Correlation between age and epinephrine (EPI) effects in patients with rheumatoid arthritis (RA) and healthy subjects. The age of the subjects was plotted against concentrations of the relative interferon (IFN)-γ in (a) healthy donors (HDs) and (b) patients with RA and of interleukin (IL)-10 in (c) HDs and (d) patients with RA after co-incubation of activated T cells with 10-5 M EPI for 48 hours. The baseline values of each HD and patient with RA were defined as 100%. (Concentrations are presented in Figure 1 legend.) The cytokine concentrations upon co-incubation with 10-5 M EPI are given as percentage of baseline values. p, the p value; r, the respective correlation coefficient.