Risk for HLA-B27 positive FDR to have AS by the modified New York criteria at baseline, or to have axSpA at follow-up
| Study | Total number of HLA-B27(+) FDR (mean age ±SD) | Risk for all FDR to have AS (mNY+) at baseline or axSpA at follow-up (95% CI) (males+females) | Risk for all male FDR to have AS (mNY+) at baseline or axSpA at follow-up (95% CI) (males) | Risk for all female FDR to have AS (mNY+) at baseline or axSpA at follow-up (95% CI) (females) |
| Baseline (1985) -Multicase families excluded | 308 (27.1±8.4) | 14/308 (4.5%) (2.2 to 6.9%) | 7/135 (5.2%) (1.5 to 8.9%) | 7/173 (4.0%) (1.1 to 6.9%) |
| Baseline (1985) -Multicase families included | 318 (27.6±8.3) | 24/318 (7.5%) (4.6 to 10.4%) | 11/139 (7.9%) (3.4 to 12.4%) | 13/179 (7.3%) (3.5 to 11.1%) |
| Follow-up 35 years later -Multicase families excluded | 171 (61.8±8.6) | 42/171 (24.6%) (18.1 to 31.0%) | 17/71 (23.9%)* (14.0 to 33.8%) | 25/100 (25.0%)* (16.5 to 33.5%) |
| Follow-up 35 years later -Multicase families included | 177 (62.1±8.5) | 48/177 (27.1%) (20.6 to 33.7%) | 19/73 (26.0%)† (15.9 to 36.1%) | 29/104 (27.9%)† (19.3 to 36.5%) |
*p = 0.87.
†p= 0.78 (no significant gender-specific difference in occurrence of axSpA among HLA-B27(+) FDR).
AS, ankylosing spondylitis; axSpA, axial spondyloarthritis ; FDR, first-degree relatives.