Monocyte migration induced by supernatants of RA SCLs (RA6/1 and RA8/3) stimulated with 2 ng/ml TNF-α was assessed using mAbs, which can neutralize specific chemokines or chemokine receptors. Concentrations of mAbs were 10 μg/ml for MCP-1, IL-8, and IP-10, and 50 μg for anti-CCR5 mAb with 5 × 10 SRBC rosette negative cells. Migrating cells were stained with anti-CD-14 mAb, and migrating CD14cells were counted by flow cytometry. The mean and SEM were calculated from the results of three independent experiments. The paired Student test was used to assess statistical differences versus the result with control mAb.