Plasmapheresis

Updated: Jul 19, 2017
  • Author: Elliot Stieglitz, MD; Chief Editor: Emmanuel C Besa, MD  more...
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Overview

Background

Plasmapheresis is a term used to refer to a broad range of procedures in which extracorporeal separation of blood components results in a filtered plasma product. [1, 2] The filtering of plasma from whole blood can be accomplished via centrifugation or the use of semipermeable membranes. [3] Centrifugation takes advantage of the different specific gravities inherent to various blood products, such as red blood cells (RBCs), white blood cells (WBCs), platelets, and plasma. [4] Membrane plasma separation uses differences in particle size to filter plasma from the cellular components of blood. [3]

Traditionally, in the United States, most plasmapheresis is done with automated centrifuge-based technology. [5] In certain instances—in particular, in patients already undergoing hemodialysis—plasmapheresis can be carried out using semipermeable membranes to filter plasma. [4]

In therapeutic plasma exchange, using an automated centrifuge, filtered plasma is discarded and red blood cells along with replacement colloid such as donor plasma or albumin is returned to the patient. In membrane plasma filtration, secondary membrane plasma fractionation can selectively remove undesired macromolecules, which then allows return of the processed plasma to the patient instead of donor plasma or albumin. Examples of secondary membrane plasma fractionation include cascade filtration, [6] thermofiltration, cryofiltration, [7] and low-density lipoprotein pheresis.

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Indications

Plasmapheresis is currently used as a therapeutic modality in a wide array of conditions. [2, 8] Generally, it is used when a substance in the plasma, such as immunoglobulin, is acutely toxic and can be efficiently removed. Myriad conditions that fall into this category (including neurologic, hematologic, metabolic, dermatologic, rheumatologic, and renal diseases, as well as intoxications) can be treated with plasmapheresis.

The Apheresis Applications Committee of the American Society for Apheresis periodically evaluates potential indications for apheresis and categorizes them from I to IV in the basis of the available medical literature. The following are some of the indications, and their categorization, from the society’s guidelines. [2]

Category I (disorders for which apheresis is accepted as first-line therapy, either as a primary standalone treatment or in conjunction with other modes of treatment) are as follows:

  • Chronic inflammatory demyelinating polyneuropathy
  • Hyperviscosity in monoclonal gammopathies
  • Thrombotic thrombocytopenic purpura
  • Goodpasture syndrome (unless it is dialysis-dependent and there is no diffuse alveolar hemorrhage)
  • Hemolytic uremic syndrome (atypical, due to autoantibody to factor H)
  • Wilson disease, [9] fulminant

Category II (disorders for which apheresis is accepted as second-line therapy, either as a standalone treatment or in conjunction with other modes of treatment) are as follows:

  • Lambert-Eaton myasthenic syndrome
  • Multiple sclerosis (acute central nervous system demyelination disease unresponsive to steroids)
  • RBC alloimmunization in pregnancy
  • Mushroom poisoning
  • Acute disseminated encephalomyelitis
  • Hemolytic uremic syndrome (atypical, due to complement factor mutations)
  • Autoimmune hemolytic anemia (life-threatening cold agglutinin disease)
  • Systemic lupus erythematosus (severe)
  • Myeloma cast nephropathy

Category III (optimum role of apheresis therapy is not established; decision-making should be individualized) are as follows:

  • Posttransfusion purpura
  • Autoimmune hemolytic anemia (warm autoimmune hemolytic anemia)
  • Hypertriglyceridemic pancreatitis [10]
  • Thyroid storm

Category IV (disorders in which published evidence demonstrates or suggests apheresis to be ineffective or harmful; institutional review board [IRB] approval is desirable if apheresis treatment is undertaken in these circumstances) are as follows:

  • Stiff person syndrome
  • Hemolytic uremic syndrome (typical diarrhea-associated)
  • Systemic lupus erythematosus (nephritis)
  • Immune thrombocytopenia
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Contraindications

Plasmapheresis is contraindicated in the following patients:

  • Patients who cannot tolerate central line placement
  • Patients who are actively septic or are hemodynamically unstable
  • Patients who have allergies to fresh frozen plasma or albumin depending on the type of plasma exchange
  • Patients with heparin allergies should not receive heparin as an anticoagulant during plasmapheresis
  • Patients with hypocalcemia are at risk for worsening of their condition because citrate is commonly used to prevent clotting and can potentiate hypocalcemia
  • Patients taking angiotensin-converting enzyme (ACE) inhibitors are advised to stop taking the medication for at least 24 hours before starting plasmapheresis
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Technical Considerations

Terminology

Although the term plasmapheresis technically refers only to the removal of plasma, it is also widely used to encompass therapeutic plasma exchange in which a replacement product is transfused after removal of the plasma. [11]

As distinct from plasmapheresis, cytapheresis is the selective removal of red blood cells (RBCs), white blood cells (WBCs), or platelets and can be accomplished by using identical centrifuge-based equipment. Applications include the following:

  • Erythrocytapheresis (selective removal of RBCs) is used in conditions such as sickle cell disease or malarial infection, in which RBCs are selectively removed and replaced with donor erythrocytes
  • Leukapheresis (selective removal of WBCs) is used in conditions such as hyperleukocytosis, in which pathologically high number of white cells are present (as, for example, in leukemia); it can also be used to collect peripherally circulating stem cells that can then be infused in an autologous or allogeneic stem cell transplant
  • Platelet apheresis (selective removal of platelets) can be used in conditions of thrombocytosis (eg, polycythemia vera)

Complication prevention

Having all the equipment and medications required for the procedure readily available at the start in order to minimize complications is important. Sterile technique is advised in order to reduce the likelihood of infection.

Premedication with acetaminophen, diphenhydramine, and hydrocortisone are often given if the patient is to receive any blood product, including priming the tubing with packed red blood cells, in particular if a history exists of prior reaction to blood products. [12]

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