Washed red blood cells are

red blood cells Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek language, Greek ''erythros'' for "red" and ''k ...

which have had most of the

plasma Plasma or plasm may refer to: Science * Plasma (physics), one of the four fundamental states of matter * Plasma (mineral), a green translucent silica mineral * Quark–gluon plasma, a state of matter in quantum chromodynamics Biology * Blood pla ...

platelets Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby ini ...

and white blood cells removed and replaced with saline or another type of preservation solution. 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. These proteins are removed by the process of washing the red blood cells.

Methods of washing red cells

There are multiple methods of washing red cells. These can include automated or manual methods. They can use

centrifugation Centrifugation is a mechanical process which involves the use of the centrifugal force to separate particles from a solution according to their size, shape, density, medium viscosity and rotor speed. The denser components of the mixture migrate ...

or centrifugation-free methods. The red cells can be re-suspended in saline or other types of special preservative solutions for red cells e.g. SAG-M.

Medical Uses

Prevention of recurrence of severe allergic reactions

The most common reason for using washed red blood cells in transfusion medicine is to prevent the recurrence of severe allergic transfusion reactions. The allergen is usually a protein in the plasma that is removed by the process of washing the red blood cells. Various proteins, such as antibodies directed against

IgA Iga may refer to: Arts and entertainment * Ambush at Iga Pass, a 1958 Japanese film * Iga no Kagemaru, Japanese manga series * Iga, a set of characters from the Japanese novel '' The Kouga Ninja Scrolls'' Biology * ''Iga'' (beetle), a gen ...

or haptoglobin in people with IgA and haptoglobin deficiency have been suggested to have a causal relationship with the allergic reaction. Cytokines and chemokines, which accumulate during the storage of blood components, have also been suggested as causative agents. However, the literature is scarce and conflicting as passive infusion of anti-IgA antibodies in to recipients has not been found to cause an allergic reaction.

Reduction in transfusion-related complications

In neonates transfusion has been associated with an increased risk of serious side-effects including: * Necrotising enterocolitis (NEC) *

Intraventricular haemorrhage Intraventricular hemorrhage (IVH), also known as intraventricular bleeding, is a bleeding into the brain's ventricular system, where the cerebrospinal fluid is produced and circulates through towards the subarachnoid space. It can result from p ...

(IVH) * Retinopathy of prematurity (ROP) * Chronic lung disease (CLD) * Death Transfusion-related immune modulation has been thought to be the underlying mechanism. Washing red cells has been thought to be one way of potentially decreasing the risk of theses transfusion-related side-effects. However, in neonates, there is insufficient evidence to say whether washing red cells has any effect.

Storage

Once red blood cells have been washed they can only be kept for up to a day.

References

Blood cells {{treatment-stub Transfusion medicine