Abstract 93: Analysis of Serum Levels of Procalcitonin and Serum Amyloid A as Biomarkers of Intravenous immunoglobulin-resistant Kawasaki Disease

Abstract

Aim: Immune globulin is the most effective treatment of Kawasaki Disease, however, 15-20% of patients with Kawasaki disease (KD) is resistant to 2g/kg of IVIG (refractory case), and those patients are high risk for complication of coronary artery abnormalities, to detect these refractory KD before treatment of acute phase is very important to determine their treatment, but the methods to predict the refractory case is not yet established. We analyze the relation of IVIG-resistant Kawasaki disease and serum levels of procalcitonin (PCT) or serum amyloid A (SAA). Method: 192 patients with KD were involved in this study, and 48 were IVIG-resistant cases. Refractory case was defined as patients who needed additional treatment with IVIG and/or steroid after the first treatment with total 2g/kg of IVIG. Serum levels of PCT and SAA were measured before treatment, and the relationship to clinical course was analyzed. Result: Median level of PCT of patients with IVIG-resistant KD was 2.24 ng/ml and those with non- IVIG-resistant KD was 0.47 ng/ml, and median levels of PCT of patients with IVIG-resistant KD was significantly higher than those with non- IVIG-resistant KD (p<0.01). Median level of SAA of patients with IVIG-resistant KD was 753.6 μg/ml and those with non- IVIG-resistant KD was 635.9μg/ml and there was no significant difference. We compared the accuracy of prediction of IVIG resistant KD by PCT and SAA using receiver operating characteristic (ROC) analysis. The areas under the receiver operating characteristic curve(AUC) of PCT, SAA and CRP was 0.75, 0.57 and 0.63 respectively. For identification of IVIG-resistant patients, a cut-off point, sensitivity and specificity of PCT, SAA and CRP were as follows, 1.5 ng/ml, 77% and 61%, 444 μg/ml, 83% and 32% and 7.7 mg/dl, 73% and 59%, respectively. Conclusion: As PCT levels of patients with IVIG-resistant Kawasaki disease were significantly higher than those with non- IVIG-resistant KD, PCT could be one of the predictor of IVIG-resistant KD.