[Chronic diarrhoea: when is it celiac disease and when not?] / Chronische Durchfälle: Wann ist es eine Zöliakie und wann nicht?

Patients who come to clinical consultation for chronic diarrhoea (i.e., diarrhoea lasting for more than four weeks) may suffer from a wide range of clinical conditions. The possible diagnoses range from a misunderstanding of what can be considered normal and what pathological in terms of daily bowel movements, to a severe malabsorption syndrome. Since the list of possible causes of chronic diarrhoea can be puzzling, the physician's approach needs to be systematic and structured in order to allow the correct diagnosis and treatment. This article proposes an algorithm for the diagnosis of chronic diarrhoea and discusses in detail the key clinical aspects of celiac disease, which is considered a paradigmatic disease as regards chronic malabsorptive diarrhoea.

Guidelines for best practices in monitoring established coeliac disease in adult patients.

Coeliac disease (CeD) is an immunological disease triggered by the consumption of gluten contained in food in individuals with a genetic predisposition. Diagnosis is based on the presence of small bowel mucosal atrophy and circulating autoantibodies (anti-type 2 transglutaminase antibodies). After diagnosis, patients follow a strict, life-long gluten-free diet. Although the criteria for diagnosis of this disease are well defined, the monitoring phase has been studied less and there is a lack of specific guidelines for this phase. To develop a set of clinical guidelines for CeD monitoring, we followed the Grading of Recommendations Assessment, Development and Evaluation methodology. Statements and recommendations with the level of evidence were developed and approved by the working group, which comprised gastroenterologists, pathologists, dieticians and biostatisticians. The proposed guidelines, endorsed by the North American and European coeliac disease scientific societies, make recommendations for best practices in monitoring patients with CeD based on the available evidence. The evidence level is low for many topics, suggesting that further research in specific aspects of CeD would be valuable. In conclusion, the present guidelines support clinicians in improving CeD treatment and follow-up and highlight novel issues that should be considered in future studies.

Analysis of Circulating Food Antigen-Specific T-Cells in Celiac Disease and Inflammatory Bowel Disease.

To demonstrate and analyze the specific T-cell response following barrier disruption and antigen translocation, circulating food antigen-specific effector T-cells isolated from peripheral blood were analyzed in patients suffering from celiac disease (CeD) as well as inflammatory bowel disease (IBD). We applied the antigen-reactive T-cell enrichment (ARTE) technique allowing for phenotypical and functional flow cytometric analyses of rare nutritional antigen-specific T-cells, including the celiac disease-causing gliadin (gluten). For CeD, patient groups, including treatment-refractory cases, differ significantly from healthy controls. Even symptom-free patients on a gluten-free diet were distinguishable from healthy controls, without being previously challenged with gluten. Moreover, frequency and phenotype of nutritional antigen-specific T-cells of IBD patients directly correlated to the presence of small intestinal inflammation. Specifically, the frequency of antigen specific T-cells as well as pro-inflammatory cytokines was increased in patients with active CeD or Crohn's disease, respectively. These results suggest active small intestinal inflammation as key for the development of a peripheral food antigen-specific T-cell response in Crohn's disease and celiac disease.

Nomenclature and Definition of Atrophic Lesions in Small Bowel Capsule Endoscopy: A Delphi Consensus Statement of the International CApsule endoscopy REsearch (I-CARE) Group.

(1) Background: Villous atrophy is an indication for small bowel capsule endoscopy (SBCE). However, SBCE findings are not described uniformly and atrophic features are sometimes not recognized; (2) Methods: The Delphi technique was employed to reach agreement among a panel of SBCE experts. The nomenclature and definitions of SBCE lesions suggesting the presence of atrophy were decided in a core group of 10 experts. Four images of each lesion were chosen from a large SBCE database and agreement on the correspondence between the picture and the definition was evaluated using the Delphi method in a broadened group of 36 experts. All images corresponded to histologically proven mucosal atrophy; (3) Results: Four types of atrophic lesions were identified: mosaicism, scalloping, folds reduction, and granular mucosa. The core group succeeded in reaching agreement on the nomenclature and the descriptions of these items. Consensus in matching the agreed definitions for the proposed set of images was met for mosaicism (88.9% in the first round), scalloping (97.2% in the first round), and folds reduction (94.4% in the first round), but granular mucosa failed to achieve consensus (75.0% in the third round); (4) Conclusions: Consensus among SBCE experts on atrophic lesions was met for the first time. Mosaicism, scalloping, and folds reduction are the most reliable signs, while the description of granular mucosa remains uncertain.

