The Essential Role of Anti-Thyroid Antibodies in Chronic Idiopathic Urticaria

Background. An autoimmune etiology has been suggested in up to one-third of cases of chronic idiopathic urticaria (CIU), in which it has been proposed that a subset of cases are associated with thyroid autoimmunity. The objective of our present study was to verify the prevalence of thyroid antibodies in the patients with CIU. Methods. Sixty patients aged 12-51 years, who met criteria for CIU, and 40 aged-matched healthy controls (18 males and 22 females) were participated in this study. Serum anti-thyroid antibodies (ATAs), thyroid hormones, total immunoglobulin E (IgE), and food allergen-specific IgE antibodies were measured. The CIU group was treated with anti-H1 and anti-H2 histamines for 3 weeks. Results. The total ATA positive rate was 27.3% (33% males and 25% females) in the CIU group. The prevalence of anti-thyroglobulin antibodies, anti-TSH-receptor antibodies, and anti-thyroid peroxidase antibodies were 16.6%, 83.3%, and 8.3%, respectively. The thyroid hormones, T3, and T4, and the TSH were within the normal limits. The radioallergosorbent test was negative for food allergens, and only 18% of the patients had a total IgE concentration >200 IU/mL. Conclusion. ATAs were found in 27% of the patients with CIU, but these antibodies did not dysregulate thyroid hormone secretion nor did they mediate any clinical manifestations.