The usefulness of serum PABA measurement after BT-PABA administration in the diagnosis of chronic pancreatitis.

We examined the maximal serum PABA concentration within 3 hrs (MS-PABA) and the 6 hr urinary PABA recovery (6 hr U-PABA) after BT-PABA administration, PABA excretion index, and chymotrypsin secretory response to caerulein-secretin stimulation in ten control subjects and fifteen patients with chronic pancreatitis diagnosed on the basis of pancreatograms. The results suggested that MS-PABA can distinguish the patients with definite irregular dilatation of the main pancreatic duct from the controls, but not those with localized irregular dilatations of the side branches from the controls. MS-PABA showed a significant correlation with 6 hr U-PABA, PABA excretion index, chymotrypsin output and bicarbonate output. This modified method was shown to be useful in the diagnosis of chronic pancreatitis with unequivocally abnormal pancreatograms and/or markedly decreased chymotrypsin secretion. This modification will serve to simplify the BT-PABA test by eliminating urinary collection and shortening the procedure time.