A Look Into the Future: Are We Ready for an Approved Therapy in Celiac Disease?

As it appears that we are currently at the cusp of an era in which drugs that are new, re-purposed, or "supplements" will be introduced to the management of celiac disease, we need to reflect on whether the framework is set for celiac disease to be treated increasingly with pharmaceuticals as well as diet. This refers to reflecting on the rigor of current diagnostic practices; the limitations of the current standard of care, which is a gluten-free diet; and that we lack objective markers of disease severity. Investigating these issues will help us to identify gaps in technology and practices that could be critical for selecting patients with a well-defined need for an improved or alternative treatment. Both aspects, circumscribed limitations of the gluten-free diet and diagnostics helping to define celiac disease target groups, together with the guiding requirements by the responsible regulatory authorities, will contribute to defining the subgroups of patients with confirmed celiac disease eligible for distinct pharmacologic strategies. Because many patients with celiac disease are diagnosed in childhood, these aspects need to be differentially discussed for the pediatric setting. In this perspective, we aimed to describe these contextual issues and then looked ahead to the future. What might be the major challenges in celiac disease clinics in the coming years once drugs are an option alongside diet? And what will be the future objectives for researchers who further decipher the mucosal immunology of celiac disease? Speculating on the answers to these questions is as stimulating as it is fascinating to be part of this turning point.

A Randomized Trial of a Transglutaminase 2 Inhibitor for Celiac Disease.

BACKGROUND: In celiac disease, small intestinal transglutaminase 2 causes deamidation of glutamine residues in gluten peptides, which enhances stimulation of T cells and leads to mucosal injury. Inhibition of transglutaminase 2 is a potential treatment for celiac disease. METHODS: In a proof-of-concept trial, we assessed the efficacy and safety of a 6-week treatment with ZED1227, a selective oral transglutaminase 2 inhibitor, at three dose levels as compared with placebo, in adults with well-controlled celiac disease who underwent a daily gluten challenge. The primary end point was the attenuation of gluten-induced mucosal damage, as measured by the ratio of villus height to crypt depth. Secondary end points included intraepithelial lymphocyte density, the Celiac Symptom Index score, and the Celiac Disease Questionnaire score (for assessment of health-related quality of life). RESULTS: Of the 41 patients assigned to the 10-mg ZED1227 group, the 41 assigned to the 50-mg group, the 41 assigned to the 100-mg group, and the 40 assigned to the placebo group, 35, 39, 38, and 30 patients, respectively, had adequate duodenal-biopsy samples for the assessment of the primary end point. Treatment with ZED1227 at all three dose levels attenuated gluten-induced duodenal mucosal injury. The estimated difference from placebo in the change in the mean ratio of villus height to crypt depth from baseline to week 6 was 0.44 (95% confidence interval [CI], 0.15 to 0.73) in the 10-mg group (P = 0.001), 0.49 (95% CI, 0.20 to 0.77) in the 50-mg group (P<0.001), and 0.48 (95% CI, 0.20 to 0.77) in the 100-mg group (P<0.001). The estimated differences from placebo in the change in intraepithelial lymphocyte density were -2.7 cells per 100 epithelial cells (95% CI, -7.6 to 2.2) in the 10-mg group, -4.2 cells per 100 epithelial cells (95% CI, -8.9 to 0.6) in the 50-mg group, and -9.6 cells per 100 epithelial cells (95% CI, -14.4 to -4.8) in the 100-mg group. Use of the 100-mg dose may have improved symptom and quality-of-life scores. The most common adverse events, the incidences of which were similar across all groups, were headache, nausea, diarrhea, vomiting, and abdominal pain. Rash developed in 3 of 40 patients (8%) in the 100-mg group. CONCLUSIONS: In this preliminary trial, treatment with ZED1227 attenuated gluten-induced duodenal mucosal damage in patients with celiac disease. (Funded by Dr. Falk Pharma; CEC-3 EudraCT number, 2017-002241-30.).

Enduring Clinical Remission in Refractory Celiac Disease Type II with Tofacitinib: An Open-Label Clinical Study.

