Myasthenia gravis (MG) is usually treated with medications like immunosuppressants, corticosteroids, and cholinesterase inhibitors. However, if medications aren’t working or if your symptoms are worsening, your healthcare provider might recommend treating your blood directly. Plasmapheresis is a broad term for procedures, including therapeutic plasma exchange, that clean parts of your blood to provide short-term symptom relief.

In this article, we’ll explain how this treatment works and when it’s used for people with MG.

MG Caused by Antibodies Gone Wrong

MG is an autoimmune disorder. Normally, the immune system protects you from getting sick. It creates cells called antibodies that kill intruders, like bacteria and viruses. But when the immune system isn’t working properly, it can create antibodies that attack your own tissues instead of bacteria and viruses.

In MG, the body’s immune system produces antibodies that attack the connection points between nerves and muscles, known as the neuromuscular junction. Normally, muscles contract when they receive signals from the brain, which are carried by chemicals called neurotransmitters. In MG, the antibodies interfere with these signals, making it harder for muscles to respond. This leads to muscle weakness and fatigue.

One important neurotransmitter is called acetylcholine. It’s absorbed by receptor sites located between nerves and muscles. When enough of these acetylcholine receptor sites are damaged by antibodies, the muscles become unable to properly receive messages from the brain, causing muscle weakness.

Antibodies can also cause MG by attacking a protein called muscle-specific receptor tyrosine kinase, which helps build receptor sites, and another protein called lipoprotein-related protein 4 (LRP4).

Plasmapheresis Removes Bad Antibodies

Blood is made up of four main parts: red blood cells, white blood cells, platelets, and plasma.

Plasma is a mixture of water, proteins, and salt. It carries the other blood cells through your blood vessels. Plasma also contains antibodies. Some of these antibodies are healthy, but others — like the antibodies that cause MG — can be harmful.

Plasmapheresis works by removing these harmful antibodies from your plasma. During plasmapheresis, blood is taken from your body and put into a machine. The machine removes the plasma, along with the harmful antibodies. It then replaces the plasma with healthy fluid, and the cleaned blood is returned to your body.

Plasmapheresis is also used to treat harmful antibodies in other autoimmune diseases, like multiple sclerosis and Guillain-Barré syndrome.

What To Expect During Plasmapheresis

Plasmapheresis is often done in a hospital, either as part of an inpatient stay or as an outpatient procedure.

During plasmapheresis treatment, you’ll sit in a reclining chair or bed. A healthcare provider will insert a needle or IV line into a vein in your arm or into a catheter. The plasmapheresis machine will slowly remove your blood and separate the plasma. Plasma, once separated from the blood cells, looks like yellow liquid. After removal, the plasma is thrown out in its bag, along with any MG antibodies.

Healthcare providers will then replace the plasma with a replacement fluid containing a protein called albumin, injecting it back into your body. This replacement fluid is a copy of your existing plasma but doesn’t contain any harmful antibodies.

The plasmapheresis process usually takes two to three hours, depending on your height, weight, and blood health. During the procedure, you may feel cold, dizzy, or nauseous. If you feel unwell, a nurse or technician can adjust your position or pause the procedure briefly.

After plasmapheresis, you may feel tired. If possible, bring a friend or family member to help you get home, especially if you need to drive. Rest for 24 hours after finishing plasmapheresis and avoid alcohol or heavy exercise.

Plasmapheresis usually doesn’t cause any serious side effects. However, it can lead to certain complications.

Hypocalcemia

Plasmapheresis can remove too much calcium from the blood, causing hypocalcemia (low calcium levels in the blood). If this happens, your healthcare provider will give you calcium through an IV. Eating calcium-rich foods like milk or cheese before undergoing plasmapheresis can optimize treatment.

Low Blood Pressure

Plasmapheresis can lead to hypotension (low blood pressure) . Your healthcare provider can treat this with transfusions of extra fluids.

Hypothermia

Your body temperature may drop after plasmapheresis, causing hypothermia (a drop in body temperature). This is treated by pumping warm fluids into your body through an IV.

Most people with MG undergo plasmapheresis every day or three times a week for several weeks.

More frequent treatment may work better. One study found that people having a myasthenic crisis spent less time in the hospital if they received plasmapheresis daily instead of every other day. Additionally, people admitted to the hospital for MG recovered faster if they started plasmapheresis within two days of admission.

When Is Plasmapheresis Used for MG?

Plasmapheresis is used for people experiencing a cholinergic crisis, which involves severe muscle weakness that makes breathing or swallowing difficult and requires fast treatment. It also helps during serious flare-ups of myasthenia gravis when quick relief is needed. Doctors may use plasmapheresis before a thymectomy (surgery to remove the thymus) in high-risk people with MG. It can also be a treatment option while waiting for slower-acting medicines to start working. Plasmapheresis is usually used when intravenous immune globulin (IVIG) doesn’t work or can’t be given.

Plasmapheresis and MG Symptoms

While undergoing plasmapheresis, your healthcare provider will likely prescribe steroids and other immunosuppressant drugs. These medications will help prevent your body from creating more harmful antibodies. You’ll usually need to keep taking these drugs for a few months after stopping plasmapheresis. Plasmapheresis can make other medications more effective.

Plasmapheresis can provide quick relief for MG symptoms. You will probably feel improvements in muscle weakness in a few days. However, these effects are short-term and usually last for a few months.

Even though plasmapheresis does not have long-term effects, it can be more effective than some other treatments for MG. One analysis found that people with acute MG or those undergoing a thymectomy were more likely to respond positively to plasmapheresis than to a similar treatment with IVIG.

Talk With Others Who Understand

MGteam is the social network for people with myasthenia gravis and their loved ones. Members come together to ask questions, give advice, and share their stories with others who understand life with myasthenia gravis.

Have you undergone plasmapheresis for MG? Share your experience in the comments below, or start a conversation by posting on your Activities page.