Serum Wisteria floribunda agglutinin‐positive Mac‐2 binding protein more reliably distinguishes liver fibrosis stages in non‐alcoholic fatty liver disease than serum Mac‐2 binding protein

Aim Serum Mac‐2 binding protein (M2BP) and Wisteria floribunda agglutinin‐positive Mac‐2 binding protein ( WFA + ‐M2BP) are used to estimate the liver fibrosis stage in chronic liver diseases. However, few head‐to‐head studies have been carried out to compare the two biomarkers in non‐alcoholic fatty liver disease (NAFLD). Methods Serum M2BP and WFA + ‐M2BP levels were compared against clinical characteristics and liver histological manifestations in the same samples collected from 213 biopsy‐proven NAFLD patients. Results Median levels (range) of M2BP and WFA + ‐M2BP were 1.58 (0.70–7.75) pg/mL and 0.85 (0.22–11.32) cut‐off index (COI), respectively. Fibrosis stages 1, 2, 3, and 4 were determined in 136, 37, 17, and 23 patients, respectively. Median levels of both biomarkers increased stepwise with fibrosis progression. The M2BP and WFA + ‐M2BP levels showed a significant positive correlation (r = 0.643, P = 2.91 × 10 −26 ), but a marked discrepancy between both biomarkers was noted in five stage 4 and three stage 1 patients, who had high WFA + ‐M2BP but relatively low M2BP levels. Most of these outliers had findings suggestive of more advanced fibrosis. For diagnosing any fibrosis severity, WFA + ‐M2BP had greater area under the receiver operating characteristic curve (AUC) and predictive accuracy than M2BP. Among eight fibrosis markers/indices, WFA + ‐M2BP yielded the second highest AUC (0.832) and the highest predictive accuracy (82.2%) to diagnose cirrhosis. In addition, WFA + ‐M2BP showed the second highest predictive accuracy to diagnose severe fibrosis (78.4%) and significant fibrosis (76.1%). Conclusion This head‐to‐head comparison suggests that WFA + ‐M2BP is superior to M2BP for distinguishing liver fibrosis stages in NAFLD patients. A marked discrepancy between the two biomarkers may be indicative of advanced NAFLD (UMIN000023286).