Evaluation of faecal calprotectin as an early surrogate marker for necrotizing enterocolitis in preterm infants

Background/Objectives: Early prediction of necrotizing enterocolitis (NEC) has important implications for therapeutic strategies. Calprotectin is an abundant and extremely stable neutrophil protein in feces and reflects bowel inflammation in adults with chronic inflammatory bowel disease. Therefore, it may also serve as an surrogate marker for development of the NEC.

Aim: The aim of the study was to assess (1) the normal range of calprotectin concentrations during the first six weeks after birth, and (2) the validity of fecal calprotectin as a noninvasive marker for necrotizing enterocolitis in preterm infants.

Methods: In a prospective study, faecal samples were collected for analysis of calprotectin from 35 preterm infants (28,3±2,5 weeks gestational age) with less than 1500g birth weight (1022±308) daily for six weeks. Fecal calprotectin concentration was measured by an enzyme linked immunosorbent assay (ELISA).

Results: Using ANOVA analysis, the fecal calprotectin concentrations increased significantly in newborns without NEC with their age within the first six weeks (p<0,001). A detailled analysis revealed a significant increase of calprotectin levels from week two (98,4±12,6µg/ml) to week three (139,1±17,9µg/ml, p<0,002) and from week four (114,8±19,6µg/ml) to week six (188,3±23,7µg/ml, p<0,008), respectively. Calprotectin concentrations within the first two weeks were not significantly different.

Conclusion: The calprotectin concentration in feces is increases with age in preterm infants during the first weeks after birth. Thus, the normal range of calprotectin concentration should be age-adjusted. It may be a useful adjuvant for discriminating between newborns developing a NEC and other abdominal complications but higher patient numbers with NEC are needed.