Aberrant peripheral immune responses in acute Kawasaki disease with single-cell sequencing

Wang, Zhen; Xie, Lijian; Song, Sirui; Chen, Liqin; Li, Guang; Liu, Jia; Xiao, Tingting; Zhang, Hong; Huang, Yujuan; Ding, Guohui; Li, Yixue; Huang, Min

Kawasaki disease (KD) is the most common cause of acquired heart disease in children in developed countries. Although diverse immune aberrance was reported, a global understanding of immune responses underlying acute KD was lacking. Based on single-cell sequencing, we profiled peripheral blood mononuclear cells from patients with acute KD before and after intravenous immunoglobulin therapy and from healthy controls. Most differentially expressed genes were derived from monocytes, with upregulation of immunoglobulin receptors, complement and receptors and downregulation of MHC class II receptors before therapy. The percentage of B cells was significantly increased before therapy and rapidly returned to normal after therapy. There was also an increased abundance of B-cell receptors with IGHA and IGHG after therapy, accompanied by massive oligoclonal expansion. The percentage of CD8 T cells was remarkably decreased during acute KD, especially the subset of effector memory CD8 T cells. All lymphocyte compartments were characterized by underexpressed interferon response pathways before therapy. The identification of unique innate and adaptive immune responses suggests potential mechanisms underlying pathogenesis and progression of KD.