Inflammatory bowel disease and celiac disease: Overlaps and differences

Prevalence and clinical characteristics of children with coexisting coeliac disease and inflammatory bowel disease

OBJECTIVE

Growing evidence suggests that coeliac disease (CeD) is more common in patients with inflammatory bowel disease (IBD) but diagnostic confusion remains due to overlapping histological and clinical features. Few studies have investigated this relationship in children. We aimed to assess the prevalence of CeD in our paediatric IBD cohort and define the characteristics of IBD when CeD coexists.

METHODS

We conducted a retrospective study of all patients <18 years old diagnosed with IBD in Southampton Children's Hospital between January 2019 and December 2023. Patients were identified using our IBD database, and data were collected on diagnosis, endoscopy, histopathology, serology, IBD treatment and surgery using electronic patient records.

RESULTS

18 of the 479 children with IBD were also diagnosed with CeD (3.75%). 14 underwent duodenal biopsy on gluten, with 13 fulfilling Marsh classification 2-3. Eight children had Crohn's disease, five had ulcerative colitis and five had IBD-unclassified. 16 out of 18 demonstrated colonic disease; 11 out of 18 had pancolitis. There was no significant difference in the rate of biological therapy use between the IBD-CeD and non-coeliac groups (50% vs 68%). No patients with IBD-CeD underwent IBD surgery.

CONCLUSIONS

1 in 25 children with IBD had coexisting CeD. Pancolitis was the most prominent IBD phenotype but a diagnosis of CeD was not associated with increased escalation to biological therapy, and no patients required surgery. These findings help to describe the paediatric IBD-coeliac phenotype and demonstrate the importance of considering IBD in children with refractory CeD and screening for CeD in children presenting with IBD.

The CXCR3/PLC/IP3-IP3R axis is responsible for the ignition of UPR in intestinal epithelial cells exposed to gliadin peptide, during the onset of celiac disease

BACKGROUND

Coeliac disease is an autoimmune disease that is primarily associated with chronic inflammation of the gut, but can also affect organs outside the gut, from the liver to the skin and CNS. The disease is triggered in predisposed individuals by a peptide mixture (PT) derived from the digestion of gliadin, a component of wheat, which is ingested with food. Although the induction of endoplasmic reticulum stress in intestinal epithelial cells (IECs) upon exposure to PT is known, the underlying molecular mechanisms remain unclear. Identifying the key players in this signaling pathway could therefore help to develop a new effective therapeutic strategy for the treatment of CD patients.

METHODS

Two CD models were used to identify the molecular mechanism linking extracellular PT and endoplasmic reticulum (ER) stress in the IECs of predisposed individuals exposed to gliadin. These models were an in vitro model based on CaCo-2 cells and an ex vivo model based on our previously described gut ex vivo system (GEVS), both exposed to PT.

RESULTS

Our results clearly show that the interaction of gliadin peptides with the transmembrane CXCR3 receptor on IECs leads to a rapid induction of PLC activity that generates IP3 molecules. This second messenger binds to the IP3R located in ER membranes, resulting in calcium efflux from the organelle.

CONCLUSION

The PT-dependent ER stress observed in the IECs of CD patients results from the excessive release of calcium from the ER. Importantly, inhibition of this signaling pathway abrogates ER stress, which in turn attenuates downstream signs of CD, such as TG2 expression and gut permeability dysregulation, as well as inhibits inflammation.

European Consensus on Malabsorption-UEG & SIGE, LGA, SPG, SRGH, CGS, ESPCG, EAGEN, ESPEN, and ESPGHAN: Part 2: Screening, Special Populations, Nutritional Goals, Supportive Care, Primary Care Perspective

Malabsorption is a complex and multifaceted condition characterised by the defective passage of nutrients into the blood and lymphatic streams. Several congenital or acquired disorders may cause either selective or global malabsorption in both children and adults, such as cystic fibrosis, exocrine pancreatic insufficiency (EPI), coeliac disease (CD) and other enteropathies, lactase deficiency, small intestinal bacterial overgrowth (SIBO), autoimmune atrophic gastritis, Crohn's disease, and gastric or small bowel resections. Early recognition of malabsorption is key for tailoring a proper diagnostic work-up for identifying the cause of malabsorption. Patient's medical and pharmacological history are essential for identifying risk factors. Several examinations like endoscopy with small intestinal biopsies, non-invasive functional tests, and radiologic imaging are useful in diagnosing malabsorption. Due to its high prevalence, CD should always be looked for in case of malabsorption with no other obvious explanations and in high-risk individuals. Nutritional support is key in management of patients with malabsorption; different options are available, including oral supplements, enteral or parenteral nutrition. In patients with short bowel syndrome, teduglutide proved effective in reducing the need for parenteral nutrition, thus improving the quality of life of these patients. Primary care physicians have a central role in early detection of malabsorption and should be involved into multidisciplinary teams for improving the overall management of these patients. In this European consensus, involving 10 scientific societies and several experts, we have dissected all the issues around malabsorption, including the definitions and diagnostic testing (Part 1), high-risk categories and special populations, nutritional assessment and management, and primary care perspective (Part 2).

Roles of prostaglandins in immunosuppression

Prostaglandins (PGs) play a crucial and multifaceted role in various physiological processes such as intercellular signaling, inflammation regulation, neurotransmission, vasodilation, vasoconstriction, and reproductive functions. The diversity and biological significance of these effects are contingent upon the specific types or subtypes of PGs, with each PG playing a crucial role in distinct physiological and pathological processes. Particularly within the immune system, PGs are essential in modulating the function of immune cells and the magnitude and orientation of immune responses. Hence, a comprehensive comprehension of the functions PG signaling pathways in immunosuppressive regulation holds substantial clinical relevance for disease prevention and treatment strategies. The manuscript provides a review of recent developments in PG signaling in immunosuppressive regulation. Furthermore, the potential clinical applications of PGs in immunosuppression are also discussed. While research into the immunosuppressive effects of PGs required further exploration, targeted therapies against their immunosuppressive pathways might open new avenues for disease prevention and treatment.

Review article: A practical approach to persistent gastrointestinal symptoms in inflammatory bowel disease in remission

BACKGROUND

Persistent gastrointestinal symptoms are prevalent in adult patients with inflammatory bowel disease (IBD), even when endoscopic remission is reached. These symptoms can have profound negative effects on the quality of life of affected patients and can be difficult to treat. They may be caused by IBD-related complications or comorbid disorders, but they can also be explained by irritable bowel syndrome (IBS)-like symptoms.

