Association of granulocyte colony-stimulating factor and immature neutrophils with treatment resistance in Kawasaki disease

Despite improved treatments for Kawasaki disease (KD), treatment resistance and coronary artery lesions persist. We aimed to identify biomarkers predicting these outcomes under the current treatment strategy based on the RAISE study (Randomized controlled trial to Assess Immunoglobulin plus Steroid Efficacy for Kawasaki disease), which incorporates corticosteroids. We analyzed cytokine profiles and clinical data in a discovery cohort (n = 56) and a validation cohort (n = 110). All patients received intravenous immunoglobulin and aspirin, with high-risk patients (Kobayashi score ≥ 5) additionally receiving prednisolone. In the discovery cohort, the pretreatment percentage of band neutrophils (%Bands) and granulocyte colony-stimulating factor (G-CSF) levels were significantly higher in treatment-resistant patients. %Bands remained associated with treatment resistance after adjustment for the Kobayashi score (odds ratio 1.33, 95% CI 1.10–1.59), with an area under the curve of 0.76. Pretreatment G-CSF and %Bands were positively correlated (Spearman's rho = 0.52, P < 0.001). The validation cohort confirmed that elevated pretreatment %Bands correlated with treatment resistance (P < 0.001). In conclusion, elevated pretreatment %Bands and G-CSF are associated with treatment resistance in KD, and %Bands represent a readily available marker for identifying high-risk patients.