[Thrombin activatable fibrinolysis inhibitor (TAFI) in allergic asthma patients]

Increased thrombin generation occurs in the airways of asthmatic patients. Thrombin activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like proenzyme which after activation by a thrombin-thrombomodulin complex inhibits fibrinolysis. The aim of this study was to evaluate TAFI concentration and activity in plasma of bronchial asthma patients challenged with Dermatophagoides pteronyssinus (Dp) extracts. The study was performed on 23 asthma patients mean age 28.7 +/- 9.8 years with a typical history and positive skin prick test with Dp allergens. Seventeen patients developed both early asthmatic reaction (EAR) and late asthmatic reaction (LAR), 6 patients developed only EAR. Blood was collected before allergen challenge (AO), 1 (A1), 8 (A2) and 24 hours (A3) after allergen challenge. Five healthy persons, mean age 24.5 +/- 3.6 years with negative skin prick tests to common aeroallergens served as negative controls. Healthy controls underwent sham bronchial provocation with 0.9% solution of NaCl. TAFI antigen and activity, levels of thrombin-antithrombin III complexes (TAT) and prothrombin fragments F 1+2 were measured in plasma by ELISA method. At A0 in dual responders mean TAFI concentration (101.4 +/- 23.82%) and activity (19.6 +/- 5.92 microg/ml) were higher than in healthy controls (69.35 +/- 21.49%; p < 0.05 and 10.49 +/- 3.53 microg/ml; p = 0.01; respectively). Significant fall in TAFI plasma concentration was detected at A1 and the decreased concentration of TAFI persisted until A3 (85.15 +/- 26.36%; p < 0.05). No significant change in plasma TAFI concentration was observed in healthy controls or in patients who responded with an EAR only. Allergen induced inflammation is associated with significant changes in plasma TAFI concentration.