Microparticles in Cirrhosis and Portal Hypertension

It has already been shown that increased certain markers of stress, such as prolonged elevation of CRP in the absence of bacterial infection, increased free cortisol and serum copeptin, are associated with an excess of mortality in cirrhosis. MPs are membrane vesicles of variable size between 0.1 and 1 .mu.m, released into the extracellular space following activation or cellular apoptosis. MPs are also found in the circulating blood of healthy volunteers and their plasma levels rise in certain diseases to increased thrombotic risk, such as in cancer. Their membrane is composed of antigens whose organization is characteristic of the parent cell and negatively charged phospholipids, phosphatidylserines, conferring pro-coagulant properties to these MPs. Currently, work on the MPs are increasing following the discovery of their involvement in physiological processes such as proliferation, differentiation, cell activation and immune response but it is certainly their pro-thrombogenic power that was the most studied. Recent studies have also implicated MPs in the pathophysiology of chronic liver disease. Cirrhotic patients have elevated concentrations of MPs from leukocytes, endothelial cells and hepatocytes compared to control subjects, and concentrations of MPs increase with worsening liver function. Increasing MPs during the cirrhosis may be related on the one hand with a decreased clearance and secondly with an excess of proinflammatory cytokines by increasing the phenomenon of intestinal bacterial translocation. The assumption of the role of systemic inflammation in the training of MPs is reinforced by the existence of a significant correlation between the original MPs hepatocyte or buffy endothelial and CRP Thus, the increase in MPs observed with the increase of PH could increase the risk of thrombosis in intestinal microcirculation leading to enterocytic suffering from ischemic, reflected by an increase in serum concentrations of I-FABP ( intestinal fatty acid binding protein). This suffering enterocytes leads to increased intestinal bacterial translocation and ultimately to increased formation of MPs. These MPs could also worsen liver function by the same phenomenon of thrombosis in the hepatic microcirculation.