Irradiated Blood

I was a medical student in the mid-1980’s when HIV was identified. At that time I thougt it might be possible to sterilize donated blood by irradiation.

Despite the screening that is applied to blood donations in the USA, it is still possible to transmit HIV and other infectious agents in blood.

Would irradiation of the blood eradicate pathogens that might elude the screening techniques we currently employ? If so, maybe we should consider doing that.

I can imagine reasons why irradiation might not be feasible: 1) It may not kill the pathogens; 2) The energy necessary to disrupt the pathogens might damage and make useless the blood; and 3) Irradiated blood may be as emotionally difficult to accept as irradiated food.

  1. It would turn all the recipients into Spider-Man ("…Is he strong? Listen, Bud…")

It’s already to market

More info here

Main indication is prevention of graft vs host disease in bone marrow transplant patients. My WAG is the level of Rads required for sterilization leads to bad blood.

I read your references. It seems irradiation may decrease the risk of white cell mediated transfusion effects, including GVHD. That makes sense, because the radiation can destroy the leukocyte antigens. But my question was about the acility of radiation to sterilize HIV and other pathogens. Leukocyte depleted blood apparently can reduce the risk of CMV transmission. What about HCV and HIV? Yeah, it can be expensive, but so what? Isn’t the prevention of lethal disease from blood transfussion worth the expense, especially if YOU have to get a transfusion?


I don’t have any cites, but I’ll give you my best WAG.

Point 1: Irradiation does not destroy leukocyte antigens. Proteins and carbohydrates (the antigens in question) are radioresistant. Gamma irradiation irreversibly cross-links DNA strands making replication impossible. GVHD is prevented because lymphocytes in the donor blood cannot multiply and attack the immunodeficient host.

Point 2: Irradiation doesn’t remove leukocytes from blood. Like I said in point 1, it just makes mitosis impossible. However, techniques do exist to remove leukocytes from blood. These would be applicable to situations where you are trying to prevent either:
A. A host immune response to donor leukocyte antigens. In this case the host is immunocompetent, therefore no GVHD worries.
B. Transmission of infectios agents ALWAYS associated with leukocytes in blood and never free-floating in the sera (as is the case with CMV, IIRC, but not HIV)

Point 3: Irradiation could damage viral DNA to the point that the virus couldn’t replicate, but the dose of radiation may be much higher than practical. This point I’m least sure about. However, there is a practical limit as to how high a radiation dose you can deliver to blood. While proteins and cell membranes are radioresistant relative to DNA, the resistance is not absolute, and RBCs and platelets will become dysfunctional at high doses. I think it’s likely that a higher dose will be required to kill viruses. As a general rule, simpler engineering is more robust engineering in biology and viruses are simplicity incarnate. Also, two of the viruses you mention (HIV, HCV) are RNA viruses (they carry RNA as their genetic material). I believe RNA is more radioresistant than DNA.

I have been an RN for 5 1/2 years, mostly taking care of kids with cancer. I’ve always given these kids packed red blood cells that are leukocyte-reduced and irradiated. (not to mention CMV-safe, but i don’t know how they do that part. I guess they just screen it for that).

SuperLorie, the leukocyte reduction makes the blood CMV safe, because CMV is carried in leukocytes, not as free viral particles in the plasma. As an alternative to leukocyte reduction, some places used to use blood from donors who tested CMV-negative by serology; now that universal leukoreduction is becoming the norm, I don’t think that CMV serology testing of blood donors is going to continue much longer.

As to irradiation to prevent viral infections - irradiation shortens the lifespan of the red blood cells (it damages the cell membrane, and causes potassium leakage from the cells; red cells can’t repair the damage because they lack a nucleus and are therefore incapable of performing the necessary protein synthesis). Irradiation at levels high enough to inactivate an RNA virus, which is VERY resistant to radiation damage, would cause massive damage to the red cells - a blood transfusion is of no use to the patient if the blood cells don’t survive long after transfusion. With the PCR-based nucleic acid testing now being phased in as part of the donor screening process, I don’t see that irradiating blood would provide much of a safety improvement anyway.

There are a number of drugs out now that inhibit the replication of HIV in the body. But to actually get rid of all the virus, it seems like you’d have to destroy the kinds of cells it lives in, which wouldn’t be possible without killing the host.

As always, the SD Message Board yields an answer…

Thanks to all. I was mistaken in saying that radiation destroyed leukocyte antigens. It serves to diable their nuclear-directed metabolic processes…

Of course it does not block the leukocytes’ ability to reproduce… differentiated leukocytes do not reproduce themselves, though they can go on living and presenting antigenic substances…

As I noted in my OP, the question is whether or not radiation can sterilize viruses in the blood. Obviously, any viruses can be sterilized by a sufficient dose of radiation. The question is whether that dose will also ruin the blood for transfusion. So far, no one has answered this question.

Actually, Neurodoc , I thought I did answer your question- the level of irradiation needed to inactivate most viruses will ruin the blood for transfusion, because it will cause massive damage to the membranes of the red cells.

Oh, and most of the B-cell leukocytes in your blood CAN reproduce - they’re memory B cells, not plasma cells (the fully differentiated form), and exposure to an antigenic stimulus serves as the trigger for cell division as well as eventual maturation. I don’t remember the biology of T-cells well (and am too lazy to look it up right now), but at least some subsets of T-cells must be able to reproduce, or irradiation wouldn’t work to block the cell-mediated aspects of graft-vs-host disease.