An evaluation of the one-day NBT-PABA/14C-PABA in the assessment of pancreatic exocrine insufficiency.

The one-day NBT-PABA/14C-PABA has been performed on 58 consecutive subjects with suspected or established pancreatic disease. 23 of these were normal subjects, 12 were subsequently shown to have other gastrointestinal disease and 23 had proven pancreatic disease. A PABA excretion index (PEI) has been calculated and, using our lower limit of normality (0.61), the test has shown an overall sensitivity of 83% and specificity of 89%. False positives were a particular problem in the other gastrointestinal disease group (25%). There was a close correlation between PEI and Lundh mean tryptic activity (r = 0.89). These results indicate that this test is a satisfactory screening test for pancreatic exocrine disease and is easier to perform with less likelihood of error than many other non-invasive tests of pancreatic function.