[Disaccharidase activity as a diagnostic criterion for the mucosa of the small intestine].

Activities of lactase, sucrase, and maltase were determined in small intestinal biopsies of 125 children with coeliac disease, cow's milk protein intolerance, transient gluten intolerance, nonspecific enteropathies, and controls. Four cases of primary disaccharidase deficiencies could be identified. In the enteropathies, morphometric data were more closely correlated to the degree of the mucosal lesion (r = -0.92 for crypt depth) than were disaccharidase activities (r = 0.61 for lactase). In a stepwise discriminant analysis of the patient groups, based upon immunological, morphometric, and biochemical variables, lactase activity was a valuable secondary criterion, ranking third among the variables used.