Hepcidin as a biomarker for the diagnosis of iron metabolism disorders: a review.

Hepcidin plays a key role in the regulation of plasma iron levels through inhibition of iron export from enterocytes and macrophages. Hepcidin is considered a promising marker in the investigation of iron status, especially in patients that still pose a diagnostic challenge, such as infants and patients with chronic (kidney) disease.To critically review the current evidence for the diagnostic utility of hepcidin, including the (pre) analytical aspects in hepcidin determination.(Pre)analytical aspects--Since it is doubtful that the prohormone prohepcidin is a relevant biomarker, only the mature peptide hepcidin should be measured. Determinations of serum hepcidin are preferable, as the value of urine concentrations is still unclear. Method harmonization is needed since hepcidin values vary widely between methods. Several (pre-) analytical issues remain unanswered. These barriers hamper the investigation into the diagnostic value of hepcidin. Diagnostic utility--Hepcidin is an acute-phase reactant. The diagnostic potential of hepcidin is controversial in the different settings of iron deficiency as evidence is contradictory (anaemia of chronic disease) or limited (infants). In the setting of haemochromatosis, it has been suggested that hepcidin could be useful to stratify molecular testing, or to optimize the frequency of phlebotomies, but this remains to be investigated.