Non-specific elevation of serum Mac-2 binding protein glycosylation isomer levels in patients with biliary disease.

The aim of the present study was to clarify the clinical significance of a novel fibrotic marker, serum Mac-2 binding protein glycosylation isomer (M2BPGi), in non-cirrhotic patients with biliary diseases. Associations between the serum levels of M2BPGi and clinical features (including background disease and laboratory data) were analyzed. A total of 78 patients with biliary disease (32 with biliary cancer and 46 with benign disease) were evaluated, and their clinical features (age, sex and biliary stricture status), serum level of M2BPGi and other serum laboratory data [aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyltranspeptidase (γ-GTP), alkaline phosphatase (ALP), total bilirubin (TB), direct bilirubin (DB), c-reactive protein (CRP), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9)] were compared. In addition, correlations between the serum level of M2BPGi and other laboratory data were also evaluated. The median serum M2BPGi was increased in cases of biliary tumor [cut-off index (COI), 1.91] compared with cases of benign disease (COI, 0.73; P<0.0001). All biliary cancer cases presented with biliary strictures, and 5 patients had liver metastases. Cases with liver metastases exhibited higher M2BPGi levels compared with cases without liver metastases (COI, 3.75 vs. 1.53; P=0.008). The level of M2BPGi was correlated with levels of AST, ALT, γ-GTP, ALP, TB, DB, CRP, CEA and CA19-9. In conclusion, the serum M2BPGi level could be non-specifically elevated, particularly in non-cirrhotic patients with biliary stricture.