HYPERCOAGULABLE STATE IN PATIENTS WITH TAKAYASUS-ARTERITIS

Thrombus formation is recognized pathologically in the affected arteri es and is supposed to play a major role in the pathogenesis of Takayas u's arteritis; however, hemostatic conditions in this disorder have no t been elucidated fully. We determined plasma levels of molecular mark ers for platelet activity (platelet factor 4; PF4, beta-thromboglobuli n; beta TG), thrombotic status (thrombin-antithrombin III complex; TAT , fibrinopeptide A; FPA), fibrinolytic status (plasmin-alpha(2)-plasmi n inhibitor complex; PIC, D-dimer), and endothelial injury (von Willeb rand factor antigen; vWF:Ag, thrombomodulin; TM) in 30 patients with T akayasu's arteritis and in 20 age-matched control subjects. Plasma lev els of PF4, beta TG, TAT, FPA and D-dimer, but not PIC, in patients wi th Takayasu's arteritis were substantially higher than those in normal control subjects. The levels of these markers were not different betw een the active and inactive stages of the disease. Plasma levels of vW F:Ag in patients with Takayasu's arteritis did not differ significantl y from those in normal subjects, and plasma levels of TM were signific antly lower than those in normal subjects. In patients with Takayasu's arteritis, platelet and coagulation activities are significantly incr eased, leading to hypercoagulable state and thrombus formation, althou gh there is little, if any, endothelial damage.