Risk of Autoimmune Diseases Associated with Biologic Agents Targeting Type 2 Immunity: An Observational Study Using a Claims Database

Objective.Biologic agents targeting type 2 immunity (anti-type 2 agents) have been implicated in the risk of autoimmune diseases. This study aimed to assess the association between anti-type 2 agents and the risk of developing autoimmune diseases. Methods.This retrospective cohort, nested case-control study utilized a large claims database in Japan. Patients diagnosed with bronchial asthma, atopic dermatitis, chronic urticaria, or eosinophilic chronic rhinosinusitis after April 2018 were included. The exposures of interest were anti-interleukin (IL)-5, anti-IL-4, and anti-IgE agents. The study outcomes included 11 autoimmune diseases and their composite. The risk of developing autoimmune diseases was assessed using two statistical models: nested case-control analysis (NCC) and time-dependent Cox proportional hazard model (tCox). Results.A total of 886,908 patients were included, with a median age of 42 years (interquartile range: 32.0-52.0). The use of the anti-IL-5 agent and anti-IgE agent showed consistent associations with the composite outcome: adjusted relative risk (RR) 2.50 (95% confidence interval [CI] 1.35, 4.64) in NCC and 3.02 (1.86, 4.90) in tCox, and 2.25 (1.37, 3.67) in NCC and 2.33 (1.61, 3.39) in tCox, respectively. Regarding individual outcomes, rheumatoid arthritis, systemic lupus erythematosus, and anti-neutrophil cytoplasmic antibody-associated vasculitis were associated with the use of anti-IL-5 agents. In patients with atopic dermatitis, anti-IL-4 agents appear to reduce the risk of psoriasis. Conclusion.Although causal interpretation is limited, it provides valuable insights into the association between anti-type 2 agents and autoimmune diseases in real-world clinical practice. Significance and InnovationsO_LIAnti-IL-5 and anti-IgE agents are associated with an increased risk of autoimmune diseases. C_LIO_LIAnti-IL-4 agents show no remarkable link to autoimmune diseases but reduce psoriasis risk in atopic dermatitis. C_LIO_LIThis study explores the effects of anti-type 2 agents and autoimmune diseases in real-world settings. C_LI