Pancreatic exocrine insufficiency: Comparing fecal elastase 1 with 72-h stool for fecal fat estimation

Identification of pancreatic exocrine insufficiency (PEI) is important in the management of chronic pancreatitis. The 72-h stool for fecal fat estimation (FFE) has long been considered a gold standard indirect test for the diagnosis of PEI. However, the test is cumbersome for both patients and laboratory personnel alike. In this study, we aimed to assess fecal elastase 1 (FE1) as an alternate to FFE for the diagnosis of PEI.

In all, 87 consecutive patients diagnosed with chronic pancreatitis were included in this study. FFE and FE1 estimation was done for all the patients. For FE1, two cutoffs (<100 and <200 μg) were selected to define pancreatic exocrine insufficiency. The sensitivity, specificity, and positive and negative predictive values for the two cutoffs were estimated. Kappa statistics was used to assess degree of agreement between both tests.

All patients completed the study and were included in the analysis. The sensitivity, specificity, and positive and negative predictive value and PABAK (prevalence and bias adjusted kappa) for FE1 <100 μg was 84.9, 47.6, 83.6, 50, and 0.52, respectively. For FE1 <200 μg, it was 90.9, 9.5, 75.95, 25, and 0.43, respectively.

FE1 is a sensitive test; however, it does not have a good agreement with FFE. FE1 may be used as screening test for PEI in patients with chronic pancreatitis.