Urinary neopterin as a predictive marker of coronary artery abnormalities in Kawasaki syndrome.

We investigated whether urinary neopterin concentrations respond to the pathological conditions (especially coronary artery dilatation) of Kawasaki syndrome. All of 29 children with Kawasaki syndrome had very high urinary neopterin concentrations. Increased urinary neopterin concentrations coincided with fever and with monocytosis in peripheral blood. The urinary neopterin excretion peaking within the first 8 days after onset correlated with the development of coronary artery dilatation. Increased urinary neopterin concentrations indicate that cell-mediated immunity is activated in patients with Kawasaki syndrome. Endogenous interferon-gamma and activation of monocytes/macrophages may play a role in the pathogenesis of Kawasaki syndrome. Not only do neopterin concentrations correlate with symptoms in the acute phase of Kawasaki syndrome, they also act as a predictive marker of coronary artery abnormalities in affected patients.