When to start plasmapheresis in a patient with myasthenia gravis
In myasthenia gravis, antibodies bind to acetylcholinase receptors, preventing muscle contratctions.
At what point in the course of myasthenia gravis (MG) should plasmapheresis be considered as a viable treatment option?—STEVEN BRANDENBURG, PA-C, Germantown, Ohio
The weakness experienced in MG is attributable to a blockage of neuromuscular transmission caused by autoantibodies binding to acetylcholine receptors. There are four usual treatments for MG: (1) anticholinesterase agents, such as pyridostigmine (Mestinon); (2) chronic immunomodulating drugs (e.g., prednisone, azathioprine, cyclosporine); (3) rapid immunomodulating treatments (e.g., plasmapheresis, IV immune globulin [IVIG]); and (4) thymectomy. Plasmapheresis removes acetycholine receptor antibodies from the circulation, and improvement is usually seen within days, but this benefit usually lasts only three to four weeks. Plasmaphereses (IVIG therapy) is generally used for managing an acute myasthenic crisis or stabilizing patients before thymectomy.—JoAnn Deasy, PA-C, MPH (141-10)