The Ratio of Trypsin-2-α1-Antitrypsin to Trypsinogen-1 Discriminates Biliary and Alcohol-induced Acute Pancreatitis

Abstract

Abstract Background: Rapid determination of the etiology of acute pancreatitis (AP) enables institution of appropriate treatment. We evaluated the ability of trypsinogen-1, trypsinogen-2, trypsin-1-α1-antitrypsin (AAT), and trypsin-2-AAT in serum to identify the etiology of AP. Methods: The study consisted of 67 consecutive patients with AP admitted to Helsinki University Central Hospital. Forty-two had alcohol-induced AP, 16 had biliary AP, and 9 had unexplained etiology. Serum samples were drawn within 12 h after admission. Trypsinogen-1, trypsinogen-2, trypsin-1-AAT, and trypsin-2-AAT were determined by time-resolved immunofluorometric assays. Logistic regression was used to estimate the ability of the serum analytes to discriminate between alcohol-induced and biliary AP. The validity of the tests was evaluated by ROC curve analysis. Results: Patients with alcohol-induced AP had higher median values of trypsin-1-AAT (P = 0.065), trypsinogen-2 (P = 0.034), and trypsin-2-AAT (P <0.001) than those with biliary AP, who had higher values of amylase (P = 0.002), lipase (P = 0.012), and alanine aminotransferase (P = 0.036). The ratios of trypsin-2-AAT to trypsinogen-1, lipase, or amylase efficiently discriminated between biliary and alcohol-induced AP (areas under ROC curves, 0.92–0.96). Conclusions: Trypsinogen-2 and trypsin-2-AAT are markedly increased in AP of all etiologies, whereas trypsinogen-1 is increased preferentially in biliary AP. The trypsin-2-AAT/trypsinogen-1 ratio is a promising new marker for discrimination between biliary and alcohol-induced AP.