Leukocytes Indications and Dosage

Leukocytes are probably the least frequent blood product requested of a transfusion service. There are a variety of leukocyte products, some of which are mostly of research interest. For example, there has been interest in the use of interleukin-2 stimulated lymphokine activated killer cells (IL2-LAK) and in the use of ex vivo monocytes stimulated with gamma interferon [EVLA] treatment in the adoptive immunotherapy of cancer. Both of these are largely experimental and have not come into routine use at this time. This Chapter will focus exclusively on granulo-cyte concentrates.

The types of granulocyte concentrates available are shown in Table 30.1. As discussed with platelet products (Chapter 28), granulocyte concentrates can be produced from either a whole blood donation, in which case it is known as a buffy coat, or by the use of apheresis devices. Apheresis granulocytes are essential for adult recipients and may be the preferred product for neonates, but timely availability can limit their use for this latter population.

The buffy coat product has a low volume, similar to random donor platelets but, unlike platelets, contains large numbers of red cells and thus requires ABO compatibility. Approximately 65-75% of the leukocytes present in the whole blood donation are concentrated in the buffy coat and the content, therefore, of granulocytes is approximately 1 x 109. The apheresis granulocyte concentrate has a much larger volume. It will contain many red blood cells and have a hematocrit of approximately 20, therefore, also requiring ABO compatibility. The granulocyte content in the standard apheresis granulocyte concentrate is generally between 1-3 x 1010 i.e., approximately 10 times as many granulocytes as a buffy coat product. Recently, there has been interest in stimulating normal healthy donors with GCSF prior to white cell collection. The white cell count of the apheresis donors increases to 20 x 109/L (20,000 mm3) or greater and granulocyte content of the granulocyte concentrate collected is correspondingly greater, containing up to 10 x 1010 granulocytes. These products are neither licensed nor generally available as yet.

The indications for the use of these concentrates are shown in Table 30.2. For practical purposes, buffy coats are used almost exclusively in the treatment of neonatal sepsis with neutropenia or qualitative granulocyte disorders. In adult practice, apheresis granulocytes are used in infected neutropenic adults. Currently available granulocyte concentrates are not known to be useful in the prophylaxis of neutropenic infections and only patients with active infections under conditions as suggested in Table 30.2, may be candidates for granulocyte concentrates. Most oncologists treating patients with neutropenic fever have abandoned the use of granulocyte concentrates as clinical results have been disappointing.

Table 30.1. Granulocytes concentrates

1. Type of Products:

a) Buffy coat from whole blood donations i) Buffy coat: volume 30-50 ml

b) Apheresis Granulocytes:

• Hct of approximately 20

• Standard product: 1-3 x 1010 granulocytes GCSF stimulated donors: 4-10 x 1010 granulocytes

2. Granulocytes should be transfused as soon as possible after collection and never transfused using a leukoreduction filter. This may preclude completion of the usual tests for viral markers and justification of the clinical need may be required in writing from the prescribing physician.

3. Commonly, granulocytes are irradiated (Chapter 37) since the recipient is frequently immunocompromised: Some centers routinely irradiate all granulocyte concentrates.

4. These products may need to be manufactured from donations which are cytomega-lovirus seronegative, as a leukoreduction filter cannot be used.

5. Transfuse over two hours; reactions are not uncommon and managed by slowing infusion, steroids, acetaminophen or antihistamine as appropriate. Amphotericin B infusion should not be concurrent with granulocyte transfusions.

Table 30.2. Granulocytes: indication and dosage

1. a) Buffy coat: Neonatal sepsis with neutropenia b) Apheresis Granulocytes:

Suspected or proven gram negative sepsis or fungal infection i) With evidence of persisting infection, e.g., fever > 38.5°C x 48 h despite treatment with appropriate multiple antibiotics using an appropriate dosage regimen.

and ii) Neutrophil count < 0.5 x 109/L, without expectation of white cell recovery for 5 days and iii) Adult with an expected survival of > 2 months

2. Dosage and Scheduling:

a) Buffy coat—1 product

It is possible, however, that granulocyte concentrates will prove of greater benefit in the future if data on collections from GCSF stimulated donors show better clinical responses and assuming that GCSF does not cause significant side effects in the healthy donor. Early experience with these higher potency granulocyte products is that recipients show increases in white cell count posttransfusion (which is not observed with the standard granulocyte concentrates) and resolution of fever. Thus, the standard granulocyte concentrates appear limited by a lack of potency, and therapeutic efficacy may only be achieved in most recipients when this is improved.

With regard to scheduling of these products, buffy coats are usually transfused as a single dose, but multiple doses may be administered on a daily basis. For apheresis products, however, it is common practice to transfuse a product on a daily basis for a total of 3-5 days. Although many patients receiving granulocytes are also receiving leukocyte-reduced blood products, leukoreduction filters (Chapter 36) must never be used for granulocytes. On account of this, granulocytes may need to be from CMV seronegative donors, if such an indication exists in the recipient.

Most transfusion services or blood centers will ensure that the product is irradiated either prior to shipment or transfusion (Chapter 37). The absolute need for irradiation of all granulocytes is not established, but if doubt exists, it is best to irradiate as many recipients of these products are immunocompromised.

Granulocytes are stored at 20-24°C without agitation and the shelf life of granu-locyte concentrates is 24 hours. It is recommended, however, that they be transfused promptly and within 8 hours of collection, if possible. This will require the Blood Center to ship these products often without completion of viral disease testing and therefore documentation of the urgent clinical need will be needed. Granulocytes are transfused slowly (2 hours) and as emphasized, leukoreduction filters must never be used; the standard nylon meshwork filter (Chapter 8) is used in the administration set. Reactions to granulocytes are common, but most can be managed with acetaminophen, steroids or antihistamines. Severe reactions causing pulmonary edema and acute dyspnea are most feared and will need careful monitoring and intervention with ventilation if these occur. Some of these recipients may be receiving amphotericin B as an antifungal agent and it is recommended practice that the granulocyte transfusion and the amphotericin B infusion be separated by several hours in order to prevent pulmonary reactions.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

Get My Free Ebook


Responses

  • Medardo
    Are leucoyctes transfused with transfusions?
    3 months ago

Post a comment