Thrombin generation in chronic obstructive pulmonary disease: Dependence on plasma factor composition

BackgroundChronic obstructive pulmonary disease (COPD) is associated with an increased risk for thromboembolic events. We investigated thrombin generation profiles in COPD patients and their dependence on plasma factor/inhibitor composition.MethodsFactors (f) (fII, fV, fVII, fVIII, fIX, fX), antithrombin, protein C (PC) and free tissue factor pathway inhibitor (fTFPI) from 60 COPD patients (aged 64.2 ± 10.1 years; a mean forced expiratory volume in 1 second [FEV1], 55.6 ± 15.8% of predicted values) were compared with those for 43 controls matched for age, sex, weight and smoking. Patients receiving anticoagulation were excluded. Using each individual's plasma coagulation protein composition, tissue factor-initiated thrombin generation was assessed computationally.ResultsCOPD patients had higher fII (115 ± 16 vs 102 ± 10%, p < 0.0001), fV (114 ± 19 vs 102 ± 12%, p = 0.0002), fVII (111 ± 15 vs 102 ± 17%, p = 0.002), fVIII (170 ± 34 vs 115 ± 27%, p < 0.0001), and fIX (119 ± 21 vs 107 ± 17%, p = 0.003), and lower fTFPI (17.7 ± 3.2 vs 18.9 ± 3.2 ng/ml, p = 0.047) compared with controls, while fX, antithrombin, and PC were similar in both groups. Computational thrombin generation profiles showed that compared with controls, COPD patients had higher maximum thrombin levels (+ 28.3%, p < 0.0001), rates of thrombin generation (+ 46.1%, p < 0.0001) and total thrombin formation (+ 14.4%, p < 0.001), together with shorter initiation phase of thrombin generation (p < 0.0001) and the time to maximum thrombin levels (p < 0.0001). Thrombin generation profiles in COPD patients can be normalized via correction of fII, fVIII , fIX and TFPI. The severity of COPD and inflammatory markers were not associated with thrombin generation profiles.ConclusionsProthrombotic phenotype in COPD patients is largely driven by increased prothrombin, fVIII, fIX, and lower fTFPI.