Table 1.
Demographic and clinical characteristics of patients and healthy controls
| HC | RA | PsA | SLE | |
|---|---|---|---|---|
| Number | 120 | 40 | 120 | 40 |
| Gender female/male | 56/64 | 33/7 | 62/58 | 36/4 |
| Age (years) | 41 (18–62) | 57 (38–70) | 52 (19–70) | 55 (25–72) |
| Disease Activity Score/Index | ||||
| DAS44* | n.a. | 4·7 (2·7–7·3) | 4·9 (2·1–8·1) | n.a. |
| SLEDAI‐2K † | n.a. | n.a. | n.a. | 4 (0–82) |
| Treatments ‡ | ||||
| DMARD, n (%) | n.a. | 14 (35) | 40 (34) | 16 (40) |
| CS, n (%) | n.a. | 4 (10) | 8 (7) | 7 (17·5) |
| DMARD+CS, n (%) | n.a. | 19 (47·5) | 27 (23) | 16 (40) |
| None, n (%) | n.a. | 3 (7·5) | 45 (37·5) | 1 (2·5) |
Data expressed as median (range) if not specified otherwise. HC = healthy controls; RA = rheumatoid arthritis; PsA = psoriatic arthritis; SLE = systemic lupus erythematosus. *DAS44 (range = 0–10) is a continuous measure consisting of four variables: the Ritchie articular index (RAI), a 44 swollen joint count, erythrocyte sedimentation rate (ESR) and a general health (GH) assessment measured on a visual analogue scale. Level of disease activity: low (DAS ≤ 2·4), moderate (2·4 < DAS ≤ 3·7), high (DAS > 3·7), remission (DAS <1·6) 19. †SLEDAI‐2K = SLE Disease Activity Index 2000. SLEDAI‐2K ≥ 4 indicate active disease 20. ‡Concomitant treatments at the time of blood collection: DMARD = disease modifying anti‐rheumatic drugs (methotrexate, sulphasalazine, hydroxicloroquine, azathioprine, cyclosporin; CS = corticosteroids (prednisone); none = no treatment; n.a. = not applicable.