Refractory celiac disease type 2 (RCDII) is a rare condition with high mortality because of a lack of effective treatment strategies. RCDII is caused by clonal expansion of intraepithelial lymphocytes (IELs). Gain-of-function JAK1 mutations are frequently found in these cells.1,2 In a previous in vitro study,3 we demonstrated the potential of tofacitinib, a small-molecule JAK1/JAK3 inhibitor, to control activity of the aberrant IEL population. Here, we report on an open-label prospective pilot study with tofacitinib in patients with therapy-refractory RCDII (EudraCT 2018-001678-10; Dutch Trial Registry [LTR] NL7313). Between November 2019 and February 2022, 4 patients with an established diagnosis of RCDII4 who had failed previous therapies were treated in the Netherlands with tofacitinib 10 mg twice-daily for 12 weeks (Methods; Supporting Documents). Two patients in Germany who fulfilled the inclusion criteria received similar treatment outside this protocol.

Selective Uptake Into Inflamed Human Intestinal Tissue and Immune Cell Targeting by Wormlike Polymer Micelles.

Inflammatory bowel disease (IBD) has become a globally prevalent chronic disease with no causal therapeutic options. Targeted drug delivery systems with selectivity for inflamed areas in the gastrointestinal tract promise to reduce severe drug-related side effects. By creating three distinct nanostructures (vesicles, spherical, and wormlike micelles) from the same amphiphilic block copolymer poly(butyl acrylate)-block-poly(ethylene oxide) (PBA-b-PEO), the effect of nanoparticle shape on human mucosal penetration is systematically identified. An Ussing chamber technique is established to perform the ex vivo experiments on human colonic biopsies, demonstrating that the shape of polymeric nanostructures represents a rarely addressed key to tissue selectivity required for efficient IBD treatment. Wormlike micelles specifically enter inflamed mucosa from patients with IBD, but no significant uptake is observed in healthy tissue. Spheres (≈25 nm) and vesicles (≈120 nm) enter either both normal and inflamed tissue types or do not penetrate any tissue. According to quantitative image analysis, the wormlike nanoparticles localize mainly within immune cells, facilitating specific targeting, which is crucial for further increasing the efficacy of IBD treatment. These findings therefore demonstrate the untapped potential of wormlike nanoparticles not only to selectively target the inflamed human mucosa, but also to target key pro-inflammatory cells.

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.

Uptake of Tropheryma whipplei by Intestinal Epithelia.

BACKGROUND: Tropheryma whipplei (TW) can cause different pathologies, e.g., Whipple's disease and transient gastroenteritis. The mechanism by which the bacteria pass the intestinal epithelial barrier, and the mechanism of TW-induced gastroenteritis are currently unknown. METHODS: Using ex vivo disease models comprising human duodenal mucosa exposed to TW in Ussing chambers, various intestinal epithelial cell (IEC) cultures exposed to TW and a macrophage/IEC coculture model served to characterize endocytic uptake mechanisms and barrier function. RESULTS: TW exposed ex vivo to human small intestinal mucosae is capable of autonomously entering IECs, thereby invading the mucosa. Using dominant-negative mutants, TW uptake was shown to be dynamin- and caveolin-dependent but independent of clathrin-mediated endocytosis. Complementary inhibitor experiments suggested a role for the activation of the Ras/Rac1 pathway and actin polymerization. TW-invaded IECs underwent apoptosis, thereby causing an epithelial barrier defect, and were subsequently subject to phagocytosis by macrophages. CONCLUSIONS: TW enters epithelia via an actin-, dynamin-, caveolin-, and Ras-Rac1-dependent endocytosis mechanism and consecutively causes IEC apoptosis primarily in IECs invaded by multiple TW bacteria. This results in a barrier leak. Moreover, we propose that TW-packed IECs can be subject to phagocytic uptake by macrophages, thereby opening a potential entry point of TW into intestinal macrophages.

Proteolytic Activity of the Paracaspase MALT1 Is Involved in Epithelial Restitution and Mucosal Healing.

The paracaspase MALT1 is a crucial regulator of immune responses in various cellular contexts. Recently, there is increasing evidence suggesting that MALT1 might represent a novel key player in mucosal inflammation. However, the molecular mechanisms underlying this process and the targeted cell population remain unclear. In this study, we investigate the role of MALT1 proteolytic activity in the context of mucosal inflammation. We demonstrate a significant enrichment of MALT1 gene and protein expression in colonic epithelial cells of UC patients, as well as in the context of experimental colitis. Mechanistically we demonstrate that MALT1 protease function inhibits ferroptosis, a form of iron-dependent cell death, upstream of NF-κB signaling, which can promote inflammation and tissue damage in IBD. We further show that MALT1 activity contributes to STAT3 signaling, which is essential for the regeneration of the intestinal epithelium after injury. In summary, our data strongly suggests that the protease function of MALT1 plays a critical role in the regulation of immune and inflammatory responses, as well as mucosal healing. Understanding the mechanisms by which MALT1 protease function regulates these processes may offer novel therapeutic targets for the treatment of IBD and other inflammatory diseases.

