No difference in serum levels of B-cell activating receptor and antibodies against cytolethal distending toxin B and flagellin in post-infectious irritable bowel syndrome and chronic fatigue syndrome after Giardia infection

Kurt Hanevik; Christina Saghaug; Maren Aaland; Kristine Morch; Nina Langeland

doi:10.1002/jgh3.12724

No difference in serum levels of B-cell activating receptor and antibodies against cytolethal distending toxin B and flagellin in post-infectious irritable bowel syndrome and chronic fatigue syndrome after Giardia infection

JGH Open. 2022 Mar 14;6(3):185-188. doi: 10.1002/jgh3.12724. eCollection 2022 Mar.

Authors

Kurt Hanevik^{1

2}, Christina Saghaug^{1

2}, Maren Aaland¹, Kristine Morch^{1

2}, Nina Langeland^{1

2}

Affiliations

¹ Department of Clinical Science University of Bergen Bergen Norway.
² Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine Haukeland University Hospital Bergen Norway.

Abstract

Background and aim: Functional gastrointestinal disorders (FGIDs) and chronic fatigue syndrome (CFS) frequently occur as comorbid conditions to each other. A shared etiology of these syndromes has been proposed because of their shared symptomatology and triggering by infections. Antibodies against the bacterial antigens cytolethal distending toxin B (CdtB) and flagellin have been proposed to be biomarkers of irritable bowel syndrome (IBS), especially diarrhea-predominant IBS (IBS-D). It is unknown if they may also be associated with comorbid conditions such as CFS. On the other hand, elevated level of B-cell activating factor (BAFF) has been associated with CFS and inflammatory bowel disease (IBD) and subjective food intolerance.

Methods: We evaluated serum levels of anti-flagellin and anti-CdtB using an in-house enzyme-linked immunosorbent assay (ELISA) and BAFF with a commercially available ELISA kit in a cohort of patients who developed fatigue syndromes and/or FGIDs after Giardia infection, by comparing them with healthy controls without these conditions.

Results: We did not find significant differences in circulating BAFF, anti-CdtB, or anti-flagellin antibody levels in these patient groups compared to healthy controls. Therefore, our results do not support a role for BAFF, anti-CdtB, or anti-flagellin antibodies as universal biomarkers for IBS or CFS.

Conclusion: BAFF, anti-CdtB, or anti-flagellin antibodies cannot be considered as universal biomarkers for IBS or CFS.

Keywords: B‐cell activating factor; biomarker; chronic fatigue syndrome; cytolethal distending toxin B; flagellin; irritable bowel syndrome; myalgic encephalitis.