NBT-PABA test

NBT-PABA test

The N-benzoyl-L-tyrosyl-p-aminobenzoic acid test, a noninvasive test primarily used to measure the function of the exocrine pancreas. The test is performed by administering NBT-PABA to patients with suspected chronic pancreatitis and measuring the amount of PABA excreted in the urine. In patients with chronic pancreatitis, chymotrypsin is not released by the exocrine pancreas into the gastrointestinal tract; NBT is not cleaved from PABA, and thus the excretion of PABA in the urine is diminished.