Table 5.
Clinical characteristics and HLA-B27 test results of patients with nonradiographic axial spondyloarthritis across geographic regions
| Africa (n = 33) | Europe (n = 88) | Asia (n = 140) | p Value | |
|---|---|---|---|---|
| Laboratory-confirmed SpA (HLA-B27) | 0.062 | |||
| Positive, n (%) | 15 (45.45 %) | 56 (63.64 %) | 61 (43.57 %) | |
| Negative, n (%) | 6 (18.18 %) | 10 (11.36 %) | 37 (26.43 %) | |
| Results not available, n (%) | 12 (36.36 %) | 22 (25.00 %) | 42 (30.00 %) | |
| Laboratory-confirmed SpA (excluding missing) (HLA-B27) | 0.019 | |||
| Positive, n (%) | 15 (71.43 %) | 56 (84.85 %) | 61 (62.24 %) | |
| Negative, n (%) | 6 (28.57 %) | 10 (15.15 %) | 37 (37.76 %) | |
| Family history of SpA | 0.231 | |||
| Yes, n (%) | 9 (27.27 %) | 18 (20.45 %) | 43 (30.71 %) | |
| No, n (%) | 22 (66.67 %) | 67 (76.14 %) | 86 (61.43 %) | |
| Results not available, n (%) | 2 (6.06 %) | 3 (3.41 %) | 11 (7.86 %) | |
| Family history of SpA (excluding missing) | 0.125 | |||
| Yes, n (%) | 9 (29.03 %) | 18 (21.18 %) | 43 (33.33 %) | |
| No, n (%) | 22 (70.97 %) | 67 (78.82 %) | 86 (66.67 %) | |
| NSAID response | 0.264 | |||
| Positive, n (%) | 22 (66.67 %) | 64 (72.73 %) | 93 (66.43 %) | |
| Negative, n (%) | 7 (21.21 %) | 22 (25.00 %) | 42 (30.00 %) | |
| Results not available, n (%) | 4 (12.12 %) | 2 (2.27 %) | 5 (3.57 %) | |
| Most recent CRP level | 0.214 | |||
| Not elevated (<3.5 mg/L), n (%) | 10 (30.30 %) | 21 (23.86 %) | 37 (26.43 %) | |
| Elevated (≥3.5 mg/L), n (%) | 18 (54.55 %) | 55 (62.50 %) | 80 (57.14 %) | |
| Results not available, n (%) | 5 (15.15 %) | 12 (13.64 %) | 23 (16.43 %) | |
| Most recent CRP level (excluding missing) | 0.104 | |||
| Not elevated (<3.5 mg/L), n (%) | 10 (35.71 %) | 21 (27.63 %) | 37 (31.62 %) | |
| Elevated (≥3.5 mg/L), n (%) | 18 (64.29 %) | 55 (72.37 %) | 80 (68.38 %) | |
| Most recent ESR level | <0.001 | |||
| Not elevated (<28 mm/h), n (%) | 20 (60.61 %) | 66 (75.00 %) | 69 (49.29 %) | |
| Elevated (≥28 mm/h), n (%) | 9 (27.27 %) | 17 (19.32 %) | 66 (47.14 %) | |
| Results not available, n (%) | 4 (12.12 %) | 5 (5.68 %) | 5 (3.57 %) | |
| Most recent ESR level (excluding missing) | <0.001 | |||
| Not elevated (<28 mm/h), n (%) | 20 (68.97 %) | 66 (79.52 %) | 69 (51.11 %) | |
| Elevated (≥28 mm/h), n (%) | 9 (31.03 %) | 17 (20.48 %) | 66 (48.89 %) |
Abbreviations: CRP C-reactive protein, ESR erythrocyte sedimentation rate, HLA-B27 human leukocyte antigen B27, NSAID nonsteroidal anti-inflammatory drug, SpA spondyloarthritis
The p values represent the omnibus statistical comparison of percentages (or means) across regions based on the chi-square values