Hepcidin concentrations in serum and urine correlate with iron homeostasis in preterm infants.

OBJECTIVES: To evaluate whether hepcidin concentrations in serum (Hep((S))) and urine (Hep((U))) correlate with iron metabolism, erythropoiesis, and inflammation in preterm infants. STUDY DESIGN: Thirty-one preterm infants (23-32 weeks gestational age) were included. The concentration of the mature, 25 amino-acid form of hepcidin was determined by enzyme-linked immunosorbent assay in serum, urine, blood counts, reticulocytes, and iron measurements. RESULTS: Median (IQR) Hep((S)) was 52.4 (27.9-91.9) ng/mL. The highest values were measured in patients with systemic inflammation. Hep((S)) and Hep((U)) correlated strongly (P = .0007). Hep((S)) and Hep((U)) also correlated positively with ferritin (P = .005 and P = .0002) and with reticulocyte hemoglobin content (P = .015 and P = .015). Hep((S)) and Hep((U)) correlated negatively with soluble transferrin receptor/ferritin-ratio (P = .005 and P = .003). Infants with lower hemoglobin concentrations and higher reticulocyte counts had lower Hep((S)) (P = .0016 and P = .0089). CONCLUSION: In sick preterm infants, iron status, erythropoiesis, anemia, and inflammation correlated with the mature 25 amino-acid form of hepcidin. Further evaluation of Hep((U)) for non-invasive monitoring of iron status in preterm infants appears justified.