Encyclopedia
Please note this is an old version of this entry, which may differ significantly from the current revision.
Subjects:
Critical Care Medicine
Therapeutic plasma exchange (TPE) is a treatment paradigm used to remove harmful molecules from the body. In short, it is a technique that employs a process that functions partially outside the body and involves the replacement of the patient’s plasma. It has been used in the ICU for a number of different disease states, for some as a first-line treatment modality and for others as a type of salvage therapy.
- plasmapheresis
- ICU
- TPE
1. Introduction
Therapeutic plasma exchange (TPE), also known as plasmapheresis, is an extracorporeal technique that replaces patients’ plasma to remove pathogenic molecules. The common targets for removal are autoimmune antibodies, donor-specific antibodies, excessive paraproteins, cytokines, and endogenous and exogenous toxins [1]. TPE has become a commonly used, life-saving standard therapy for various conditions in intensive care settings.
2. Mechanisms and Principles of Therapeutic Plasma Exchange (TPE)
During a TPE session, the patient’s blood is drawn a peripheral or central access site into the apheresis system. TPE is performed via two different major techniques: centrifugal separation and membrane separation [2]. In the centrifugal separation method, the blood is spun in an apheresis device and the different components are separated via specific gravity. In the membrane separation method, the blood crosses non-selective microporous membranes, which allow for the passage of molecules less than a certain weight and also allows for the retention of blood cells. The respective levels of efficacy of these two methods are comparable based on historical studies, although the centrifugal process was reported to be more time-efficient [3]. Notably, the membrane separation method is more commonly used in Japan and Germany, while the centrifugal separation method is dominant in the USA and the rest of Europe [4]. After the apheresis process, the blood is infused back into the patient along with healthy donor plasma or albumin (with or without normal saline).
Most TPE methods use albumin replacement to ensure less immunogenicity and improved safety. Certain hematological emergencies require replacement with plasma and cryoprecipitate to restore coagulation factors and normal coagulation function, such as thrombotic thrombocytopenic purpura (TTP), thrombotic microangiopathy (TMA) with factor H autoantibody, drug-induced TMA, and ANCA vasculitis-associated diffuse alveolar hemorrhage (DAH) [5].
TPE nonspecifically removes plasma molecules, including pathogenic molecules, normal coagulation factors, and immunoglobulin, which could put patients at higher risk of thrombosis, bleeding, infection, or allergic reaction (exclusively from plasma). Based on a single-center retrospective study in France, less than half of TPE sessions had at least one adverse effect, with hypocalcemia (19.6%) and hypotension (15.2%) being the most common; severe adverse effects only happened in 5.4% of patients [6]. Immunoadsorption (IA) was developed in the 1990s by using a specific plasma filter with bound antigens to target the immunoglobulin and preserve other plasma components. This approach could potentially minimize the risk of complication, and it is under investigation as a substitute for TPE in certain conditions [7,8].
ICU patients undergoing TPE can have multiple organ failure and require other extracorporeal supporting systems, such as intermittent hemodialysis (IHD), continuous renal replacement therapy (CRRT), and extracorporeal membrane oxygenation (ECMO). Such procedures could be performed sequentially or simultaneously via single or multiple access points. Systems could be combined in series, parallel, or hybrid mode [9].
3. Indications for Therapeutic Plasma Exchange in the ICU
Since 1986, the American Society for Apheresis (ASFA) has comprehensively reviewed the scientific evidence of the indications of therapeutic apheresis and issued detailed guidelines. The most recent ninth edition was published in early 2023 and highlighted 77 diseases with 119 indications for therapeutic plasma exchange [5]. There are 20 indications with TPE listed as a first-line treatment (ASFA category I) and 23 indications with TPE listed as a second-line treatment (ASFA category II) for various diseases (see Table 1). The ‘Kidney Disease: Improving Global Outcomes’ (KDIGO) group and American Academy of Neurology (AAN) also provide guidelines covering a few specific indications under their specialties [10,11]. The British Society for Hematology and the Japanese Society for Apheresis also issued guidelines reflecting the local experts’ consensus [12,13]. A great number of patients who require TPE are critically ill and will require intensive care monitoring. Guidelines have recommended individualized approaches based on the patient’s condition and following the local organizational policy based on resources and standard practice.
