BSR and BHPR guideline for the treatment of axial spondyloarthritis (including ankylosing spondylitis) with biologics.

Axial SpA (axSpA) is a chronic inflammatory condition predominantly involving the spine and sacroiliac joints (SIJ), with or without extra-spinal manifestations including peripheral arthritis, enthesitis, iritis, psoriasis and IBD. Individuals with axSpA experience significant pain, stiffness and lack of function, which translates into important health care costs and increased mortality. AxSpA can be classified into two subgroups: radiographic axSpA, commonly referred to as AS, and non-radiographic axSpA (nr-axSpA). The primary difference between these two subgroups is the presence or absence of defined structural changes in the SIJ as detected on plain radiography. A diagnosis of AS can be made according to the modified New York criteria when radiographs show at least grade 2 sacroiliitis bilaterally or grade 3 unilaterally, in the presence of appropriate clinical symptoms [1]. In contrast, SIJ radiographs may be completely normal in nr-axSpA. The radiographic changes of AS may take 8 10 years to manifest, with a progression rate from nr-axSpA to AS of 12% every 2 years [2], although some patients with nr-axSpA never develop AS. Disease progression is predicted most strongly