Technical and clinical guidance for all major therapeutic apheresis procedures — mechanism, indication, protocol, replacement fluids, and safety considerations.
All apheresis procedures share a common principle: blood is withdrawn from the patient, passed through a separation device, a target component is removed or modified, and the remaining blood is returned to the patient — usually with a replacement fluid to maintain volume.
Two primary separation technologies are used:
Centrifugal Separation: Blood components are separated by density using centrifugal force. Plasma, platelets, buffy coat (WBCs), and RBCs form distinct layers. Used in the Spectra Optia® system and most modern apheresis platforms.
Membrane Filtration: Plasma passes through hollow-fiber membranes with defined pore sizes, separating components based on molecular weight. Used in double-filtration plasmapheresis (DFPP) and membrane plasma separation.
Spectra Optia (Terumo BCT) — industry reference centrifugal apheresis system
Therapeutic Plasma Exchange (TPE) is the most widely performed apheresis procedure. Whole blood is separated, plasma is removed, and the cellular components are returned to the patient with a replacement fluid. The procedure targets large molecular weight substances: autoantibodies, immune complexes, cryoglobulins, paraproteins, toxins, and inflammatory mediators that would be too large for conventional clearance.
5% Albumin — Most common. Avoids infectious risk and allergic reactions from FFP. Does not replenish coagulation factors.
Fresh Frozen Plasma (FFP) — Required for TTP (replenishes ADAMTS13). Risk of allergic reactions, TRALI, infection.
Combination — Albumin + normal saline combinations used to control cost while maintaining colloid oncotic pressure.
Percent removal of intravascular substance assuming first-order kinetics. Standard practice: 1–1.5 TPV per procedure.
Citrate (ACD-A) is the primary anticoagulant. It chelates ionized calcium, preventing coagulation in the circuit. Monitoring for hypocalcemia is essential. Heparin may be added in select cases. Citrate is metabolized by the liver — caution in hepatic failure.
Citrate-related. Tingling, tetany. Treat with oral/IV calcium supplementation.
Depletion of coagulation factors with albumin replacement. Monitor PT/INR after procedures.
Especially with FFP replacement. Urticaria, anaphylaxis possible. Pre-medicate in high-risk patients.
Large-bore central venous catheter (typically double-lumen) required for most procedures. Options: internal jugular, subclavian, or femoral vein. Arteriovenous fistula or peripheral veins sometimes adequate for scheduled procedures.
RBC exchange removes patient red blood cells and replaces them with donor RBCs. The primary application is sickle cell disease, where exchange rapidly reduces the percentage of hemoglobin S (HbS) while maintaining normal hematocrit — avoiding the iron overload associated with chronic simple transfusions.
Emergent exchange to reduce HbS to <30%, halting stroke progression. Category I, Grade 1C.
Severe cases with O₂ saturation <90% or rapid decline. Improves pulmonary oxygenation. Category II.
Parasitemia >10% with organ involvement in asplenic or immunocompromised patients. Category II.
High parasitemia with cerebral malaria or multi-organ failure. Category III (limited RCT evidence).
Iron Overload Advantage: Unlike simple transfusion, RBC exchange maintains isovolemic conditions and avoids progressive iron accumulation. Essential for patients requiring chronic monthly transfusions for stroke prevention.
| Acute Stroke Target | HbS < 30% |
| Chronic Prevention | HbS < 30% |
| Babesiosis Target | Parasitemia < 5% |
| Target Hematocrit | 28–33% |
ECP separates mononuclear cells (lymphocytes and monocytes) from whole blood, treats them extracorporeally with the photoactive compound 8-methoxypsoralen (8-MOP) and UVA light, and reinfuses the treated cells. The photoinactivated cells trigger an immunomodulatory response rather than a destructive one, making ECP unique among immunotherapies: it modulates, rather than simply suppresses, the immune system.
8-MOP + UVA cross-links malignant/alloreactive T-cell DNA, triggering apoptosis.
Apoptotic cells are phagocytosed by monocytes, which differentiate into tolerogenic DCs.
Tolerogenic DCs shift immune balance toward Treg cells, suppressing pathogenic T-cell clones systemically.
Cutaneous T-Cell Lymphoma (CTCL) — Erythrodermic stage. Only FDA-approved apheresis oncology indication.
| Frequency (initial) | Monthly cycles |
| Days per cycle | 2 consecutive days |
| Min. duration | 6 months |
| Photosensitizer | 8-MOP |
| Light source | UVA (320–400 nm) |
Lipoprotein apheresis selectively removes atherogenic lipoproteins — primarily LDL-C and Lp(a) — from plasma. It is the most effective acute LDL-lowering intervention available, reducing LDL by 50–70% per session. For patients with familial hypercholesterolemia unresponsive to maximal drug therapy, it is life-saving.
Dextran sulfate columns bind apoB-containing lipoproteins. High efficiency; most widely used system in the US.
