Ultrastructural Features of Sidero - apoptotic Hepatocytes in Thalassemia

Liver tissues from 20 patients with thalassemia were investigated by light and electron microscopy, with focus on ultrastructure of sidero-apoptosis. The results of light microscopy were compared. Sidero-apoptosis was found in 82% in β thal/Hb E disease, 67% in thalassemia Hb H, 100% in and β-thal major, respectively. Regardless of the type of hemoglobin, sidero-apoptosis was present in various degrees. The main criteria used for identification of sidero-apoptosis were marked condensation of chromatin against the nuclear membrane, and fragmentation into nuclear fragments of varying sizes and structures into membrane-bounded sidero-apoptotic bodies. These bodies may be phagocytosed by macrophages or neighboring cells or remain free. However, the cell may also shrink into a dense, rounded mass, as a single sidero-apoptotic body. Sidero-apoptoic bodies were similar to acidophilic bodies, or Councilman bodies, commonly found in viral hepatitis. This preliminary report suggested that sidero-apoptosis is a features of human liver pathology in thalassemia and may be due to hepatotoxicity of iron overload. In addition, many factors or other agents-hormone, killer cells, cytokines, various physical, chemical and viral agents should be considered. We propose the term "sidero-apoptosis" to describe the features resembling acidophilic bodies commonly seen in viral hepatitis but with a heavy deposit of iron.