Demographic characteristics, clinical and laboratory features at baseline, concomitant MTX treatments, and characteristics of ETN treatment and discontinuation in JIA patients who flare and those who did not flare in the 12 months of followup after ETN withdrawal, after attaining remission. Data are n (%) calculated by Fisher’s exact test, or median (IQR) using the Mann-Whitney U test.
| Characteristics | All Patients, n = 110 | Flare, n = 66 | No Flare, n = 44 | p |
|---|---|---|---|---|
| Sex, female | 77 (70) | 41 (62.1) | 36 (81.8) | 0.034 |
| Sex, male | 33 (30) | 25 (37.9) | 8 (18.2) | |
| Age at disease onset, yrs | 3.6 (1.8–8.5) | 3.7 (2.0–8.7) | 3.1 (1.7–8.4) | 0.60 |
| Disease duration at diagnosis. mos | 2.3 (1.5–4.1) | 2.3 (1.5–3.3) | 2.5 (1.5–5.0) | 0.44 |
| oJIA | 57 (51.8) | 33 (50) | 24 (54.5) | 0.70 |
| pJIA | 53 (48.2) | 33 (50) | 20 (45.5) | |
| ANA-positive (≥ 1:160) | 71 (64.5) | 48 (72.7) | 23 (52.3) | 0.047 |
| ANA-negative | 39 (35.5) | 18 (27.3) | 21 (47.3) | |
| CRP at baseline, mg/dl | 1.0 (0.3–2.3) | 1.2 (0.4–3.2) | 0.4 (0.2–1.5) | 0.012 |
| No. patients with CRP > ULN | 66 (60) | 46 (69.7) | 20 (45.5) | 0.017 |
| No. active joints at baseline | 6 (3–9) | 5.0 (3.0–7.3) | 6.0 (3.0–10.5) | 0.40 |
| Joint involved at baseline | ||||
| Cervical spine | 10 (9.1) | 6 (9.1) | 4 (9.1) | 1.0 |
| Temporomandibular | 10 (9.1) | 5 (7.6) | 5 (11.4) | 0.52 |
| Elbow | 25 (22.7) | 18 (27.3) | 7 (15.9) | 0.25 |
| Wrist | 39 (35.5) | 21 (31.8) | 18 (40.9) | 0.42 |
| Metacarpophalangeal | 10 (9.1) | 4 (6.1) | 6 (13.6) | 0.19 |
| Proximal interphalangeal | 59 (53.6) | 34 (51.5) | 25 (56.8) | 0.70 |
| Hip | 15 (13.6) | 6 (9.1) | 9 (20.5) | 0.10 |
| Knee | 82 (74.5) | 48 (72.7) | 34 (77.3) | 0.66 |
| Ankle | 79 (71.8) | 50 (75.8) | 29 (65.9) | 0.29 |
| Disease duration at baseline, mos | 9.1 (4.0–25.3) | 8.1 (3.7–21.0) | 9.7 (5.3–39.4) | 0.07 |
| Concomitant MTX at baseline | 106 (96.4) | 63 (95.5) | 43 (97.7) | 0.65 |
| Concomitant MTX at ETN stop | 87 (79.1) | 50 (75.8) | 37 (84.1) | 0.34 |
| Time from ETN start to CID, mos | 4.5 (2.2–7.3) | 4.8 (2.2–6.8) | 4.2 (2.9–9.3) | 0.61 |
| Time from CID to ETN withdrawal, mos | 14.6 (11.1–21.3) | 14.6 (11.9–21.9) | 14.7 (10.4–20.7) | 0.40 |
| ETN treatment duration | 22.2 (18.4–27.9) | 22.2 (18.4–28.2) | 21.9 (18.5–27.1) | 0.85 |
| ETN abrupt withdrawal | 82 (74.5) | 52 (78.8) | 30 (68.2) | 0.27 |
| ETN gradual reduction | 28 (25.5) | 14 (21.2) | 14 (31.8) |
ANA: antinuclear antibody; ULN: upper limit of normal; CRP: C-reactive protein; MTX: methotrexate; ETN: etanercept; JIA: juvenile idiopathic arthritis; IQR: interquartile range; CID: clinically inactive disease; oJIA: oligoarticular JIA; pJIA: polyarticular JIA.