Inflammatory cytokines, endothelial markers and adhesion molecules in rheumatoid arthritis: effect of intensive anti-inflammatory treatment

Tumour necrosis factor alpha (TNF-α) and interlekin-6 (IL-6) are key inflammatory cytokines in the pathogenesis of rheumatoid arthritis (RA), a disease also associated with endothelial perturbation and increased serum levels of adhesion molecules. As relationships between these processes and molecules are unclear, we tested the hypotheses (a) that TNF-α and IL-6 are linked to endothelial activation/damage and levels of soluble adhesion molecules, and (b) that intensive anti-inflammatory treatment improves levels of these indices. We recruited 66 patients with RA, 48 community controls (CC), and 25 disease controls (DC). Plasma TNF-α and IL-6 were compared to markers of vascular biology (vWF, sE-sel), soluble adhesion molecules (sICAM, sVCAM) and routine inflammatory markers (CRP and ESR). Blood was obtained at baseline and at 1 week and again 4 weeks after anti-inflammatory treatment in a subgroup of 29 patients with RA. With the exception of sE-selectin, RA patients had increased levels of all plasma markers compared to the HCs, whilst levels in the DCs were largely intermediate between RA and the CCs. Within the RA group, sEsel correlated with both CRP and ESR whilst TNF-α correlated with sVCAM (all r > 0.32, P < 0.01). After 1 week of combined anti-inflammatory therapy, only CRP, ESR, sEsel and sVCAM were significantly reduced (all P < 0.05). In RA, endothelial activation (as sEsel) correlates with classical markers of inflammation and is reduced by intensive anti-inflammatory medications.