Secondary amyloidosis is a form of amyloidosis (see this term), that complicates chronic inflammatory disorders (mainly rheumatoid arthritis, see this term) and is characterized by the aggregation and deposition of amyloid fibrils composed of serum amyloid A protein, an acute phase reactant. Although spleen, suprarenal gland, liver and gut are frequent sites of amyloid deposition, the clinical picture is dominated by renal involvement.

A bacterial infection of the endocardium, the inner layer of the heart, which usually involves the heart valves.