Prospective, double-blind diagnostic multicentre study of confocal laser endomicroscopy for wheat sensitivity in patients with irritable bowel syndrome.

OBJECTIVE: A considerable proportion of patients with irritable bowel syndrome (IBS) may be wheat-sensitive and respond to a gluten-free diet (GFD) although they do not have coeliac disease. However, a diagnostic test for wheat sensitivity (WS) is missing. Our study evaluated the diagnostic accuracy (sensitivity and specificity) of confocal laser endomicroscopy (CLE) for the identification of WS as primary outcome. DESIGN: In this prospective, double-blind diagnostic study 147 non-coeliac patients fulfilling the Rome III criteria for IBS were tested by CLE for duodenal changes after wheat (index test), soy, yeast or milk exposure. Patients with IBS responding to 2 months of GFD were classified as having WS (reference test) using response criteria recommended by regulatory bodies for pharmaceutical trials of patients with IBS. After 2 months, CLE results were unblinded and patients were advised to exclude those food components that had led to a positive CLE reaction. The clinical response was assessed at follow-up after 6 and 12 months. RESULTS: Of 130 patients who completed the study per protocol, 74 (56.9%) responded to GFD and were classified as WS after 2 months, and 38 of these 74 patients were correctly identified by CLE (sensitivity 51.4%; 97.5% CI: 38.7% to 63.9%). A total of 38 of 56 patients without WS were correctly identified by CLE (specificity 67.9%; 97.5% CI: 52.9% to 79.9%). At 6 months follow-up, CLE correctly identified 49 of 59 food-sensitive patients (sensitivity 83.1%; 97.5% CI: 69.9% to 91.3%) but specificity was only 32% (97.5% CI: 15.7% to 54.3%). CONCLUSION: In light of the high proportion of patients with IBS responding to GFD, the diagnostic accuracy of CLE is too low to recommend widespread use of this invasive procedure. TRAIL REGISTRATION NUMBER: This study was registered as clinical trial in the German Registry for Clinical Studies (DRKS00010123).

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.

S2k Guideline for the diagnosis and treatment of mucous membrane pemphigoid.

Mucous membrane pemphigoid (MMP) is a pemphigoid disease with predominant mucous membrane involvement. It mainly affects the mucous membranes of the mouth, eyes, nose and pharynx, but also the larynx, trachea, esophagus, genital and perianal regions. The manifestation of the disease covers a wide spectrum from gingival erythema and single oral lesions to severe tracheal strictures that obstruct breathing and conjunctival scarring with marked visual impairment and, not infrequently, blindness. In addition to a clinical picture of predominant mucosal involvement, diagnosis is based on direct immunofluorescence of a peri-lesional biopsy and serology. The main target antigen is BP180 (collagen XVII), and reactivity with laminin 332 is associated with malignancy in approximately 25 % of MMP patients. The treatment of MMP is challenging. On the one hand, due to the involvement of different mucous membranes, good interdisciplinary cooperation is required; on the other hand, due to the rarity of the disease, no randomized controlled clinical trials are available. The aim of this guideline is to present the clinical picture, including severity and scoring systems, and to give guidance for diagnosing and treating this complex disease. In MMP, interdisciplinary cooperation plays an essential role as well as the prompt diagnosis and initiation of adequate therapy in order to avoid irreversible damage to the mucous membranes with serious complications.

Level of Tumor Necrosis Factor Production by Stimulated Blood Mononuclear Cells Can Be Used to Predict Response of Patients With Inflammatory Bowel Diseases to Infliximab.

