Modulation of interferon (IFN)-γ and interleukin (IL)-10 synthesis of activated T cells by catecholamines in healthy donors (HDs) (n = 16, white bars) and patients with rheumatoid arthritis (RA) (n = 16, gray bars). The concentrations of IFN-γ upon co-incubation with (a) epinephrine (EPI) and (b) norepinephrine (NE) and of IL-10 upon co-incubation with (c) EPI and (d) NE were determined in the culture supernatant by means of enzyme-linked immunosorbent assay after T-cell stimulation for 48 hours. The baseline values of each RA patient and HD were defined as 100%, and the cytokine concentrations upon co-incubation with catecholamines were expressed as percentage of baseline values. *p < 0.001 and ¶p < 0.05 denote significant differences in cytokine production of patients with RA or HDs compared with the control values. P values indicate significant differences between the catecholamine effects of patients with RA and HDs, respectively. PROP, propranolol.