Page 27 - SPONDYLOARTHRITIS IN COLOMBIA -

INTRODUCTION
Spondyloarthritis (SpA) comprises a heterogeneous group of diseases that share common clinical, radiological and genetic characteristics. SpA includes among others ankylosing spondylitis (AS), undifferentiated SpA (uSpA), reactive arthritis (ReA), psoriatic arthritis (PsA) and SpA associated with inflammatory bowel disease (IBD) 1. Several sets of classification criteria have been developed for clinical and epidemiological studies. The European Spondylarthropathy Study Group (ESSG) 2 and the Amor 3 were the first criteria aimed at classifying patients along the whole disease spectrum. However, these two criteria sets do not perform as well in early recognition of the disease 4 5 and do not distinguish between axial and peripheral disease in separate sets6. Recently, the Assessment of SpondyloArthritis international Society (ASAS) criteria were developed for the classification of patients with SpA and for better distinguishing between patients with axial-SpA (axSpA) 7 and peripheral-SpA (pSpA) 8.
Diagnostic criteria for SpA are lacking but diagnostic algorithms have been developed. The adaptation of the ‘Berlin algorithm’, might be a useful tool in clinical practice 9. In clinical setting, a flexible approach is often applied: complete clinical data are rarely obtained, important clinical questions could be missed, and the rheumatologist, rather than a fixed protocol, determines whether additional clinical testing (imaging, HLA-B27) is necessary. Consequently, applying classification criteria including such “on request only” tests may suffer from many missing data and yield different results in clinical practice than in validation cohorts.
The ASAS-SpA criteria 6,7 were recently applied in different clinical settings. The full criteria were tested in a cohort with long-standing SpA 10, and the pSpA criteria were tested in a particular cohort of patients with recent-onset arthritis 11, both European cohorts. However, to our knowledge the
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