A new test is presented for the evaluation of pancreas function in chi
ldren by determining fecal pancreatic elastase (elastase). Methods: El
astase was measured by an ELISA based on two monoclonal antibodies of
IgG2b class which specifically recognize two different epitopes of Fl.
A stool sample of about 0.5 g is sufficient for the test. Stool analy
sis was performed in 376 hospitalized infants and children, aged from
1 day to 14 years, without pancreas insufficiency, and 112 patients wi
th cystic fibrosis (CF), 7 days to 35 years of age. In 10 children ela
stase was measured in ten consecutively assembled stool samples to det
ermine intraindividual variability of elastase. In addition to descrip
tive analysis, Mann Whitney rank sum test was applied to compare elast
ase values of various age groups. Results: Fecal elastase values in th
e meconium of healthy newborn infants were between 5 and 195 ((x) over
bar = 64) mu g/g, independently of gestational age or physical develo
pment. In older infants and children values ranged between 168-4420 ((
x) over bar = 763) mu g/g, showing no statistical differences between
age groups, meconium values excepted, although there was a slight tend
ency of elastase concentrations increasing with age. Mean intraindivid
ual coefficient of variation was 15 (3 to 28) %. Of 112 CF-patients 95
had pathologically low values (< 150 mu g/g). In one CF-patient the p
ancreas function worsened within a few months as documented by decreas
ing fecal elastase concentrations. Conclusions: Determination of fecal
pancreatic elastase in a tiny sample is an additional tool to confirm
maturation or decrease of pancreatic function. The test impresses by
its simplicity, stability, and low variability.