Prevalence of thyroid autoantibodies in a large series of sarcoidosis patients: Implications for autoimmune thyroid disease screening

Background and aim: Sarcoidosis is a potentially multisystem granulomatous disease frequently associated with autoimmunity. Previous cohort studies have reported an elevated risk of developing autoimmune thyroid disease (AITD) in sarcoidosis patients. Aim of the study was to assess the prevalence of thyroid autoimmunity in a large, biopsy-proven sarcoidosis cohort and compare it to established general population rates, thereby highlighting the clinical significance of screening. Methods: To explore the prevalence of AITD, we examined a cross-sectional cohort of 668 patients with biopsy-proven sarcoidosis. Serum Thyroperoxidase Antibodies (TPOAb) and Thyroglobulin Antibodies (TgAb) were quantified using standard electrochemiluminescence immunoassays (ECLIA). The prevalence of positive thyroid autoantibodies was compared to previously published regional healthy control rates (11.4%, n=1,108) using a two-sample Z-test for comparing two proportions. Results: The overall prevalence of positive thyroid autoantibodies (TPOAb and/or TgAb) in the sarcoidosis cohort (n=668) was found to be 27.4% (95% CI: 21.7%–28.3%). This rate was significantly higher compared to the pooled historical control group prevalence of 11.4% (p < 0.001). Conclusion: The prevalence of positive thyroid autoantibodies in patients with sarcoidosis is significantly elevated compared to the healthy population. This finding underscores the strong autoimmune linkage between sarcoidosis and AITD and supports the recommendation for systematic screening for thyroid autoimmunity in patients diagnosed with sarcoidosis.