EVALUATION AND VALIDATION OF A CROHNS-DISEASE INFLAMMATORY ACTIVITY INDEX REFLECTING PATTERN OF ENDOSCOPIC SEVERITY

Background: This study was designed to investigate objective variables assessing the inflammatory activity of Crohn's disease accessible for routine management and their suitability to act as surrogate indicato rs for endoscopic alterations. Methods: Thirty-six patients were inclu ded in a prospective study and underwent endoscopic investigation, 18 with clinically exacerbated disease and 18 after acute-phase conservat ive therapy. The endoscopic findings were classified to define the dep endent variable, yielding two categoric levels: acute active disease a nd remission. The extent of affected mucosal area was not taken into c onsideration. The serum variables alpha(1)-antitrypsin, acid alpha(1)- glycoprotein (AGP), C-reactive protein (CRP), sialic acids, prealbumin (PAB), and albumin were used as independent variables to predict the dependent variable. To compare the results with common indices, the Cr ohn's Disease Activity Index (CDAI) and van Hees Index were calculated . Results: The following model was calculated by stepwise logistic reg ression analysis: if AGP (mg/dl) - 4.2 x PAB (mg/dl) greater than or e qual to 0.8, then endoscopically active disease will be predicted with a sensitivity of 100% and a specificity of 95% (P < 0.001). The predi ctive values of the single variables, CDAI, and van Hees Index were lo wer. For validation of results an analogous study was performed includ ing 44 patients, 29 with active disease and 15 controls. The existence of the model was confirmed, again showing high values for sensitivity (86%) and specificity (100%). Conclusions: On a qualitative level foc using on clinical relevance, the endoscopic and biologic findings of C rohn's disease are highly associated. In addition to clinical assessme nt, usage of the developed index as a rationale contributing to therap eutic decisions in the short- and long-term management might be reason able.