T suppressor cell function in patients with myasthenia gravis

The activities of Con A-induced Suppressor Cells (Con-ASC) were determined in 50 patients with myasthenia gravis (MG) and 24 healthy controls. The ConA-SC activity of the patients with MG was significantly decreased as compared with that of the controls (10.06%) versus 25.28%, (P less than 0.01). Furthermore, the patients with generalized myasthenia gravis (GMG) had a lower ConA-SC activity than those with extraocular muscle myasthenia gravis (EMMG) (9.37% versus 12.13%, P less than 0.05), but their serum anti-acetylcholine receptor antibody titer was higher than that of patients with EMMG (20.55 x 10(-9) M versus 2.4 x 10(-9) M, P less than 0.01). No correlation found between the ConA-SC activity and the sex or duration of disease of the MG patients. And no effects of prednisone and thymectomy were found on the ConA-SC activity of MG patients. The results of the study suggested that the decreased function of suppressor T lymphocytes might play an important role in the pathogenesis of MG.