Antibody Profiling of Kawasaki Disease Using Escherichia coli Proteome Microarrays

Abstract

Kawasaki disease (KD) is a form of systemic vasculitis that generally occurs in children under 5 years old. Currently, KD is still diagnosed according to its clinical symptoms, including prolonged fever, skin rash, conjunctivitis, neck lymphadenopathy, palm erythema, and oral mucosa changes. Because KD is a type of inflammation without specific marker for diagnosis, we plan to profile the plasma antibodies by using <i>E. coli</i> proteome microarray and analyze the differences between KD and healthy subjects. Plasmas were collected from KD patient before intravenous immunoglobulin treatment (KD1), at least 3 weeks after treatment (KD3), nonfever control (NC), and fever control (FC) children. The initial screening, which consisted of 20 KD1, 20 KD3, 20 NC, and 20 FC, were explored using <i>E. coli</i> proteome microarrays (∼4200 unique proteins). About ∼70 proteins were shown to have high accuracy, <i>e.g.</i> 0.78∼0.92, with regard to separating KD1, KD3, NC, and FC. Those proteins were then purified to fabricate KD focus arrays for training (<i>n</i> = 20 each) and blind-testing (<i>n</i> = 20 each). It only took 125 pl of plasma, less than a drop of blood, in the focus array assays. The AUC scores for blind tests of KD1 <i>versus</i> NC (17 protein markers), KD1 <i>versus</i> FC (20 protein markers), KD3 <i>versus</i> NC (9 protein markers), and KD1 <i>versus</i> KD3 (6 protein markers) were 0.84, 0.75, 0.99 and 0.98, respectively. This study is the first to profile plasma antibodies in KD and demonstrate that an <i>E. coli</i> proteome microarray can screen differences among patients with KD, nonfever controls, and fever controls.