Plasmapheresis is a process in which the liquid part of the blood, or plasma, is separated from the blood cells. Typically, the plasma is replaced with another solution such as saline or albumin, or the plasma is treated and then returned to your body. If you’re sick, your plasma can contain antibodies that attack the immune system. A machine can be used to remove the affected plasma and replace it with good plasma or a plasma substitute. This is also known as plasma exchange. The process is similar to kidney dialysis. Plasmapheresis also can refer to the plasma donation process, where the plasma is removed and the blood cells are returned to your body.
What’s the purpose of plasmapheresis?
Plasmapheresis can be used to treat a variety of autoimmune disorders including:
- myasthenia gravis
- Guillain-Barre syndrome
- chronic inflammatory demyelinating polyneuropathy
- Lambert-Eaton myasthenic syndrome
It can also be used to treat certain complications of sickle cell disease, as well as certain forms of neuropathy.
In each of these disorders, the body has developed proteins called antibodies that are programmed to identify cells and destroy them. These antibodies are in plasma. Normally, these antibodies are directed at foreign cells that may harm the body, such as a virus.
In people with an autoimmune disease, however, antibodies will respond to cells inside the body that carry out important functions. For example, in multiple sclerosis, the body’s antibodies and immune cells will attack the protective covering of nerves. That eventually leads to impaired function of muscles. Plasmapheresis can stop this process by removing the plasma that contains antibodies and replacing it with new plasma.
In recent years, the therapy has increasingly been used to treat people who are critically ill with infections and other problems such as Wilson’s disease and thrombotic thrombocytopenic purpura. It has also been used to help people who have received an organ transplant to counter the effect of the body’s natural rejection process.