It doesn’t look like calprotectin measurement in newborns is going to be terribly useful for detecting necrotizing enterocolitis.  A recent study (W Nakayuenyongsuk et al. J Pediatr 2018; 196: 98-103) showed a great deal of variability in the calprotectin values in their cohort of 62 infants.

Methods:

• All infants had a birth weight of <1500 g
• Stools collected daily (first stool of the day) either for 30 days or postmenstrual age of 32 weeks (whichever was longer)

Results: Calprotectin Values in microgram/gram

• 1st week of life: All patients: Mean 637 +/- 638, Median 273
• 2nd week of life: All patients: Mean 349 +/- 414, Median 180
• 3rd week of life: All patients: Mean 486 +/- 470, Median 316
• 4th week of life: All patients: Mean 488 +/- 385, Median 412
• 5th week of life: All patients: Mean 358 +/- 339, Median 226
• 6th week of life: All patients: Mean 370 +/- 334, Median 295
• 7th week of life: All patients: Mean 240 +/- 191, Median 184
• 8th week of life: All patients: Mean 445 +/- 110, Median 466

The highest subset scores for calprotectin was noted in the 1st week of life among preterm infants with gestational age >30 weeks.  In this group, the mean value was 799 +/- 651 and the median value was 718.

There were only two patients who developed necrotizing enterocolitis, both of whom did have an early rise in calprotectin

My take: This data shows elevated and highly variable calprotectin values in the neonatal period.  There was also a trend towards higher values among those with postnatal age >30 weeks.

Related blog post: Fecal calprotectin values in first years of life