[Two cases of myasthenia gravis associated with transient amenorrhea]

Two cases of acquired autoimmune myasthenia gravis (MG) presenting transient amenorrhea were reported. Case 1, 28 years old, developed blepharoptosis and generalized fatigability at the age of 20 years. She had been treated only by anti-cholinesterase. Amenorrhea appeared at the age of 26 years. Then, physical examinations showed normal secondary sexual development and moderate myasthenic features. On laboratory examinations, SLE findings such as leucopenia (1,600/mm3), biologically false positivity in the serological tests for syphilis, negative Mantoux reaction, positive anti-nuclear and -DNA antibodies, were noted. Anti-AChR antibody was highly positive (max.: 353 nmol/l). Decreased E2 (13-15 pg/ml) and progesterone (0.21-0.29 ng/ml) values in serum, elevated LH (110-160 mIU/ml) and FSH (78-90 mIU/ml) and highly reactive LH-RH loading test were consistent with the hypergonadotropic hypogonadism. Thymus pathology of thymectomy which was done during amenorrhea, showed hyperplasia. Bilateral ovarian biopsy revealed a number of arrested primordial follicles, but neither inflammatory changes nor fibrosis. Immune complexes were not localized in the ovarian biopsy. The Kaufmann's therapy aggravated myasthenic symptoms. Menstruation recurred after 13 months of thymectomy. Amenorrhea continued for 18 months. Case 2, 37 years old, has had anti-epileptic regimens since the age of 4 years. She has been highly myasthenic for 15 years and treated by thymectomy, steroid hormone, plasmapheresis and some other therapies for 10 years. Amenorrhea occurred at the age of 34 years. Sexual development was normal. Myasthenia was very severe. On laboratory examinations, anti-AChR antibody was positive (max.: 941 nmol/l). Transient elevation of serum LH (37 mIU/l) and FSH (14 mIU/l) values was observed.(ABSTRACT TRUNCATED AT 250 WORDS)