AIMS

To provide a practical step-by-step guide to diagnose and treat persistent gastrointestinal symptoms in patients with IBD in remission via a personalised approach.

METHODS

We scrutinised relevant literature on causes, diagnostics and treatment of persistent gastrointestinal symptoms (abdominal pain or discomfort, bloating, abdominal distension, diarrhoea, constipation and faecal incontinence) in patients with IBD in remission.

RESULTS

A graphical practical guide for several steps in diagnosing, identifying potential triggers and adequate treatment of persistent gastrointestinal symptoms in IBD in remission is provided based on supporting literature. The first part of this review focuses on the diagnostic and treatment approaches for potential IBD-related complications and comorbidities. The second part describes the approach to IBS-like symptoms in IBD in remission.

CONCLUSIONS

Persistent gastrointestinal symptoms in IBD in remission can be traced back to potential pathophysiological mechanisms in individual patients and can be treated adequately. For both IBD-related complications and comorbidities and IBS-like symptoms in IBD in remission, pharmacological, dietary, lifestyle or psychological treatments can be effective. A systematic and personalised approach is required to reduce the burden for patients, healthcare systems, and society.

The immunological understanding on germinal center B cells in psoriasis

The development of psoriasis is mainly driven by the dysregulation of T cells within the skin, marking a primary involvement of these cells in the pathogenesis. Although B cells are integral components of the immune system, their role in the initiation and progression of psoriasis is not as pivotal as that of T cells. The paradox of B cell suggests that, while it is crucial for adaptive immunity, B cells may contribute to the exacerbation of psoriasis. Numerous ideas proposed that there are potential relationships between psoriasis and B cells especially within germinal centers (GCs). Recent research projected that B cells might be triggered by autoantigens which then induced molecular mimicry to alter B cells activity within GC and generate autoantibodies and pro-inflammatory cytokines, form ectopic GC, and dysregulate the proliferation of keratinocytes. Hence, in this review, we gathered potential evidence indicating the participation of B cells in psoriasis within the context of GC, aiming to enhance our comprehension and advance treatment strategies for psoriasis thus inviting many new researchers to investigate this issue.

Exploring the molecular mechanisms and shared gene signatures between celiac disease and ulcerative colitis based on bulk RNA and single-cell sequencing: Experimental verification

Many immune-mediated diseases have the common genetic basis, as an autoimmune disorder, celiac disease (CeD) primarily affects the small intestine, and is caused by the ingestion of gluten in genetically susceptible individuals. As for ulcerative colitis (UC), which most likely involves a complex interplay between some components of the commensal microbiota and other environmental factors in its origin. These two autoimmune diseases share a specific target organ, the bowel. The etiology and immunopathogenesis of both conditions characterized by chronic intestinal inflammation, ulcerative colitis and celiac disease, are not completely understood. Both are complex diseases with genetics and the environmental factors contributing to dysregulation of innate and adaptive immune responses, leading to chronic inflammation and disease. This study is designed to further clarify the relationship between UC and CeD. The GEO database was used to download gene expression profiles for CeD (GSE112102) and UC (GSE75214). The GSEA KEGG pathway analysis revealed that immune-related pathways were significantly associated with both diseases. Further, we screened 187 shared differentially expressed genes (DEGs) of the two diseases. Gene Ontology (GO) and WikiPathways were carried out to perform the biological process and pathway enrichment analysis. Subsequently, based on the DEGs, the least absolute shrinkage and selection operator (LASSO) analysis was performed to screen for the diagnostic biomarkers of the diseases. Moreover, single-cell RNA-sequencing (RNA-seq) data from five colonic propria with UC showed that REG4 expression was present in Goblet cell, Enteroendocrine cell, and Epithelial. Finally, our work identified REG4 is the shared gene of UC and CeD via external data validation, cellular experiments, and immunohistochemistry. In conclusion, our study elucidated that abnormal immune response could be the common pathogenesis of UC and CeD, and REG4 might be a key potential biomarker and therapeutic target for the comorbidity of these two diseases.

m6A Methylated Long Noncoding RNA LOC339803 Regulates Intestinal Inflammatory Response

Cytokine mediated sustained inflammation increases the risk to develop different complex chronic inflammatory diseases, but the implicated mechanisms remain unclear. Increasing evidence shows that long noncoding RNAs (lncRNAs) play key roles in the pathogenesis of inflammatory disorders, while inflammation associated variants are described to affect their function or essential RNA modifications as N6-methyladenosine (m6A) methylation, increasing predisposition to inflammatory diseases. Here, the functional implication of the intestinal inflammation associated lncRNA LOC339803 in the production of cytokines by intestinal epithelial cells is described. Allele-specific m6A methylation is found to affect YTHDC1 mediated protein binding affinity. LOC339803-YTHDC1 interaction dictates chromatin localization of LOC339803 ultimately inducing the expression of NFκB mediated proinflammatory cytokines and contributing to the development of intestinal inflammation. These findings are confirmed using human intestinal biopsy samples from different intestinal inflammatory conditions and controls. Additionally, it is demonstrated that LOC339803 targeting can be a useful strategy for the amelioration of intestinal inflammation in vitro and ex vivo. Overall, the results support the importance of the methylated LOC339803 lncRNA as a mediator of intestinal inflammation, explaining genetic susceptibility and presenting this lncRNA as a potential novel therapeutic target for the treatment of inflammatory intestinal disorders.

Helminth Lessons in Inflammatory Bowel Diseases (IBD)

Helminths are multicellular invertebrates that colonize the gut of many vertebrate animals including humans. This colonization can result in pathology, which requires treatment. It can also lead to a commensal and possibly even a symbiotic relationship where the helminth and the host benefit from each other's presence. Epidemiological data have linked helminth exposure to protection from immune disorders that include a wide range of diseases, such as allergies, autoimmune illnesses, and idiopathic inflammatory disorders of the gut, which are grouped as inflammatory bowel diseases (IBD). Treatment of moderate to severe IBD involves the use of immune modulators and biologics, which can cause life-threatening complications. In this setting, their safety profile makes helminths or helminth products attractive as novel therapeutic approaches to treat IBD or other immune disorders. Helminths stimulate T helper-2 (Th2) and immune regulatory pathways, which are targeted in IBD treatment. Epidemiological explorations, basic science studies, and clinical research on helminths can lead to the development of safe, potent, and novel therapeutic approaches to prevent or treat IBD in addition to other immune disorders.

