We sought to examine the relationship between C-reactive protein (CRP) and clinical, endoscopic, histologic, and radiographic activity in inflammatory bowel disease (IBD).
All IBD patients at our institution between January 2002 and August 2003 who had a CRP, colonoscopy, and either small bowel follow-through (SBFT) or CT enterography (CTE) performed within 14 days were identified. Clinical activity was assessed retrospectively through review of the medical record. Logistic regression was used in Crohn's disease (CD) patients to estimate the odds ratio (OR) with 95% confidence intervals for an elevated CRP. Associations were assessed using Fisher exact test in ulcerative colitis (UC) patients due to small sample size.
One-hundred four CD patients (46% males) and 43 UC and indeterminate colitis patients (44% males) were identified. In CD patients, moderate-severe clinical activity (OR, 4.5; 95% CI, 1.1-18.3), active disease at colonoscopy (OR, 3.5; 95% CI, 1.4-8.9), and histologically severe inflammation (OR, 10.6; 95% CI; 1.1-104) were all significantly associated with CRP elevation. Abnormal small bowel radiographic imaging was not significantly associated with CRP elevation. In UC patients, CRP elevation was significantly associated with severe clinical activity, elevation in sedimentation rate, anemia, hypoalbuminemia, and active disease at ileocolonoscopy, but not with histologic inflammation.
CRP elevation in IBD patients is associated with clinical disease activity, endoscopic inflammation, severely active histologic inflammation (in CD patients), and several other biomarkers of inflammation, but not with radiographic activity.
1Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota
2Division of Biostatistics, Mayo Clinic College of Medicine, Rochester, Minnesota
*Reprints: Edward V. Loftus, Jr., MD, Division of Gastroenterology and Hepatology, Mayo Clinic, 200 First Street, S.W. Rochester, Minnesota 55905
Received 25 May 2005; Accepted 26 May 2005
Presented in part at the 105th Annual Meeting of the American Gastroenterological Association, Digestive Disease Week, May 15-20, 2004, New Orleans, Louisiana.