Introduction: Indirect tests of exocrine pancreatic function are thought to be of little sensitivity and specificity in mild to moderate insufficiency as compared with direct function tests. Direct tests, which are claimed to be the "gold standard" of functional diagnosis, are too complicated to be performed on great numbers of patients and are not standardized.
Aims: To characterize the use of an indirect function test (fecal elastase 1 measurements determined independently from a direct test), in this study we compared it with the gold standard of morphologic diagnosis, endoscopic retrograde cholangiopancreatography (ERCP).
Methodology: Data for 213 patients who underwent ERCP (104 males and 109 females; mean age, 54 years [8-89]) were collected prospectively, including fecal elastase 1 measurements and clinical and ERCP data.
Results: Elastase 1 findings correlated with pancreatic duct changes (p < 0.05). At a cutoff point of 200 microg/g, the positive predictive value of elastase 1 measurement for moderate/severe duct changes was 90.4%, and for any duct changes it was 96.8%. The sensitivity was only 45.3% for any duct changes but 76.5% for severe changes. Specificity for moderate/severe changes was 86%.
Conclusion: Fecal elastase 1 measurements appear to be valuable for characterizing patients at high risk for chronic pancreatitis, even if their sensitivity is lower than that of direct tests.