Amyloid A amyloidosis secondary to rheumatoid arthritis: pathophysiology and treatments.

The introduction of biological therapies targeting specific inflammatory mediators revolutionised the treatment of rheumatoid arthritis (RA). Targeting key components of the immune system allows efficient suppression of the pathological inflammatory cascade that leads to RA symptoms and subsequent joint destruction. Reactive amyloid A (AA) amyloidosis, one of the most severe complications of RA, is a serious, potentially life-threatening disorder caused by deposition of AA amyloid fibrils in multiple organs. These AA amyloid fibrils derive from the circulatory acute-phase reactant serum amyloid A protein (SAA), and may be controlled by treatment. New biologics may permit AA amyloidosis secondary to RA to become a treatable, manageable disease. Rheumatologists, when diagnosing and treating patients with AA amyloidosis secondary to RA, must understand the pathophysiology and clinical factors related to development and progression of the disease, including genetic predisposition and biological versatility of SAA.