Regulation of the expression of Fc gamma receptor on circulating neutrophils and monocytes in Kawasaki disease

To investigate the regulation of Fc gamma receptor (Fc gamma R) expression on circulating phagocytes in Kawasaki disease (KD), we analysed the express ions of Fc gamma RI, II and III on neutrophils and monocytes in 20 patients with KD, 10 with a bacterial infection (BI), 10 with a viral infection (VI ), and 10 healthy controls (HC) using flow cytometric analysis. The KD pati ents had a significantly higher level of Fc gamma RI expression on neutroph ils, but not on monocytes, than the BI, VI and HC patients. Fc gamma RII ex pression on neutrophils was significantly higher in KD, BI and VI than HC, but there was no significant difference in Fc gamma RII expression among KD , BI and VI. Fc gamma RIII expression on neutrophils in KD was significantl y lower than in VI and HC, but was higher on monocytes. A kinetic analysis of Fc gamma R expression in KD demonstrated the expression of Fc gamma RI a nd II on neutrophils to decline, but no remarkable change was observed in t he monocytes, from the subacute phase through the convalescent phase. In ad dition, Fc gamma RIII expression on neutrophils increased, while Fc gamma R III expression on monocytes decreased during the time course of KD. Fc gamm a R expression in the acute phase of KD is thus characterized by markedly i ncreased expression of Fc gamma RI on neutrophils, followed by a subsequent decrease, and decreased expression of Fc gamma RIII on neutrophils and inc reased expression of Fc gamma RIII on monocytes followed by a reverse kinet ics during the clinical course. These findings are thus considered to refle ct the functional up-regulation of neutrophils and monocytes in KD.