In vivo targeting of intestinal and extraintestinal transglutaminase 2 by coeliac autoantibodies

Portal hypertension aggravates Helicobacter pylori induced liver injury in mice via activating pyroptosis pathway

In recent years, it has been discovered that the pathogenic effect of Helicobacter pylori (H. pylori) is not only limited to the gastroduodenal region, but also plays a certain role in the occurrence and development of liver diseases. The aim of this study is to ascertain the existence of Helicobacter pylori translocation, investigate whether it leads to liver injury and its potential mechanism and examine whether portal hypertension exacerbates liver damage caused by H. pylori translocation. Twenty four male SPF C57BL/6J mice were divided into four groups (6 in each group): (1) control group (Normal); (2) portal hypertension group (PHT); (3) H. pylori infected group (Hp); (4) H. pylori and Portal hypertension group (Hp and PHT). The histopathological changes of the liver and gastric tissues were measured by HE staining and immunohistochemistry (IHC); ALT, AST, IL-6 and INF-γ was measured by ELISA; Western blot detected the expression of pyroptotic proteins in the liver. The pro-inflammatory mediators and liver function indexes of mice in Hp group, Hp and PHT group were higher than those in the normal and PHT group. In addition, the liver inflammatory cell infiltration and ballooning of the two groups of mice were more severe than those in the normal group and PHT group, Hp and PHT group were more severe; Hp group, Hp and PHT group mice liver tissues activated the pyroptotic process through NLRP3 inflammasome, which eventually led to cell damage. Post mice infection by H. pylori, H. pylori will translocate to the liver, and induce liver injury by aggravating inflammation and promoting pyroptosis. Moreover, when portal hypertension occurs, it promotes the displacement of H. pylori, thereby aggravating liver injury.

Development of Cell-Assembled Human Endomysial-Type Biomatrix Substrate for the Detection of Celiac Disease Autoantibodies

The endomysial antibody (EMA) immunofluorescent test is a highly specific method to detect disease-specific autoantibodies in celiac disease (CD) by their binding to natural transglutaminase-2 autoantigen in tissue sections, and it is used as a compulsory confirmatory test in the non-invasive diagnosis of CD. The classical EMA substrates are the monkey esophagus and the human umbilical cord. It is increasingly difficult to use these tissues due to ethical concerns and animal welfare regulations. In this study, we developed, in cell culture, an endomysium-type extracellular biomatrix assembled by human umbilical cord vein-derived endothelial cells which binds CD antibodies in a similar pattern as monkey esophagus and has similar macromolecular composition. Evaluating retrospectively and prospectively tested patient cohorts, including 130 CD cases and 105 non-celiac controls, IgA-class celiac antibody detection on the biomatrix was equally specific (100%) as EMA testing on tissues, and had higher sensitivity (95.6% versus 91.2%). Both EMA tests were less sensitive, but more specific than transglutaminase-based ELISA measurements. The decellularization of the biomatrix improved sensitivity, enabled the detection of IgG-class celiac antibodies, and allowed for simple reading without previous training. This easily available cell-assembled biomatrix substrate may replace substrate tissues in diagnostic EMA testing in the future.

Causality between Celiac disease and kidney disease: A Mendelian Randomization Study

Celiac disease, characterized as an autoimmune disorder, possesses the capacity to affect multiple organs and systems. Earlier research has indicated an increased risk of kidney diseases associated with celiac disease. However, the potential causal relationship between genetic susceptibility to celiac disease and the risk of kidney diseases remains uncertain. We conducted Mendelian randomization analysis using nonoverlapping European population data, examining the link between celiac disease and 10 kidney traits in whole-genome association studies. We employed the inverse variance-weighted method to enhance statistical robustness, and results' reliability was reinforced through rigorous sensitivity analysis. Mendelian randomization analysis revealed a genetic susceptibility of celiac disease to an increased risk of immunoglobulin A nephropathy (OR = 1.44; 95% confidence interval [CI] = 1.17-1.78; P = 5.7 × 10-4), chronic glomerulonephritis (OR = 1.15; 95% CI = 1.08-1.22; P = 2.58 × 10-5), and a decline in estimated glomerular filtration rate (beta = -0.001; P = 2.99 × 10-4). Additionally, a potential positive trend in the causal relationship between celiac disease and membranous nephropathy (OR = 1.37; 95% CI = 1.08-1.74; P = 0.01) was observed. Sensitivity analysis indicated the absence of pleiotropy. This study contributes novel evidence establishing a causal link between celiac disease and kidney traits, indicating a potential association between celiac disease and an elevated risk of kidney diseases. The findings provide fresh perspectives for advancing mechanistic and clinical research into kidney diseases associated with celiac disease.

Severe Liver Damage in an Obese Patient: Onset of Celiac Disease or Overlap Syndrome?

Celiac disease (CeD) is an enteropathy caused by the complex interaction between genetic, environmental, and individual immunological factors. Besides the hallmark of intestinal mucosal damage, CeD is a systemic disorder extending beyond the gastrointestinal tract and impacting various other organs, causing extraintestinal and atypical symptoms. The association between CeD and liver damage has been classified into three main categories: mild and asymptomatic liver injury, autoimmune liver injury, and liver failure. We present a case of severe liver damage with cirrhotic evolution in an obese 12-year-old boy who had been admitted due to generalized jaundice and localized abdominal pain in the right hypochondrium. In the course of investigating the etiology of severe liver disease, toxic, infectious, metabolic, obstructive, and genetic causes were excluded. Despite the patient's obesity, a diagnosis of CeD was established, and in accordance with autoimmune hepatitis (AIH) criteria, the patient was diagnosed with autoantibody-negative AIH associated to CeD.

Prevalence of autoimmune, cholestatic and nonalcoholic fatty liver disease in celiac disease

BACKGROUND

While there is higher prevalence of autoimmune, cholestatic and fatty liver disease in celiac disease (CeD), most data is from small-scale studies. We evaluated the prevalence and risk factors of the same using large cohort data.

METHODS

A population-based cross-sectional study was conducted using Explorys, a multi-institutional database. Prevalence and risk factors of autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and nonalcoholic fatty liver disease (NAFLD) in CeD were assessed.

RESULTS

Out of 70 352 325 subjects, 136 735 had CeD (0.19%). The prevalence of AIH (0.32%), PBC (0.15%), PSC (0.004%) and NAFLD (0.7%) were high in CeD. After adjusting for age, gender, Caucasian race and anti-tissue transglutaminase antibody (anti-TTG), CeD subjects had higher odds of AIH [adjusted odds ratio (aOR) 7.06, 95% confidence interval (CI) 6.32-7.89] and PBC (aOR 4.16, 95% CI 3.46-5.0). Even after adjusting for CeD, anti-TTG positivity concurred with higher odds of AIH (aOR 4.79, 95% CI 3.88-5.92) and PBC (aOR 9.22, 95% CI 7.03-12.1). After adjusting for age, gender, Caucasian race, diabetes mellitus (DM), obesity, hypothyroidism and metabolic syndrome, there was higher prevalence of NAFLD in CeD, with the aOR in the presence of DM type 1 being 2.1 (95% CI 1.96-2.25), and in the presence of DM type 2 being 2.92 (95% CI 2.72-3.14).

CONCLUSION

Subjects with CeD are more likely to have AIH, PBC, PSC and NAFLD. AIH and PBC have higher odds in the presence of anti-TTG. The odds of NAFLD in CeD are high regardless of type of DM.

