Modifications

Red cells can be modified during the manufacturing process to help meet the clinical needs of certain patients. Red cells can be frozen, washed and collected from IgA deficient blood donors.

Frozen red cells

Red cells can be frozen for up to 10 years or sometimes longer if there is a particular need for specific units of rare red cells. Glycerol is added to red cells as a cryoprotective agent and then frozen at or below -65°C.

Prior to transfusion, the glycerol must be removed from the thawed component by washing the red cells with sodium chloride. After washing, the red cells are resuspended in additive solution and must be transfused within 24 hours. There is a significant loss of red cells during the freezing and thawing process, and this process takes several hours to complete. 
  

When should I use this modification?

For patients with rare red cell phenotypes or who have multiple red cell antibodies, or for autologous collections where liquid-preserved blood can’t meet the patient’s needs.

Washed components

Red cells are washed to remove the majority of unwanted plasma proteins, antibodies and electrolytes. 

Some red cells are lost during this process.  

When should I use this modification? 

The following groups of patients should receive washed components: 

  • patients with reactions to transfused plasma proteins (e.g. patients who have IgA deficiency due to IgA antibodies) 
  • multi-transfused patients with severe recurrent febrile, urticarial and possible anaphylactic reactions 
  • patients with paroxysmal nocturnal haemoglobinuria who experience reactions despite receiving group-specific leucodepleted fresh red cells 
  • patients with T-activation when units from donors with low anti-T titres are not available, however this is rare, and 
  • patients with severe autoimmune haemolytic anaemia where excess complement may worsen red cell destruction. 

IgA-deficient components

Red cells can be washed to provide an lgA-deficient product.

lgA-deficient platelet and plasma components are sourced from lgA-deficient donors with an lgA level <0.01 g/L.

When should I use this modification?

IgA-deficient components are indicated for severely IgA-deficient patients with known IgA antibodies who experience recurrent severe allergic or anaphylactic reactions.

More about modifications

Cytomegalovirus (CMV) seronegative components

A limited number of donors, including new donors and donors previously identified as cytomegalovirus (CMV) negative are tested for the presence of CMV antibodies.

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Phenotyped components

Phenotyping can be performed for red cells and platelets. They may be used for the prevention or management of alloimmunisation to human leucocyte or platelet antigens.

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Irradiated components

Irradiated blood components are used to prevent transfusion-associated graft-versus-host disease (TA-GVHD).

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Further information

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