Myasthenia gravis, a neuromuscular condition in which patients must endure fluctuating degrees of debilitating fatigue and weakness, is a chronic autoimmune disease affecting about 20 people in every 100,000 in the United States. A retrospective observational study led by Dr. Harold Atkins at the University of Ottawa in Ontario, Canada, published in JAMA Neurology, has shown that replacing the lymphocytes of patients with severe persistent myasthenia gravis with those generated by their own stem cells can help achieve long-term remission from the disease.
The study, although small (consisting of only seven patients), has shown promising results in terms of a stable and durable remission, in some instances lasting longer than a decade, following an autologous hematopoietic stem cell transplant (HSCT) procedure. Patients reportedly achieved complete remission, with no further need for drug therapy from approximately 2 to 13 years, following treatment with autologous HSCT combined with high-dose chemotherapy and anti-thymocyte globulin.
Currently, the procedure can be performed on a select population of patients who meet strict criteria to ensure that the benefits outweigh the risks. The widespread use of this therapy requires further testing; as of now, it can only be performed at institutions with a lot of experience in treating this condition.
During this particular study, there were no deaths from myasthenia gravis or the treatment itself, but this is not always the case. At institutions with inadequate infrastructure or insufficient expertise, investigators report HSCT-associated mortality ranging from 6 to 8 percent. This percentage falls to between 1 and 5 percent when considering smaller studies where the patient selection was more careful and supportive care was better. Researchers warn that the use of autologous HSCT for myasthenia gravis outside specialized medical centers with extensive expertise in the disease is not recommended.
Dr. Daniel Drachman of the Johns Hopkins School of Medicine concurs that the study is proof of the underlying principle that autologous HSCT is a promising treatment for myasthenia gravis. He does urge, however, a careful assessment of disease severity and response to other immunologic treatments before recommending HSCT to a patient. Dr. Drachman also raises a question about whether the results are truly permanent or simply represent an elimination of autoantibodies and auto-reactive cells in patients who were refractory to conventional therapies.
The study retrospectively looked at patients who underwent autologous HSCT over a 14-year period between 2001 and 2014 at Ottawa Hospital. The data analysis, completed in 2015, revealed that all the study subjects had electromyographic and clinical evidence of the disease with severe debilitating symptoms as defined by the Myasthenia Gravis Foundation of America (MGFA). Of the seven patients, six were female (the disease is more common in men than women), and the average age of the patients was 37 (myasthenia gravis typically presents itself to women in their 30s and after 50 in men).
It is estimated that the therapy will allow conventional agents used for the treatment of myasthenia gravis, such as CellCept (mycophenolate) or Imuran (azathioprine), to work more effectively when combined with autologous HSCT. The study offers hope to patients battling severe weakness and fatigue due to myasthenia gravis of a possible long-term drug-free remission from this crippling disease.