The relationship between transforming growth factor-beta1, vascular endothelial growth factor, nitric oxide and Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is one of the autoimmune disorders of the thyroid gland. The pathogenesis of HT has not been clearly understood. This study was designed to investigate plasma transforming growth factor-beta1 (TGF-beta1), vascular endothelial growth factor (VEGF), and nitrate/nitrite (NOx - two end products of nitric oxide [NO] metabolism) in HT. Forty patients diagnosed HT and 40 age- and sex-matched healthy controls were included in the study. TGF-beta1 and VEGF levels were measured by ELISA, NOx levels were measured spectrophotometrically. Plasma TGF-beta1 and VEGF were decreased, and NOx increased in HT patients in comparison with controls. There was a significant correlation between TGF-beta1 and VEGF, and weak but significant correlation between TGF-beta1 and NOx in HT. This study indicates that TGF-beta1, VEGF and NO probably have a role in the pathogenesis of Hashimoto's thyroiditis, and development of autoimmunity. Clearly, further studies are necessary to establish the exact mechanism of TGF-beta1, VEGF and NO interaction in Hashimoto's thyroiditis.