Hepcidin-25: Measurement by LC-MS/MS in serum and urine, reference ranges and urinary fractional excretion

The LC-MS/MS method was validated using a recent validation strategy based on accuracy profiles. Good results were obtained in terms of trueness, precision, and linearity in the following dosing ranges: from 0.77 to 200 nmol/L for urine and from 0.48 to 100 nmol/L for serum. The 95% reference range of serum hepcidin-25 concentration established after excluding known conditions that affect hepcidin-25 expression was 1.5 to 15.2 nmol/L. A difference between genders was demonstrated with a median concentration of 5.5 versus 7.2 nmol/L for women and men, respectively. Serum hepcidin-25 concentrations were strongly correlated with ferritin and, to a lesser extent, with iron levels. The coefficient of renal excretion ranged from 0.1 to 16.4%. Higher values of hepcidin-25 concentrations were observed on ethylene diamine tetraacetate tubes compared to serum or lithium-heparin devices.