Question

10-day-old infant was admitted for a transfusion following a hospital stay with significant blood drawing. The hematologist ordered 100 cc of irradiated packed red cells. The hospital must request irradiated cells from a local trauma center. This request is made on a Saturday morning and you are reluctant to make this request as it requires paid couriers and your administration is concerned about expenses. Is it necessary to provide irradiated blood? If so, why? Is packed red cells an acceptable alternative?

Answer 1

Answer :

In the question, the infant (presumably term infant) has been admitted to correct anemia, that resulted from frequent blood sampling.

Packed cells vs Whole blood

Packed cells are definitely advantageous than whole blood in this case because of two reasons :

Packed cells serve the purpose of correcting anemia, without causing wastage of other blood components.

Packed RBC transfusion has lower risk of causing circulatory overload than whole blood, especially in infants.

Irradiated vs Non irradiated RBCs

Irradiated RBCs are particularly indicated for premature inffants, and patients with cellular immunity defects.

In the given case, irradiated RBCs are preferable, but not mandatory; presuming that the baby is not premature.

EXPLANATION

IRRADIATED BLOOD PRODUCTS

Purpose of Irradiation

• Prevention of TA-GVHD (Transfusion Associated Graft vs. Host Disease).
• Causes DNA crosslinks, thereby preventing lymphocyte replication without significantly damaging red blood cell, platelet or granulocyte function.

Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare and acute delayed transfusion reaction which occurs after the transfusion of blood components;

The basic mechanism behind the occurrence of TA-GVHD is the transfer of T lymphocytes from the donor blood that damage and initiates a response in the tissues of the recipient.

After recognizing host tissues as foreign, transfused T lymphocytes release cytokines such as interleukin-1 (IL-1) and tumor necrosis factor (TNF) .

These cytokines activate inflammatory cells, including natural killer (NK) cells, macrophages, and other T lymphocytes, resulting in the destruction of the tissues of host; thereby causing TA-GVHD.

There is another mechanism where TA-GVHD occurs by virtue of donor-recipient HLA incompatibility.

Indications for irradiated blood products

• Immune suppressed patients with deficient cellular immunity.
• Congenital T-cell deficiencies syndromes (DiGeorge’s, SCID, Wiskott-Aldrich)
• Stem cell/bone marrow transplantation - Note : Because many patients with diagnosis of hematological malignancies go on to receive stem cell transplants, they are also given irradiated products.
• Intrauterine or exchange transfusions for premature neonate transfusions. Treatment with purine analogues, like fludarabine.
• Premature infants (weight <1.2 kg).

Contraindications for irradiated blood products

a) Irradiation is contraindicated for hematopoietic progenitor cell and donor lymphocyte infusions , as it will inhibit their ability to engraft and achieve their desired effects.

Drawbacks

a) The life span of irradiated RBCs is shortened ( to 28 days after irradiation).

b) Potassium leakage from the RBCs into the extracellular fluid increases after irradiation.This could be detrimental for large volume infusions, or when infused close to the heart via central venous catheters particularly in infants and small children. Washing of stored irradiated RBC units may be indicated in these patients.