LAUSR

Objectives: Kawasaki disease (KD) is an acute systemic vasculitis that most commonly causes acquired cardiac disease in children in developed countries. The most highly recommended treatment for KD is 2 g/kg intravenous immunoglobulin (IVIG). Hyponatremia in patients with KD in the acute phase is known to be associated with IVIG resistance and coronary artery abnormalities (CAA). There are two types of IVIG, sodium-containing (high Na) and sodium-trace (low Na) preparations. However, few studies have compared the effects of these two preparations for superiority. The purpose of this study was to compare outcomes between high and low Na IVIG preparations in KD children using a national inpatient database in Japan. Methods: We used the Diagnostic Procedure Combination database to identify KD patients treated with IVIG between 2010 and 2017. We identified those receiving high and low Na preparations of IVIG as an initial treatment. Outcomes included proportion of CAA, IVIG resistance, adverse effects, length of stay, and medical cost. Propensity score-matched analyses were conducted to compare the outcomes between the two groups. Instrumental variable analyses were performed to confirm the results. Results: We identified 47,292 patients with KD and created 23646 propensity score-matched pairs between the high and low Na IVIG groups. There were significant differences in proportions of CAA (2.5% vs. 2.9%; p=0.016) and IVIG resistance (23.8% vs. 24.9%; p=0.006) between the two groups. However, there were no significant differences in length of stay or medical cost. The instrumental variable analyses confirmed that high Na IVIG was significantly associated with lower proportion of CAA compared with low Na IVIG (odds ratio, 1.69; p<0.001). Conclusions: The present study suggests that high Na IVIG is potentially effective for reducing the proportion of CAA in KD patients. Prospective studies are warranted to confirm the effectiveness observed in this study.