The combination of clinical parameters and immunophenotyping of intraepithelial lymphocytes allows to assess disease severity in refractory celiac disease.

BACKGROUND: Flow cytometry of intestinal lymphocytes is discussed to be a stronger predictor of enteropathy-associated T-cell lymphoma development in refractory celiac disease than T-cell clonality analysis. AIMS: To investigate possible associations between clinical characteristics of refractory celiac disease patients and aberrant intraepithelial lymphocytes and to evaluate the accuracy of immunophenotyping for the identification of high-risk refractory celiac disease. METHODS: Flow cytometry of isolated lymphocytes from duodenal biopsies of controls and celiac disease patients was performed and results were compared to clinical data. RESULTS: Flow cytometry analysis was performed on 42 controls, 37 non-complicated celiac disease and 30 refractory celiac disease cases with or without T-cell receptor clonality. Elevated aberrant intraepithelial lymphocyte counts were significantly associated with severe malabsorption. A 15% cut-off (aberrant lymphocytes among all lymphocytes) had the best discriminatory ability to identify high-risk patients. However, this technique failed to identify some high-risk cases (sensitivity 63%, specificity 100%). The severity of malabsorption was added to the criteria for high-risk refractory celiac disease, improving the correct patients' allocation (sensitivity 100%, specificity 96%). CONCLUSION: Immunophenotyping of aberrant intraepithelial lymphocytes is a good predictor for high-risk refractory celiac disease. Furthermore, adding the evaluation of malabsorption to the diagnostic assessment of refractory celiac disease optimizes accuracy.

PuraStat in gastrointestinal bleeding: results of a prospective multicentre observational pilot study.

BACKGROUND: A recently developed haemostatic peptide gel for endoscopic application has been introduced to improve the management of gastrointestinal bleeding. The aim of this pilot study was to evaluate the feasibility, safety, efficacy and indication profiles of PuraStat in a clinical setting. METHODS: In this prospective observational multicentre pilot study, patients with acute non-variceal gastrointestinal bleeding (upper and lower) were included. Primary and secondary application of PuraStat was evaluated. Haemoglobin, prothrombin time, platelets and transfusion behaviour were documented before and after haemostasis. The efficacy of PuraStat was assessed during the procedure, at 3 days and 1 week after application. RESULTS: 111 patients with acute gastrointestinal bleeding were recruited into the study. 70 percent (78/111) of the patients had upper gastrointestinal bleeding and 30% (33/111) had lower gastrointestinal bleeding. After primary application of PuraStat, initial haemostatic success was achieved in 94% of patients (74/79, 95% CI 88-99%), and in 75% of the patients when used as a secondary haemostatic product, following failure of established techniques (24/32, 95% CI 59-91%). The therapeutic success rates (absence of rebleeding) after 3 and 7 days were 91% and 87% after primary use, and 87% and 81% in all study patients. Overall rebleeding rate at 30 day follow-up was 16% (18/111). In the 5 patients who finally required surgery (4.5%), PuraStat allowed temporary haemostasis and stabilisation. CONCLUSIONS: PuraStat expanded the therapeutic toolbox available for an effective treatment of gastrointestinal bleeding sources. It could be safely applied and administered without complications as a primary or secondary therapy. PuraStat may additionally serve as a bridge to surgery in order to achieve temporary haemostasis in case of refractory severe bleeding, possibly playing a role in preventing immediate emergency surgery.

Effectiveness of Capsule Endoscopy and Double-Balloon Enteroscopy in Suspected Complicated Celiac Disease.