The Oral Transglutaminase 2 Inhibitor ZED1227 Accumulates in the Villous Enterocytes in Celiac Disease Patients during Gluten Challenge and Drug Treatment

The enzyme transglutaminase 2 (TG2) plays a key role in celiac disease (CeD) pathogenesis. Active TG2 is located mainly extracellularly in the lamina propria but also in the villous enterocytes of the duodenum. The TG2 inhibitor ZED1227 is a promising drug candidate for treating CeD and is designed to block the TG2-catalyzed deamidation and crosslinking of gliadin peptides. Our aim was to study the accumulation of ZED1227 after oral administration of the drug. We studied duodenal biopsies derived from a phase 2a clinical drug trial using an antibody that detects ZED1227 when bound to the catalytic center of TG2. Human epithelial organoids were studied in vitro for the effect of ZED1227 on the activity of TG2 using the 5-biotin-pentylamine assay. The ZED1227-TG2 complex was found mainly in the villous enterocytes in post-treatment biopsies. The signal of ZED1227-TG2 was strongest in the luminal epithelial brush border, while the intensity of the signal in the lamina propria was only ~20% of that in the villous enterocytes. No signal specific to ZED1227 could be detected in pretreatment biopsies or in biopsies from patients randomized to the placebo treatment arm. ZED1227-TG2 staining co-localized with total TG2 and native and deamidated gliadin peptides on the enterocyte luminal surface. Inhibition of TG2 activity by ZED1227 was demonstrated in epithelial organoids. Our findings suggest that active TG2 is present at the luminal side of the villous epithelium and that inhibition of TG2 activity by ZED1227 occurs already there before gliadin peptides enter the lamina propria.

Bi-directional Relationship Between Celiac Disease and Liver Chemistries: A Systematic Review and Meta-Analysis

AIMS

Previous studies have reported conflicting results regarding prevalence of elevated LC (2-70%) in celiac disease (CD). This systematic review and meta-analysis assessed the prevalence of elevated LC at time of CD diagnosis and associated response to GFD. We also report the prevalence of CD in patients with unexplained elevation of LC.

METHODS

Studies assessing LC (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) in CD patients were eligible. Studies with < 50 cases or in pediatric populations were excluded.

RESULTS

In total, 20 studies assessing prevalence of elevated LC in 4,265 participants with newly diagnosed CD (mean age = 35.6 ± 6.5 years, 69.8% female) were included. Pooled prevalence of elevated LC was 18.7% (95% CI 13.8-24.8; I2 = 95%). Normalization of elevated LC was seen in 83.1% (95% CI 73.4-89.7; I2 = 79%, 11 studies) of patients after GFD. On meta-regression, age at CD diagnosis, gender, and Marsh grading were not associated with elevated LC. Among 979 participants (7 studies) with unexplained elevation of LC, pooled seroprevalence and biopsy-proven CD was 6.4% (95% CI 2.9-10.3, I2 = 71%) and 4.5% (95% CI 2.6-7.7, I2 = 67%), respectively.

CONCLUSION

Elevated LC are seen in approximately one-fifth of patients at CD diagnosis with majority normalizing after GFD. Age, gender, and degree of intestinal damage are not predictive of elevated LC. In the appropriate clinical scenario, liver tests should be serially monitored in CD reserving workup for additional causes after a trial of GFD. Patients with unexplained elevation of liver tests should be screened for celiac disease.

Identification of celiac disease associated IgA nephropathy by IgA anti-tissue transglutaminase2 antibody deposits in archived formalin-fixed tissues

BACKGROUND

The causal association between IgA nephropathy (IgAN) and celiac disease (CeD) is based on their clinical coexistence. In this prospective study, we screened patients with IgAN for CeD and explored the utility of analysis of IgA anti-TG2 antibody deposits, for establishing a causal association.

METHODS

Biopsy-proven patients of IgAN were screened for serum IgA anti-tissue transglutaminase antibody (IgA anti-tTG Ab) titer and thereafter were invited to undergo endoscopic duodenal biopsy. Corresponding duodenal and kidney biopsies were subjected to IgA anti-TG2 antibody colocalization study using dual-color immunohistochemistry and immunofluorescence techniques. Additionally, kidney biopsies from 105 patients with IgAN who did not give consent for serology analysis, 30 non-IgA nephropathies, and 10 normal controls were also included. Dual-color-stained slides were interpreted based on stain distribution and intensity scores, and Pearson's index >0.3-1 on confocal imaging was considered significant.

RESULTS

Of a cohort of 151 patients with IgAN, 32 consented to undergo sero-screening and 5 of them had high serum anti-tTG Ab titer. Two out of the latter consented to endoscopic duodenal biopsies, in whom modified Marsh grade 3b changes were identified. Strong IgA anti-TG2 antibody deposits were noted in the kidney and duodenal biopsies of these patients. One patient out of non-consenting 105 patients with IgAN and 3 out of 30 patients with other non-IgA nephropathies also showed IgA anti-TG2 deposits. None of the healthy kidney tissues showed IgA anti-TG2 Ab deposits.

CONCLUSIONS

Co-localized IgA anti-TG2 deposits in the kidney biopsies in patients with IgAN help to establish a pathogenic link with CeD. A small proportion of patients with IgAN have associated CeD.

Usefulness of a double immunofluorescence technique for detection of intestinal tTG-IgA deposits in diabetic and non-diabetic children with celiac disease

BACKGROUND

Celiac disease (CD) is frequently associated with type I diabetes mellitus (T1D), where its diagnosis may be a challenging task. This study aims to test the usefulness of the double staining immunofluorescence (dsIF) technique for the detection of intestinal anti-tissue transglutaminase specific IgA antibody (tTG-IgA) deposits in CD and T1D children with coexisting CD.

METHODS

A total of 46 patients (30 cases of CD and 16 cases of T1D with CD) and 16 non-diabetic, non-celiac children were recruited. Endoscopic biopsies were taken and analyzed by light microscopy, quantitative histology (QH), and a dsIF technique.

RESULTS

Histologically, villous atrophy was most severe in CD, followed by T1D with CD, while all control biopsies except 1 were normal. QH showed a statistically significant difference in villous height (Vh), crypt depth (CrD), and Vh:CrD ratio between diabetic and non-diabetic patients with CD. dsIF technique could detect tTG-IgA deposits in 85.7% of cases of CD alone and 93.8% of biopsies from diabetic children. Surprisingly, deposits were more extensive in biopsies with minimal villous shortening. Also, all 5 biopsies from T1D patients with normal histology were dsIF positive.

CONCLUSION

In-situ analysis of tTG-IgA immune deposits facilitates the detection of positive serology early-onset CD. Quantitative analysis may be used as an ancillary tool to increase the reliability of histological findings in these patients.

Rapid immunochromatography on fresh intestinal biopsy is highly accurate in detecting intestinal anti-transglutaminase antibodies

OBJECTIVE

Intestinal anti-transglutaminase antibodies (I-Anti-TG2) are a specific marker of Celiac Disease (CeD). The aim of this study was to evaluate the diagnostic accuracy of a novel application of an immunochromatographic assay referred as Rapid_AntiTG2 to detect I-Anti-TG2 on intestinal biopsy lysate.

DESIGN

Consecutive pediatric patients referred to a single center for elective upper endoscopy were enrolled. Biopsies were taken from duodenal bulb and distal duodenum. For each sampling site 2 biopsies was analyzed for standard histology, 1 biopsy was cultured to perform the reference standard assay for I-Anti-TG2 detection (EMA-biopsy) and 1 biopsy was mechanically lysed to perform Rapid_AntiTG2. The primary outcome was the diagnostic accuracy of Rapid_AntiTG2 on biopsy lysate compared to the gold standard (serology + histopathology) for CeD diagnosis. The secondary outcome was the agreement of Rapid_AntiTG2 with EMA-biopsy.

