Chemokines and angiogenesis.

Chemokines mediate the ingress of leukocytes, including neutrophils and monocytes, into the inflamed synovium. Among the four known chemokine families, C-X-C and C-C chemokines seem to be of outstanding importance in this process. Angiogenesis, the formation of new vessels, is also important in the pathogenesis of rheumatoid arthritis. In this review, the authors discuss the role of the most important chemokines in the pathogenesis of rheumatoid synovitis. The most relevant angiogenic factors and angiogenesis inhibitors involved in rheumatoid arthritis are also discussed. Because certain chemokines may also play a role in neovascularization, chemokines and the process of angiogenesis are described in this context as well. Apart from discussing the pathogenic role of these factors, the authors also review the important relevance of chemokines and angiogenesis for therapeutic intervention.