Transient Peanut Allergy Following Solid Organ Transplant

T U E S D A Y 832 Persisting Food Allergen Sensitization after Allogeneic Hematopoietic Stem Cell Transplantation for DOCK8 Deficiency Corinne Savides Happel, MD, Kelly D. Stone, MD, PhD, FAAAAI, Dennis D. Hickstein, MD, Alexandra F. Freeman, MD, Helen C. Su, MD, PhD; NIH/NIAID, Laboratory of Host Defenses, Bethesda, MD, NIH/NIAID, Laboratory of Allergic Diseases, Bethesda, MD, NIH/ NCI, Department of Experimental Transplantation and Immunology, Bethesda, MD, NIH/NIAID, Laboratory of Clinical Infectious Diseases, Bethesda, MD. RATIONALE: DOCK8 deficiency is a combined primary immunodeficiency commonly associated with eczema and clinical food allergy. Previous reports of hematopoietic stem cell transplantation for DOCK8 deficiency have described mixed clinical food allergy outcomes. The leading hypothesis explaining mixed outcomes is that mixed donor chimerism allows for food allergy persistence. METHODS: Among a cohort of 6 patients receiving hematopoietic stem cell transplantation with a reduced intensity myeloablative regimen at the National Institutes of Health, allergy-specific history revealed 2 patients with food allergy-induced anaphylaxis prior to transplantation. Skin prick testing was performed after transplant for relevant food allergens for these 2 patients. Food challenges were not performed. RESULTS: Skin prick testing performed 2 years after transplant for a 27year-old male with history of DOCK8 deficiency and peanut allergy was positive for peanut. Similarly, skin prick testing performed 6 months after transplant for a 10-year-old female with history of DOCK8 deficiency and egg, milk, wheat, and tree nut allergies was positive for milk, egg, wheat, and cashew. Peripheral donor chimerism was 100% in myeloid and lymphoid cells for both patients. CONCLUSIONS: These cases are the first demonstrating food allergen sensitization by skin prick testing in DOCK8 patients after hematopoietic stem cell transplantation, despite 100% donor chimerism in peripheral blood. Food allergy may not be cured by hematopoietic stem cell transplantation, even when full donor chimerism in peripheral blood is achieved.