CRP and Sacroiliac arthritis: Given the varying disease course across patients, studies have assessed factors associated with progression from non-radiographic axSpA to radiographic axSpA: active sacroiliitis on magnetic resonance imaging (MRI), smoking, human leukocyte antigen (HLA)-B27 positivity, and elevated C-reactive protein (CRP) are suggested as factors associated with progression to radiographic axSpA [10, 11, 14, 15].