- Plasmapheresis is a medical procedure in which the plasma, or liquid component of blood, is separated from the blood cells, removed, and either discarded or treated before being returned to the patient.
- The term is often used interchangeably with therapeutic plasma exchange (TPE), but in strict medical usage, plasmapheresis can refer to any removal of plasma, regardless of whether it is replaced, while plasma exchange specifically involves replacing the removed plasma with a substitute fluid such as albumin solution, saline, or donor plasma.
- The core principle of plasmapheresis is that many disease processes involve harmful substances circulating in the plasma—such as autoantibodies, immune complexes, toxins, or abnormal proteins—and their removal can help reduce disease activity.
- The procedure is carried out using specialized equipment that separates plasma from the cellular components of blood—red blood cells, white blood cells, and platelets—through centrifugation or membrane filtration.
- In centrifugation-based systems, blood is spun at high speeds, allowing the lighter plasma to be separated from the denser cellular elements.
- In membrane filtration systems, the blood passes through a filter with pores that permit plasma proteins and solutes to pass while retaining the cellular elements.
- Once the plasma is separated, it can be discarded and replaced with a substitute fluid (in plasma exchange) or processed and returned to the patient in modified form, depending on the therapeutic goal.
- Plasmapheresis is used to treat a variety of conditions, especially those in which the plasma contains pathogenic factors. It is a cornerstone therapy for autoimmune and immune-mediated diseases such as thrombotic thrombocytopenic purpura (TTP), myasthenia gravis, Guillain–Barré syndrome, and neuromyelitis optica. In these conditions, the removal of autoantibodies or immune complexes can quickly reduce disease activity and prevent organ damage. It is also employed in certain hematologic and metabolic conditions, such as hyperviscosity syndromes in Waldenström macroglobulinemia, familial hypercholesterolemia, or antibody-mediated rejection in organ transplantation.
- The frequency and duration of plasmapheresis treatments vary depending on the disease and clinical response. In acute conditions like TTP, daily sessions are common until laboratory markers and symptoms improve. In chronic or relapsing diseases, sessions may be spaced over weeks or months. Each procedure typically removes 1–1.5 times the patient’s plasma volume, significantly lowering the levels of the targeted pathogenic factor, though repeated treatments are often necessary since these molecules may be continuously produced by the body.
- Although generally safe, plasmapheresis is an invasive therapy that carries certain risks. Potential complications include hypotension, allergic or transfusion-related reactions (especially when donor plasma is used), electrolyte imbalances such as hypocalcemia from citrate anticoagulation, and increased susceptibility to infection from central venous catheter use. Because plasmapheresis can also remove beneficial plasma components like clotting factors and immunoglobulins, patients may experience transient coagulopathy or reduced immune protection, which are monitored closely during treatment.
- Plasmapheresis remains a valuable therapeutic tool in modern medicine because of its ability to rapidly reduce circulating pathogenic substances in the plasma. Unlike many pharmacologic treatments that take time to suppress disease activity, plasmapheresis can provide immediate benefits in severe or rapidly progressive conditions. Advances in apheresis technology have improved the safety, efficiency, and accessibility of this procedure, expanding its role in treating an ever-growing list of immune, hematologic, and metabolic disorders.
