Abstract: Objective:To investigate the differences and clinical significance of platelet (PLT), interferon-gamma(IFN-γ), and interleukin-6(IL-6)expression levels between gammaglobulin non-responsive and sensitive children with Kawasaki disease.Methods:Ninety-nine Kawasaki disease patients admitted to Zhongshan Hospital Xiamen University from May 2019 to June 2022 were selected and divided into non-responsive group(24 cases)and sensitive group(75 cases)according to the response of gammaglobulin treatment.Baseline levels and the expression levels of PLT, IFN-γ and IL-6 at 12 h and 36 h were compared between the two groups.Logistic regression was used to analyze the influencing factors related to gammaglobulin non-response in Kawasaki disease, receiver operating characteristic curve(ROC)was used to analyze the value of PLT, IFN-γ, IL-6 and combined prediction of gammaglobulin non-response in Kawasaki disease, and DeLong was used to test the predictive value of different regimens.Clinical decision curve analysis(DCA)was used to analyze the clinical utility of PLT+IFN-γ+IL-6 regimen to predict gammaglobulin reactivity in Kawasaki disease.Results:The expression levels of PLT, IFN-γ and IL-6 at 12 h and 36 h in the non-responsive group were not statistically significant compared with baseline level (P> 0.05); the expression levels of PLT, IFN-γ and IL-6 in sensitive group at 12 h and 36 h were lower than baseline levels (P< 0.05); baseline level and expression levels of PLT, IFN-γ and IL-6 at12 h and 36 h in non-responsive group were higher than those in sensitive group(P< 0.05); baseline PLT, IFN-γ and IL-6 were all independent relevant influencing factors for non-response to Kawasaki disease gammaglobulin(P< 0.05); the area under the ROC curve (AUC) of PLT, IFN-γ, IL-6 and combination was 0.818, 0.767, 0.712 and 0.915, respectively, the AUC of PLT+IFN-γ+IL-6 was higher than that of IFN-γ and IL-6(P< 0.05), but the difference with PLT was not statistically significant (P> 0.05); there was a net positive clinical benefit of using the PLT+IFN-γ+IL-6 regimen to predict gammaglobulin non-response in Kawasaki disease.Conclusion:There are significant differences in the expression levels of PLT, IFN-γ and IL-6 in children with Kawasaki disease who do not respond to gammaglobulin and those who are sensitive to gammaglobulin, which is related to the therapeutic reactivity of the children.Combined detection of PLT, IFN-γ and IL-6 can predict the therapeutic response of gammaglobulin.