While you might think that a blood transfusion may save your life in a serious situation, there may be a few added drawbacks to the life-saving procedure. One of these drawbacks, in fact, can be the development of new allergic reactions to things that never bothered you before. In a new study published this week Canadian doctors revealed that a young 8-year-old boy went into anaphylactic shock from uncommon allergens, merely days after a platelet transfusion. And they fear now that it had everything to do with the platelet donor, whose severe food allergies had not been taken into account before the transfusion took place.
The Canadian patient received several blood transfusions earlier this year as part of his treatment for his life-threatening brain tumor. But less than two weeks after the procedure the boy suddenly came down with allergic reactions to foods that he had never had problems with before. The first, a piece of salmon, caused swelling and for the boy's heart rate to fall, then four days later a peanut butter cup induced a bout of vomiting.
"Right away, we wondered what was happening that was different" the boy's allergist and lead author of the study, Dr. Julia Upton says. "Why would he all of the sudden react to a food that he clearly has eaten for years?"
Consulting with the boy's oncologists Upton revealed that the transfusion may have been cause of the allergic reactions. She had heard of "passive transfer" of allergies through blood transfusions before, and when it was revealed that the donor had given the boy a lot of his plasma Upton revealed that he had given him a lot of his food allergies as well.
"It just so happened that one of blood products that the child received contained a lot of plasma from that donor" Upton says. "The plasma is where the antibodies are."
Typically these antibodies aid patients in the boy's position to fight off harmful bacteria and viruses that their weakened bodies may not be able to protect itself from under normal conditions. But in a case of someone with allergies, these antibodies cause a sort of auto-immunological pathway, wherein when activated by a potential allergen these antibodies create a less than pleasant reaction. Ranging from swelling and hives, all the way to death, the symptoms of these allergic reactions can be life-threatening, but Upton and her colleagues are confident that the boy's case is not only manageable but also exceedingly rare.
As most blood transfusions come from pooled sources of multiple donors, allergists say that the case likely only became an issue if the primary donor's plasma was in abnormally high concentrations.
"There had to be a high enough concentration from a single donor [to produce such a reaction with antibodies found within the boy]" allergist with Vanderbilt University Medical Center, not involved with the study, Dr. Stacy Dorris says. "I think it's exceedingly rare."
