Demographic and paraclinical characteristics of patients with oligoarticular and systemic JIA. All patients were RF-negative and HLA-B27–negative. P value indicates differences between oligoarticular and systemic JIA using Mann-Whitney U test. Values are median (IQR) unless otherwise specified.
| Characteristics | Oligoarticular JIA, n = 109 | Systemic JIA, n = 19 | p |
|---|---|---|---|
| Female/male (% females) | 79/30 (72) | 10/9 (53) | 0.030 |
| Age at disease onset, mos | 37 (21–85) | 71 (35–119) | 0.066 |
| Disease duration, mos | 11.5 (6–31) | 7 (4–20) | 0.264 |
| Active joints, n | 1 (1–2) | 3.5 (1–4.25) | 0.001 |
| ESR, mm/h | 10 (6–17) | 50 (27–65) | < 0.001 |
| CRP, mg/l | 5 (5–6.8) | 86.6 (16–130.2) | < 0.001 |
| WBC, × 109/l | 8.3 (6.45–9.8) | 14.4 (9.6–20.7) | < 0.001 |
| NEU, × 109/l, mean ± SD | 4.27 ± 2.13 | 12.53 ± 8.16 | < 0.001 |
| Thrombocytes, × 109/l | 349 (289–414) | 530 (414–691) | < 0.001 |
| Hb, mmol/l | 7.3 (6.7–7.6) | 6.2 (5.4–6.8) | < 0.001 |
| ANA-positive, n | 58/109 | 4/18 | 0.015 |
JIA: juvenile idiopathic arthritis; RF: rheumatoid factor; IQR: interquartile range; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; WBC: white blood cell count; NEU: neutrophils; Hb: hemoglobin; ANA: antinuclear antibodies.