Rectal prolapse as a manifestation of inflammatory bowel disease with celiac disease in a 2-year-old male: a rare case report

The co-occurrence of inflammatory bowel disease (IBD) and celiac disease (CeD) is uncommon. The typical sign of this co-occurrence is malabsorption which leads to anemia, diarrhea, and malnutrition. In rare cases, recurrent rectal prolapse may also occur.

Case presentation

A 2-year-old Syrian male baby presented with failure to thrive and chronic diarrhea for 18 months, along with recurrent rectal prolapse for the last 6 months. Biopsies taken confirmed a diagnosis of stage 3b celiac disease according to the Marsh classification. Furthermore, biopsies taken confirmed a diagnosis of IBD. Then, a high-fiber diet to manage IBD and celiac diet were both needed simultaneously, with signs of rectal prolapse, diarrhea, and bloating, occurring when either or both diets were stopped.

Clinical discussion

The diagnosis was initially explained by the malnutrition and anemia. Even after the gluten-free diet, the patient showed no improvement in diarrhea and developed inferior gastrointestinal bleeding suggested anal fissure, infectious colitis, polyps, IBD, or solitary rectal ulcer syndrome. The relationship between celiac disease and IBD, in children, is still unclear. Current studies suggest that such co-occurrence is associated with higher risks of developing other autoimmune-related disorders, growth and puberty delay, and comorbidities.

Conclusions

In the cases of pediatric co-occurrence of IBD and celiac disease, a conservative therapy consisting of two-fold diets for the two diseases should be tried first. If this step succeeds in controlling the clinical picture, it removes the necessity of introducing immunological pharmacologic treatments that may induce unfavorable side effects in a child.

Human glycoprotein-2 expressed in Brunner glands - A putative autoimmune target and link between Crohn's and coeliac disease

Glycoprotein 2 (GP2) is an autoantigen in Crohn's (CD) and coeliac disease (CeD). We assessed GP2-isoform (GP2_1-4)-expression in intestinal biopsies of paediatric patients with CD, CeD, ulcerative colitis (UC), and healthy children (HC). Transcription of GP2_1-4 was elevated in proximal small intestine in CeD and CD patients (only GP2_2/4) compared to jejunum (CeD/CD) and large bowel (CD). CeD patients demonstrated higher duodenal GP2_2/4-mRNA levels compared to HC/UC patients whereas CD patients showed higher GP2₄-mRNA levels compared to UC patients. Duodenal synthesis of only small GP2 isoforms (GP2_3/4) was demonstrated in epithelial cells in patients/HC and in Brunner glands (also large isoforms) with a more frequent apical location in CD/CeD patients. All four GP2 isoforms interacted with gliadin and phosphopeptidomannan. Gliadin digestion improved binding to GP2 isoforms. GP2_1-4 binding to CeD/CD-related antigens, elevated duodenal GP2_1-4-mRNA transcription, and GP2-protein secretion in Brunner glands of CeD/CD patients suggest an autoimmune CeD/CD link.

The Role of CD1 Gene Polymorphism in the Genetic Susceptibility to Spondyloarthropathies in the Moroccan Population and the Possible Cross-Link with Celiac Disease

Spondyloarthropathies (SpA) are a group of chronic inflammatory disorders usually affecting the axial spine and asymmetrical peripheral joints. Strong evidence links genetic and environmental factors to SpA pathogenesis. The HLA-B27 is the most important genetic factor associated with SpA. Nevertheless, the involvement of other HLA and non-HLA loci has been also reported. Some patients with SpA may also manifest features of celiac disease (CeD), thus suggesting a genetic overlap across these autoimmune diseases. Recently, CD1 glycoproteins, a class of molecules able to bind and present non peptidic antigens to T cells, aroused interest for their contribution to the pathogenesis of CeD. Therefore, to evaluate whether functional polymorphisms of CD1A and E genes also influence susceptibility to SpA, we analyzed 86 patients from Morocco affected by SpA and 51 healthy controls, using direct sequencing analysis. An increase of CD1E*01/01 homozygous genotype (p = 0.046) was found in SpA, compared with controls. CD1E*01/01 genotype was associated particularly to patients with sacroiliac joints/spine/peripheral joints pain (p = 0.0068), while a decrease of CD1E*01/02 genotype was evidenced compared to controls (p = 0.0065). Results from haplotypes analysis demonstrated that CD1A*02-E*02 decreased the risk of SpA, while CD1A*02-E*01 increased risk to develop disease. Our data indicate a relationship between CD1 genes and susceptibility to SpA in the Moroccan population and suggest the existence of shared genetic risk loci across SpA and CeD that might be useful to explain common pathogenetic features and define novel therapeutic strategies.

Causal association between celiac disease and inflammatory bowel disease: A two-sample bidirectional Mendelian randomization study

Background

An epidemiological link between celiac disease (CeD) and inflammatory bowel disease (IBD) has been well established recently. In this study, Mendelian randomization (MR) analysis was performed employing pooled data of publicly available genome-wide association studies (GWAS) to determine the causal relationship between CeD and IBD, encompassing ulcerative colitis (UC) and Crohn's disease (CD).

Methods

Dataset of CeD was acquired from GWAS for 12,041 cases and 12,228 controls. A GWAS of more than 86,000 patients and controls was used to identify genetic variations underlying IBD. MR analyses were performed with an inverse-variance-weighted approach, an MR-Egger regression, a weighted-mode approach, a weighted-median method, and sensitivity analyses of MR pleiotropy residual sum and outlie (MR-PRESSO).

Results

MR demonstrated that genetic predisposition to CeD was linked to a augmented risk of IBD (OR: 1.1408; 95% CI: 1.0614-1.2261; P = 0.0003). In the analysis of the two IBD subtypes, genetic predisposition to CeD was also linked to increased risks of UC (OR: 1.1646; 95% CI: 1.0614-1.2779; P = 0.0012) and CD (OR: 1.1865; 95% CI: 1.0948-1.2859; P = 3.07E-05). Reverse MR analysis results revealed that genetic susceptibility to IBD and CD was correlated with an augmented risk of CeD. However, there was no genetic correlation between UC and CeD. All of the above results were validated with other GWAS databases.

Conclusion

There is a bidirectional causal relationship of CeD with IBD and CD. However, UC only augments the risk of developing CeD.

