OP0067 CUMULATIVE ANTIBIOTIC USE AND THE RISK OF DEVELOPING ANKYLOSING SPONDYLITIS: A POPULATION-BASED CASE CONTROL STUDY

Background:Recent studies show possible mechanisms of microbiota alterations that lead to the development of Ankylosing spondylitis (AS). These disturbances in the microbiota can be caused by long-term and high dose intake of antibioticsObjectives:To analyze the association between antibiotic/s use and the risk of developing AS.Methods:Population based case-control study using electronic medical records data from SIDIAP, covering >80% of the population in Catalonia, Spain. AS diagnoses with 2+ years data available were matched to up to 5:1 controls of same age, sex, and GP practice, and similar follow-up. Tracking of antibiotic use in the previous two years was done through pharmacy dispensation data standardized with ATC codes, and categorized in terms of recency of use and quartiles of cumulative dose. Adjusted odds ratios were estimated using conditional logistic regression analyzing antibiotic use (yes/no), recency of intake (current, recent, past, no use) and cumulative dose (quartiles of daily defined doses in the previous two years). All analyses were adjusted for age, body mass index, smoking, co-morbidity, socio-economic deprivation and number of GP visits as a proxy for healthcare resource use.Results:The study included 4,493 cases diagnosed with AS and 22,016 controls. 46.3% of cases and 28.2% of controls had taken antibiotics. An association between taking beta-lactams (OR 1.18 [95% CI: 1.09-1.28]) and taking macrolides (OR 1.34 [95% CI: 1.18-1.52]) and getting diagnosed with AS was found. This association was stronger with current/recent use (Figure 1), but no dose-response pattern was seen (Figure 2).Figure 1.Recency of use and AS diagnosis.Figure 2.Cumulative use and AS diagnosisConclusion:There is an association between use of certain types of antibiotics and the diagnosis of AS, but no dose-response gradient. These data do not support a causal effect of cumulative antibiotic use on the development of AS. More research is needed on the impact of microbiome disturbance on the risk of developing AS.Acknowledgments:Partial support received from the Oxford NIHR Biomedical Research Centre (BRC)Disclosure of Interests:Ana Pascual-Dapena: None declared, Albert Prats-Uribe: None declared, Daniel Prieto-Alhambra Grant/research support from: Professor Prieto-Alhambra has received research Grants from AMGEN, UCB Biopharma and Les Laboratoires Servier, Consultant of: DPA’s department has received fees for consultancy services from UCB Biopharma, Speakers bureau: DPA’s department has received fees for speaker and advisory board membership services from Amgen