beta(2)-microglobulin-derived amyloidosis: An update

The present review attempts to summarize recent developments in the field o f beta (2)-microglobulin-derived amyloidosis (A beta (2)m amyloidosis) in p atients on chronic dialysis therapy. A key factor in the pathogenesis is th e uremic retention of the precursor molecule, beta (2)-microglobulin (beta (2)m) However, secondary modifications of the molecule such as limited prot eolysis, conformational changes, and the formation of advanced glycation en d products have also been described. Finally, in order to explain the strik ing predilection of the disease for synovial and periarticular structures, a role of local predisposing factors within the synovial membrane (for exam ple, of the particular constituents of the extracellular matrix) must also be postulated. With respect to clinical symptomatology, recent data have co nfirmed that clinically manifest signs of the amyloidosis represent only th e tip of the iceberg, since histologically amyloid deposition is much more widespread. Noninvasive diagnosing of the disease has been advanced by tech nical changes of the beta (2)m scintigraphy. Finally, there is accumulating evidence that prevention of the disease not only includes the usage of hig h-nux synthetic membranes for hemodialysis or hemodiafiltration, but that o ther factors contribute to the clinical manifestations of amyloidosis such as the dialysate composition and its microbacteriological quality. Such fac tors, which have changed over the last years as part of general improvement s in dialysis carl, may explain why the prevalence of the amyloidosis appea rs to decrease.