Baseline characteristics of the patients.
| Characteristics | All Patients, n = 82 | Patients with Infusion Reactions, n = 14 | Patients without Infusion Reactions, n = 68 |
|---|---|---|---|
| Female, n (%) | 59 (72) | 12 (86) | 47 (69) |
| Diagnosis, n (%) | |||
| JIA | 70 (85) | 14 (100) | 56 (81) |
| Persistent oligoarthritis/extended oligoarthritis | 30 | 4 | 26 |
| Polyarthritis (RF-negative) | 24 | 7 | 17 |
| Polyarthritis (RF-positive) | 1 | 0 | 1 |
| Enthesitis-related arthritis | 3 | 0 | 3 |
| Psoriatic arthritis | 1 | 1 | 0 |
| Systemic arthritis | 5 | 1 | 4 |
| Undifferentiated arthritis | 6 | 1 | 5 |
| Ocular inflammatory disease | 10 (12) | 0 | 10 (15) |
| Other inflammatory disease | 2 (2) | 0 | 2 (3) |
| Unclassified systemic inflammatory disease | 1 | 1 | |
| Takayasu arteritis | 1 | 1 | |
| Comorbid conditions, n (%) | 16 (20) | 3 (21) | 13 (19) |
| Genetic diseases (e.g., trisomy 21, Williams-Beuren syndrome) | 6 | 1 | 5 |
| Autoimmune diseases (e.g., linear SSc, Crohn disease) | 4 | 0 | 4 |
| Other (e.g., osteochondritis dissecans, attention deficit disorder) | 6 | 2 | 4 |
| Indication for IFX (%) | |||
| Arthritis | 49 (60) | 12 (86) | 37 (54) |
| Uveitis | 16 (20) | 0 | 16 (24) |
| Arthritis and uveitis | 13 (16) | 2 (14) | 11 (16) |
| Other | 4 (5) | 0 | 4 (6) |
| Crohn disease and JIA | 1 | 1 | |
| Systemic JIA | 1 | 1 | |
| Unclassified systemic inflammatory disease | 1 | 1 | |
| Takayasu arteritis | 1 | 1 | |
| Comedication, n (%) | |||
| MTX | 67 (82) | 11 (79) | 56 (82) |
| Leflunomide | 8 (10) | 2 (14) | 6 (9) |
| MTX, then leflunomide | 4 (5) | 0 | 4 (6) |
| MTX, then azathioprine | 0 | 1 (7) | 0 |
| Sulfasalazine | 1 (1) | 0 | 1 (1) |
| Azathioprine | 1 (1) | 0 | 1 (1) |
| Previous biologicals, n (%) | 21 (26) | 3 (21) | 18 (26) |
| Age at IFX start, yrs, mean ± SD | 10.1 ± 3.9 | 8.2 ± 4.2 | 10.5 ± 3.7 |
| Range | 2.3–17.0 | 2.3–16.9 | 3.7–17.0 |
| Disease duration at IFX start, yrs, mean ± SD | 3.9 ± 3.3 | 2.9 ± 2.2 | 4.1 ± 3.5 |
| Range | 0.2–14.7 | 0.7–7.0 | 0.2–14.7 |
| Followup during study period, wks, mean ± SD | 169 ± 136.6 | 173 ± 175.2 | 168.3 ± 128.8 |
| Range | 3–560 | 18–560 | 0–545.4 |
| Number of infusions, mean ± SD | 30 ± 20 | 30 ± 29 | 0 |
| Range | 2–114 | 6–114 | |
| Dose of IFX, mg/kg/dose, mean ± SD | 6.2 ± 1.5 | 5.5 ± 1.7* | 6.3 ± 1.5 |
| Range | 3.5–10.4 | 3.5–8.5 | 3.5–10.4 |
| Infusion interval of IFX, wks, mean ± SD | 5.2 ± 1.3 | 5.0 ± 1.3* | 5.3 ± 1.4 |
| Range | 2.2–15** | 2.9 ± 7.0 | 2.2–15** |
↵* Calculated from beginning of IFX treatment to first infusion reaction.
↵** Usually we discontinued treatment after maximum infusion interval of 12 weeks. The long interval of 15 weeks was due to retardation caused by viral illness. IFX: infliximab; RF: rheumatoid factor; SSc: systemic sclerosis; MTX: methotrexate.