Enterokinase and trypsin activities in pancreatic insufficiency and diseases of the small intestine.

The interrelationship of enterokinase and trypsin activities were investigated in 133 infants and children with a variety of gastrointestinal and pancreatic disorders. Fourteen patients with diarrhea and grade II mucosal injury revealed a significant (P less than 0.01) reduction of enterokinase, trypsin, and disaccharidase activites as compared to 59 children with normal mucosa. Nine patients with cystic fibrosis and pancreatic insufficiency had normal mucosal enterokinase activity and elevated intraluminal enterokinase activity with very low or no trypsin activity. Patients with hypoproteinemia and gastrointestinal protein loss, associated with intestinal lymphangiectasia (4 patients) and intestinal lymphoid nodular hyperplasia (3 patients), had normal or insignificant decrease of enterokinase and trypsin activities. In patients with steatorrhea, a normal sweat test, normal intestinal mucosa, and absent trypsin activity, two entities were defined. One group (3 patients) was diagnosed as Schwachman-Diamond syndrome with pancreatic insufficiency and normal mucosal and intraluminal enterokinase activity. The second group (2 patients) with absent mucosal and intraluminal enterokinase activity and normal lipase and amylase activities was diagnosed as congenital enterokinase deficiency.