Each year almost 700.000 blood transfusions are administered to patients in The Netherlands, which contain dangerous amounts of blood donor immune cells (lymphocytes) (Annual report 2014, Sanquin) These are often patients involved in a serious accident, requiring surgery or cancer patients with low blood counts.
The lymphocytes of the healthy blood donors recognize the tissues/cells of the recipient as ‘foreign’ and vice versa the lymphocytes of the recipient are recognizing the donor lymphocytes as ‘foreign’ or not self. Consequently, the donor and recipient lymphocytes start to fight each other.
A sick patient, who receives numerous blood transfusions, can loose the battle if the donor lymphocytes defeat the lymphocytes of the recipient. This sometimes causes a rapidly lethal form of Graft-versus-Host disease (GvHD). Symptoms: fever, skin rejection, diarrhea, liver failure and low blood counts. Milder forms of Transfusion associated GvHD can be lethal or cause prolonged stays in Intensive Care units to solve the multi-organ system damage and/or prolonged immunodeficiency caused by GvHD.
Radiating a blood transfusion with a high radiation dose (25Gy) prior to administration will prevent all forms of TaGvHD. The lymphocytes in the blood bag are killed by radiation; the donor red cells and platelets are not affected by the radiation. Radiating blood bags is safe, has been approved for use for more than 4O years, but is underused in The Netherlands.
P2T proposes to radiate almost all blood transfusions with 25Gy prior to administration. An additional advantage of transfusion blood irradiation is the sterilization of DNA and RNA virus particles carried by the donor, for example Hepatitis, B, C, D, and HIV, Cytomegaly virus, because radiation causes double and single strand breaks in viral RNA and DNA.
P2T has improved the logistics of blood irradiation by constructing a new blood bag container (patent pending), in which 20 blood bags can be irradiated to a homogeneous 25Gy dose by a 6MV linear accelerator within 30 minutes. The allowable storage time for irradiated blood bags is 4 days.
The only groups of patients, who need to be transfused by un-irradiated blood, are patients on a waiting list for an allogeneic kidney, liver or heart transplant.
The transfusion of irradiated blood will prevent annually at least one hundred deaths and a thousand to ten thousand admissions to intensive care units.
TaGvHD occurs more often in children than in adults. It is more common in men than in women. The diagram – taken from ‘Radiation Chimeras’ 1967, Academic Press – by D.W. van Bekkum and M.J de Vries.