Clinical investigations on differentiating Hashimoto's hyperthyroidism from Graves' disease

Abstract

Objective To discuss the values of the fine-needle aspiration cytology (FNAC) and the measurement of the thyroid auto-antibodies in differentiating Hashimoto's hyperthyroidism (HILT) from Graves' disease(GD).Methods 3 FNAC specimens of 362 patients with hyperthyroidism were inadequate for diagnosis.The other 359 patients were divided into four groups based on the FNAC typing:119 cases of HHT,162 cases of GD-Ⅰ,49 cases of GD-Ⅱ,29 cases of GD-Ⅲ.The differences in the levels of thyroid globin antibody (TGAb), thy-roid microsome antibody (TMAb), and thyroid stimulating hormone receptor antibody (TRAb) as well as free thyroid hormones (FT_3, FT_4) in the above four groups were investigated.Results The destroyed and metamor-phic follicle-like epithelia were the characteristic pattern of FNAC in the group of HHT.In the groups of GD-Ⅰ, Ⅱ and Ⅲ, with the increasing of the numbers of lymphocytes infiltration and the decreasing of the epithelia hyperpla-sia, the average levels of TGAb[(43.5±29.0)% ,(61.3±24.4)% ,(68.9±22.3)%]and TMAb[(38.0±26.1)% ,(54.7±23.0)% ,(60.8±22.7)%] showed an ascending tendency in turn while the average levels of TRAb[(57.7±71.0)U/L,(31.5±62.1)U/L,(21.2±47.0) U/L], FT_3 and FT_4 showed a descending tendency.The average levels of TGAb and TMAb in the HHT group were higher than those in the GD-Ⅰ group (P 0.05).The average duration of the diseases in the GD-Ⅲ group was longer than that of the other groups (P 0.05).Conclusion FNAC has an important clinical value in differentiating HHT from GD-Ⅰ,Ⅱ and Ⅲ, while the serum levels of TRAb, TGAb and TMAb have some clinical value in this differentiation from GD-Ⅰ but have little clinical value to differentiate HHT from GD-Ⅱ and Ⅲ. Key words: Hyperthyroidism; Hashimoto's thyroiditis; Graves' disease; Fine-needle aspiration cytology; Thyroid autoantibody