- Why there is aneed to irradiate blood?
When blood is given to patients who are immuno-deficient such as cancer patients or patients being operated for organ transplants, blood needs to be irradiated with low dose of radiation to inhibit T- Lymphocyte proliferation. Without this, these Lymphocytes may tend to take over the immune system of the recipient and attack the healthy organs resulting in T-GVHD or Transfusion induced graft versus host disease. This may lead to complications and may be fatal. Even in the case of immuno-sufficient patients, this can take place, if the donor happens to be a close first degree relative due to the lymphocytes getting past the immune system of the recipient undetected like a Trojan horse. Treating of the blood with radiation is considered a sure way to prevent such complications.
- What is the radiation does given to blood in such cases?
A radiation dose of 25 to 35 Gy is considered adequate.
- What type of radiation is preferred ?
Gamma radiation is the preferred choice for this application. This can normally be achieved in a blood Irradiator designed for the purpose.
- Is it safe to irradiate blood using linear accelerators in the radiotherapy departments ?
It is not advisable to do so because such equipment does not provide precise dose delivery of the type needed for the irradiation of blood, where accuracy and uniformity are of utmost importance. Gamma based Blood Irradiators on the other-hand, are tailor made with these features and are capable of delivering uniform dose of the required measure. Giving more dose of radiation than necessary may result in the killing some of the useful component of blood.
- Can irradiation of blood kill HIV viruses ?
Yes, but by giving a much higher dose of radiation will also kill the blood cells and will hence be useless. Hence this method cannot be resorted to for such a purpose. The same argument holds good for other bacteria and viruses also.
- Does irradiation induce radioactivity in blood ?
No. The radiation energy that is used in this case is not capable of inducing radioactivity.