Should We Screen for Food Allergy Post BMT? a Case Report of Allergy to Tree Nuts Transferred after Bone Marrow Transplantation

Background: Food allergy in children in the United States is estimated to be approximately 8% and increasing yearly with approximately 40% causing severe reactions requiring medical intervention and possibly death. BMT donors are screened for drug and food allergy because concern of potential passive transfer of allergy with hematopoietic stem cell transplantation.

Case report:  We report a case of a 15 year old boy with relapsed AML who underwent matched-related bone marrow transplant from his non-identical twin brother after myeloablative conditioning therapy with Busulfan-Cyclophosphamide. His brother has a history of anaphylaxis to walnuts and pecans with confirmatory skin testing being positive for cashews, filbert nuts, pecans, and walnuts prior to bone marrow transplant. Before transplantation, our patient said he was able to eat tree nuts including walnuts without difficulty.  After the transplant the patient avoided tree nuts and had skin prick testing which showed large positives to tree nuts. Serum specific IgE (sIgE) by Immunocap to tree nuts and peanut at his one year post transplant evaluation showed (Figure 1) he had a > 95% risk for anaphylaxis to walnuts with sIgE positive to all other tested tree nuts and peanut. A diagnostic food challenge was not performed because of this risk.

Conclusion:  Bone marrow transplant physicians should be more mindful of donor reported food allergies and consider referral to an allergist for testing after transplantation as passive transfer of IgE mediated food allergies can occur.  

Figure 1: Results of Serum Specific IgE (Immunocap) testing of tree nuts.

Component	Reference Range
Almond IgE	<0.35 KU/L	3.55 (H)
Almond Class	0	3 (H)
Brazil Nut IgE	<0.35 KU/L	1.28 (H)
Brazil Nut Class	0	2 (H)
Cashew Nut IgE	<0.35 KU/L	3.86 (H)
Cashew Nut Class	0	3 (H)
Hazel Nut IgE	<0.35 KU/L	13.5 (H)
Hazel Nut Class	0	3 (H)
Macadamia Nut IgE	<0.35 KU/L	0.74 (H)
Macadamia Nut Class	0	2 (H)
Peanut IgE	<0.35 KU/L	1.56 (H)
Peanut Class	0	2 (H)
Pecan Nut IgE	<0.35 KU/L	4.68 (H)
Pecan Nut Class	0	3 (H)
Pistachio IgE	<0.35 KU/L	4.16 (H)
Pistachio Class	0	3 (H)
Walnut IgE	<0.35 KU/L	35.60 (H)
Walnut Class	0	4 (H)