Novel approaches to quantitation and speciation of plasma non-transferrin bound iron: implications for prevention of iron mediated toxicity. (360G-Wellcome-093209_Z_10_Z)

In iron overload, the distribution to tissues at risk of iron toxicity is mediated though plasma species collectively referred to as non-transferrin bound iron (NTBI) but its nature has thus far been poorly characterised. The research will apply two novel analytical methods for the quantification and speciation plasma NTBI, developed by the principle applicant, to address key unresolved clinically relevant questions. NTBI speciation will be compared in iron overload conditions with different e xtra-hepatic iron distribution profiles, in particular with different iron loading to the myocardium. The relative effects on NTBI speciation of the currently used iron chelation (desferrioxamine, deferiprone, deferasirox) will be observed. The uptake of plasma NTBI species from plasma samples of patients into target tissues using hepatocyte and cardiomyocyte cell lines will be investigated by measuring intracellular iron fluxes fluorimetrically. The relative propensity of albumin bound and c itrate-coordinated NTBI species to uptake into these tissues will be determined, as well as the effects of clinically used chelators on this process. We hypothesise that albumin bound NTBI species will be more difficult to remove using chelation therapy than iron:citrate species. We further hypothesise that clearance of albumin bound NTBI species will occur more in hepatocytes than in myocardial cells.