Concentrations of pancreatic secretory trypsin inhibitor (PSTI), acute phase proteins, and neopterin in Crohn's disease. Comparison with clinical disease activity and endoscopical findings

Abstract

The usefulness of pancreatic secretory trypsin inhibitor (PSTI) as a marker of chronic inflammation was studied in patients with Crohn's disease. Pancreatic secretory trypsin inhibitor was compared with other laboratory tests (C-reactive protein, orosomucoid, and urinary neopterin), for evaluation of disease activity as measured by a clinical scoring system and endoscopical findings. The clinical utility of the tests was compared by four different methods. All tests showed significant differences in laboratory values between inactive and severely active disease. Using earlier established cut-off values PSTI showed the best combination of sensitivity and specificity for differentiation between inactive and severely active disease. When the efficacy of the test was compared by ROC-eurve analysis, neopterin and orosomucoid produced the best combination of sensitivity and specificity, but for both assays the earlier established cut-off levels were too high for optimal separation between active and inactive disease. There was a poor agreement between endoscopically and clinically determined disease activity and the laboratory tests correlated better with clinical activity. The present study shows that serum PSTI reflects changes in the clinical activity of Crohn's disease equally well as C-reactive protein, which previously has been found to be an useful index of disease activity.

Key Words:

• C-reactive protein
• Crohn's disease activity index
• Neopterin
• orosomucoid
• pancreatic secretory trypsin inhibitor