Patient characteristics. All data are median (range) unless otherwise indicated.
| Age, yrs | 60 (31–78) |
| Female | 71% |
| Disease duration, yrs | 4.5 (1–20) |
| IgM rheumatoid factor-positive | 71% |
| Swollen joint count, 0–28 | 6 (1–20) |
| Tender joint count, 0–28 | 5 (1–26) |
| CRP, mg/l | 9 (3–117) |
| DAS28-CRP3 | 4.2 (3.5–7.1) |
| HAQ score | 1.13 (0–1.88) |
| No. previous DMARD | 2.5 (1–5) |
| Methotrexate dose, mg/week | 18.8 (7.5–25) |
The healthy control was a 37-year-old male. CRP: Serum C-reactive protein; DAS: Disease Activity Score; HAQ: Health Assessment Questionnaire; DMARD: disease-modifying antirheumatic drugs.