Published online Dec 14, 2017. doi: 10.3748/wjg.v23.i46.8235
Peer-review started: August 1, 2017
First decision: September 6, 2017
Revised: September 28, 2017
Accepted: November 2, 2017
Article in press: November 2, 2017
Published online: December 14, 2017
Inflammatory bowel disease (IBD) is characterized by periods of relapsing-remitting. At present, most clinicians monitor IBD activity and guide therapeutic decisions based on clinical activity indexes. However, emerging data show that clinical assessment indexes correlate poorly with endoscopic activity and IBD patients with clinically quiescent disease may still have residual mucosal inflammation. An endoscopic procedure is considered the gold standard for assessing disease activity. However, the endoscopy is invasive, uncomfortable, and expensive.
A simple, acceptable, and specific evaluation is needed to play an adjunctive role in the assessment of IBD activity. The specific and noninvasive evaluation could instruct clinicians to timely choose reasonable therapy regimen and predict prognosis. Furthermore, a new evaluation that can detect increased disease activity earlier before any clinical symptoms have occurred could change disease course, enabling the most cost-effective use of medical resources.
The main objective of this study was to assess the efficacy of noninvasive evaluations for the disease activity in colonic or ileo-colonic Crohn’s disease (CICD), CD-related surgery, and ulcerative colitis (UC) patients and further to optimize the accuracy of those noninvasive evaluations in detecting active residual mucosal inflammation in IBD patients in clinical remission. In our study we confirmed the efficacy of fecal calprotectin (FC) and the new clinical FC activity (CFA) in assessing disease activity in CICD and UC patients. In future, clinicians and researchers could use FC to recognize an imminent endoscopic flare. What’s more, FC could be measured frequently as a clinical activity index to detect preclinical mucosal inflammation in clinical remission patients.
In total, 136 consecutive IBD patients and 25 recruited IBS patients were enrolled. For all IBD patients, the day before the endoscopy, fecal and blood samples were collected to measure FC, CRP, ESR, and PCT. At the same time, the patients were asked to complete a case report to calculate their clinical activity index (CDAI/CAI). Then, endoscopic activity was determined for CICD patients with the “simple endoscopic score for Crohn’s disease” (SES-CD), CD-related surgery patients with the Rutgeerts score, and UC patients with the Mayo score. The efficacies of these evaluations to predict the endoscopic activity were assessed by Mann-Whitney test, χ2 test, Spearman’s correlation, and multiple linear regression analysis. In our study, multiple linear regression analysis with stepwise deletion was performed based on FC, CDAI/CAI, CRP, ESR, and PCT to construct a combined score, clinical FC activity (CFA), which could best predict the endoscopy activity. In clinical scenario, clinicians could identify endoscopic active disease more accurately with CFA through a short inquiry and a FC test.
We found that FC and clinical FC activity (CFA) are useful, non-invasive, and sensitive stool markers for gut inflammation in both CICD and UC patients. However, the standard collection of fecal sample and best cutoff to predict endoscopic activity are needed to be solved.
This was the first study performed in China for disease activity analysis in the three groups of IBD patients separately. We also constructed a clinical FC activity (CFA) index to more accurately assess disease activity. Moreover, we found that FC had ability to detect active residual mucosal inflammation in IBD patients in clinical remission. Indeed, we also found that IBD patients in endoscopic remission still had significantly higher levels of FC when compared with IBS patients. A high level of FC could be a reliable marker of persistent active microscopic inflammation. Then FC remission may indicate deep remission at histopathology level, which was proven to be a strong predictor of favorable prognosis in IBD. In future, the next step is to use FC to guide the clinicians to adjust the treatment regimen. We can schedule regular FC measurement and compare the change from baseline level to reflect the degree of response to treatment.
In our study, we confirmed the efficacy of FC in assessing disease activity in IBD patients. In future, we recommend periodic FC measurements instead of a single measurement in monitoring disease activity and deciding the treatment regimen. The clinical remission and biomarker healing could be the new therapeutic goals in IBD patients. To achieve those goals, multicenter, large-sample, randomized clinical trials are warranted to prove their value in clinical practice.