Chemokines and their receptors in rheumatoid arthritis: future targets?

Rheumatoid arthritis (RA) is a chronic inflammatory disease leading to joint destruction (1). In RA, migration of leukocytes into the synovial tissue (ST) occurs. These leukocytes and other cells in the ST, particularly RA ST fibroblasts, produce mediators of inflammation, including chemokines (1). Chemokines, currently numbering more than 50, are chemotactic cytokines that are important in recruitment of leukocytes and angiogenesis. They exert chemotactic activity toward a variety of cell types (2–7). Some chemokines, particularly CXC chemokines containing the ELR motif, are angiogenic. The last few years have seen a rapid development of studies aimed at targeting proinflammatory chemokines or their receptors in RA and animal models of RA (8,9). This review summarizes many of the important developments in this field. Based on the number of recently published studies, it is likely that the next few years will bring several new preclinical and clinical trials targeting chemokines.