Table 1. Baseline characteristics.
| Placebo (n = 78) | 5 mg/kg infliximab (n = 201) | |
| Men, no. (%) | 68 (87.2%) | 157 (78.1%) |
| Age, years | ||
| Mean (SD) | 40.3 (9.4) | 39.6 (10.6) |
| Disease duration, years | ||
| N | 76 | 201 |
| Mean (SD) | 11.9 (8.0) | 10.1 (8.7) |
| Median (range) | 13.2 (0.3, 31.6) | 7.7 (0.3, 41.1) |
| HLA-B27 positive | ||
| N | 78 | 200 |
| No. (%) | 69 (88.5%) | 173 (86.5%) |
| Inflammation (average morning stiffness on a visual analogue scale 0–10 cm) | ||
| N | 78 | 201 |
| Mean (SD) | 6.9 (1.9) | 6.9 (2.3) |
| Median (range) | 7.0 (0.8, 10.0) | 7.3 (0.2, 10.0) |
| Bone mineral density | ||
| Total spine bone mineral density (g/cm2) | ||
| N | 73 | 189 |
| Mean (SD) | 1.09 (0.25) | 1.01 (0.18) |
| Median (range) | 1.02 (0.77, 2.01) | 1.01 (0.63, 1.64) |
| Spine T scores | ||
| N | 72 | 186 |
| Mean (SD) | −0.28 (2.00) | −0.96 (1.45) |
| Median (range) | −0.75 (−2.70, 7.40) | −0.95 (−4.20, 3.60) |
| Total hip bone mineral density (g/cm2) | ||
| N | 74 | 192 |
| Mean (SD) | 0.95 (0.14) | 0.92 (0.14) |
| Median (range) | 0.92 (0.69, 1.36) | 0.91 (0.59, 1.38) |
| Hip T scores | ||
| N | 74 | 190 |
| Mean (SD) | −0.62 (0.91) | −0.75 (0.97) |
| Median (range) | −0.70 (−2.20, 2.10) | −0.80 (−3.30, 2.30) |
| Hip Z scores | ||
| N | 74 | 190 |
| Mean (SD) | −0.42 (0.90) | −0.54 (0.95) |
| Median (range) | −0.60 (−2.00, 2.24) | −0.60 (−3.00, 2.50) |
| Syndesmophytes | ||
| Patients with syndesmophytes* | 54 (71.1%) | 122 (61.0%) |
| Regions with syndesmophytes† | 486 (27.6%) | 908 (19.3%) |
| Biomarker levels | ||
| IL-6 (pg/ml) | ||
| N | 67 | 187 |
| No. (%) with values ⩾LLOQ | 32 (47.8%) | 105 (56.1%) |
| Mean (SD) | 11.4 (17.2) | 13.2 (20.0) |
| Median (range) | 3.1 (3.1, 119.1) | 7.7 (3.1, 174.6) |
| VEGF (pg/ml) | ||
| N | 75 | 193 |
| No. (%) with values ⩾LLOQ | 75 (100%) | 191 (99.0%) |
| Mean (SD) | 556.2 (385.6) | 520.4 (361.5) |
| Median (range) | 473.5 (67.8, 2353.7) | 421.5 (29.8, 2067.5) |
| TGF-β (pg/ml) | ||
| N | 75 | 192 |
| No. (%) with values ⩾LLOQ | 75 (100%) | 192 (100%) |
| Mean (SD) | 45.9 (11.5) | 46.8 (11.7) |
| Median (range) | 46.7 (9.4, 85.9) | 48.1 (6.0, 90.3) |
| Osteocalcin (ng/ml) | ||
| N | 73 | 197 |
| No. (%) with values ⩾LLOQ | 71 (97.3%) | 197 (100%) |
| Mean (SD) | 17.4 (8.7) | 18.4 (9.9) |
| Median (range) | 15.8 (1.7, 41.3) | 16.9 (4.8, 73.5) |
| BAP (U/l) | ||
| N | 73 | 197 |
| No. (%) with values ⩾LLOQ | 73 (100%) | 197 (100%) |
| Mean (SD) | 27.6 (10.1) | 26.7 (9.2) |
| Median (range) | 25.4 (8.5, 63.5) | 25.0 (10.9, 62.1) |
| CTX (ng/ml) | ||
| N | 72 | 198 |
| No. (%) with values ⩾LLOQ | 66 (90.4%) | 184 (93.4%) |
| Mean (SD) | 0.39 (0.24) | 0.39 (0.25) |
| Median (range) | 0.34 (0.1, 1.6) | 0.33 (0.1, 1.8) |
BAP, bone alkaline phosphatase; CTX, C-terminal cross-linking telopeptide of type I collagen; HLA, human leucocyte antigen; IL-6, interleukin-6; LLOQ, lower limit of quantification; TGF-β, transforming growth factor β; VEGF, vascular endothelial growth factor.
*Defined as a patient with at least one vertebral region that received an mSASSS score of ⩾2. See Methods for description of mSASSS scoring system.
†Defined as any region that received an mSASSS score of ⩾2.