Background: Hashimoto's thyroiditis is in coexistence with many autoimmune disorders, especially celiac disease. There are a limited number of studies evaluating the prevalence of celiac-related antibodies in patients with Hashimoto's thyroiditis.
Objective: This study aimed to further investigate the prevalence of undiagnosed celiac disease in patients with Hashimoto's thyroiditis and the relationship between these two autoimmune disorders in these patients.
Subjects and methods: This study was performed on 82 women aged 20-50 years including 40 patients with Hashimoto's thyroiditis and 42 healthy age-matched individuals. Anthropometric assessments were performed and biochemical parameters including thyroid hormones (TSH, T3 and T4), antithyroid antibodies, anti-tissue transglutaminase and anti-gliadin antibodies were measured by enzyme linked immunosorbent assay (ELISA).
Results: The prevalence of IgG and IgA anti-tissue transglutaminase antibodies and IgA anti-gliadin antibody was higher in Hashimoto's thyroiditis patients compared with control group (15% vs. 7%, 22.5% vs. 17% and 15% vs. 12% respectively). In ordinal regression model, serum IgG anti-tissue transglutaminase and IgA anti-gliadin antibodies were significant predictors of antithyroid antibodies in patients with Hashimoto's thyroiditis (P < 0.05). A significant relationship between serum TSH and IgG anti-gliadin antibody were also found (P = 0.003).
Conclusion: To our findings, a high prevalence of anti-tissue transglutaminase and IgA anti-gliadin antibodies and their positive relationship with antithyroid antibodies in patients with Hashimoto's thyroiditis were reported. These findings further warrant the need for interventions to reduce the prevalence of these antibodies in Hashimoto's thyroiditis for preventing the occurrence of celiac disease in these patients.
Keywords: Hashimoto’s thyroiditis; autoimmune disease; celiac disease.