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Alberta Blood Transfusion Information

When Your Child Needs Special Red Blood Cells or Platelets

​​​​​​​During treatment, your child may get blood components (e.g. red blood cells, platelets), which are ordered by a doctor or nurse practitioner (NP).

Many blood components need special processing in the transfusion lab (e.g., irradiation and washing). This takes time, so it may take longer for the blood component to be prepared. If you have questions, talk to your child’s healthcare provider.

Red Blood Cells (RBCs)

One unit of RBC is about 250 to 350 mL. Sometimes, one unit might not be the amount that was ordered by your child’s doctor. If this happens, the doctor or NP will decide if your child needs part of another unit.

What are antigen-negative RBCs?

Antigen-negative RBCs have been tested to show that they don’t have an antigen(s) to which your child may already have made an antibody. There is a lower chance that your child will react to them. Antigen-negative RBCs may be used for regular blood transfusions or exchange transfusions. Finding these special RBCs might take longer.

Antigen-negative RBCs might be given if your child has a RBC antibody or is on a preventative program for hemoglobinopathies (e.g. sickle cell disease, thalassemia) where many of the antigens on the RBCs are matched.

If your child has a RBC antibody and needs a RBC transfusion, the unit needs to be negative for the matching antigen. If on the preventative program, your child will get specially-typed RBCs to prevent him or her from making more antibodies.

What about the age of the RBCs?

Your child will always get the most suitable RBCs.


Platelets are cells the body needs to clot blood. Your child’s doctor or NP will order the amount of platelets your child needs.

What are human leukocyte antigen (HLA)-matched platelets?

HLA-matched platelets are like antigen-negative RBCs. They’re given to decrease the chance of your child making antibodies or they may be given if regular platelets don’t work well because of HLA antibodies.

They can be hard to find depending on what units are available and sometimes units have to be brought in from other cities.

Irradiated Blood Components

What does irradiated mean?

Irradiated means the RBCs or platelets are exposed to radiation (by x-ray or another form of radiation). This is done to prevent a serious disease called transfusion-associated graft versus host disease (TA-GVHD).

What is TA-GVHD?

TA-GVHD is a rare, but serious complication of blood transfusions. It’s caused by white blood cells (lymphocytes) in the transfused donor blood. Sometimes a few of these donor white cells may recognize the patient’s cells are different and start to attack the patient’s own cells. This can cause a serious illness or even death.

People are at risk for TA-GVHD if they have a weak immune system from:

  • taking immunosuppressive treatments ( e.g. for aplastic anemia)
  • taking certain types of medicine (e.g., Fludarabine®)
  • a treatment received during a bone marrow or stem cell transplant
  • receiving a transfusion from a family member (directed donation)

How does irradiation work?

It inactivates the lymphocytes, which prevents them from dividing and causing harm.

Is all blood irradiated?

No. Some hospitals irradiate blood as it’s needed for people at risk for TA-GVHD. It takes about 10 minutes (or longer if other processing is needed). Other hospitals always have a supply of irradiated RBCs and platelets.

Does irradiation damage the blood?

No. When RBCs or platelets are irradiated, it doesn’t affect how they work. The blood doesn’t become radioactive and it won’t harm your child or anyone around them.

Washed Blood Components

What is washed blood?

RBCs and platelets are washed to remove plasma proteins. This may be ordered if your child has had many transfusion reactions or has an IgA deficiency with anti-IgA antibodies.

Washing blood may take up to 2 hours. For safety reasons, the washing process doesn’t start until your child has arrived and is ready to get the transfusion. This is important (especially for platelets) to prevent wasting a blood component that may have been specially prepared for your child.

If you have questions about the blood products your child needs, ask your child’s healthcare team.


Current as of: June 15, 2018

Author: Transfusion Medicine Safety Program, Alberta Health Services