Clinical description of the ankylosing spondylitis cases stratified according to their HLA-B27 genotype and allele status
| Variable | HLA-B27 genotypes | p Value | ||
|---|---|---|---|---|
| B27 +/+ cases (n = 31) | B27 +/− cases (n = 220) | B27−/− cases (n = 19) | ||
| The statistical significances of differences in categorical and continuous variables were calculated using χ2 analysis (comparing B27 antigen positive and negative cases) and the quantitative transmission disequilibrium test (total association within families), respectively. All the HLA-B27 positive ankylosing spondylitis cases were used in the data analysis. | ||||
| AAU, acute anterior uveitis; BASDAI, Bath ankylosing spondylitis disease activity index; BASFI, Bath ankylosing spondylitis functional index; IBD, inflammatory bowel disease. | ||||
| AAU (n (%)) | 19 (61%) | 104 (47%) | 3 (16%) | 0.004 |
| IBD (n (%)) | 0 | 15 (7%) | 3 (16%) | NS |
| Psoriasis (n (%)) | 2 (6%) | 4 (2%) | 0 | NS |
| Peripheral arthritis (n (%)) | 21 (68%) | 176 (80%) | 13 (68%) | NS |
| BASDAI (mean (SD)) | 4.5 (1.6) | 5.4 (1.8) | 5.1 (2.4) | 0.05 |
| BASFI (mean (SD)) | 3.5 (2.6) | 4.0 (2.3) | 4.4 (2.3) | NS |
| Age of symptom onset (mean (SD)) | 25.9 (7.3) | 26.8 (8.1) | 35.7 (11.2) | p<0.0001 |
| (range) | (15 to 44) | (14 to 55) | (18 to 54) | |
| Age at diagnosis (mean (SD)) | 32.5 (9.1) | 35.1 (9.7) | 43.4 (10.0) | p<0.0001 |
| (range) | (21 to 52) | (18 to 73) | (25 to 55) | |
| Diagnostic delay (mean (SD)) | 6.1 (6.6) | 8.4 (10.9) | 6.9 (6.8) | NS |
| (range) | (0 to 24) | (0 to 53) | (0 to 26) | |
| Disease duration (mean (SD)) | 23.8 (10.2) | 23.9 (10.3) | 18.3 (12.0) | NS |
| (range) | (8 to 48) | (3 to 60) | (3 to 49) | |