A 24-year-old Caucasian woman is transferred from an outside hospital for “confusion, hematuria and fever”. She was found to have a hemoglobin value of 7 g/dL, WBC count 9 x 109/L, and platelet count 25 x 109/L. Her past medical history is unremarkable. She was transfused with one platelet unit at the outside hospital. She has one child and no history of abortions, transfusion or transplantation.