The Study On The Relationship Between Myasthenia Gravis And Thyroid Abnormal

PURPOSE: To study the relationship of myasthenia gravis and thyroid abnormal. To study the relationship between the AChR antibody and the thyroid related antibodies of myasthenia gravis patients, and to study the clinical features of MG with AChRAb~+TRAb~+.METHODS: First, thyroid function, and thyroid antibodies of 100 MG patients were observed, FT3, FT4, TSH and TRAb, TGAb, TMAb were detected. Then, samples in our study came from 32 MG patients, the AChRAb, TRAb, TGAb and TMAb were measured, the linear relationship between AChRAb and TRAb, AChRAb and TGAb, AChRAb and TMAb were observed. The 32 MG patients were divided into two groups, AChRAb~+TRAb~+ group and non-AChRAb~+TRAb~+ group, and their MGFA clinical classification (according to the standard) and age of MG occurence were compared. To the subtypeâ…¡MG patients, 14 MG patients were divided into two groups, AChRAb~+TRAb~+ group and non-AChRAb~+TRAb~+ group, their first symptoms were compared.RESULTS: Among the 100 MG patients, there were 16 % of them were hyperthyroidism or hypothyroidism, and there were 71 % of the samples were detected out positive thyroid antibody. MG patients with thyroid positive antibody are much more than those with hyperthyroidism and hypothyroidism (X~2 = 4.788, P<0.05) . A linear correlation between AChRAb and TRAb was proved (r=0.609, P=0.0002) . But neither AChRAb and TGAb, nor AChRAb and TMAb showed this relationship (P>0.05) . Between AChRAb~+TRAb~+ group and non-AChRAb~+TRAb~+ group, no significant difference on the clinical classification was found (P>0.05) . Maybe the age of onset was earlier in MG patients with AChRAb~+TRAb~+ than those non-AChRAb~+TRAb~+, but it was still lack of evidence on statistics .To the MG subtypeâ…¡, AChRAb~+TRAb~+ MG patients were most likely to present oclular muscle weakness firstly (P<0.05) .CONCLUSIONS: The incidence of MG patients with thyroid related antibody is much higher than that MG with hyperthyroidism and hypothyroidism , it suggests that there is a cross immunoreaction between the MG related antibody and the thyroid antibody. In MG, there is a linear correlation between AChRAb and TRAb. AChRAb~+TRAb~+ MG mainly present ocular muscle weakness first.