T2 mapping of the sacroiliac joints in patients with axial spondyloarthritis

To validate and refine two sets of candidate criteria for the classification/diagnosis of axial spondyloarthritis (SpA). All Assessment of SpondyloArthritis international Society (ASAS) members were invited to include consecutively new patients with chronic (> or =3 months) back pain of unknown origin that began before 45 years of age. The candidate criteria were first tested in the entire cohort of 649 patients from 25 centres, and then refined in a random selection of 40% of cases and thereafter validated in the remaining 60%. Upon diagnostic work-up, axial SpA was diagnosed in 60.2% of the cohort. Of these, 70% did not fulfil modified New York criteria and, therefore, were classified as having "non-radiographic" axial SpA. Refinement of the candidate criteria resulted in new ASAS classification criteria that are defined as: the presence of sacroiliitis by radiography or by magnetic resonance imaging (MRI) plus at least one SpA feature ("imaging arm") or the presence of HLA-B27 plus at least two SpA features ("clinical arm"). The sensitivity and specificity of the entire set of the new criteria were 82.9% and 84.4%, and for the imaging arm alone 66.2% and 97.3%, respectively. The specificity of the new criteria was much better than that of the European Spondylarthropathy Study Group criteria modified for MRI (sensitivity 85.1%, specificity 65.1%) and slightly better than that of the modified Amor criteria (sensitivity 82.9, specificity 77.5%). The new ASAS classification criteria for axial SpA can reliably classify patients for clinical studies and may help rheumatologists in clinical practice in diagnosing axial SpA in those with chronic back pain. NCT00328068.

Disease status, in terms of disease activity, disease progression and prognosis is difficult to define in ankylosing spondylitis (AS). No gold standard exists. Therefore, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), a self-administered instrument, has been developed as a new approach to defining disease activity in patients with AS. The index, designed by a multidisciplinary team with input from patients, consists of six 10 cm horizontal visual analog scales to measure severity of fatigue, spinal and peripheral joint pain, localized tenderness and morning stiffness (both qualitative and quantitative). The final BASDAI score has a range of 0 to 10. The index was distributed to a cross section of patients, including inpatients receiving 3 weeks of intensive physiotherapy treatment and hospital outpatients. BASDAI was completed by a total of 154 patients. Validation of the new instrument was achieved through analysis of user friendliness, reliability (consistency), score distribution and sensitivity to change. Comparisons were made with a previous Bath disease activity index (DAI) and the Newcastle Enthesis Index. The BASDAI was found by patients to be quick and simple to complete (mean: 67 s). Test-retest reliability was good (r = 0.93; p < 0.001), as was the distribution of scores across the scale (score range: 0.5-10; mean: 4.31). BASDAI was sensitive to change, reflecting a 16% (mean) improvement in inpatient scores after 3 weeks of treatment. It is superior to the DAI in terms of construct and content validity and to the Enthesis Index in all aspects. In summary, BASDAI is user friendly, reliability, sensitive to change and reflects the entire spectrum of disease. It is a comprehensive self-administered instrument for assessing disease activity in AS.

The field of spondyloarthritis (SpA) has experienced major progress in the last decade, especially with regard to new treatments, earlier diagnosis, imaging technology and a better definition of outcome parameters for clinical trials. In the present work, the Assessment in SpondyloArthritis international Society (ASAS) provides a comprehensive handbook on the most relevant aspects for the assessments of spondyloarthritis, covering classification criteria, MRI and x rays for sacroiliac joints and the spine, a complete set of all measurements relevant for clinical trials and international recommendations for the management of SpA. The handbook focuses at this time on axial SpA, with ankylosing spondylitis (AS) being the prototype disease, for which recent progress has been faster than in peripheral SpA. The target audience includes rheumatologists, trial methodologists and any doctor and/or medical student interested in SpA. The focus of this handbook is on practicality, with many examples of MRI and x ray images, which will help to standardise not only patient care but also the design of clinical studies.