BACKGROUND & AIMS: Complicated celiac disease (CCD) is a rare but severe condition with a poor prognosis. Guidelines recommend use of capsule endoscopy (CE) to explore the small bowel (SB), followed by a double-balloon enteroscopy (DBE) in selected cases with suspected CCD. Our study aimed to evaluate the diagnostic yield (DY) of CE and DBE in identifying and monitoring CCD. METHODS: Consecutive suspected CCD patients were enrolled prospectively to undergo CE and/or DBE in the presence of: persistent symptoms despite a correct gluten-free diet (GFD), increased anti-transglutaminase antibodies titer, lack of adherence to the GFD, and CCD monitoring. The DY of CE and DBE were calculated. The incidence of neoplastic complications and mortality were assessed. RESULTS: In total, 130 patients (97 women; age, 49 ± 16 y) underwent 151 CEs and 23 DBEs. The DY of CE was 46%. Patients older than age 50 years (at CE examination or at CD diagnosis) with a CD duration shorter than 5 years were at higher risk of positive CE (relative risk, 1.6 and 1.7 in case of enrollement or CD diagnosis after 50 years of age, and 1.5 in case of short CD duration; P < .05) than their counterparts. Up to 40% of SB lesions were unreachable by upper endoscopy. At the end of the diagnostic work-up, 25 patients with premalignant/malignant lesions were identified: 12 type 1 refractory CD (RCD-1), 7 type 2 RCD (RCD-2), and 6 enteropathy-associated T-cell lymphoma (EATL). Six patients died: 2 patients with RCD-2 and 4 patients with EATL. CONCLUSIONS: In case of suspected CCD, CE should be the first-line approach to detect complications and to identify patients deserving DBE. Older and symptomatic patients with suspected CCD deserve a careful evaluation of the SB, especially during the first years after diagnosis.

Results from the German registry for refractory celiac disease.

Refractory celiac disease (RCD) refers to a rare subgroup of patients with celiac disease who show clinical signs of malabsorption despite a gluten-free diet. RCD is divided into an autoimmune phenotype (RCD type I) and pre-lymphoma (RCD type II). To reflect the clinical reality in managing this disease in Germany, a national register was established based on a questionnaire developed specifically for this purpose. Between 2014 and 2020, a total of 53 patients were registered. The diagnosis of RCD was confirmed in 46 cases (87%). This included 27 patients (59%) with RCD type I and 19 patients (41%) with RCD type II. A wide range of diagnostic and therapeutic measures was used. Therapeutically, budesonide was used in 59% of the RCD patients regardless of the subtype. Nutritional therapy was used in only 5 patients (11%). Overall mortality was 26% (12 patients) with a clear dominance in patients with RCD type II (9 patients, 47%). In summary, RCD needs to become a focus of national guidelines to increase awareness, establish standards, and thus enable the treating physician to make the correct diagnosis in a timely manner. Moreover, we concluded that when treating such patients, contacting a specialized center is recommended to ensure sufficient management.

Expression of tricellular tight junction proteins and the paracellular macromolecule barrier are recovered in remission of ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) has a relapsing and remitting pattern, wherein the underlying mechanisms of the relapse might involve an enhanced uptake of luminal antigens which stimulate the immune response. The tricellular tight junction protein, tricellulin, takes charge of preventing paracellular passage of macromolecules. It is characterized by downregulated expression in active UC and its correct localization is regulated by angulins. We thus analyzed the tricellulin and angulin expression as well as intestinal barrier function and aimed to determine the role of tricellulin in the mechanisms of relapse. METHODS: Colon biopsies were collected from controls and UC patients who underwent colonoscopy at the central endoscopy department of Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin. Remission of UC was defined basing on the clinical appearance and a normal Mayo endoscopic subscore. Intestinal barrier function was evaluated by electrophysiological and paracellular flux measurements on biopsies mounted in Ussing chambers. RESULTS: The downregulated tricellulin expression in active UC was recovered in remission UC to control values. Likewise, angulins were in remission UC at the same levels as in controls. Also, the epithelial resistance which was decreased in active UC was restored in remission to the same range as in controls, along with the unaltered paracellular permeabilities for fluorescein and FITC-dextran 4 kDa. CONCLUSIONS: In remission of UC, tricellulin expression level as well as intestinal barrier functions were restored to normal, after they were impaired in active UC. This points toward a re-sealing of the impaired tricellular paracellular pathway and abated uptake of antigens to normal rates in remission of UC.

