RESOLUTION OF MILK-PROTEIN ALLERGY AFTER HEMATOPOIETIC STEM CELL TRANSPLANT IN A PATIENT WITH IPEX SYNDROME

Abstract

Introduction Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is due to a FOXP3 gene mutation leading to regulatory T cell dysfunction and multi-organ autoimmunity. Patients present in infancy with protracted diarrhea, dermatitis, insulin-dependent diabetes mellitus, and thyroiditis. Some patients may have severe food allergies. We present a patient with IPEX syndrome whose milk protein allergy resolved after receiving a stem cell transplant for his primary immunodeficiency. Case Description A 32-month-old male, with a history of IPEX syndrome presented for evaluation of food allergies. Prior to receiving a stem cell transplant to correct his primary immunodeficiency, the patient was diagnosed with a milk protein allergy by skin testing after developing skin rashes. ImmunoCAP testing was negative to seafood, tree nuts, peanuts, soy, and sesame. Wheat, egg, and cow's milk were weakly positive. Total IgE was 16 (Normal: 0-115 kU/L). Skin testing was negative for wheat, egg, cow's milk, and peanuts. All foods were introduced into the patient's diet, after which good tolerance of milk and improved bowel function. Discussion IPEX syndrome is a rare recessive disorder of early childhood. Stem cell transplantation is the only curative therapy available. Patients with IPEX, who also have food allergies, may experience complete symptom resolution after a stem cell transplant. This is thought to be due to reconstitution of a properly regulated immune system after ablative conditioning.This case illustrates how stem cell transplantation may lead to resolution of food allergies and improvement in enteritis symptoms in a patient with IPEX syndrome.