RESULTS

148 patients were included. Of these 79 were CeD (64 Classical CeD, 2 Seronegative CeD and 13 Potential CeD) and 69 were controls. Rapid_AntiTG2 on biopsy lysate had a very high diagnostic accuracy (sensitivity 100%, specificity 97%, LR+34.1, LR- 0.01) in separating patients with CeD from controls. Diagnostic accuracy was unchanged in patients with potential and seronegative CeD. Rapid_AntiTG2 on biopsy lysate had almost perfect agreement with the EMA-biopsy reference test (99% agreement, Cohen's K .97).

CONCLUSION

I-Anti-TG2 can be detected with an immunochromatographic assay after simple mechanical lysis of fresh intestinal biopsy with very high diagnostic accuracy. The test is quick and easy to perform and can be widely available in any endoscopy unit. Its implementation would allow a better understanding of the prognostic value of I-Anti-TG2 and help clinicians in cases of suspected CeD that are difficult to classify.

Celiac Disease and Neurological Manifestations: From Gluten to Neuroinflammation

Celiac disease (CD) is a complex multi-organ disease with a high prevalence of extra-intestinal involvement, including neurological and psychiatric manifestations, such as cerebellar ataxia, peripheral neuropathy, epilepsy, headache, cognitive impairment, and depression. However, the mechanisms behind the neurological involvement in CD remain controversial. Recent evidence shows these can be related to gluten-mediated pathogenesis, including antibody cross-reaction, deposition of immune-complex, direct neurotoxicity, and in severe cases, vitamins or nutrients deficiency. Here, we have summarized new evidence related to gut microbiota and the so-called "gut-liver-brain axis" involved in CD-related neurological manifestations. Additionally, there has yet to be an agreement on whether serological or neurophysiological findings can effectively early diagnose and properly monitor CD-associated neurological involvement; notably, most of them can revert to normal with a rigorous gluten-free diet. Moving from a molecular level to a symptom-based approach, clinical, serological, and neurophysiology data might help to disentangle the many-faceted interactions between the gut and brain in CD. Eventually, the identification of multimodal biomarkers might help diagnose, monitor, and improve the quality of life of patients with "neuroCD".

Novel association of gluten sensitivity with immune-mediated neuromuscular syndrome in a dog

Gluten-related disorders in humans comprise different entities, including coeliac disease. Patients typically have measurable titers of anti-gliadin IgG or IgA (AGAs) and anti-transglutaminase-2 IgA (TG2). In addition to intestinal symptoms, human patients often show various neurological complications. In dogs, the neurological manifestation is rarely reported. Here we describe the muscle and nerve biopsies of an 11-year-old, male Border Terrier presenting with lower motor neuron signs submitted for histological examination. Examination of the biopsies showed an oligofocal lymphohistiocytic and plasmocytic myositis and a diffuse neuropathy of mixed nodo-paranodal and demyelinating type. Suspecting a neuromuscular form of breed-related gluten hypersensitivity, measurements of AGAs and TG2 antibodies were performed. Both titers ranged above control values. Hence, a gluten-related neuromyopathy was diagnosed. A gluten-free diet was prescribed and a complete disappearance of clinical signs was observed. Gluten-related disorders should be considered as a differential diagnosis in dogs with intestinal and neuromuscular signs.

"Long-term follow-up and prognosis of celiac hepatitis"

INTRODUCTION

Celiac disease has been associated with abnormal liver function tests at diagnosis that usually resolve with a gluten-free diet (GFD). The aim of this study was to assess the evolution of liver involvement and possible long-term complications in patients on a GFD.

METHODS

Retrospective and single-center study, which included all individuals with Celiac disease followed in specialized consultation in a tertiary referral hospital.

RESULTS

A total of 162 patients were included, most of them female (77.8%) with a median age of 24 years (IQR, 7-39). Seventy-four (45.7%) patients had abnormal liver function tests at diagnosis. These individuals had higher anti-tissue transglutaminase IgA (tTG-IgA) antibody titers (126 vs. 29 IU/L; P  = 0.003). There were no significant differences in the Marsh classification ( P  = 0.599). During follow-up, most celiac hepatitis patients had normalization of liver function tests and tTG-IgA antibodies. At the last follow-up, all the patients had fibrosis-4 index <2.4 and an aspartate aminotransferase-to-platelet ratio index score <0.6. Vibration-controlled transient elastography showed values <6.4 kPa in all cases. On the other hand, it was found that 42.9% of the individuals had a controlled attenuation parameter >206.5 db/m.

CONCLUSIONS

In our cohort, liver function tests normalized in the vast majority of celiac hepatitis patients on a GFD, with no progression to chronic liver disease. It should be noted the high number of individuals who present hepatic steatosis during follow-up, which may be related to a diet that tends to be hyperlipidemic and hypercaloric.

Type 2 Transglutaminase in Coeliac Disease: A Key Player in Pathogenesis, Diagnosis and Therapy

Type 2 transglutaminase (TG2) is the main autoantigen in coeliac disease (CD), a widespread inflammatory enteropathy caused by the ingestion of gluten-containing cereals in genetically predisposed individuals. As a consequence, serum antibodies to TG2 represent a very useful marker in CD diagnosis. However, TG2 is also an important player in CD pathogenesis, for its ability to deamidate some Gln residues of gluten peptides, which become more immunogenic in CD intestinal mucosa. Given the importance of TG2 enzymatic activities in CD, several studies have sought to discover specific and potent inhibitors that could be employed in new therapeutical approaches for CD, as alternatives to a lifelong gluten-free diet. In this review, we summarise all the aspects regarding TG2 involvement in CD, including its enzymatic reactions in pathogenesis, the role of anti-TG2 antibodies in disease management, and the exploration of recent strategies to reduce deamidation or to use transamidation to detoxify gluten.

Recognizing the Emergent and Submerged Iceberg of the Celiac Disease: ITAMA Project-Global Strategy Protocol

Coeliac disease (CD) is frequently underdiagnosed with a consequent heavy burden in terms of morbidity and health care costs. Diagnosis of CD is based on the evaluation of symptoms and anti-transglutaminase antibodies IgA (TGA-IgA) levels, with values above a tenfold increase being the basis of the biopsy-free diagnostic approach suggested by present guidelines. This study showcased the largest screening project for CD carried out to date in school children (n=20,000) aimed at assessing the diagnostic accuracy of minimally invasive finger prick point-of-care tests (POCT) which, combined with conventional celiac serology and the aid of an artificial intelligence-based system, may eliminate the need for intestinal biopsy. Moreover, this study delves deeper into the "coeliac iceberg" in an attempt to identify people with disorders who may benefit from a gluten-free diet, even in the absence of gastrointestinal symptoms, abnormal serology and histology. This was achieved by looking for TGA-IgA mucosal deposits in duodenal biopsy. This large European multidisciplinary health project paves the way to an improved quality of life for patients by reducing the costs for diagnosis due to delayed findings of CD and to offer business opportunities in terms of diagnostic tools and support.

