IL1B and rheumatoid arthritis: In patients with axSpA but not patients with RA, we found higher frequencies of classic monocytes than in controls (median of 90.4 % versus 80.4 %, P < 0.05), higher frequencies of monocytes spontaneously producing IL-1beta and IL-1ra (P < 0.05), and a higher percentage of monocytes producing IL-1beta after MDP stimulation (P < 0.05).