The DESIR cohort: a 10-year follow-up of early inflammatory back pain in France: study design and baseline characteristics of the 708 recruited patients.
OBJECTIVES
The French Society of Rheumatology has initiated a large national multicenter, longitudinal, prospective follow-up of patients presenting with early inflammatory back pain in order to set up a database to facilitate several investigations on diagnosis, prognosis, epidemiology, pathogenesis and medico-economics in the field of early inflammatory back pain and spondyloarthritis.


METHODS
Patients were recruited if they had inflammatory back pain of more than 3 months and less than 3 years. Patients will be followed every 6 months during the first 2 years then every year during at least 5years. Apart from information collected on a Case Report Form (demographics, disease activity, severity, co-morbidities, socio-economics, treatments, radiological and MRI evaluation of the spine and the pelvis according to the local investigators, and for some centers bone densitometry and ultrasonography of entheses), the digital X-rays and MRI of the spine and pelvis are stored using a specific software (Carestream) and the biological samples (DNA, RNA, sera, urines) are centralized at the Biological Resources Center (Bichat Hospital).


RESULTS
The recruitment period of the 708 patients (mean age: 34±9years, female 54%, HLA-B27 positive: 57%) in the 25 centers was 26 months (from December 2007 to April 2010). The modified New York criteria, Amor criteria, ESSG criteria and axial ASAS criteria were fulfilled by 26%, 77%, 76% and 67% of the patients at entry, respectively. A history or current symptoms suggestive of peripheral arthritis, acute anterior uveitis and inflammatory bowel disease were observed in 21%, 9% and 4% of the patients, respectively. The disease was active (BASDAI: 45±20) despite an NSAID intake in 66% of the patients.


CONCLUSION
This large cohort should facilitate the conduct of researches in different areas (clinical, medico-economics, translational) in order to improve our knowledge on the pathogenesis and natural history of axial spondyloarthritis.