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Evidence‐based approaches

Rationale

Apheresis is used for a number of donor and therapeutic purposes. A therapeutic procedure is when a blood component is removed from a patient to decrease the number of defective cells or deplete a disease mediator (Schwartz et al. [101]). A donor procedure is when a blood component (e.g. stem cells, lymphocytes, platelets) is removed to be used for therapeutic purposes (e.g. peripheral blood stem cell transplant, donor lymphocyte infusion, platelet transfusion).

Indications

The American Society for Apheresis (ASFA) Applications Committee reviews and categorizes the indications for therapeutic apheresis every 7 years. It aims to provide uniformity, is as evidence‐based as possible and provides comprehensive information which could be shared with patients and clinical services requesting the use of therapeutic apheresis (Schwartz et al. [101]). Some apheresis applications and indications are outlined in Table 21.5.

Table 21.5 Apheresis applications and indications

Applications	Indications
Therapeutic apheresis
Plasma exchange:
Removal of a patient's own plasma and replacement with appropriate fluids, for example albumin, FFP. This is in order to remove disease mediators including: alloantibodies autoimmune antibodies antigen–antibody complexes abnormal or increased amounts of plasma protein very high cholesterol levels high levels of plasma metabolic waste products plasma‐bound poisons or drugs	Thrombotic thrombocytopenia purpura (TTP) Guillain–Barré syndrome Myasthenia gravis
Red blood cell exchange:
Removal of large volumes of patient red blood cells and replacement with normal donor red blood cells	Sickle cell disease Malaria Babesiosis
Cellular depletion:
Rapid removal of greatly elevated numbers of cells from the intravascular space. Decreases the risk associated with vascular stasis, for example: White blood cell depletion Platelet depletion	Symptomatic leucocytosis in, for example, a patient newly diagnosed with acute myeloid leukaemia Symptomatic thrombocytosis in a patient with thrombophilia
Photopheresis:
Use of apheresis technology, light‐activated drugs and ultraviolet light to modulate lymphocyte activity	Cutaneous T cell lymphoma Pemphigus vulgaris Chronic graft‐versus‐host disease Acute and chronic graft rejection
Immunoadsorption:
Removal of a disease mediator from the patient's plasma and the subsequent return of the treated plasma to the patient	Immune thrombocytopenic purpura (ITP) Rheumatoid arthritis Platelet refractoriness Haemolytic uraemic syndrome
Dendritic cell collection:
Removal of dendritic cells in order to manipulate them in vitro by providing them with tumour antigen so that they are capable of activating T lymphocytes to fight malignancy	Prostate cancer Melanoma Multiple myeloma Small cell lung cancer Renal cell carcinoma Breast cancer
LDL apheresis:
Selective removal of LDL cholesterol from a patient's plasma through secondary processing	Familial hypercholesterolaemia unresponsive to drug therapy
Donor apheresis
Peripheral blood stem cell collection:
White cell procedure to collect haematopoietic stem cells. The collected stem cells may be used fresh or cryopreserved for both malignant and non‐malignant conditions	Autologous stem cell collection (patient's own stem cells) Allogeneic stem cell collection (collected from an HLA‐matched related or unrelated donor) Syngeneic stem cell collection (collected from the patient's identical twin) Haploidentical stem cell collection (collected from either the mother or father of the patient)
Granulocyte collection:
White cell procedure to collect granulocytes (neutrophils) from suitable donors	Transfuse to neutropenic patients in order to provide adequate numbers of functional neutrophils to fight bacterial, fungal or yeast infections
Lymphocyte collection:
White cell procedure to collect lymphocytes from a related or unrelated donor for a patient following an allogeneic stem cell transplant (the donor of the graft cells is also the donor of the lymphocytes)	Post allogeneic stem cell transplantation in the event of malignancy relapse Non‐myeloablative allogeneic stem cell transplant Production of targeted cytotoxic T lymphocytes
Platelet collection:
Collection of platelets from healthy donors. Primarily the role of the blood transfusion service	For patients who, for a multitude of reasons, require a platelet transfusion

Source: Adapted from Choi and Foss ([22]), Schwartz et al. ([101]), Strauss ([106]).

FFP, fresh frozen plasma; LDL, low density lipoprotein.

Contraindications

Contraindications will depend on the reason for undertaking the procedure, that is, donor or therapeutic.

Donors. There are strict processes in place that regulate whether an individual may donate a blood component for therapeutic use. These include FACT‐JACIE's ([40]) International Standards for Cellular Therapy Product Collection, Processing and Administration for stem cell and lymphocyte donors and the regulations that national blood services put forward for platelet and granulocyte donors. Contraindications should be stated in the cell separator facility's standard operating procedure manual. An example of a contraindication for allogeneic donors is a diagnosis of human immunodeficiency virus (HIV).
Patients. It is a medical decision as to whether a patient is fit to proceed with a cell separator procedure for therapeutic reasons. It may be appropriate to undertake a cell separator procedure in a very unwell patient if it is considered to be a life‐saving intervention. For example, some patients with acute myeloid leukaemia present with a high white cell count and are at risk of leucostasis and are therefore referred for white cell depletion. All decisions must be documented in the patient's medical notes.

Principles of care

There has been an increase in the clinical use of cell separators for the treatment of a greater variety of clinical conditions and to collect a greater range of therapeutic products. It is therefore important that careful consideration is given to the likely clinical conditions to be treated, blood products to be collected, the most suitable type of equipment to use and the appropriate training of staff when setting up a cell separator service (Howell et al. [52]).

The decision to use a cell separator for donor or therapeutic purposes is the responsibility of a medical consultant. In view of the known risks and complications associated with the use of cell separators, appropriately trained medical and nursing staff must be in attendance (Howell et al. [52]).