Serum amyloid A1 (SAA1)

Serum amyloid A1.1 (SAA1.1) is an isoform of the human serum amyloid A1 protein, encoded by the SAA1 gene, and is a variant defined by single nucleotide polymorphisms in the coding sequence[1][2]. Serum amyloid A1 (SAA1) is a major acute-phase protein produced predominantly by hepatocytes in response to inflammatory stimuli, infection, or malignancy[1]. SAA1.1 is one of several allelic variants, differing by minor amino acid substitutions, defined by SNPs[2]. During inflammation, SAA1 rapidly increases and associates with HDL, displacing ApoA-I and modifying lipid metabolism[1][4]. Elevated SAA1 is a reliable biomarker for several diseases, especially chronic inflammation, amyloidosis, and certain malignancies[1][5]. SAA1.1 forms a hexameric structure and is a significant precursor for amyloid A deposits[2], implicated in tissue amyloidosis when chronically elevated. Its exact biological roles continue to be investigated, but it is well established as a mediator of the acute-phase response and immune signaling[1][5][2]. Its genetic polymorphisms (including SAA1.1) have been linked to disease susceptibility, such as amyloidosis and cardiovascular disease[2][5].

Other names

Apolipoprotein SAASerum amyloid A proteinSAAAA protein precursor

Drugs may act by reducing SAA1 levels (inhibition of acute-phase response for inflammation/amyloidosis) Indirect modulation through anti-inflammatory pathways (IL-1, IL-6, TNF-α)