Assessment of diagnostic value of HLA-DQ2/DQ8 typing and anti-tissue transglutaminase antibodies as an alternative to duodenal biopsy in pediatric celiac disease

Introduction/Objective. The objective of the paper is to assess the applicability of serum anti-tissue transglutaminase (tTG) antibodies IgA and IgG concentration and HLA-DQ2/DQ8 typing as a non-invasive alternative to duodenal biopsy in diagnosing celiac disease (CD) in pediatric population. Methods. A prospective cohort study included a total of 179 pediatric patients aged 1?18 years. Determination of tTG IgA and tTG IgG antibodies and human leukocyte antigen (HLA) DQ2/DQ8 typing was performed for all patients. Histology of duodenal biopsies was interpreted by the modified Marsh scoring system. Results. The diagnosis of CD was confirmed in 101 (56%) patients of the studied population. In cases of CD, HLA-DQ2/DQ8 was positive in 100 patients (99%). The tTG IgA antibodies in concentration higher than 100 U/ml were detected in 77 (76.2%) of the CD patients and in significantly smaller number for tTG IgG [29 (28.7%)] (p < 0.001). Statistically highly significant association of duodenal lesions Marsh grade 3 with concentration of tTG IgA 10-fold higher than the upper level of normal (ULN) was established (p < 0.001) Conclusion. Concentration of tTG IgA 10-fold higher than ULN is significantly positively correlated with Marsh grade 3 histopathology findings. Specific antibodies determination in combination with HLA-DQ2/ DQ8 typing proves to be sufficient for a diagnosis of CD, supporting the fact that duodenal biopsy may be avoided in a significant majority of patients ? 75%.

Gluten Degradation by the Gut Microbiota of Ulcerative Colitis Patients

Several studies have reported improved disease symptomatology in ulcerative colitis (UC) patients consuming a gluten free diet. This observation coupled with diversity depletion in the gut microbiota of UC patients led us to hypothesize that UC-associated enteric microbes differentially metabolize dietary gluten to produce immunogenic products that promote inflammation. Gluten concentration in stool was determined using gluten-specific ELISA, and gluten intake was assessed by food frequency questionnaire (FFQ) in UC (n = 12) and healthy controls (HC; n = 13). Gluten-metabolizing bacteria were isolated on minimal media supplemented with 1% gluten from UC and HC and identified by 16S rRNA profiling. Cell-free culture media from gluten metabolizing gut bacterial isolates was assessed for immunogenicity in vitro using HT29 colonocytes. Compared to HC, UC patients did not consume gluten differently (Mann−Whitney; p > 0.10) and exhibited equivalent levels of gluten in their feces (Mann−Whitney; p = 0.163). The profile of gluten-degrading bacteria isolated from UC stool was distinct (Chi-square; p ≤ 0.0001). Compared with Enterococcus isolates, products of gluten degradation by Bacillus strains induced higher IL8 and lower occludin (Mann−Whitney; p = 0.002 and p = 0.059, respectively) gene expression in colonocytes irrespective of whether they originated from UC or healthy gut. Members of HC and UC microbiota exhibit gluten-degrading ability, metabolites of which influence genes involved in inflammation and barrier function in enteric colonocyte cultures. Preliminary findings of this study warrant further investigations into the mechanisms by which gut microbiota contribute to UC pathogenesis through gluten degradation.

Gut homeostasis at a glance

The intestine, a rapidly self-renewing organ, is part of the gastrointestinal system. Its major roles are to absorb food-derived nutrients and water, process waste and act as a barrier against potentially harmful substances. Here, we will give a brief overview of the primary functions of the intestine, its structure and the luminal gradients along its length. We will discuss the dynamics of the intestinal epithelium, its turnover, and the maintenance of homeostasis. Finally, we will focus on the characteristics and functions of intestinal mesenchymal and immune cells. In this Cell Science at a Glance article and the accompanying poster, we aim to present the most recent information about gut cell biology and physiology, providing a resource for further exploration.

Inflammatory bowel disease and celiac disease: A bidirectional Mendelian randomization study

Objective: Although previous epidemiological studies have reported substantial links between inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), and celiac disease (CeD), the causal relationship between the two remains unknown. The purpose of the current study was to evaluate the bidirectional causation between IBD and CeD using Mendelian randomization (MR).

Method: We obtained genome-wide association study (GWAS) summary data of IBD (CD and UC) and CeD of thoroughly European ancestry from the IEU GWAS database. We screened eligible instrumental variables (IVs) according to the three assumptions of MR. MR was performed using MR-Egger, weighted median (WM), and inverse variance weighted (IVW) methods. The MR-Egger intercept and MR-PRESSO method investigated the horizontal pleiotropy effect. A leave-one-out analysis was performed to prevent bias caused by a single SNP.

Results: The study assessed a bidirectional causal effect between CD and CeD; CD increased the risk of CeD (IVW odds ratio (OR) = 1.27, 95% confidence interval (CI) = 1.19–1.35, p = 3.75E-13) and vice-a-versa (IVW OR = 1.09, 95% CI = 1.05–1.13, p = 1.39E-05). Additionally, CeD was influenced by IBD (IVW OR = 1.24, 95% CI = 1.16–1.34, p = 9.42E-10) and UC (IVW OR = 0.90, 95% CI = 0.83–0.98, p = 0.017). However, we observed no evidence of a causal relationship between CeD and IBD (IVW OR = 1.00, 95% CI = 0.97–1.04, p = 0.900) or UC (IVW OR = 0.96, 95% CI = 0.92–1.02, p = 0.172).

Conclusion: The present study revealed that IBD and CeD have a bidirectional causal relationship. However, it is slightly different from the results of previous observational studies, recommending that future studies focus on the mechanisms of interaction between CD and CeD.

Intestinal fatty acid binding protein is a disease biomarker in paediatric coeliac disease and Crohn's disease

Background

There is a clinical need to develop biomarkers of small bowel damage in coeliac disease and Crohn’s disease. This study evaluated intestinal fatty acid binding protein (iFABP), a potential biomarker of small bowel damage, in children with coeliac disease and Crohn’s disease.

Methods

The concentration iFABP was measured in plasma and urine of children with ulcerative colitis, coeliac disease, and Crohn’s disease at diagnosis and from the latter two groups after treatment with gluten free diet (GFD) or exclusive enteral nutrition (EEN), respectively. Healthy children (Controls) were also recruited.