BACKGROUND & AIMS: A substantial proportion patients with inflammatory bowel disease (IBD) have a primary non-response to infliximab; markers are needed to identify patients most likely to respond to treatment. We investigated whether production of tumor necrosis factor (TNF) by peripheral blood mononuclear cells (PBMCs) can be used as a marker to predict response. METHODS: We performed a prospective study of 41 adults with IBD (mean age, 38 years; 21 male; 21 with Crohn's disease and 20 with ulcerative colitis) not treated with a biologic agent within the past 6 months; patients were given their first infusion of infliximab at a hospital or clinic in Berlin, Germany. We collected data on clinical scores, levels of C-reactive protein, and ultrasound results (Limberg scores) at baseline (before the first infusion) and after 6 weeks (3rd infliximab infusion). PMBCs were obtained from patients at baseline and 10 healthy individuals (controls) and incubated with lipopolysaccharide. We measured production of cytokines (TNF, interleukin 1 [IL1], IL6, IL8, IL10, IL12p70, and IL22) by ELISA and performed cytometric bead array and flow cytometry analyses. The primary endpoint was clinical response (decrease in Harvey Bradshaw Index scores of 2 or more or decrease in partial Mayo scores of 3 or more at week 6) in patients with PBMCs that produced high vs low levels of TNF. RESULTS: Responders had a shorter median disease duration (P = .018) and higher median Limberg score (P = .021), than nonresponders. Baseline PBMCs from responders produced significantly more TNF (P = .049) and IL6 (P = .028) than from nonresponders; a level of 500 pg/ml TNF identified responders with 82% sensitivity and 78% specificity. In patients with Crohn's disease, this cutoff value (500 pg/ml TNF) identified responders with 100% sensitivity and 82% specificity; TNF levels above this level were independently associated with response to infliximab in multivariate analysis (odds ratio, 16.2; 95% CI, 1.8-148.7; P = .014). The percentage of TNF-positive cells was higher among CD14+ monocytes than lymphocytes after stimulation. CONCLUSIONS: Production of a high level of TNF by PBMCs (specifically CD14+ cells) from patients with IBD can identify those most likely to have a clinical response to infliximab therapy. In patients with Crohn's disease, a cutoff value of 500 pg/ml TNF identified responders with 100% sensitivity and 82% specificity.

Human biomonitoring (HBM)-II values for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) - Description, derivation and discussion.

For evaluation of internal exposure to harmful substances, the Human Biomonitoring Commission of the German Environment Agency (HBM Commission) develops toxicologically justified assessment values (HBM-I and HBM-II). The HBM-I value corresponds to the concentration of a compound in human biological material below which no adverse health effects are expected to occur. Consequently, no action is required when the HBM-I value is not exceeded (HBM-Commission, 1996). In 2016, the HBM Commission developed HBM-I values of 2 ng PFOA/mL and 5 ng PFOS/mL in blood serum or plasma, respectively. A detailed delineation of supporting arguments was published in April 2018 (HBM-Commission, 2018). In contrast to the HBM-I, the HBM-II value corresponds to the concentration in human biological material which, when exceeded, may lead to health impairment which is considered as relevant to exposed individuals (HBM-Commission, 1996, HBM-Commission, 2014). HBM-II VALUES FOR PFOA AND PFOS: On September 17, 2019, the HBM Commission of the German Environment Agency established the following HBM-II values: Women at child-bearing age: 5 ng PFOA/mL blood plasma; 10 ng PFOS/mL blood plasma; All other population groups: 10 ng PFOA/mL blood plasma; 20 ng PFOS/mL blood plasma.

Human Biomonitoring (HBM)-I values for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) - Description, derivation and discussion.

In 2016, the German Human Biomonitoring Commission (HBM-C) published a statement on its decision to develop HBM-I values for Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) (Bundesgesundheitsbl 2016, 59:1364 DOI 10.1007/s00103-016-2437-1). The HBM-I value corresponds to the concentration of a substance in a human biological material below which no adverse health effects are expected, according to current knowledge and assessment by the HBM-C, and, consequently, there is no need for action. Evidence for associations between PFOA- and PFOS-body burden and health outcomes was found for fertility and pregnancy, weights of newborns at birth, lipid metabolism, immunity, sex hormones and age at puberty/menarche, thyroid hormones, onset of menopause as well as uric acid metabolism. Significant contrasts were reported for human blood plasma concentrations between 1 and 10 ng PFOA/mL, and 1-15 ng PFOS/mL, respectively. Within the reported ranges, the HBM-C has decided to set the HBM-I-values at 2 ng PFOA/mL and 5 ng PFOS/mL blood plasma. The underlying pathomechanisms do not appear to be sufficiently clarified to provide an unambiguous explanation of the effects observed. Consistency of toxicological and epidemiological data has been considered. The available data do not indicate an unequivocal proof of a genotoxicity of PFOA and PFOS.

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.

