Comparison of Non-radiographic Axial Spondyloarthritis and Ankylosing Spondyltis from a Single Rheumatology Hospital in Morocco

Background: According to the new classification criteria developed by The Assessment of SpondyloArthritis International Society, patients with axial spondyloarthritis (axSpA) can be classified in 2 subgroups: Patients with radiographic axial spondyloarthritis: ankylosing spondylitis patients (AS) and those with non-radiographic axial spondyloarthritis (nr-axSpA). Objective: The aim of the present study is to describe and discuss the differences and similarities between the two subgroups. Patients and Methods: A cross-sectional study was conducted in a single rheumatology hospital in Morocco. These included patients diagnosed as having axial spondyloarthritis according to ASAS criteria 2010, during a period of 6 years. The AS and the nr-axSpA subgroups were compared for the various axSpA-related variables. Results: Of the 277 patients with a diagnosis of axial SpA who were included in this study, 160 had AS and 117 had nr-axSpA. AS and nr-ax-SpA shared a similar age at diagnosis, similar prevalence of low back pain, lumbar stiffness, extra-articular manifestations, BASDAI and BASFI. In the multivariate analysis, AS patients were mainly male with cervical stiffness, enthesitis, coxitis and high level of ESR (erythrocyte sedimentation rate). The females generally had a family history of SpA and arthritis and were associated to the nr-axSpA form in the univariate analysis. Conclusion: This was the first study to characterise patients with AS and nr-axSpA in Morocco. Consistent with other studies published, this study showed that patients with nr-axSpA and patients with AS shared a comparable degree of disease burden.