Blood Transfusion Adverse Effects Practice Test 2026 - Complete Exam Prep

Transfusion-associated graft-versus-host disease happens when donor T lymphocytes in a blood product engraft in the recipient and attack the person's tissues. The most reliable way to prevent this is to inactivate those donor T cells before transfusion. Irradiating blood components delivers gamma rays that damage the DNA of lymphocytes, so they can’t proliferate or mount an immune attack. This prevents TA-GVHD even when the donor cells are able to engraft, which is why irradiation is routinely used for at-risk patients, such as those with impaired immunity, neonates and intrauterine or very young transfusion scenarios, and recipients of directed donations from relatives or stem cell transplant patients.

Leukoreduction reduces the number of donor white cells and helps with febrile reactions and CMV transmission, but it does not reliably prevent TA-GVHD because even a small number of viable donor T cells can cause the condition. Warming the blood or prestorage pooling doesn’t address the donor T cells’ capacity to cause GVHD, so they aren’t effective prevention methods in this context.