Low Sensitivity of Simtomax Point of Care Test in Detection of Celiac Disease in a Prospective Multicenter Study.

BACKGROUND & AIMS: Point of care tests (POCTs) might be used to identify patients with undiagnosed celiac disease who require further evaluation. We performed a large multicenter study to determine the performance of a POCT for celiac disease and assessed celiac disease prevalence in endoscopy centers. METHODS: We performed a prospective study of 1055 patients (888 adults; median age, 48 yrs and 167 children; median age, 10 yrs) referred to 8 endoscopy centers in Germany, for various indications, from January 2016 through June 2017. Patients were tested for celiac disease using Simtomax, which detects immunoglobulin (Ig)A and IgG antibodies against deamidated gliadin peptides (DGP). Results were compared with findings from histologic analyses of duodenal biopsies (reference standard). The primary aim was to determine the accuracy of this POCT for the detection of celiac disease, to identify candidates for duodenal biopsy. A secondary aim was to determine the prevalence of celiac disease in adult and pediatric populations referred for outpatient endoscopic evaluation. RESULTS: The overall prevalence of celiac disease was 4.1%. The POCT identified individuals with celiac disease with 79% sensitivity (95% CI, 64%-89%) and 94% specificity (95% CI, 93%-96%). Positive and negative predictive values were 37% and 99%. When we analyzed the adult and pediatric populations separately, we found the test to identify adults with celiac disease (prevalence 1.2%) with 100% sensitivity and 95% specificity. In the pediatric population (celiac disease prevalence 19.6%), the test produced false-negative results for 9 cases; the test therefore identified children with celiac disease with 72% sensitivity (95% CI 53%-86%). Analyses of serologic data revealed significantly lower DGP titers in the false-negative vs the true-positive group. CONCLUSIONS: In a study of more than 1000 adults and children, we found the Simtomax POCT to detect celiac disease with lower overall levels of sensitivity than expected. Although the test identifies adults with celiac disease with high levels of sensitivity and specificity, the prevalence of celiac disease was as low as 1.2% among adults. The test's lack of sensitivity might be due to the low intensity of the POCT bands and was associated with low serum DGP titers. Study ID no: DRKS00012499.

GRHL2 Is Required for Collecting Duct Epithelial Barrier Function and Renal Osmoregulation.

Collecting ducts make up the distal-most tubular segments of the kidney, extending from the cortex, where they connect to the nephron proper, into the medulla, where they release urine into the renal pelvis. During water deprivation, body water preservation is ensured by the selective transepithelial reabsorption of water into the hypertonic medullary interstitium mediated by collecting ducts. The collecting duct epithelium forms tight junctions composed of barrier-enforcing claudins and exhibits a higher transepithelial resistance than other segments of the renal tubule exhibit. However, the functional relevance of this strong collecting duct epithelial barrier is unresolved. Here, we report that collecting duct-specific deletion of an epithelial transcription factor, grainyhead-like 2 (GRHL2), in mice led to reduced expression of tight junction-associated barrier components, reduced collecting duct transepithelial resistance, and defective renal medullary accumulation of sodium and other osmolytes. In vitro, Grhl2-deficient collecting duct cells displayed increased paracellular flux of sodium, chloride, and urea. Consistent with these effects, Grhl2-deficient mice had diabetes insipidus, produced dilute urine, and failed to adequately concentrate their urine after water restriction, resulting in susceptibility to prerenal azotemia. These data indicate a direct functional link between collecting duct epithelial barrier characteristics, which appear to prevent leakage of interstitial osmolytes into urine, and body water homeostasis.

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.

T-cell repertoires in refractory coeliac disease.

