A pilot study of endothelial dysfunction and aortic stiffness after interleukin-6 receptor inhibition in rheumatoid arthritis.

Interleukin (IL)-6 is a pleiotropic proinflammatory cytokine involved in the pathogenesis of both atherosclerosis and rheumatoid arthritis. The role of the IL-6/IL-6 receptor pathway in the documented acceleration of atherosclerosis in rheumatoid arthritis has not been examined. In a non-randomized prospective pilot study we asked whether endothelial dysfunction, defined as impaired flow mediated dilatation (FMD), and aortic stiffness, assessed by pulse wave velocity (PWV) improve after 3 and 6 monthly therapeutic infusions of the anti-IL-6 receptor antibody tocilizumab for active rheumatoid arthritis. We found that FMD increased from 3.3 ± 0.8 to 4.4 ± 1.2 to 5.2 ± 1.9% (p = 0.003), whereas PWV decreased from 8.2 ± 1.2 to 7.7 ± 1.3 to 7.0 ± 1.0m/s (p < 0.001). Whether these beneficial arterial changes are direct effects of the IL-6/IL-6 receptor pathway inhibition, maintained over time and translate into better clinical outcome warrants further studies.