Washed red blood cells are red blood cells that have had most of the plasma, platelets and white blood cells removed and replaced with saline or another type of preservation solution.[1][2] The most common reason for using washed red blood cells in transfusion medicine is to prevent the recurrence of severe allergic transfusion reactions that do not respond to medical treatment. The usual cause of these allergic reactions is proteins in the donor plasma.[3] These proteins are removed by the process of washing the red blood cells.
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