 Patients with cirrhosis of viral etiology HCVHBV; Patients with cirrhosis of any other etiology alcohol, idiopatic, autoimmune. Planned Number of cirrhotic subjects 200 patients Inclusion Criteria Subjects 18 yr old with liver cirrhosis of any etiology, Exclusion Criteria All patients should not have hepatocellular carcinoma or other malignant tumors, they should not be treated with anticoagulant antiplatelet agents, not affected by PVT already diagnosed and not suffering from congenital coagulation disorders haemophilia A B, von disease Willebrand, another congenital deficiency of coagulation factors or severe thrombocytopenia 30,000 Plt μL. Subject has participated in another clinical study within 30 days prior to study enrollment or is scheduled to participate in another clinical study on cirrhosis Primary Objective To describe the prospective modification of ADAMTS-13 level and other coagulation variables e.g. FVIII, VWF:AgVWF:act in cirrhotic patients during 18 months from the enrolment and to verify their predictive role as biomarker of development of portal vein thrombosis PVT Secondary Objectives To describe prospectively the modification of ADAMTS-13 level as a function of the etiology of cirrhosis Statistical analysis The total duration of the study will be of 12 months. The sample size of 200 subjects will be selected as a feasible number of patients to be recruited in a period of six months. The patients will be consecutively enrolled and followed for 18 months. As a result, in a follow up period of 18 months about 20-25 cases of PVT are expected. Continuous variables will be expressed as means standard deviations. In addition to descriptive statistics location parameters, univariate analysis will be performed on each parameter and development of PVT during the follow up period. In previous observational studies both 1 a reduced PV flow prospectively and 2 a reduction of ADAMTS-13 are significantly associated with PVT. These associations will be investigated prospectively and analyzed simultaneously by a multivariate analysis and ROC curve to establish the sensitivity and specificity of these parameters as predictors of PVT development. Analyses will be performed using available data 