Cytokine secretion by Tregs in 5 AA patients and 3 healthy donors. (A) Amounts of IFN-γ, TNF-α, and IL-17 secreted by Tregs were significantly higher (P = .02, P = .02 and P = .01, respectively) in 5 AA patients than in 4 healthy donors, whereas the amount of secreted IL-4 was not significantly different between the 2. (B) An example of intracellular staining of AA and healthy donor Tregs for cytokines after 4 hours of stimulation with phorbol myristate acetate and ionomycin in the presence of brefeldin A. The amount of intracellular IFN-γ (IFN-g), TNF-α (TNF-a), and IL-17 was markedly higher in patient Tregs than in healthy donor Tregs.