Background Clinical similarity of nr-axSpA and ankylosing spondylitis (AS) has been well established, but whether nr-axSpA is an initial stage of AS, or these two subtypes are nosologically self-determined entities is still being debated.
Objectives To study the evolution of early axial spondyloarthritis (axSpA) in the Moscow axSpA cohort of patients (pts) - CoRSaR (Russian acronym from CohoRt of early axSpA pts).
Methods Currently the CoRSaR cohort includes 94 axSpA pts with <5 years of inflammatory back pain duration (ASAS 2009y.criteria). 54 out of them with at least 12 months (mo) follow up pts (FUP) were included into preliminary analysis of axSpA evolution study. Evaluation of all pts at inclusion (Mo0) and FUP (Mo12) visits was similar and included: medical case history, clinical examination, X-ray of pelvis (and other segments of the back bone and joints, when necessary) - following ASAS guidelines, MRI of sacroiliac joints. Pts' mean age at Mo0 visit was 27,1±5,5 y., average disease duration - 22,4±15,1 mo, 49 (90,7%) pts were HLA-B27 positive.
Results Pts were grouped into 2 arms to analyze axSpA evolution: Group 1 – nr-axSpA, Group 2 – AS. The table shows pts' baseline and FUP Mo12 visit characteristics. No significant difference has been found between the two groups – radiographic AS and nr-axSpA - in terms of prevalence of arthritis, enthesitis, BASDAI, ASDAS CRP, and BASFI scores. Radiographic sacroiliitis, i.e., AS, has developed in 9 (39%) out of 23 nr-axSpA pts during 12 Mo FUP.
Conclusions No clinical differences between radiologically confirmed axSpA (i.e., AS) and nr-axSpA were established. AS has developed in 9 (39%) out of 23 nr-axSpA pts during 12 Mo.
Disclosure of Interest None declared