What is a potential complication of not irradiating blood products for an immunocompromised patient?

Irradiating blood products is a critical step when transfusing immunocompromised patients to prevent a specific complication known as transfusion-associated graft-versus-host disease (TA-GvHD). This condition occurs when healthy donor lymphocytes present in the transfused blood products begin to proliferate in the recipient’s immunocompromised milieu, leading to the donor's immune cells attacking the recipient's tissues.

Immunocompromised patients, such as those undergoing chemotherapy or with certain immunodeficiencies, have weakened immune systems unable to effectively counteract foreign cells. When these patients receive unirradiated blood products, the risk of TA-GvHD increases significantly because the recipient's body cannot mount a sufficient immune response to eliminate the donor T-lymphocytes that could lead to this adverse reaction.

While iron overload, transfusion-related acute lung injury, and allergic reactions are potential transfusion complications, they are not directly addressed by the irradiation process. Iron overload is primarily a concern with repeated transfusions over time. Transfusion-related acute lung injury stems from a different mechanism related to immune response and is not prevented by irradiation. Lastly, allergic reactions can occur with any transfusion regardless of whether a product has been irradiated or not.