OBJECTIVE: Immunovasculitis is a pathologic process of Kawasaki disease (KD) in the early stage and it is more likely to be resulted from abnormal immunoactivation. It is thus speculated that the serum levels of some cytokines have changed before immunovasculitis occurs, suggesting the cytokines may be useful markers for the early diagnosis of KD. In this study, we measured the serum levels of soluble interleukin-2 receptors (sIL-2R), interleukin-6 (IL-6) and high-sensitive C-reactive protein (hs-CRP) in patients with KD to evaluate the significance of these cytokines in the early diagnosis of KD. METHODS: Serum levels of sIL-2R and IL-6 were measured by rapid one-step sandwich enzyme immunoassay and the serum hs-CRP level was measured by Dade Behring BN ProSpec in 32 KD patients before and after intravenous immunoglobulin (IVIG) therapy. Twenty healthy children were used as the controls. RESULTS: Before IVIG therapy serum levels of sIL-2R (9253.41±2568.38 pg/mL vs 2161.53±696.92 pg/mL; P<0.05), IL-6 (57.19±45.78 ng/mL vs 7.04±1.69 ng/mL; P<0.05) and hs-CRP (117.69 ±42.05 mg/L vs 1.15±0.54 mg/L; P<0.05) in KD patients were significantly higher than those in healthy controls. After IVIG therapy in KD patients serum IL-6 levels returned to normal and sIL-2R and hs-CRP levels decreased significantly but remained significantly higher than controls( P<0.05 ). There was a positive correlation between sIL-2R and hs-CRP levels (r=0.60, P<0.01). IL-6 levels positively correlated with hs-CRP levels in KD patients before IVIG therapy (r=0.68, P<0.01). CONCLUSIONS: sIL-2R, IL-6 and hs-CRP are activated in the development of KD, and they may be of important value in the early diagnosis of KD.