The potential value of fatty acid binding protein 1 in Chronic HBV-related liver disease progression assessment.

Background: Fatty acid binding protein 1 (FABP1), a low molecular weight intracellular protein, has been proposed as a potential useful serum biomarker for liver injury. However, limited investigations have been conducted in chronic hepatitis B virus (HBV)-related liver disease.

Objective: To investigate the diagnostic potential of FABP1 in disease progression among patients with chronic HBV-related liver disease.

Methods: A prospective study was conducted on 293 patients with chronic HBV-related liver diseases, including chronic asymptomatic carrier (ASC), chronic hepatitis B (CHB). FABP1 was measured in serum samples collected at admission and some selected liver biopsies.

Results: Immunohistochemical analysis revealed abundant cytoplasmic expression of FABP1 in hepatocytes. A significant negative correlation was observed between FABP1 expression and inflammation grades in liver tissue (Spearman's r = -0.355, P = 0.017). However, no statistically significant correlation was found with fibrosis (P > 0.05). Serum FABP1 levels in the case group were significantly higher than in the healthy control (HC) group [median: 804.2 (687.8, 939.2) vs. 709.1 (626.2, 807.8) ng/ml, Z = -5.505, P < 0.001] and showed correlations with alanine aminotransferase (ALT), aspartate aminotransferase (AST); total bilirubin (TBIL); direct bilirubin (DBIL); albumin (ALB), etc. Its levels progressively increased with the advancement from ASC to CHB, with significant differences compared to the HC group (P < 0.001), especially in ASC patients with high HBV DNA (exceeding 10⁶ IU/ml, P = 0.019), HBeAg positive (P = 0.013) and ALT higher than 0.5 times upper limit of normal (ULN)(P = 0.035). Meanwhile, serum FABP1 in CHB patients with higher TBIL(P = 0.005) or the severe CHB were higher (P = 0.002).

Conclusion: Our study demonstrated a significant inverse correlation between FABP1 levels and the severity of inflammation grades in patients with HBV-related liver diseases. Furthermore, elevated serum FABP1 levels were observed in these patients, suggesting its potential as a biomarker for assessing HBV-related liver damage to initiate antiviral therapy. Additionally, further evaluation is required to determine its potential as a biomarker for assessing disease severity.