RELATIONSHIP BETWEEN INTERLEUKIN-8 AND NEUTROPHIL ADHESION MOLECULES IN RHEUMATOID-ARTHRITIS

To evaluate the role of interleukin-8 (IL-8) on the activation of neut rophils in rheumatoid arthritis (RA), we measured IL-8 and the adhesio n molecules, L-selectin (CD62L), CD11b and CD18, on neutrophils in pai red peripheral blood and synovial fluid of RA patients, Synovial fluid IL-8 levels were significantly increased compared to peripheral blood . L-selectin was split off and CD11b and CD18 were upregulated on neut rophils in the synovial fluid. A positive correlation occurred between the IL-8 concentration and CD18 or CD11b densities on neutrophils in the synovial fluid (r=0.75, P<0.005 and r=0.60, P<0.05, respectively). Peripheral blood neutrophils of the patients were desensitised with I L-8 in vivo, as shown by the significantly lower L-selectin shedding a fter in vitro IL-8 stimulation: 1.6 times decrease for patients vs 3.2 for controls (P<0.05). In conclusion, these results add further evide nce for the role of IL-8 in the activation of neutrophils in RA.