suggested that multiple ACPA reactivities (≥2 vs 0–1) was a significant risk factor (odds ratio 2.1; 95% CI: 1.0, 4.4; P = 0.04) with a strong trend of prediction for arthritis development (HR: 1.7; 95% CI: 0.93, 3.16, P = 0.08) in the Risk-RA phase [ 23 ]; and we can in this study report a significant predictive value of presence of ACPA reactivity (≥1 vs 0) for arthritis (HR 8.0; 95% CI: 2.9, 22; P < 0.001).
It is also of interest that presence of SE alleles was significantly associated with arthritis progression, whereas exposure to cigarette smoking was not, although smoking showed a numerical trend for association with disease progression.
Presence of ≥1 ACPA reactivity, ultrasound-detected tenosynovitis, IL-6 levels and IL-15Rα levels were identified as significant independent predictors for arthritis progression ( Figs 3–4 ) and after utilizing Bonferroni adjustment, these predictors remained significant with the exception of IL-15Rα, which was borderline significant.