Double-Balloon Enteroscopy in Detecting Small-Bowel Neuroendocrine Neoplasms: A Single-Center Prospective Study.

BACKGROUND AND AIM: Small-bowel neuroendocrine neoplasm (sbNEN) diagnosis has improved with double-balloon enteroscopy (DBE). DBE efficacy in the detection of sbNENs is unknown. We aimed to report the experience at a single referral center for NENs. METHODS: All consecutive patients with a suspected sbNEN selected for diagnostic DBE were enrolled. RESULTS: Between 2011 and 2016, 25 patients were referred for a suspected sbNEN. In 15/25 patients, a primary NEN was detected outside the small bowel; in 4, NEN was excluded. After extensive workup, 6 patients (4 males, median age 50 years) underwent DBE (3 anterograde, 2 retrograde, and 1 both; median time: 60 min; median insertion 200 cm). DBE was positive in 3 patients: one had an ileal 2-cm NEN G1, one had an ileal 1.3-cm NEN G1, and one had an ileal 1-cm NEN G2, all surgically removed. Of the 3 other patients, one had a metastatic NEN of unknown primary, the other two had small intestinal NENs, both surgically removed (1.6-cm G1 and G2 NEN). DBE showed a sensitivity of 60% and, in absence of false-positive results, a specificity of 100%. Accuracy resulted 67%. No complications were observed. CONCLUSIONS: In line with data from the literature, the present series showed that DBE is a safe and effective procedure in the diagnosis of sbNENs. Further studies are needed to better clarify the diagnostic role of DBE in the neuroendocrine tumor setting and its relationship with other techniques.

Leptin Downregulates Angulin-1 in Active Crohn's Disease via STAT3.

Crohn's disease (CD) has an altered intestinal barrier function, yet the underlying mechanisms remain to be disclosed. The tricellular tight junction protein tricellulin is involved in the maintenance of the paracellular macromolecule barrier and features an unchanged expression level in CD but a shifted localization. As angulins are known to regulate the localization of tricellulin, we hypothesized the involvement of angulins in CD. Using human biopsies, we found angulin-1 was downregulated in active CD compared with both controls and CD in remission. In T84 and Caco-2 monolayers, leptin, a cytokine secreted by fat tissue and affected in CD, decreased angulin-1 expression. This effect was completely blocked by STAT3 inhibitors, Stattic and WP1066, but only partially by JAK2 inhibitor AG490. The effect of leptin was also seen at a functional level as we observed in Caco-2 cells an increased permeability for FITC-dextran 4 kDa indicating an impaired barrier against macromolecule uptake. In conclusion, we were able to show that in active CD angulin-1 expression is downregulated, which leads to increased macromolecule permeability and is inducible by leptin via STAT3. This suggests that angulin-1 and leptin secretion are potential targets for intervention in CD to restore the impaired intestinal barrier.

Efficacy of a High-Iron Dietary Intervention in Women with Celiac Disease and Iron Deficiency without Anemia: A Clinical Trial.

