Why are some units of blood irradiated? They tend to be given to immunocomprised patients. What does irradiation actively do to the blood, that makes it safer for these patients?© BrainMass Inc. brainmass.com December 24, 2021, 4:58 pm ad1c9bdddf
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1) Ultraviolet irradiation of blood:
Procedure: A small amount of blood is removed from the patient (this varies according to weight of the patient). The maximum amount of blood that is withdrawn is 1-1/2 cc per pound weight of the patient and it never exceeds 300 cc. An anticoagulant is added to keep it from clotting. The blood is then irradiated with U.V. light through a window in a closed air-tight circuit. The blood is then returned to the patient.
Once is all is needed for most bacterial infections, however, an acute viral infection could require more treatments.
The ultraviolet irradiation stimulates the immune system and various enzyme systems. Through a mechanism which probably involves increased production of lymphokines, (lymphokines are chemical messengers produced by lymphocytes that carry messages between the cells of the immune system) the immune system is activated to "attack" either cancer cells or invading organisms. The exact mechanisms are not known at present.
In 1942, Dr. Virgil K. Hancock and others listed several reactions that were happening:
? Inactivation of toxins.
? Destruction and inhibition of growth of bacteria.
? Increase in the oxygen combining power of the blood and oxygen transportation to organs.
? Activation of steroid hormones.
? Activation of white blood cells.
? Immunostimulation of cellular and humoral immunity
? Stimulation of fibrinolysis
? Decreased viscosity of blood
? Improved microcirculation
? Stimulation of corticosteroid production
? Decreased platelet aggregation
2) Gamma radiation of blood:
Irradiated blood is given to prevent a rare complication of transfusion called transfusion-associated graft-versus- host disease (TA-GvHD).
TA-GvHD is a rare but serious complication of blood transfusion caused by white blood cells (lymphocytes) in the blood transfused. Even a very small number of lymphocytes may recognize the patient receiving the blood as foreign, and cause a severe illness or even death.
Gamma-irradiation of blood prevents lymphocytes dividing and causing harm.
Red cell (blood) and platelet transfusions are not routinely irradiated for all patients, and need to be irradiated on demand.
All granulocyte (white cell) transfusions are routinely irradiated. Plasma products such as fresh frozen plasma, anti-D, albumin, immunoglobulin do not need to be irradiated.© BrainMass Inc. brainmass.com December 24, 2021, 4:58 pm ad1c9bdddf>