Beta-2-microglobulin amyloidosis and renal bone disease.

Dialysis-related amyloidosis is a highly invalidating complication of chronic dialysis patients. Clinically and radiologically, the complication generally becomes manifest after more than 5-10 years of dialysis treatment. It is characterized by chronic arthralgias, periarticular soft-tissue swelling, carpal tunnel syndrome, diffuse destructive arthropathy and spondylarthropathy, lytic bone lesions, and sometimes pathologic fractures. Biochemically, amyloid deposits are mainly composed of beta-2-microglobulin fibrils together with the P component and glucose aminoglycans, the latter two being associated with all types of amyloidosis. The pathogenesis of the syndrome is still poorly understood. Recently, evidence has been provided for the possibility that beta-2-microglobulin is not a passive bystander, but an active player in the initiation and progression of the disease. The potential role of the dialysis technique, including the mode of dialysis and the biocompatibility of dialysis membrane used, is also under discussion.