Ab0636 Risk of Tuberculosis in Patients With Rheumatoid Arthritis: A Nationwide Population-Based Cohort Study

Background: Patients with rheumatoid arthritis (RA) are known to have an increased risk of tuberculosis, particularly in association with the use of biologic disease-modifying anti-rheumatic drugs (bDMARD) including tumor necrosis factor-α (TNF-α) inhibitors. Korea is a country with an intermediate risk of tuberculosis, and large-scale studies on the risk of tuberculosis in patients with RA in Korea are still lacking. Objectives: Our study aimed to identify the risk of tuberculosis in patients with RA compared to the general population in a large population-based cohort, and to identify factors associated with the risk of tuberculosis in patients with RA. Methods: Among patients diagnosed with RA between 2010 and 2017, patients who had undergone a national health examination within two years prior to RA diagnosis were included in the study (n = 59,577). Control group included age- and sex-matched non-RA controls who received a health check-up at the same time as RA patients (n = 297,885). The primary outcome of the study was incident tuberculosis, which was defined by an ICD-10 code and enrollment in the rare intractable disease program. Kaplan-Meier curves and Cox proportional hazards regression analysis were used for the analysis. Results: During a mean follow-up period of 4.5 ± 2.2 years, 979 subjects in the control group and 619 patients in the RA group developed tuberculosis. Patients with RA had a 3-fold higher risk of tuberculosis than age- and sex-matched non-RA controls (adjusted hazard ratio aHR 3.02, 95% confidence interval CI 2.73–3.35). The association between RA and tuberculosis was more prominent in young adults aged 20-39 years. Using the control group as the reference, the aHR of tuberculosis in bDMARD-naïve patients with RA was 2.87 (95% CI 2.58–3.19), and the aHR of tuberculosis in bDMARD-exposed patients with RA was 4.97 (95% CI 3.92–6.29). In patients with RA, male sex, advanced age, underweight, diabetes, hypertension, airway disease, and bDMARD exposure were associated with an increased risk of tuberculosis. Conclusion: In a nationwide population-based cohort in Korea with a intermediate risk of tuberculosis, patients with RA had a three-fold higher risk of tuberculosis than age- and sex-matched controls, and even bDMARD-naïve patients had a higher risk of tuberculosis than the general population. Even in patients who do not use bDMARDs, if suspicious symptoms occur, the possibility of tuberculosis should be considered. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.