1. Axial Spondyloarthritis (SpA): Representative Values of Sensitivity and Specificity for Several Tests with the Resulting LRs *LR+ = sensitivity/(1 – specificity); LR- = (1 – sensitivity)/specificity. †As enthesitis, dactylitis, uveitis, peripheral arthritis, psoriasis and IBD may not be present at disease onset but may develop later, it is recommended to ignore a negative test result of these tests in an early state of possible axial SpA. The LR- of parameters, which should be ignored, are shown in brackets. ‡The figures for sensitivity and specificity of HLA-B27 refer to a European Caucasian population. In European Caucasian patients with psoriasis or IBD, a sensitivity of 50%, a specificity of 90%, an LR+ of 5.0 and an LR- of 0.56 for HLA-B27 should be applied. In other ethnic populations, sensitivity and specificity of HLA-B27 may be different, resulting in different LR+ and LR-. Adapted from Rudwaleit M, Feldtkeller E, Sieper J. Ann Rheum Dis 2006;65:1251-2. ParameterSensitivity (%)Specificity (%)LR+LR- Inflammatory back pain75763.10.33 Heel pain (enthesitis)37893.4(0.71)† Peripheral arthritis40904.0(0.67)† Dactylitis18964.5(0.85)† Iritis or anterior uveitis22977.3(0.80)† Psoriasis10962.5(0.94)† Inflammatory bowel disease (IBD)4994.0(0.97)† Family history of axial SpA, psoriasis, reactive arthritis, IBD, or anterior uveitis 32956.40.72 Good response to NSAIDs77855.10.27 Elevated C-reactive protein or erythrocyte sedimentation rate 50802.50.63 HLA-B27‡90 9.00.11 Sacroiliitis on MRI90 9.00.11

2. Post-test Probability of Axial SpA on the Resulting LR Product for a Pretest Probability of 5% Adapted from Rudwaleit M, Feldtkeller E, Sieper J Ann Rheum Dis 2006;65:1251-2.

3. Coronal T1-weighted MR image shows subchondral fatty marrow changes (arrows). There is irregularity of sacroiliac joint. Coronal fat-saturated contrast- enhanced T1-weighted image shows small foci of enhancement at inferior sacroiliac joint arrows). Adapted from Bredella et al. AJR 2006;187:1420-6.

4. Spondylitis anterior in T6/7 and T7/8 and spondylitis posterior in T8/9 as seen in the STIR MRI sequence. Inflammation is seen as a spot in the vertebra (arrows). Adapted from Baraliakos et al. Ann Rheum Dis 2005;64:730-4.

5. Assessment of Spinal Lesions at 12 Weeks and at Two Years After Placebo/infliximab or Open-label Infliximab Treatment Adapted from Sieper et al. Rheumatology 2005;44:1525-30.

6. Placebo (n=78)Infliximab (n=201) Baseline n=77n=200 Mean (standard deviation)6.21 (7.95)5.91 (6.58) Median (interquartile range)4.00 (0.00, 9.50)3.57 (0.25, 9.00) Change from baseline to week 24 n=72n=195 Mean (standard deviation)0.38 (3.97)-4.44 (6.16) Median (interquartile range)0.25 (-2.50, 2.75)-2.00 (-8.00, 0.00) Change from baseline to week 102 n=60n=161 Mean (standard deviation)-4.89 (6.85)-4.87 (6.42) Median (interquartile range)-1.00 (-8.75, 0.00)-2.00 (-8.50, 0.00) ASSERT Results: AS MRI Spinal Score for Activity Adapted from Braun et al. EULAR 2007, abstract OP0044.

