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Plasmapheresis

Larry H. Bernstein, MD, FCAP, Curator

LPBI

Plasmapheresis

Author: Elliot Stieglitz, MD; Chief Editor: Emmanuel C Besa, MD

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 semipermeable membranes.[3] Centrifugation takes advantage of the different specific gravities inherent to various blood products such as red cells, white cells, 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 takes place using 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 for 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.

Plasmapheresis is currently used as a therapeutic modality in a wide array of conditions.[2] Generally, plasmapheresis is used when a substance in the plasma, such as immunoglobulin, is acutely toxic and can be efficiently removed. Myriad conditions fall under this category, including neurologic, hematologic, metabolic, dermatologic, rheumatologic, and renal diseases, as well as intoxications, that 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 based on the available medical literature. The following are some of the indications, and their categorization, from the society’s 2010 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 dialysis dependent and no diffuse alveolar hemorrhage)
  • Hemolytic uremic syndrome (atypical, due to autoantibody to factor H)
  • Wilson disease, 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)
  • Red cell 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:

  • Post-transfusion purpura
  • Autoimmune hemolytic anemia (warm autoimmune hemolytic anemia)
  • Hypertriglyceridemic pancreatitis
  • Thyroid storm

Category IV (disorders in which published evidence demonstrates or suggests apheresis to be ineffective or harmful; 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

Contraindications  

See the list below:

  • 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.

http://emedicine.medscape.com/article/1895577-overview#a4

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