Plasmapheresis

Plasmapheresis is an extracorporeal process in which blood is removed from the body and then separated into plasma and blood cells. The blood cells are then returned, and depending on the procedure, the plasma may be returned after purification (selective plasmapheresis) or replaced with donor plasma or albumin solution (nonselective plasmapheresis). Some of the techniques used for purification include immunoadsorption or filtration to selectively remove certain pathogenic blood components (e.g. autoantibodies). Plasmapheresis is used for collecting plasma donations or therapeutically, including for autoimmune (e.g., myasthenia gravis, Goodpasture syndrome, Guillain-Barré syndrome), hematologic (e.g., thrombotic thrombocytopenic purpura), metabolic (e.g., severe Wilson disease), and oncologic conditions (e.g., Waldenstrom macroglobulinemia) as well as intoxications (e.g., mushroom poisoning).

Definitions

• Apheresis: An extracorporeal process in which a patient's blood is passed through a machine that separates a particular component and returns the remaining components to the patient. Types include plasmapheresis, erythrocytapheresis, plateletpheresis, and leukapheresis.
• Plasmapheresis: a procedure in which plasma is separated from the whole blood
• Therapeutic plasmapheresis: plasmapheresis performed to remove harmful components of the individual's plasma (e.g., autoantibodies, toxins)

Procedure ^[1]

1. A patient is connected to the plasmapheresis machine via a system of tubes.
2. Blood is drawn from a patient.
3. Plasma is separated from other components by either of the following:
   • Filtration: blood is filtered via a semipermeable membrane
   • Centrifugation: centrifugal forces applied to the whole blood separate blood components into layers based on their density
4. Volume replacement is done in one of the following ways:
   • Selectively: The plasma is purified (e.g., with immunoadsorption or filtration) and returned back to the patient.
   • Nonselectively: The plasma is withdrawn and replaced with another solution (typically fresh frozen plasma or 5% albumin solution).

• Plasma donation
• As a first-line therapy ^[2]
  • Guillain-Barré syndrome
  • Goodpasture syndrome
  • Antiphospholipid syndrome
  • Myasthenia gravis
  • Thrombotic thrombocytopenic purpura
  • Waldenstrom macroglobulinemia
  • Fulminant Wilson disease
• As a second-line therapy ^[2]
  • Thyroid storm
  • Multiple sclerosis
  • Acute disseminated encephalomyelitis
  • Severe cold agglutinin disease
  • Myeloma cast nephropathy
  • Mushroom poisoning

• Venipuncture-related complications (e.g., thrombophlebitis)
• Bleeding (due to anticoagulation and depletion of clotting factors)
• Electrolyte abnormalities (most commonly hypocalcemia) ^[3]
• Allergic reactions (commonly due to albumin)
• Cardiovascular complications (e.g, hypotension)
• Transfusion-transmitted infections (e.g., HIV, hepatitis B, hepatitis C)

We list the most important complications. The selection is not exhaustive.