A 35-year-old woman is rushed to the emergency department after a major car accident. She has sustained multiple fractures and internal injuries, with significant blood loss. Her initial hemoglobin is 6.2 g/dL, and a massive transfusion protocol is initiated using O-negative blood. Shortly after the transfusion, she develops fever, chills, hematuria, hypotension, and respiratory distress. Blood typing later reveals she has the Oh (Bombay) phenotype. What is the cause of this adverse reaction?