Emerging Biomarkers for Screening and Management of Celiac Disease

Celiac disease (CeD) is a chronic, immune-mediated enteropathy that is precipitated by dietary gluten in genetically predisposed individuals expressing HLA-DQ2 and/or HLA-DQ8. In the current clinical practice, there are many serologic studies to aid in the diagnosis of CeD which include autoantibodies like IgA antitissue transglutaminase, antiendomysium, and antideamidated forms of gliadin peptide antibodies. Small intestinal biopsy has long been considered an essential step for the diagnosis of CeD. However, in the recent era, researchers have explored the possibility of CeD screening and diagnosis without endoscopy or biopsy. The newer emerging biomarkers of CeD appear promising in diagnostic evaluation and subsequent monitoring of disease. In this review of literature, we have explored the emerging biomarker-based diagnostic evaluation and monitoring of CeD.

Injection of prototypic celiac anti-transglutaminase 2 antibodies in mice does not cause enteropathy

Background

Celiac disease is an autoimmune enteropathy driven by dietary intake of gluten proteins. Typical histopathologic features are villous flattening, crypt hyperplasia and infiltration of inflammatory cells in the intestinal epithelium and lamina propria. The disease is hallmarked by the gluten-dependent production of autoantibodies targeting the enzyme transglutaminase 2 (TG2). While these antibodies are specific and sensitive diagnostic markers of the disease, a role in the development of the enteropathy has never been established.

Methods

We addressed this question by injecting murine antibodies harboring the variable domains of a prototypic celiac anti-TG2 immunoglobulin into TG2-sufficient and TG2-deficient mice evaluating for celiac enteropathy.

Results

We found no histopathologic abnormalities nor clinical signs of disease related to the injection of anti-TG2 IgG or IgA.

Conclusions

Our findings do not support a direct role for secreted anti-TG2 antibodies in the development of the celiac enteropathy.

THE RELATIONSHIP BETWEEN GLUTEN ENTEROPATHY AND NAIL CAPILEROSCOPY FINDINGS AND DISEASE ACTIVATION

Objective: Nailfold Videocapilloroscopy (NVC) is an examination method that is used as an aid in the diagnosis, follow-up, and treatment strategy of rheumatic diseases such as systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, and gives an idea about microcirculation by examining the vascular bed. It is a cheap, easily applicable, and quickly accessible method. Because of these features, we aimed to use the NVC method in patients with Gluten Enteropathy (GE) to determine whether this method will be a helpful technique in the diagnosis, activation decision, remission follow-up, and treatment strategy in patients with GE. Methods: In this study, 67 patients diagnosed with GE (n=35 disease-active group (AGE), n=32 disease-related remission group (RGE), and control group (CG)-27 healthy people whose diagnosis of GE was ruled out were included in this study. Group and CG were divided into ten parameters in capillary pathologies (capillary density loss, dilated capillary, giant capillary, microhemorrhage, avascular area, tortuosity, branched capillary, disorganization, extravasation, angiogenesis). They were divided into two groups as RGE and compared with the results obtained from NVC measurements Results: When patients diagnosed with GE and CG were evaluated in terms of capillary disorder with NVC, While all of the patients with capillary disorders were in the GE group, no capillary disorders were found in the control group (p

Changes in Non-Deamidated versus Deamidated Epitope Targeting and Disease Prediction during the Antibody Response to Gliadin and Transglutaminase of Infants at Risk for Celiac Disease

Celiac disease (CeD) is a conditional autoimmune disorder with T cell-mediated immune response to gluten coupled with antibody production to gliadin and the self-protein tissue transglutaminase (TG2). TG2 contributes to the CeD pathomechanism by deamidating gliadin, thereby generating more immunogenic peptides. Anti-gliadin antibodies may appear before the autoantibody production. The scope of this study was to dissect these early antibody responses by investigating serum samples collected during the PreventCD prospective double-blind study, where infants with high CeD risk were randomized to 200 mg daily gluten intake or placebo from 4 to 6 months of age, followed by frequent blood testing on regular gluten consumption in both groups. After primary gluten intake, children with or without later CeD produced IgA and IgG antibodies which preferentially recognized non-deamidated gliadin peptides. At CeD development with anti-TG2 seroconversion, there was a significant increase in the antibody reaction toward deamidated gliadin peptides (DGP), with maturation in the binding strength for the PEQPFP gamma-gliadin core peptide. The earliest produced autoantibodies targeted TG2’s celiac epitope 2. Our results reveal a qualitative change in the gliadin-directed humoral immune response at the time when anti-TG2 antibodies appear, but anti-DGP antibodies in the absence of anti-TG2 antibodies are not disease-predictive.

Liver involvement in patients with coeliac disease: proof of causality using IgA/anti-TG2 colocalisation techniques

AIMS

Despite clinical evidence of liver involvement in patients with coeliac disease (CeD), there is a lack of a method to prove this association.

METHODS

Of 146 treatment-naive patients with CeD, 26 had liver dysfunction. Liver biopsies and corresponding small intestinal biopsies were obtained from these 26 patients. Multicolour immunohistochemical and immunofluorescence confocal microscopic studies were performed on paraffin-embedded tissue to detect the IgA/anti-TG2 deposits. Follow-up liver biopsies were taken after a gluten-free diet.

RESULTS

Twenty-six out of the 146 patients (17.8%) with suspected coeliac-associated liver disease on histological examination revealed irregular sinusoidal dilatation in 15 (57.6%), steatohepatitis in 4 (15.3%), non-specific chronic hepatitis in 3 (11.5%), autoimmune hepatitis in 2 (7.6%) biopsies, including cirrhosis in one of them, irregular perisinusoidal fibrosis and changes of non-cirrhotic portal fibrosis in one biopsy each (3.8%). IgA/anti-tTG deposits were observed in 22 (84.6%) liver biopsies by dual immunohistochemistry technique, and in 24 (92.3%) by confocal immunofluorescence technique and in all corresponding duodenal biopsies (100%). Overall, IgA/anti-tTG deposits showed 100% sensitivity, 77% specificity and 85% positive predictive value for establishing an association of extraintestinal pathology and CeD using archived tissues. Follow-up liver biopsies could be obtained in five patients; four of them showed not only resolution of the histological lesions but disappearance of IgA/anti-tTG co-localisation.

CONCLUSIONS

Data of the present study adds to the body of evidence that liver lesions in patients with CeD are disease related and may have been caused by a similar pathogenic mechanism that causes intestinal changes.

Screening-detected positive serology for celiac disease: a real clinical challenge

According to European Society for Paediatric Gastroenterology, Hepatology, and Nutrition 2020 criteria for celiac disease diagnosis, the small bowel biopsy (SBB) can be omitted in selected circumstances, even in asymptomatic patients. Hence, we have conducted a retrospective study to identify the histological findings of the asymptomatic patients with antitransglutaminase IgA antibodies 10 times above the upper limit of normal and positive antiendomisium antibodies; 5/24 patients fulfilling these criteria had, however, a nonconclusive SBB and were diagnosed with potential celiac disease. The nonbiopsy approach in these cases needs to be carefully evaluated and the risk of overdiagnosis pondered as the management and evolution of potential celiac disease cases is still a matter of study.

