Abstract Objective: To investigate the optimal timing of initial intravenous immunoglobulin (IVIG) treatment in Kawasaki disease (KD) patients. Methods: KD patients were classified as the early group (day 1-4), conventional group (day 5-7), conventional group (day 8-10), and late group (after day 10). Differences among the groups were analyzed by ANOVA and Chi-square analysis. Predictors of IVIG resistance and the optimal cut-off value were determined by multiple logistic regression analyses and receiver operating characteristic (ROC) curve analysis. Results: There were no significant differences in IVIG resistance among the 4 groups (p = 0.335). The sensitivity analysis also confirmed no difference in the IVIG resistance between those who started the initial IVIG ≤ day 7 of illness and those who received IVIG >day 7 of illness (p = 0.761). In addition, patients who received IVIG administration more than 7 days from the onset had a higher proportion of coronary artery abnormalities (p = 0.034) and longer length of hospitalization (p = 0.033) than those who started IVIG administration less than 7 days. The optimal cut-off value of initial IVIG administration time for predicting IVIG resistance was >7 days, with a sensitivity of 75.25% and specificity of 82.41%. Conclusions: IVIG therapy within 7 days of illness is found to be more effective for reducing the risk of coronary artery abnormalities than those who received IVIG >day 7 of illness. IVIG treatment within the 7 days of illness seems to be the optimal therapeutic window of IVIG. However, further prospective studies with long-term follow-up are required.

Abstract Objective Since coronary artery lesions (CALs) are the most severe complication of Kawasaki disease (KD), clinically speaking, early prediction of CALs is crucial. The authors aimed to investigate the predictive value of C-reactive protein (CRP) in predicting CALs in KD patients. Methods KD patients were divided into the CALs group and the non-CALs group. The clinical and laboratory parameters were collected and compared. Multivariate logistic regression analysis was used to determine the independent risk factors of CALs. The receiver operating characteristic curve was applied to determine the optimal cut-off value. Results 851 KD patients who met the inclusion criteria were studied, including 206 in the CALs group and 645 in the non-CALs group. Children in the CALs group had significantly higher CRP levels than the non-CALs group (p< 0.05). Multivariable logistic regression analysis showed that incomplete KD, male, lower hemoglobin, and higher CRP were independent risk factors for predicting CAL (all p< 0.05). The optimal cut-off value of initial serum CRP for predicting CALs was 105.5 mg/L, with a sensitivity of 47.57% and a specificity of 69.61%. In addition, KD patients with high CRP (≥105.5 mg/L) had a higher occurrence of CALs than those with low CRP (<105.5 mg/L) (33% vs 19%, p< 0.001). Conclusion The incidence of CALs was significantly higher in patients with high CRP. CRP is an independent risk factor for CALs formation and may be useful for predicting CALs in KD patients.