Increased Circulating Th17 Cells, Serum IL-17A, and IL-23 in Takayasu Arteritis

Introduction.Th17,γδT, NK, and NKT cells in peripheral blood and serum IL-17 and IL-23 in Takayasu arteritis (TA) were measured and correlated with disease activity.Methods.Th17 (anti-CD3APC, CD4PECy7, and IL-17PE), NKT, NK (anti-CD3APC, CD56FITC), andγδT (anti-CD3FITC andγδTCRAPC) cells were enumerated by flow cytometry in peripheral blood of 30 patients with TA (ACR1990 criteria) and 20 healthy controls, serum IL-17 and IL-23 measured by ELISA. Relation with disease activity (NIH criteria, ITAS2010) was analyzed (using nonparametric tests, median with interquartile range).Results.Mean age of patients was33.47±11.78years (25 females); mean symptom duration was7.1±5.3years. 13 were not on immunosuppressants; 12 were active (ITAS2010 ≥ 4). The percentage of Th17 cells was significantly expanded in TA (patients 2.1 (1.5–3.2) versus controls 0.75 (0.32–1.2);p<0.0001) with no differences in other cell populations. Serum IL-17 and IL-23 (pg/mL) in patients (6.2 (4.6–8.5) and 15 (14.9–26.5), resp.) were significantly higher (p<0.001) than controls (3.9 (3.9–7.3) and undetectable median value, resp.). Subgroup analysis revealed no correlation of Th17 cells, serum IL-17, and IL-23 with disease activity or medications, nor any significant difference before and after medication.Conclusions.There is significant expansion of Th17 cells and elevated serum IL-17 and IL-23 levels in TA patients compared to healthy controls.