Association of cord blood digitalis-like factor and necrotizing enterocolitis

Abstract

Objective: Endogenous digoxin-like factor (EDLF) has been linked to vasoconstriction, altered membrane transport, and apoptosis. Our objective was to determine whether increased EDLF in the cord sera of preterm infants was associated with an increased incidence of necrotizing enterocolitis (NEC).

Study design: Cord sera from pregnant women enrolled in a randomized trial of MgSO4 for fetal neuroprotection were analyzed for EDLF using a red cell Rb(+) uptake assay in which the inhibition of sodium pump-mediated Rb(+) transport was used as a functional assay of EDLF. Specimens were assayed blinded to neonatal outcome. Cases (NEC, n = 25) and controls (neonates not developing stage 2 or 3 NEC, n = 24) were matched by study center and gestational age. None of the women had preeclampsia. Cases and controls were compared using the Wilcoxon test for continuous and the Fisher exact test for categorical variables. A conditional logistic regression analysis was used to assess the odds of case vs control by EDLF level.

Results: Cases and controls were not significantly different for gestational age, race, maternal steroid use, premature rupture of membranes, or MgSO4 treatment. In logistic models adjusted for treatment group, race, premature rupture of membranes, and gestational age, cord sera EDLF was significantly associated with development of NEC (P = .023).

Conclusion: These data demonstrated an association between cord sera EDLF and NEC.

Keywords: cord blood; digitalis-like factor; necrotizing enterocolitis; pregnancy; sodium pump.

Figure 1

Box plot of EDLF level versus clinical status. The cord serum levels of EDLF were plotted as a function of disease group, showing neonates used as controls (no BPD, NEC or IVH) and those developing stage 2 or 3 necrotizing enterocolitis (NEC). The “+” symbolizes the mean.