Ferric iron (Fe3+) in labile iron pool and non-transferrin-bound iron (LIP/NTBI)

Ferric iron (Fe3+) within the labile iron pool (LIP) and non-transferrin-bound iron (NTBI) represents the chemically reactive, potentially toxic fraction of iron in biological systems. NTBI typically emerges in the plasma when the iron-carrying capacity of transferrin is saturated, often due to chronic blood transfusions or hereditary hemochromatosis (Breuer et al., 2000, Blood). The LIP is an intracellular counterpart consisting of loosely bound iron that is readily available for metabolic processes but also capable of participating in Fenton chemistry (Kakalou et al., 2004, Blood). These iron species catalyze the production of hydroxyl radicals, leading to systemic oxidative stress, lipid peroxidation, and organ damage, particularly in the liver, heart, and endocrine glands (Mobarra et al., 2016, Medical Science Monitor). Therapeutic management involves the use of iron chelators, such as deferoxamine, deferiprone, and deferasirox, which bind these iron ions to form stable complexes for excretion (Kontoghiorghes et al., 2004, Drugs). Monitoring NTBI and LIP levels is essential for assessing the risk of iron-mediated toxicity and the efficacy of chelation therapy in patients with iron overload disorders.

Other names

Labile iron poolNon-transferrin-bound ironLabile plasma ironLPIChelatable ironRedox-active iron

Chelation of ferric iron (Fe3+) to form stable, non-toxic complexes that are subsequently excreted via the kidneys or bile.