Ab1039 a Comparative Study to Assess the Differences in Disease Characteristics in Patients With Non-Radiographic and Radiographic Axial Spondyloarthritis

Abstract

BackgroundSpondyloarthritis (SpA) is an umbrella term for a group of clinically heterogeneous chronic inflammatory diseases, with Ankylosing Spondylitis (AS) having the characteristic radiographic features of sacroiliitis and spinal deformities, while the other subtypes of SpA have some common as well as unique articular and extra-articular manifestations. Recent advances in early diagnosis have differentiated axial SpA into radiographic and non-radiographic subsets but the exact differences between them are debatable.ObjectivesThis study was conducted to assess and compare the clinical, laboratory, and radiologic characteristics of Indian patients with radiographic and non-radiographic axial SpA.MethodsThis was a cross-sectional, observational, comparative study conducted at a 1250-bedded tertiary care hospital. Between February 2020 and December 2021, all consecutive adult patients classified as having Axial Spondyloarthritis as per the Assessment of Spondyloarthritis international Society (ASAS) 2009 Classification Criteria and with symptom duration of at least 3 years were included in the study after taking their informed consent. Patients were classified as radiographic (AS) or non-radiographic Axial SpA (nr-Axial SpA) by two independent and blinded rheumatologists with over twenty years of experience in their field each, based on findings on anteroposterior plain radiographs in the supine position. Demographic details, articular and extra-articular manifestations, comorbidities, and relevant family history were assessed along with the levels of inflammatory markers and HLA B27 status. The study was approved by the Institutional Review Board and the Institutional Ethics Committee.Results209 patients consented to this study, with 160 being classified as radiographic and 49 as non-radiographic axial SpA. 79.4% of the patients were male. The mean age at symptom onset was 27.69 ± 9.33 years for our cohort, with a median duration of 50 months. There was a significantly higher proportion of males (85% vs 15%, p <0.001), patients with enthesitis (74% vs 41%, p 0.05), and hypertension among the radiographic subgroup. 44% of our patients had bilateral Grade 2 changes on their sacroiliac joint radiographs according to the modified New York Criteria, and there was a significant positive correlation between increasing symptom duration and worsening radiographic grades of sacroiliitis, but there were no significant differences in the remaining clinical features, HLA B27 positivity, or age at symptom onset among the AS and nr-Axial SpA patients. Mean values of BASDAI, BASMI, and ASDAS-ESR scores were also significantly higher in patients with radiographic Axial SpA.ConclusionData from our Indian cohort of axial Spondyloarthritis revealed a significant association of radiographic disease with male gender and the presence of enthesitis, as well as higher mean values of inflammatory markers and composite scores. However, non-radiographic axial SpA was similar to AS as far as most other features were concerned. With increasing symptom duration, the majority of patients may develop radiographic disease, and they may be considered as two ends of the same spectrum, justifying early therapy even in nr-axial SpA.References[1]Baraliakos X, Braun J. Non-radiographic axial spondyloarthritis and ankylosing spondylitis: what are the similarities and differences?. RMD open. 2015 Aug 1;1(Suppl 1):e000053.[2]López-Medina C, Molto A, Claudepierre P, Dougados M. Clinical manifestations, disease activity and disease burden of radiographic versus non-radiographic axial spondyloarthritis over 5 years of follow-up in the DESIR cohort. Annals of the rheumatic diseases. 2020 Feb 1;79(2):209-16.[3]Poddubnyy D, Rudwaleit M, Haibel H, Listing J, Märker-Hermann E, Zeidler H, Braun J, Sieper J. Rates and predictors of radiographic sacroiliitis progression over 2 years in patients with axial spondyloarthritis. Annals of the rheumatic diseases. 2011 Aug 1;70(8):1369-74.Acknowledgements:NIL.Disclosure of InterestsNone Declared.