Polymorphisms in TSHR and IL1RN genes and the risk and prognosis of Hashimoto’s thyroiditis

Abstract

Hashimoto’s thyroiditis (HT) is a complex genetic autoimmune thyroid disease (AITD). Thyroid-stimulating hormone receptor (TSHR) is considered as candidate gene in AITD. IL1RN gene is involved in the pathogenesis of a number of autoimmune diseases. These findings prompted us to investigate the association of TSHR and IL1RN genes polymorphism with the risk and the prognosis of HT in Tunisia. A total of 249 healthy controls and 202 patients with HT were genotyped for TSHR D727E and IL1RN^VNTR polymorphism. No significant difference was found for D727E polymorphism between HT patients and healthy controls. For IL1RN gene, we found an association between HT and IL1RN^VNTR polymorphism. The A1A3 genotype was more prevalent in HT patients than in controls. However, the A1A4 genotype was associated with HT as a protective factor. Significant association of the TSHR polymorphism with lower plasma TSH level in HT patients has been detected. We found for the first time an association of IL1RN^VNTR polymorphism with the production of anti-thyroid peroxidase antibody at the onset of disease. These preliminary results suggest that only the IL1RN^VNTR polymorphism may be associated with HT susceptibility and that TSHR and IL1RN^VNTR polymorphisms may represent prognostic factors for predicting the severity of HT.

• Anti-thyroglobulin antibody
• anti-thyroid peroxidase antibody
• HT
• IL1RN
• TSHR

Acknowledgements

We gratefully acknowledge the staff of the departments of endocrinology and blood bank of the CHU F. Bourguiba of Monastir, for providing samples and clinical information.