Acetylcholine receptor antibody in Thai generalized myasthenia gravis patients.

ABSTRACT

The authors studied acetylcholine receptor antibody (AChR Ab) in twenty-six Thai patients diagnosed as having generalized myasthenia gravis and fifteen control cases. AChR Ab assay was done by radio-immunoassay technique and reported by titer in nmole/L. The positive result was defined by titer more than 0.5 nmole/L. In the myasthenia gravis group, age ranged from 18 to 64 years old with mean of 34 years old. The female male ratio was 4.21. Duration of disease before taking blood sample ranged from 1 month to 14 years with a mean of 3.9 year The AChR Ab could be detected in 21 out of 26 patients (80.7%). In the control group, tests were all negative. The results of the test made the sensitivity of 80.7% and specificity of 100%. The positive predictive value was 100%, the negative predictive value was 75%, and the prevalence was 60.3%. There was no correlation between AChR Ab titer and clinical features. This test is a very valuable test in case of uncertainly in the diagnosis of myasthenia gravis.