Fecal elastase test: evaluation of a new noninvasive pancreatic function test.

Abstract

Pancreatic elastase is highly stable along the intestinal tract. A new ELISA is commercially available to measure human specific elastase-1 concentration in stool. We evaluated the behavior of this fecal elastase test (FET) compared with other indirect pancreatic function tests in patients with chronic pancreatitis (CP). A total of 69 patients were included in the study, 20 of whom were diagnosed with CP according to the findings on ERP and CT; 13 patients had other pancreatic diseases, and the remaining 36 patients had gastrointestinal or hepatic disorders. All patients' elastase-1 concentrations and chymotrypsin activities [fecal chymotrypsin test (FCT)] were measured, and the serum pancreolauryl test (PLT) was performed. Similar to PLT, fecal elastase concentration was significantly decreased in patients with moderate and severe CP (assessed by ERP) compared with patients with extrapancreatic disorders. However, and contrarily to PLT, FET was not affected by gastric resection, malabsorption due to intestinal disease, or marked alteration of the gastric motility. The sensitivity of FET was 100% for moderate to severe CP but 0% for mild CP; the specificity was 83%. Compared with other indirect pancreatic function tests, FET appears to be as sensitive as PLT and as specific as FCT, and it is clearly more specific than PLT and more sensitive than FCT. Unlike FCT, FET was not affected by oral enzyme supplementation. FET is a simple and accurate functional test for CP, and it is hardly influenced by extrapancreatic disorders or therapy with exogenous enzymes.