[Autoantibody against Na+/I- symporter (NaIS)]

Na+/I- symporter (NaIS) cDNA was first cloned in 1996. Endo et al. reported that autoantibody against NaIS was found in 84% sera from patients with Graves' disease and 12% sera from patients with Hashimoto's thyroiditis. These IgGs, purified from sera from patients with Hashimoto's thyroiditis, caused 14 to 62% inhibition of iodide uptake. Furthermore, Ajjan et al. reported that 30.7% sera from patients with Graves' disease inhibited 7 to 44% of iodide uptake. In addition, Morris et al. suggested that NaIS represents an important autoantigen in autoimmune thyroid disease. In conclusion, it is suggested that the incidence of the antibodies against NaIS is higher in Graves' disease than Hashimoto's thyroiditis, and these antibodies inhibit iodide uptake.