Prothrombotic state in patients with severe and prednisolone-dependent asthma.

BACKGROUND

Epidemiologic studies have shown that asthmatic patients, in particular those with severe disease, have increased risk of pulmonary embolism. It is unknown whether these patients have a prothrombotic state under stable conditions.

OBJECTIVE

We sought to compare coagulation and fibrinolysis parameters between healthy subjects and patients with mild, severe, and prednisolone-dependent asthma under stable conditions and to investigate whether hemostatic markers correlate with airway inflammation.

METHODS

In 126 adults (33 healthy control subjects, 31 patients with mild asthma, 32 patients with severe asthma, and 30 patients with prednisolone-dependent asthma) parameters of inflammation (peripheral blood eosinophils and neutrophils) and markers of hemostasis (endogenous thrombin potential [ETP], thrombin-antithrombin complex, plasmin-α2-antiplasmin complex, plasminogen activator inhibitor type 1 [PAI-1], D-dimer, and von Willebrand factor [vWF]) were measured in plasma. One-way ANOVA with the post hoc Bonferroni test was used for group comparison, and linear regression analysis was used for correlations.

RESULTS

We observed increased ETP (121% vs 99%, overall P < .01), plasmin-α2-antiplasmin complex (520 vs 409 μg/L, overall P = .04), PAI-1 (10 vs 7 ng/mL, overall P = .02), and vWF (142% vs 87%, overall P < .01) levels in asthmatic patients compared with healthy control subjects. ETP, PAI-1, and vWF levels increased with increasing asthma severity. In addition, we found a correlation between ETP and vWF with neutrophil but not eosinophil counts.

CONCLUSION

Asthmatic patients have a prothrombotic state that increases with asthma severity. This might explain why patients with asthma, in particular those with severe disease, have an increased risk of venous thromboembolism.