Polyclonal pancreatic elastase assay is superior to monoclonal assay for diagnosis of acute pancreatitis.

We compared the clinical values for diagnosis of acute pancreatitis of two commercial assays for pancreatic elastase: an ELISA procedure with monoclonal antibodies and a RIA technique with polyclonal antibodies. In 14 patients with acute pancreatitis, serum concentrations of elastase determined by ELISA (ELISA-elastase) decreased much faster (half-life 0.4 days) than those of elastase determined by RIA (RIA-elastase) (2.2 days), amylase (0.8 days), or lipase (0.9 days). Serum samples from 253 additional patients with abdominal pain (32 of these with acute pancreatitis) were analyzed. In sera collected up to 48 h after the onset of disease, the ROC curves showed a slightly higher diagnostic value of RIA-elastase. In samples taken later, at a sensitivity of 90% the specificity of RIA-elastase was 95% (ELISA-elastase 40%). We conclude that serum ELISA-elastase is of much lower clinical value than RIA-elastase for diagnosis of acute pancreatitis.