A nomogram based on serum CHI3L1 for predicting IVIG nonresponse in children with Kawasaki disease

To investigate the value of serum chitinase-3-like protein 1 (CHI3L1) in predicting intravenous immunoglobulin (IVIG) nonresponse in children with Kawasaki disease (KD) and to develop a prediction model incorporating CHI3L1.This study enrolled 152 KD children (23 IVIG nonresponders, 129 IVIG-responders). Serum CHI3L1 levels were measured before IVIG infusion using an enzyme-linked immunosorbent assay (ELISA). Independent predictors were identified by univariate and multivariate logistic regression analyses, and a nomogram was constructed. The model performance was evaluated by the area under the receiver operating characteristic curve (AUC), calibration plot, decision curve analysis (DCA), clinical impact curve (CIC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI).Serum CHI3L1 levels were significantly higher in the IVIG-nonresponsive group. Multivariate analysis identified CHI3L1 and C-reactive protein (CRP) as independent risk factors for IVIG nonresponse. The nomogram incorporating these two factors achieved an AUC of 0.83, with a sensitivity of 0.91 and a specificity of 0.67. Compared to CHI3L1 or CRP alone, the nomogram provided significant NRI and IDI. Both the calibration curve and DCA demonstrated favorable accuracy and clinical utility of the model.

Serum CHI3L1 is an independent predictor of IVIG nonresponse in KD. The nomogram combining CHI3L1 and CRP shows favorable predictive performance and may serve as a practical tool for early identification of IVIG-nonresponsive patients.

• Kawasaki disease (KD) is the leading cause of acquired pediatric heart disease, and IVIG nonresponse increases the risk of coronary artery lesions. • Several biomarkers and scoring systems have been proposed to predict IVIG resistance, but their generalizability and performance remain limited.

• Serum CHI3L1, a chitinase family protein, is identified for the first time as an independent predictor of IVIG nonresponse in KD. • A novel nomogram integrating CHI3L1 and CRP demonstrates excellent predictive performance, with high sensitivity and improved net reclassification.