Background. Chemokines are involved in leucocyte recruitment into inflammatory sites, such as the synovial tissue of patients with rheumatoid arthritis (RA). The release of certain chemokines is augmented by pro-inflammatory cytokines, such as tumor necrosis factor (TNF). Infliximab, a monoclonal antibody against TNF that blocks the biological effects of TNF, is used in the treatment of chronic inflammatory diseases. The effect of blocking TNF activity on chemokines is not fully understood.
Aim. The aim of this study was to analyse the effects on chemokines and their receptors on peripheral mononuclear cells of anti-TNF treatment in RA-patients.
Material and methods. Twelve patients with established RA who began treatment with infliximab, and nine patients with early RA treated with traditional disease-modifying anti-rheumatic drugs, were followed clinically for 30 weeks and chemokine levels in blood samples and chemokine receptor expression on the surface of T-cells and monocytes analysed. Three SLE-patients, as a small control group of another inflammatory disease, and nine healthy subjects were also included in the study.
Result. CXCL10/IP-10 was significantly higher in RA-patients compared with healthy controls and decreased significantly two weeks after infliximab infusion. CCL2/MCP-1 and CCL4/MIP-1β decreased significantly after infliximab treatment although the concentrations were not significantly elevated at baseline compared with controls. There was an inverse correlation between the chemokine cleaving molecule dipeptidyl peptidase-IV/CD26 and CCL5/RANTES. Several chemokine receptors on T-cells were elevated in RA patients at inclusion into the study. The CCR2 expression on T-cells decreased significantly after infliximab treatment.
Conclusion. The chemokines CXCL10/IP-10, CCL2/MCP-1 and CCL4/MIP-1β, mainly targeting the Th1 immune response, decreased after treatment with anti-TNF suggesting a more pronounced effect onTh1 activity than on the Th2 mediated response. Several chemokine receptors on blood T-cells were elevated in RA-patients, suggesting that they may be involved in the recruitment of T-lymphocytes from the blood to affected tissues.
2013. Vol. 42, no 4, 260-265 p.