Does Iron Concentration in a Liver Needle Biopsy Accurately Reflect Hepatic Iron Burden in β-Thalassemia?

Abstract

β-Thalassemia major is an autosomal recessive disease characterized by absent or decreased synthesis of the β-globin gene (1). Thalassemic children, estimated at 100 000 worldwide, are affected by chronic anemia and need regular blood transfusion (2). Because of the limited capacity of iron excretion in humans, the iron in transfused red cells accumulates in the body. The liver, heart, and pancreas are the target organs of iron-induced injury; therefore, the major pathological manifestations observed in β-thalassemia major are chronic liver disease, evolving to cirrhosis, and dilative cardiomyopathy, both characterized by severe iron deposition (3)(4). The dangerous effects of iron excess can be managed by administration of chelators capable of removing iron from transferrin, ferritin, and other iron stores (5)(6)(7). Determination of the hepatic iron concentration (HIC) is one of the most valid procedures in assessing real body iron burden (8)(9)(10), which is important for adjusting each patient’s chelation therapy over the years. HIC usually is measured on one part of a needle biopsy core, and the measured value is considered representative of the iron concentration in the whole liver (11). In 1995, a study by our group (3) first showed that iron is unevenly distributed in the livers of β-thalassemic patients, and therefore, the iron content determined in a small liver fragment should be interpreted with caution because it cannot be considered a true representation of the mean HIC. These data were confirmed by us (12)(13)(14) and by other authors (15), who reported differences in HIC measurements on liver biopsy specimens. Recently, a striking difference in HIC was found in biopsy samples from cirrhotic livers (range, 60–2851 μg/g dry weight) (16). It therefore seemed of interest to measure iron concentrations in a large number of needle …