[Determination and clinical significance of serum anti-ryanodine receptor antibody in patients with myasthenia gravis].

OBJECTIVE

To explore the clinical significance of serum anti-ryanodine receptor (RyR) antibody in the diagnosis of myasthenia gravis (MG).

METHODS

The crude sarcoplasmic reticulum was prepared from rabbit skeletal muscle, and then purified by differential centrifugation to produce the antigen. The serum anti-RyR antibody levels in 74 patients with MG (including 21 patients with comorbidic thymomas) were determined with ELISA.

RESULTS

Western blot demonstrated the presence of RyR in purified crude sarcoplasmic reticulum. The positive rate of anti-RyR antibody was significantly higher in MG patients who had comorbidic thymoma compared with those who had no such comorbidity (P < 0.01). Also, the positive rate was closely correlated with the severity of MG.

CONCLUSION

Serum anti-RyR antibody test is helpful in the diagnosis of MG associated with thymoma and can be used to judge the outcome of MG.