New tools for diagnosing spondyloarthropathy

Ankylosing spondylitis (AS) in its established and early forms accounts for more than 5% of all cases of chronic low back pain. Attention has focused recently on decreasing the time from symptom onset to the diagnosis of AS, which currently ranges from five to 10 years. An earlier diagnosis would lead to improved management, in particular thanks to the recent introduction and continuing development of biotherapies, such as TNFα antagonists, and new imaging techniques, including Doppler ultrasonography and magnetic resonance imaging have proved capable of detecting early signs of AS. Biotherapies not only improve the symptoms, but may also slow or halt the progression of the inflammatory lesions before the development of radiographic changes. Current criteria for AS (New York, Amor, and ESSG) are classification criteria that provide useful diagnostic orientation in clinical practice but have inadequate sensitivity for the diagnosis of recent-onset AS. Several groups have been working on means of improving the early diagnosis of AS. An algorithm for the early diagnosis of axial AS developed by Rudwaleit et al. needs to be confirmed by prospective studies. The Assessment of SpondyloArthritis international Society (ASAS) has just issued new diagnostic criteria for AS that performed well in a large cohort of patients with recent-onset low back pain.