Influence of catecholamines on cytokine ratios and intracellular interferon (IFN)-γ expression in healthy donors (HDs) (white bars) and patients with rheumatoid arthritis (RA) (gray bars). The ratios between the raw cytokine values of (a) IFN-γ and interleukin (IL)-10 (n = 16) or (b) IFN-γ and IL-4 (HDs: n = 6; patients with RA: n = 5) were evaluated after stimulation of T cells for 48 hours with medium and 10-5 M epinephrine (EPI), respectively. Intracellular IFN-γ was determined in (c) CD4-positive and (d) CD8-positive T cells activated for 12 hours. The baseline values of IFN-γ-positive cells in the CD4 and CD8 T-cell populations of each RA patient and HD were defined as 100%, and the number of IFN-γ-positive cells upon co-incubation with catecholamines related to the baseline values of each HD and patient with RA. *p < 0.05 as compared with the values obtained upon control conditions. NE, norepinephrine; PROP, propranolol.