Changes in Serum Levels of NINJ1 and HMGB1 in Children with Kawasaki Disease and Their Clinical Significance

Purpose: Kawasaki disease (KD) is an acute systemic vasculitis that can result in coronary artery lesions (CALs). This study aims to explore the expression levels of serum Ninjurin-1 (NINJ1) and high-mobility group box 1 (HMGB1) in the acute phase of KD and evaluate their clinical significance. Methods: A total of 180 children were enrolled, comprising 113 KD patients, 35 healthy controls (HCs), and 32 febrile controls whose clinical data were collected. Serum levels of NINJ1, HMGB1, Lactate Dehydrogenase (LDH), and routine inflammatory markers were compared across groups. Serum levels of NINJ1 and HMGB1 were measured via ELISA. Correlations were analyzed using Spearman tests. The diagnostic and predictive performance of biomarkers was assessed using Receiver Operating Characteristic (ROC) curve analyses. Results: Serum levels of NINJ1 and HMGB1 were significantly elevated in the KD group compared with both the HC and FC groups (all p < 0.001). NINJ1 levels were positively correlated with the z-scores of coronary arteries and were significantly higher in the CAL subgroup than in the non-CAL subgroup (p = 0.004). A strong positive correlation was observed between serum NINJ1 and HMGB1 levels in the KD group (p < 0.001). Conclusions: Elevated serum NINJ1 levels during the acute phase of KD were associated with the presence of CALs, while HMGB1 shows promise in differentiating KD from other febrile illnesses. These findings collectively suggest that the NINJ1-HMGB1 axis may offer novel insights into the mechanisms underlying KD vasculitis, supporting further investigation into its potential clinical relevance.