What is a Febrile Non-Hemolytic Transfusion Reaction (FNHTR)?
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Febrile Non-Hemolytic Transfusion Reaction (FNHTR) is a common adverse reaction to blood transfusion. It is characterized by an increase in body temperature and chills occurring during or within a few hours after the transfusion. Unlike hemolytic reactions, FNHTRs do not involve the destruction of transfused red blood cells. Rather, they are thought to be caused by the recipient's immune response to white blood cell fragments or cytokines present in the donor blood.
How are FNHTRs Related to Infectious Diseases?
FNHTRs are often confused with
infectious transfusion reactions, which are caused by pathogens like bacteria, viruses, or parasites contaminating the blood product. However, FNHTRs are non-infectious. The fever associated with FNHTRs can mimic febrile responses seen in infectious diseases, leading to unnecessary antibiotic treatments unless the cause is correctly identified.
What Causes FNHTRs?
The primary cause of FNHTRs is the presence of
cytokines and white blood cell fragments in the transfused blood product. During storage, cytokines accumulate, particularly in platelet and red blood cell concentrates. When these blood components are transfused, they can trigger an immune response in the recipient, leading to fever and chills. Another contributory factor may be the presence of antibodies in the recipient that react with antigens on donor leukocytes.
How are FNHTRs Diagnosed?
Diagnosis of FNHTRs is mainly clinical, based on the temporal relationship between the transfusion and the onset of symptoms. Healthcare providers should rule out other serious causes of fever following a transfusion, such as
hemolytic transfusion reactions or bacterial contamination. Laboratory tests, including a direct antiglobulin test (DAT) and blood cultures, may be performed to exclude these other conditions.
What are the Symptoms of FNHTRs?
Common symptoms include a rise in body temperature of at least 1°C (1.8°F) from baseline, chills, and general malaise. These symptoms typically appear during or shortly after the transfusion and are self-limiting, usually resolving within a few hours. In some cases, patients may also experience mild respiratory distress or anxiety.
How are FNHTRs Managed?
Management of FNHTRs primarily involves symptomatic treatment.
Antipyretics such as acetaminophen are commonly administered to manage fever and chills. It is essential to stop the transfusion immediately once a reaction is suspected to assess the severity and rule out other complications. Resumption of transfusion may be considered once the reaction is confirmed to be non-hemolytic and benign.
Can FNHTRs be Prevented?
Prevention strategies for FNHTRs focus on reducing the leukocyte content in blood products.
Leukoreduction, a process that removes white blood cells from blood components, is effective in decreasing the incidence of FNHTRs. Additionally, using fresher blood products with lower cytokine accumulation may also mitigate the risk. Pre-transfusion medication with antipyretics has been used, but its efficacy is variable.
What is the Prognosis for Patients with FNHTRs?
The prognosis for patients experiencing FNHTRs is generally excellent, as these reactions are benign and self-limiting. They rarely result in any long-term complications. However, they can cause discomfort and anxiety for the patient and may lead to delays in receiving necessary transfusions. Proper diagnosis and management are crucial to minimizing these adverse effects.
Conclusion
FNHTRs represent a significant, yet non-threatening, complication of blood transfusion. Understanding the distinction between FNHTRs and infectious transfusion reactions is vital for appropriate management. Continued efforts in transfusion medicine, such as leukoreduction and improved donor screening, are essential for reducing the incidence of FNHTRs and ensuring the safety and efficacy of blood transfusions.
