The case report, titled “Clinical characteristics and relationship between myasthenia gravis and premature ovarian failure: report of two cases,” was published in the Journal of International Medical Research.
POF is a syndrome in which menstruation suddenly stops after puberty but before the age of 40. This can result in abnormal levels of reproductive hormones, hot flashes, and infertility.
MG and POF are both relatively rare conditions. In the report, researchers detail the cases of two MG patients who also experienced POF.
The first patient was 20 years old, female, and was hospitalized in late 2015 due to unexplained exhaustion. A battery of tests led to a diagnosis of simultaneous MG, systemic lupus erythematosus, and Sjogren’s syndrome. The patient was given treatment that included prednisone and Mestinon (pyridostigmine). Her symptoms improved, and the patient was discharged.
However, in January 2016, the young woman was re-admitted to the hospital due to continued muscle weakness, particularly after exercise. In addition, the patient hadn’t had a period since November 2015, and measurements of her reproductive hormones showed abnormalities. Because of this, the woman also was diagnosed with POF.
During the hospitalization, the patient experienced MG crisis — muscle weakness that leads to respiratory failure — making it difficult to breath. She was put on a ventilator and treated intensively, which included intravenous methylprednisolone and blood filtering. Gradually, the young woman was stabilized and was later discharged, with instructions to continue taking Mestinon, mycophenolate mofetil, and oral methylprednisolone.
After the MG was under control, the patient resumed normal menstruation. At follow-up six months after discharge, her sex hormones were confirmed to be back in normal ranges.
The second patient described in the case report had a similar story. Also young — age 21 — and female, the patient was diagnosed with MG in 2015 after multiple hospital visits and more than a year of physical symptoms. Those included eyelid drooping, double-vision, and no menstruation. The young woman was prescribed Mestinon, and her MG improved greatly. However, her periods did not return to normal, even after getting injections with the hormone progesterone.
Then, in 2016, an infection triggered an MG crisis, and the patient was hospitalized and treated for MG, and symptomatically. The woman’s condition gradually improved, and she was moved to maintenance therapy with Mestinon.
Even with the MG under control, as of December 2016, the patient still wasn’t having periods. This — combined with abnormal hormone levels similar to the first patient — led to a diagnosis of POF. As of the publishing of the case report, the woman’s POF remained unresolved.
“The findings in our cases and previous studies showed that MG and immune POF comorbidities were associated,” the researchers said. They noted, however, that the exact mechanisms connecting the conditions have yet to be figured out. They also pointed out that some typical POF treatments — specifically hormone replacement therapy with estrogen or progesterone — may aggravate MG or precipitate a crisis. That means that clinicians need to be careful treating patients who present with both disorders.
The researchers also noted that, in both cases, the patients’ first symptoms of MG were evident before they showed signs of POF. That suggests that, at least in some instances, “timely immunotherapy for MG may normalize POF,” they said.