Clinically active Crohn's disease in the presence of a low C-reactive protein.

Objective . Clinical interest in C-reactive protein (CRP) – a component of the innate immune system – has focused mainly on its worth as an indicator of disease activity. There has been a resurgence of interest in CRP in the Crohn's disease (CD) literature because several trials of new treatments for active CD have been characterized by both a large proportion of patients with low CRP ( ?200. The low CRP group was compared with patients in the raised CRP group for a range of clinical variables as well as the major NOD2 variants. Results . There were data sets for 223 CD patients, with a mean disease duration of 12 years. Of these, 22 patients fulfilled the criteria for low CRP. The low CRP group (group 1) showed significant differences for disease site ( p 2 versus 25.0 kg/m 2 ). Groups 1 and 2 did not differ with respect to Vienna behaviour at diagnosis, smoking, appendicectomy, extra-intestinal manifestations of CD, or NOD2 SNP variants. There was a trend for low CRP patients with previous ileal resection to evolve to a stricturing phenotype. Fat wrapping was noted in 11/13 (85%) of low CRP patients undergoing ileal resections. Conclusions . Patients with CD and a persistently low CRP in the face of active disease were characterized by an almost exclusive ileal disease distribution and a low BMI, compared to those with a raised CRP. These patients had a similar frequency and distribution of NOD2/CARD15 variants. Stricturing ( v inflammatory or penetrating) behaviour may explain some low CRP. Despite the abnormally low BMI, fat wrapping was noted in the majority of low CRP patients undergoing ileal resection. [ABSTRACT FROM AUTHOR]