Enhanced expression of integrins and CD66b on peripheral blood neutrophilsand eosinophils in patients with rheumatoid arthritis, and the effect of glucocorticoids

The aim of this study was to elucidate signs of granulocyte activation by s tudying adhesion and phagocytosis receptors on peripheral blood granulocyte s from patients with rheumatoid arthritis (RA), and to observe the effect o f glucocorticoids. Analyses by flow cytometry showed elevation of the neutr ophil and eosinophil expression of the alpha- and beta-chains of the beta(2 )-integrin Mac-1 (CD11b/CD18) and of the CEA-gene family member 6 (CGM6, CD 66b), Expression of the adhesion receptor antigens CD11a, CD29, CD49d, CD49 f and CD44, and the Fc gamma receptors II and III, was unaffected. Treatmen t with low-dose prednisolone reduced the expression of CD11b on neutrophils and of CD11b, CD18 and CD66b on eosinophils to the same level as that foun d in healthy controls. Metyrapone treatment increased the surface expressio n of CD35 and CD49f on eosinophils, but did not affect surface expression o n neutrophils. Activation of blood granulocytes may be important for the in creased recruitment of neutrophils and eosinophils to the synovial cavity i n RA. Treatment with low doses of glucocorticoids in RA normalizes the enha nced expression of the studied adhesion molecules in eosinophils but has mi nor impact on neutrophil activation. Endogenous glucocorticoid production s eems to have minimal or no effect on the expression of adhesion and phagocy tosis receptors on circulating granulocytes.