Results

138 children were recruited. Plasma but not urinary iFABP was higher in patients with newly diagnosed coeliac disease than Controls (median [Q1, Q3] coeliac disease: 2104 pg/mL 1493, 2457] vs Controls: 938 pg/mL [616, 1140], p = 0.001). Plasma or urinary iFABP did not differ between patients with coeliac on GFD and Controls. Baseline iFABP in plasma decreased by 6 months on GFD (6mo GFD: 1238 pg/mL [952, 1618], p = 0.045). By 12 months this effect was lost, at which point 25% of patients with coeliac disease had detectable gluten in faeces, whilst tissue transglutaminase IgA antibodies (TGA) continued to decrease. At diagnosis, patients with Crohn’s disease had higher plasma iFABP levels than Controls (EEN Start: 1339 pg/mL [895, 1969] vs Controls: 938 pg/mL [616, 1140], p = 0.008). iFABP did not differ according to Crohn’s disease phenotype. Induction treatment with EEN tended to decrease (p = 0.072) iFABP in plasma which was no longer different to Controls (EEN End: 1114 pg/mL [689, 1400] vs Controls: 938 pg/mL [616, 1140], p = 0.164). Plasma or urinary iFABP did not differ in patients with ulcerative colitis from Controls (plasma iFABP, ulcerative colitis: 1309 pg/mL [1005, 1458] vs Controls: 938 pg/mL [616, 1140], p = 0.301; urinary iFABP ulcerative colitis: 38 pg/mg [29, 81] vs Controls: 53 pg/mg [27, 109], p = 0.605).

Conclusions

Plasma, but not urinary iFABP is a candidate biomarker with better fidelity in monitoring compliance during GFD than TGA. The role of plasma iFABP in Crohn’s disease is promising but warrants further investigation.

Trial registration: Clinical Trials.gov, NCT02341248. Registered on 19/01/2015.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02334-6.

The Association of Inflammatory Gut Diseases with Neuroinflammatory and Auditory Disorders

Disorders such as inflammatory bowel disease (IBD) and celiac disease (CeD) result in intestinal hyperpermeability or 'leaky' gut. The increased permeability of the intestinal barrier allows microbial metabolites, toxins, and pathogens to infiltrate the bloodstream and extraintestinal tissues, causing systemic inflammation. Despite differences in aetiology and pathophysiology, IBD and CeD share several extraintestinal manifestations such as neuroinflammation, neurological and psychiatric manifestations, and sensorineural hearing loss (SNHL). This narrative review focuses on the association between intestinal hyperpermeability with the brain and inner ear diseases. We postulate that the microbial metabolites and pathogens released from the gut increase the permeability of natural barriers, such as the blood-brain barrier (BBB) and blood-labyrinth barrier (BLB). The barrier breakdown allows the spreading of inflammatory processes to the brain and inner ear, leading to disease.

Patients With Inflammatory Bowel Disease on Treatment Have Lower Rates of Celiac Disease

BACKGROUND

The association between celiac disease and inflammatory bowel disease (IBD) has been studied; however, the impact of IBD therapy on celiac disease is not known. Using a large database, we sought to describe the association of celiac disease and IBD and the impact of IBD treatment.

METHODS

We queried a large multicenter database (Explorys Inc.), an electronic health record data aggregate from 26 American health care systems. We identified a cohort of patients with celiac disease and IBD between 1999 and 2020 and conducted a statistical analysis using a multivariate model.

RESULTS

Of the 72,965,940 individuals in the database, 133,400 had celiac disease (0.18%), 191,570 (0.26%) had ulcerative colitis (UC), and 230,670 (0.32%) had Crohn disease (CD). Patients with IBD were more likely to have a diagnosis of celiac disease (odds ratio [OR], 13.680), with a greater association with CD. Treated patients with UC and with CD, respectively, had a lower risk association with celiac disease compared to those not undergoing IBD treatment, specifically corticosteroids (OR, 0.407 and 0.585), 5-aminosalicylates (OR, 0.124 and 0.127), immunomodulators (OR, 0.385 and 0.425), and anti-tumor necrosis factor drugs (OR, 0.215 and 0.242). There was no lower risk association in the vedolizumab group, but there was a higher risk association among the ustekinumab group.

CONCLUSIONS

In this large dataset, we showed a bidirectional association between celiac disease and IBD that was stronger with CD. Patients with IBD treated using corticosteroids, 5-aminosalicylates, immunomodulators, or anti-tumor necrosis factor drugs had a lower association with celiac disease. Additional studies are required to determine the underlying mechanisms for IBD therapy-related modification of celiac disease incidence.

Clinical Factors Associated With Positive Stool PCR for Gastrointestinal Pathogens in Celiac and Inflammatory Bowel Disease

GOALS

We aimed to identify the clinical factors of celiac disease (CeD) and inflammatory bowel disease (IBD) associated with positive stool gastrointestinal (GI) polymerase chain reaction (PCR) test.

BACKGROUND

Understanding the pattern of enteric infections in CeD and IBD may allow further insight into microbiome-mediated pathogeneses.

STUDY

This was a retrospective study of adult patients (age 18 y or above) with CeD and IBD at a large quaternary care institution. We identified patients with CeD or IBD who underwent stool GIPCR evaluation as outpatients (office visit or at endoscopy) between March 2015 and March 2019. Patients with a negative GIPCR test within the study time frame were randomly chosen as controls (1 : 1). The independent relationship between clinical characteristics and positive GIPCR was evaluated using multivariable logistic regression.

RESULTS

A total of 266 patients met criteria for the study, including 92 (35%) with CeD and 174 (65%) with IBD. On multivariable analysis of factors associated with positive GIPCR test, CeD patients were more likely to have diarrheal presentation of illness [odds ratio (OR): 2.61, 95% confidence interval (CI) 1.05-6.72], experience extraintestinal manifestations (OR: 2.49, 95% CI: 1.01-6.31), and practice a gluten-free diet for at least 5 years (OR: 4.00, 95% CI: 1.36-11.67), relative to those with a negative GIPCR test. IBD patients with positive GIPCR were more likely to be on corticosteroids (OR: 2.23, 95% CI: 1.02-5.4.84), experience extraintestinal manifestations (OR: 2.60, 95% CI: 1.22-5.53), and use proton-pump inhibitors (OR: 4.07, 95% CI: 1.69-9.77).

CONCLUSIONS

Intestinal infections in CeD and IBD are associated with important disease-specific characteristics.

Circulating microRNAs as novel non-invasive biomarkers of paediatric celiac disease and adherence to gluten-free diet

BACKGROUND

Celiac Disease (CD) is a multifactorial autoimmune enteropathy (with a prevalence of approximately 1% worldwide) that exhibits a wide spectrum of clinical, serological and histological manifestations. For the diagnosis of paediatric CD, the gold standard is the combination of serological tests (with high TGA-IgA values greater than 10 times the upper limit of normal) and duodenal biopsy (with a positive TGA-IgA but low titer). Therefore, a diagnostic test that totally excludes an invasive approach has not been discovered so far and the discovery of novel biological markers would represent an undoubted advantage for the diagnosis of CD and prognostic evaluation. MicroRNAs (miRNAs), small non-coding RNAs (18-22 nucleotides) that regulate gene expression at post-transcriptional level and play important roles in many biological processes, represent a novel class of potential disease biomarkers. Their presence in biological fluids (i.e., serum, plasma, saliva, urine) provides the opportunity to employ circulating miRNAs as novel non-invasive biomarkers.

