Though it has been the standard practice to use cesium-137 irradiators for transfusions, the FDA has approved using x-ray technology instead. This means you can now prevent TA-GvHD without the use of the radioactive isotope.
Both the Nuclear Threat Initiative and the National Nuclear Security Administration are working towards having all cesium blood irradiators out of use in the U.S. by the year 2027.
By choosing not to replace their old machines with the new, institutions are opening themselves up to a great amount of liability. The x-ray technology of the new machines actually protects the institutions from any losses that come with acts of terrorism.
To continue to use cesium-137 devices, those in charge of operations have more responsibility in making sure they are following regulations in using and storing the devices. All senior management and users of the machines must be informed of the risks, security threats, and be given information about alternative options.
Many top executives of institutions do not realize that they even have irradiators and insurers don’t offer policies that would protect them in the case of a bomb being used from the irradiator materials.
TA-GvHD
TA-GvHD, transfusion-associated graft-versus-host disease, is a fatal complication of blood transfusions, though it is extremely rare.
The lymphocytes from the donor blood or blood component attacks the recipient tissues. This particularly affects the skin, bone marrow, and gastrointestinal tract.
One of the reasons it is so fatal is due to the fact that the symptoms are not easily caught in the early stages because they are very nonspecific. These symptoms often are believed to be part of the recipient’s underlying condition.
Once the invading lymphocytes attack the bone marrow, bone marrow aplasia happens which leads to the main cause of death, pancytopenia.
Patients that are most at risk for experiencing this severe complication include:
- Recipients of fetal and neonatal intrauterine transfusions
- Immunocompromised patients
- Those that receive cellular components from a blood relative
- Patients that are known to receive components of an HLA compatible donor
- Those who undergo marrow or peripheral progenitor cell transplantation
Unfortunately, there are no effective treatments for this reaction. With this being said, prevention is the only defense for the fatal complication.
This preventative action is where irradiation comes in. Typically any blood or component would be processed through an irradiation device. Initially, these were gamma irradiation machines, but now there is a safe option in x-ray irradiation.
What irradiation does is prevent the proliferation of any viable T lymphocytes that could possibly lead to the transfusion recipient to develop TA-GvHD.
There are only two types of irradiation machines that are FDA approved, the more traditional gamma-ray devices, and the more innovative and safer x-ray devices.
X-ray Irradiation
The problem with gamma-ray irradiation is that it utilizes cesium-137 which is a radioactive isotope that carries significant risks. Exposure to the isotope can cause burns when exposed externally.
In general, exposure can also cause acute radiation sickness and/or death. It can also increase the risk of cancer.
Internal exposure will actually allow the isotope to be distributed throughout a person’s soft tissues including muscle tissue. This exposure leads to exposure of beta particles, again, increasing the risk of cancer.
Studies have proven that x-ray irradiation is equally effective at inactivating T-lymphocytes as gamma irradiation.
The biggest difference is that the x-rays can be attenuated making dose distributions variant. Dosimetry of x-ray irradiation needs to be checked precisely.
The x-ray devices also provide the radiation at a more varying range of energy than the cesium machines which offer a single energy emission level.
There is currently work in progress in the way of the Cesium Irradiator Replacement Project and Off-Site Source Recovery Program to completely eliminate the use of cesium-137 reliant machines in the United States.
X-ray irradiation is the FDA recognized method for prevention of transfusion-associated graft-versus-host disease, TA-GvHD.
RADGIL 2
The RADGIL 2 comes from the Gilardoni company and is an x-ray irradiator. This machine is specifically designed to deactivate the donor Lymphocytes-T during the transfusion to prevent TA-GvHD.
Gilardoni already has these machines working in Italy, Africa, the Middle East, and Europe and is starting up in the U.S. The company itself is a top brand in manufacturing the best in medical institution machines and tools.
The x-ray technology is a modern and safer alternative to irradiation of blood components using radioactive isotopes such as cesium-137.
The dosing of this machine can be adjusted which makes it usable for research of cells and tissues, bone marrow ablation, sterile insect technique, and other general research purposes.
The features of the RADGIL 2 include faster irradiation times due to high dose rates, uniform distribution through a rotating canister, UL for electrical and radiation safety, and it is cleared by the FDA for irradiation of blood components.
This machine offers a much safer and more economical alternative to its cesium using counterpart.
RADGIL 2 can treat up to 6 bags of 300ml of blood components in the emo configuration but outside of that, it is adjustable to high or low for optimal irradiation coverage.
The machine can deliver 7Gy per minute on 1800ml and a 30 Gray dose only takes 5 minutes.
Conclusion
Until now, the risk of using a radioactive isotope for irradiating blood components was much less than running the risk of developing TA-GvHD from a transfusion. However, there has been work that has produced a safer alternative.
This alternative allows blood and any components of blood to be irradiated with the use of x-ray technologies.
Using this technology not only reduces the risk of patients or workers being exposed to the isotope but also that the gamma-ray devices are less likely to fall into the hands of people that would misuse the isotope.
There is a great risk of the gamma-ray devices being stolen and used as bombs in terrorist attacks.
Not only does this risk the safety of the general public, but it also risks the financial stability of the medical institutes the devices belong to as the majority of insurers do not offer policies to cover such circumstances.
