The Significance of Thrombin Activable Fibrinolysis Inhibitor in Ischemic Stroke

Kim, Young Chul; Lee, Young Kyung; Park, Min Jeong; Kang, Hee Jung; Kang, Sung Ha; Cho, Hyoun Chan; Lee, Byung Chul; Yu, Kyung Ho

Abstract

BACKGROUND
Thrombin/thrombomodulin complex activates thrombin activable fibrinolysis inhibitor (TAFI) to active TAFI (TAFIa), which in turn catalyzes the hydrolysis of C-terminal lysine residues of partially degraded fibrin. The fibrin that is partially degraded by TAFIa is not degraded by plasmin. Thus, TAFI inhibits fibrinolysis. An increase in plasma TAFI level is suggested to be associated with thrombotic disorders. In this study, we measured TAFI levels and investigated the distribution of C+1542G polymorphism in Korean patients with ischemic stoke. And, we intended to investigated the role of TAFI in the occurrence of ischemic stroke. METHODS: We enrolled 44 patients who had experienced ischemic stroke episodes more than 6 month ago and had not been treated with oral anticoagulant. We also tested 44 age and sex-matched healthy controls. TAFI antigen levels were measured by an enzyme-linked immunosorbent assay (VisulizeTM TAFI antigen kit; Affinity Biologicals Inc., Ancaster, Canada) and TAFI activity levels were measured by a chromogenic assay (Actichrome TAFI activity kit ; American diagnostica Inc., CT, USA). Genotyping of C+1542G polymorphism was performed by an allele-specific polymerase chain reaction. RESULTS: The range of TAFI antigen was 2.4-12.7microgram/mL (mean+/-2SD) and that of TAFI activity was 4.9-17.9microgram/mL (mean+/-2SD) in healthy controls. TAFI antigen level was not correlated with TAFI activity. TAFI activity was the highest in CC polymorphism and the lowest in GG polymorphism (P= 0.03). The levels of TAFI antigen and activity were lower in the patients with ischemic stroke than in healty controls, but the difference was not statistically significant. There was no difference in the distribution of C+1542G polymorphism between the patients with ischemic stroke and healthy persons. CONCLUSIONS: In this study, TAFI antigen and activity were not significantly associated with the occurrence of ischemic stoke in Korean. And, TAFI may not be a risk factor for ischemic stroke in the Korean population.