Evaluation of the T helper 17 axis in ankylosing spondylitis.

To evaluate the T helper 17 (Th17) axis and its relation to tumor necrosis factor (TNF) alpha blockage and disease activity in ankylosing spondylitis (AS). The study included 127 AS patients (100M/27F) and 38 (27M/11F) controls. Spinal mobility was assessed by the bath ankylosing spondylitis metrology index (BASMI). Patients were also evaluated with the bath ankylosing spondylitis functional (BASFI) and bath ankylosing spondylitis disease activity index. Cytokines including IL-6, IL-12, TGF-β, IL-17A, and IL-23 were measured in serum sample using commercially available ELISA kits. Cytokines including IL-6, IL-12, TGF-β, IL-17, and IL-23 were significantly higher in the AS patients than the controls (P < 0.05). The Th-17-related cytokines were not different between patients treated with anti-TNF and conventional therapies (P > 0.05). Cytokines were also similar between patients with active and inactive disease (P > 0.05). On correlation analysis, IL-17 was correlated with IL-23 and IL-12 (P < 0.05) and IL-23 showed correlations with IL-12 and BASMI (P < 0.05). We found serum levels of Th-17-related cytokines to be significantly increased in the sera of AS patients. Disease activity and treatment type did not affect the level of these cytokines.