Processes whole blood directly without plasma separation. More efficient; no replacement fluid required.
Heparin-induced LDL precipitation at low pH. Removes LDL, Lp(a), and fibrinogen. Common in Europe.
Antibody columns bind apoB-100 on LDL. Highly selective; allows plasma regeneration and reinfusion.
Weekly (HoFH) or biweekly (HeFH) sessions. Each session takes 2–3 hours. Lifelong treatment typically required.
Immunoadsorption passes patient plasma through a column containing a highly specific sorbent that binds immunoglobulins or specific antibody targets. Unlike TPE, IA removes antibodies without requiring replacement plasma, enabling processing of 2–3 plasma volumes per session with superior selectivity. The treated plasma is then returned to the patient.
Selectively removes white blood cells from circulation. Primary indication is hyperleukocytosis in acute leukemia (WBC >100,000/µL), where circulating blast cells plug small vessels causing leukostasis — a medical emergency.
Emergency Indication: Leukostasis can cause respiratory failure and stroke. Each procedure reduces WBC by 30–50%. Bridge to chemotherapy — not a substitute.
Selective removal of red blood cells, used therapeutically in polycythemia vera (reduce hematocrit) and hereditary hemochromatosis (reduce iron stores). More efficient than phlebotomy — removes more RBCs per session, requires fewer clinic visits.
Iron Removal (Hemochromatosis): Each erythrocytapheresis session removes ~200–250 mg of iron, compared to ~200–250 mg per phlebotomy — but in fewer total visits due to larger volume removal.
New Reference Standard (2025): AABB Apheresis: Principles and Practice, 4th Edition, Volume 3: Cellular Therapy (2025) is now the authoritative reference for this procedure. See the Guidelines & Reference Library for full details.
Leukapheresis for CAR-T cell manufacturing is a specialized apheresis procedure that collects autologous T-lymphocytes from a patient with hematologic malignancy. These cells are then genetically engineered ex vivo into chimeric antigen receptor T-cells (CAR-T) — a living drug that targets and destroys cancer cells. As of 2024, six FDA-approved CAR-T products exist, all requiring leukapheresis as the starting material.
Unlike traditional therapeutic apheresis (which removes a pathogenic substance), CAR-T leukapheresis collects a therapeutic product. The apheresis nurse's role is to obtain a sufficient yield of viable T-lymphocytes to enable successful manufacturing.
≥1×10&sup9; CD3+ T-cells per collection (product-specific). Verify with manufacturer specifications for each CAR-T product.
10–15 liters total blood volume. Inlet flow rate 50–70 mL/min. Typically 1–2 sessions.
ACD-A (acid citrate dextrose). Standard inlet:ACD ratio 10:1 to 12:1. Adjust for patient tolerance.
Large-bore peripheral IV (preferred), apheresis catheter, or Hickman/PICC. Minimum flow rate 30–40 mL/min required.
Immediate cryopreservation in GMP-grade media. Chain-of-custody documentation required. Shipped to manufacturer within 24–48 hours.
Collect during remission or low disease burden. Avoid G-CSF pre-collection. Avoid steroids >20mg/day prednisone equivalent.
| Parameter | Minimum Threshold | Clinical Significance |
|---|---|---|
| CD3+ T-cell count | ≥1×10&sup9; total | Minimum for manufacturing. Below threshold may require repeat collection. |
| Cell viability | ≥70% | Low viability causes manufacturing failure. Avoid collections during active infection. |
| Monocyte contamination | <20% | Excess monocytes inhibit T-cell expansion during manufacturing. |
| Collection efficiency | ≥50% | Percentage of target cells collected vs. processed. Reflects machine performance and patient factors. |
Patients with lymphopenia from prior chemotherapy may have inadequate T-cell counts. Options: multiple collection sessions, G-CSF/plerixafor mobilization, or lymphodepletion-free bridging strategies.
FDA 21 CFR Part 1271 (HCT/P regulations), AABB Cellular Therapy Standards 8th Ed. (2024), FACT-JACIE accreditation. Chain-of-custody documentation is mandatory from collection through infusion.
DFPP uses a two-step membrane filtration process. The first membrane separates plasma from blood cells. The separated plasma then passes through a second membrane with smaller pores that selectively retains large molecular weight substances (immunoglobulins, lipoproteins, cryoglobulins) while allowing smaller proteins (albumin, clotting factors) to pass back to the patient. This selectivity reduces the need for large volumes of replacement fluid compared to standard TPE.
Hollow-fiber membrane separates plasma from cellular blood components.
Second membrane retains large MW substances; smaller proteins returned to patient.
Removes pathogenic large molecules while preserving albumin and smaller proteins. Less replacement fluid needed.
All procedure protocols, dosing parameters, and technical specifications are derived from the following directly accessed sources. All citations verified February 2026.