BACKGROUND: Treatment of acute Kawasaki disease (KD) with intravenous
immunoglobulin (IVIG) reduces the risk of coronary artery abnormalities. However, patients who are resistant to IVIG are at risk for developing coronary artery aneurysms. It was reported that the neutrophils were identified in the coronary arterial lesions of the patients who died 10 days after the onset of KD, suggesting that neutrophil elastase might play an important role in the early stage of KD. Sivelestat sodium (Sivelestat-Na) is a small molecular weight neutrophil elastase inhibitor. The purpose of this study is to investigate the safety and efficacy of Sivelestat sodium for IVIG-resistant KD. METHODS and RESULTS: Seventy patients of KD were initially treated with IVIG at 2g/kg and aspirin (30mg/kg/day) from January 2006 through December 2008. Of 70 patients, 18 patients who had persistent or recurrent fever after initial treatment were treated with re-IVIG at 2g/kg in a single dose plus Sivelestat-Na. Sivelestat-Na treatment at 0.2mg/kg/hr for 5 consecutive days. Six of the 18 patients had persistent fever, so then they were treated with Prednisolone at 2mg/kg/day. Four of the 18 patients had coronary aneurysms, but 3 of 4 patients already had coronary abnormalities before Sivelestat-Na treatment. Ultimately, only one patient with Sivelestat-Na treatment started before 10 days of illness had moderate size of coronary aneurysm. Significant side effects of Sivelestat-Na have not been documented. CONCLUSiONS: Sivelestat-Na treatment may be one of effective treatment for
IVIG-resistant patients.