 68 (44–133.5) IU/L, and the median ALT levels at the 60th month were 24 (18–32) IU/L. The median initial HBV DNA level was 114,282 (267.5–5,029,875) IU/mL, and the median HBV DNA levels from the 6th month onwards were 0 (0–0). ALT normalization was observed in 44.8% of men and 28.1% of women at 3 months, which was statistically significant (P=0.034). Normalization rates by gender remained consistent in all other months. No significant differences were noted in this regard. ALT normalization rates were 58.5% at the 6th month and 74.7% at the 24th month in the ETV group, significantly higher than in the TDF group (P=0.01, P=0.02, respectively). In patients with fatty liver, ALT normalization rates were significantly lower at 6, 12, 24, and 48 months than those without fatty liver (P=0.01, P=0.01, P=0.009, P=0.002, respectively). Conclusion: Although ALT responses to ETV treatment were more pronounced in specific months, both drugs demonstrated overall efficacy. ALT levels in patients with fatty liver remained elevated despite antiviral treatment. Therefore, patients with chronic hepatitis B and fatty liver may require additional support beyond antiviral therapy, including metabolic, nutritional, and lifestyle recommendations.