METHODS

In our prospective observational study, we examined the expression of circulating miRNAs in a cohort of CD patients (both at diagnosis and on gluten-free diet, respectively referred as CD and GFD) compared to healthy controls. By small RNA-Seq we discovered a set of circulating miRNAs that were further validated by qPCR with specific assays.

FINDINGS

We found that out of the 13 miRNAs able to discriminate the three groups (i.e., CD, GFD and controls), three of them, namely miR-192-5p, miR-215-5p and miR-125b-5p (alone or in combination), were able to discriminate these three groups with high accuracy and specificity.

INTERPRETATION

Our conclusions emphasize that these circulating miRNAs can be employed not only for the diagnosis of CD patients with a low TGA-IgA titer but also to monitor the adherence to a gluten-free diet by CD patients. In conclusion, we suggest the use of the circulating miRNAs identified in this work as a novel diagnostic and follow-up tool for paediatric CD.

FUNDING

This work was supported by Fondazione Celiachia Onlus (FC) Grant n° 018/FC/2013 and by Italian Ministry of Health (Ricerca Corrente).

Guidelines for the management of patients with Crohn's disease. Recommendations of the Polish Society of Gastroenterology and the Polish National Consultant in Gastroenterology

This paper is an update of the diagnostic and therapeutic recommendations of the National Consultant for Gastroenterology and the Polish Society of Gastroenterology from 2012. It contains 46 recommendations for the diagnosis and treatment, both pharmacological and surgical, of Crohn's disease in adults. The guidelines were developed by a group of experts appointed by the Polish Society of Gastroenterology and the National Consultant in the field of Gastroenterology. The methodology related to the GRADE methodology was used to assess the quality and strength of the available recommendations. The degree of expert support for the proposed statement, assessment of the quality of evidence and the strength of the recommendation was assessed on a 6-point Likert scale. Voting results, quality and strength ratings with comments are included with each statement.

Phenotype and Natural History of Children With Coexistent Inflammatory Bowel Disease and Celiac Disease

BACKGROUND

Adult patients with both inflammatory bowel disease (IBD) and celiac disease (CeD) have peculiar phenotypic features. This study aimed at describing the characteristics and natural history of children with both IBD and CeD.

METHODS

This was a case-control study based on a national registry. Cases included children diagnosed with both IBD and CeD. Two matched IBD controls without CeD, and 2 matched CeD controls were selected for each case. Inflammatory bowel disease phenotype and natural history, comprising growth and pubertal development, were compared between groups.

RESULTS

Forty-nine (1.75%) patients with IBD and CeD were identified out of 2800 patients with IBD. Compared with patients with IBD alone, patients with IBD and CeD presented more frequently with autoimmune diseases (odds ratio, 2.81; 95% CI, 0.97-8.37; P = 0.04). Ileocolonic localization (46.1% vs 73.1%), treatment with azathioprine (46.2% vs 71.2%), and anti-TNF biologics (46.2% vs 69.2%) were less common in patients with Crohn's disease and CeD than in patients with Crohn's disease alone. Patients with ulcerative colitis and CeD had an increased risk of colectomy despite similar medical treatments compared with patients with ulcerative colitis alone (13.0% vs 0%). Pubertal delay was more common in patients with IBD and CeD compared with patients with IBD alone (14.9% vs 3.2%; odds artio, 5.24; 95% CI, 1.13-33.0; P = 0.02) and CeD alone (14.9% vs 1.1%; P = 0.002).

CONCLUSIONS

Children with IBD and CeD may have peculiar features with a higher risk for autoimmune diseases, colectomy, and pubertal delay compared with IBD alone.

Molecular and Structural Parallels between Gluten Pathogenic Peptides and Bacterial-Derived Proteins by Bioinformatics Analysis

Gluten-related disorders (GRDs) are a group of diseases that involve the activation of the immune system triggered by the ingestion of gluten, with a worldwide prevalence of 5%. Among them, Celiac disease (CeD) is a T-cell-mediated autoimmune disease causing a plethora of symptoms from diarrhea and malabsorption to lymphoma. Even though GRDs have been intensively studied, the environmental triggers promoting the diverse reactions to gluten proteins in susceptible individuals remain elusive. It has been proposed that pathogens could act as disease-causing environmental triggers of CeD by molecular mimicry mechanisms. Additionally, it could also be possible that unrecognized molecular, structural, and physical parallels between gluten and pathogens have a relevant role. Herein, we report sequence, structural and physical similarities of the two most relevant gluten peptides, the 33-mer and p31-43 gliadin peptides, with bacterial pathogens using bioinformatics going beyond the molecular mimicry hypothesis. First, a stringent BLASTp search using the two gliadin peptides identified high sequence similarity regions within pathogen-derived proteins, e.g., extracellular proteins from Streptococcus pneumoniae and Granulicatella sp. Second, molecular dynamics calculations of an updated α-2-gliadin model revealed close spatial localization and solvent-exposure of the 33-mer and p31-43 peptide, which was compared with the pathogen-related proteins by homology models and localization predictors. We found putative functions of the identified pathogen-derived sequence by identifying T-cell epitopes and SH3/WW-binding domains. Finally, shape and size parallels between the pathogens and the superstructures of gliadin peptides gave rise to novel hypotheses about activation of innate immunity and dysbiosis. Based on our structural findings and the similarities with the bacterial pathogens, evidence emerges that these pathologically relevant gluten-derived peptides could behave as non-replicating pathogens opening new research questions in the interface of innate immunity, microbiome, and food research.

Glycine Attenuates Citrobacter rodentium-Induced Colitis by Regulating ATF6-Mediated Endoplasmic Reticulum Stress in Mice

SCOPE

Inflammatory bowel disease (IBD) is an inflammatory gastrointestinal disorder in which endoplasmic reticulum (ER) stress and dysbiosis of the intestinal microbiota are implicated. Glycine supplementation is reported to reduce inflammatory responses in experimental colitis. However, the underlying mechanisms responsible for the beneficial effects remain unclear.

