Prevalence and Serological Predictors of Liver Fibrosis in Vietnamese Chronic Hepatitis B Patients with Persistently Normal or Mildly Elevated Aminotransferase Level.

Background: Chronic hepatitis B (CHB) remains a significant health concern, especially in low- and middle-income countries. Some CHB patients with normal or mildly elevated ALT may have advanced liver fibrosis, which often goes undetected. Objective: The aim of this study was to assess the prevalence of significant fibrosis and the diagnostic accuracy of serum markers in CHB patients with ALT <2× ULN in Vietnam. Methods: A cross-sectional study was conducted at 175 Military Hospital between October 2019 and December 2021. A total of 144 CHB patients with ALT <2× ULN were assessed for liver fibrosis using FibroScan (METAVIR criteria). The diagnostic accuracy of APRI and FIB-4 was evaluated using receiver operating characteristic (ROC) curves. Results: Among 144 participants, 26.4% exhibited advanced fibrosis (F≥2), including 9% with cirrhosis. Advanced fibrosis correlated with older age (50 vs. 42 years, p=0.012), male sex (p=0.024), higher AST, ALT, and GGT levels (p<0.05), and lower platelet counts (PLT) (p<0.001). APRI and PLT demonstrated the highest diagnostic accuracy (AUC=0.802 and 0.805, respectively). APRI achieved 84.2% sensitivity and 92.5%, negative predictive value (NPV), while PLT had the highest specificity (81.1%). FIB-4 (AUC=0.716), ALT (AUC=0.676), and prothrombin time (PT) (AUC=0.646), had moderate performance. Combining APRI and PLT significantly improved diagnostic accuracy (p<0.05). Conclusion: Significant fibrosis was present in 26.4% of CHB patients with normal or mildly elevated ALT levels. APRI and PLT are reliable and cost-effective to detect early fibrosis in re-source-limited settings. These findings underscore the need to revise Vietnam's CHB management strategies for earlier fibrosis diagnosis and treatment.