N-benzoyl-tryrosyl para-aminobenzoic acid (NBT-PABA)
The NBT-PABA test is the most widely used test of pancreatic exocrine insufficiency in the UK with a specificity of 95% and a sensitivity of 80-90%.
NBT-PABA is hydrolysed by pancreatic chymotrypsin to PABA which is then is absorbed and excreted in the urine. To control for variation in PABA absorption a trace quantity of C14-labelled PABA is given with the bulk unlabelled NBT-PABA.
Last reviewed 01/2018