Discovery of the iron-regulatory hormone hepcidin in 2001 has revolutionized our understanding of iron disorders, and its measurement should advance diagnosis/treatment of these conditions. Although several assays have been developed, a gold standard is still lacking, and efforts toward harmonization are ongoing. Nevertheless, promising applications can be already glimpsed.
Promising applications in diagnostic medicine range from the use of hepcidin levels for diagnosis of iron-refractory iron deficiency anemia to global health applications such as guiding safe iron supplementation in developing countries with high infection burden.
Measuring hepcidin levels is also anticipated to be helpful both in selecting patients and monitoring the effects of novel hepcidin modulating therapies. This includes hepcidin agonists for treatment of iron overload disorders, and hepcidin antagonists for treatment of iron restriction in ACD.
Since hepcidin is a highly dynamic hormone, that is regulated by numerous factors, the correct interpretation of hepcidin levels in a given individual requires accurate knowledge of the overall clinical context.
Much is still unknown on how exactly hepcidin is regulated and most of the evidence on hepcidin regulation and mode of action comes from in vitro work and animal studies that often use hepcidin mRNA as a read out. Thus, although these discoveries on the regulation and mode of action of hepcidin have had wide reaching effects throughout the field, much work remains in defining the role of hepcidin in both healthy and diseased states in man. Furthermore, before hepcidin can be fully included in clinical practice and public health, further efforts must be undertaken to harmonize and standardize assay outcomes, to conduct large and well design studies to collect further evidence to firmly establish the position of hepcidin in diagnostic medicine, to define clinical decision limits, to make validated assays more available to clinical laboratories, and to assess its usefulness in clinical trials with hepcidin modulators for treating iron disorders.