Trypsinogen-1, -2 and tumour-associated trypsin-inhibitor in bile and biliary tract tissues from patients with biliary tract diseases and pancreatic carcinomas.

The bile concentrations of trypsinogen-1, -2 and tumour-associated trypsin-inhibitor (TATI) were determined in 23 patients with benign biliary tract disease, two with biliary tract cancer, and in 15 with pancreatic cancer. We also examined the trypsinogen and TATI expression by immunohistochemistry in tissue specimens from biliary tract cancer and non-neoplastic extrahepatic biliary tract. High levels of trypsinogen-1, trypsinogen-2, and TATI occur in bile of most patients. In contrast to the trypsinogens, the levels of TATI were significantly higher in patients with malignant disease than in those with benign diseases (p=0.04). There was no significant correlation between trypsinogen-2 and amylase (r=0.13, p=0.40), indicating that the occurrence of trypsinogen in bile is not a result of reflux of pancreatic fluid into the bile duct. Immunohistochemically, trypsinogen-2 was detected in five and TATI in 12 out of 15 non-neoplastic biliary tract specimens, and in four and seven out of 11 cholangiocarcinomas, respectively. High concentrations of trypsinogen-1, trypsinogen-2 and TATI occur in the bile of patients with non-neoplastic and malignant biliary tract disease and in patients with pancreatic cancer. At least part of the trypsinogen-2 and TATI found in bile appears to be derived from the biliary epithelium itself.