Association of persistent oxidative stress markers with coronary artery abnormalities in Kawasaki disease patients on follow-up.

BACKGROUND: Kawasaki disease (KD) is associated with long-term vascular sequelae, including persistent endothelial abnormalities. Data on laboratory-based markers of oxidative stress during long-term follow-up of KD patients from developing countries are limited. This study aimed to evaluate extracellular nitric oxide metabolites and neutrophil-derived reactive oxygen species (ROS) in patients with KD during follow-up and to explore their associations with coronary artery abnormalities (CAAs). METHODS: In this prospective, single-centre study, 62 children with KD and 20 age- and gender-matched healthy controls (HC) were enrolled. KD patients were stratified into three groups based on time since diagnosis and further categorised by the presence or absence of CAAs. Serum nitrite and nitrate levels were measured as indicators of extracellular nitric oxide metabolism. Neutrophil ROS production was assessed using a dihydrorhodamine-123 flow cytometric assay. RESULTS: Serum nitrite levels were comparable across the 3 groups (Group 1: 3.46 ± 1.64; Group 2: 5.04 ± 2.55; Group 3: 5.22 ± 3.00) and HC (3.33 ± 1.98) (p = 0.06). The serum nitrate levels in KD patients across all three groups (Group 1: 63.07 ± 41.32; Group 2: 58.63 ± 27.12; Group 3: 64.57 ± 26.36) were also comparable to HC (57.49 ± 8.68) (p = 0.43). In subgroup analysis, serum nitrate levels and serum nitrite levels in KD patients with CAAs and without CAAs were comparable (Group 1: p = 0.60; Group 2: p > 0.99; Group 3: p = 0.10) and (Group 1: p > 0.99; Group 2: p > 0.99; Group 3: p = 0.90), respectively. Neutrophil ROS production (ΔMFI) was increased in KD patients, with a significant rise observed in the intermediate follow-up group 2 (> 1.5-3 years) compared with healthy controls (p = 0.03). No significant correlations were found between oxidative stress markers and systemic inflammatory parameters. CONCLUSION: Children with KD exhibit persistent oxidative stress during follow-up, as evidenced by increased neutrophil ROS production, indicating ongoing cellular oxidative activity. Elevated ROS may serve as an accessible biomarker for CAAs and long-term cardiovascular risk in KD patients on follow-up.