Irradiation and beyond: Mitigating TA-GVHD in transfusion.

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare but often fatal complication of allogeneic transfusion, caused by the activation and expansion of donor T lymphocytes in susceptible recipients. Prevention focuses on reducing these immune cells through leukoreduction and irradiation. While leukoreduction of blood components decreases white blood cell content and improves overall transfusion safety, it does not fully prevent TA-GVHD, as viable T cells may persist. Irradiation using gamma or X-ray methods remain the most effective strategy, inactivating donor T cells by inducing DNA damage and suppressing proliferation. However, it also compromises red blood cell quality by increasing hemolysis, oxidative injury, membrane damage, extracellular potassium, and reducing storage duration. As an alternative, hypothermic storage of leukoreduced red blood cells is gaining attention. Evidence suggests that extending storage beyond 21 days significantly reduces T cell viability and proliferation without compromising red blood cell integrity. Further research is needed to directly compare the efficacy of hypothermic storage to irradiation.