Microvesicles (MVs) are extracellular vesicles released by cells following activation or apoptosis. Some MV subpopulations augment with cirrhosis severity and contribute to portal hypertension. This study aimed at determining if plasma MV levels can estimate the presence of hepatic venous pressure gradient (HVPG) ≥10 mm Hg and predict mortality in patients with advanced chronic liver disease. All patients with severe fibrosis or cirrhosis undergoing liver catheterization between 2013 and 2015 at two centers were prospectively included. We measured circulating levels of annexin V+, platelet, leukocyte, endothelial, and hepatocyte MVs. The test cohort included 139 patients. Hepatocyte MV levels were 4.0-fold and 2.2-fold higher in patients with Child-Pugh C than in those with Child-Pugh A or B liver disease, respectively. Levels of other MV subpopulations were not influenced by liver disease severity. Hepatocyte MV levels correlated with HVPG but could not identify patients with HVPG ≥10 mm Hg. Hepatocyte MV level >65 U/L predicted 6-month mortality independently of Child-Pugh score and of Model for End-Stage Liver Disease (MELD). Patients with hepatocyte MV levels >65 U/L and MELD >15 had a higher 6-month mortality than other patients (23% versus 3%; P = 0.001). These findings were confirmed in a validation cohort including 103 patients.
Circulating MV levels cannot identify patients with HVPG ≥10 mm Hg; by contrast, hepatocyte MV levels strongly improve prediction of 6-month mortality in patients with advanced chronic liver disease; therapies associated with decreased levels of circulating hepatocyte MV might be attractive strategies in patients with severe cirrhosis. (Hepatology 2018).