Expression of chemokines and matrix metalloproteinases in early rheumatoidarthritis

Objective. To compare macrophage infiltration and expression of chemokines and matrix metalloproteinases (MMPs) in synovial tissue between patients wi th early and long-standing rheumatoid arthritis (RA). Methods. Knee synovial biopsies were taken from 22 patients with early (<1 yr) and 22 patients with long-standing (>5 yr) RA and immunostained with an tibodies specific for CD68; macrophage inflammatory protein (MIP)-1 alpha a nd monocyte chemoattractant protein (MCP)-1; MMP-1 and -3 and the tissue in hibitors of metalloproteinases (TIMP)-1 and -2. Immunostaining was quantifi ed using a colour video image analysis system. Results. CD68+ macrophage infiltration and the expression of MIP-1 alpha, M CP-1, MMP-1, MMP-3, TIMP-1, and TIMP-2 were observed in synovial tissue of patients with early RA. In long-standing RA, there was a further increase i n CD68+ macrophage infiltration and MIP-1 alpha expression in the synovial lining layer. CD68 expression correlated with MIP-1 alpha (R=0.39, P=0.01), but not with MCP-1 expression. Conclusion. Macrophage accumulation, and the expression of chemokines and M MPs in synovial tissue occur in early RA. Targeting chemokines which play a role in the migration of macrophages into the joints may be of therapeutic benefit in RA patients.