As described in the Technical Manual (21st Edition) and Circular of Information (December 2021), cellular blood components are irradiated prior to transfusion to prevent the proliferation of viable T lymphocytes which are the immediate cause of Transfusion Associated-Graft Versus Host Disease (TA-GVHD). TA-GVHD, a rare complication (fewer than one per million transfusions result in TA-GVHD), has a fatality rate greater than 90%. Patients at particular risk of TA-GVHD include:
The Circular of Information for Human Blood and Blood Components has detailed information on indications for use, safety and hazards.
The AABB Technical Manual discusses TA-GVHD, blood irradiation, and radiation safety.
The following devices are FDA-approved/cleared “for use in the irradiation of blood and blood products (packaged in transfusion bags) to inactivate T-lymphocytes for the prevention of Graft Versus Host Disease...”:
Refer to the FDA website for more information.
INCREASED SECURITY MEASURES:
The US NRC requires increased security measures to reduce the risk of unauthorized use of radioactive materials for gamma irradiators.
The US Office of Radiological Security (ORS) offers federally funded security enhancements for radioisotope-based blood irradiators that are above and beyond the NRC’s Part 37 requirements – see Additional Resources section.
ELIMINATION OF DEVICES USING CS-137
The goal of the Cesium Irradiator Replacement Project and the Off-Site Source Recovery Program is to eliminate the use of blood irradiation devices that rely on cesium chloride (Cs-137) in the United States through voluntary replacement. Section 3141 of the John S. McCain National Defense Authorization Act for Fiscal Year 2019 includes a provision that requires the Administrator for Nuclear Security to ensure that goal is met by December 31, 2027.
ADDITIONAL GOVERNMENT RESOURCES: NNSA, ORS, NUCLEAR THREAT INITIATIVE
ORS – Information on X-ray vs. Radioisotopic Irradiator Considerations
ORS - Cesium Irradiator Replacement Project Learn More About Permanent Risk Reduction and Incentives Offered by the Office of Radiological Security
ORS – Frequently Asked Questions
ORS - Viable Alternative Technologies for Permanent Risk Reduction
ORS - Cesium Irradiator Replacement Program (video)
NTI - Preventing a Dirty Bomb: Resources for Hospitals and Research Centers
NTI - NTI Partners with the State of California on Radiological “Dirty Bomb” Risk Reduction
NTI - Nuclear Threat Initiative Partners with New York City on First-of-its-Kind, Citywide Approach to Remove Radiological “Dirty Bomb” Risks
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.