Intestinal anti-tissue transglutaminase IgA deposits as a complementary method for the diagnostic evaluation of celiac disease in patients with low-grade histological lesions

Evaluating the usefulness of intestinal anti-transglutaminase IgA (anti-TG2 IgA) deposits detection as a complementary or decision-supporting tool in the diagnosis of celiac disease (CD) in patients with low degree of enteropathy. Small intestinal biopsies (SIB) were performed from 2008 to 2017 in patients on suspicion of CD (positive CD serology and/or symptoms) referred to our Pediatric Gastroenterology Unit. We determined anti-TG2 IgA deposits by using double immunofluorescence in all the patients in whom Marsh 0 or Marsh1 was detected in the conventional histological study and in a random selection of patients with clearly positive serology and histological Marsh 2-3 lesion. 75 pediatric patients were split into 3 groups according to the final diagnosis: 1) 13 children with a Marsh 0 or 1, negative CD serology and final non-CD diagnosis;none presented intestinal anti-TG2 IgA deposits; 2) 15 potential CD cases (Marsh 0 or 1 and CD-associated antibodies), detecting anti-TG2 IgA deposits in 12; on follow-up, another biopsy performed in 11/15 showed villi atrophy in 7 and a Marsh 2 lesion in two of them, patients being finally diagnosed as CD cases; and 3) 47 children with Marsh 2-3 histological lesion and final CD diagnosis; all of them had intestinal anti-TG2 IgA deposits. Anti-TG2 deposits are a useful complementary tool for CD diagnosis in pediatric population with digestive pathologies suggestive of CD. It is especially helpful in those with low grade lesion, in which anti-TG2 deposits are predictive of the development of more severe lesions on follow-up.

S2k guidelines (consensus statement) for diagnosis and therapy of dermatitis herpetiformis initiated by the European Academy of Dermatology and Venereology (EADV)

INTRODUCTION

Dermatitis herpetiformis (DH) is a chronic, pruritic, gluten-induced skin disorder characterized by subepidermal granular IgA deposition and a variable degree of enteropathy identical to that seen in coeliac disease. So far, there has been no European consensus about the management of DH.

METHODS

The guidelines were created by small subgroups of a guideline committee consisting of 26 specialists from various medical fields and one patients' representative. The members of the committee then discussed the guidelines and voted for the final version at two consensus meetings. The guidelines were developed under the support of the European Academy of Dermatology and Venereology (EADV) and in collaboration with the European Dermatology Forum (EDF).

RESULTS

The guidelines summarize evidence-based and expert-based recommendations (S2 level) for the management of DH (see Appendix).

CONCLUSION

These guidelines will improve the quality of management of DH and support dermatologists in their diagnostic and therapeutic decisions.

Celiac Disease-Type Tissue Transglutaminase Autoantibody Deposits in Kidney Biopsies of Patients with IgA Nephropathy

An association between celiac disease and IgA nephropathy (IgAN) has been suggested. In celiac disease, in addition to circulating in serum, IgA-class tissue transglutaminase (tTG) autoantibodies are deposited in the small bowel mucosa and extraintestinal organs. In this case series of IgAN patients with or without celiac disease, we studied whether celiac disease-type IgA-tTG deposits occur in kidney biopsies. The study included nine IgAN patients, four of them with celiac disease. At the time of the diagnostic kidney biopsy serum tTG autoantibodies were measured and colocalization of IgA and tTG was investigated in the frozen kidney biopsies. Three IgAN patients with celiac disease had IgA-tTG deposits in the kidney even though in two of these the celiac disease diagnosis had been set years later. These deposits were not found in a patient with already diagnosed celiac disease following a gluten-free diet. Of the five non-celiac IgAN patients, three had IgA-tTG deposits in the kidney. We conclude that tTG-targeted IgA deposits can be found in the kidney biopsies of gluten-consuming IgAN patients but their specificity to celiac disease seems limited.

Celiac disease in pediatric patients according to HLA genetic risk classes: a retrospective observational study

BACKGROUND

Celiac disease (CD) is an autoimmune enteropathy in which HLA-DQ haplotypes define susceptibility. Our aim was to evaluate if belonging to a certain HLA-DQ class risk could be associated to the clinical, serological and histological presentation of CD.

METHODS

We performed a retrospective observational monocentric study including all 300 patients diagnosed with CD, who underwent HLA typing. Clinical, serological and histological data was collected from clinical records and their association with HLA-DQ class risk was verified through statistical tests.

RESULTS

In our sample mean age at onset was 6.7 ± 4.2 years, with a prevalence of females (n = 183; 61%), typical symptoms (n = 242; 80.6%) and anti-tTG IgA ≥ 100 U/mL (n = 194; 64.7%). Family history was present only in 19% (n = 57) of patients, and it was not significantly associated with any of the clinical and demographical data analyzed or the belonging to a certain HLA-DQ class risk. We found in the male population more frequently a coexistence of CD and atopic syndrome (males: n = 47; 40.2%; females: n = 50; 27.3%; p = 0.020). Early age of onset, instead, was associated with typical symptoms (m = 6.4 ± 4; p = 0.045) and elevated liver enzymes (m = 5 ± 3.8; p < 0.001), while later age of onset was associated with presence of other autoimmune diseases (m = 8.2 ± 4; p = 0.01). We observed statistically significant influences of HLA class risk on antibodies and liver enzymes levels: G1, G4 and G2 classes showed more frequently anti-tTG IgA ≥ 100 U/mL (n = 44; 80%, n = 16; 69.6%, n = 48; 67.6% respectively; p-value = 0.037), and in patients from G2 class we found enhanced liver enzymes (n = 28; 39.4%; p-value = 0.005). HLA class risk was still significantly associated with anti-tTG ≥ 100 (p = 0.044) and with hypertransaminasemia (p = 0.010) after a multiple logistic regression adjusted for the effect of gender, age at onset and family history.

CONCLUSIONS

We failed to prove an association between HLA-DQ genotypes and the clinical features in our CD pediatric patients. Although, our results suggest an effect of the DQB1-02 allele not only on the level of antibodies to tTG, but possibly also on liver involvement.

Nonbiopsy Approach for Celiac Disease Is Accurate When Using Exact Duodenal Histomorphometry: Prospective Study in 2 Countries

GOALS

To test the accuracy of serology-based criteria for diagnosing celiac disease utilizing quantitative histomorphometry.

BACKGROUND

The revised European pediatric guidelines allow noninvasive celiac disease diagnosis for a subgroup of children. However, in some of the studies on this issue, the positive predictive value (PPV) of serology has remained suboptimal, possibly because of challenges of histopathology as the reference standard.

STUDY

Prospectively enrolled children with transglutaminase 2 antibodies (TGA) above the upper limit of normal (ULN) underwent blood sampling and duodenal biopsy in Finland and Romania. Those with TGA ≥10× ULN, positive endomysium antibodies (EmA), and disease-associated genetics were considered to fulfill triple criteria for celiac disease. Initial histopathologic analysis was conducted using grouped classification, whereupon centralized morphometry was performed.

RESULTS

Altogether 88 (54%) children were triple positive. In local evaluation, 99% of triple-positive children and 73% of children with TGA <10× ULN had celiac disease. These figures increased to 100% and 85% after more precise morphometric analysis. Triple-positive children had more anemia and higher median EmA and liver enzyme values than those with TGA<10× ULN; the groups were comparable in other clinical features and laboratory parameters.

CONCLUSIONS

When applied as recommended, the nonbiopsy strategy had already yielded excellent PPV regardless of the site of diagnosis or clinical presentation in the local analysis. PPV further increased to 100% with standardized duodenal morphometry.

Celiac Disease and Elevated Liver Enzymes: A Review

Aminotransferases are commonly found to be elevated in patients with celiac disease in association with two different types of liver dysfunction: cryptogenic liver disorders and autoimmune disorders. The purpose of this review is to discuss the mechanisms by which aminotransferases become elevated in celiac disease, clinical manifestations, and response to gluten-free diet. Many studies have shown that celiac patients with cryptogenic liver disease have normalization in aminotransferases, intestinal histologic improvement and serologic resolution after 6-12 months of strict gluten-free diet. In patients with an underlying autoimmune liver disease, simultaneous treatment for both conditions resulted in normalized elevated aminotransferases. The literature suggests that intestinal permeability may be at least one of the mechanisms by which liver damage occurs. Patients with celiac disease should have liver enzymes routinely checked and treated with a strict gluten-free diet if found to be abnormal. Lack of improvement in patients who have strictly adhered to gluten-free diet should prompt further workup for other causes of liver disease.

