Usefulness of random fecal alpha 1-antitrypsin and chymotrypsin determinations in children.

Random fecal chymotrypsin activity and fecal alpha 1-antitrypsin (FA-1-AT) concentrations were determined in 11 children with cystic fibrosis, 5 children with Crohn's disease, 9 children with chronic aspecific diarrhea, 85 children with acute gastroenteritis, and 54 control children. Cystic fibrosis patients showed only very low fecal chymotrypsin values that did not overlap with values obtained in patients with either acute or chronic diarrhea. When compared with our control group, a significant increase of FA-1-AT concentrations was found only in children with Crohn's disease. Normal values were found in all patients with either chronic aspecific diarrhea or cystic fibrosis, while 12 of 85 children with acute gastroenteritis showed FA-1-AT concentrations above the 95th percentile of control children. We conclude that diarrhea (either acute or chronic) does not significantly decrease the clinical usefulness of fecal chymotrypsin activity measurements in the diagnosis of pancreatic insufficiency, while acute (gastroenteritis) but not chronic (chronic aspecific diarrhea, cystic fibrosis) diarrhea can give rise to protein losing and FA-1-AT concentrations similar to those found in Crohn's disease.