THE EVOLUTION OF AXIAL SPONDYLOARTHRITIS DURING 12-MONTH FOLLOW-UP STUDY OF A CORSAR COHORT

Until recently there is no clarity in the nosological independence of non-radiographic axial spondyloarthritis (nraxSpA). Cohort studies can assist in solving this problem. In 2013, the V.A. Nasonova Research Institute of Rheumatology started to form a Cost and Resource utilization Study in Antiretroviral treated patients (CoRSaR) cohort to investigate the evolution of nr-axSpA and treatment policy for this condition. This communication deals with the preliminary results of a 12-month follow-up study of the CoRSaR cohort. Subjects and methods. The cohort was recruited from all consecutive patients with a < 5-year history of nr-axSpA who sought for medical advice and treatment. The patients were examined in accordance with the Ankylosing Spondylitis Assessments (ASAS) International Working Group guidelines at inclusion and after 12 months. A total of 94 patients with axSpA were enrolled; 54 patients out of them were included into a preliminary analysis of the evolution of axSpA; their mean age at inclusion was 27.1±5.5 years and the mean disease duration was 22.4±15.1 months; 49 (90.7%) patients were HLA-B27 positive. 31 of the 54 patients had ankylosing spondylitis(AS) and 23 had nr-axSpA. Results and discussion. The patients with AS and those with nr-axSpA showed virtually no difference in main clinical parameters, such as the presence of arthritis, enthesitis, BASDAI, ASDAS-CRP, and BASFI. By the end of the 12month follow-up, both groups virtually displayed almost a double reduction in all inflammatory markers but erythrocyte sedimentation rate. Nine (39%) patients with nr-axSpA developed radiographic sacroiliitis over 12 months and the diagnosis of AS was confirmed. Conclusion. 39% patients with nr-axSpA developed radiographic sacroiliitis at the 12-month follow-up. Nr-axSpA should be regarded as an early stage of AS.