Autoimmune diseases occur when the immune system mistakenly attacks its own healthy tissues and organs. This self-attack is driven by autoantibodies, specific immune proteins that target the body’s own components. Specialized medical procedures remove these autoantibodies from the bloodstream to manage disease activity and alleviate symptoms.
Understanding the Procedure
One such specialized medical procedure is therapeutic plasma exchange, commonly known as plasmapheresis. This process is designed to remove harmful components, such as disease-causing autoantibodies, from the blood. It shares a conceptual similarity with kidney dialysis, yet its purpose differs; instead of filtering waste products, plasmapheresis separates the liquid portion of the blood, known as plasma, from the blood cells. This method directly reduces the concentration of problematic autoantibodies circulating in the body.
Mechanism of Antibody Removal
The process begins with blood being drawn from the patient, typically through an intravenous line placed in an arm or, for multiple treatments, a central venous catheter. This blood then travels to a machine that separates its components using either centrifugation or filtration. Centrifugation involves rapid spinning to separate components by density, while filtration passes blood through a membrane with pores large enough to allow plasma to pass through.
Once separated, the “diseased” plasma, which contains the autoantibodies, is collected and discarded. The remaining blood cells, including red blood cells, white blood cells, and platelets, are then combined with a replacement fluid like albumin or fresh frozen plasma. The reconstituted blood is returned to the patient’s body through a separate intravenous line. This entire circuit effectively reduces autoantibody levels, often removing 65% to 70% of disease-causing proteins in a single session.
When It Is Used
Therapeutic plasma exchange is typically employed in cases of severe or rapidly progressing autoimmune diseases where autoantibodies play a direct role in the disease process. It is often considered when other treatments, such as medications, may not be effective enough or require a longer time to show results. This procedure can provide a more immediate reduction in harmful autoantibody levels.
Conditions for which plasmapheresis is frequently used include Myasthenia Gravis, an autoimmune disorder affecting muscle weakness, and Guillain-Barré Syndrome, which causes rapid muscle weakness due to nerve damage. It is also used in certain forms of vasculitis, which involve inflammation of blood vessels, and some types of lupus or multiple sclerosis, particularly during acute, severe flare-ups. The decision to use plasmapheresis depends on the specific autoimmune condition, its severity, and the patient’s overall health status.
What to Expect During Treatment
Before a therapeutic plasma exchange session, healthcare providers will ensure appropriate venous access, which may involve placing a needle in an arm vein or, for longer courses of treatment, a central line catheter in a larger vein. Patients are typically positioned in a reclining chair or bed for the duration of the procedure. A nurse or technician monitors the patient throughout the session.
A single session generally lasts between two to four hours, with the exact time varying based on the patient’s body size and the volume of plasma to be exchanged. During the procedure, some individuals may experience mild sensations such as tingling around the lips or fingertips, lightheadedness, nausea, or a feeling of cold. These sensations are often temporary and closely monitored by the medical team. Patients usually need a series of sessions, often daily or every other day, for a few weeks to achieve the desired therapeutic effect. After a session, it is common to feel tired, and patients are typically advised to rest and stay hydrated.