The compromised gut in the neonate: Diagnostic and clinical aspects

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease predominantly occurring in preterm infants, causing significant patient morbidity and mortality. It is characterized by loss of bowel wall integrity due to ischemia (lack of oxygen due to a compromised blood flow) and necrosis, but often starts with non-specific symptoms. Therefore, for diagnostic and prognostic purposes accurate biomarkers are needed that can timely predict the full expression of the disease.

Intestinal fatty acid-binding protein (I-FABP) is a small protein present in the small bowel wall and released into the blood stream upon cell disruption, after which it is readily excreted by the kidneys. I-FABP can therefore be measured in blood as well as in urine and seems to be a promising biomarker for NEC-induced intestinal damage.

Study results presented in this thesis show that I-FABP, whether measured in blood or urine, can identify neonates in whom non-specific symptoms will evolve into definitive NEC. This diagnostic ability of I-FABP was already present within eight hours after onset of − non-specific − symptoms. Moreover, results of serial I-FABP measurements prove to accurately predict development of complicated disease, defined as disease resulting in a surgical intervention and/or death. A strong correlation and agreement between I-FABP measured in blood and in urine offers the clinician all the advantages of urine measurements over blood sampling.

Future efforts should be aimed at using I-FABP as a point-of-care test to facilitate clinical decision-making in neonates with suspected and confirmed NEC.