White blood cell transfusions, technically termed granulocyte transfusions, are possible but not routine. This highly specialized therapy delivers a specific category of white blood cells. Unlike common transfusions of red blood cells or platelets, this process is complex and rare. Its rarity stems from severe logistical difficulties in collection and storage. The procedure offers a temporary, targeted boost when the body’s natural defenses have been severely compromised.
Defining Granulocyte Transfusions
Granulocytes are white blood cells characterized by internal granules. This group includes neutrophils, eosinophils, and basophils, but the transfusion product focuses on providing functional neutrophils. Neutrophils are the body’s most abundant first responders, primarily engulfing and destroying invading bacteria and fungi. A granulocyte transfusion is a supportive therapy designed to temporarily augment the immune response. The goal is to provide immediate, active infection-fighting cells to bridge the time until the patient’s bone marrow recovers. These transfused cells have a very short lifespan, surviving only about six to eight hours, often necessitating immediate and repeated administration.
Specific Patient Conditions Requiring Transfusion
Granulocyte transfusions are reserved for patients experiencing severe immune system compromise. The most common criterion is severe neutropenia, defined as an absolute neutrophil count (ANC) below 500 cells per microliter of blood. This low count frequently occurs following intensive chemotherapy or a hematopoietic stem cell transplant, when the bone marrow is temporarily unable to produce sufficient white blood cells. The patient must also have a bacterial or fungal infection that has not responded to standard antimicrobial medications for 24 to 48 hours.
This situation describes a refractory infection, where aggressive regimens have failed to control the pathogen. This therapy may also be considered for individuals with congenital disorders, such as chronic granulomatous disease (CGD), where neutrophils are present but functionally defective. The patient must be expected to eventually recover their own bone marrow function, allowing the therapy to provide immediate immune support until the body resumes its natural defense capabilities.
The Specialized Donation and Storage Process
The logistical demands of obtaining granulocytes are significant. The cells are collected through leukapheresis, where blood is drawn from the donor, passed through a machine to separate the white blood cells, and the remaining components are returned.
To ensure a sufficient number of cells are collected, the donor is pre-treated with medications, typically a corticosteroid like dexamethasone and Granulocyte Colony-Stimulating Factor (G-CSF). G-CSF mobilizes neutrophils from the bone marrow into the peripheral bloodstream, significantly increasing the potential yield to between 4 to 8 x 10¹⁰ granulocytes per unit. This pre-treatment makes the donation a multi-day process requiring careful coordination.
Once collected, the product faces a severe time constraint. Granulocytes have a functional life of less than 24 hours, meaning they must be transfused almost immediately. The product is stored at room temperature and is not agitated, unlike platelets. Because the final product contains red blood cells, the donor must be matched to the recipient for ABO and Rh blood types. For patients who have developed antibodies to human leukocyte antigens (HLA), a complex HLA compatibility match is required to prevent the transfused cells from being destroyed.
Potential Complications for Recipients
Receiving a granulocyte transfusion carries significant risks for the recipient. The most frequent adverse events include fever, chills, and allergic symptoms. These reactions are often managed by giving the patient preventative medications before the transfusion begins.
A more severe, though less common, complication is Transfusion-Related Acute Lung Injury (TRALI), a serious condition that causes acute respiratory distress shortly after the infusion. Because the product contains lymphocytes, it must be irradiated to prevent a rare but fatal Transfusion-Associated Graft-Versus-Host Disease (TA-GVHD). The short shelf life means the product is often issued before complete infectious disease testing is finalized, necessitating stringent screening of repeat donors to minimize pathogen transmission risk. The introduction of foreign white blood cells can also lead to the development of antibodies against human leukocyte antigens (HLA alloimmunization, which may cause future platelet transfusions to become ineffective.