LIVER-INJURY DUE TO IRON OVERLOAD IN THALASSEMIA - HISTOPATHOLOGIC AND ULTRASTRUCTURAL STUDIES

The livers of 30 cases of thalassemia (19/beta-thal/HbE, seven thal/Hb H and four beta-thal major) were studied histopathologically and elect ron microscopically, in an effort to define the morphologic alteration s due to iron overload. The results of light and electron microscopy w ere similar in most cases. Iron accumulation and fibrosis were the com mon features found in these patients, except that thal/HbH exhibited l esser hepatic damage. The degrees of iron deposition and fibrosis were found to be higher in splenectomized and cirrhotic than non-splenecto mized and non-cirrhotic patients. The subcellular changes were swollen mitochondria, with the presence of an electron dense matrix and ruptu red mitochondrial membrane. Proliferation of smooth endoplasmic reticu lum (ER) and dilated rough ER was observed. Increases in lysosomal hem osiderin in hepatocytes and in Kupffer cells were demonstrated. The po ssible ways by which the iron compounds or free radicals mediated memb rane damage are mentioned. The pattern of liver cell damage is similar to that of viral hepatitis.