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

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.

Perceived food hypersensitivity: a review of 10 years of interdisciplinary research at a reference center.

Perceived food hypersensitivity is a prevalent, but poorly understood condition. In this review article, we summarize narratively recent literature including results of our 10 years' interdisciplinary research program dealing with such patients. The patients (more than 400) included in our studies were all adults referred to a university hospital because of gastrointestinal complaints self-attributed to food hypersensitivity. Despite extensive examinations, food allergy was seldom diagnosed. The majority of the patients fulfilled the diagnostic criteria for irritable bowel syndrome. In addition, most suffered from several extra-intestinal health complaints and had considerably impaired quality of life. However, psychological factors could explain only approximately 10% of the variance in the patients' symptom severity and 90% of the variance thus remained unexplained. Intolerance to low-digestible carbohydrates was a common problem and abdominal symptoms were replicated by carbohydrate ingestion. A considerable number of patients showed evidence of immune activation by analyses of B-cell activating factor, dendritic cells and "IgE-armed" mast cells. Multiple factors such as immune activation, disturbed intestinal fermentation, enteric dysmotility, post-infectious changes and "local" allergy in the gut as well as psychological disturbances may play a role in the pathophysiology of perceived food hypersensitivity. Hence, our results support the view that management of these patients should be interdisciplinary.

Duodenal administered seal oil for patients with subjective food hypersensitivity: an explorative open pilot study.

Short-term duodenal administration of n-3 polyunsaturated fatty acid (PUFA)-rich seal oil may improve gastrointestinal complaints in patients with subjective food hypersensitivity, as well as joint pain in patients with inflammatory bowel disease (IBD). The aim of the present explorative pilot study was to investigate whether 10-day open treatment with seal oil, 10 mL self-administrated via a nasoduodenal tube 3 times daily, could also benefit nongastrointestinal complaints and quality of life (QoL) in patients with subjective food hypersensitivity. Twenty-six patients with subjective food hypersensitivity, of whom 25 had irritable bowel syndrome (IBS), were included in the present study. Before and after treatment and 1 month posttreatment, patients filled in the Ulcer Esophagitis Subjective Symptoms Scale (UESS) and the Gastrointestinal Symptom Rating Scale (GSRS) for gastrointestinal symptoms and subjective health complaints (SHC) inventory for nongastrointestinal symptoms in addition to short form of the Nepean dyspepsia index (SF-NDI) for evaluation of QoL. Compared with baseline, gastrointestinal, as well as nongastrointestinal, complaints and QoL improved significantly, both at end of treatment and 1 month posttreatment. The consistent improvements following seal oil administration warrant further placebo-controlled trials for confirmation of effect.

Direct determination of serotonin in gut lavage fluid by liquid chromatographic ion trap tandem mass spectrometry.

Direct determination of serotonin (5-HT) in gut lavage fluid from patients examined due to various gastrointestinal complaints has been achieved. The method involves addition of 5-methoxytryptamine (5-CH3O-HT) internal standard, centrifugation, filtration and injection of the sample supernatant in a liquid chromatographic system coupled to an ion trap tandem mass detector. Electro-spray in positive mode was used to isolate and fragment the protonated ions [5-HT+H]+ and [5-CH3O-HT+H]+ signals 177 and 191 m/z, respectively. Quantification was carried out by extracting the ion fragment chromatograms at 160 and 174 m/z for 5-HT and 5-CH3O-HT, respectively. The relationship 5-HT/5-CH3O-HT was modelled by using a simultaneous design in order to estimate the optimal amount of internal standard to be added to the samples prior to quantification.