Clinical score and transcript abundance patterns identify Kawasaki disease patients who may benefit from addition of methylprednisolone.

Intravenous immunoglobulin (IVIG) treatment-resistant patients are high risk of developing coronary artery lesions with Kawasaki disease. The IVIG-responsive (Group A; n = 6) and IVIG-resistant patients (Group B) were predicted before starting the initial treatment using the Egami scoring system and randomly allocated as a single-IVIG treatment group (group B1; n = 6) or as a IVIG-plus-methylprednisolone (IVMP) combined therapy group (group B2; n = 5). We investigated the transcript abundance in the leukocytes of those patients using a microarray analysis. Five patients in group A and one patient in group B1 responded to initial IVIG treatment. All group B2 patients responded to IVIG-plus-IVMP combined therapy. Before performing these treatments, those transcripts related to IVIG resistance and to the development of coronary artery lesions, such as IL1R, IL18R, oncostatin M, suppressor of cytokine signaling-3, S100A12 protein, carcinoembryonic antigen-related cell adhesion molecule-1, matrix metallopeptidase-9, and polycythemia rubra vera-1, were more abundant in group B patients in comparison with group A patients. Moreover, those transcripts in group B2 patients were more profoundly and broadly suppressed than group B1 patients after treatment. This study elucidated the molecular mechanism of the effectiveness of IVIG-plus-IVMP combined therapy.