AB1335 WHAT IS THE REAL ASSOCIATION’S FREQUENCY OF IMMUNE-MEDIATED INFLAMMATORY DISEASES? STUDY OF 6686 CASES
Authors: E. Robin, F. Boudis, A. Bruandet, M. Nachury, D. Staumont, R. M. Flipo, J. G. Letarouilly
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Spondyloarthritis (SpA), inflammatory bowel disease (IBD) and psoriasis are immune-mediated inflammatory diseases that share similarities and could be associated in several patients. Genetic, immunological, and infectious causes have been suggested. Their prevalence has increased over time; however, recent epidemiological data are lacking in that field [1]. Moreover, the choice of treatment depends on the associations of these pathologies. <h3>Objectives:</h3> The main objective of our study was to assess the frequency of association between these three pathologies using the healthcare data warehouse (HDW) of a tertiary health centre. The secondary objective was to specify the SpA phenotype. <h3>Methods:</h3> We conducted a cross-sectional study of the first visit of patients with SpA, IBD or psoriasis in the rheumatology, gastroenterology, and dermatology departments, respectively, in a University Hospital between January 1<sup>st</sup>, 2008, and December 31<sup>st</sup>, 2021. Data were collected by keyword search within the HDW mailings, supplemented by a systematic expert review. A descriptive analysis presenting the probability of having several pathologies was performed. <h3>Results:</h3> Of the 6686 patients included, 1951 had SpA, 3444 had IBD and 1932 had psoriasis. 9% of the patients included had multiple pathologies (Figure 1): they were older (p&lt;0.001), and rheumatology units were more likely to manage these patients (p &lt; 0.001); there was no difference in the patient's gender (p=0.75). The proportions of patients with multiple pathologies were 29% for SpA (21% psoriasis, 8% IBD), 25% psoriasis (21% SpA, 4% IBD) and 7% for IBD (5% SpA, 2% psoriasis). The SpA phenotypes were axial SpA (36%), psoriatic arthritis (34%), IBD-associated SpA (9%), peripheral SpA (6%), mixed SpA (4%), SAPHO (2%), juvenile SpA (1%), reactive arthritis (1%) or no described phenotype (7%). Of note, 27% of patients detected by keyword search did not present the diagnosis on rereading and were therefore not included. <h3>Conclusion:</h3> Patients with SpA or psoriasis appear to have a greater risk of presenting with a combination of pathologies compared to IBD patients, and rheumatologists also seem to be more likely to manage patients with these associations. Hospital-based HDW are an exciting tool for epidemiology care. Still, they could be, maybe, enhanced by artificial intelligence systems (with, for example, the identification of risk factors associated with the highest rates of association). A complementary longitudinal study or an assessment of associations over time could provide information on the temporal evolution of these associations, probably conditioned by the increase in incidences and the optimisation of screening and referrals. <h3>REFERENCES:</h3> [1] Fakih O, Prati C, Wendling D, Verhoeven F. Differences in distribution by department of prevalence and incidence of spondyloarthritis and inflammatory bowel diseases declared to the French National Health Insurance and their evolution between 2008 and 2018. Joint Bone Spine. 1 mars 2022;89(2):105289. <h3>Acknowledgements:</h3> I would like to thank all the co-authors, the FHU PRECISE and the INCLUDE team with whom we collaborated on this project. <h3>Disclosure of Interests:</h3> <b>None declared.</b>