SAT0581 SERIOUS INFECTION RATES WITH BIOLOGICAL DISEASE MODIFYING ANTI-RHEUMATIC AGENTS (bDMARDs) AND PREDISPOSING FACTORS: A 5-YEAR RETROSPECTIVE REVIEW

Background:Biological and targeted synthetic disease modifying anti-rheumatic agents (bDMARDs) increase the risk of serious infections (SIs), however there is limited ‘real-world’ evidence comparing the relative risk of SI for individual bDMARDs. (1,2)Objectives:This study examines the rates of SIs in a non-select Australian Northern Queensland (NQ) cohort of patients with various rheumatic diseases receiving treatment with a bDMARD, to define predisposing factors and directly compare the bDMARDs.Methods:A retrospective review was performed for all patients who received a bDMARD through the Townsville Hospital Rheumatology Department over the 5-year period between June 2013 and May 2018. Episodes of a SI were defined as infection requiring admission or use of intravenous antibiotics. For each bDMARD the rate of SI per 100 patient years (PYs) was calculated and patient demographics and comorbidities were analysed. Between group differences were assessed using independent samples t-tests or ANOVA. Where assumptions were violated, Mann-Whitney U tests or Kruskal-Wallis tests were used. For categorical variables, chi-square tests were used, except when assumptions were violated when Fisher’s Exact tests were used.Results:296 patients received bDMARDs with an overall SI rate of 11.7/100PYs. There was no significant difference in presence of SI by disease type with 24% of patients with rheumatoid arthritis versus 19% with psoriatic arthritis, 14% with ankylosing spondylitis and 29% with “other” (X2=3.11; df=3; p=0.37). Respiratory tract infections were the most common infection (46%) followed by skin and soft tissue infections (23%). The highest incidence rate of SI occurred with rituximab (29.72 SI/100PYs) followed by certolizumab (22.50 SI/100PYs) and tocilizumab (15.00 SI/100PYs). Duration of time on a bDMARD, disease duration and use of methotrexate or leflunomide were not shown to significantly increase the risk of SI for the entire cohort. The characteristics which were shown to significantly increase SI rates were; prednisone use, increasing age, chronic pulmonary comorbidity and specifically in those with rheumatoid arthritis male gender and total duration of bDMARD use.Conclusion:In this real-world NQ cohort of patients treated with a bDMARD for a rheumatic disease, we have identified a number of factors potentially contributing to the risk of the development of SIs. This study provides valuable data on SI rates in an Australian ‘real-world’ cohort that may assist clinicians’ choice of bDMARD in patients with a high baseline risk of infection and highlights the importance of minimising prednisone use in patients on bDMARDs.References:[1]Ramiro S, Sepriano A, Chatzidionysiou K, et al. Safety of synthetic and biological DMARDs: a systematic literature review informing the 2016 update of the EULAR recommendations for management of rheumatoid arthritis. Ann Rheum Dis. 2017;76:1093–1101.[2]Singh J, Wells G, Christensen R, et al. Adverse effects of biologics: a network meta-analysis and Cochrane overview. Cochrane Database Syst Rev. 2011;16:CD008794.Disclosure of Interests: :Kate Celkys: None declared, Jason Ly: None declared, Muriel Soden Speakers bureau: Speaker Fees from Pfizer in 2016