Faecal elastase 1 levels in premature and full term infants.
BACKGROUND
Determination of faecal elastase 1 (FE1) is a simple, relatively inexpensive, non-invasive, highly specific and sensitive test for determining pancreatic function. Secretion of pancreatic enzymes varies during infancy, but there are almost no specific data on the ontogeny of elastase 1 in human babies.


OBJECTIVE
To study FE1 levels in preterm and term babies, and to determine the possible effect of gestational and postconceptual age on these levels.


METHODS
Serial stool samples were collected and tested for FE1 level from 77 premature and full term infants. FE1 levels were determined by a commercially available enzyme linked immunosorbent assay (ELISA) kit.


RESULTS
A total of 232 stool samples were collected from 77 neonates. The FE1 level measured in the first stool sample (meconium) was below normal (200 micro g/g stool) in all samples regardless of gestational age. Sixty three neonates had at least two samples tested for FE1 level. The mean (SD) level of FE1 in sample 1 was 45.9 (51.1) micro g/g stool and was significantly (p < 0.001) lower than in sample 2 (243.0 (164.9) micro g/g stool). The lower the gestational age of the newborn, the more time it took for FE1 to reach normal levels.


CONCLUSIONS
FE1 levels in meconium are low, and studies in meconium should be avoided if pancreatic sufficiency is to be determined. FE1 reaches normal levels by day 3 in term newborns and by 2 weeks in infants born before 28 weeks gestation. Normal levels are reached sooner in infants of more advanced gestational age who start enteral feeding earlier.
Kori
M
M
Institute of Pediatric Gastroenterology and Nutrition, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.
Maayan-Metzger
A
A
Shamir
R
R
Sirota
L
L
Dinari
G
G
D000375:Aging / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000201:enzymology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D008297:Male; D008470:Meconium / Q000201:enzymology; D010196:Pancreatic Elastase / Q000032:analysis*; D010186:Pancreatic Function Tests / Q000379:methods; D012016:Reference Values; D012680:Sensitivity and Specificity
D015415:Biomarkers; D010196:Pancreatic Elastase