Clinical characteristics of patients with polyarticular juvenile idiopathic arthritis (pJIA) and controls with rheumatoid arthritis (RA). Values are no. (%) unless stated otherwise.
| Characteristic | pJIA, n = 43 | RA, n = 59 | p |
|---|---|---|---|
| Age, yrs, median (IQR) | 23.0 (20.0–30.8) | 46.0 (32.8–51.0) | < 0.01 |
| Sex, female/male | 35/8 | 52/7 | 0.35 |
| Disease duration, yrs, median (IQR) | 13.0 (6.3–21.8) | 11 (8.0–15.8) | 0.20 |
| RF-positive | 23 (54) | 47 (79) | 0.01 |
| ACPA-positive | 16/31 (52) | 46/58 (79) | 0.01 |
| ANA-positive | 11 (26) | 10/58 (17) | 0.31 |
| Previous use of steroids | 26 (61) | 56 (95) | < 0.01 |
| DMARD | 41 (95) | 58 (98) | 0.40 |
| No. DMARD/patient, mean ± SD | 1.9 ± 1.4 | 3.0 ± 1.7 | < 0.01 |
| Use of biological agents | 30 (70) | 40 (68) | 0.83 |
| No. biological agents/patient | 1.2 ± 1.3 | 1.5 ± 1.5 | 0.29 |
| Surgery | 11 (26) | 16 (27) | 0.86 |
| Prosthetic surgery | 5 (12) | 5 (8) | 0.60 |
| Tender joint count, mean ± | SD 3.1 ± 4.6 | 6.4 ± 6.4 | 0.01 |
| Swollen joint count, mean ± | SD 2.7 ± 4.3 | 5.1 ± 4.5 | 0.01 |
| ESR, mean ± SD | 20.3 ± 21.9 | 22.5 ± 23.0 | 0.62 |
| CRP, mean ± SD (no. available; N < 5) | 9.1 ± 18.3 (39) | 19.4 ± 31.6 (50) | 0.08 |
RF: rheumatoid factor; ACPA: anticitrullinated protein antibody; ANA: antinuclear antibody; DMARD: disease-modifying antirheumatic drugs; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; N: reference value; IQR: interquartile range.