Fecal clearance of α 1-antitrypsin: A reliable measure of enteric protein loss in children

Abstract

MEASUREMENT of fecal clearance of a,-AT has been proposed as a technique for assessing enteric protein loss, but clinical evaluations of the method have yielded conflicting results? :~ Since the technique is simple and does not require radioactive isotopes, it could have advantages over conventional, somewhat laborious radionuclide procedures used for this purpose. A valid, safe and simple technique to measure enteric protein toss would be a decided asset in the diagnosis and continuing evaluation of children with disorders causing proteinlosing enteropathies. We measured fecal a,-AT clearance in a group of children and compared our results with data on enteric protein loss obtained using a conventional radionuclide procedure in the same patients. PATIENTS AND METHODS During a 12-month period, we studied 15 children ranging in age from 4 months to 18 years. In each case, the findings had suggested the diagnosis of a protein-losing enteropathy and led to a request that the patient undergo a standard ~'CrCt:, protein-labeling test for enteric protein loss. In the study there were ten children with inflammatory bowel disease; five with Crohn disease involving ileum and colon, one with Crohn disease of the small bowel only, two with eosinophilic gastr0enteritis of the small bowel, and one with ulcerative colitis. Inflammatory involvement of the colon caused heavy blood staining of the stools in two of these patients. The remainder of the study group was composed of single cases of intestinal lymphangiectasia, constrictive pericarditis, soy protein intolerance, colonic polyposis, congenital biliary dysplasia, and one child who was malnourished because of psychosocial deprivation. When appropriate, diagnostic investigations included barium contrast roentgenograms of the upper and lower bowel, endoscopy, and suction biopsies of the duodenal or rectal mucosa. Liver function studies were normal in all but the one child with congen