Cathodal elastase in duodenal juice from children with gastrointestinal disorders.

Immunoreactive cathodal elastase, elastinolytic activity, and activity on the low-molecular elastase substrate succinyl-trialanine were assayed in duodenal juice from 89 fasting children with different malabsorption problems. Cathodal elastase immunoactivity (mean value, 0.06 g/liter) averaged 1% of the total protein content in duodenal juice and 1/16 of the succinyl-trialanine-splitting activity. A strong influence of age was found for immunoactivity and elastinolytic activity, indicating continuing development of the cathodal elastase during the first 24 months of life. In 81 children with normal pancreatic function, significantly lower levels for all parameters including total protein were found for 14 with coeliac disease than for 34 children with unclassified gastrointestinal disorders and 33 with cow's milk protein intolerance. In eight children with pancreatic insufficiency, seven lacked detectable immunoactive cathodal elastase; low levels of succinyl-trialanine-splitting activity were found in six, and remnants of elastinolytic activity in three.