Introduction

The new term axial spondyloarthritis (SpA) covers both patients with ankylosing spondylitis (AS) according to the modified New York criteria, for which the presence of radiographic sacroiliitis is mandatory, and patients with non-radiographic axial disease. The latter group can be defined either by the presence of active inflammatory sacroiliitis on MRI or by the presence of clinical parameters in addition to a positive human leucocyte antigen-B27 testing. This classification according to the new ‘Assessment in SpondyloArthritis international Society’ (ASAS) criteria1 allows an earlier diagnosis of these patients before chronic changes visible by x-ray examination have already occurred. The question of remission should therefore be discussed for the whole group of patients with axial SpA, especially because remission might be reached more easily if patients are treated earlier.

Remission can be divided into (1) clinical remission; (2) absence of objective inflammation such as a raised C-reactive protein (CRP) or active inflammation on MRI shown on a short τ inversion recovery (STIR) sequence; (3) reaching normal function; (4) prevention of (further) structural damage and (5) remission of extra-articular manifestations/associated diseases such as uveitis, psoriasis or inflammatory bowel disease (IBD).