A 55-year-old man presents to the emergency department with a 10-day history of fatigue, shortness of breath, and lightheadedness with minimal exertion. He is found to have a hemoglobin concentration of 6.7 g/dL. He is consented for a blood transfusion which is started. He is admitted to the hospital for further evaluation. 3 hours after transfusion of 1 unit of packed red blood cells, he develops fever and chills. His temperature is 38.8°C (101.8°F), blood pressure is 118/67 mmHg, pulse is 112/min, respirations are 18/min. On physical examination, he appears pale and has tachycardia. The remainder of the examination shows no abnormalities. His hemoglobin concentration is measured again and is 7.7 g/dL. Direct Coombs test is negative. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and platelet counts are all within normal limits. Urinalysis is unremarkable. Blood cultures are drawn.
E) Release of cytokines from the transfused blood
Release of cytokines from the transfused blood is the most likely cause of this patient’s fever following the transfusion of packed red blood cells. Transfusion reactions are common and can range in severity from mild discomfort (e.g., itching, fever, or mild rash) to life-threatening illness (e.g., hemolysis or anaphylaxis). The time course of this patient’s fever (several hours after the start of the transfusion) and normal laboratory studies to evaluate for a hemolytic transfusion reaction are consistent with an acute febrile nonhemolytic transfusion reaction (FNHTR), which is the most common type of transfusion reaction. FNHTR occurs because of the presence of preformed antibodies on donor leukocyte antigens and from cytokines in the plasma component of the transfused sample. It is typically mild in severity and resolves with supportive care. If symptoms occur during the transfusion, it should be stopped immediately to rule out ABO incompatibility. Antipyretics and consideration of other causes of fever are recommended. Recurrent FNHTR can be prevented through the transfusion of leukodepleted red blood cells.
Answer choice A: Bacterial contamination of the transfused blood, is incorrect. Bacterial contamination of the transfused blood is uncommon, but all potential causes of fever should be evaluated. Bacterial infection is more common after the transfusion of platelets. Bacterial infection as a cause of fever would generally occur later than 2 hours after the start of transfusion and may be accompanied by hypotension.
Answer choice B: Hemolytic transfusion reaction, is incorrect. Hemolytic transfusion reactions usually occur after clerical errors that result in the transfusion of ABO incompatible blood. In these instances, preformed antibodies against antigens on the surface of donor red blood cells lead to widespread hemolysis. This reaction is typically severe and may present with fever, flank pain, hemoglobinuria, and occasionally death. This patient’s laboratory results are not consistent with a hemolytic transfusion reaction.
Answer choice C: HIV infection from transfused blood, is incorrect. HIV infections from transfused blood are far less common in current clinical practice because of the universal screening of donated blood. Additionally, the symptoms of HIV infection would be delayed, and are unlikely to occur within 2 hours of administration of any contaminated blood products.
Answer choice D: IgA deficiency, is incorrect. IgA deficiency can lead to anaphylaxis secondary to pre-formed antibodies against donor immunoglobulins and can be prevented by washing out as much plasma as possible from donor red blood cells. This patient does not have signs or symptoms of anaphylaxis.
Key Learning Point
Acute febrile nonhemolytic transfusion reactions are the most common type of transfusion reaction and typically resolve with supportive care. These reactions occur as a result of preformed antibodies on leukocyte antigens and cytokines from the donor plasma.
