THE ROLE OF NEOPTERIN IN ASSESSING DISEASE-ACTIVITY IN CROHNS-DISEASE- CLASSIFICATION AND REGRESSION TREES

Neopterin, a product of human monocytes/macrophages stimulated by gamm a-interferon, was previously found to be correlated with clinical acti vity of Crohn's disease. The present investigation attempted to identi fy more precisely the role of neopterin for assessment of clinical act ivity in a multivariate setting. A broad panel of clinical and laborat ory variables was obtained on 76 patients. Neopterin was determined in urine by high performance liquid chromatography. Using a 4-point clin ical activity score as dependent variable, multivariate linear discrim inant analyses were performed in order to identify subsets of statisti cally independent laboratory activity indices. Neopterin was shown to be an independent indicator for clinical activity. The significant var iables were then tested together with the eight constituent variables of the Crohn's Disease Activity Index. The resulting model, which cons isted of the three laboratory variables-erythrocyte sedimentation rate , serum protein and neopterin, together with pain score-was further su bjected to two multivariate techniques for comparison: polychotomous l ogistic regression analysis and the technique of classification and re gression trees. By all methods, neopterin was included into the multiv ariate models, confirming that its determination aids in the assessmen t of clinical activity in Crohn's disease.