Circulating anti-cytolethal distending toxin b and anti-vinculin antibodies as biomarkers in community and healthcare populations with functional dyspepsia and irritable bowel syndrome

Abstract

OBJECTIVES: Anti-cytolethal distending toxin B (CdtB) and anti-vinculin antibodies have been proposed as biomarkers that discriminate irritable bowel syndrome (IBS) diarrhea from inflammatory bowel disease; however, it is unknown whether they can also discriminate patients with IBS and IBS subtypes and functional dyspepsia (FD) from healthy individuals in the general population. We aimed to determine whether anti-CdtB and anti-vinculin can discriminate IBS and FD from health and from organic gastrointestinal (GI) disease. METHODS: Adults were enrolled from 2 Australian studies: (i) a random, population-based study (n=331) with subjects diagnosed with IBS (n=63) or FD (n=61) by modified Rome III criteria or healthy control subjects (n=246) who did not meet criteria for IBS and/or FD and (ii) an outpatient-based study with subjects diagnosed with IBS (n5256) and/or FD (n555) or organic GI disease (n5182) by an independent clinician. Serum levels of anti-CdtB/anti-vinculin antibodies were determined by enzyme-linked immunosorbent assay. RESULTS: There was a significantly higher mean value of anti-CdtB in FD vs healthy controls (mean=2.46 [SD=0.72] vs mean=2.14 [SD=0.77]; P=0.005) and IBS/FD overlap vs healthy controls (mean=2.47 [SD=0.78] vs mean=2.14 [SD=0.77]; P=0.02). There were no significant differences in anti-CdtB in IBS and FD outpatients or IBS/FD subgroups compared with patients with organic GI disease. In terms of anti-vinculin, there were no significant differences between IBS and FD and healthy controls or between IBS and FD and organic GI disease controls. DISCUSSION: We did not confirm that anti-CdtB/anti-vinculin discriminated IBS diarrhea from organic GI disease in Australian subjects. However, we did find higher anti-CdtB in FD and IBS/FD overlap vs healthy controls. Postinfectious FD may be more common than currently recognized.