The term
amyloid describes the deposition in the extracellular space of certain
proteins in a highly characteristic, insoluble fibrillar form.
Amyloidosis describes the various clinical syndromes that occur as a result of damage by
amyloid deposits in tissues and organs throughout the body. The clinical significance of
amyloid varies enormously, ranging from incidental asymptomatic deposits to localized disease through to rapidly fatal systemic forms that can affect multiple vital organs. Currently available
therapy is focused on reducing the supply of the respective
amyloid fibril precursor
protein and supportive medical care, which together have greatly improved survival.
Chemotherapy and anti-inflammatory treatment for the disorders that underlie AL and
AA amyloidosis are guided by serial measurements of the respective circulating
amyloid precursor
proteins, i.e. serial serum free light chains in AL and
serum amyloid A protein in AA type. Quality of life and prognosis of some forms of hereditary systemic
amyloidosis can be improved by liver and other organ transplants. Various new
therapies, ranging from silencing
RNA,
protein stabilizers to
monoclonal antibodies, aimed at inhibiting fibril precursor supply, fibril formation or the persistence of
amyloid deposits, are in development; some are already in clinical phase.