Serum hepcidin measured by immunochemical and mass-spectrometric methods and their correlation with iron status indicators in healthy children aged 0.5-3 y

BACKGROUND: The diagnostic use of hepcidin is limited by the absence of standardization and lack of age-specific reference ranges in children in particular. The aim of this study was to determine reference ranges of serum hepcidin in healthy children aged 0.5-3 y using mass spectometry (MS) and a commercial immunochemical (IC) assay, and to investigate its association with other indicators of iron status and inflammation. METHODS: We included 400 healthy children aged 0.5-3 y. We constructed reference ranges for MS-hepcidin and IC-hepcidin concentrations using the median, P2.5, and P97.5 in a normative population of 219 children with no anemia, no infection and/or inflammation, and no iron deficiency. RESULTS: Median concentrations (P2.5-P97.5) of MS-hepcidin and IC-hepcidin were 3.6 nmol/l (0.6-13.9 nmol/l) and 7.9 nmol/l (1.9-28.6 nmol/l), respectively. We found a good correlation between both methods. However, MS-hepcidin was consistently lower than IC-hepcidin. Hepcidin correlated with ferritin and C-reactive protein. CONCLUSION: We provide reference ranges for hepcidin for an MS and commercial IC method. Absolute values between assays differed significantly, but hepcidin concentrations obtained by MS and IC methods correlate with each other, and both correlate with ferritin and CRP.