BACKGROUND AND AIM: Iron deficiency without anemia (IDWA) is a common finding in celiac disease (CD) and can also persist in case of good compliance and clinical response to a strict gluten-free diet (GFD). This scenario usually presents in CD women of child-bearing age in whom the imbalance between menstrual iron loss and inadequate iron intake from their diet plays the major role. A recommended approach to this condition is yet to be established. This study aimed to compare, in this subset of patients, the efficacy of a dietary approach consisting of an iron-rich diet against the traditional pharmacological oral-replacement therapy. MATERIAL AND METHODS: Between February and December 2016, consecutive CD female patients of child-bearing age as referred to our outpatient center with evidence of IDWA (ferritin <15 ng/mL or 15-20 ng/L with transferrin saturation <15%) were enrolled. After the completion of a 7-day weighed food intake recording to assess the usual iron dietary intake, the patients were randomized in two arms to receive a 12-week iron-rich diet (iron intake >20 mg/die) versus oral iron supplementation with ferrous sulfate (FS) (105 mg/day). Blood tests and dietary assessments were repeated at the end of treatment. The degree of compliance and tolerability to the treatments were assessed every month by means of specific questionnaires and symptoms evaluation. RESULTS: A total of 22 women were enrolled and divided in the diet group (n = 10, age 37 ± 8 years) and in the FS group (n = 12, age 38 ± 10 years). The food intake records demonstrated an inadequate daily intake of iron in all the enrolled subjects. At the end of the treatments, ferritin levels were higher in the FS group (8.5 (5) versus 34 (30.8), p = 0.002). Compliance and tolerability were similar in both treatment groups (89% versus 87%, p = ns). CONCLUSIONS: These findings did not support any equivalent efficacy of an iron-rich diet compared to a FS supplementation in non-anemic iron-deficient women affected by CD. However, the diet appeared a well-tolerated approach, and adequate dietary instructions could effectively increase the daily iron consumption, suggesting a role in the long-term management of IDWA, especially in patients who do not tolerate pharmacological supplementation.

Efficacy and safety of device-assisted enteroscopy ERCP in liver transplantation: A systematic review and meta-analysis.

BACKGROUND: Enterobiliary anastomoses are the main source of complications after liver transplantation. An endoscopic approach combining device-assisted enteroscopy and ERCP (DAE-ERCP) is technically feasible in postsurgical anatomy. AIMS: This study aimed at assessing the efficacy, feasibility, and safety of DAE-ERCP in liver-transplanted patients (LT) and other subsets (non-LT). METHODS: A systematic review and meta-analysis of studies involving DAE procedures in LT patients (between January 2000 and May 2017) was conducted. The main endpoints were as follows: endoscopic, diagnostic, therapeutic, and overall success rates, complications, and the need for surgery. RESULTS: A total of 155 studies were retrieved, and 6 relevant trials were analyzed. Overall, 132 subjects (72 LT and 60 non-LT) undergoing 257 DAE-ERCP (135 and 122) were included. Complications were rare (4/257), and no deaths occurred. These are the pooled success rates among LT and non-LT patients: 80%-100% and 82%-95% (enteroscopic), 75%-100% and 89%-100% (diagnostic), 67%-100% and 92%-100% (therapeutic), and 60%-100% and 79%-83% (overall results). The requirement for surgery was similar in the two subgroups. CONCLUSION: In managing biliary complications, the high diagnostic and therapeutic success rates of DAE-ERCP combined with its safety and feasibility encourage its application as a first-line approach to transplanted patients.

Is Peer Support in Group Clinics as Effective as Traditional Individual Appointments? The First Study in Patients With Celiac Disease.

INTRODUCTION: Celiac disease (CD) is common, affecting approximately 1% of the population. The cornerstone of management is a gluten-free diet, with dietetic advice being the key to aiding implementation. The aim of the study was to assess group clinics in comparison with traditional individual appointments. METHODS: Patients with a new diagnosis of CD, confirmed histologically, were prospectively recruited over 18 months in Sheffield, United Kingdom. Patients received either a group clinic or traditional one-to-one appointment, led by a dietitian. Quality-of-life questionnaires were completed at baseline, as well as biochemical parameters being recorded. Patients were followed up at 3 months, where adherence scores were assessed as well as biochemical parameters and quality of life questionnaires being completed. RESULTS: Sixty patients with CD were prospectively recruited and received either an individual (n = 30) or group clinic (n = 30). A statistically significant reduction in tissue transglutaminase was noted following group clinics (mean 58.5, SD 43.4 U/mL vs mean 13.2, SD 5.7 U/mL, P < 0.01). No significant differences in baseline and follow-up biochemical parameters between one-to-one and group clinics were noted. At follow-up, there was no statistically significant difference between mean gluten-free diet adherence scores (mean 3.1, SD 0.4 vs mean 3.1, SD 0.7, P = 0.66) between one-to-one and group clinics. DISCUSSION: This first study assessing group clinics in CD demonstrates they are as effective as traditional one-to-one clinics, with the added benefits of peer support and greater efficiency, with an estimated 54% reduction of dietetic resources.

