Irradiated blood components are used to prevent:

Irradiated blood components are specifically used to prevent graft-versus-host disease (GVHD) in patients who are immunocompromised. GVHD occurs when immunocompetent donor lymphocytes engraft and proliferate in the immunocompromised recipient, leading to severe and often fatal complications. This risk is particularly significant in patients undergoing treatments such as stem cell transplants, those with certain leukemias, or patients receiving high-dose immunosuppressive therapies.

Irradiation effectively inactivates the T lymphocytes in the transfused blood components, thereby preventing them from mounting an immune response against the recipient's tissues. This method is crucial in protecting vulnerable patients from GVHD, making irradiated blood products a standard practice in such clinical settings.

Other options may involve various aspects of blood transfusions, but they do not directly relate to the specific mechanism of action of irradiated blood components in preventing GVHD.