Plasma thrombin-antithrombin III complex is associated with the severity of experimental autoimmune encephalomyelitis

Previous studies have shown that activation of blood coagulation and fibrin depositions around CNS vessels are observed in animals with experimental autoimmune encephalomyelitis (EAE), which provides an animal model for human autoimmune demyelinating disorders. We examined the values of peripheral blood fibrinogen, thrombin-antithrombin III complex (TAT), fibrinolytic activity, and fibrin degradation products in Lewis rats with EAE to elucidate the role of the blood coagulation-fibrinolysis system in EAE. Plasma TAT values increased immediately prior to development of symptoms, and decreased according to the improvement of symptoms. There was significant correlation between TAT values and clinical scores of EAE; other markers were not correlated with the symptoms of EAE. These results suggest that plasma TAT levels are sensitive markers of the severity of EAE, and may be useful clinical indicators for the severity of human autoimmune demyelinating disorders.