Evaluation of Faecal Calprotectin S100A8/S100A9 Levels in Patients Suffering from Irritable Bowel Syndrome: A Cross-sectional Study

Abstract

Introduction: Irritable Bowel Syndrome (IBS) is a common functional bowel disorder which remains a clinical challenge with limited therapeutic options. The diagnosis of IBS is made by the Rome IV criteria. Patients suffering from IBS often have impaired poor quality of life. Distinguishing IBS from Inflammatory Bowel Diseases (IBD) can be difficult, especially with mild disease activity. Both conditions share a symptom complex with abdominal pain and altered bowel habits but potentially have different treatments for each disorder. Aim: To evaluate Faecal Calprotectin S100A8/S100A9 Levels (FCL) in IBS patients and compare those levels with patients suffering from the IBD group. Materials and Methods: This was a cross-sectional study conducted for a period of one year from June 2022 to May 2023 at the Department of Pathology in collaboration with the Department of Medicine, Khaja Bandanawaz (KBN) University- Faculty of Medical Sciences, Kalaburagi Karnataka, India. The study included 130 patients aged between 18 and 65 years with chronic diarrhoea, consisting of 90 cases in the IBS group and 40 cases in the IBD group for comparison. After obtaining clinical details, FCL were analysed by Fluorescence Immunoassay (FIA). Patients were subjected to colonoscopic evaluation, and biopsies were taken for processing. FCL, colonoscopic, and histopathological findings were evaluated in IBS patients and IBD patients, respectively. Data were analysed using the Statistical Package for Social Sciences (SPSS) version 24.0 software package. Quantitative data were expressed as mean±Standard Deviation (SD). Qualitative data were expressed using U-test Fisher’s-exact and Chi-square test, where a p-value <0.05 was considered statistically significant. Results: The age range was from 18 to 65 years with a male to female ratio of 1:2 and a mean age of 42.2 years. Among the 90 IBS cases, IBS-diarrhoea predominant was the largest subgroup with 65 patients (72.2%) clinically. Seventeen IBS cases showed elevated FCL levels, with four patients having FCL levels higher than those in IBD cases in a quiescent stage. The mean±SD FCL levels in the IBS subgroup were 80.45±76.4 μg/g Out of the 17 cases with elevated FCL levels, 10 showed features of microscopic colitis {lymphocytic colitis (7), collagenous colitis (2), indeterminate (1)}, respectively. Thirty-seven IBD patients had elevated FCL levels, with a mean±SD FCL level in the IBD subgroup of 180.20 ± 386.4 μg/g, and 12 patients (30.0%) had levels higher than 500 μg/g. Conclusion: The study concluded that FCL levels are elevated in IBS patients also. The FCL levels in the IBS-diarrhoea subgroup were elevated more than the IBD-quiescent subgroup. IBS cases with elevated FCL levels showed positive colonoscopic findings and histopathological features of microscopic colitis on biopsy. These IBS cases require anti-inflammatory treatment as they do not respond to regular anti-IBS treatment. Furthermore, these IBS patients should be followed-up as they may potentially develop into future IBD cases.