AA amyloidosis (previously known as secondary amyloidosis) is characterized by the extracellular deposition of serum amyloid A containing fibrils, which is synthesized in the liver. Serum amyloid A is an acute phase reactant and is most strongly associated with chronic inflammatory diseases such as rheumatoid arthritis, ankylosing spondylitis, juvenile idiopathic arthritis, inflammatory bowel disease, psoriatic arthritis, familial Mediterranean fever, malignancies, chronic infections, and intravenous drug abuse. AA amyloidosis has become less common in the past century due to improvement in diagnosis and therapy of chronic inflammatory diseases and infections.

The clinical presentation of AA amyloidosis is dependent on which organ systems are affected. The kidneys are affected the majority of the time (90% of the time), and proteinuria is usually the first clinical manifestation; 50% of affected patients present with nephrotic syndrome. Untreated AA amyloidosis can lead to end-stage renal disease. The liver and heart are other major sites of amyloid deposition. Gastrointestinal (GI) amyloidosis is also more common in AA amyloidosis, present in 10%-70% of patients depending on series.

Signs and symptoms of AA amyloidosis include arrhythmia, dysphagia, dyspnea, anasarca, fatigue, numbness in hands and feet, rash, easy bruising, swollen tongue or uvula, weak grip, weight loss, diarrhea, GI tract bleeding, proteinuria, hepatomegaly, and splenomegaly.

The hallmark of treatment for AA amyloidosis is treating the underlying inflammatory disease process.

Related topic: AL amyloidosis