Evaluation and comparison of cathodic trypsin-like immunoreactivity, pancreatic lipase and pancreatic isoamylase in the diagnosis of acute pancreatitis in 849 consecutive patients with acute abdominal pain.

In 849 patients (417 men, 432 women) consecutively hospitalized with acute abdominal pain we compared the value of serum cathodic trypsin-like immunoreactivity, pancreatic lipase (EC 3.2.1.3) and pancreatic isoamylase (EC 3.2.1.1) as diagnostic tests for acute pancreatitis. The diagnoses of acute pancreatitis (in 49 patients, 5.8%) and other diseases were made without knowledge of these enzyme values. When evaluated by means of receiver operating characteristic curves no differences were found in diagnostic performance of the three enzymes. Use of combinations of different enzymes had no advantage over single enzyme determination using discrimination analysis for evaluation. The highest efficiency was for all three enzymes 0.991 (95% confidence limits: 0.983-0.995) and for all three enzymes the discrimination value giving this efficiency was several times the upper limit of reference range: 1 779 micrograms/l for cathodic trypsin-like immunoreactivity, 831 U/l for pancreatic isoamylase and 316 micrograms/l for pancreatic lipase. None of the enzymes had any prognostic value at admission in predicting a mild or severe attack of acute pancreatitis. In conclusion, no single enzyme or combination of enzymes had any diagnostic advantage for acute pancreatitis in patients with acute abdominal pain. Thus selection of one of the three enzymes as diagnostic test of acute pancreatitis is to be based on considerations such as economy, methodological simplicity, possibility of automated assay and the time-consumption at the assay.