Boy develops food allergies after blood transfusion

An eight-year-old Canadian boy who previously had no food allergies recently became allergic to fish and nuts after receiving a blood transfusion, according to a new report.

The transfusion was part of his treatment for medulloblastoma, a type of brain cancer, and caused him to have a severe allergic reaction called anaphylaxis within 10 minutes of eating salmon.

Published in the Canadian Medical Association Journal, the child’s doctors suspected that the blood transfusion had triggered the reaction, and they treated him with a drug containing antihistamines, which treated his symptoms. The doctors advised him to avoid fish and to carry an epinephrine injector (EpiPen) in case he had another reaction.

However, just days later, the boy was back in the hospital after eating a chocolate peanut butter cup and experiencing a similar reaction to the one he had after eating the salmon. Doctors ran blood tests and a skin prick test suggested that he was not only allergic salmon but also to peanuts as well.

“It’s very rare to have an allergic reaction to a previously tolerated food,” the report’s senior author, Dr. Julia Upton, a specialist in clinical immunology and allergy at the Hospital for Sick Children in Toronto, said in an article. “The overall idea is that he wasn’t allergic to these foods, but in the blood transfusion, he received the protein that triggers an allergic reaction to them,” she said.

This protein is called immunoglobulin E, and is an antibody associated with food allergies. When it encounters a specific allergen, it causes immune cells to release chemicals such as histamine that lead to an allergic reaction, the article states.

While acquiring allergies from a blood donor is rare, this is not the first time a case like this has been reported. In fact, in 2007 an 80-year-old woman had an anaphylactic reaction to peanuts after she received a blood donation from a 19-year-old donor who also has a peanut allergy. This appears to be the same in this case, as research conducted by Canadian Blood Services found that the child’s donor has an allergy to nuts, fish and shellfish.

However, because the boy’s body itself did not make such antibodies against fish and nuts, his doctors said they suspected his allergies would go away within a few months, which they recently found out to be true.

Five months after the boy experienced the allergic reactions, blood tests showed that the boy’s immunoglobulin E levels to salmon and peanut were undetectable. Then, after six months, his parents had gradually and successfully reintroduced nuts and fish back into their son’s diet.

It’s unclear how doctors could prevent future cases, Upton said in the article, as neither Canadian nor American blood service organizations bar people with allergies from donating blood. Also, testing donated blood for levels of immunoglobulin E doesn’t always predict allergies. In fact, some people with high levels of immunoglobulin E don’t have any allergies, and others with low levels of the protein do.

“Clearly, the safety of the [blood] supply is of everyone’s utmost concern,” but more research is needed to determine how best to avoid the transfer of allergies, and how frequently this happens, Upton said.

For more information, click here.

Comments are closed.