Serological Test To Distinguish IBS From IBD

Serological Test To Distinguish IBS From IBD

The etiologies of IBS vary from infections to hypersensitivity and the disease is used to be diagnosed non-specifically. For the first time, researchers have developed a specific serological test to detect Irritable bowel syndrome in patients. This article gives an overview of this new kind of ELISA-based test specific for IBS that distinguishes IBS from Inflammatory Bowel Disease (IBD). IBS is a chronic health problem characterized by abdominal pain and altered pattern of bowel movement without any severe underlying damage. The disease affects 5-15% of the global population. Common symptoms associated with IBS are diarrhea (IBS-D), constipation (IBS-C), mixed symptom (IBS-M) or unspecific symptom (IBS-U). psychological problems such as anxiety and depression are also common to patients with IBS. Current IBS diagnosis is based upon exclusion of other disorders. Often times, IBS is misdiagnosed with another gastrointestinal disorder IBD because of symptomatic similarities. Development of serological marker for IBS: A clinical study has demonstrated that antibodies against two proteins, namely vinculin and CtdB can be used as serological biomarkers to diagnose IBS and distinguish it from IBD. Vinculin is a cytoskeletal protein involved in cell to cell adhesion. CdtB is an active component of Cytolethal distending toxins. These toxins are produced by certain gram-negative bacteria. CtdB causes cell cycle arrest and programmed cell death in certain mammalian cells which ultimately results in gastroenteritis. The basis of the current study: Previous research in animal models (infected by gastroenteritis-causing bacteria such as Campylobacter jejuni) identified the presence of CdtB toxins. Upon serological tests, the researchers detected host antibodies against CdtB that were able to cross-react with vinculin in the host gut and resulted in IBS-like phenotype. This leads to the assumptions that circulating anti-CdtB and anti-vinculin antibodies could be used as biomarkers for the diagnosis of IBS in human. Study design: Healthy volunteers and patients primarily diagnosed with IBS, IBD, celiac disease were recruited in a randomized clinical trial. Patients with IBD and celiac disease were recruited based on the presence of intestinal complaints and histologic confirmation of chronic inflammatory changes in the colon or small intestine. Patients with celiac disease were also required to have an elevated tTG and biopsy. Plasma levels of anti-CdtB and anti-vinculin antibodies were determined by ELISA (Enzyme-linked immunosorbent assay) and compared between the groups Key findings: Anti-CdtB & anti-vinculin titers were significantly higher in patients with IBS than patients with IBD, celiac disease or healthy individuals (P<0.001) Anti-CdtB titers were significantly higher in patients with IBS-D than other types of IBS (IBS-C, IBS-M) Anti-vinculin titers were significantly higher in patients with IBS-M than other types of IBS Anti-CdtB levels with an optical density value C2.80 differentiated IBS and IBD with sensitivity and specificity Anti-vinculin levels with an optical density value C1.68 differentiated IBS and IBD with sensitivity and specificity Conclusion: Gastroenteritis can lead to IBS symptoms. IBS (especially IBS-D) is generally diagnosed with the exclusion of the possibilities of other disorders. However, due to related symptoms, IBS is sometimes misdiagnosed as IBD. Now a serological test (vinculin and CdtB dependent) is available for specific diagnosis of IBS, distinguish IBS from IBD and distinguish between IBS subtypes (IBS-C, IBS-D, IBS-M). Sources: Pimentel M et al, Development and Validation of a Biomarker for Diarrhea-Predominant Irritable Bowel Syndrome in Human Subjects. PLoS One, 2015, 10(5): e0126438. Rezaie A et al, Assessment of Anti-vinculin and Anti-cytolethal Distending Toxin B Antibodies in Subtypes of Irritable Bowel Syndrome. Dig Dis Sci, 2017, 62(6):1480-1485.