Chromogranin A as a Novel Biomarker of Irritable Bowel Syndrome in Adults: A Systematic Review and Meta-Analysis.

Irritable bowel syndrome (IBS) is a chronic condition characterized by recurring abdominal discomfort and irregular bowel movements. Currently, IBS diagnosis lacks specific radiological, biochemical, or endoscopic markers. Chromogranin A (CgA), a gastrointestinal protein, shows variation between patients with IBS and healthy controls. This study aimed to evaluate differences in CgA concentrations between these groups. This review was conducted in 2023 using the PRISMA 2020 guidelines. All observational research was retrieved from MEDLINE, EBSCO-Host, ScienceDirect, and ProQuest electronic databases using a predefined search strategy. Study quality was assessed using the Newcastle-Ottawa Scale (NOS), and meta-analysis was conducted using Review Manager (RevMan) 5.4. Nine out of 14 studies eligible for meta-analysis revealed significantly higher CgA cell density (P=0.0001) in all patients with IBS compared with controls. This difference persisted across colon regions (left: P=0.04, right: P=0.0009) and duodenum (P<0.00001). Subgroup analysis found no significant disparity in CgA cell density between diarrhea and constipation-predominant IBS within the duodenum or colon. CgA cell density showed trends toward IBS compared with control groups, with significant concentration differences found in the duodenum, left, and right colon. Therefore, current findings might offer a histopathological approach to confirm the IBS diagnosis.