Table 2.
Patient characteristics of children with clinically inactive juvenile idiopathic arthritis with and without synovial thickening on MRI
| Variable | Total n=52 |
Group 1 JAMRIS ≥1 n=18 |
Group 2 JAMRIS = 0 n=34 |
P-value | |
|---|---|---|---|---|---|
| Female gender, n (%) | 33 (63.5) | 10 (19.2) | 23 (44.2) | 0.389 | |
| Age, years | 13.3 (10.4–15.7) | 10.7 (9.3–13.6) | 14.4 (12.1–16.3) | 0.008 | |
| Waiting period, daysa | 35 (27.5–53.0) | 36 (23.75–45.5) | 35 (28.0–54.0) | 0.855 | |
| JIA parameters | |||||
| Age at disease onset | 9.4 (6.0–12.3) | 7.9 (5.7–10.9) | 10.6 (6.1–13.3) | 0.260 | |
| Disease duration (subjective)b | 3.9 (2.4–6.6) | 3.1 (1.8–7.0) | 4.3 (2.9–6.5) | 0.178 | |
| Disease duration (objective)c | 2.8 (1.1–5.6) | 2.1 (1.0–5.3) | 3.2 (1.7–5.8) | 0.237 | |
| Duration of inactivity (days) | 198 (34–470.5) | 192.5 (28–275) | 226 (34–571) | 0.256 | |
| Uveitis in patient history, n (%) | 3 (5.8) | 0 (0.0) | 3 (8.8) | ||
| Disease activity parameters | |||||
| CHAQ | 0.3 (0.0–0.8) | 0.3 (0.0–0.8) | 0.3 (0.0–0.9) | 0.707 | |
| JADAS-10 | 1.4 (0.3–3.2) | 1.0 (0.3–4.1) | 1.5 (0.4–2.9) | 0.400 | |
| Physician’s VAS | 1.0 (0.0–4.0) | 0.0 (0.0–3.3) | 2.0 (0.0–4.5) | ||
| Patient’s VAS | |||||
| - Pain | 12.0 (0.0–32.0) | 9.0 (0.0–45.0) | 14.5 (0.0–25.3) | 0.751 | |
| - Global | 5.0 (0.0–22.0) | 5.0 (0.0–49.0) | 6.5 (0.0–20.5) | 0.980 | |
| JAMRISd | 0.0 (0.0–1.0) | 1.0 (1.0–3.3) | 0 (0.0) | ||
| Laboratory results | |||||
| ANA | Positive, n (%) | 7 (13.5) | 3 (16.7) | 4 (11.8) | |
| Negative, n (%) | 45 (86.5) | 15 (83) | 30 (78.9) | ||
| HLA-B27 | Positive, n (%) | 8 (15.4) | 4 (22.2) | 4 (11.8) | |
| Negative, n (%) | 38 (73.1) | 13 (72.2) | 25 (65.8) | ||
| IgM RF | Positive, n (%) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Negative, n (%) | 49 (94.2) | 16 (88.9) | 33 (97.1) | ||
| Anti-CCP | Positive, n (%) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Negative, n (%) | 50 (96.2) | 16 (88.9) | 34 (100) | ||
| Medication use | |||||
| None | 7 (13.5) | 2 (11.1) | 5 (14.7) | ||
| NSAID | 3 (5.8) | 0 (0.0) | 3 (8.8) | ||
| Methotrexatee | 31 (59.6) | 11 (61.1) | 20 (58.8) | ||
| Sulfasalazinee | 5 (9.6) | 3 (16.7) | 2 (5.9) | ||
| Etanercept | 2 (3.8) | 2 (11.1) | 0 (0.0) | ||
| Etanercept + Methotrexated | 4 (7.7) | 0 (0.0) | 4 (11.8) | ||
ANA antinuclear antibody, Anti-CCP anti-cyclic citrullinated peptides, CHAQ childhood health assessment questionnaire, HLA-B27 human leukocyte antigen B-27, IgM RF immunoglobulin M rheumatoid factor, JADAS juvenile arthritis disease activity score, JAMRIS juvenile arthritis MRI scoring system, JIA juvenile idiopathic arthritis, NSAID nonsteroidal anti-inflammatory drug, VAS visual analog scale
aNumber of days between the date of clinical assessment and the date of MRI
bNumber of years between disease onset as experienced by the patient/parents and date of the clinical assessment
cNumber of years between date of diagnosis and date of the clinical assessment
dJAMRIS ≥1 is defined as a synovial thickness ≥2 mm on at least one location in the knee
eSome children used an additional nonsteroidal anti-inflammatory drugs