Serum cathodic trypsin-like immunoreactivity, pancreatic lipase, and pancreatic isoamylase as diagnostic tests of chronic pancreatitis or pancreatic steatorrhea.

We compared serum concentrations of cathodic trypsin-like immunoreactivity, pancreatic lipase, and pancreatic isoamylase as diagnostic tests of chronic pancreatitis (and of pancreatic steatorrhea in the 41 patients with steatorrhea) in 105 patients (57 men, 48 women) consecutively investigated because of clinical suspicion of chronic pancreatitis. Chronic pancreatitis (36 patients), pancreatic steatorrhea (24 patients), and other diseases were diagnosed without knowledge of the serum levels of the three enzymes. When evaluated by means of receiver operating characteristic curves, no differences were found in diagnostic performance of the enzymes with regard to chronic pancreatitis or pancreatic steatorrhea. The sensitivity and specificity for recognition of chronic pancreatitis ranged from 0.306 to 0.444 and from 0.942 to 0.986 when the discrimination values were chosen to give highest efficiencies. The similar ranges for pancreatic steatorrhea were 0.500-0.708 and 0.882-0.941. In conclusion, none of the three enzymes had any advantage over the others as diagnostic tests of chronic pancreatitis or of pancreatic steatorrhea. Only positive test results have clinical importance because of the low sensitivities of the three enzymes.