Accuracy of plasma levels of polymorphonuclear elastase as early prognostic marker of acute pancreatitis in routine clinical conditions

Abstract

Objectives: The early prognostic evaluation of acute pancreatitis (AP) is a key step in the appropriate management of the disease. Plasma levels of polymorphonuclear elastase have proved to be an accurate early prognostic marker of AP in research conditions. Whether the test remains sufficiently accurate in routine clinical conditions has been questioned. The aim of our study was to evaluate the accuracy of plasma polymorphonuclear-elastase levels for the early prognostic evaluation of AP in the clinical setting.

Methods: A total of 224 consecutive patients with AP admitted to our Gastroenterology Department were included. A blood sample for polymorphonuclear-elastase quantification was obtained from all of them in the first morning of hospital stay, together with samples for routine haematological and biochemical analysis. Blood samples for polymorphonuclear-elastase evaluation were sent to the laboratory and managed there according to routine protocols. AP was classified as mild or severe according to the Atlanta classification, whereas polymorphonuclear-elastase results were kept blind. Results were shown as mean+/-SD and compared using Student's t-test for unrelated samples. The accuracy of the test for the prognostic evaluation of AP was calculated after drawing the corresponding receiver operator curve.

Results: Fifty patients (23%) suffered from severe AP. The plasma levels of polymorphonuclear elastase were 217.8+/-93.5 microg/l in patients with severe AP and 68.1+/-32.7 microg/l in those with mild disease (P<0.001). The sensitivity and specificity of the test for the detection of severe AP were 92 and 91%, respectively, for an optimal cut-off value of 110 microg/l. The positive and negative predictive values for a prevalence of severe disease of 20% were 78 and 96%, respectively. The area under the receiver operator curve was 0.956.

Conclusion: Quantification of plasma polymorphonuclear-elastase levels is a very accurate method for the early prognostic evaluation of AP, and is easily applicable in the clinical setting.