Detection of circulating FcɛR2/CD23+ monocytes in patients with rheumatic diseases

Abstract

SUMMARY Recently, in vitro studies have demonstrated that expression of FcɛR2/CD23 on normal monocytes can be specifically induced by IL-4. In order to investigate the interaction of IL-4 and monocytes in rheumatic diseases, flow cytometry studies were performed. Elevated numbers of circulating FcɛR2/ CD23+ monocytes were detected in patients with progressive systemic sclerosis (PSS) as compared with controls, in addition, supernatants derived from phytohaemagglutinin-stimulated peripheral blood mononuclear cells of PSS patients contained high activity to induce FcɛR2/CD23 on CDI4+ monocytes. An increased frequency of FcɛR2/CD23+ monocytes was also observed in rheumatoid arthritis, and sequential studies in patients with systemic lupus erythematosus showed a close relationship between FcɛR2/CD23+ monocytes and disease activity. It is suggested that IL-4 has an important role in the pathogenesis of PSS by activating monocytes, and might also contribute to monocyte activation in other rheumatic diseases.