Predicting Intravenous Immunoglobulin Resistance Among North American Children Hospitalized With Kawasaki Disease

OBJECTIVE The Kobayashi score (KS) is the most widely used tool for predicting intravenous immunoglobulin (IVIG) resistance in Kawasaki disease (KD). The KS has shown good sensitivity (86%) and specificity (68%) in Japanese children; however, its use is limited outside of Japan. No models accurately predict IVIG resistance of children with KD in the United States. We sought to develop and test a novel scoring system to predict IVIG resistance in hospitalized children with KD. METHODS A retrospective chart review was conducted of all children diagnosed with KD from January 2000 to December 2015. Subjects were divided into 2 groups: IVIG susceptible or resistant. Variables that differed between the groups were identified and used to create a “new score” to predict resistance to IVIG. The new score was then compared with the KS and performance characteristics were determined. RESULTS A total of 208 subjects were reviewed. White blood cell count, neutrophil percentage, age, and serum albumin were used in the new score with equal weighting. Overall, the new score achieved improved sensitivity (54% vs 26%) and similar specificity (69% vs 74%) compared with the KS in predicting IVIG resistance in hospitalized children diagnosed with KD. CONCLUSIONS Predicting IVIG resistance in children diagnosed with KD remains challenging. The KS has low sensitivity in predicting IVIG resistance in children with KD in the United States. The new score resulted in improved sensitivity, but many children with true IVIG resistance may be missed. Further research is needed to improve IVIG resistance prediction. ABBREVIATIONS ALT, alanine aminotransferase; AST, aspartate transaminase; CAA, coronary artery aneurysm; IVIG, intravenous immunoglobulin; KD, Kawasaki disease; KS, Kobayashi score; ROC, receiver operator curve; WBC, white blood cell; WNY, Western New York.