Plasmapheresis in the treatment of autoimmune disorders

As we all know, our immune system defends our bodies against foreign cells that infiltrate our bodies, such as viruses, and cause harm to our health. The body's immune system wrongly turns against itself in autoimmune illnesses, attacking its own tissues. Some of the specialized cells engaged in this process can directly assault tissues, while others make antibodies that circulate in the blood and carry out the attack. Antibodies are proteins that our bodies make that are programmed to recognize and destroy certain cells. Autoantibodies are antibodies that target the tissues of your own body.

The pharmacological strategy, which employs medicine to inhibit the immune system or reduce tissue inflammation, is the most prevalent approach in the treatment of autoimmune illnesses. However, all immunosuppressive drugs have major adverse effects when used in large dosages or for an extended period of time.

Researchers devised a novel strategy to treating autoimmune disorders in the 1970s, with backing from the Muscular Dystrophy Association (MDA). Instead of attempting to modify the body's immunity just through medicine, the researchers thought that mechanical removal of autoantibodies from the bloodstream would have a dialysis-like effect (so-called "artificial kidney"), which has been employed effectively in renal failure. The method of such blood "cleaning" became known as plasmapheresis, which means plasma separation from blood and is also known as "plasma exchange."


How can plasmapheresis aid in the treatment of autoimmune diseases?

Plasmapheresis is the process of separating the fluid portion of blood (i.e. plasma) from blood cells using a device known as a "cell separator." Separators operate by either passing the blood at high speeds to separate the cells from the fluid or by passing the blood through the tiniest membranes, through which only the liquid component of the blood may pass.

Blood cells are returned to the patient's bloodstream, whereas isolated plasma containing dissolved antibodies (and, in the case of an autoimmune patient, autoantibodies) is discarded and replaced by other fluids such as saline or albumin, or is removed from the blood and then returned to the patient.

The primary mechanism of therapeutic action is thought to be the elimination of circulating autoantibodies, immune complexes, cytokines (cells also implicated in the body's particular immunological response), and other mediators of inflammation.

Inclusion of plasma exchange in the treatment of autoimmune illnesses also allowed for large reductions in medication doses controlling immunological processes or inflammations, reducing the negative impact on the body caused by drug side effects.

Plasmapheresis is now frequently used to treat myasthenia gravis, Lambert-Eaton syndrome, Guillain-Barré syndrome, and chronic demyelinating polyneuropathy. However, its usefulness in other disorders such as multiple sclerosis, polymyositis, and dermatomyositis is currently being investigated.

The American Society of Apheresis publishes frequently updated indications for plasma exchange in treatment based on validated medical practices. As of now, the organization has published two lines of practically proved data supporting plasmapheresis usefulness in diseases.

Category I indications for therapeutic plasma exchange (first-line treatment based on good scientific evidence):


   Neurology :

  • Acute Guillain-Barré syndrome
  • Chronic inflammatory demyelinating polyneuropathy
  • Myasthenia Gravis
  • Paraproteinaemia-related polyneuropathy
  • PANDASa (Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection)

    Haematology:

  • Thrombotic thrombocytopenic purpura 
  • Atypical hemolytic uremia (autoantibody to factor H)
  • Syndromes of hyperviscosity (paraproteinaemias)
  • Cryoglobulinaemia with severe symptoms


   Renal: 

  • Goodpasture's disease (anti-glomerular basement membrane antibodies)
  • Rapidly developing glomerulonephritis caused by antineutrophil cytoplasmic antibody (ANCA).
  • The condition is known as recurrent focal segmental glomerular sclerosis.
  • Renal transplant rejection caused by antibodies


Metabolic:

Category II indications for therapeutic plasma exchange (established second-line therapy, required support by additional treatments): 

  • Familial hypercholesterolaemia (homozygous) 
  • Fulminant Wilson's disease