Impaired fibrinolysis and increased protease levels in gastric and duodenal mucosa of patients with active duodenal ulcer.

OBJECTIVES: Cathepsin B and L (cysteine proteases), urokinase- and tissue-type plasminogen activators (serine proteases), and type-1 inhibitor are involved in gastric mucosal injury. We determined tissue protease levels in duodenal ulcer and their relationship to ulcer phase, bleeding tendency, Helicobacter pylori infection, and use of H2-blockers.
METHODS: Endoscopic biopsies of antral and duodenal mucosa were obtained from 61 patients with active or healed duodenal ulcer and control subjects. Antigen concentrations were measured by ELISA.
RESULTS: Significantly higher levels of cathepsins, urokinase-type plasminogen activator, type-1 inhibitor, and significantly lower levels of tissue-type plasminogen activator were found in active ulcers. Bleeders had the highest cathepsins and urokinase-type plasminogen activator levels. Higher levels of urokinase-type plasminogen activator, cathepsin B, and type-1 inhibitor were observed in Helicobacter pylori-positive patients.
CONCLUSIONS: Our results suggest that impaired fibrinolysis (tissue-type plasminogen activator), intramucosal proteases (cathepsins), tissue remodeling, and angiogenesis (urokinase-type plasminogen activator and type-1 inhibitor) are involved in duodenal ulcer formation and healing.