Influence of Perinatal Factors on Blood Tryptase and Fecal Calprotectin Levels in Newborns

Blood tryptase and fecal calprotectin levels may serve as biomarkers of necrotizing enterocolitis. However, their interpretation may be hindered by the little-known effects of perinatal factors. The aim of this study was to compare the tryptase and calprotectin levels in newborns according to their term, trophicity, and sex.

One hundred and fifty-seven premature newborns and 157 full-term newborns were included. Blood tryptase and fecal calprotectin were assayed.

Blood tryptase levels were higher in premature than in full-term newborns (6.4 vs. 5.2 µg/L; p < 0.001). In situations of antenatal use of corticosteroids (p = 0.007) and non-exclusive use of human milk (p = 0.02), these levels were also higher. However, in multiple linear regression analyses, only prematurity significantly influenced tryptase levels. Fecal calprotectin levels were extremely wide-ranging and were much higher in female than in male newborns (300.5 vs. 110.5 µg/g; p < 0.001).

The differences in tryptase levels according to term could be linked to early aggression of the still-immature digestive wall in premature newborns, in particular, by enteral feeding started early. The unexpected influence of sex on fecal calprotectin levels remains unexplained.