Figure 2  .

Correlation of the density of β₂ adrenergic receptors (β2R) with disease activity. In patients with rheumatoid arthritis (RA) and systemic sclerosis (SSc) a significant negative correlation could be seen between systemic activity scores and the density of β2R on CD19+ lymphocytes. Correlation between β2R and disease activity just missed the significance level in the group with SLE: (A) β2R v the total disease activity score (TAI) in patients with RA; (B) β2R v the SLE activity measure (SLAM) in patients with SLE; (C) β2R v the SSc score (SSS) in patients with SSc. Correlation between β2R and the values obtained by the different scoring systems used in this study (TAI, SLAM, SSS) was calculated by the Pearson product moment correlation test.