RESUMO
AIM: To further investigate the immunologic mechanism of myasthenia gravis(MG). METHODS: Acetylcholine receptor antibodies(AchRab) and presynaptic membrane antibodies (PsMab) was determined by ELISA in 285 cases of MG patients. Tumor necrosis factor- alpha(TNF-?) and RBC-C3b receptor rosette rate(RBC-C3bRR)and RBC-IC rosette rate (RBC-ICR)was determined in 202 patients with MG. Furthermore, the peripheral blood lymphocyte subsets was examined in 104 cases MG patients. RESULTS: The positive rates of the AchRab and PsMab in MG were very significantly higher than that of control.The positive rate of PsMab in patients with negative AchRab was very significantly higher than that of patients with the positive AchRab.In 202 MG patients, the TNF-? was significantly higher, but the RBC-C3bRR was significantly lower than those of control, while the RBC-ICR has no significant change. CONCLUSION: MG is an autoimmune disease with damaged postsynaptic membrane by the AchRab, and some patients with both the AchRab and PsMab could manifest disfunction in the postsynaptic and presynaptic membrane. While the patients who just has the PsMab maybe damaged only in the presynaptic membrane. Other body fluid immune or/and cell immune mechanism may be involved in MG patients without AchRab and PsMab. [