Iron-mediated tissue damage in acquired ineffective erythropoiesis disease: It's more a matter of burden or more of exposure to toxic iron form?

Iron is essential in cellular life, however, when in excess, it favors the production of reactive oxygen species (ROS) that, when overwhelm the physiological cellular antioxidant system, produce an oxidative stress state leading to cellular damages and organ failure. What is not yet completely clear is whether the damage is related more to the amount of iron or to the duration of exposure to ROS. Various cellular pathways are sensitive to the detrimental action of ROS in a non-dose-dependent manner. In addition, different organs have a different capacity to respond to iron-mediated toxicity, suggesting that the toxicity thresholds are disease-specific and patient-dependent. The aim of this article is to review the recent understanding of the concept of exposure to free iron-mediated damage, comprehending the need to design protocols in which reducing organ exposure to ROS is the primary objective in order to prevent or delay the development of organ damage.