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Peanut-eating donors spark allergic reaction

Tainted blood Eating peanuts while watching soccer has led to a discovery: What you eat before you give blood may result in a severe allergic reaction in people who receive that blood.

A report in the New England Journal of Medicine concludes that a six-year-old boy who received a transfusion suffered such a reaction because three of the five donors had eaten peanuts the night before their donation.

The researchers say that, for the moment, they are not recommending any changes in blood donation practices.

Yet they also cautioned that similar cases may have occurred and gone unreported.

The child received the transfusion as part of his treatment for acute lymphoblastic leukaemia, a blood cancer. He experienced a rash, low blood pressure, swelling, and difficulty breathing, but recovered following resuscitation.

The mother of the boy recalled that he had had a similar reaction after eating peanuts when he was one year old.

At that point, investigators went back and interviewed the five donors.

Co-author Dr Joannes Jacobs of the Radboud University Nijmegen Medical Center in Nijmegen, the Netherlands, says three reported eating several handfuls of peanuts the evening before the donation.

One of the three provided the plasma portion of the transfusion, he says.

How did the three remember when they had eaten peanuts?

Co-author Dr Elisabeth van Pampus says, "On Sunday evening in the Netherlands, the big thing is to watch soccer on the couch, and some people consume peanuts," so they recalled what they had been snacking on.

First clinical report

The allergic reaction happened, the researchers says, because the major peanut allergen resists digestion, and it also creates another protein that gets into the blood and stays there for up to 24 hours. The boy had antibodies to both.

Jacobs says the theoretical possibility of this happening was suggested in 2003. "This is the first clinical report of this."

Some cases may "have gone unexplained and unreported," the researchers warn.

"We must analyse when this happens and how often it happens," says Jacobs. "We must create awareness that this phenomenon can take place."

Dr Dan Waxman, president of America's Blood Centers and chief medical officer at the Indiana Blood Center, agrees that in the United States, there is a need for a national system to record how often these types of reactions occur.

He suspects that a peanut allergy-related reaction is extremely rare. What may be more of a worry, and what blood banks are addressing, he says, is the case of a patient who is allergic to penicillin, for example, getting a transfusion from someone who was taking the drug.

"We're really good about donor questionnaires about medication these days, or if someone's taking an antibiotic," says Waxman, who was not involved in the new report.

"We ask a certain amount of health history (from donors), but in terms of what people might have eaten, we really don't ask."