What are the causes of post-transfusion fever (Pyrexia)?

From the Guidelines

Fever after a blood transfusion is most commonly caused by a febrile non-hemolytic transfusion reaction, which occurs in approximately 1.1% of transfusions with prestorage leukoreduction 1. The causes of post-transfusion fever (pyrexia) can be multifactorial, including:

• Febrile non-hemolytic transfusion reactions (FNHTR)
• Bacterial contamination of the blood product
• Transfusion-associated bacteremia
• Cytomegalovirus (CMV) transmission
• Other infectious causes, such as otitis media, decubitus ulcers, or perineal abscesses

Key Considerations

When evaluating a patient with post-transfusion fever, it is essential to consider the timing, associated symptoms, and severity of the fever to determine the specific type of reaction and appropriate treatment.

• FNHTR is the most common cause of post-transfusion fever, occurring in approximately 1.1% of transfusions with prestorage leukoreduction 1.
• Bacterial contamination of the blood product is a rare but potentially life-threatening cause of post-transfusion fever, and should be suspected if patients experience severe febrile reactions during or shortly after platelet transfusions 1.
• CMV transmission can cause a mononucleosis syndrome, characterized by high fever, pancytopenia, and atypical lymphocytosis, particularly in immunocompromised patients 1.

Management

Treatment of post-transfusion fever depends on the underlying cause and severity of the reaction.

• Mild reactions may be managed with acetaminophen (325-650mg orally every 4-6 hours) and monitoring of vital signs.
• Severe reactions may require oxygen, IV fluids, antihistamines, or corticosteroids, and in some cases, vasopressors, mechanical ventilation, or dialysis. It is crucial to inform healthcare providers about previous transfusion reactions to help prevent future complications.

From the Research

Causes of Post-Transfusion Fever (Pyrexia)

The causes of post-transfusion fever, also known as febrile nonhemolytic transfusion reactions (FNHTRs), can be attributed to several factors, including:

• Immune pathways, associated with antibodies against human leukocyte antigen (HLA) produced in transfused patients 2
• Non-immune pathways, associated with cytokines released from blood products during storage 2
• Presence of leukocytes in blood products, which can lead to the release of pro-inflammatory cytokines during storage 3, 4, 5
• Patient-related factors, such as a history of multiple blood transfusions, primary hematologic disease, and malignant disease 2

Risk Factors for Post-Transfusion Fever

Certain patient populations are at a higher risk of developing post-transfusion fever, including:

• Women with a reproductive history 2
• Patients with a history of multiple blood transfusions 2
• Patients with primary hematologic disease or malignant disease 2
• Patients who receive transfusions with over 6 units of leukocyte-depleted packed red blood cells 2

Prevention and Mitigation Strategies

Several strategies can be employed to prevent or mitigate post-transfusion fever, including:

• Leukoreduction, which involves removing leukocytes from blood products before storage 3, 4, 5
• Prestorage leukoreduction, which has been shown to significantly reduce the rate of FNHTRs 5
• Use of additive solutions and plasma reduction 4
• Patient blood management programs 4