Homocysteine is a strong and independent risk factor for cardiovascular disease. The deleterious effects of homocysteine included endothelial dysfunction, arterial intimal-medial thickening, wall stiffness and procoagulant activity. However, the precise mechanism responsible for homocysteine release in children with coronary artery disease is still unknown. The purpose of this study was to investigate serum homocysteine and tumor necrosis factor(TNF)-α levels and identify whether these levels had any association with the development of coronary artery lesions in Kawasaki disease(KD).

Serum homocysteine and TNF-α levels were measured in 24 KD patients(group 1, eight patients with normal coronary artery; group 2, 16 patients with coronary artery lesions) and 21 controls(group 3, 10 afebrile controls; group 4, 11 febrile controls). Blood samples were drawn from each study group before and after intravenous immunoglobulin(IVIG) therapy and in the convalescent stage.

The homocysteine levels before IVIG therapy were significantly higher in group 1 than in group 3, and in group 2 than in group 3 and 4. The TNF-α levels before IVIG therapy were significantly higher in group 2 than group 3 and 4. Serum homocysteine and TNF-α levels were highest in group 2 before IVIG therapy. In the acute KD patients, serum homocysteine levels correlated significantly with TNF-α levels.

The increased serum homocysteine levels in the acute stage increase the susceptibility to coronary arterial lesions in KD. TNF-α may also play an important role in the formation of coronary arterial lesions in KD.