Is cord blood hepcidin influenced by the low-grade acute-phase response occurring during delivery? A small-scale longitudinal study

Abstract

Aim: To measure serum hepcidin in late pregnancy and in cord blood, and to analyze relationship between hepcidin, interleukin-6, and biomarkers of fetal iron status.

Materials and methods: Data from 15 uncomplicated singleton pregnancies were analyzed longitudinally in trimester 3 (T3) and at birth.

Results: In T3, S-ferritin (median 14 µg/L) and transferrin (median 4.0 g/L) indicated low iron status, whereas the median soluble transferrin receptor (sTfR) was 4.0 mg/L, i.e. within the reference interval. Median T3 S-hepcidin was 7.8 ng/mL. Later on in cord blood, ferritin concentration (180 µg/L) were significantly higher, transferrin concentration (1.8 g/L) were significantly lower, and both sTfR (4.7 mg/L) and S-hepcidin concentrations (30.5 ng/mL) were significantly higher than maternal T3 concentrations. At the same time, cord blood interleukin-6 indicated an activated acute-phase reaction. In T3, after logarithmic transformation, there was a significant correlation between S-hepcidin and both S-ferritin (r = 0.691) and sTfR (r = -0.825). There was also a significant correlation between S-ferritin and both sTfR (r = -0.729) and transferrin (r = 0.549) in T3.

Conclusions: Although S-ferritin, S-hepcidin, and sTfR were correlated during pregnancy, these relationships were not apparent in umbilical cord blood. Further, cord blood interleukin-6 indicated an activated acute-phase response, and sTfR, which is known to be unaffected by inflammation, indicated a low iron status in cord blood. Thus, instead of representing an enhanced iron status, the data appear to suggest that hepcidin and ferritin in cord blood may be influenced by the low-grade acute-phase response that occurs during delivery.

Keywords: Iron; cord blood; ferritin; hepcidin; pregnancy.