Immunoreactive serum trypsin in diseases of the pancreas.

Immunoreactive serum trypsin was measured with a double antibody radioimmunoassay in normal 
subjects and patients with various diseases of the pancreas. The normal 
range is 115-350 ng/ml with a geometric mean of 212 ng/ml. 
No trypsin was found in serum after total duodenopancreatectomy, in about 
75% of patients with cystic fibrosis and in a few patients 
with pancreas carcinoma or chronic pancreatitis. Reduced serum trypsin levels between 
10 and 100 ng/ml were measured in the remaining 25% of 
cystic fibrosis and in one third of the patients with chronic 
pancreatitis. Serum trypsin was increased to 700-17,000 ng/ml in all patients 
with acute pancreatitis or during the acute phase of chronic pancreatitis. 
Absent or reduced serum trypsin is a reliable indicator of total 
or partial exocrine pancreatic insufficiency whereas considerably increased serum trypsin concentration 
do indicate acute pancreatitis. 