Table 1.
Clinical and laboratory characteristics of patients at baseline and following treatment with infliximab 5 mg/kg every 6 weeks (time points at 16 weeks and 56 weeks) and after continuing infliximab treatment 3 mg/kg every 8 weeks (time point at 2 years).
| Characteristics | Baseline | 16 weeks | 56 weeks | 2 years |
|---|---|---|---|---|
| Number of men/women | 14/5 | 14/5 | 14/4 | 13/2 |
| Age (mean years ± SD) | 39 ± 9 | |||
| AS symptom duration (mean years ± SD) | 13.1 ± 8.9 | |||
| AS diagnosis duration (mean years ± SD) | 6.9 ± 7.0 | |||
| Peripheral arthritis, number (%) of patients | 8 (42%) | 2 (10%) | 0 (0%) | 0 (0%) |
| Uveitis, present or in history, number (%) of patients | 7 (37%) | 0 (0%) | 0 (0%) | 0 (0%) |
| MTX dose mg/week; median (IQR) | 7.5 (7.5–9.4) | 7.5 (7.5–7.5) | 7.5 (7.5–7.5) | 7.5 (7.5–7.5) |
| Concomitant NSAID use, number (%) of patients | 18 (95%) | 10 (53%)* | 9 (50%)* | 7 (47%)* |
| Concomitant regular use of analgesics, number (%) of patients | 7 (37%) | 7 (37%) | 7 (38%) | 3 (20%) |
| Bath AS scores; median (IQR) | ||||
| BASDAI | 6.5 (5.4–8.0) | 2.9 (1.0–3.7)*** | 2.1 (0.6–3.6)*** | 3.2 (0.4–4.1)** |
| BASFI | 4.8 (3.8–6.4) | 2.7 (0.7–3.9)*** | 1.8 (0.2–3.9)*** | |
| BASMI | 3.0 (2.0–4.3) | 1.0 (1.0–3.0)* | 1.4 (0–3.0)** | |
| BASG-1 | 7.5 (6.0–8.3) | 3.3 (1.1–4.3)*** | 1.1 (0–4.2)*** | |
| BASG-2 | 7.2 (6.3–8.8) | 4.9 (2.5–6.5)** | 1.6 (0.2–3.5)*** | |
| ESR mm/h; median (IQR) | 23 (14–37) | 6 (2–10)** | 5 (2–8)*** | 7 (4–12)** |
| CRP mg/L; median (IQR)# | 27 (8–45) | 8 (8–8)** | 8 (8–8)** | 8 (5–8)** |
| Hemoglobin g/L; median (IQR) | 135 (132–139) | 141 (136–156)* | 143 (138–154)* | 153 (142–157)** |
| Disease Activity Score—DAS28; median (IQR) | 3.03 (2.73–3.76) | 1.74 (0.84–2.50)** | 1.9 (0.98–2.11)* | 1.80 (1.44–1.87)* |
| MRI SPARCC score; median (IQR) | 3 (1.5–6.0) | 0 (0–2.25)** | 0 (0)** | — |
| SF-36 health score; median (IQR) | ||||
| PCS— physical total score | 29.2 (23.1–33.2) | 38.9 (32.8–50.9)** | 45.4 (33.5–54.9)** | — |
| MCS—mental total score | 37.3 (26.7–48.6) | 53.3 (32.6–58.9)ns | 53.5 (46.1–56.1)ns | — |
| Anti-infliximab antibodies, number (%) of patients | 0/19 (0%) | NA | NA | 4/15 (27%)* |
BASDAI: Bath AS Disease Activity Index; BASFI: Bath AS Function Index; BASMI: Bath AS Metrology Index; BASG1: Bath AS Patients Global score (last 2 weeks); BASG2: Bath AS Patients Global score (last 6 months); CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; HAQ: Health Assessment Questionnaire Disability Index; DAS28: Disease Activity Score; NA: not analyzed.
#Lowest detection limit for CRP <8 mg/L.
Comparisons between continuous measures at different time points as compared to baseline values were calculated employing the Wilcoxon signed rank test for paired samples and comparisons between the groups regarding percentage were calculated using Fisher's exact test. The level of significance is expressed as follows: *P < 0.05, **P ≤ 0.005, ***P ≤ 0.0005, ns: not significant.