Non-transferrin-bound iron (NTBI): an ignored lethal toxin

Iron overload disorders are common untreated a cause of severe systemic symptoms and organ damage to the liver, heart, brain, spleen, pancreas, gonads and generally in parenchymal tissue. After exceeding the iron binding capacity of the body, tocic free iron (non-transferrin bound iron = NTBI) can enter the circulation and from there into the cells. NTBI is only treatable by chelation therapy in emergency cases (e.g. after transfusions). In the long term, chelation therapies are risky, sometimes even life-threatening, in cases of NTBI overload. NTBI is formed in the body after the uptake of iron and very specifically from a transferrin saturation of 50% in women and towards 55% in men. From 60% to 70%, the total NTBI load increases exponentially. The lack of knowledge about NTBI still costs the lives of numerous people today. This is because it is neither directly measurable nor stainable in biopsies.