Activation of the Blood Coagulation System in Patients with Chronic Spontaneous Urticaria.

BACKGROUND

Ninty-five percent of chronic spontaneous urticaria (CSU) patients presented with signs of thrombin generation, and autologous plasma skin tests score positive. The aim of this study was to assess the initiators of blood coagulation that lead to thrombin generation and fibrinolysis in CSU patients.

METHODS

The plasma level of activated factor VII, activator factor XII, fragment F1+2, and D-dimer were measured and analyzed in 103 patients with CSU and 76 control subjects.

RESULTS

Mean D-dimer plasma levels were higher in patients than controls (0.41 ± 0.44 μg/mL vs. 0.21 ± 0.26 μg/ mL; p < 0.001). Mean F1+2 plasma levels were higher in patients than controls (11.17 ± 17.65 nM vs. 5.97 ± 9.42 nM; p = 0.048). Mean FVIIa plasma levels were higher in patients than controls (4.09 ± 4.22 ng/mL vs. 2.97 ± 1.59 ng/mL; p = 0.031). However, no significant difference was found on FXIIa plasma levels. On the other hand, all the coagulation factors (D-dimer, FVIIa, and F1+2) were significantly correlated with disease severity.

CONCLUSIONS

The extrinsic pathway of the clotting cascade is activated in CSU and is correlated with the disease severity. The involvement of the coagulation pathway in CSU opens new perspectives for a better understanding of the pathogenesis and treatment of the disease.