Table 1. Indications for therapeutic plasma exchange (TPE) (adapted from ASFA 2023 guidelines).
| System | Lines | Diagnosis | Specific Condition |
|---|---|---|---|
| Neurological disorders | First-line | Acute inflammatory demyelinating polyneuropathy | |
| Chronic acquired demyelinating polyneuropathies, IgG/IgA/IgM-related | |||
| Chronic inflammatory demyelinating polyradiculoneuropathy | |||
| Myasthenia gravis | Acute, short-term treatment | ||
| N-methyl-D-aspartate receptor antibody encephalitis | |||
| Second-line | Lambert–Eaton myasthenic syndrome | ||
| Multiple sclerosis | Acute attack/relapse; long-term treatment | ||
| Neuromyelitis optical spectrum disorder | Acute attack/relapse | ||
| Pediatric autoimmune neuropsychiatric disorders | PANDAS/PANS, exacerbation | ||
| Steroid-responsive encephalopathy associated with autoimmune thyroiditis | |||
| Hematological disorders | First-line | Catastrophic antiphospholipid syndrome | |
| Hyperviscosity in hypergammaglobulinemia | Prophylaxis for rituximab; symptomatic hyperviscosity syndrome | ||
| Thrombotic microangiopathy, complement-mediated | Factor H autoantibody-related only | ||
| Thrombotic microangiopathy, drug-induced | Ticlopidine-related only | ||
| Thrombotic microangiopathy, thrombotic thrombocytopenic purpura | |||
| Second-line | Lambert–Eaton myasthenic syndrome | ||
| Multiple sclerosis | Acute attack/relapse; long-term treatment | ||
| Neuromyelitis optical spectrum disorder | Acute attack/relapse | ||
| Pediatric autoimmune neuropsychiatric disorders | PANDAS/PANS, exacerbation | ||
| Steroid-responsive encephalopathy associated with autoimmune thyroiditis | |||
| Transplantation-associated complications | First-line | Transplantation, kidney, ABO-compatible | Antibody-mediated rejection; Desensitization/prophylaxis, living donor |
| Transplantation, kidney, ABO-incompatible | Desensitization, living donor | ||
| Transplantation, liver | Desensitization, ABOi, living donor | ||
| Second-line | Transplantation, heart | Desensitization; rejection prophylaxis | |
| Transplantation, hematopoietic stem cell, ABO-incompatible | Major ABO incompatible: HPC(M); HPC(A) | ||
| Transplantation, kidney, ABO-incompatible | Antibody-mediated rejection | ||
| Renal disorders | First-line | Antiglomerular basement membrane disease | Diffuse alveolar hemorrhage; dialysis-independent disease |
| Focal segmental glomerulosclerosis | Recurrent in kidney transplant | ||
| Hepatic disorders | First-line | Acute liver failure (TPE-HV preferred over regular TPE) | Other than acute fatty liver of pregnancy |
| Wilson disease, fulminant | |||
| Other Systems | Second-line | Systemic lupus erythematosus | |
| Thyroid storm | |||
| Familial hypercholesterolemia | |||
| Phytanic acid storage disease | |||
| Hepatitis B related polyarteritis nodosa vasculitis | |||
| Voltage-gated potassium channel antibody-related diseases | |||
| Mushroom poisoning |
PANDAS, pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections; PANS, pediatric acute-onset neuropsychiatric syndrome; HPC(M), hematopoietic progenitors from bone marrow; HPC(A), allogeneic hematopoietic progenitor cell; TPE-HV, therapeutic plasma exchange—high volume.
The optimal timing of initiation of TPE varies significantly by condition, from emergent use (within 4–6 h) to urgent use (within 24 h) to planned routine treatment. Intensivists should carefully weigh the risks and benefits of TPE based on the clinical context. TPE should be initiated as early as possible in combination with other treatment modalities for organ- or life-threatening conditions, such as TTP, catastrophic antiphospholipid syndrome (CAPS), mushroom intoxication, symptomatic hyperviscosity syndrome, severe myasthenia gravis, fulminant Wilson’s disease, and diffuse alveolar hemorrhage caused by autoimmune disease [14,15,16,17]. For devastating neurological conditions, such as Guillan-Barre/acute inflammatory demyelinating polyneuropathy and N-methyl-D-aspartate receptor antibody encephalitis, early initiation to stop ongoing injury processes could prevent permanent damage to the neurological system and may lead to better outcomes [18].
Since the COVID-19 pandemic, TPE has also been investigated for severe COVID-19 infection in the hope of removing excessive cytokines to alleviate significant inflammation and cytokine release syndrome. There are retrospective studies and a pilot randomized controlled trial showing potential survival benefits in severely ill patients [19,20,21]. However, this topic remains controversial. The continued fluctuation of epidemics calls for more scientific evidence regarding TPE use in critical COVID-19 patients.
This entry is adapted from the peer-reviewed paper 10.3390/medicina59122152
This entry is offline, you can click here to edit this entry!
