Analysis of potential risk factors associated with nonresponse to initial intravenous immunoglobulin treatment among Kawasaki disease patients in Japan.

BACKGROUND: Some Kawasaki disease (KD) patients do not respond to initial treatment with intravenous immunoglobulin (IVIG). The purpose of this study was to determine potential risk factors associated with IVIG nonresponse among KD patients in Japan.
METHODS: Data were obtained from questionnaires used for the 18th nationwide KD survey of patients who visited hospitals in Japan from 2003 through 2004. Data for patients who met the case definition for KD and received 2 g/kg single infusion IVIG as the initial treatment within 10 days of illness were analyzed. IVIG nonresponders were defined as patients who needed secondary treatment after initial IVIG administration.
RESULTS: Among 15,940 KD patients in Japan during 2003-2004, 6330 patients received 2 g/kg single infusion IVIG within 10 days of illness onset. IVIG nonresponders accounted for 20.3% of them (n = 1286). Male sex [odds ratio (OR), 1.21, 95% confidence interval (CI), 1.06-1.37], receipt of the initial IVIG before the fifth day of illness (OR: 1.89, 95% CI: 1.66-2.15), and having recurrent KD (OR: 1.38, 95% CI: 1.00-1.90) were significantly associated with IVIG nonresponse. In addition, IVIG nonresponders had significantly higher risks for coronary artery aneurysms (OR: 10.38, 95% CI: 6.98-15.45) or giant coronary artery aneurysms (OR: 54.06, 95% CI: 12.84-227.65).
CONCLUSIONS: Physicians should consider potential IVIG nonresponse among recurrent KD patients or KD patients diagnosed and treated before the fifth day of illness, particularly if they are boys and have laboratory values associated with nonresponse such as low platelet count, and elevated alanine aminotransferase and C-reactive protein. Some of these patients may benefit from administration of the alternative secondary treatment early during the illness along with the initial IVIG treatment.