Osteoarticular amyloidosis associated with haemodialysis: an immunoultrastructural study.

Osteoarticular amyloidosis occurred in a patient receiving long term haemodialysis. Histological examination showed that the amyloid deposit was surrounded by inflammatory cells and macrophages filled with haemosiderin. Electron microscopy showed that the amyloid fibrils were in close contact with cytoplasmic expansions, or located in intracytoplasmic pockets of the infiltrating cells. Immunohistological and immunoultrastructural observations confirmed that beta 2-microglobulin was a major constituent of amyloidosis associated with dialysis. Amyloid P component was also detected within the amyloid deposits. These findings suggest that amyloid P component, iron overload, or macrophage derived factors could have a role in the polymerisation of beta 2-microglobulin into amyloid deposit.