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. 