Seronegative Celiac Disease; Frequently Encountered Yet Undiagnosed Clinical Entity

BACKGROUND There are limited studies on the seronegative celiac disease from the Indian subcontinent. The aim of this study was to assess the prevalence, pathological, genetic, and clinical profile of patients with seronegative celiac disease. METHODS This prospective observational study was conducted in the Department of Gastroenterology, SMS Hospital, Jaipur, between October 2017 to March 2019. Consecutive patients with seronegative celiac disease with age ≥ 3 years were enrolled for the assessment of demography, clinical features, histological findings, celiac serology, genetic analysis, and response to gluten-free diet. RESULTS Out of total of 312 patients with celiac disease, 13 (4.16 %) patients (median age 25 years [range 5-46 years], 10 female) were diagnosed as having seronegative celiac disease. Presenting symptoms were chronic diarrhea in nine (69.23%), abdominal pain in six (46.15%), weight loss in five (38.46%), and short stature in two (15.38 %) patients. On histological analysis, Marsh stage 2 was seen in five (38.46%), Marsh 3c in two (15.38%), Marsh 3a in three (23.07%), and Marsh 3b in three (23.07%) patients. On HLA analysis, HLA-DQ2.5 was seen in six (46.15%) patients, HLA-DQ2.2 in five (38.46%), and HLA-DQ8 in two (15.38%) patients. CONCLUSION The prevalence of seronegative celiac disease in our study was 4.16%. The most common symptoms were chronic diarrhea and abdominal pain, and the histological grade was Marsh stage 2.

Circulating PV-1 as a marker of celiac disease-associated liver injury

Aim: To investigate the role of endothelial PV-1 in patients with untreated celiac disease (CD)-associated liver injury. Materials & methods: PV-1 and PV-1 mRNA were measured in intestinal biopsies from untreated CD patients with elevated or normal alanine transaminase levels, controls, patients with inflammatory bowel disease and patients with toxic liver injury. Circulating PV-1 levels were also evaluated. Results: Circulating PV-1 levels were significantly increased in the serum of patients with CD-associated liver injury and reverted to normal following a gluten-free diet. Mucosal PV-1 and PV-1 mRNA were no different in patients with CD-associated liver injury. Conclusion: Serum but not mucosal PV-1 represents a marker of gluten-dependent liver injury and response to a gluten-free diet in patients with untreated CD.

Human intestinal dendritic cell and macrophage subsets in coeliac disease

Dendritic cells (DC) and macrophages (Mϕ) constitute the most abundant antigen presenting cells in the human intestinal mucosa. In resting conditions, they are essential to maintain the mechanisms of immune tolerance toward food antigens and commensals, at the time that they keep the capacity to initiate and maintain antigen-specific pro-inflammatory immune responses toward invading pathogens. Nevertheless, this delicate equilibrium between immunity and tolerance is not perfect, like in coeliac disease (CD), where DC and Mϕ drive the development of antigen-specific immune responses toward dietary gluten peptides. In this review, we provide therefore a comprehensive discussion about CD pathogenesis, the human intestinal immune system and the biology of intestinal DC and Mϕ both in resting conditions and in CD. Last, but not least, we discuss about all the remaining issues pending to be studied regarding DC and Mϕ contribution toward CD pathogenesis. This may allow the identification of unique and specific factors which may be useful in the clinical practice, as well as identify new therapeutic targets in order to reestablish the loss intestinal homeostasis in CD.

B cell tolerance and antibody production to the celiac disease autoantigen transglutaminase 2

Autoantibodies to transglutaminase 2 (TG2) are hallmarks of celiac disease. To address B cell tolerance and autoantibody formation to TG2, we generated immunoglobulin knock-in (Ig KI) mice that express a prototypical celiac patient-derived anti-TG2 B cell receptor equally reactive to human and mouse TG2. We studied B cell development in the presence/absence of autoantigen by crossing the Ig KI mice to Tgm2-/- mice. Autoreactive B cells in Tgm2+/+ mice were indistinguishable from their naive counterparts in Tgm2-/- mice with no signs of clonal deletion, receptor editing, or B cell anergy. The autoreactive B cells appeared ignorant to their antigen, and they produced autoantibodies when provided T cell help. The findings lend credence to a model of celiac disease where gluten-reactive T cells provide help to autoreactive TG2-specific B cells by involvement of gluten-TG2 complexes, and they outline a general mechanism of autoimmunity with autoantibodies being produced by ignorant B cells on provision of T cell help.

Helicobacter pylori infection: Beyond gastric manifestations

Helicobacter pylori (H. pylori) is a bacterium that infects more than a half of world's population. Although it is mainly related to the development of gastroduodenal diseases, several studies have shown that such infection may also influence the development and severity of various extragastric diseases. According to the current evidence, whereas this bacterium is a risk factor for some of these manifestations, it might play a protective role in other pathological conditions. In that context, when considered the gastrointestinal tract, H. pylori positivity have been related to Inflammatory Bowel Disease, Gastroesophageal Reflux Disease, Non-Alcoholic Fatty Liver Disease, Hepatic Carcinoma, Cholelithiasis, and Cholecystitis. Moreover, lower serum levels of iron and vitamin B12 have been found in patients with H. pylori infection, leading to the emergence of anemias in a portion of them. With regards to neurological manifestations, a growing number of studies have associated that bacterium with multiple sclerosis, Alzheimer's disease, Parkinson's disease, and Guillain-Barré syndrome. Interestingly, the risk of developing cardiovascular disorders, such as atherosclerosis, is also influenced by the infection. Besides that, the H. pylori-associated inflammation may also lead to increased insulin resistance, leading to a higher risk of diabetes mellitus among infected individuals. Finally, the occurrence of dermatological and ophthalmic disorders have also been related to that microorganism. In this sense, this minireview aims to gather the main studies associating H. pylori infection with extragastric conditions, and also to explore the main mechanisms that may explain the role of H. pylori in those diseases.

Celiac Disease and Portal Hypertension: A Causal Association or Just a Coincidence?

INTRODUCTION

Celiac disease (CD) has been linked to portal hypertension (PHT) of varied etiology, but the causality association has never been proved. We aim to study the prevalence of CD in patients of PHT of different etiology.

METHODS

A prospective observational study was conducted from June 2017 to December 2018 involving all the cases of PHT of varied etiology. Consecutive patients of PHT with chronic liver disease (CLD) of defined etiology like ethanol, viral hepatitis (B or C), Budd-Chiari syndrome (BCS), autoimmune-related cirrhosis, and cryptogenic CLD (cCLD) (group A) and those with noncirrhotic PHT (NCPHT), which included noncirrhotic portal fibrosis (NCPF) and extrahepatic portal vein obstruction (EHPVO) (group B), were screened for CD by IgA anti-tTG antibody followed by duodenal biopsy in serology-positive patients.

