Leukapheresis is a medical procedure that precisely separates white blood cells from a person’s blood. This non-surgical technique is used in various clinical settings. It involves drawing blood, processing it to isolate specific white blood cell components, and then returning the remaining blood to the body. This method allows for targeted intervention.
What Leukapheresis Is
Leukapheresis is a specific type of apheresis, a broader medical technique designed to separate and remove particular components from the blood. Leukapheresis focuses on leukocytes (white blood cells). This procedure serves two main purposes: therapeutic intervention and cell collection.
Therapeutically, it aims to reduce dangerously high white blood cell counts that can occur in certain conditions. For collection, it gathers white blood cells or hematopoietic stem cells for future use, such as transplantation or research. The underlying principle involves separating blood components based on their varying densities.
How Leukapheresis is Performed
The leukapheresis procedure begins with establishing venous access, usually through an intravenous (IV) line placed in each arm. In some cases, a single, larger central line may be used, often placed near the neck or under the collarbone, especially if peripheral veins are not adequate or multiple sessions are anticipated. Blood is continuously drawn from one line and directed into a specialized apheresis machine.
Inside the apheresis machine, the blood undergoes a process called centrifugation, where it is spun at high speeds, causing different blood components—red blood cells, white blood cells, and plasma—to separate into distinct layers based on their density. The white blood cell layer is then selectively collected into a sterile bag. To prevent the blood from clotting as it circulates through the machine, an anticoagulant medication is continuously added.
After separation and collection of white blood cells, the remaining blood components, including red blood cells, plasma, and platelets, are returned to the patient through the second IV line. The entire process is performed in an outpatient setting and typically takes two to four hours.
Common Medical Uses
Leukapheresis is utilized in several important medical contexts, primarily falling into two categories: therapeutic applications and cell collection. Therapeutically, it manages hyperleukocytosis, a condition with extremely high white blood cell counts, often seen in certain types of leukemia. This rapid reduction in white blood cells can prevent serious complications like leukostasis, where the excess cells can clog small blood vessels, potentially affecting organs such as the lungs and brain.
For cell collection, leukapheresis harvests hematopoietic stem cells from the peripheral blood. These stem cells are important for bone marrow transplantation, especially for patients undergoing high-dose chemotherapy for cancers, enabling the reconstitution of healthy blood cell production. Additionally, specific white blood cells, such as T-cells, are collected via leukapheresis for advanced immunotherapies like CAR T-cell therapy, where these cells are genetically modified to target cancer cells before being reinfused into the patient.
Patient Experience and Care
Patients undergoing leukapheresis can expect preparations and sensations. Before starting, patients are advised to stay well-hydrated and wear comfortable clothing. During the procedure, the patient sits or lies comfortably next to the apheresis machine.
While generally not painful, patients may experience sensations. The anticoagulant used can lead to temporary numbness or tingling, particularly around the hands, feet, and mouth, due to a drop in calcium levels. The nurse monitoring the procedure can manage these sensations by administering calcium supplements. Patients may also feel a slight coldness as the processed blood returns to their body.
After the leukapheresis session, patients are encouraged to rest and continue hydrating. The access site should be monitored for bruising or discomfort. While side effects are mild, temporary fatigue is common.