Small-bowel capsule endoscopy in patients with celiac disease, axial versus lateral/panoramic view: Results from a prospective randomized trial.

BACKGROUND AND AIM: Capsule enteroscopy (CE) is recommended in the management of complicated celiac disease (CD). However, published data are derived from axial-view capsule systems. No data are available on the use of lateral/panoramic view capsules. This study aimed at evaluating the diagnostic yield and efficacy of the lateral/panoramic versus the axial view capsule system in CD. METHODS: Consecutive CD patients were enrolled in a prospective monocentric study. Each patient ingested an axial (PillCam SB3) and a lateral/panoramic (CapsoCam Plus) view capsule with a 3-h interval in a randomized order. Two experts blindly evaluated the CE carried out. A third expert reviewed the videos in cases of discordance. RESULTS: Twenty-five CD patients were enrolled (four males, age at CE 51.2 ± 16.6 years, age at CD diagnosis 41.7 ± 20.6, years on a gluten-free diet [GFD] 9.6 ± 9.4). Indications at CE were refractory CD in nine cases, non-responsiveness to GFD in 10 and GFD non-compliance in six. A positive finding was evidenced in 15 (60%) and 13 (52%) cases by CapsoCam and PillCam respectively (not significant). Atrophy was detected by both capsules. Considering the percentage of the small-bowel mucosa presenting atrophy signs, mean values were 22% ± 35 and 20% ± 29 for lateral/panoramic and axial systems, respectively (not significant). Compared to duodenal histology, PillCam correctly identified 80% of patients with SB atrophy, whereas CapsoCam identified 73% of cases. CONCLUSIONS: Lateral/panoramic view CE is effective in the detection of small-bowel atrophy in CD and presents good sensitivity and specificity when compared to histology.

Celiac Disease Monocytes Induce a Barrier Defect in Intestinal Epithelial Cells.

Intestinal epithelial barrier function in celiac disease (CeD) patients is altered. However, the mechanism underlying this effect is not fully understood. The aim of the current study was to evaluate the role of monocytes in eliciting the epithelial barrier defect in CeD. For this purpose, human monocytes were isolated from peripheral blood mononuclear cells (PBMCs) from active and inactive CeD patients and healthy controls. PBMCs were sorted for expression of CD14 and co-cultured with intestinal epithelial cells (IECs, Caco2BBe). Barrier function, as well as tight junctional alterations, were determined. Monocytes were characterized by profiling of cytokines and surface marker expression. Transepithelial resistance was found to be decreased only in IECs that had been exposed to celiac monocytes. In line with this, tight junctional alterations were found by confocal laser scanning microscopy and Western blotting of ZO-1, occludin, and claudin-5. Analysis of cytokine concentrations in monocyte supernatants revealed higher expression of interleukin-6 and MCP-1 in celiac monocytes. However, surface marker expression, as analyzed by FACS analysis after immunostaining, did not reveal significant alterations in celiac monocytes. In conclusion, CeD peripheral monocytes reveal an intrinsically elevated pro-inflammatory cytokine pattern that is associated with the potential of peripheral monocytes to affect barrier function by altering TJ composition.

Intestinal Barrier Function in Gluten-Related Disorders.

Gluten-related disorders include distinct disease entities, namely celiac disease, wheat-associated allergy and non-celiac gluten/wheat sensitivity. Despite having in common the contact of the gastrointestinal mucosa with components of wheat and other cereals as a causative factor, these clinical entities have distinct pathophysiological pathways. In celiac disease, a T-cell mediate immune reaction triggered by gluten ingestion is central in the pathogenesis of the enteropathy, while wheat allergy develops as a rapid immunoglobulin E- or non-immunoglobulin E-mediated immune response. In non-celiac wheat sensitivity, classical adaptive immune responses are not involved. Instead, recent research has revealed that an innate immune response to a yet-to-be-defined antigen, as well as the gut microbiota, are pivotal in the development in this disorder. Although impairment of the epithelial barrier has been described in all three clinical conditions, its role as a potential pathogenetic co-factor, specifically in celiac disease and non-celiac wheat sensitivity, is still a matter of investigation. This article gives a short overview of the mucosal barrier of the small intestine, summarizes the aspects of barrier dysfunction observed in all three gluten-related disorders and reviews literature data in favor of a primary involvement of the epithelial barrier in the development of celiac disease and non-celiac wheat sensitivity.