METHODS AND RESULTS

Female C57BL/6 mice are orally administered with glycine (3.5 or 5.2 g kg-1 body weight) for 14 continuous days. On day 8 post-glycine supplementation, the mice are orally inoculated with 2 × 109 CFU Citrobacter rodentium (C. rodentium). The results show that glycine alleviates C. rodentium-induced body weight loss, increased disease activity index and spleen weight, colon length shortening, and colonic hyperplasia. Glycine suppresses the activation and infiltration of inflammatory cells, and secretion of pro-inflammatory cytokines in the colon tissues. The apoptosis of colon epithelial cells is also abrogated by glycine, which is associated with the inactivation of activating transcription factor 6α (ATF6α)-C/EBP homologous protein (CHOP) signaling. In addition, glycine administration increases α diversity, restores β diversity, and abolishes the reduction in Lactobacillus, Bifidobacterium, Alistipes, Turicibacter, and Alloprevotella in the colon.

CONCLUSIONS

Glycine supplementation is a nutritional strategy that may ameliorate C. rodentium-induced colitis by regulating ATF6α-CHOP-mediated ER stress and enhancing the abundance of Lactobacillus.

Sarcopenia, severe anxiety and increased C-reactive protein are associated with severe fatigue in patients with inflammatory bowel diseases

Patients with inflammatory bowel disease (IBD) report fatigue more frequently than healthy population, but the precise mechanisms underlying its presence are unknown. This study aimed to evaluate the prevalence of fatigue in IBD and its relation with potential causative factors. A survey on fatigue, depression, anxiety, sleep disorders, and the presence of sarcopenia and malnutrition, was sent by email to 244 IBD outpatients of the Gastroenterology Unit of Academic Hospital of Padua. Demographics and clinical data, including the levels of fecal calprotectin (FC) and C-reactive protein (CRP), and current pharmacological treatments were obtained from patients' medical records. Ninety-nine (40.5%) subjects answered the survey. Ninety-two (92.9%) patients reported fatigue, with sixty-six having mild to moderate fatigue and twenty-six severe fatigue. Multivariate analysis showed that abnormal values of CRP (OR 5.1), severe anxiety (OR 3.7) and sarcopenia (OR 4.4) were the factors independently associated with severe fatigue. Fatigue has a high prevalence in subject affected by IBD. Subjects with altered CRP, sarcopenia and severe anxiety appear more at risk of severe fatigue.

Dual threat of comorbidity of celiac disease and systemic lupus erythematosus

Celiac disease (CD) is a chronic immune-mediated intestinal disease that is characterized by production of autoantibodies directed against the small intestine. The main clinical manifestations of CD are typically defined as those related to indigestion and malabsorption. These manifestations include unexplained diarrhea or constipation, abdominal pain, bloating, weight loss, anemia, failure-to-thrive in children, and decreased bone density. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by heterogeneous clinical manifestations, which may also involve the gastrointestinal tract. Comorbidity of CD and SLE is rare, and the overlapping symptoms and nonspecific clinical presentation may pose a diagnostic challenge to clinicians. We report here a case of SLE with CD, which mainly manifested as recurrent diarrhea, uncorrectable electrolyte disorders, and severe malnutrition. Through review, we hope to further improve our understanding and diagnostic level of this combination of diseases.

An unusual case of chronic abdominal pain: an association between Celiac disease and Crohn's disease

Inflammatory bowel diseases (IBD) and Celiac disease (CeD) are immune-mediated gastrointestinal diseases with incompletely understood etiology. Both diseases show a multifactorial origin with a complex interplay between genetic, environmental factors, and some components of the commensal microbiota. The coexistence of celiac disease with Crohn's disease is rarely reported in the literature. Here, we report a case of a 13-year-old Syrian male who presented with a history of abdominal pain, anorexia and pallor. CeD and Crohn's disease was documented on gastrointestinal endoscopy and histological study. The patient was treated with a gluten-free, low fiber, high caloric diet, and a course of oral corticosteroids with an improvement in growth rate and abdominal pain.

Genetic polymorphism of HLA-G gene (G*01:03, G*01:04, and G*01:05N) in Iraqi patients with inflammatory bowel disease (ulcerative colitis and Crohn’s disease)

Background

Human leukocyte antigen-G (HLA-G) has been proposed to influence susceptibility to inflammatory bowel disease (IBD). Therefore, the genetic association between HLA-G alleles and two clinical phenotypes of IBD (ulcerative colitis [UC] and Crohn’s disease [CD]) was evaluated in Iraqi patients. A case-control study was performed on 50 UC and 50 CD patients and 100 healthy controls (HC). Three HLA-G alleles (G*01:03, G*01:04, and G*01:05N) were determined using sequence-specific polymerase chain reaction assay followed by product digestion with restriction endonucleases (Hinf-I, BseR-I, and PpuM-I, respectively).

Results

The G*01:03 allele was not detected in IBD patients (UC and CD) or HC, while G*01:04 and G*01:05N alleles showed polymorphic frequencies. The allele G*01:04 was significantly associated with susceptibility to UC (odds ratio [OR] = 2.55; 95% confidence interval [CI] = 1.27–5.13; corrected probability [pc] = 0.018) and CD (OR = 4.45; 95% CI = 2.11–9.41; pc < 0.001). The allele G*01:05N was also associated with increased risk of UC (OR = 4.17; 95% CI = 1.32–13.21; pc = 0.032) and CD (OR = 4.75; 95% CI = 1.53–14.78; pc = 0.014). These associations were more pronounced in IBD (UC + CD), and a significantly increased risk for IBD was found with the alleles G*01:04 (OR = 3.32; 95% CI = 1.86–5.95; pc < 0.001) and G*01:05N (OR = 4.46; 95% CI = 1.59–12.47; pc = 0.008). A stratification of IBD patients according to some demographic and clinical characteristics revealed that frequencies of both alleles showed no significant differences between the subgroups of patients in each stratum. Soluble HLA-G was not influenced by HLA-G alleles in patients or HC. UC was an exception, and the presence of G*01:04 allele was associated with a significantly higher mean of soluble HLA-G compared to patients without the allele (189.6 ± 24.0 vs. 168.6 ± 27.2 ng/mL; p = 0.033).

Conclusion

This study indicated that HLA-G*01:04 and HLA-G*01:05N alleles may influence susceptibility to UC and CD in Iraqi patients.

Risk Factors Associated With Hospital Readmission and Costs for Pouchitis

Background

Pouchitis is the most common long-term complication in patients with restorative proctocolectomy and ileal pouch-anal anastomosis. This study aimed to identify readmission rates for pouchitis and risk factors associated with readmissions in an extensive national database.

