IL15RA and Arthritis: The analysis identified that presence of at least one ACPA reactivity (hazard ratio [HR] 8.0; 95% CI: 2.9, 22), ultrasound-detected tenosynovitis (HR 3.4; 95% CI: 2.0, 6.0), IL-6 levels (HR 1.5; 95% CI: 1.2, 1.8) and IL-15 receptor α (IL-15Rα) levels (HR 0.6; 95% CI: 0.4, 0.9) are significant independent predictors for arthritis progression in a prediction model (Harrell’s C 0.76 [s.