7. Histological and Immunohistochemical Evaluation in Spondyloarthropathy in Infliximab Treated Patients Study population I (n=10 infliximab) BaselineWeek 12P value Lining layer Synovial lining layer thickness1.5 (1 to 2)1 (1 to 1.5)0.015  V  3 lining 0 (0 to 3)1 (0 to 2.5)0.516 VCAM-1 lining3 (1.5 to 3)1.5 (1 to 3)0.034 ICAM-1 lining3 (1.5 to 3)2.5 (1.5 to 3)0.238 E-selectin lining0 (0 to 1.5)0 (0 to 0.5)0.180 CD163 lining2 (0 to 2.5)1.5 (0 to 3)0.864 Blood vessels Vascularity1.75 (1 to 3)1.25 (1 to 2.5)0.339 von Willebrand factor3 (0 to 3)1.5 (1 to 3)0.170 CD1463 (1 to 3)1.5 (0 to 3)0.105  V  3 endothelial 1 (0 to 2.5)0 (0 to 1.5)0.058 VCAM-1 endothelial0 (0 to 1.5) 0.180 ICAM-1 endothelial3 (0 to 3)2.5 (1 to 3)1.000 E-selectin endothelial1.5 (0 to 3)1 (0 to 2.5)0.230 Sublining layer VCAM-1 sublining1 (0 to 3)0 (0 to 2.5)0.173 ICAM-1 sublining3 (0 to 3)1.25 (0.5 to 3)0.141 E-selectin sublining2 (0.5 to 3)1 (0 to 2)0.034 Degree of inflammatory cell infiltration1.75 (0.5 to 2.5)0.75 (0 to 2)0.018 Number of neutrophils0.5 (0 to 3)0 (0 to 0)0.041 Number of lymphoid aggregates1.75 (0 to 3)0.5 (0 to 3)0.073 CD32 (0 to 3)0.5 (0 to 2)0.026 CD41.5 (0 to 3)0.5 (0 to 2)0.076 CD82 (0 to 2.5)1 (0 to 1)0.061 CD191 (0 to 3)0 (0 to 1)0.059 CD201.5 (0 to 3)1 (0 to 3)0.750 Number of plasma cells0.5 (0 to 3)0 (0 to 3)0.258 CD381.5 (0 to 3) 0.516 CD1381 (0 to 3) 0.680 CD682 (0 to 3)1 (0.5 to 2)0.034 CD1631.25 (0 to 3)0.5 (0 to 2.5)0.469 CD83 (+/-)4/90/9NC CD1a (+/-)6/92/90.125 Adapted from Kruitoff et al. Ann Rheum Dis 2005;64:529-36. Semiquantitative histological and immunohistochemical scores are given as median (range). The immunohistochemical markers CD83 and CD1a (sublining layer) were scored as present (+) or absent (-). The P value was calculated for study population I using the paired Wilcoxon signed rank test for the semiquantitative scores and the McNemor test for the dichotomous scores. (NC = not calculable)

8. Clinical Response of Spondylarthritis Patients Treated for 12 Weeks* *Values are the median (range). † P<0.05 vs. week 0. Adapted from Kruitoff et al. Arthritis Rheum 2006;54:1795-804. Infliximab (n=20)Etanercept (n=20)Control (n=12) Week 0Week 12Week 0Week 12Week 0Week 12 Patient global assessment, 100-mm VAS 69 (17-100)15 (0-73)†73 (18-100)14 (0-69)†79 (24-90)67 (47-98) Physician global assessment, 100-mm VAS 64 (35-89)15 (8-75)†54 (36-89)15 (1-59)†43 (20-94)62 (27-89) Patient pain assessment, 100-mm VAS 69 (14-100)16.5 (1-86)†69 (17-99)12 (0-80)†68.5 (9-90)73 (37-97)† Swollen joint count 7 (0-24)1 (0-7)†3 (1-19)1 (0-10)†2 (1-11)2 (1-24) Tender joint count 10 (1-20)0 (0-6) †5 (0-23)1 (0-13) †2 (0-6)3 (0-20) C-reactive protein, mg/dL 2.3 (1.0-7.4)0.3 (0-7.9)†1.0 (0-15.0)0.3 (0-3.4)†3.1 (0.2-15.8)1.8 (0.1-7.4) Erythrocyte sedimentation rate, mm/hour 24 (11-101)6 (1-34)†16 (1-86)8 (1-39)†21 (5-107)17 (4-101)

9. IMPACT 2: Mean Changes in Modified Sharp/van der Heijde Erosion and Joint Space Narrowing (JSN) Scores to Week 54 Adapted from Van der Heijde et al. Arthritis Rheum 2007;56(8):2698-707.

10. Course of Radiographic Deterioration: Infliximab vs. Conventional Treatment in the OASIS Cohort Adapted from Baraliakos et al. Reumatology 2007;46:1450–3.

11. Adapted from Vastesaeger et al. SpA Congress 2006, Ghent, Belgium. ASPECT trial poster P21.