Patient reacts to peanut after receiving transplanted lung from donor with allergy history

After receiving a lung from a donor with known peanut allergy, a transplant patient with no history of allergy developed a temporary sensitization to peanut, according to a case study published in Annals of Allergy, Asthma & Immunology.

This case suggests that IgE-mediated food allergies acquired from a donor through solid organ transplants may be transient, Stephanie Stojanovic, MBBS, registrar in allergy, asthma and clinical immunology at Alfred Hospital in Melbourne, Australia, and colleagues wrote in the study.

The transplant patient was a man, aged 50 years, with end-stage chronic lung allograft dysfunction who received a second lung transplant. The donor, aged 16 years, had known asthma and peanut allergy with previous anaphylaxis.

Sixteen days after the procedure, the recipient ingested peanut and became acutely dyspnoeic within 5 minutes. By the time emergency medical services (EMS) arrived, he was hypoxic with wheeze, and his oxygen saturation was 56% on room air. He also was tachycardic to 133 beats per minute but normotensive, and there were no cutaneous manifestations of IgE-mediated allergy.

EMS administered 0.5 mg of intramuscular adrenaline and provided IV fluid resuscitation as well as nebulized bronchodilators to stabilize the patient. But 56 minutes later, rebound anaphylaxis developed.

EMS treatment then included an IV bolus of 5 mcg of adrenaline with infusion at 5 mcg/minute. Upon arrival at the ED, the adrenaline dose was escalated along with administration of IV hydrocortisone and H1 antagonists.

Improvement followed admission to the ICU, where the patient was weaned from and stopped receiving the adrenaline infusion over the next 12 hours.

The providers noted that 2 hours after symptom onset, the patient’s serum tryptase was 10 mcg/L, which fell to 3.1 mcg/L by 24 hours after onset. Prior to the transplant, the patient had a baseline serum tryptase of 4.3 mcg/L.

A week before this reaction, the patient had experienced an episode of acute wheeze after ingesting peanuts. This reaction responded to inhaled short-acting bronchodilators. Otherwise, the patient had no history of allergy and had eaten peanuts and peanut products as part of his diet frequently.

The patient then practiced strict peanut avoidance, and markers of peanut sensitization were closely monitored. Negative skin testing to peanut with undetectable serum peanut-specific IgE followed based on re-evaluation.

Eighteen months after the transplant, a supervised graded oral challenge to a cumulative dose of 4 teaspoons of peanut butter was negative. Also, a follow-up phone call 12 months after that confirmed sustained peanut tolerance.

The authors suggested two possible mechanisms behind this reaction.

First, they wrote, there may be a passive transfer of peanut sIgE via sensitized donor mast cells and/or basophils. The transient nature of this patient’s reaction suggests an absence of ongoing active peanut sIgE production and gradual depletion of the cells transferred to the patient, they added.

Second, the authors wrote, B lymphocytes that produce peanut sIgE or peanut-specific Th2 lymphocytes may be transferred into the recipient during the transplant, adding that the positivity of the patient’s serum peanut sIgE and peanut skin prick tests support this possibility.

Additionally, the authors noted that the patient had been immunosuppressed with tacrolimus for 5 years before the procedure and that the shift toward predominant Th2 over Th1 responses should be considered.

Citing the rising prevalence of food allergy, the authors called for vigilance to mitigate risks for morbidity and mortality from acquired donor allergic disease following solid organ transplants.

Screening for donor food allergy in addition to early allergy specialist assessment and education for at-risk recipients could prevent fatal outcomes, the authors continued. When acquired sensitization does happen, supervised graded oral challenges may enable definitive de-labeling and dietary reintroduction.