Secondary (
AA) amyloidosis is a multisystem disorder complicating
chronic infections or inflammatory diseases. It is characterized by extracellular deposit of fibrils composed of fragments of
serum amyloid A (SAA), an
acute phase reactant protein. The kidney is the most frequent organ involved, manifesting as progressive
proteinuria and renal impairment. Attenuation of the level of circulating SAA
protein by treating the underlying inflammatory condition remains the primary strategy in treating
AA amyloidosis. However, at times, achieving adequate control of
protein production can prove difficult. In addition, relapse of renal function often occurs rapidly following any subsequent inflammatory stimulus in patients with existing
amyloidosis. Recently there has been an interest in finding other potential strategies targeting
amyloid deposits themselves.
Eprodisate is a sulfonated molecule with a structure similar to
heparan sulfate. It competitively binds to the
glycosaminoglycan-binding sites on SAA and inhibits fibril polymerization and
amyloid deposition. Recent randomized clinical trial showed that it may slow down progressive
renal failure in patients with
AA amyloidosis. However confirmatory studies are needed and results of a second Phase III study are eagerly awaited to clarify whether or not
eprodisate has a place in treating renal
amyloid disease.