Mac-2 binding protein glycosylation isomer is a potential biomarker to predict portal hypertension and bacterial infection in cirrhotic patients

Objectives: Mac-2-binding protein glycosylation isomer (M2BPGi) is a novel plasma biomarker for liver fibrosis, but less is known about its role in portal hypertension. We aimed to evaluate the association between M2BPGi and hepatic venous pressure gradient (HVPG) and to investigate its predictive value on prognosis of cirrhotic patients. Methods: Forty-eight cirrhotic patients who underwent HVPG measurement in Taipei Veterans General hospital were retrospectively enrolled. The Spearman’s correlation test was used to analyze the correlation between plasma M2BPGi levels and HVPG and other parameters. Cox proportional hazards regression models were used to identify predictors for clinical outcomes. Results: Plasma M2BPGi levels were higher in cirrhotic patients than healthy subjects and significantly correlated with HVPG levels (rs = 0.45, p = 0.001). On multivariate Cox regression analysis, higher plasma M2BPGi levels [≥ 6 cut-off index (C.O.I)] did not predict mortality within five years for cirrhotic patients and the result was similar in patients without hepatocellular carcinoma. Interestingly, M2BPGi ≥ 6 C.O.I was a potential predictor of bacterial infection within five years [Hazar ratio (HR) = 4.51, p = 0.003]. However, M2BPGi failed to predict occurrence of other cirrhosis-related complications, including variceal bleeding, ascites formation, spontaneous bacterial peritonitis, hepatorenal syndrome and hepatic encephalopathy. Conclusion: Plasma M2BPGi levels positively correlated with HVPG and higher serum M2BPGi levels might have a potential role in predicting development of bacterial infection for cirrhotic patients with portal hypertension.