Therapeutic Plasma Exchange (TPE) is a patient treatment during which a large volume of the patient’s plasma is separated from the cellular components of the blood, removed, and replaced with appropriate fluids. TPE is performed to remove antibodies, immune complexes or other toxic substances circulating in the plasma.
What Is Therapeutic Plasma Exchange (TPE)?
Therapeutic Plasma Exchange (TPE) is a mode of treatment currently performed for a number of disease conditions.
What Does TPE Do?
Therapeutic plasma exchange (or TPE), is a patient treatment during which a large volume of the patient’s plasma is separated from the cellular components of the blood, removed, and replaced with appropriate fluids. TPE is performed to remove antibodies, immune complexes or other toxic substances circulating in the plasma.
Therapeutic plasma exchange is considered a non-specific therapy since it removes all plasma constituents, not just those causing symptoms.
In order for TPE to be a successful therapy, a disease or disorder must be caused by a disease mediator that can be efficiently removed with the plasma to an extent that reduces symptoms. Many of the diseases for which TPE is considered fall under the specialty areas of renal and metabolic diseases, hematologic diseases and neurologic disorders.
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.
How Is TPE Administered?
Therapeutic plasma exchange is usually done as a dual needle procedure. There are many different types of access. The type of access for patient will depend on the disease the patient has and the number and frequency of procedures.
Peripheral veins can be used for the procedure – assuming the patient has adequate peripheral veins and is able to squeeze. If peripheral access is being considered the patient’s veins should be evaluated prior to the procedure by an apheresis specialist. A large vein in the antecubital fossa is usually used to draw blood from the patient. During the procedure a pressure cuff is placed above the draw site and the patient will be asked to squeeze a hand grip intermittently throughout the procedure. A vein in the other arm is used to return blood to the patient. A smaller vein can be used for return and may be a vein in the lower forearm or hand for patient comfort during the procedure.
Apheresis staff trained in phlebotomy place peripheral lines prior to each procedure. A bandage is placed over the needle site for several hours after the procedure to prevent bleeding and bruising. If the patient has poor veins or has a neurologic disease impairing his ability to squeeze, peripheral access may not be ideal.
Dual lumen catheters can be placed in the femoral vein, or a central vein, such as the subclavian or intra-jugular (IJ) vein.
What is Frequency of TPE procedure?
The frequency of the procedures may be disease specific. Large proteins and immunoglobulins like IgM tend to stay in the intravascular space and are effectively removed by TPE. Procedures may be needed less frequently for IgM removal.
IgG antibodies move freely between the intravascular and extravascular space and may require more frequent treatments to reduce levels of disease mediator. Following a procedure, IgG antibodies re-equilibrate rapidly . This is sometimes known as a rebound effect.
What Are the Benefits of TPE?
Patient condition improves once the disease mediator is removed from circulation.
What Are the Risks of TPE?
Therapeutic plasma exchange procedures are generally well tolerated by the patient. Adverse reactions do, however occur and plans need to be in place for treating the patient in the event of an adverse reaction. Chilling, hypotension and hypocalcemia are the more common side effects of TPE procedures. Problems with the vascular access device used may occur and alternative vascular access options may need to be explored. Allergic reactions are uncommon, but can occur.
How Does a Patient Prepare For TPE?
Make sure you have a nutritious meal before undergoing treatment or donating.