High levels of factor VIII and risk of extra-hepatic portal vein obstruction.

BACKGROUND/AIMS: High levels of coagulation factor VIII are a risk factor for lower-limb deep vein thrombosis (DVT). Their role in extra-hepatic portal vein obstruction (EHPVO) is not established. METHODS: Factor VIII was measured in 85 patients with EHPVO (primary in 58 and complicating liver cirrhosis in 27), in 200 with lower-limb DVT, in 108 with liver cirrhosis without thrombosis and in 200 healthy controls. RESULTS: Factor VIII levels were significantly higher in patients with primary EHPVO (138 IU/dL, range 86-366), EHPVO and cirrhosis (147 IU/dL, 95-242), lower-limb DVT (140 IU/dL, 64-400) and cirrhosis alone (160 IU/dL, 43-446) than in controls (112 IU/dL, 62-250, p<0.001). When factor VIII exceeded 129 IU/dL (66th percentile), the odds ratios were 10.5 (95%CI 3.3-33.4) for primary EHPVO, 6.0 (1.2-30.7) for EHPVO and cirrhosis, 5.0 (2.6-9.4) for lower-limb DVT. After exclusion of the effect of the acute phase reaction, the odds ratio for primary EHPVO was 4.2 (0.8-22.7), and was 8.7 (0.9-80.5) after exclusion also of patients with chronic myeloproliferative disorders. CONCLUSIONS: High factor VIII levels are independently associated with an increased risk for EHPVO. The risk of EHPVO increased with increasing factor VIII levels and was only partially dependent on the acute phase reaction.