CONCENTRATIONS OF PANCREATIC SECRETORY TRYPSIN-INHIBITOR (PSTI), ACUTE-PHASE PROTEINS, AND NEOPTERIN IN CROHNS-DISEASE - COMPARISON WITH CLINICAL-DISEASE ACTIVITY AND ENDOSCOPIC FINDINGS

The usefulness of pancreatic secretory trypsin inhibitor (PSTI) as a m arker of chronic inflammation was studied in patients with Crohn's dis ease. Pancreatic secretory trypsin inhibitor was compared with other l aboratory tests (C-reactive protein, orosomucoid, and urinary neopteri n), for evaluation of disease activity as measured by a clinical scori ng 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 betwee n inactive and severely active disease. When the efficacy of the test was compared by ROC-curve analysis, neopterin and orosomucoid produced the best combination of sensitivity and specificity, but for both ass ays the earlier established cut-off levels were too high for optimal s eparation between active and inactive disease. There was a poor agreem ent 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.