Published online Apr 28, 2021. doi: 10.3748/wjg.v27.i16.1828
Peer-review started: January 27, 2021
First decision: February 25, 2021
Revised: March 2, 2021
Accepted: April 7, 2021
Article in press: April 7, 2021
Published online: April 28, 2021
Mucosal healing (MH) has emerged as a key therapeutic target in inflammatory bowel disease (IBD), and achievement of this goal is documented by endoscopy with biopsy. However, colonoscopy is burdensome and invasive, and substitution with an accurate noninvasive biomarker is desirable.
To summarize published data regarding the performance of noninvasive biomarkers in assessing MH in IBD patients.
We conducted a systematic review of studies that reported the performance of biomarkers in diagnosing MH in patients with IBD. The main outcome measure was to review the diagnostic accuracy of serum and fecal markers that showed promising utility in assessing MH.
We screened 1301 articles, retrieved 46 manuscripts and included 23 articles for full-text analysis. The majority of the included manuscripts referred to fecal markers (12/23), followed by circulatory markers (8/23); only 3/23 of the included manuscripts investigated combined markers (serum and/or fecal markers). Fecal calprotectin (FC) was the most investigated fecal marker for assessing MH. In ulcerative colitis, for cutoff levels ranging between 58 mcg/g and 490 mcg/g, the sensitivity was 89.7%-100% and the specificity was 62%-93.3%. For Crohn’s disease, the cutoff levels of FC ranged from 71 mcg/g to 918 mcg/g (sensitivity 50%-95.9% and specificity 52.3%-100%). The best performance for a serum marker was observed for the endoscopic healing index, which showed a comparable accuracy to the measurement of FC and a higher accuracy than the measurement of serum C-reactive protein.
Several promising biomarkers of MH are emerging but cannot yet substitute for endoscopy with biopsy due to issues with reproducibility and standardization.
Core Tip: Identification of performant biomarkers that can substitute for repeated and cumbersome invasive procedures is a priority. Although therapeutic success in both Crohn’s disease and ulcerative colitis remains to be clearly defined, mucosal healing has been one of the main therapeutic targets stipulated by recent recommendations. In inflammatory bowel disease mucosal healing, several serum- and fecal-based markers have shown promising results; however, a multimarker may improve the diagnostic accuracy of any single independent biomarker.