RESULTS

Out of a total of 464 patients, group A constituted 382 patients, CLD related to ethanol (155), cCLD (147), hepatitis B (42), hepatitis C (21), autoimmune (10), and BCS (7), whereas 82 patients were in group B with NCPF (64) and EHPVO (18). Total 29 patients were diagnosed with CD in both groups, 17 in group A (4.5%) and 12 in group B (14.6%). In group A, 13 patients with cCLD, two with HBV-related CLD, one with BCS, and one with autoimmune-related CLD were concomitantly diagnosed as CD. In group B, CD was diagnosed in 12 patients of NCPF (11) and EHPVO (1). Liver histology showed chronic hepatitis in two patients and was normal in three patients.

CONCLUSION

CD is common in PHT of different etiology, especially in cCLD, NCPH and autoimmune hepatitis; however, the etiological basis for this association is still to be defined. The likelihood of CD is higher in liver disease than the general population, and these patients should be screened for CD.

Intestinal Anti-tissue Transglutaminase2 Autoantibodies: Pathogenic and Clinical Implications for Celiac Disease

Celiac disease (CD) is a systemic disease that primarily affects the small intestine. The presence of anti-tissue transglutaminase 2 (anti-TG2) antibodies in the serum, as well as the presence of autoimmune phenomena, account for the inclusion of CD among autoimmune diseases. Anti-TG2 autoantibodies are produced at intestinal level, where they are deposited even before they appear in circulation. The pathogenic events that lead to their production are still not completely defined, but a central role seems to be played by gliadin-specific T cells. Interestingly, limited somatic mutations have been observed in VH and VL genes in TG2-specific plasma cells, another important aspect being the biased use of a heavy chain encoded by the VH5 gene. Conflicting data have been produced over the years on the effect of anti-TG2 antibodies on TG2 function. Although the presence of anti-TG2 antibodies in serum is considered a hallmark of CD and relevant from a clinical viewpoint, the role of these autoantibodies in the development of the celiac lesion remains to be defined. In the years, different technical approaches have been implemented to detect and measure intestinal CD-associated autoantibody production. Two aspects can make intestinal anti-TG2 antibodies relevant: from a clinical viewpoint: the first is their proposed ability in potential coeliac patients to predict the development of a full-blown enteropathy; the second is their possible role in revealing a condition of reactivity to gluten in patients with no circulating CD-associated autoantibodies. In fact, the detection of CD-specific autoantibodies production in the intestine, in the absence of serum positivity for the same antibodies, could be suggestive of a very early condition of gluten reactivity; alternatively, it could be not specific for CD and merely attributable to intestinal inflammation. In conclusion, the role of mucosal anti-TG2 antibodies in pathogenesis of CD is unknown. Their presence, the modalities of their production, their gluten dependence render them a unique model to study autoimmunity.

Interplay between Type 2 Transglutaminase (TG2), Gliadin Peptide 31-43 and Anti-TG2 Antibodies in Celiac Disease

Celiac disease (CD) is a common intestinal inflammatory disease involving both a genetic background and environmental triggers. The ingestion of gluten, a proteic component of several cereals, represents the main hexogen factor implied in CD onset that involves concomitant innate and adaptive immune responses to gluten. Immunogenicity of some gluten sequences are strongly enhanced as the consequence of the deamidation of specific glutamine residues by type 2 transglutaminase (TG2), a ubiquitous enzyme whose expression is up-regulated in the intestine of CD patients. A short gluten sequence resistant to intestinal proteases, the α-gliadin peptide 31-43, seems to modulate TG2 function in the gut; on the other hand, the enzyme can affect the biological activity of this peptide. In addition, an intense auto-immune response towards TG2 is a hallmark of CD. Auto-antibodies exert a range of biological effects on several cells, effects that in part overlap with those induced by peptide 31-43. In this review, we delineate a scenario in which TG2, anti-TG2 antibodies and peptide 31-43 closely relate to each other, thus synergistically participating in CD starting and progression.

The Long-Term Safety and Quality of Life Effects of Oats in Dermatitis Herpetiformis

The treatment of choice for dermatitis herpetiformis (DH), a cutaneous manifestation of coeliac disease, is a life-long gluten-free diet (GFD). In a GFD, wheat, rye and barley should be strictly avoided, but the role of oats is more controversial. This study aimed to investigate the safety and long-term quality of life and health effects of oat consumption in 312 long-term treated DH patients. Baseline data were gathered from patient records and follow-up data from questionnaires or interviews, and validated questionnaires were used to assess quality of life. We found that altogether 256 patients (82%) were consuming oats as part of their GFD at the follow-up. Long-term follow-up data showed that there were no differences in the presence of long-term illnesses, coeliac disease complications or the usage of medication between those consuming and not consuming oats. However, oat consumers had a better quality of life and reported ongoing gastrointestinal symptoms less frequently (4% vs 19%, p = 0.004) at the follow-up than those not consuming oats. The study established that oats are safe for DH patients and in the long-term seem to improve the quality of life of DH patients.

Progress in the serology-based diagnosis and management of adult celiac disease

Introduction: This article provides a comprehensive overview of the development and application of serological tests used routinely in clinical practice for the diagnosis and management of adult celiac disease.Areas covered: We summarize existing scientific literature related to anti-endomyseal, anti-tissue transglutaminase, and anti-deamidated gliadin peptide antibodies and detail the current and potential future applications of these tests in celiac disease.Expert commentary: Current serological tests in celiac disease have some of the best performance characteristics among disease-specific tests. However, in adult celiac disease, current diagnostic algorithms still rely on duodenal biopsies to confirm the diagnosis. A 'biopsy avoidance strategy' has been implemented in pediatric celiac disease. Future high-quality studies will help inform on whether this approach can be implemented into adult gastroenterology services. It is envisaged that the next 5 years will see an increasing reliance on serology in the diagnosis of adult celiac disease.

Intestinal TG3- and TG2-Specific Plasma Cell Responses in Dermatitis Herpetiformis Patients Undergoing a Gluten Challenge

Dermatitis herpetiformis (DH), a cutaneous manifestation of coeliac disease, is characterized by transglutaminase (TG) 3-targeted dermal immunoglobulin A (IgA) deposits. The treatment for DH is the same as for coeliac disease, namely a life-long gluten-free diet. DH patients typically have gluten-dependent circulating autoantibodies targeting TG3 and TG2, and plasma cells secreting such autoantibodies have been detected in the small intestinal mucosa. This study investigates the gluten-responsiveness of intestinal TG3 and TG2 antibody-secreting plasma cells in 16 treated DH patients undergoing a gluten challenge. The frequency of both plasma cell populations increased significantly during the challenge, and their frequency correlated with the corresponding serum autoantibody levels at post-challenge. TG3-specific plasma cells were absent in all 18 untreated coeliac disease patients and seven non-coeliac control subjects on gluten-containing diets. These findings indicate that, in DH, both intestinal TG3- and TG2-antibody secreting plasma cells are gluten-dependent, and that TG3-antibody secreting plasma cells are DH-specific.

Current Concepts of Dermatitis Herpetiformis

Dermatitis herpetiformis (DH) is an autoimmune skin disease that causes itchy, blistering rash, typically on the elbows, knees and buttocks. DH and coeliac disease share the same genetic background, gluten-dependent enteropathy and antibody response against tissue transglutaminase. DH is currently considered a cutaneous manifestation of coeliac disease, and the prevailing hypothesis is that DH develops as a late manifestation of subclinical coeliac disease. The incidence of DH is decreasing contemporarily with the increasing incidence of coeliac disease. The IgA immune response in DH skin is directed against epidermal transglutaminase, while the autoantigen in the gut is tissue transglutaminase. Granular IgA deposition in the papillary dermis is pathognomonic for DH, and is a finding used to confirm the diagnosis. The treatment of choice for DH is a life-long gluten-free diet, which resolves the rash and enteropathy, increases quality of life, and offers a good long-term prognosis.

