Albertine Donker

Iron Function and Iron Handling from Fetus to Adult 57 2 In case of ID enhanced erythropoiesis and tissue hypoxia due to (especially iron deficiency) anemia, hepcidin production drops in order to ensure sufficient iron supply to the bone marrow for the production of erythrocytes. Treatment with erythropoiesis stimulating agents, chronic liver disease with impaired synthesis function of the liver and (supplementation of) the sex hormones testosterone and estrogen also cause a decrease of hepcidin production. 7,25 Conversely, iron excess and inflammation induce hepcidin production while impaired renal function results in decreased excretion, both leading to impaired iron uptake by the enterocytes and also to impaired iron release from the macrophages. 7,23,25 Restriction of iron availability in the serum by inducing hepcidin synthesis is part of the host defense because this mechanism limits the iron supply to extracellular iron-dependent pathogens. 24,26-28 The set point of serum hepcidin relative to indicators of body iron changes during childhood Measurement of hepcidin is a promising clinical tool in the diagnosis and management of both genetic (e.g. Iron Refractory Iron Deficiency Anemia (IRIDA) 29 ) and acquired iron disorders (iron deficiency, iron deficiency anemia, iron loading, iron maldistribution). 7 Determination of serum hepcidin levels might also help in predicting the response to oral iron therapy and in guiding iron treatment under conditions of competing signals (anemia, iron deficiency, inflammation), in combination with other iron and inflammation parameters. 30 Data on this application in childhood are limited. 31-33 Moreover, implementation of serum hepcidin levels in clinical pediatrics is hampered by the lack of standardized reference values of healthy children from different age groups, relative to iron status. 34-36 Available studies concern either small series with limited age groups or series including children with (anemia of) inflammation. 31,37-41 We therefore recently determined serum hepcidin values, hepcidin/ferritin rations and TSAT/hepcidin ratios in 266 Dutch children aged 0.3-17 year (www.hepcidinanalysis.com 42 ), 43 using a standardized assay. 44 Interestingly, we found that hepcidin levels are relatively high corrected for indicators of stored and circulating iron in children < 12 years compared to children > 12 years. Since especially young children are more susceptible to severe life threatening infections one might argue that relatively high hepcidin