Hepatic iron overload in renal transplant recipients: ultrastructural observations

This study describes the ultrastructural features of hemosiderosis occurring in five transplant recipients. Iron deposits in the form of homogeneous and heterogeneous siderosomes (iron-laden lysosomes) were found within the hepatocytes and macrophages in areas of fibrosis, and to a lesser degree within Kupffer cells and bile duct epithelium. Disruption of siderosomal membranes with extrusion of ferritin particles into the cytosol was demonstrated in these specimens and may be significant in the pathogenesis of hepatocellular injury.