POS1438 EARLY FACTORS ASSOCIATED WITH THE INITIATION OF TREATMENT WITH BIOLOGICS IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS – RESULTS FROM A SINGLE CENTRE RETROSPECTIVE COHORT STUDY
Authors: E. Costa, L. Lages, D. Esperança Almeida, A. M. Gomes Correia, M. Cerqueira, J. Silva, A. R. Ribeiro, J. Redondo Costa, J. Neves
Journal: Annals of the Rheumatic Diseases (2021)

Background: Axial Spondyloarthritis (axSpA) refers to a group of rheumatic diseases that mainly affect the axial skeleton. Treatment with Biological Disease Modifying Anti-Rheumatic Drug (bDMARDs) is indicated when low disease activity is not achieved with Non-Steroid Anti-inflammatory Drugs. Some studies reported that some clinical and socio-demographic were associated with biologics initiation 1,2 . However, early factors associated with the initiation of bDMARDs have not been extensively studied. The authors speculate that certain features early in disease presentation may be associated with future need for treatment with bDMARDs in patients with axSpA. Objectives: To study a population of patients with axSpA and determine whether the presence of certain factors at diagnosis is associated with a later need for biological treatment. Methods: A single centre retrospective study was conducted comprising patients fulfilling the ASAS criteria for axSpA that attended the Rheumatology Outpatient Clinic from January to December 2019. Patients with psoriatic arthritis and enteropathic spondyloarthritis were excluded. All data, except regarding use of bDMARD, refers to the two initial appointments. Between group comparisons were performed through independent sample t-test or Chi-Square as applicable. Logistic Multivariate Regression was performed to understand which factors independently contributed to the use of bDMARDs. Results: One hundred and fifty patients were included, and 52 patients (34,7%) were under biological treatment. In comparison to the group that was not under treatment with bDMARDs, these were significantly more likely to be hard-workers (57,8% vs 29,7%; p =,003), to have had elevated C-Reactive Protein (81,6% vs 48,9%; p &lt;,001), to have had a grade of sacroiliitis greater than 2 (67,4% vs 29,5%; p &lt;,001) and to have history of enthesitis, (32,7% vs 13,3%; p =,006). No differences between groups were found in sex, age, HLA-B27 positivity, state of employment, diagnostic delay, smoking status, history of dactylitis and history of uveitis. In multivariate regression analysis, only the hard-worker type and the highest grade of sacroiliitis were found to be independently associated with the use of bDMARDs as presented in Table 1. Although not statistically significant, a trend to association was found between elevated CRP at diagnosis and use of bDMARDs. Table 1. Multivariate logistic regression of variables associated with initiation of bDMARDs. B S.E. Wald OR 95% CI p Worker type a Non-hard ref. Hard 1,127 ,509 4,890 3.09 1.14 – 8.37 .027* HLA-B27 Negative ref. Positive 1,153 ,670 2,962 3.17 0.85 – 11.77 .085 CRP a Normal ref. Elevated 1,003 ,529 3,591 2.73 0.97 – 7.69 .058 Grade of Sacroiliitis a ≤2 ref. &gt;2 1,485 ,489 9,226 4.41 1.69 – 11.50 .002* History of Enthesitis a No ref. Yes ,299 ,574 ,272 1.35 0.44 – 4.15 .602 a At the time of diagnosis; ref. - reference S.E. – Standard Error; OR – Odds Ratio; CI – Confidence Interval Conclusion: In our study, the performance of work associated with greater biomechanical stress and the presence of greater structural damage at diagnosis were shown to be associated with the latter use of bDMARDs. The authors highlight the importance of recognizing these factors that seem to relate to more aggressive disease, with more structural damage, thus suggesting a need for a tighter control management strategy in these patients accordingly current guidelines. More studies still needed to better depict the influence of certain early clinical and patient related variables in management of axSpA patients. References: [1]Png WY, Kwan YH, Lee YX, et al. Factors Associated with Initiation of Biologics in Patients With Axial Spondyloarthritis in an Urban Asian City: A PRESPOND Study. J Clin Rheumatol . 2019 Mar;25(2):59-64. [2]Inman R, Garrido-Cumbrera M, Chan J , et al SAT0629-HPR FACTORS ASSOCIATED WITH USE OF BIOLOGICAL THERAPIES FOR AXIAL SPONDYLOARTHRITIS IN CANADA. RESULTS FROM THE IMAS SURVEY. Annals of the Rheumatic Diseases 2020; 79: 1274-1275. Disclosure of Interests: None declared