Mac-2 binding protein glycosylation isomer contributes to identify advanced Fontan-associated liver disease: A retrospective cohort study.

The usefulness of several noninvasive assessments for evaluating liver fibrosis has been reported in Fontan-associated liver disease (FALD). However, no studies have reported on the usefulness of Mac-2 binding protein glycosylation isomer (M2BPGi) in FALD. Here, we investigated the usefulness of M2BPGi in identifying advanced FALD. This retrospective study included patients diagnosed with FALD. Based on the clinical signs of portal hypertension, we defined advanced FALD as a varices, ascites, splenomegaly, and thrombocytopenia (VAST) score ≥ 2, and we compared the cardiac parameters, liver parameters, and serological fibrosis markers, including M2BPGi. The Mann-Whitney U and Fisher exact test were used to compare variables. Spearman rank correlation coefficients (r) were calculated to evaluate correlations. The accuracy of outcome prediction was evaluated using the area under the receiver operating characteristic curve (AUROC). A total of 43 patients with FALD were enrolled. There were 22 cases (51%) diagnosed with advanced FALD. In the serological fibrosis markers, M2BPGi levels were significantly higher in cases with advanced FALD (median 0.65 vs 0.38 cutoff index [C.O.I], P = .003), similar to the fibrosis-4 (FIB-4) index and aspartate aminotransferase (AST) to platelet ratio index (APRI). Receiver operating characteristic analysis revealed that M2BPGi demonstrated moderate ability to predict the cases with advanced FALD (AUROC, 0.767), and the cutoff value was 0.64 C.O.I. Moreover, M2BPGi demonstrated a significant correlation with AST (r = 0.321, P = .036), albumin (r = -0.562, P < .001), FIB-4 index (r = 0.492, P = .001), APRI (r = 0.399, P = .008), and cardiac parameters such as central venous pressure (r = 0.413, P = .006) and brain natriuretic peptide (r = 0.431, P = .004). Esophagogastric varices (31% vs 3%, P = .024) and ascites (69% vs 27%, P = .016) were more prevalent in the higher M2BPGi group. Furthermore, there was a significant trend in increasing M2BPGi with worsening the VAST scores (P = .021). This study suggests that M2BPGi may be useful for identifying advanced FALD.