Roles of TgAb and TPOAb in the Development of Hypothyroidism After ¹³¹I Treatment in Hyperthyroid Patients With Graves’ Disease

To evaluate the roles of antithyroid peroxidase antibodies (TPOAb) and antithyroglobulin antibodies (TgAb) in the development of hypothyroidism after ¹³¹I treatment in hyperthyroid patients with Graves’ disease(GD), data were collected from 160 GD patients who were treated with ¹³¹I in the department of nuclear medicine of Tongji Hospital between January 2008 and February 2011. Patients were divided into four groups: group A (TgAb＜60.00 U/mL，TPOAb＜60.00 U/mL), group B (TgAb≥60.00 U/mL, TPOAb＜60.00 U/mL), group C (TgAb＜60.00 U/mL, TPOAb≥60.00 U/mL), and group D (TgAb≥60.00 U/mL, TPOAb≥60.00 U/mL). Chisquare criterion and logistic regression analysis were used to evaluate the roles of TPOAb and TgAb in the development of hypothyroidism.The results showed that hypothyroidism was observed in 34.4% of the patients with GD treated with ¹³¹I. The incidence of hypothyroidism after ¹³¹I treatment was different for each group(P=0.034＜0.05), with group C and D having significantly higher incidence than group A (P=0.041＜0.05 and P=0.005＜0.01, respectively). Logistic regression analysis showed that the TGAb levels (Wald = 4.145, P=0.042 <0.05) and the TPOAb levels (Wald = 6.850, P=0.009 <0.01) played important roles in the occurrence of hypothyroidism after ¹³¹I treatment. In conclusion, because TgAb and TPOAb play important roles in the occurrence of hypothyroidism after ¹³¹I therapy, in patients with positive levels of TgAb and TPOAb, lower doses of ¹³¹I might prevent hypothyroidism.