Serum Mac-2 Binding Protein Glycosylation Isomer (M2BPGi) Can Predict Mild or Significant Liver Fibrosis in Non-alcoholic Fatty Liver Disease

Background: The serum levels of M2BPGi increase with liver fibrosis progression in patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. However, the diagnostic performance of M2BPGi in non-alcoholic fatty liver disease (NAFLD) patients remains unclear. Objectives: To assess the severity of liver fibrosis in NAFLD patients and healthy controls by M2BPGi using acoustic radiation force impulse (ARFI) as the standard reference. Methods: Those suffering from NAFLD and healthy controls were recruited. NAFLD diagnosis was confirmed using fatty liver in imaging after excluding HCV, HBV, alcohol, drug, or other known causes of chronic liver disease. ARFI was used as the standard reference to determine the stage of liver fibrosis. Results: A total of 226 subjects were recruited, including 130 (57.5%) NAFLD patients who were divided into three groups according to the stage of liver fibrosis: F0, F1, and F ≥ 2. The serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST to platelet ratio index (APRI), M2BPGi, and the fatty liver grade were significantly different between the three groups. The levels of M2BPGi were correlated with median ARFI value (P < 0.001), APRI (P = 0.011), and fibrosis 4 index (FIB-4) (P < 0.001). The area under the curve (AUC) of M2BPGi test was 0.58 for F ≥ 1 and 0.68 for F ≥ 2, respectively (P = 0.039 and P = 0.024). Conclusions: The M2BPGi levels were correlated with ARFI, APRI, and FIB-4 scores in this study population. The level of M2BPGi could predict mild (F ≥ 1) and significant liver fibrosis (F ≥ 2) in NAFLD patients, suggesting a surrogate marker to differentiate between normal, mild, and significant fibrosis.