Serum amyloid A1-derived amyloid fibrils (AA amyloid)

Serum amyloid A1-derived amyloid fibrils (AA amyloid) are insoluble protein aggregates characterized by a cross-beta sheet structure, formed from the misfolding and proteolytic cleavage of the acute-phase reactant Serum Amyloid A1 (SAA1). SAA1 is produced by the liver in response to chronic inflammatory stimuli, such as rheumatoid arthritis or chronic infections, and its sustained elevation is the primary driver of fibril formation. These fibrils deposit extracellularly in vital organs, most notably the kidneys, liver, and spleen, leading to systemic AA amyloidosis and eventual organ failure. Current therapeutic strategies primarily focus on reducing the precursor SAA1 levels by treating the underlying inflammatory condition with biologics like tocilizumab or TNF inhibitors. Emerging treatments also aim to directly interfere with fibril polymerization using agents like eprodisate or to promote the clearance of existing deposits through antibody-mediated mechanisms. Monitoring SAA levels and renal function is critical for managing disease progression and assessing treatment efficacy.

Other names

Amyloid A proteinAA proteinSAA1-derived fibrilsSecondary amyloidosis fibrilsReactive amyloidosis fibrils

Inhibition of fibril formation by blocking glycosaminoglycan interactions; suppression of precursor SAA1 synthesis through cytokine inhibition; antibody-mediated clearance of existing amyloid deposits.