Peanut allergy risks from blood transfusion

A report in a recent issue of The New England Journal of Medicine describes an apparent allergic reaction to peanuts that was suffered by a six year old boy while receiving a blood transfusion as part of his cancer treatment.

During the transfusion, the boy developed anaphylactic symptoms including a rash, angioedema, hypotension, and difficulty breathing. After treatment with adrenaline, he recovered within half an hour. The boy's mother reported that her son had had a similar reaction after eating peanuts at the age of 1 year and peanuts had been excluded from his diet thereafter.

Investigations into the cause of the reaction were made, with the blood donors contacted and questioned. Three of the five blood donors recalled eating several handfuls of peanuts the evening before donation. As the major peanut allergen, Ara h2, is extremely resistant to digestion, the clinicians investigated whether the peanuts ingested by the donors could have been passed on to the patient in the transfused blood products.

The patient's peanut reactivity was confirmed through measurements of serum levels of peanut-specific IgE. These were found to be greatly elevated following the transfusion and therefore supportive of the hypothesis that the consumption of peanuts by the donors before blood donation provided the trigger for the patient's transfusion reaction.

The authors suggest consideration of donor-ingested allergens is worthy when transfusing sensitized patients.

Reference: Jacobs et al. 2011. The New England Journal of Medicine. Vol. 364 pp. 20