Serum PABA and fluorescein in the course of Bz-Ty-PABA and pancreolauryl test as an index of exocrine pancreatic insufficiency.

Forty-six subjects (20 chronic pancreatitis, 7 chronic liver disease, 7 recovered from acute pancreatitis, 2 Crohn's disease, and 10 healthy controls) classified by S-C test as having normal pancreatic function (26 subjects), or moderate (10 subjects) and severe (10 cases) pancreatic insufficiency, were given, on different days, 1 g of oral PABA or 348 mg of oral fluorescein dilaurate. At the 1st, 2nd, and 4th hours (PABA) and the 2nd, 4th, and 6th hours (fluorescein) serum samples were taken for assay. In the presence of severe exocrine pancreatic insufficiency, the sensitivity of the fluorescein serum levels was higher than that observed for the PABA (100% and 80%, respectively), and quite similar to that shown by the urinary tests (100% and 70%, respectively). On the contrary, in presence of moderate pancreatic insufficiency, both the urinary test (pancreolauryl and (PABA) give a sensitivity higher than that found in the serum tests (30-40% and 10-30%, respectively). The parallel combination of both the serum or urinary tests does not significantly improve the sensitivity of the single test. These results suggest that the serum PABA and serum fluorescein tests can be valid choice when a prolonged urinary collection is difficult, i.e., in children and in elderly patients. However, the slight diagnostic gain does not justify the routine use of both urinary and serum tests.