Most common cause of febrile non haemolytic transfusion reaction?
**Core Concept**
Febrile non-haemolytic transfusion reactions (FNHTRs) are a type of adverse reaction to blood transfusion characterized by an increase in body temperature, typically above 38°C, without evidence of haemolysis. This reaction is often caused by the introduction of cytokines and other inflammatory mediators into the recipient's circulation.
**Why the Correct Answer is Right**
The most common cause of FNHTR is the transfusion of white blood cells (WBCs), particularly neutrophils, from the donor's blood. When WBCs are transfused, they can release cytokines, such as interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-α), which stimulate the recipient's immune system and cause an inflammatory response. This leads to fever, which is often accompanied by chills, sweating, and other systemic symptoms. The presence of WBCs in the transfused blood is a key factor in the development of FNHTR.
**Why Each Wrong Option is Incorrect**
**Option A:** Plasma is not a common cause of FNHTR, as it is a component of blood that is separated from WBCs during the blood banking process. While plasma can contain some cytokines, it is not a primary contributor to FNHTR.
**Option B:** Antibodies to RhD antigen are associated with haemolytic transfusion reactions, not FNHTR. These antibodies can cause the destruction of red blood cells, leading to a more severe reaction.
**Option C:** Platelets can also contribute to FNHTR, particularly if they are transfused with WBCs. However, they are not the most common cause of this reaction.
**Clinical Pearl / High-Yield Fact**
To minimize the risk of FNHTR, blood banks often use white blood cell reduction techniques, such as filtration or washing, to remove WBCs from the transfused blood. This can help reduce the incidence of FNHTR and make transfusions safer for patients.
**Correct Answer:** D.