Subjective food hypersensitivity: assessment of enterochromaffin cell markers in blood and gut lavage fluid

Kine Gregersen^1,2, Jørgen Valeur^1,3, Kristine Lillestøl^1,3, Livar Frøyland², Pedro Araujo², Gülen Arslan Lied^1,3, Arnold Berstad^1,3
1Institute of Medicine, University of Bergen, ²National Institute of Nutrition and Seafood Research; ³Department of Medicine, Section for Gastroenterology, Haukeland University Hospital, Bergen, Norway

Background: Food hypersensitivity is commonly suspected, but seldom verified. Patients with subjective food hypersensitivity suffer from both intestinal and extraintestinal health complaints. Abnormalities of the enterochromaffin cells may play a role in the pathogenesis. The aim of this study was to investigate enterochromaffin cell function in patients with subjective food hypersensitivity by measuring serum chromogranin A (CgA) and 5-hydroxytryptamine (5-HT, serotonin) in gut lavage fluid.
Methods: Sixty-nine patients with subjective food hypersensitivity were examined. Twenty-three patients with inflammatory bowel disease and 35 healthy volunteers were included as comparison groups. CgA was measured in serum by enzyme-linked immunosorbent assay. Gut lavage fluid was obtained by administering 2 L of polyethylene glycol solution intraduodenally. The first clear fluid passed per rectum was collected and 5-HT was analyzed by liquid chromatography tandem mass spectrometry.
Results: Serum levels of CgA were significantly lower in patients with subjective food hypersensitivity than in healthy controls (P = 0.04). No differences were found in 5-HT levels in gut lavage fluid between patients with subjective food hypersensitivity and the control groups. There was no correlation between serum CgA and gut lavage 5-HT.
Conclusion: Decreased blood levels of CgA suggest neuroendocrine alterations in patients with subjective food hypersensitivity. However, 5-HT levels in gut lavage fluid were normal.

Keywords: food hypersensitivity, chromogranin A, serotonin, gut lavage fluid, liquid chromatography