Diagnostic accuracy and applicability of intestinal auto-antibodies in the wide clinical spectrum of coeliac disease

BACKGROUND

Intestinal coeliac auto-antibodies are the marker of coeliac disease (CD). Since the determination of these antibodies is still not widely available, we used immunoassays to identify the most suitable technology for revealing intestinal auto-antibodies in the wide clinical spectrum of CD.

METHODS

Intestinal auto-antibodies have been prospectively investigated in CD suspected children using two immunoassays: intestinal-deposits of IgA anti-tissue transglutaminase antibodies (anti-tTG) and biopsy-culture IgA anti-endomysium (AEA). Intestinal IgM antibodies have been determined in IgA-deficient subjects.

FINDINGS

Two-hundred and twenty-one suspected CD patients were enrolled. Intestinal antibodies were tested positive for both assays in classical CD patients (n = 178) with villous atrophy and positive serum-CD antibodies, potential CD patients (n = 16) with normal intestinal mucosa and positive serum-CD antibodies, and pre-potential CD patients (n = 14) with normal intestinal mucosa and negative serum-CD antibodies. In 13/221 with normal intestinal mucosa, negative CD-serum antibodies and negative intestinal antibodies CD has been excluded. All classical, 14/16 potential and 11/14 pre-potential CD patients on gluten-free diet (GFD) improved their symptoms. In 9/11 pre-potential patients intestinal antibodies disappeared on GFD. Both assays were negative in 69/71 control subjects. The two assays showed high diagnostic sensitivity (100%) and specificity (99%).

INTERPRETATION

Intestinal CD-antibodies make prompt diagnosis in the wide clinical spectrum of CD reducing the delay in diagnosis and treatment, especially in pre-potential CD patients. The easy handling biopsy culture assay is an effective diagnostic tool which should be carried out by any gastroenterology unit to recognize all CD clinical manifestations.

FUNDING

Interreg Central-Europe, IRCCS "Burlo Garofolo".

Histological, immunohistochemical and mRNA gene expression responses in coeliac disease patients challenged with gluten using PAXgene fixed paraffin-embedded duodenal biopsies

Background

There is an unmet need for novel treatments, such as drugs or vaccines, adjunctive to or replacing a burdensome life-long gluten-free diet for coeliac disease. The gold standard for successful treatment is a healed small intestinal mucosa, and therefore, the outcome measures in proof-of-concept studies should be based on evaluation of small intestine biopsies. We here evaluated morphometric, immunohistochemical and messenger RNA (mRNA) expression changes in coeliac disease patients challenged with gluten using PAXgene fixed paraffin-embedded biopsies.

Methods

Fifteen coeliac disease patients were challenged with 4 g of gluten per day for 10 weeks and 24 non-coeliac patients served as disease controls. A wide array of histological and immunohistochemical staining and mRNA-based gene expression tests (RT-qPCR and RNAseq) were carried out.

Results

Digital quantitative villous height: crypt depth ratio (VH: CrD) measurements revealed significant duodenal mucosal deterioration in all coeliac disease patients on gluten challenge. In contrast, the Marsh-Oberhuber class worsened in only 80% of coeliac patients. Measuring the intraepithelial CD3⁺ T-lymphocyte and lamina propria CD138⁺ plasma cell densities simultaneously proved to be a meaningful new measure of inflammation. Stainings for γδ T cells and IgA deposits, where previously frozen samples have been needed, were successful in PAXgene fixed paraffin-embedded samples. Messenger RNA extraction from the same paraffin-embedded biopsy block was successful and allowed large-scale qRT-PCR and RNAseq analyses for gene expression. Molecular morphometry, using the mRNA expression ratio of villous epithelium-specific gene APOA4 to crypt proliferation gene Ki67, showed a similar significant distinction between paired baseline and post-gluten challenge biopsies as quantitative histomorphometry.

Conclusion

Rigorous digitally measured histologic and molecular markers suitable for gluten challenge studies can be obtained from a single paraffin-embedded biopsy specimen. Molecular morphometry seems to be a promising new tool that can be used in situations where assessing duodenal mucosal health is of paramount importance. In addition, the diagnostically valuable IgA deposits were now stained in paraffin-embedded specimens making them more accessible in routine clinics.

Association between Helicobacter pylori infection and nonalcoholic fatty liver: A meta-analysis

BACKGROUND

Opinion regarding whether Helicobacter pylori infection can promote the occurrence and development of nonalcoholic fatty liver (NAFLD) is divided. Therefore, we aimed to assess the exact relationship between H pylori infection and NAFLD by integrating all available data.

METHODS

The articles about H pylori infection and NAFLD were collected by searching the databases of PubMed, Embase, Web of Science, Scopus, China National Knowledge Infrastructure, and WanFang. The random-effects model was used for data analysis, followed by subgroup analysis and meta-regression to explore sources of heterogeneity.

RESULTS

Twenty-one articles were included in the study. Pooled analysis showed that H pylori infection indeed promoted NAFLD. Subgroup analysis and regression analysis showed that case-control ratio may be one of the sources of heterogeneity.

CONCLUSIONS

H pylori infection is indeed one of the factors that promotes the progression of NAFLD for the Asian population. This provides new approaches for clinical prevention and treatment for NAFLD.

The Challenge of Treatment in Potential Celiac Disease

Potential celiac disease (PCD) is defined by the presence of positive serum antibodies, HLA-DQ2/DQ8 haplotypes, and a normal small intestinal mucosa (Marsh grade 0-1). This condition occurs in one-fifth of celiac disease (CD) patients and usually represents a clinical challenge. We reviewed genetic, histologic, and clinical features of this specific condition by performing a systematic search on MEDLINE, Embase, and Scholar database. Accordingly, we identified different genetic features in patients with PCD compared to the classical forms. Frequently, signs of inflammation (deposits of immunoglobulin A (IgA) and/or increased number of intraepithelial lymphocytes) can be clearly identify in the mucosa of PCD patients after an accurate histological assessment. Finally, the main challenge is represented by the treatment: the gluten-free diet should be considered only in the presence of gluten-dependent symptoms in both children and adults. What is known: (i) potential celiac disease (PCD) occurs in one-fifth of all celiac diseases (CD), and (ii) despite the absence of classical lesions, clear signs of inflammation are often detectable. What is new: (i) patients with PCD show different genetic features, and (ii) the presence of gluten-dependent symptoms is the main determinant to initiate the gluten-free diet, after a complete diagnostic work-up.

Diagnosing Celiac Disease: Towards Wide-Scale Screening and Serology-Based Criteria?

Celiac disease is one of the most common food-related chronic disorders in children. Unfortunately, this multifaceted disease is challenging to recognize and remains markedly underdiagnosed. Screening of either known at-risk groups or even the whole population could increase the suboptimal diagnostic yield substantially. Many recent guidelines recommend screening of at least selected risk groups, but more wide-scale screening remains controversial. The increasing prevalence of celiac disease and the development of autoantibody assays have also led to a gradual shift in the diagnostics towards less invasive serology-based criteria in a subgroup of symptomatic children. The main open questions concern whether these criteria are applicable to all countries and clinical settings, as well as to adult patients. On the other hand, widening screening and the mistaken practice of initiating a gluten-free diet before the appropriate exclusion of celiac disease increase the number of borderline seropositive cases, which may also challenge the classical histopathological diagnostics. Sophisticated diagnostic methods and a deeper understanding of the natural history of early developing celiac disease may prove useful in these circumstances.