Duodenal expression of a putative stimulator of Fe transport and transferrin receptor in anemia and hemochromatosis

Background: Stimulator of Fe Transport (SFT) and transferrin receptor (TfR) are proteins involved in iron transport. This study evaluated iron metabol ism protein expression in duodenal biopsy specimens from controls and patie nts with abnormal iron metabolism. Methods: Twelve controls, 8 patients wit h iron deficiency anemia, 7 with HFE-related hemochromatosis, and 6 with no n-HFE-related iron overload were studied. immunohistochemistry was performe d on duodenal biopsy specimens with anti-TfR and anti-SFT antibodies which recognize a putative stimulator of Fe transport of similar to 80 kilodalton s, Results: In controls, the putative stimulator of Fe transport was expres sed in the middle and distal part of the villi in the subapical cytoplasmat ic region. Its expression increased in anemics and, to a lesser degree, in HFE-related hemochromatotics, whereas it was reduced in patients with non-H FE-related iron overload, TfR expression showed a crypt-to-tip gradient in controls, but not in anemics, in whom it was uniformly overexpressed. TfR e xpression was intermediate in HFE-related hemochromatotics and similar to c ontrols in non-HFE-related iron overload. Conclusions: Expression of the pu tative stimulator of Fe transport and TfR increases in iron deficiency, Inc reased expression of both proteins is present only in HFE-related hemochrom atotics suggesting that other factors may be involved in determining non-HF E-related iron overload phenotype.