The Role of CCL18 in Rheumatoid Arthritis Diseases

Rheumatoid Arthritis (RA) is a chronic auto-immune disease that mostly occurs in joint space with remarkably painful swelling. RA detail pathologies remain unclear, but several C-C motif chemokines factors and Interleukin have been identified as associated factors and correlated disease-associate activities (such as CCL2, CCL18, IL-6). Among these factors, increasing evidence indicates CCL18 could be an appropriate drug target, as it is highly correlated with disease-associated activities (DAS28) (elevated level of CCL18 in both patient serum and local synovial fluids). High-concentration CCL18 in synovial fluids has been reported to facilitate pro-inflammation factor production, finally resulting in painful swelling in joint space. In vivo studies showed significant drug efficiency with anti-TNF-a treatment (CCl18 suppression). Most current approved drugs target TNF, IL-6, or other factors, but do not target CCL18 directly or indirectly. From this perspective, CCL18 has been believed to be a new target for RA therapeutic drug development.