American Board of Internal Medicine (ABIM) Certification Practice Exam

Who is indicated for blood irradiation during transfusion?

1. Patients with iron overload

2. Patients with active infections

3. Patients with severe T-cell immunodeficiency

4. Patients with anemia

The correct answer is: Patients with severe T-cell immunodeficiency

Blood irradiation is indicated for patients with severe T-cell immunodeficiency due to the increased risk of transfusion-associated graft-versus-host disease (TA-GvHD). In patients with T-cell immunodeficiency, the immune system is unable to mount an effective response to the transfused donor T-lymphocytes. This can allow the transfused cells to proliferate and attack the recipient's tissues, leading to a severe and often fatal condition. Irradiation of blood products in this context helps to inactivate T-lymphocytes, thereby significantly reducing the risk of TA-GvHD. This protective measure is particularly crucial for those who have congenital or acquired forms of T-cell dysfunction, where the patient’s immune system cannot control the proliferation of donor T-cells. Other conditions such as iron overload, active infections, and anemia do not warrant irradiation because these are not associated with the same risk of TA-GvHD related to the transfusion of blood products containing viable T-lymphocytes. Thus, while these conditions may require blood transfusions, they do not include the need for irradiation as a preventative measure for this specific complication.