[Physiopathology of iron metabolism and hemochromatosis: interrelationships, assessment and pathogenesis of iron overload, screening].
Fundamental aspects of iron metabolism relate to the dynamic processes of metal plasma transport as well as cell storage and efflux. Transferrin not only carries iron in the plasma but also delivers it to the various cells by binding to a diffuse specific cell receptor; it also acts by chelating cell iron. Ferritin co-operates by storing iron in the cell. By a still unknown regulatory mechanism, iron, from the ferritin pool, is redistributed in the cell to a cytosolic, easily chelatable, "transit" pool or to a degradative lysosomal hemosiderin pool from which it is slowly released outside the cell. Iron overload, such as that typical of hyperhemolysis or hemochromatosis, profoundly impairs its metabolism by saturating and/or altering transferrin and ferritin, by freeing iron from any regulated transport, thus allowing parenchymal deposition and damage. An important aspect still awaiting clarification relates to the different storage of excess iron in the parenchymal cells, as in hemochromatosis, or in the reticuloendothelial system such as in hemosiderosis. Studies using cellular models attempt to evaluate such differences in terms of altered properties of the iron proteins or their cell receptors, and of the different cell responsivity to non-transferrin iron. In the expectation of better knowledge, attention should be concentrated, from a clinical standpoint, on precise assessment of iron deposits in the tissues with the aim of preventing its excessive accumulation and parenchymal damage. In hemochromatosis, the risk of iron overload is evaluated by HLA typing.
Carrella
M
M
Del Piano
C
C
D006680:HLA Antigens; D006432:Hemochromatosis / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D007501:Iron / Q000378:metabolism*
D006680:HLA Antigens; D007501:Iron
Fisiopatologia del metabolismo del ferro ed emocromatosi: interrelazioni, inquadramento e patogenesi del sovraccarico di ferro, screening.