The patient is a 35-year-old woman with myasthenia gravis, class IIa. She complains of diplopia and fatigue and weakness that affects mainly her upper limbs. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She takes pyridostigmine 60 mg three times a day. But she still has some symptoms that interfere with her job. She is a research coordinator and has 3 children. Her 70-year-old father has hypertension.  She does not smoke or use illicit drugs. She drinks alcohol occasionally at social events. Her physical exam and lab studies were not remarkable for any other abnormalities.
BP: 110/75
Hgb: 11 g/dl
WBC: 8000 /mm3
Plt: 300000 /ml
Creatinine: 0.5 mg/dl
BUN: 10 mg/dl
Beta hcg: negative for pregnancy