Abstract: Objective  To observe the change of serum thyrophin receptor antibody (TRAb) in patients with Graves’ disease (GD) after 131I radiotherapy, and to investigate its association with early hypothyroidism. Methods  A total of 240 patients with GD were divided into two groups: early hypothyroidism group (n=134), and non-early hypothyroidism group (n=106), according to the occurrence of early hypothyroidism after treatment. Serum concentration of TRAb was measured by radioreceptor assay before, 3, 6 and 12 months after 131I radiotherapy. Results  In both groups, serum TRAb titer increased at the 3rd month, reached the highest level at the 6th month, and returned to the baseline level at the 12th month. The TRAb titer of early hypothyroidism group was higher than that of non-early hypothyroidism group at the 6th month, and there was a significant difference between the two groups (F=13.967, P<0.01). Conclusion  The dynamic change of serum TRAb before and after 131I radiotherapy is closely related to the occurrence of early hypothyroidism, and plays an important role in the prognosis after 131I treatment of GD.

Key words: Graves&rsquo, disease, Thyrotropin receptors antibodies, Iodine radioisotopes, Hypothyroidism