Table 2.
Clinical characteristics of patients diagnosed with nr-axSpA
| Northwest Africa (N = 26) | South Africa (N = 7) | |
|---|---|---|
| HLA-B27 status, n (%) | ||
| Positive | 9 (34.6) | 6 (85.7) |
| Negative | 5 (19.2) | 1 (14.3) |
| Results not available | 12 (46.2) | 0 (0.0) |
| Time from IBP to SpA diagnosis (SD), years | 2.5 (2.4) | 14.5 (20.5) |
| n | 6 | 2 |
| Family history of SpA, n (%) | ||
| Yes | 8 (30.8) | 1 (14.3) |
| No | 18 (69.2) | 4 (57.1) |
| Results not available | 0 (0.0) | 2 (28.6) |
| Sacroiliitis diagnosis (unilateral up to grade 2), n (%) | ||
| Diagnosed with X-rays | 18 (69.2) | 1 (14.3) |
| Diagnosed with an MRI | 4 (15.4) | 0 (0.0) |
| Not diagnosed | 4 (15.4) | 6 (85.7) |
| Results unavailable | 0 (0.0) | 0 (0.0) |
| Highest sacroiliitis grade, n (%) | ||
| Grade 0 | 1 (3.9) | 0 (0.0) |
| Grade I | 11 (42.3) | 0 (0.0) |
| Grade II | 9 (34.6) | 1 (14.3) |
| Grade III | 1 (3.9) | 0 (0.0) |
| Grade IV | 0 (0.0) | 0 (0.0) |
| Missing | 4 | 6 |
| NSAID response, n (%) | ||
| Positive | 19 (73.1) | 3 (42.9) |
| Negative | 4 (15.4) | 3 (42.9) |
| Results not available | 3 (11.5) | 1 (14.3) |
| Most recent CRP value, mean (SD) | 18.1 (30.5) | 7.1 (9.6) |
| n | 23 | 5 |
| Most recent CRP levels, n (%) | ||
| Not elevated (< 3.5 mg/l) | 7 (26.9) | 3 (42.9) |
| Elevated (= 3.5 mg/l) | 16 (61.5) | 2 (28.6) |
| Results not available | 3 (11.5) | 2 (28.6) |
| Most recent ESR value, mean (SD) | 29.5 (32.1) | 5.2 (4.0) |
| Most recent ESR value, n (missing) | 24 (2) | 5 (2) |
| Most recent ESR levels, n (%) | ||
| Not elevated (< 28 mm/h) | 15 (57.7) | 5 (71.4) |
| Elevated (= 28 mm/h) | 9 (34.6) | 0 (0.0) |
| Results not available | 2 (7.7) | 2 (28.6) |
AS ankylosing spondylitis, CRP C-reactive protein, ESR erythrocyte sedimentation rate, HLA-B27 human leukocyte antigen B27, IBP inflammatory back pain, nr-axSpA nonradiographic axial spondyloarthritis, NSAID nonsteroidal anti-inflammatory drug, n/N number, SpA spondyloarthritis, SD standard deviation