The effects of intravenous immunoglobulin on the expression of IgGFc receptor and TLR4 in children with acute Kawasaki disease

Abstract

Objective To investigate the effects of the intravenous immunoglobulin (IVIG) on the expression of FcγR Ⅱ b and Toll-like receptor 4 (TLR4) in children with Kawasaki disease (KD).Methods 25 children with KD and 15 healthy controls were enrolled in this study.The levels of TLR4 expression on monocytes were assessed by flow cytometry.Real-time PCR was performed to detect the transcription levels of FcγR Ⅱ b,TLR4 signaling molecules(MyD88,TRAF-6,TAK1) and cytokines(IL-1β,IL-6,TNF-α) in monocytes.The concentrations of TNF-α in plasma was determined by enzyme-linked immunosorbent assay (ELISA).Results (1) Compared with healthy controls,the expression of TLR4 and the signaling molecules in the patients were significantly up-regulated but decreased after treatment with IVIG (P＜0.05).(2)The levels of FcγR Ⅱb expression from the patients were higher than those from healthy controls,and decreased after treatment with IVIG(P＜0.05).(3) The levels of cytokine factor expression such as IL-1β,IL-6 and TNF-α in the patients were found to be higher than those in healthy controls (P＜0.05) ; plasma concentrations of TNF-α were significantly elevated during acute KD (P＜0.05).(4)There were significantly correlations to follow between FcγR Ⅱb and the levels of cytokine,TLR4 expression in monocytes (P ＜0.05).Conclusion IVIG can up regulate FcγR Ⅱb expression and down regulate TLR4 expression which might inhibit the inflammatory response. Key words: Fc gamma receptors; Kawasaki disease; Toll-like receptor 4; Cytokine