Background & Aims Patients with cirrhosis have an increased tendency to develop thromboses despite the longer coagulation times of their plasma, compared with that of healthy individuals. We investigated whether plasma from cirrhotic patients has an imbalance of pro- vs anti-coagulation factors. Methods We analyzed blood samples from 134 cirrhotic patients and 131 healthy subjects (controls) for levels of pro- and anti-coagulants and for thrombin generation in the presence or absence of thrombomodulin (the main physiologic activator of the protein C anticoagulant pathway). Results The median ratio of thrombin generation (with/without thrombomodulin) was higher in patients (0.80; range, 0.51–1.06) than controls (0.66; range, 0.17–0.95), indicating that cirrhotic patients are resistant to the action of thrombomodulin. This resistance resulted in greater hypercoagulability of plasma from patients of Child–Pugh class C than of class A or B. The hypercoagulability of plasma from patients of Child–Pugh class C (0.86; range, 0.70–1.06) was slightly greater than that observed under the same conditions in patients with congenital protein C deficiency (0.76; range, 0.60–0.93). Levels of factor VIII, a potent pro-coagulant involved in thrombin generation, increased progressively with Child–Pugh score (from Child–Pugh class A to C). Levels of protein C, one of the most potent naturally occurring anti-coagulants, showed the opposite trend. Conclusions The hypercoagulability of plasma from patients with cirrhosis appears to result from increased levels of factor VIII and decreased levels of protein C—typical features of patients with cirrhosis. These findings might explain the risk for venous thromboembolism in patients with chronic liver disease.

Coagulation factor defects, thrombocytopenia, and thrombocytopathy are associated with cirrhosis. However, bleeding in patients who have cirrhosis does not entirely correlate with abnormal coagulation tests. Recently, it was shown that because of the concomitant abnormalities of the procoagulant and anticoagulant drives, thrombin generation in plasma patients with cirrhosis is normal when assessed with assays that include thrombomodulin (the main protein C activator). However, thrombin is also generated in vivo as a function of platelets, suggesting that thrombocytopenia and thrombocytopathy might affect thrombin generation in patients with cirrhosis. We addressed this issue using an assay that accounts for the contribution of plasma and platelets. The study showed that platelet-rich plasma with platelets adjusted by dilution of autologous platelet-rich into autologous platelet-poor plasma to a standard count (100 × 109/L) generates as much thrombin in patients with cirrhosis as in controls (1,063 nmol/L vs. 1,167 nmol/L; P value not significant). When platelets were adjusted to correspond to whole-blood counts, patients with cirrhosis generated significantly less thrombin than controls (949 nmol/L vs. 1,239 nmol/L; P < .001). Furthermore, thrombin generation correlated with platelet numbers (ρ = 0.50; P < .001). In addition, the amount of thrombin generated as a function of the whole-blood patients' platelet counts increased significantly when the numbers were adjusted to 100 × 109/L (953 nmol/L vs.1,063 nmol/L; P < .001). In conclusion , severe thrombocytopenia may limit thrombin generation in patients with cirrhosis. These findings might justify platelet transfusion in patients with low platelet counts when they bleed spontaneously or before undergoing surgery or liver biopsy. Controlled clinical trials supporting this indication are warranted.

The diagnosis of an underlying chronic myeloproliferative disorder (CMPD) is often problematic in patients with primary extrahepatic portal vein obstruction (EHPVO) or Budd-Chiari syndrome (BCS); indeed, conventional clinical and hematological parameters usually yield insufficient information. To assess the diagnostic contribution of the gain-of-function mutation V617F of the JAK2 gene, 93 patients with EHPVO or BCS were investigated. JAK2 V617F was identified in 35.6% of 73 patients with EHPVO and in 40% of 20 patients with BCS. Taking the JAK2 mutation as a test with the highest positive predictive value for the diagnosis of CMPD, conventional clinical-hematological parameters had a sensitivity for CMPD lower than 48%. Bone marrow (BM) histology provided a diagnosis of CMPD in 41/74 (55.4%) patients, with a sensitivity of 93.5%. Clonality of hematopoiesis as assessed by granulocyte X-chromosome inactivation was present in 65.1% of 43 informative female patients, with a sensitivity of 86.6%. By resolving the sensitivity bias of the JAK2 mutation with the results of BM histology and clonality assay, CMPD was diagnosed in 53% of patients with EHPVO or BCS. In conclusion , CMPD is the major cause of primary EHPVO or BCS. JAK2 V617F is a very reliable and noninvasive molecular marker for CMPD and should be used as a first test for diagnosis.

A reduction in hepatic venous pressure gradient (HVPG) of ≥20% of baseline or to ≤12 mmHg (responders) is associated with a reduced risk of first variceal bleeding. The aim of this study was to evaluate whether this protective effect is maintained in the long term and if it extends to other portal hypertension complications. Seventy-one cirrhotic patients with esophageal varices and without previous variceal bleeding who entered into a program of prophylactic pharmacological therapy and were followed for up to 8 yr were evaluated. All had two separate HVPG measurements, at baseline and after pharmacological therapy with propranolol ± isosorbide mononitrate. Forty-six patients were nonresponders and 25 were responders. Eight-year cumulative probability of being free of first variceal bleeding was higher in responders than in nonresponders (90%vs 45%, P = 0.026). The lack of hemodynamic response and low platelet count were the only independent predictors of first variceal bleeding. Additionally, reduction of HVPG was independently associated with a decreased risk of spontaneous bacterial peritonitis (SBP) or bacteremia. No significant differences in the development of ascites, hepatic encephalopathy, or survival were observed. The hemodynamic response in cirrhotic patients is associated with a sustained reduction in the risk of first variceal bleeding over a long-term follow-up. Reduction of HVPG also correlate with a reduced risk of SBP or bacteremia.

Scant information exists on the role of thrombophilia in extrahepatic portal vein obstruction (EHPVO). We studied 65 patients with EHPVO, 500 with deep vein thrombosis (DVT) of the lower limbs, and 700 healthy controls referred for thrombophilia screening, including the search for gain-of-function mutations in genes encoding coagulation factor V (factor V Leiden) and prothrombin (prothrombin G20210A); antithrombin, protein C, and protein S deficiency; and hyperhomocysteinemia. At least one abnormality in the thrombophilia screening was found in 40% of patients with either EHPVO or lower limb DVT and in 13% of controls, for odds ratios of 4.0 (95% CI, 2.3–7.0) and 4.4 (95% CI, 3.3–5.9), respectively. Statistically significant associations with EHPVO were observed for the prothrombin G20210A mutation (odds ratio, 8.1; 95% CI, 3.8–17.5) and the deficiencies of antithrombin, protein C, or protein S taken together (odds ratio, 4.5; 95% CI, 1.1–18.0). The odds ratio for the prothrombin G20210A was approximately twice that for lower limb DVT. Patients with factor V Leiden had an odds ratio for EHPVO of 0.8 (95% CI, 0.1–6.4) and for lower limb DVT of 7.5 (95% CI, 4.4–13.0). The odds ratio for EHPVO in patients with hyperhomocysteinemia was 2.0 (95% CI, 0.9–4.9). At variance with lower limb DVT, oral contraceptive use was not associated with an increased risk of EHPVO. Myeloproliferative disorders were diagnosed in 35% of patients with EHPVO. In conclusion, the risk for EHPVO is increased in the presence of thrombophilia resulting from the prothrombin G20210A mutation and from the deficiencies of the naturally occurring anticoagulant proteins, but not from factor V Leiden. (HEPATOLOGY 2005;41:603–608.)