Prevalence of Autoimmune Disease in Patients with Eosinophilic Esophagitis: A Cross-sectional Study of Three Hospitals in Japan.

Objective Recent studies have found higher rates of autoimmune diseases, such as celiac disease, Crohn's disease, and ulcerative colitis, in patients with eosinophilic esophagitis (EoE) than in the general population. This study investigated the concomitant rate of autoimmune disease among Japanese patients with EoE and evaluated the clinicopathological characteristics of EoE patients with autoimmune disease. Methods The medical records of patients diagnosed with EoE between April 1, 2016, and June 30, 2020, were reviewed. We analyzed the concomitant rate of autoimmune diseases in patients with EoE and compared the clinical and histological differences between patients with and without autoimmune disease. Results Sixty-four patients with EoE were enrolled. Of them, 1 had ulcerative colitis (1.6%), 1 had autoimmune polyendocrine syndrome type 2 (1.6%), and 6 had endometriosis (28.5% of women, 44.4% of reproductive-aged women). No significant differences in the clinical course or histological findings were found between EoE patients with and without autoimmune diseases. No complications, including stenosis, were seen in EoE with autoimmune disease, and most patients with EoE and autoimmune diseases were responsive to proton pump inhibitors (PPIs). Conclusion In this study, 8 out of 64 patients with EoE had an autoimmune-related disease, including ulcerative colitis (n=1, 1.6%), autoimmune polyendocrine syndrome type 2 (n=1, 1.6%), or endometriosis (n=6, 44.4% of women of reproductive age), which is higher than that previously reported in the general population. Further investigations are required to clarify the relationship between EoE and autoimmune diseases.