Transfusion Reactions

A 58-year-old man with chronic kidney disease (hemoglobin 7.2 g/dL) receives 2 units of packed red blood cells for symptomatic anemia. Within 15 minutes of transfusion initiation, he develops fever (38.5°C), rigors, and back pain. Vital signs show BP 110/70 mmHg, HR 110/min, RR 22/min. Urine output drops to 0.3 mL/kg/hr and becomes dark brown. Serum creatinine rises from 2.8 to 3.4 mg/dL within 2 hours. Direct antiglobulin test (DAT/Coombs) is positive. What is the most likely diagnosis?

A 42-year-old woman with thalassemia major receives her 50th transfusion of packed red blood cells. Two hours after transfusion begins, she develops fever (38.2°C), mild dyspnea, and a dry cough. Examination reveals bilateral fine crackles at the lung bases and oxygen saturation of 88% on room air. Chest X-ray shows bilateral pulmonary infiltrates without cardiomegaly. Echocardiography is normal. Direct antiglobulin test (DAT) is negative. What is the most likely diagnosis?

Which of the following is the most common cause of acute hemolytic transfusion reaction?

Which cytokine is primarily responsible for the pathogenesis of febrile non-hemolytic transfusion reaction (FNHTR)?