Acute phase reaction refers to a series of immediate physiological and systemic responses that occur in the body in response to inflammation, infection, trauma, or tissue injury. It is often characterized by a rapid and robust activation of the immune and inflammatory systems, aiming to eliminate the cause and promote tissue repair.
During an acute phase reaction, various changes take place in the body. Firstly, the liver plays a crucial role by producing and releasing a range of acute phase proteins (such as C-reactive protein and fibrinogen) into the bloodstream. These proteins act as essential mediators of the immune response, helping to enhance phagocytosis, promote tissue healing, and neutralize pathogens.
Additionally, there is an increase in the production of pro-inflammatory cytokines, including interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). These cytokines play an active role in activating other immune cells and inducing fever, which is a common manifestation of acute phase reactions.
The acute phase reaction also leads to changes in the composition of white blood cells, with a shift towards an increased number of neutrophils and a decreased number of lymphocytes. This change aids in enhancing the body's ability to fight infections.
Overall, the acute phase reaction is a complex and coordinated response aimed at mounting an effective defense against tissue damage or loss, infection, or inflammation. While it is a normal and necessary part of the immune response, excessive or prolonged acute phase reactions can lead to chronic inflammation and tissue damage, highlighting the importance of maintaining a balanced and regulated response.
