Background Patients can fulfil the ASAS (Assessment of SpondyloArthritis (SpA) international Society) axial SpA (axSpA) criteria with either objective evidence of sacroiliac joint damage (X-Ray) or inflammation (MRI): (“imaging” arm) or without imaging abnormalities in HLA-B27 positive (or +) patients (“clinical” arm). The clinical arm is not well recognized by the medical community and the health care systems.
Objectives to compare the phenotype but also the impact of the disease on the daily life of the patients with regard to the “imaging” versus the “clinical” arm of early spondyloarthritis patients.
Methods Prospective, multi-centre, observational study. 708 patients with early inflammatory back pain suggestive of spondyloarthritis have been included in the DESIR cohort. Demographics, items of the ASAS AxSpA criteria, disease activity, severity, quality of life, were collected. Statistical analysis: The patients fulfilling the ASAS criteria were splitted in two groups regarding the presence of imaging (X-ray or MRI) abnormalities of the sacroiliac joints (e.g. imaging arm), and within the clinical arm, with regard to the presence of CRP abnormality (e.g. >6mg/L).
Results 682 patients had complete data to permit classification according to the ASAS AxSpA criteria; 476 (69.8%) patients fulfilled them: 296 (60.1%) and 190 (39.9%) the imaging and clinical arm respectively. When comparing both arms (“imaging vs “clinical”) of the ASAS AxSpA criteria, no differences were found in patient characteristics (age, gender, HLAB27+), disease presentation, activity or severity, except for: patients in the ‘imaging arm’ are younger, more frequently male and showed higher CRP values. Multiple logistic regression analysis confirmed the positive association of male gender (OR 1.70 [1.12 – 2.58]) and ASDAS-CRP (2.6[±1.1] vs. 2.3[±1.0], OR 2.44 [1.73 – 3.44]) with the “imaging” arm. The table resumes the description of the different subgroups within the “imaging” and “clinical” arms with regard to the imaging and CRP abnormality.
Conclusions This study suggests that despite some differences (e.g. gender, inflammation) the impact of the disease on daily activities was similar in the imaging and clinical arm and therefore therapeutical strategies and access to care in disabled patients should be identical regardless the arm of the ASAS criteria they are fulfilling.
Acknowledgements This study was finantially supported by a Pfizer grant.
Disclosure of Interest None Declared