Aims: To evaluate the clinical utility of two new tests for serum trypsinogen 2 and trypsin 2-alpha 1 antitrypsin complex (trypsin 2-AAT) in diagnosing and assessing the severity of acute pancreatitis (AP) induced by endoscopic retrograde cholangiopancreatography (ERCP).
Patients: Three hundred and eight consecutive patients undergoing ERCP at Helsinki University Central Hospital in 1994 and 1995.
Methods: Patients were followed prospectively for pancreatitis and clinical outcome. They were tested for serum trypsinogen 2, trypsin 2-AAT, and amylase in samples obtained before and one, six, and 24 hours after ERCP.
Results: Pancreatitis developed in 31 patients (10%). Their median serum trypsinogen 2 increased 26-fold to 1401 micrograms/l at six hours after the procedure and trypsin 2-AAT showed an 11-fold increase to 88 micrograms/l at 24 hours. The increase in both markers was stronger in severe than in mild pancreatitis, and in patients without pancreatitis there was no significant increase. Baseline trypsinogen 2 and trypsin 2-AAT concentrations were elevated in 29% and 32% of patients, respectively. The diagnostic accuracy of a threefold elevation over the baseline value was therefore analysed. The sensitivity and specificity of these parameters in the diagnosis of post-ERCP pancreatitis was 93% and 91%, respectively, for serum trypsinogen 2 at six hours after the examination, and 93% and 90%, for trypsin 2-AAT at 24 hours.
Conclusions: Serum trypsinogen 2 and trypsin 2-AAT reflect pancreatic injury after ERCP. High concentrations are associated with severe pancreatic damage. The delayed increase in trypsin 2-AAT compared with trypsinogen 2 appears to reflect the pathophysiology of AP. A greater than threefold increase in trypsinogen 2 six hours after ERCP is an accurate indicator of pancreatitis.