Risk factors and derived formosa score for intravenous immunoglobulin unresponsiveness in Taiwanese children with Kawasaki disease.

Background/purpose: Kawasaki disease (KD) is the most common pediatric vasculitis. The study aimed to identify the risk factors of intravenous immunoglobulin (IVIG) unresponsiveness from the initial clinical parameters of the Taiwanese KD patients.

Methods: We enrolled 248 KD (development dataset: 181, validation: 67) patients who received IVIG within 10 days after fever onset. IVIG unresponsiveness was defined by persistent fever beyond 24 hours after IVIG or recrudescent fever with KD symptoms.

Results: From the development dataset (181 patients), IVIG unresponsiveness was noted in 22 patients (12.1%). The preIVIG levels of albumin, percentage of neutrophils, and positive lymphadenopathy were identified with highest risk for IVIG unresponsiveness. These three variables were used to construct a three-variable logistic regression model, which yielded an area under the receiver-operating-characteristics curve of 0.87. These three variables were further used to generate a composite scoring model (Formosa score) which yielded a sensitivity of 90.9% and specificity of 81.3% for a cut-off point of three or more. Validation in an independent cohort (67 KD patients) yielded sensitivity and specificity of 71.4% and 81.0%, respectively.

Conclusion: We have established a simple three-variable Formosa score for KD patients to identify early those at risk of IVIG unresponsiveness for timely aggressive immunomodulation initially.