Plasmapheresis is a medical procedure that involves the removal of plasma from the blood. Plasma is the liquid component of blood that carries cells, nutrients, and waste products. During the procedure, blood is drawn from a patient, and a machine separates the plasma from the blood cells. The blood cells are then mixed with a replacement solution and returned to the patient. This treatment is often used to manage various autoimmune diseases, such as myasthenia gravis and Guillain-Barré syndrome. By removing harmful antibodies from the plasma, plasmapheresis can help reduce symptoms and improve the patient's condition.