American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the primary reason for irradiating blood products?

1. Increase shelf life

2. Prevent transfusion-associated GVHD

3. Reduce bacterial contamination

4. Improve plasma volume

The correct answer is: Prevent transfusion-associated GVHD

The primary reason for irradiating blood products centers around the prevention of transfusion-associated graft-versus-host disease (GVHD). This condition occurs when transfused lymphocytes in the donor blood recognize the recipient's tissues as foreign, leading to an immune response that can result in severe complications and often proves fatal. Irradiation effectively inactivates the donor lymphocytes by damaging their DNA, thus preventing them from proliferating and causing this adverse reaction. This is especially crucial in certain high-risk populations, such as immunocompromised patients, recipients of allogeneic stem cell transplants, or those with certain hematologic malignancies—where the risk of developing transfusion-associated GVHD is particularly elevated. Other options such as increasing shelf life, reducing bacterial contamination, and improving plasma volume, while relevant to blood product management, do not directly address the critical concern that irradiation specifically targets. Therefore, the strategy of irradiating blood products is essential to safeguard vulnerable patients from the risks associated with transfusion-associated GVHD.