Histological features of chronic hepatitis B patients with normal alanine aminotransferase according to different criteria

Abstract

Background: The upper limits of normal (ULNs) for alanine aminotransferase (ALT) are different among international guidelines for chronic hepatitis B (CHB). We aimed to investigate the proportion of significant histological disease in Asian patients with CHB with detectable hepatitis B virus (HBV) DNA under diverse ALT ULNs. Methods: Consecutive patients with CHB and detectable HBV DNA who underwent liver biopsy were retrospectively included from four tertiary hospitals. Above grade 2 inflammation and stage 2 fibrosis were defined as significant inflammation and significant fibrosis, respectively. Significant histological disease was defined as above grade 2 inflammation or stage 2 fibrosis. Results: Among the 414 patients with detectable HBV DNA and normal ALT, the proportion of those with significant histological disease was lower (59.7%) according to the ULN for ALT at 30/19 U/L (male/female), while the corresponding proportions were 66.7% and 62.3% according to the ULNs of 40 U/L and 35/25 U/L (male/female), respectively. In patients with detectable HBV DNA and normal ALT levels without significant fibrosis, the proportions of significant inflammation were comparable among different ULNs of ALT at 40 U/L (30.7%), 35/25 U/L (27.3%) and 30/19 U/L (25.0%). The proportion of significant histological disease was significantly lower in patients with normal ALT for 2 determinations at least 6 months apart compared to patients with normal ALT once. Conclusions: Although a more stringent ALT ULN may reduce the risk of the presence of significant histological disease in patients with detectable HBV DNA, the rates of significant histological disease remain high. Persistently normal ALT levels are more important for excluding patients with CHB with a high probability of significant histological disease.