Modulation of interleukin (IL)-4 and tumour necrosis factor (TNF)-α synthesis of activated T cells by catecholamines in healthy donors (HDs) (IL-4: n = 6; TNF-α: n = 5, white bars) and patients with rheumatoid arthritis (RA) (IL-4: n = 5; TNF-α: n = 7, gray bars). The concentrations of IL-4 upon co-incubation with (a) epinephrine (EPI) and (b) norepinephrine (NE) and of TNF-α 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 HD and patient with RA were defined as 100%, and the cytokine concentrations upon co-incubation with catecholamines are given as percentage of baseline values. *p < 0.001 and ¶p < 0.05 as compared with values obtained upon stimulation in the presence of medium alone. P values indicate significant differences between the catecholamine effects of patients with RA and HDs, respectively. PROP, propranolol.