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Amyloidosis reactive to chronic inflammation (AA amyloidosis) is a rare type of systemic amyloidosis, with prevalent renal involvement and a generally good overall survival (OS). However, progression to end-stage renal failure is frequent. Compared to other types of systemic amyloidosis, the role of prognostic biomarkers has been poorly explored in AA amyloidosis. Moreover, validated staging systems for the identification of patients with a more advanced disease are lacking. The acute phase reactant serum amyloid A (SAA) is the amyloid precursor protein and its concentration is associated with outcome. SAA concentration <10 mg/L after treatment translates in longer OS and lower incidence of end-stage renal failure. Boston researchers proposed a staging system for OS using estimated glomerular filtration rate (eGFR; cut-off, <35 mL/min/1.73 m2) and erythrocyte sedimentation rate (ESR; cut-off, >80 mm/h). Although it lacks validation, this staging system identified three groups with significant different OS. Pavia and Heidelberg researchers identified and validated a staging system for OS based on eGFR (cut-off, <45 mL/min/1.73 m2), serum albumin (cutoff, <30 g/L) and natriuretic peptides [type-B natriuretic peptide (BNP)] cut-off, >130 ng/L and/or N-terminal BNP (NT-proBNP) cut-off, >1000 ng/L). This staging system identified patients with low risk (5-year survival rate: 84%), intermediate risk (5-year survival rate: 55%) and high risk (5-year survival rate: 12%). Moreover, they proposed and validated a renal staging system using proteinuria (cut-off, >3 g/24h) and eGFR (cut-off, <35 mL/min/1.73m2). These data confirm the central role of the clinical laboratory in clinical management of systemic AA amyloidosis. [ABSTRACT FROM AUTHOR]