What is an apheresis procedure?

What is an Apheresis Procedure

Apheresis is a blood separation procedure in which blood is withdrawn from a patient or donor, passed through a centrifugation system or filtration device that selectively removes or collects specific blood components (such as platelets, plasma, or white blood cells), and then returns the remaining blood components back to the individual. 1

Technical Process

The procedure involves the following key steps:

• Blood is pumped from one vein through a blood-cell separator centrifugation system (apheresis instrument) that physically separates the desired component 1
• The separated component is collected while plasma and other blood cells are returned to the donor's other arm through a second venipuncture 1
• Processing time typically requires 1.5 to 2 hours and involves processing 4,000 to 5,000 mL of the donor's blood 1

Primary Separation Methods

Apheresis utilizes three fundamental physical separation techniques:

• Differential centrifugation - the most common method for separating blood components by density 2
• Membrane filtration - using selective pore sizes to separate components 2
• Adsorption - binding specific proteins or cells from whole blood or pre-separated plasma 2

Clinical Applications

Therapeutic Apheresis

Therapeutic apheresis removes harmful blood components to treat various conditions including hematologic, neurologic, renal, and autoimmune disorders 3, 4. This includes:

• Therapeutic plasma exchange (TPE) - considered first-line therapy for thrombotic thrombocytopenic purpura (TTP) and Guillain-Barré syndrome 4
• Lipoprotein apheresis - removes LDL-cholesterol and lipoprotein(a) in patients with familial hypercholesterolemia, typically treating 1-2 plasma volumes weekly or fortnightly 1

Productive Apheresis (Donation)

Productive apheresis collects blood components for transfusion, most commonly:

• Plateletpheresis - produces single-donor platelets containing 3×10¹¹ platelets (equivalent to 6-9 units from whole blood), though many centers split collections into 2-3 products 1
• Products contain fewer white blood cells (typically <5×10⁶ leukocytes) and are considered leukocyte-reduced 1

Vascular Access Considerations

• Initial access should be via peripheral veins for most patients 1
• Arteriovenous fistula may be needed if peripheral access becomes impossible, particularly relevant for children 1
• Central venous catheters are not recommended except in emergencies or as temporary measures 1

Critical Safety Parameters

For Lipoprotein Apheresis

• Anticoagulant management is essential: warfarin requires dose adjustment or discontinuation several days before procedures using intravenous heparin, while direct oral anticoagulants (apixaban, dabigatran, rivaroxaban) need only be stopped on the day of apheresis 1
• ACE inhibitors should not be used in patients undergoing apheresis based on apolipoprotein B adsorption; substitute with angiotensin-receptor blockers 1
• Monitor for iron-deficiency anemia with routine full blood counts during long-term treatment 1

For Platelet Donation

• Donors must avoid prostaglandin inhibitors (NSAIDs, aspirin) for 8 days before donation to ensure product quality 5

Common Pitfall

Do not confuse apheresis with simple component separation from whole blood. While whole blood can be centrifuged to prepare platelet concentrates using the platelet-rich plasma or buffy coat methods 1, 6, true apheresis is an extracorporeal procedure performed on a living donor or patient with continuous blood flow through specialized equipment 3, 2.