Predictors of intravenous immunoglobulin resistance and coronary artery aneurysm in patients with Kawasaki disease

Background: Patients with Kawasaki disease (KD) who have intravenous immunoglobulin (IVIG) resistance are at increased risk for development of coronary artery abnormalities. Although in Japan several risk scoring systems are able to predict patients with IVIG-resistant (KD), they do not accurately predict non-responders in other regions. Aim: The objectives of this study were to determine the predictors of IVIG resistance and coronary artery aneurysm (CAA) and to develop risk scoring systems for predicting IVIG-resistant KD in the Thai population. Methods: A total of 217 patients with KD between 2004 and 2014 were retrospectively reviewed. All patients including 116 with complete KD and 101 with incomplete KD were diagnosed and treated with 2g/kg IVIG. Results: Twenty-six patients (85% male) with IVIG-resistant KD had a reduced platelet count and increased neutrophil-to-lymphocyte ratio compared with those with an IVIG response. Fifty-five patients with CAA eight weeks after diagnosis had a longer duration of fever (8days) and increased platelet count (>= 550 x 10(9)/L) than those with non-CAA. Based on analysis by multivariate logistic regression, haematocrit <= 30%, platelet count <= 300 x 10(9)/L, aspartate aminotransferase >= 40 U/L and neutrophil-to-lymphocyte ratio >= 3.2 were predictors of IVIG resistance. The new scoring system using these significant factors had a sensitivity of 80.8% and a specificity of 66.8% in identifying patients with IVIG resistance. Japanese scoring systems had low sensitivity and specificity. Conclusions: KD patients with reduced mean haemoglobin, increased AST level, increased neutrophil-to-lymphocyte ratio and reduced platelet count should be considered for conjunctive therapy such as a corticosteroid in combination with standard treatment. Duration of fever >= 8days and platelet count >= 550 x 10(9)/L were predictors of CAA. To prevent cardiovascular complications, patients should be treated promptly after KD has been diagnosed.