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Frequently Asked Questions 


What is plasmapharesis? What should I expect?




Plasmapheresis is a medical procedure designed to remove some plasma from the blood. During a plasma exchange, unhealthy plasma is swapped for healthy plasma or a plasma substitute, before the blood is returned to the body.

The blood vessels contain plasma. It is a fluid made up of blood cells, platelets, and essential nutrients. During plasmapheresis, blood is removed and separated into these parts by a machine. Plasmapheresis can also refer to when plasma is removed from the body to be donated. Pheresis, or apheresis, describes any process that removes the blood, filters and retains elements of it, then returns the blood to the body. Platelets, red blood cells, white blood cells, or plasma may be separated. The procedure is performed using a machine that removes small amounts of blood at a time.

There are two ways to separate the components of blood:

  • Centrifugation. This process spins the blood, which divides it according to the density of the parts.
  • Filtration. This involves passing the blood through a filter to separate plasma.

During a plasma exchange, the machine will dispose of unhealthy plasma and replace it with healthy plasma from a donor. Unhealthy plasma can also be replaced with saline, albumin, or a combination of the two. A plasma exchange can help to treat autoimmune encephalitis.  A plasma exchange can help to alleviate symptoms of AE by removing harmful substances from the blood. If a person has an autoimmune condition, a plasma exchange may also prevent the body from producing more harmful antibodies.

The procedure is usually one element of a treatment plan, which may include Rituxan (Rituximab), Actemra (tocilizumab), bortezomib, or Cyclophosphamide (Cytoxan). Repeated plasma exchanges may be necessary.


How to Prepare


A person can eat and drink normally before and even during plasmapheresis. Wearing loose clothing can help a person to stay comfortable. Use the bathroom before the process begins.

An individual will first undergo tests to determine:

  • blood pressure
  • pulse
  • temperature
  • oxygen levels

The results will help a doctor to set up the machine and monitor any changes that occur during the procedure.


What to Expect


A medical professional will perform plasmapheresis, usually in a hospital but sometimes in a private clinic. A local anesthetic will numb the affected area, and the procedure should not cause pain. The doctor will then insert a small tube into a vein in the arm or the groin. The tube will bring blood to the machine, which will collect it, treat it, and return it to the body. Plasma exchange takes between 2 and 4 hours. A person will need to remain as still as possible to help the blood to flow smoothly. It may help to watch television or read as a distraction. A medical professional will be present and check for side effects throughout the process. After the plasma exchange is complete, the machine will be disconnected, and new blood tests will be performed.


Risks and Side Effects


A person may have an allergic reaction to donated plasma, but several medications can reduce the risk. A doctor may recommend these medications before the procedure. During the donation process, plasma is screened for bacteria or disease. The risk of getting an illness from donated plasma is very low.

A plasma exchange can alter the balance of fluids in the body for a short time. A person may feel breathless or have cold hands and feet during or after the procedure. If this happens, a medical professional may pause the process to allow for recovery. A plasma exchange can also cause temporary low blood pressure and, in rare cases, shock. Plasmapheresis can reduce immunity to disease. This is usually temporary. However, for a time, the donor may become ill more easily. Wash the hands frequently and avoid being around anyone who is unwell.

Recovery is usually quick. However, they may feel tired. Get plenty of rest and avoid driving or exercise. If the patient feels unwell or experiences bleeding after leaving the hospital, they should contact their doctor.

Brian Weinshenker, M.D., a Mayo Clinic neurologist, describes the process of plasma exchange in treatment of multiple sclerosis or neuromyelitis optica at Mayo Clinic. (This is also used for AE). 

Our website is not a substitute for independent professional medical advice. Nothing contained on our website is intended to be used as medical advice. No content is intended to be used to diagnose, treat, cure or prevent any disease, nor should it be used for therapeutic purposes or as a substitute for your own health professional's advice. Although THE INTERNATIONAL AUTOIMMUNE ENCEPHALITIS SOCIETY  provides a great deal of information about AUTOIMMUNE ENCEPHALITIS, all content is provided for informational purposes only. The International Autoimmune Encephalitis Society  cannot provide medical advice.

International Autoimmune Encephalitis Society is a charitable non-profit 501(c)(3) organization founded in 2016 by Tabitha Andrews Orth, Gene Desotell and Anji Hogan-Fesler. Tax ID# 81-3752344. Donations raised directly supports research, patients, families and caregivers impacted by autoimmune encephalitis and to educating healthcare communities around the world. Financial statement will be made available upon request.

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