Nontransferrin bound iron

The bleomycin assay has been applied to assess the levels of available, nontransferrin-bound iron in plasma samples in patients with iron overload disease (Peters et al., 1985), with acute leukaemia before and after drug chemotherapy (Halliwell et al., 1988), as well as patients with rheumatoid arthritis (Winyard et al., 1987). 

Parkes and co-workers have also conducted H NMR studies on s5movial fluid from patients with rheumatoid arthritis. Tbe nature of the nontransferrin-bound iron in the synovial fluid of patients with inflammatory joint disease was investigated. Transferrin is an iron ion transport protein. In these patients the synovial fluid contains non-transferrin-bound iron which appears to be in low-molecular-mass, redox-active complexes of unknown type. This form of iron has the adverse effect of stimulating free-radical lipid peroxidations involving oxygen. 500 MHz spin-echo H NMR spectroscopy was used to show that the incubation of patient synovial fluid with the powerful Fe(III)... 

Grootveld M, Bell JD, Halliwell B, Aruoma OI, Bomford A, Sadler PJ (1989) Nontransferrin-bound iron in plasma or serum from patients with idiopathic hemochromatosis. Characterization by high performance liquid chromatography and nuclear magnetic resonance spectroscopy. J Biol Chem 264 4417-4422 Gyparaki M, Porter JB, Huehns ER, Hider RC (1986) Evaluation in vivo of hydro-xypyrid-4-one iron chelators intended for the treatment of iron overload by the oral route. Biochem Soc Trans 14 1181-1181 Hallaway PE, Eaton JW, Panter SS, Hedlund BE (1989) Modulation of deferoxamine toxicity and clearance by covalent attachment to biocompatible polymers. Proc Natl Acad Sci USA 86 10108-10112... 

Oxidative stress and inflammation are elevated in hemodialysis patients, which, at least partly, might be initiated by intravenous iron administration. Thus, Tovbin et al. [377] showed that the administration of iron saccharide to hemodialysis patients increased the blood level of oxidized proteins. Similarly, an increase in the levels of free ( nontransferrin-bound or labile ) iron has been shown in the plasma of hemodialysis patients [378] including patients after intravenous iron saccharate infusion [379]. 

Without a mechanism for its excretion, iron accumulates in vital organs (Pietrangelo, 2002). Because the liver binds both circulating nontransferrin and transferrin-bound iron, the liver is at particular risk for iron overload. Excess iron causes damage to hepatocytes primarily through induction of oxidative stress (Parkilla et al., 2001). 

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