A study now published in the Journal of the European Academy of Dermatology and Venereology, is reportedly the first documented account of an allergy transfer between a donor and recipient of a bone marrow transplant. While this may sound strange, when compared to other obscure traits reportedly transferred between organ donors and recipients, it’s pretty basic.

The study, conducted by researchers from the University of Munich in Germany, focuses on the case of a 46-year-old male patient who experienced his first ever episode of having an allergic reaction to kiwis following a bone marrow transplant from his kiwi-allergic sister. During the transplant procedure, doctors extracted hematopoietic stem cells from his sister’s bone marrow and implanted them into her sibling. The initial goal was for the sisters’ healthy cells to repopulate her brother’s depleted blood and immune cells.

And while the operation was a success, the patient developed an immediate “oral allergic symptom” on two occasions upon trying to eat a kiwi. Considering the patient had never experienced any symptoms of kiwi allergy prior to the operation, a technique known as a fluorescent in situ hybridisation (FISH) was done to better determine where the reaction had come from. Using the FISH analysis, the team specifically looked at the siblings’ hematopoietic cells — a type of parent cell that gives rise to other blood cells, Newser reported.

Allergies occur when our immune system accidentally thinks that an innocent substance is a potentially dangerous invader, Medical News Today reported. In the case of a kiwifruit allergy, the immune system mistakes the fruit as a threat and responds with a full-fledged attack. Newser reported that the blood cells are behind this immune reaction, and because most blood cells originate in our marrow, marrow transplants can sometimes result in a transfer of allergies.

The FISH analysis revealed what the team had suspected: All the hematopoietic cells of the male recipient completely originated from the female donor. This proved that the allergy had indeed been transferred from one sibling to another via the marrow transplant. However, according to Dr. Jenny Thomas, co-author of the study, this transference is rare.

“Apart from our case a total of 18 nonallergic recipients were reported to develop allergic disease after transplantation,” Thomas told Medical Daily. “However, conclusive information for transfer was available for only 5 cases. In this regard at least reported cases of allergy transfer are rare.”

Allergies are not the only strange trait suspected of being transferred between organ donors and recipients during a transplant. In 2008, Reuters reported that Demi-Lee Brennan of Australia had changed blood groups entirely after receiving a liver transplant.

"In effect she had had a bone marrow transplant. The majority of her immune system had also switched over to that of the donor," Michael Stormon, a hepatologist who treated Brennan at the Children's Hospital at Westmead, told Reuters.

Some patients have even been reported to have changed their personalities following an organ transplant. A 1992 study published in the Journal of Quality of Life Research interviewed 47 patients who received a heart transplant over a period of two years in Vienna, Austria and found that six percent reported a drastic change in personality due to their new heart.

Even stranger, a patient who took part in a study conducted by the School of Nursing at the University of Hawaii in Honolulu received a heart transplant from a man who was killed by a gunshot to the face and was reported to have dreams of seeing hot flashes of light directly on his face.

According to Thomas, insight into allergic transfers among transplant donors and recipients could have more far-reaching implications.

“More insights into the mechanisms of allergy transfer via HCT (hematopoietic stem cell transplantation) would certainly extend knowledge concerning allergy itself and how allergy is established,” wrote Thomas, adding that the findings may even suggest that one day doctors may consider allergy status for the selection of bone marrow donors “especially concerning severe allergic diseases.”

Source: Garzorz N, Thomas J, Eberlein B, et al. Newly acquired kiwi fruit allergy after bone marrow transplantation from a kiwi-allergic donor. Journal of the European Academy of Dermatology and Venereology. 2016