Elevated serum levels of macrophage colony-stimulating factor in patients with Kawasaki disease complicated by cardiac lesions.

OBJECTIVE The main pathogenic characteristic of Kawasaki disease (KD) is the activation of mononuclear phagocytes. The cytokines produced by activated monocytes/macrophages elicit proinflammatory and prothrombotic responses in endothelial cells. Thus, we speculated that macrophage colony-stimulating factor (M-CSF), derived from monocytes/macrophages or vascular endothelial cells, might play an important role in the pathogenesis of the acute phase of KD. The aim of this study was to investigate the possible role of M-CSF in the pathogenesis of KD and to elucidate the relationship between serum M-CSF levels and clinical features and cardiac lesions. METHODS Using ELISA, we serially assayed M-CSF and several cytokines, including interleukin-6, interleukin-8, tumor necrosis factor-alpha and interferon-gamma in the sera of 32 KD patients aged 2 months to 4 years. RESULTS The serum M-CSF level during the first week of illness was significantly higher than during the second week or thereafter (first week, median 1710.0; second week, 1121.0; third week, 867.3; fourth week, 909.4 U/ml, p<0.001) in our KD patients. Serum M-CSF levels during the first week of illness were also higher in patients with mitral and/or aortic valvular insufficiency than in patients without cardiac complications. Furthermore, serum M-CSF levels in patients with persistent coronary dilatation were higher than in those with no cardiac complications. CONCLUSION M-CSF plays a critical role in the pathogenesis of KD and can be used as an indicator for the risks of valvulitis and coronary arteritis.