Characteristics of the study group*
| Patients | ||||
|---|---|---|---|---|
| Characteristic | HLA-B27+ healthy siblings (n=71) | All patients (n=188) | Patients with AS (n=120) | Non-AS patients (n=67) |
| *AS, ankylosing spondylitis; non-AS, undifferentiated spondyloarthropathy (n=51), psoriatic arthritis (n=12), inflammatory bowel disease associated arthritis (n=4), and Reiter's syndrome (n=1); 95% CI, 95% confidence interval; NA, not applicable. | ||||
| *Radiographic sacroiliitis of at least bilateral grade II or unilateral grade III. The number of patients evaluated in each group was 69, 187, 120, and 67 respectively; †Percentages are the sum of the percentages for Crohn's disease and ulcerative colitis. | ||||
| Sex ratio, (male/female) | 0.65 | 1.14 | 1.5 | 0.4 |
| Age, mean (95% CI) | 42 (38.3 to 44.9) | 42 (40.4 to 44.4) | 44 (41.5 to 46.5) | 40 (36.1 to 42.9) |
| Duration of disease, mean (95% CI) | NA | 18 (16.4 to 20) | 22 (19.6 to 24.2) | 12 (9.3 to 14.1) |
| HLA-B27 positivity, No (%) | 71 (100) | 185 (98) | 120 (100) | 65 (96) |
| Axial symptoms, No (%) | ||||
| All | 0 (0) | 180 (96) | 120 (100) | 60 (88) |
| Back or buttock inflammatory pain | 0 (0) | 179 (95) | 119 (99) | 60 (88) |
| Sacroiliitis (pelvic x ray)* | 0/69 (0) | 120/187 (64) | 120 (100) | 0 (0) |
| Peripheral enthesitis, No (%) | 3 (4) | 109 (58) | 61 (51) | 50 (74) |
| Peripheral arthritis, No (%) | 1 (1) | 90 (48) | 59 (49) | 22 (32) |
| Uveitis, No (%) | 0 (0) | 57 (30) | 51 (42) | 6 (9) |
| Psoriasis, No (%) | 3 (4) | 35 (19) | 22 (18) | 13 (19) |
| Crohn/ulcerative colitis, No (%)† | 0/1 (1) | 3/5 (4) | 2/3 (4) | 1/2 (4) |