Innate and adaptive immunity in self-reported nonceliac gluten sensitivity versus celiac disease.

BACKGROUND: Immune mechanisms have been implicated in nonceliac gluten sensitivity (NCGS), a condition characterized by intestinal and/or extraintestinal symptoms caused by the ingestion of gluten in non-celiac/non-wheat allergic individuals. AIMS: We investigated innate and adaptive immunity in self-reported NCGS versus celiac disease (CD). METHODS: In the supernatants of ex vivo-cultured duodenal biopsies from 14 self-reported NCGS patients, 9 untreated and 10 treated CD patients, and 12 controls we detected innate cytokines - interleukin (IL)-15, tumor necrosis factor-α, IL-1ß, IL-6, IL-12p70, IL-23, IL-27, IL-32α, thymic stromal lymphopoietin (TSLP), IFN-α-, adaptive cytokines - interferon (IFN)-γ, IL-17A, IL-4, IL-5, IL-10, IL-13-, chemokines - IL-8, CCL1, CCL2, CCL3, CCL4, CCL5, CXCL1, CXCL10-, granulocyte colony stimulating factor (G-CSF) and granulocyte-macrophage colony stimulating factor (GM-CSF). RESULTS: Mucosal innate and adaptive cytokines, chemokines and growth factors did not differ between self-reported NCGS, treated CD and controls. On the contrary, IL-6, IL-15, IL-27, IFN-α, IFN-γ, IL-17A, IL-23, G-CSF, GM-CSF, IL-8, CCL1 and CCL4 were significantly higher in untreated CD than in self-reported NCGS, treated CD and controls, while TSLP was significantly lower in untreated CD than in self-reported NCGS, treated CD and controls. CONCLUSION: In our hands, patients with self-reported NCGS showed no abnormalities of the mucosal immune response.

Small Amounts of Gluten in Subjects With Suspected Nonceliac Gluten Sensitivity: A Randomized, Double-Blind, Placebo-Controlled, Cross-Over Trial.

BACKGROUND & AIMS: There is debate over the existence of nonceliac gluten sensitivity (NCGS) intestinal and extraintestinal symptoms in response to ingestion of gluten-containing foods by people without celiac disease or wheat allergy. We performed a randomized, double-blind, placebo-controlled, cross-over trial to determine the effects of administration of low doses of gluten to subjects with suspected NCGS. METHODS: We enrolled 61 adults without celiac disease or a wheat allergy who believed ingestion of gluten-containing food to be the cause of their intestinal and extraintestinal symptoms. Participants were assigned randomly to groups given either 4.375 g/day gluten or rice starch (placebo) for 1 week, each via gastrosoluble capsules. After a 1-week gluten-free diet, participants crossed over to the other group. The primary outcome was the change in overall (intestinal and extraintestinal) symptoms, determined by established scoring systems, between gluten and placebo intake. A secondary outcome was the change in individual symptom scores between gluten vs placebo. RESULTS: According to the per-protocol analysis of data from the 59 patients who completed the trial, intake of gluten significantly increased overall symptoms compared with placebo (P = .034). Abdominal bloating (P = .040) and pain (P = .047), among the intestinal symptoms, and foggy mind (P = .019), depression (P = .020), and aphthous stomatitis (P = .025), among the extraintestinal symptoms, were significantly more severe when subjects received gluten than placebo. CONCLUSIONS: In a cross-over trial of subjects with suspected NCGS, the severity of overall symptoms increased significantly during 1 week of intake of small amounts of gluten, compared with placebo. Clinical trial no: ISRCTN72857280.

Increase in neuroendocrine cells in the duodenal mucosa of patients with refractory celiac disease.

OBJECTIVES: Several immune-mediated gastrointestinal disorders, including celiac disease (CD), are associated with neuroendocrine cell hyperplasia. However, neuroendocrine cells have never been explored in refractory CD (RCD). METHODS: Serial duodenal sections from 17 patients with RCD (6 type 1 and 11 type 2), 16 uncomplicated CD patients before and after gluten-free diet, 14 patients with potential CD, 27 patients with non-CD villous atrophy, i.e., common variable immunodeficiency (n=12), Whipple's disease (n=10) and giardiasis (n=5), and 16 healthy subjects were processed for the immunohistochemical detection of chromogranin A (CgA), serotonin, and somatostatin. Mucosal tryptophan hydroxylase (TpH)-1 and serotonin-selective reuptake transporter (SERT) transcripts were measured by quantitative reverse transcription-PCR. Serum CgA and 24-h urine 5-hydroxyindoleacetic acid (5-HIAA) were assessed. Biopsies from treated CD patients were cultured with serotonin or peptic tryptic digest of gliadin (PT-gliadin), and interferon (IFN)-γ was detected by ELISA in culture supernatants. RESULTS: Epithelial cells positive for CgA and serotonin, but not somatostatin, were significantly increased in RCD. Raised mucosal transcripts of TpH-1, but not SERT, were found in RCD. On biopsies from treated CD patients, serotonin upregulated IFN-γ production at levels comparable to those induced by PT-gliadin. Serum CgA, but not urine 5-HIAA, was increased in RCD. No significant difference was found between RCD type 1 and type 2 in terms of neuroendocrine cells, mucosal TpH-1 transcripts, and serum CgA. CONCLUSIONS: Serotonin-producing neuroendocrine cells are increased in RCD mucosa. IFN-γ upregulation induced by serotonin suggests that this monoamine may have a role in sustaining the local inflammatory response in CD.