Diagnostic performance of Mac‐2 binding protein glycosylation isomer (M2BPGi) in screening liver fibrosis in health checkups

BACKGROUND: Mild‐to‐moderate fibrosis is rarely diagnosed because the disease is asymptomatic in the early stage. The serum level of Mac‐2 binding protein glycosylation isomer (M2BPGi) has been found to increase with the severity of liver fibrosis. The aim of this study was to determine the diagnostic performance of M2BPGi in screening liver fibrosis using magnetic resonance elastography (MRE) as a reference standard and to compare it with using the aspartate aminotransferase‐to‐platelet ratio (APRI) and the Fibrosis‐4 index (FIB‐4) in health checkups. METHODS: This cross‐sectional study consecutively selected subjects at health examinations who underwent MRE and M2BPGi testing at eight health promotion centers in Korea between January and September 2019. The serum M2BPGi level was measured using the chemiluminescence enzyme immunoassay method. The measured levels were indexed using the cutoff index (COI). COI values of M2BPGi were compared with the MRE results. RESULTS: The median (interquartile) values of COI for fibrosis stages F0 (normal liver stiffness), F1 (mild fibrosis), F2 (significant fibrosis), and ≥F3 (advanced fibrosis) were 0.49 (0.34‐0.61), 0.48 (0.38‐0.68), 0.64 (0.43‐1.03), and 1.01 (0.75‐1.77), respectively (P < .0001). The AUCs of the COI for the screening of fibrosis stage ≥F1, ≥F2, and ≥F3 were 0.591, 0.698, and 0.853, respectively. Using a threshold of 0.75 for COI to exclude advanced fibrosis had a sensitivity, specificity, and negative predictive value of 80.0%, 77.9%, and 98.9%, respectively. The AUC for excluding advanced fibrosis was better for M2BPGi than for FIB‐4 and APRI. CONCLUSION: Serum M2BPGi was useful for screening significant and advanced fibrosis in health checkups.