O1014: Risk Factors for Non-response to Initial Intravenous Immunoglobulin Plus Methylprednisolone Therapy in Children with Kawasaki Disease

Background: Intravenous immunoglobulin (IVIG) plus corticosteroids is recommended as initial intensified therapy for high-risk IVIG-resistant Kawasaki disease (KD) patients. However, studies evaluating responsiveness to this therapy are rare.

Methods: High-risk IVIG-resistant KD patients were assessed by both the Yang score and Kobayashi score before treatment between January 2020 and June 2024. All selected patients received IVIG plus methylprednisolone. Patients were divided into resistance group and response group after treatment. Propensity score matching (PSM) was performed at a 1:4 ratio, matching by age and sex. Logistic regression analysis identified independent risk factors associated with IVIG plus methylprednisolone resistance.

Results: Of 1511 KD patients, 150 patients with high-risk IVIG-resistance, 13 were resistant to initial IVIG plus methylprednisolone, while 137 responded. Total bilirubin (TBil) (OR 1.024, 95% CI: 1.003 - 1.048 P=0.031) and the Yang score (OR 1.575, 95% CI: 1.204-2.190, P=0.002) were independent risk factors for resistance. Interleukin-6 (IL-6) was also a potential risk factor (OR 1.002, 95% CI: 1.000 - 1.005, P=0.054). The area under the ROC curve (AUC) for TBil (≥20μmol/L) was 0.745 (95% CI: 0.602 - 0.888), with a sensitivity of 84.6% and specificity of 71.2%. The AUC for the Yang score (≥12) was 0.745 (95% CI: 0.583 - 0.906)，with both sensitivity and specificity at 76.9%.

Conclusion: TBil (≥20μmol/L), Yang score (≥12), and elevated IL-6 levels are independent risk factors for resistance to IVIG plus methylprednisolone. These findings provide valuable insights for pediatricians in selecting individualized treatment strategies for high-risk refractory KD patients.