Risk factors for non-response to initial IVIG plus methylprednisolone therapy in children with Kawasaki disease

IVIG plus corticosteroids is recommended as the initial intensified therapy for high-risk IVIG-resistant Kawasaki disease (KD) patients. However, some patients still require additional rescue therapy despite this treatment. This study aimed to identify risk factors associated with non-response to initial IVIG plus methylprednisolone therapy in high-risk refractory KD patients.

High-risk IVIG-resistant patients with KD 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 a resistance group and a response group after treatment. Propensity score matching 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.

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 (≥20 µmol/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%.

TBil (≥20 µmol/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.