The early disease stage in axial spondylarthritis: Results from the german spondyloarthritis inception cohort

Ankylosing spondylitis (AS) is diagnosed late, because radiographs of the sacroiliac joints often do not show definite sacroiliitis at the time of disease onset. The aim of this study was to investigate whether patients without definite radiographically defined sacroiliitis, referred to as nonradiographic axial spondylarthritis (SpA), are different from patients with AS with regard to clinical manifestations and disease activity measures. Moreover, we sought to identify determinants of the development of radiographic sacroiliitis.

In a cross-sectional analysis of 462 patients, we compared 226 patients with nonradiographic axial SpA (symptom duration