Correction: Roncoroni, L. et al. A Low FODMAP Gluten-Free Diet Improves Functional Gastrointestinal Disorders and Overall Mental Health of Celiac Disease Patients: A Randomized Controlled Trial. Nutrients 2018, 10, 1023.

The authors have requested that the following changes be made to their paper [...].

Exposure to Different Amounts of Dietary Gluten in Patients with Non-Celiac Gluten Sensitivity (NCGS): An Exploratory Study.

It is unclear whether patients with non-celiac gluten sensitivity (NCGS) can tolerate gluten. We have evaluated the changes of both gastrointestinal symptoms and quality of life for NCGS patients after the re-introduction of dietary gluten. Twenty-two NCGS patients reporting functional gastroenterological symptoms and on gluten-free diet (GFD) for the previous three weeks were exposed to incremental gluten-containing diets. Three groups were compared at baseline (immediately after 3-weeks on GFD) and immediately after the return of symptomatology: (i) a group tolerating a low-gluten diet (3.5 g gluten/day, week 1, n = 8), (ii) a group tolerating a mid-gluten diet (8 g gluten/day, week 2, n = 6), and (iii) a group tolerating a high-gluten diet (13 g gluten/day, week 3, n = 8). Their gastrointestinal symptoms and quality of life were assessed at baseline and post-intervention. The most common symptoms were: constipation (46%), abdominal pain (50%) and dyspepsia (38%). A decrease in several short form health survey (SF-36) sub-scores (all p < 0.03) after gluten re-introduction was only observed in the group tolerating the low-gluten diet; the same group showed a lower post-intervention role-emotional SF-36 score (p = 0.01). Most gastrointestinal symptoms remained similar after gluten re-introduction. However, a decrease in the general perception of well-being was only found after gluten re-introduction in the group tolerating a low-gluten diet (p = 0.01); the same was true when comparing the post-intervention general well-being perception among the three groups (p = 0.050). In conclusion, dissimilar responses from patients with NCGS were observed after the re-introduction of gluten, with gluten at a low dosage affecting the quality of life and general well-being of a group of patients, whereas others tolerate even higher doses of dietary gluten.

Gliadin effect on the oxidative balance and DNA damage: An in-vitro, ex-vivo study.

BACKGROUND: Gliadins are involved in gluten-related disorders and are responsible for the alteration of the cellular redox balance. It is not clear if the gliadin-related oxidative stress can induce DNA damage in enterocytes. AIM: To investigate any possible genotoxicity caused by gliadin and to assess its relationship with oxidative stress in vitro and ex vivo. METHODS: Caco-2 cells were exposed for 6-12-24 h to increasing concentrations (250 µg/mL-1000 µg/mL) of digested gliadin. We investigated: cytotoxicity, oxidative balance (reactive oxygen species, ROS), DNA damage (comet assay and γ-H2AX detection), transglutaminase type 2 (TG2) activity and annexin V expression. H2AX and 8-OHG immunohistochemistry has been evaluated on duodenal biopsies of celiac subjects and controls. RESULTS: Gliadin induced a significant increase (+50%) of ROS after 12 h of exposition starting with a 500 µg/mL dose of gliadin. Comet assay and γ-H2AX demonstrated DNA damage, evident at the gliadin concentration of 500 µg/mL after 24 h. TG2 activity increased in chromatin and cytoskeleton cellular compartments at different gliadin doses (250/500/1000 µg/mL). The γ-H2AX and 8-OHG immunohistochemistry was altered in the duodenal biopsies of celiac patients. CONCLUSIONS: Gliadin induces cellular oxidative stress, DNA damage and pro-apoptotic stimulation in Caco-2 cells and in the duodenal mucosa of celiac patients.