ABSTRACT
BACKGROUND: There were several reports that thyroid autoimrnune disease commonly found in myasthenia gravis patients. We performed this study to determine the prevalence of thyroid autoimmune disease as well as analyze correlation between acetylcholine receptor antibody and various thyroid autoantibadies among the myasthenia gravis patients in Korea. METHOD: The patient group, 48 patients, diagnosed as myasthenia gravis from January 1985 to December 1995 at the department of Neurology, Internal medicine at Dongsan Medical Center was compaired to the control group, 40 patients, with no age and sex difference from the patient group. The samples were collected from both group for the measure of the values of acetylcholine receptor antibody, thyroid autoantibody and thyroid hormones. RESULT: 1) The values of acetylcholine receptor antibody in myasthenia gravis group and control group were 5.78+-0.7nM and 0.05+-0.06nM respectively. Of 48 patients with myasthenia gravis, 38 patients have been measured acetylcholine receptor antibody value > 0.5nM, Their mean average value was 7.24+-0.66nM. 2) The severe myasthenia gravis group with value of acetylcholine receptor antibody 0.5nM and severe myasthenia gravis group with value of acetylcholine receptor antibody 0.5nM showed thyroglobulin antibody value of 159.6+-79.91IU/mL versus 56.86+-32.99IU/mL. also thyroid microsomal antibody value showed 159.0+-79.9IU/mL and 23.633+-0.19IU/mL respectively. 3) Of 48 myasthenia gravis patients, 12 patients (24%) had high value of antithyroglobulin antibody or anti-microsomal antibody and 5 patients (10%) had both antibodies at the same times. In contrast, only 3 patients (8%) were observed with high value of either one of antibodies. Patient with both antibodies was not observed in normal control group. CONCLUSION: According to the datas we have obtained, appearence of the thyroid autoantibody is significantly greater in severe myasthenia gravis group than normal control group. Therefore it is suggested that the prevalence of thyroid autoimmune disease is higher in severe myasthenia gravis group than mild myasthenia gravis group or normal control group.