Results from Polish Spondyloarthritis Initiative registry (PolSPI) : methodology and data from : the first year of observation

Objectives: Report on one-year results from the Polish Spondyloarthritis Initiative registry (PolSPI), containing the cross-sectional analysis of clinical and imaging data as well as database methodology. Material and methods: The PolSPI registry includes patients with axial (axSpA) and peripheral (per- SpA) spondyloarthritis according to ASAS classification criteria, and/or patients with ankylosing spondylitis according to modified New York criteria, psoriatic arthritis according to CASPAR criteria, arthropathy in inflammatory bowel disease, reactive arthritis, juvenile spondyloarthritis or undifferentiated spondyloarthritis. Epidemiologic data and history of signs, symptoms and treatment of spondyloarthritis are collected and assessment of disease activity is performed. Radiographic images of sacroiliac joint, cervical and lumbar spine, and results of bone densitometry are collected. Every 6 months blood samples for inflammatory markers, and for long-term storage are taken. Results: During a one-year period from September 2015 to August 2016, 63 patients were registered on an electronic database; 44 (69.8%) of patients were classified as axial spondyloarthritis (axSpA) and 19 (30.2%) as peripheral spondyloarthritis (perSpA) according to ASAS criteria. Statistically significant differences between axSpA and perSpA were discovered in the percentage of HLA-B27 antigen occurrence (92.6% and 50%, respectively), BASDAI (2.8% and 4.1%, respectively), DAS 28 (2.66% and 4.03%, respectively), percentage of peripheral arthritis (20% and 88.8%, respectively), enthesitis (26.7% and 70.6%, respectively), dactylitis (6.7% and 88.9%, respectively), as well as extra-articular symptoms: acute anterior uveitis (26.7% and 5.6% , respectively) and psoriasis (6.9% and 55.6%, respectively). Patients with axSpA had significantly higher mean grade of sacroiliac involvement according to New York criteria, higher mSASSS score, and lower T-score in femoral neck in bone densitometry. Conclusions: At the early stage of the disease patients with axSpA compared to those with perSpA, have more advanced structural damage of sacroiliac joints and spine, and lower bone mineral density in the femoral neck. In the upcoming years the PolSPI registry will prospectively follow-up patients with SpA, recording response to treatment and carrying out research on interaction of inflammation and bone remodelling.