Deyab G, et al. - This study aimed to compare endothelial function (EF) in patients with inflammatory arthritis (IA), and to investigate the impacts of methotrexate (MTX) monotherapy and antitumor necrosis factor (anti-TNF) treatment with or without MTX comedication (anti-TNF ± MTX) on EF. The current study showed that the treatment with MTX and anti-TNF ± MTX was related to a relatively fast improvement of EF in IA patients with endothelial dysfunction (ED), independent of change in disease activity. Therefore, modes of action other than the anti-inflammatory effect may contribute to the EF improvement. The EF improvement was more pronounced in the MTX group than in the anti-TNF ± MTX group after 6 months.