[Amyloidosis in hemodialysis patients]

Amyloidosis in long-term haemodialysis patients mainly involves the osteo-articular system. It is held responsible for carpal tunnel syndrome, chronic arthralgia and various types of arthropathy, chronic synovitis and tenosynovitis, haemarthrosis, subacute polyarthritis and destructive arthropathies of the limbs and spine. Radiologically, amyloidosis may appear as bone cavities, particularly visible in the hips and wrists. Its frequency increases with the duration of haemodialysis. Biochemically, amyloidosis consists of beta 2-microglobulin (beta 2-M). This protein accumulates in uraemic patients under dialysis and seems to play a major role in the pathogenesis of amyloid deposits. The accumulation is due to renal impairment, being maximum in anuric patients. However, the unsatisfactory clearance of beta 2-M by dialysis methods also contributes to its retention: the production and elimination of beta 2-M seems to vary according to the extrarenal clearing technique. These data suggest that improvements in clearing techniques will eventually prevent dialysis amyloidosis.