The Clinical Implications Of Serum Ferritin In Kawasaki Disease:A Helpful Biomarker For Evaluating Therapeutic Responsiveness,Coronary Artery Involvement And The Tendency Of Macrophage Activation Syndrome

Background: Kawasaki disease（KD）is an acute,self-limited vascuitis that predominantly affects Asian children less than 5 years old.Serum ferritin（SF）has been widely recognized as an acute phase reactant in systemic inflammatory disease.However,little information is available regarding the association of SF with KD.Methods: 244 KD children were recruited from July 2015 to December 2019 in our hospital.All the KD patients were divided simultaneously into 6 subgroups accordingly to three criteria: clinical course（typical KD,atypical KD）,IVIG responsiveness（IVIG-responsive KD,IVIG-nonresponsive KD）and coronary artery abnormalities（CAAs）presence（non-CAAs KD,CAAs KD）.In addition,243 sex-and age-matched healthy children in the same period were enrolled as the controls.Peripheral blood was collected 24 hours before and 48 hours after IVIG treatment.SF,other classic inflammatory indicators and blood cell counts were detected by chemiluminescence method.Results:（1）SF significantly increased during the acute episode of KD and still maintained an elevated level after IVIG therapy;SF levels were correlated positively with white blood cells counts,erythrocyte sedimentation rate and absolute neutrophil counts.（2）SF significantly elevated in IVIG nonresponders compared with their counterparts;SF had a sensitivity of 57.10% and a specificity of 82.90% at a cutof value of ≥270.25μg/l to predict IVIG-nonresponsive KD and possessed the largest AUC of0.705.（3）SF positively correlated with the internal diameter of coronary artery;SF had a sensitivity of 92.30% and a specificity of 37.70% at a cutof value of≥143.05μg/l to predict KD patients with coronary artery abnormalities（CAAs）and possessed the largest AUC of 0.603.（4）According to the 2004 Swedish guidelines,there were 1patient diagnosed as macrophage activation syndrome（MAS）and 3 patients with MAS tendency;their SF significantly increased with a mean value of979.03±474.19μg/l.Conclusions: SF is implied to be a helpful biomarker for predicting IVIG-nonresponsive KD,CAAs and MAS tendency.A panel containing the available risk factors and SF should be established to enhance the predictive efficacy of KD-associated risks.