Serum levels of IL-17 in patients and controls. Patients with the highest baseline levels had higher levels of IL-23, TNF-α and IFN-γ. (a) Serum levels of IL-17 in patients at baseline and follow-up in patients and levels in controls (medians 97.4, 48.0 and 3.3 pg/ml respectively). The dotted line denotes the upper 25% of IL-17 levels (above 165 pg/ml). The patients with the highest baseline levels of IL-17 (>165) pg/ml had higher levels of IL-23 as shown in (b), TNF-α (c) and IFN-γ (d) vs. those with IL-17 levels < 165. Boxes limits show 25th to 75th percentile and median values are marked inside the boxes.