Blood and blood components often are irradiated prior to transfusion to prevent the proliferation of certain types of T lymphocytes that can inhibit the immune response and cause graft-versus-host disease. This procedure is necessary for transfusion recipients at risk for GVHD, including fetuses receiving intrauterine transfusions, select immunocompetent or immunocompromised recipients, patients undergoing hematopoietic transplantation, individuals receiving platelets selected for HLA or platelet compatibility, and individuals receiving units from blood relatives.
Irradiation is performed using cesium-137 or cobalt-60 in self-contained blood irradiators or hospital radiation therapy machines. The amount of cesium or cobalt in these machines exceeds the minimum levels for radioactive units as defined by the Nuclear Regulatory Commission — an independent government agency that regulates the use of nuclear materials through licensing, inspection and enforcement of its requirements. Therefore, blood establishments with irradiators must be licensed by the commission. States and cities may have additional inspection and licensure requirements for these establishments.
On behalf of the transfusion medicine community, AABB works directly with the Food and Drug Administration to ensure appropriate irradiation guidance and regulations for blood products. AABB also works with the NRC to communicate the needs and concerns of the blood community regarding security and compliance with radioactive material requirements.
The Radiological Devices Panel of the Medical Device Advisory Committee met to advise FDA on the device classification of blood irradiators. In its public statement, AABB recommended that no measures be added for use of blood irradiators and that the devices be classified as class I or II. After discussions, the panel advised FDA that class II with general and special controls would be appropriate.