Acquired Thrombotic Thrombocytopenic Purpura in a 5-Year-old Child With Wiskott-Aldrich Syndrome

Thrombocytopenia is often seen as a laboratory finding during childhood. A supposed idiopathic thrombocytopenic purpura patient who was later diagnosed as Wiskott-Aldrich syndrome (WAS) and developed acquired thrombotic thrombocytopenic purpura (aTTP). Although autoimmune manifestations in WAS described, aTTP was reported just once. Five-year-old-boy was initially brought with cough, bloody stool (diarrhea), oral mucosal bleeding at 12th months of age. Following diagnosed with idiopathic thrombocytopenic purpura and receiving intravenous immunoglobulin, platelet count raised from 20,000 to 50,000/µL. One year after WAS diagnosis by mutation analysis, he presented with complaints of resistant fever, epistaxis, and melena. Hemoglobin decreased from 10 to 5.9 g/dL. Schistocytes in peripheral blood smear and high anti-ADAMTS-13 antibody level indicated development of aTTP.