Serum amyloid A
Chromosome 11
Serum amyloid A (SAA) proteins are a family of apolipoproteins associated with high-density lipoprotein (HDL) in plasma.
Different isoforms of SAA are expressed in response to inflammatory stimuli (acute phase SAAs), and these proteins are produced predominantly by the liver.
Acute-phase serum amyloid A proteins (A-SAAs) are secreted during the acute phase of inflammation.
Acute phase proteins transport of cholesterol to the liver for secretion into the bile, the recruit immune cells to inflammatory sites, and the induce enzymes that degrade extracellular matrix.
A-SAAs are implicated in several chronic inflammatory diseases, such as amyloidosis, atherosclerosis, and rheumatoid arthritis.
Three A-SAA genes have been identified in human.
Serum amyloid A (SAA) an acute phase marker that responds rapidly, increasing within hours after inflammatory stimulus, and the magnitude of increase may be greater than that of CRP.
SAA levels may correlate better with disease activity in early inflammatory joint disease than do ESR and CRP.
Although largely produced by hepatocytes SAA is also produced by adipocytes as well, and its serum concentration is associated with body mass index.
Serum amyloid refers to a group of proteins in the blood that can be measured as indicators of various health conditions.
There are two main types of serum amyloid proteins that are commonly discussed:
1. Serum Amyloid A (SAA) is an acute-phase protein produced primarily by the liver.
SAA is a sensitive marker of inflammation and infection.
Normal levels are typically very low, but increase dramatically up to 1000-fold during an acute inflammation.
Elevated SAA levels are associated with various conditions including infections, autoimmune diseases, and certain cancers.
2. Serum Amyloid P (SAP)
SAP is a glycoprotein that’s part of the pentraxin family, involved in the innate immune system and can bind to various substances in the body.
SAP levels don’t fluctuate as dramatically as SAA in response to inflammation.
Measuring serum amyloid levels, particularly SAA, are used to monitor disease activity in inflammatory conditions like rheumatoid arthritis.
Helps assess the risk of complications in conditions like familial Mediterranean fever, and evaluate the effectiveness of treatments for inflammatory diseases.