PROTOCOL OUTLINE: This study is a randomized, blinded, controlled study. Patients are stratified in both groups according to prior thymectomy (yes vs no) and by Quantitative Myasthenia Gravis Score (equal to or less than 10 vs greater than 10) so that equal numbers are assigned to each group. Patients in group 2 are also stratified as to whether they are currently on azathioprine.