IL17A and rheumatoid arthritis: Here we monitored circulating levels of different IL-22+ Th cell subsets and measured plasma levels of IL-22, IL-17, and interferon (IFN)-γ in 60 patients with active RA following 12-week combination methotrexate (MTX) and leflunomide (LEF) therapy (MTX+LEF) and 20 healthy individuals.