Risk of incident autoimmune diseases in patients with thymectomy

OBJECTIVES: The data concerning the association between Tx and ADs remain unclear and are scarce. This study was undertaken to investigate whether people with Tx are more likely to develop ADs, compared to those without Tx. METHODS: Individuals who received Tx between 2002 and 2015 were identified and matched on age and sex with individuals without Tx. We performed multivariate and stratified analysis using the Kaplan–Meier method and Cox proportional hazards models in order to estimate the association between Tx and the risk of developing ADs. RESULTS: A total of 2550 thymectomized (Txd) patients and 24,664.941 non‐Txd comparison subjects were selected from NHIRD. Tx‐MG (myasthenia gravis) as compared with general population (nonTx‐nonMG), adjusted hazard ratio (aHR) were higher for incident Addison disease (aHR = 10.40, 95% CI 1.01–107), autoimmune hemolytic anemia (aHR = 21.54, 95% CI 2.06–14.8), Hashmoto thyroiditis (aHR = 5.52, 95% CI 1.34–34.7), ankylosing spondylitis (aHR = 2.73, 95% CI 1.09–6.84), rheumatoid arthritis (aHR = 5.25, 95% CI 1.79–15.47), primary Sjogren syndrome (pSS) (aHR = 3.77, 95% CI 1.30–11.0), and systemic lupus erythemtoasus (aHR = 10.40). Tx‐nonMG as compared with general population, aHR were higher for incident autoimmune hemolytic anemia (aHR = 25.50), Hashmoto thyroiditis (aHR = 6.75) and systemic lupus erythematosus (SLE) (aHR = 13.38). NonTx‐MG as compared with general population, aHR were higher for incident Hashmoto thyroiditis (aHR = 6.57), pSS (aHR = 4.50), SLE (aHR = 17.29), and systemic vasculitis (aHR = 25.86). INTERPRETATION: In conclusion, based on a retrospective cohort study throughout Taiwan, patients with Tx have a higher risk of new onset ADs than patients without Tx.