Beta 2-microglobulin amyloidosis: a sternoclavicular joint biopsy study in hemodialysis patients

The incidence of beta 2-microglobulin deposits appears to increase with time on dialysis. However, the precise prevalence of the disease is not known at present because adequate, noninvasive diagnostic procedures are still lacking. We performed systematic synovial biopsies of the sternoclavicular joint during surgical parathyroidectomy in 22 chronic hemodialysis patients with severe hyperparathyroidism. Nine of the patients proved to have beta 2-microglobulin amyloid deposits as demonstrated by Congo red staining and by immunofluorescence. They had undergone dialysis for longer time periods (12.6 vs 8.5 years, p less than 0.02) and tended to be older than the 13 amyloid-negative patients. They also had a significantly higher body aluminum overload, as demonstrated by a higher increase of plasma aluminum after desferrioxamine infusion. Finally, the presence of Congo-red-positive deposits correlated well with clinical and x-ray findings suggestive of dialysis amyloidosis.