OBJECTIVE: Refractory coeliac disease (RCD) is a potentially hazardous complication of coeliac disease (CD). In contrast to RCD type I, RCD type II is a precursor entity of enteropathy-associated T-cell lymphoma (EATL), which is associated with clonally expanding T-cells that are also found in the sequentially developing EATL. Using high-throughput sequencing (HTS), we aimed to establish the small-intestinal T-cell repertoire (TCR) in CD and RCD to unravel the role of distinct T-cell clonotypes in RCD pathogenesis. DESIGN: DNA extracted from duodenal mucosa specimens of controls (n=9), active coeliacs (n=10), coeliacs on a gluten-free diet (n=9), RCD type I (n=8), RCD type II (n=8) and unclassified Marsh I cases (n=3) collected from 2002 to 2013 was examined by TCRß-complementarity-determining regions 3 (CDR3) multiplex PCR followed by HTS of the amplicons. RESULTS: On average, 106 sequence reads per sample were generated consisting of up to 900 individual TCRß rearrangements. In RCD type II, the most frequent clonotypes (ie, sequence reads with identical CDR3) represent in average 42.6% of all TCRß rearrangements, which was significantly higher than in controls (6.8%; p<0.01) or RCD type I (6.7%; p<0.01). Repeat endoscopies in individual patients revealed stability of clonotypes for up to several years without clinical symptoms of EATL. Dominant clonotypes identified in individual patients with RCD type II were unique and not related between patients. CD-associated, gliadin-dependent CDR3 motifs were only detectable at low frequencies. CONCLUSIONS: TCRß-HTS analysis unravels the TCR in CD and allows detailed analysis of individual TCRß rearrangements. Dominant TCRß sequences identified in patients with RCD type II are unique and not homologous to known gliadin-specific TCR sequences, supporting the assumption that these clonal T-cells expand independent of gluten stimulation.

Synthesis and biochemical evaluation of two novel N-hydroxyalkylated cyclosporin A analogs.

The cyclic undecapeptide cyclosporin A (CsA) is a widely used immunosuppressive agent. Its immunosuppressive properties arise from strong binding to cyclophilins (Cyp) followed by inhibition of the protein calcineurin (CaN) by the binary CsA/Cyp complex and subsequent negative regulation of T-cell activation. In the present study we show a novel way to modify the CsA ring by selective N-hydroxyalkylation of the residues Val5 and d-Ala8. Moreover, the influence of these structural CsA modifications on the ability of the CsA analogs to bind Cyp, to inhibit CaN and to penetrate membranes of living cells was investigated. Our results show that the Val5 N-substitution significantly improved compound cell-permeability and markedly diminished CaN inhibition by the binary CsA analog/CypA complex but to a lesser extent Cyp inhibition. In contrast, the N-alkylation of d-Ala8 gave a product with significantly reduced affinity for Cyp but its immunosuppressive effects remained similar to CsA. Possible explanations of the observed experimental data are provided by computational studies.

Diagnostic and therapeutic single-operator cholangiopancreatoscopy with SpyGlassDS™: results of a multicenter retrospective cohort study.

BACKGROUND AND AIMS: The aim of the study was to evaluate the usefulness and diagnostic and therapeutic outcome of the single-operator cholangiopancreatoscopy (SOC) with SpyGlassDS™. METHODS: In a retrospective multicenter study between November 2015 and January 2017, SpyGlassDS™ procedures were analyzed in participating centers. Indications, accuracy of SOC-guided biopsies, management of large bile duct stones, and complications were analyzed. Follow-up was 4 months. RESULTS: Two hundred and six patients out of 250 examinations were evaluated. Indications were biliary stones (n = 132), bile duct stenosis (n = 93), stones and stenosis combined (n = 24), and bile duct leakage (n = 1). Of the 117 cases which were suspicious of malignancy, in 99 cases the lesion could be stratified into benign (n = 55) or malignant (n = 44) indicating a sensitivity of 95.5% and a specificity of 94.5% for the indication tumor. SOC-guided biopsies revealed a sensitivity of 57.7% with a specificity of 100%. In 107 examinations, biliary stones were visualized and could be completely removed in 91.1% with a need of three procedures (range 1-6) to achieve final stone clearance. In 75 cases, lithotripsy was performed and was successful in 71 cases (95%). Four out of 45 patients (8.9%) underwent cholecystectomy with surgical bile duct revision as a final therapy. Adverse Event (AE) occurred in 33/250 patients (13.2%) and Serious Adverse Event (SAE) occurred in 1/250 patients (0.4%). Cholangitis was 1% (n = 102) after peri-interventional administration of antibiotics and 12.8% (n = 148) without antibiotic prophylaxis (p < 0.001). CONCLUSIONS: SOC with SpyGlassDS™ became a new standard for the diagnosis of indefinite biliary lesions and therapy of large bile duct stones. The diagnostic yield of SOC-guided biopsies facilitated a definite diagnosis in most cases and should be improved by standardized biopsy protocols. SOC-guided interventions allowed removal of large biliary stones by SOC-guided lithotripsy. The complication rate of 13.2% can be considerably reduced by use of a single-shot antibiotic treatment.