Inflammatory Markers: Serum Amyloid A, Fibrinogen and C-Reactive Protein — A Revisited Study

Abstract

The acute phase response is the part of the innate defence system of an animal against trauma, inflammation or infection. During this response, there is increased production and release of certain plasma proteins known as acute phase proteins, which include C-reactive protein (CRP), serum amyloid A (SAA) and fibrinogen (Fg). CRP consists of five identical subunits of 206 amino acids with a molecular weight of approximately 23 kDa. There is strong evidence from numerous studies that CRP is a predictor of inflammation. The acute-phase protein serum amyloid A (SAA) is a clinically useful marker of inflammation. SAA plays not only an important role in the development of AA amyloidosis (an important complication of rheumatoid arthritis) but also interacts with events closely involved in the metabolic syndrome as a high- and low-grade inflammatory modulator. Fibrinogen (Fg) is a high molecular weight plasma adhesion protein and is a biomarker of inflammation. It is synthesized and assembled in hepatocytes and fibroblasts and when secreted into the circulation, its plasma half-life ranges from 3 to 4 days. Several cytokines, are involved in the induction of acute phase protein synthesis, but the mutual importance of these cytokines seems to be cell-type specific and to vary in various experimental settings. Here we revisited the classic acute phase proteins SAA, C-Reactive protein and fibrinogen in their role in inflammation and their interrelationship with some cytokines.

Changes in the sera levels of amyloid A protein in the course of influenza, chickenpox and infectious mononucleosis

“…It is known that the mentioned three laboratory markers do not react (or they react within narrow limits) in the course of a viral inflammation. So, our results are similar to those published by some authors, who indicate SAA is a sensitive acute phase protein, which increases during minor inflammatory stimuli induced by different viruses (7,8,9). Table 5 shows all the complications we registered in our patients.…”

Endothelial Cells, Cholesterol, Cytokines, and Aging

“…Injury to the vessel wall leads to intimal smooth muscle cell proliferation and luminal occlusion. In addition, accumulation oflipids in the vascular endothelium activates complement and triggers intravascular thrombosis and necrosis of the vessel wall (66)(67)(68)(69)(70).…”

IL-37 (IL-1F7) the Newest Anti-Inflammatory Cytokine Which Suppresses Immune Responses and Inflammation

“…Numerous novel cytokine activities with pathogenetic potential have now been demonstrated in inflammatory diseases, including members of the IL-l superfamily (1)(2)(3)(4)(5)(6)(7). However, the etiology of inflammatory diseases is not completely understood.…”