In order to provide guidelines for the use of therapeutic apheresis the Apheresis Applications Committee of American Society for Apheresis (ASFA) has developed evidence based guidelines for the use of therapeutic apheresis2. These guidelines include indication categories based on the existence of published clinical studies that demonstrate the efficacy or ineffectiveness of therapeutic apheresis in the treatment of a wide range of diseases and disorders.
Refer to the Seventh Special Edition of the Journal of Clinical Apheresis for a discussion of the specific diseases listed in each of these categories.
Category I neurologic diseases include2:
The most common use of TPE is for the treatment of autoimmune or immune mediated diseases or disorders. TPE is used to remove monoclonal immunoglobulins, paraproteins, autoimmune antibodies and antigen-antibody complexes.
The degree to which TPE is successful will depend on the presence or movement of antibody in the intravascular space.
Treatment for autoimmune disease attempts to suppress the abnormal immune response and/or remove the factors causing the disorder.
This may be done with drugs, such as cytoxan or prednisone, surgery to remove the involved organ as in the case of myasthenia gravis (thymus), or a combination of drugs and therapeutic plasma exchange.
TPE is considered when removing the offending antibody or immune complex results in an improvement in symptoms. Large quantities of plasma can be removed quickly and safely and replenished with the desired protein replacement fluid.
Combining plasma exchange with drug therapy can reduce antibody levels which may prevent further destruction of the involved organ or system.
During a TPE procedure, plasma is separated from other blood components, removed and replaced with an appropriate replacement fluid. Disease mediators circulating in the patient’s plasma are removed as well. The type of disease mediator present and the patient’s clinical response to TPE depends on the disease or disorder being treated.
TPE can be used to remove or decrease the level of circulating antibodies, antigen-antibody complexes, abnormal plasma proteins, cholesterol, metabolic waste products, and plasma bound poisons or drugs. Decreasing the level of disease mediator in the patient’s plasma can relieve or eliminate symptoms or prevent further destruction of the involved organ or system but it is generally not curative. TPE is most often used as an adjunct in combination with drug therapy or surgery.
To perform a TPE procedure the patient is connected to a centrifugal separation device such as the Spectra Optia® Apheresis System pictured in the slide.
A single use disposable tubing set is used for each apheresis procedure. Pumps draw patient blood into the centrifuge of the apheresis device. Plasma and cellular components of the blood have different specific gravities. Centrifugal force separates the different components of the blood and pumps the desired components to a bag while returning the remaining components to the patient. In a TPE procedure the plasma portion of the blood is separated from the cellular components. The plasma is removed to a waste bag and discarded. The cellular components of the blood are mixed with replacement fluid and returned to the patient. At the completion of the procedure, patient blood remaining in the device is returned to the patient during a short process called “Rinseback”.
The apheresis device automatically controls centrifuge speed and pump flow rates and offers easy to read screens which allow the procedure to be customized for your patient. The Optia device’s extracorporeal blood volume is never more than 185 mL and is often lower. Replacement fluid is given to the patient as plasma is removed to maintain the hemodynamic stability of the patient.