Citrulline concentration in routinely collected neonatal dried blood spots cannot be used to predict necrotising enterocolitis

AimLow citrulline concentration is a marker of low functional enterocyte mass, which may predispose neonates to necrotising enterocolitis (NEC). We hypothesised that citrulline could be used to assess the NEC risk that could not be accounted for by gestational age and birthweight. This study investigated whether citrulline concentrations routinely measured in neonatal dried blood spots (DBS) could predict NEC. MethodsWe used national Danish registries to retrospectively identify all 361 babies born between 2003 and 2009 who were diagnosed with NEC and had a valid citrulline concentration measured from a DBS sample. The control group comprised 1083 healthy newborns, with three controls for every newborn with NEC, matched for birthweight and gestational age. ResultsNeonatal dried blood spots were collected between 2 and 21days of life, with a median of 8days. The results showed that NEC was not associated with low citrulline concentration, either in a direct comparison between the NEC and control groups or in a multivariate logistic regression (p=0.73). ConclusionThe findings of this study show that the citrulline concentrations found in routine DBS samples between 2003 and 2009 did not predict NEC in newborn babies.