Note: This is an updated version of a previous post.
Washing RBCs removes plasma and reduces the leukocyte count only by 1 log. For leukodepletion, we must rely on filtration to reduce the WBCs to less than 1 x 106 per unit according to CE rules. Red cells or platelets in additive solution contain only minimal plasma (about 35 ml). There are few definite indications for washing RBCs and it should be rarely necessary.
Washing RBCs should only be done in the following circumstances:
- Deglycerolization of frozen RBCs.
- Severe allergic or anaphylactic reactions to plasma proteins
- IgA deficiency with anti-IgA
- Paroxysmal nocturnal hemoglobinuria PNH—relative indication (often these patients receive RBCs before the diagnosis of PNH is confirmed)
- Transfusing a previously irradiated RBC unit for pediatric use if more than 24 hours has passed since it was irradiated.
- Any other time when so designated by a transfusion medicine consultant.
- If anyone requests washed RBCs and it does not fit into one of the above categories, contact the transfusion medicine consultant.
- Washed RBCs are NO substitute for leukodepleting RBCs by filtration NOR can they be used in place of irradiation for prophylaxis against transfusion-associated-graft-versus-host disease TAGVHD. Using the Reveos automated component processing system, all components are leukodepleted—RBCs are released in SAGM.
Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA