Baraliakos, X; Heldmann, F; Callhoff, J; Listing, J; Appelboom, T; Brandt, J; Van den Bosch, F; Breban, M; Burmester, GR; Dougados, M; Emery, P; Gaston, H; Grunke, M; Van Der Horst-Bruinsma, I E; Landewé, R; Leirisalo-Repo, M; Sieper, J; De Vlam, K; Pappas, D; Kiltz,, U