CRP and Sacroiliac arthritis: Selected variables were IBP, HLA B27, CRP, SpA features, positive sacroiliitis on radiography, SPBME ≥2, WPBME ≥2, erosion, fat metaplasia, backfill, sclerosis ≥1, and the different associations of the SP/WPBME ≥2 with the Tw1CL.