beta 2-microglobulin amyloidosis

beta 2-microglobulin amyloidosis is a new type of amyloidosis mainly observed in dialysis patients, whose frequency increases with the elapsed time of dialysis treatment. Its high incidence and its disabling characteristics bring it to the front among the complications observed in chronic renal failure patients. The pathophysiology of beta 2-microglobulin amyloidosis is not known. However, great progress has been achieved with recent work identifying a variety of substances that are contained in amyloid deposits and which have known metabolic activities likely to participate in amyloid fibril formation. Among them, three deserve special mention: (i) the advanced glycation end products (particularly the AGEP-beta 2-microglobulin), which result from the non-enzymatic glycation of proteins, known to be altered in chronic renal failure; (ii) the reactive oxygen species (ROS) which are released by the cells related to the amyloid deposits (macrophages and endothelial cells) and may participate in tissue damage and fibril precipitation; and (iii) alpha 2-macroglobulin, amyloid P component and other anti-proteases which modify the processing of amyloid fibrils and may also interact with macrophages and enhance amyloid fibril formation. Unfortunately, there is no treatment curing or preventing beta 2-microglobulin amyloidosis that we can presently offer to dialysis patients. The use of high flux membranes seems to delay its appearance and there is agreement in that renal transplantation clearly stops progression of this type of amyloidosis.