What are the possible mechanisms of action for plasmapheresis leading to clinical improvement?
There are two general mechanisms that may lead to improvement: (1) removal of pathologic substances or (2) replacement of a missing or abnormal plasma component (such as A Disintegrin And Metalloproteinase with a ThromboSpondin type 1 motif (ADAMTS-13) in thrombotic thrombocytopenic purpura [TTP]). The pathologic factors that can be removed by plasmapheresis are:
- • Auto-antibodies
- • Immune complexes
- • Cryoglobulins
- • Complement products
- • Lipoproteins
- • Protein-bound toxins
The success of plasmapheresis depends on the rate of production of the abnormal protein or antibody and the efficiency of removal with plasmapheresis. Plasmapheresis is most often utilized with other immunosuppressive strategies to decrease production and reduce inflammation. Other additional benefits may include reversal of impaired splenic function to remove immune complexes and improvement of macrophage and monocyte function.