Febrile non-hemolytic transfusion reaction (FNHTR) is the most common type of

transfusion reaction Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but mod ...

. It is a benign occurrence with symptoms that include

fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

but not directly related with

hemolysis Hemolysis or haemolysis (), also known by several other names, is the rupturing ( lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo ...

. It is caused by

cytokine Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...

release from leukocytes within the donor product as a consequence of white blood cell breakdown .These inflammatory mediators accumulate during the storage of the donated blood, and so the frequency of this reaction increases with the storage length of donated blood. This is in contrast to transfusion-associated acute lung injury, in which the donor plasma has antibodies directed against the recipient HLA antigens, mediating the characteristic lung damage.

Definition

Symptoms must manifest within 4 hours of cessation of the transfusion, and should not be due to another cause such as an underlying infection, bacterial contamination of the blood component, or another type of transfusion reaction, e.g.

acute hemolytic transfusion reaction An acute hemolytic transfusion reaction (AHTR), also called immediate hemolytic transfusion reaction, is a life-threatening reaction to receiving a blood transfusion. AHTRs occur within 24 hours of the transfusion and can be triggered by a few milli ...

. Fever must be at least 38 °C/100.4 °F oral and a change of at least 1 °C/1.8 °F from pre-transfusion value OR chills and/or rigors must be present. The UK hemovigilance system (

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) categorizes the severity of the reaction.

Mild

Fever of at least 38 °C/100.4 °F oral and a change of between 1 and 2 °C from pre-transfusion values but no other symptoms or signs.

Moderate

Fever of at least 39 °C, OR a rise in temperature of at least 2 °C from pre-transfusion values AND/OR other symptoms or signs, including chills (

rigors Chills is a feeling of coldness occurring during a high fever, but sometimes is also a common symptom which occurs alone in specific people. It occurs during fever due to the release of cytokines and prostaglandins as part of the inflammatory ...

), painful muscles ( myalgia), or

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

that are severe enough that the transfusion is stopped.

Severe

Fever of at least 39 °C, OR a rise in temperature of at least 2 °C from pre-transfusion values AND/OR other symptoms or signs, including chills (

), painful muscles ( myalgia), or

that are severe enough that the transfusion is stopped AND requires immediate medical treatment, admission to hospital, or lengthens the duration of hospital admission.

Treatment

Paracetamol has been used in treatment, and

leukoreduction Leukoreduction is the removal of white blood cells (or ''leukocytes'') from the blood or blood components supplied for blood transfusion. After the removal of the leukocytes, the blood product is said to be ''leukoreduced''. Benefits and costs ...

of future transfusions is sometimes performed.

References

External links

{{Transfusion medicine Transfusion reactions Complications of surgical and medical care Transfusion medicine