Elsevier

Digestive and Liver Disease

Volume 39, Issue 11, November 2007, Pages 1006-1010
Digestive and Liver Disease

Alimentary Tract
Correlation between levels of C-reactive protein and clinical activity in Crohn's disease

https://doi.org/10.1016/j.dld.2007.06.015Get rights and content

Abstract

Aims

To determine the factors associated with an increased C-reactive protein level in Crohn's disease patients and to seek a correlation between the C-reactive protein value and the Crohn's disease activity index.

Methods

We prospectively studied 103 Crohn's disease patients, 76% of whose disease was active at the time of inclusion. C-reactive protein measurement was carried out on all patients. An increased C-reactive protein level was defined as ≥10 mg/L.

Results

The median C-reactive protein rate was 53.9 mg/L (ranging from 1 to 228 mg/L). An increased C-reactive protein was found in 77 patients (75%). By univariate analysis, ileocolic localization, severity of the flare, erythrocyte sedimentation rate, leukocyte and platelet count, fibrinogen, albumin, serum calcium and Crohn's disease activity index were found to be associated to elevated C-reactive protein values. By multivariate analysis, independent factors associated with an increased C-reactive protein level were: ileocolic localization (p = 0.02; OR [95% CI]: 2.84 [1.25–9.52]) and moderate or severe disease activity (p = 0.001; OR [95% CI]: 4.20 [1.92–8.64]). A statistically significant association between the Crohn's disease activity index score and the C-reactive protein level was found in our study (r = 0.302; p = 0.001). The optimal C-reactive protein threshold value that separates patients with moderate to severe disease (Crohn's disease activity index > 220) from the others was calculated to be 19 mg/L with a sensitivity of 76.4% and a specificity of 56.2%.

Conclusion

The C-reactive protein level is correlated to disease activity in Crohn's disease. Its role seems to be essential in predicting moderate and severe disease activity.

Introduction

Crohn's disease (CD) is characterized by flare-ups alternating with periods of remission. The assessment of CD activity is key when it comes to determining the therapeutic approach and to predicting the response to treatment [1]. This assessment can be carried out using clinical disease activity indices like the Crohn's disease activity index (CDAI), the most tested and proven clinical score in CD [2]. Other ways to measure CD activity are endoscopical and histological examination, accurate but invasive and expensive.

Biochemical markers are widely used in clinical practice in CD to measure inflammation and mirror disease activity. C-Reactive Protein (CRP), an acute phase reactant, is one of the most commonly used markers [3]. Its value is often elevated in patients with severe disease. Several studies found a positive correlation between CRP levels and CD activity based on endoscopical, histological and radiological findings or clinical scores, such as the Van Hees index [4], [5], [6]. However, although CDAI is the most used clinical score in CD, the correlation between CRP levels and CDAI has been poorly documented [3].

The aims of our study are to:

  • -

    Determine factors associated with an increased CRP level in CD patients.

  • -

    Examine the correlation between CRP levels and clinical activity, as measured by CDAI.

Section snippets

Patients

We prospectively studied 103 consecutive CD patients recruited in our department between January 2005 and June 2006. Exclusion criteria were current associated malignancy, previous intestinal resection and infection within the previous month.

Methods

The disease duration was specified for all patients. The disease site was determined either by endoscopical or radiological investigations carried out within a period of 6 months before the time of inclusion. The presence of anal fistula, and extra

Study population

Characteristics of included patients are represented in Table 1. At the time of inclusion, 78 patients (76%) had an active disease, 25 (24%) were in remission. The disease activity was found mild, moderate and severe in respectively 23, 35 and 20 patients. At the time of the blood tests, 14 patients were being treated with azathioprine and 7 with mesalazine. No one was undergoing steroid treatment at the moment of inclusion, although 23 patients had received prior corticosteroid treatment.

CRP values

The

Discussion

The prevalence of Crohn's disease varies geographically. Tunisia is considered as a zone of low incidence. In fact, in a study concerning east-central Tunisia, the incidence is about 1.24/10,000 inhabitants [7]. Our population differs from European and American patients by an absence of any significant association with NOD2/CARD15 gene polymorphism [8].

The CDAI is the most frequently used index in everyday practice as in clinical trials. However, the CDAI has some limitations: this score

Conflict of interest statement

None declared.

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