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

Abstract

SUMMARY To investigate the regulation of Fcγ receptor (FcγR) expression on circulating phagocytes in Kawasaki disease (KD), we analysed the expressions of FcγRI, 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 patients had a significantly higher level of FcγRI expression on neutrophils, but not on monocytes, than the BI, VI and HC patients. FcγRII expression on neutrophils was significantly higher in KD, BI and VI than HC, but there was no significant difference in FcγRII expression among KD, BI and VI. FcγRIII expression on neutrophils in KD was significantly lower than in VI and HC, but was higher on monocytes. A kinetic analysis of FcγR expression in KD demonstrated the expression of FcγRI and II on neutrophils to decline, but no remarkable change was observed in the monocytes, from the subacute phase through the convalescent phase. In addition, FcγRIII expression on neutrophils increased, while FcγRIII expression on monocytes decreased during the time course of KD. FcγR expression in the acute phase of KD is thus characterized by markedly increased expression of FcγRI on neutrophils, followed by a subsequent decrease, and decreased expression of FcγRIII on neutrophils and increased expression of FcγRIII on monocytes followed by a reverse kinetics during the clinical course. These findings are thus considered to reflect the functional up-regulation of neutrophils and monocytes in KD.