Clinical presentation of patients suffering from recent onset chronic inflammatory back pain suggestive of spondyloarthritis: The DESIR cohort

Abstract

Objectives

DESIR is a prospective longitudinal multicentric French cohort of patients with inflammatory back pain suggestive of spondyloarthritis, with a 10-year-follow-up. The purpose is to evaluate the performances of the different sets of classification criteria for axial spondyloarthritis, and to describe the frequency and characteristics of the clinical features of axial spondyloarthritis.

Methods

Demographic data and items allowing classification and indices calculation were collected, as well as biologic and imaging data. Baseline data are analyzed. The performance of the several classification criteria sets was evaluated (likelihood ratio) with the physician's diagnosis as external gold standard. For the clinical presentation of axial spondyloarthritis, a descriptive analysis was conducted.

Results

Seven hundred and eight patients are included. Ninety-two percent of them satisfy at least one set of classification criteria: mNY 26%, Amor 79%, ESSG 78%, ASAS 70%; physician's confidence level 6.8 ± 2.7. 81 and 83% of patients fulfil modified (including MRI) Amor or ESSG criteria. Axial involvement is present in 100% of the cases. NSAIDs are taken by 90%, with an NSAID sore of 50 ± 46. BASDAI over 40 is noted in 60% and elevated CRP in 30% of the cases. HLA-B27 is present in 58%. According to ASDAS CRP levels, 12.7% are in inactive disease, 63% in high disease activity; mean BASFI was 30. Peripheral involvement is present in 57%, with arthritis in 37% of these. Enthesitis is noted in 49% of the patients, and first symptom in 22.5%; anterior chest wall involvement is noted in 44.6%, and dactylitis in 13%. For extra articular manifestations, psoriasis is recorded in 16%, uveitis in 8.5% and IBD in 5.1%. Smoking is present in 36.3% and hypertension in 5.1% of the cases.

Conclusion

These data represent the base of evaluation of the follow-up of this cohort, allowing future specific studies.

Introduction

Spondyloarthritis is probably the first diagnosis to evoke in case of chronic inflammatory back pain occurring before the age of 40 years old [1]. The terminology has changed over the years: Betcherew's disease for our German colleagues [2], ankylosing spondylitis, axial spondyloarthritis [3]. The major difference between ankylosing spondylitis and spondyloarthritis is that ankylosing spondylitis is focused only on the axial symptoms of the disease with structural damage observed on plain X-Rays at the sacroiliac joint level, whereas spondyloarthritis refers not only to the axial symptoms of the disease but also to its other different clinical presentations (e.g. peripheral articular involvement, peripheral enthesitis, extra-rheumatological features such as psoriasis, uveitis, inflammatory bowel disease). Moreover, concerning the axial symptoms, the so called disease “spondyloarthritis” can include patients without structural damage of the sacroiliac joints [4].

Concerning the criteria proposed to classify the patients suffering from this disease, the conventional ones are the modified New York criteria [5]. Such criteria are making as mandatory the presence of structural damage of the sacroiliac joints on pelvic X-rays (commonly but wrongly named “sacroiliitis” since “itis” should refer to an inflammation whereas the pelvic X-rays are only able to detect structural damage such as joint erosions and sub-chondral bone sclerosis).

In the 1980s, criteria have been proposed with the possibility to recognize patients without structural damage at the sacroiliac joints and with the recognition of the importance of the different clinical manifestations observed in such patients (e.g. the Amor criteria [6] and the European Spondyloarthritis Study group criteria [7]). It must be recognized that despite their relevant psychometric properties, in particular the ones of the Amor criteria [8], such criteria have not been used so widely and in particular, only rare therapeutical trials have been conducted by pharmaceutical companies with reference to this criteria for enrolling the patients [9], [10].

The international society focused on the different outcome measures/criteria in the area of spondyloarthritis (e.g. Assessment of Spondylo Arthritis [ASAS]) has elaborated a new set of criteria for spondyloarthritis [11] including not only the previous items (e.g. all the different clinical features of spondyloarthritis, the possibility to recognize patients without objective structural damage of the sacroiliac joints on pelvic X-rays) but also considering the importance of objective signs of inflammation (e.g. subchondral bone edema of the sacroiliac joints at MRI [12]). Such criteria have been widely used in particular by pharmaceutical companies who have started to conduct studies referring to such new criteria. Some recent trials have even been focused on patients with non-radiographic axial spondyloarthritis [13], [14]. Such criteria are classification criteria and therefore are performing well in patients with established disease. However, their performances at an early stage of the disease have been less investigated. Moreover, in case of a patient presenting with axial symptoms, the frequency of other clinical spondyloarthritis features remains to be investigated.

The French Society of Rheumatology has recently initiated a huge national multicenter cohort, the so-called “DESIR cohort study” (Devenir des spondyloarthrites indifférenciées récentes [DESIR]) to facilitate investigations on diagnostic and prognostic markers but also aetiologic, pathogenic and socio-economic factors among patients with early inflammatory back pain suggestive of axial spondyloarthritis [15].

These preliminary remarks prompted us to conduct an analysis of the patients enrolled in the DESIR cohort in order to evaluate the properties of the different sets of criteria and to describe the frequency and the characteristics of the different clinical features of spondyloarthritis.