Increased plasma endothelin levels in Kawasaki disease: a possible marker for Kawasaki disease.

Plasma immunoreactive endothelin (iET) levels were investigated in patients with Kawasaki disease (KD). The iET level was 2.49 +/- 0.13 pg/mL in KD patients and 1.32 +/- 0.06 in age-matched control subjects, showing a significant increase with KD. The iET level was not increased in patients with febrile inflammatory diseases of bacterial origin without KD (non-KD group). Parameters indicating an inflammatory reaction, such as C-reactive protein, platelet count, white blood cell count, and interleukin-6 level, were increased in the KD patients. However, they were similarly increased in the patients with febrile diseases of bacterial origin and showed no significant differences between the two groups. This study is the first to report that plasma iET levels are elevated in a disease mainly involving vasculitis. These results suggest that blood iET levels are increased in KD patients as a result of the associated vascular endothelial damage and that iET can be a useful marker for the diagnosis of KD.