Reticuloendothelial
iron overload is associated with secondary
hemochromatosis including repeated transfusions and
iron over-supplementation.
Ferroportin disease B is a severe subtype of hereditary
iron overload syndrome with an activated reticuloendothelial system. The
iron exporter
ferroportin may be insensitive to
hepcidin 25 in this subtype. However, the interactions between the
hepcidin-
ferroportin system and modifiers of reticuloendothelial
iron overload have not yet been elucidated. We describe two patients with
iron overload conditions that were compatible with
ferroportin disease B, but their genetic backgrounds and habitual states differed. Both patients had diabetes, periportal
fibrosis with severe
iron deposits in their hepatocytes and Kupffer cells, and adequate levels of circulating
hepcidin 25. However, the first patient was heterozygous for a mutation in the FP gene and free from the acquired factors of
iron overload, while the second patient was a heavy drinker with a heterozygous mutation in the TFR2 gene and no mutations in the FP gene. The first patient was the second reported case of
ferroportin disease B in Japan. Our study on these 2 patients suggests that
liver fibrosis associated with compound
iron overload of reticuloendothelial cells and hepatocytes may occur via multi-etiological backgrounds.