Aim: To explore if C-reactive protein (CRP) levels might serve as a prognostic factor with respect to the clinical course of Crohn's disease and might be useful for classification.
Methods: In this retrospective cohort study we enrolled 94 patients from the inflammatory bowel disease (IBD) database of the University Medical Centre Utrecht. CRP levels during relapse were correlated with the number of relapses per year. Severity of relapses was based on endoscopic reports and prednisone use. Furthermore, patients were categorized in a low or high CRP group based on their CRP response during relapse and demographic and clinical features were compared.
Results: Overall, a positive correlation between CRP levels, number of relapses, and severity of relapse was found (respectively rs = 0.31, P < 0.01 and rs = 0.50, P < 0.001). Employing a cut-off level of 15 mg/L, the index CRP level was found to discriminate patients with respect to the number of relapses per year, as well as for severity of relapses (respectively 0.25 +/- 0.16 vs 0.36 +/- 0.24, P < 0.05 and 4.4 +/- 1.2 vs 3.2 +/- 1.1 on a 10-point visual analogue scale, P < 0.001 for the high CRP and low CRP groups respectively). In addition, the high CRP group showed more cumulative days of prednisone use per year (107 +/- 95 vs 58 +/- 48, P < 0.05), as well as a better response to infliximab (93 % vs 33 %, P = 0.06).
Conclusion: A higher CRP level during relapse seems to be associated with a more severe clinical course of disease.