Serum amyloid A (SAA) is a family of proteins produced in the liver which are elevated in an acute-phase response. SAA3 is a member of this family that can be produced extrahepatically in inflammatory tissue by macrophages. SAA depositions are found in the granulomas in sarcoidosis patients.

AP makes up 14% of the dry mass of amyloid deposits [8] and is thought to be an important contributor to the pathogenesis of a related group of diseases called the amyloidosis [9].

Amyloid is an abnormal protein that is produced in your bone marrow and can be deposited in any tissue or organ. Amyloidosis frequently affects the heart, kidneys, liver, spleen, nervous system and digestive tract. It is often overlooked because it may cause no symptoms at first.

Amyloid plaques are aggregates of misfolded proteins that form in the spaces between nerve cells. These abnormally configured proteins are thought to play a central role in Alzheimer’s disease. The amyloid plaques first develop in the areas of the brain concerned with memory and other cognitive functions.

Amyloid fibrils are formed by normally soluble proteins, which assemble to form insoluble fibers that are resistant to degradation. Their formation can accompany disease and each disease is characterized by a specfic protein or peptide that aggregates.

After secretion into the circulation, it associates with high-density lipoprotein (HDL) particles. During acute inflammation, serum SAA levels may rise up to 1000-fold, and under these conditions, SAA displaces apolipoprotein A-I from HDL, thus becoming the major apolipoprotein of circulating HDL3.

AA amyloidosis occurs when Serum Protein A levels in the bloodstream remain high for a long period of time. This can be seen in chronic (long-term) inflammatory conditions such as rheumatoid arthritis, inflammatory bowel disease (Crohn’s disease, ulcerative colitis), and chronic infections.

Acute-phase proteins are part of the innate immune response and its biological function, although variable, generally relate to defense to pathological damage and restoration of homeostasis. However, a specific APP may have both pro- and anti-inflammatory effects.

The APP gene provides instructions for making a protein called amyloid precursor protein. This protein is found in many tissues and organs, including the brain and spinal cord (central nervous system). Little is known about the function of amyloid precursor protein.

The amyloid precursor protein (APP) is a transmembrane protein that plays major roles in the regulation of several important cellular functions, especially in the nervous system, where it is involved in synaptogenesis and synaptic plasticity.

Serum amyloid p component binds to late apoptotic cells and is involved in the phagocytosis of these cells by human monocyte-derived macrophages. This protein, a non-fibrillar component, causes soluble fibrils to condense into localized fibrillar aggregates with a greatly enhanced local density of fibril entanglements.

APCS amyloid P component, serum [ (human)] The protein encoded by this gene is a glycoprotein, belonging to the pentraxin family of proteins, which has a characteristic pentameric organization. These family members have considerable sequence homology which is thought to be the result of gene duplication.

Amyloid P component (AP) has been identified in all forms of amyloid as a molecule independent of the amyloid fibril but nonetheless intimately bound to it. AP is a glycoprotein of molecular weight 22 kDa in its monomeric form. It circulates as SAP (serum amyloid P component), a pentraxin composed of two pentameric units.

Serum amyloid P component binding to Shiga toxin 2 requires both a subunit and B pentamer. A possible role of SAP in either host resistance or viral virulence was investigated during influenza infection in vivo. Influenza virus infection is not affected by serum amyloid P component.Human SAP binds much more avidly than mouse SAP to the virus.