C-reactive protein and monitoring the activity of Crohn's disease

Biological treatments (anti-tumor necrosis factor-a antibody, mitogen-activated protein kinase inhibitors) and azathioprine given to patients with Crohn's disease (CD) provide the opportunity for mucosal healing. This fact has given rise to the question of whether clinical relief or mucosal healing is the treatment goal in CD. If only clinical relief is sought, current indexes should be reevaluated. In this study, investigators explored the relationship between findings of endoscopic activity, Crohn's Disease Activity Index (CDAI) scores, and C-reactive protein (CRP). This study attempted to clarify the relationship between a high CDAI score (CDAI >150), raised serum CRP, and endoscopic activity in patients with CD. This retrospective study included 115 patients with Crohn's ileocolitis and colitis. CDAI score, CRP level, and mucosal lesions were compared with the chi2 test. The relation between endoscopic activity and raised CRP was significant (P=.001), unlike the association of endoscopic activity with CDAI (P=.287). Mucosal activity was most intense in patients who had both a high CDAI and a raised CRP (84%). No significant difference in endoscopic activity was noted, however, between patients with raised CRP + high CDAI, raised CRP + low CDAI, normal CRP + high CDAI, and normal CRP + low CDAI (P=.113). CRP seemed to be more sensitive than CDAI in the evaluation of patients with CD. The relationship between high CDAI, raised CRP, and the presence of colonoscopic mucosal activity was poor. Therefore, CDAI and CRP are not viewed by the authors as reliable measures of CD activity.