RESUMEN
Objective To study the relationship of levels of acetylcholine receptor antibody (AChRAb) and thyroid antibodies in patients with myasthenia gravis (MG) and thyroidism. Methods Thyroid function of FT3, FT4 and TSH, and thyroid antibodies including TSH receptor antibody ( TRAb), thyroid globulin antibody (TGAb) and thyroid microsome antibody (TMAb) were detected in 100 patients with MG and 100 healthy controls. Among them, 32 patients were further tested for AChRAb. The relationship between AChRAb and each of TRAb, TGAb and TMAb was analyzed along with their relevant clinical characteristics. Results Of 100 patients with MG, 12 cases ( 12% ) were hyperthyroidism and 4 cases (4%) were hypothyroidism, and 71 cases (71%) were thyroid antibodies positive. The percent of thyroid antibodies positive cases was significantly higher than that of thyroidism cases (χ2=4. 788, P < 0. 05 ). Analysis on AChRAb and TRAb in 32 AChRAb tested cases demonstrated a linear correlation (r= 0. 609, P = 0. 0002). Conclusions The incidence of thyroid antibody positive in MG cases is significantly higher than incidence of hyperthyroidism and hypothyroidism in MG. AChRAb and TRAb has a linear correlation.