korean adolescent patient with manifestations of lymphocyte variant hypereosinophilic syndrome and episodic angioedema with eosinophilia, treated with reslizumab

A four-year-old female patient visited the pediatric hematologic clinic due to periodic generalized edema and eosinophilia. laboratory assessment showed an eosinophil count of 40.02×10^9/l (73.6% of white blood cells). a bone marrow aspirate smear film showed no signs of malignant cells but had hypercellular marrow particles with eosinophilia (45% of all nucleated cells) and 52% of eosinophils were immature. other laboratory tests showed an increased igm level of 827 mg/dl, and lymphocyte phenotyping by flow cytometry revealed an aberrant cd3−cd4+ t-cell population of 27–53×109/l (1.9–3.6% of lymphocytes). polymerase chain reaction analysis for the t-cell receptor gamma gene rearrangement showed a t-cell clonality peak. at the age of 13, allogeneic stem cell transplantation was performed, but with primary rejection. from the age of 17, she has continued receiving 3 mg/kg of reslizumab intravenously every 4 weeks for 21 months. since reslizumab treatment was initiated, her eosinophil count remained consistently within the normal range. this is the first report describing the effective use of reslizumab in a korean adolescent patient for the management of lymphocytic-variant hypereosinophilic syndrome (l-hes). since the patient showed clinical manifestations of l-hes as well as episodic angioedema with eosinophilia (eae), a continuous periodic examination is required given the higher risk of developing lymphoma or leukemia.