Early Detection of Impending Necrotizing Enterocolitis with Urinary Intestinal Fatty Acid-Binding Protein

<b><i>Background:</i></b> Necrotizing enterocolitis (NEC) is diagnosed after the development of feeding intolerance and characteristic physical and imaging findings. Earlier detection of a subclinical prodrome might allow for the institution of measures that could prevent or attenuate the severity of the disease. <b><i>Objectives:</i></b> We sought to determine whether urinary intestinal fatty acid-binding protein (iFABP_u) might be elevated prior to the first clinical manifestations of NEC. <b><i>Methods:</i></b> Urine was collected daily from 62 infants of a gestational age of 24-28 weeks. Based on clinical, imaging and operative findings, subjects were determined to have Bell stage 2 or 3 NEC. In all the subjects with NEC and in 21 age-matched controls, iFABP_u was determined using an ELISA, and was expressed in terms of its ratio to urinary creatinine (Cr), i.e. iFABP_u/Cr_u. Receiver operating characteristic (ROC) curves were constructed to define the predictive value of iFABP_u/Cr_u for impending NEC in the days prior to the first clinical manifestations. <b><i>Results:</i></b> Five subjects developed NEC (stage 2: n = 3 and stage 3: n = 2). The day before the first clinical manifestation of NEC, a ROC curve showed that an iFABP_u/Cr_u >10.2 pg/nmol predicted impending NEC with a sensitivity of 100% and a specificity of 95.6%. iFABP_u/Cr_u did not predict NEC 2 days prior to the first sign of disease. <b><i>Conclusions:</i></b> An elevated iFABP_u was a sensitive and specific predictor of impending NEC 1 day prior to the first clinical manifestations. iFABP_u screening might identify infants at a high risk and allow for the institution of measures that could ameliorate or prevent NEC.