Methods

We performed a retrospective analysis using the National Readmission Database to determine if patient demographics and clinical characteristics were predictors of hospital readmission within 30 days for adult patients (age >18 years) discharged with a principal diagnosis of pouchitis (ICD-9 code-569.71) from January 2013 to December 2013. Both univariable and multivariable analyses were performed to assess factors associated with 30-day readmission.

Results

A total of 1538 patients with pouchitis who were discharged alive were identified. 10.2% [95% confidence interval: 7.6, 12.7] of these were readmitted within 30 days of discharge. The average days to readmission were 18.6 ± 1.01. Multivariable analysis of risk factors associated with readmission showed older age as a protective factor for readmission [odds ratio (OR) = 0.88 (0.81, 0.96); P < 0.005]. Sex and the presence of permanent ileostomy were not associated with readmission in patients with pouchitis. The length of stay during readmissions was associated with postoperative wound infection [OR = 7.7 (94.0, 11.30); P < 0.001], ileus [OR = 4.5 (1.6, 7.4); P < 0.002], permanent ileostomy [OR = 3.7 (1.7, 5.7); P < 0.001], and long-term use of nonsteroidal anti-inflammatory drugs [OR = 3.2 (1.06, 5.3); P < 0.003].

Conclusions

Readmissions in pouchitis patients are frequent. Long-term use of nonsteroidal anti-inflammatory drugs, ileus, permanent ileostomy, and postoperative wound infection is associated with increased length of stay in readmissions.

Impact of 2'-Fucosyllactose on Gut Microbiota Composition in Adults with Chronic Gastrointestinal Conditions: Batch Culture Fermentation Model and Pilot Clinical Trial Findings

Intestinal dysbiosis has been described in patients with certain gastrointestinal conditions including irritable bowel syndrome (IBS) and ulcerative colitis. 2′-fucosyllactose (2′-FL), a prebiotic human milk oligosaccharide, is considered bifidogenic and butyrogenic. To assess prebiotic effects of 2′-FL, alone or in combination with probiotic strains (potential synbiotics), in vitro experiments were conducted on stool from healthy, IBS, and ulcerative colitis adult donors. In anaerobic batch culture fermenters, Bifidobacterium and Eubacterium rectale-Clostridium coccoides counts, and short-chain fatty acids (SCFAs) including butyrate increased during fermentation with 2′-FL and some of the 2′-FL/probiotic combinations. In a subsequent open-label pilot trial, the effect of a 2′-FL-containing nutritional formula was evaluated in twelve adults with IBS or ulcerative colitis. Gastrointestinal Quality of Life Index (GIQLI) total and gastrointestinal symptoms domain scores, stool counts of Bifidobacterium and Faecalibacterium prausnitzii, and stool SCFAs including butyrate, increased after six weeks of intervention. Consistent with documented effects of 2′-FL, the batch culture fermentation experiments demonstrated bifidogenic and butyrogenic effects of 2′-FL during fermentation with human stool samples. Consumption of the 2′-FL-containing nutritional formula by adults with IBS or ulcerative colitis was associated with improvements in intra- and extra-intestinal symptoms, and bifidogenic and butyrogenic effects.

Network Analysis of Common Genes and Transcriptional Factors between Celiac Disease and Inflammatory Bowel Diseases

BACKGROUND

Understanding the associations among different disorders remarkably improves their diagnosis and treatments. Celiac disease is the most complicated and prevalent form of immune-mediated diseases. On the other hand, inflammatory bowel diseases lead to inflammation of the intestine with an unknown cause. Although inflammatory bowel diseases have been often thought of as an autoimmune disorder, they can be triggered by whatever that can lead to the inflammation in the whole bowel. Henceforth, both aforementioned diseases are related to autoimmune attacks and cause a sort of inflammatory event, which exploring trade-off among them supposedly will lead to discovering important genes and, in turn, to the possible common therapeutic protocols. In the current study, we aimed to determine the correlation between the common genes in celiac disease and inflammatory bowel diseases.

METHODS

314 and 851 genes correlated with celiac disease and inflammatory bowel diseases respectively extracted from DisGeNET were subjected to an in-silico data analysis framework to mine prognosticates genes and the associated pathways.

RESULTS

149 shared genes between these diseases regulated by highlighted transcription factors NFKB1, IRF1, STAT1, HSF1, GATA3 were characterized as discriminating molecules, which by further screening were enriched in pathways mostly involved in apoptosis, T cell activation, and cytokine, chemokine, and interleukin signaling.

CONCLUSION

We observed that the identified common genes were associated with a wide range of pathogenic mechanisms underlying these diseases.

Genome-wide genetic links between amyotrophic lateral sclerosis and autoimmune diseases

BACKGROUND

Epidemiological and clinical studies have suggested comorbidity between amyotrophic lateral sclerosis (ALS) and autoimmune disorders. However, little is known about their shared genetic architecture.

METHODS

To examine the relation between ALS and 10 autoimmune diseases, including asthma, celiac disease (CeD), Crohn's disease (CD), inflammatory bowel disease (IBD), multiple sclerosis (MS), psoriasis, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), and ulcerative colitis (UC), and identify shared risk loci, we first estimated the genetic correlation using summary statistics from genome-wide association studies, and then analyzed the genetic enrichment leveraging the conditional false discovery rate statistical method.

RESULTS

We identified a significant positive genetic correlation between ALS and CeD, MS, RA, and SLE, as well as a significant negative genetic correlation between ALS and IBD, UC, and CD. Robust genetic enrichment was observed between ALS and CeD and MS, and moderate enrichment was found between ALS and UC and T1D. Thirteen shared genetic loci were identified, among which five were suggestively significant in another ALS GWAS, namely rs3828599 (GPX3), rs3849943 (C9orf72), rs7154847 (G2E3), rs6571361 (SCFD1), and rs9903355 (GGNBP2). By integrating cis-expression quantitative trait loci analyses in Braineac and GTEx, we further identified GGNBP2, ATXN3, and SLC9A8 as novel ALS risk genes. Functional enrichment analysis indicated that the shared risk genes were involved in four pathways including membrane trafficking, vesicle-mediated transport, ER to Golgi anterograde transport, and transport to the Golgi and subsequent modification.

CONCLUSIONS

Our findings demonstrate a specific genetic correlation between ALS and autoimmune diseases and identify shared risk loci, including three novel ALS risk genes. These results provide a better understanding for the pleiotropy of ALS and have implications for future therapeutic trials.

Causal Estimation with Functional Confounders

Causal inference relies on two fundamental assumptions: ignorability and positivity. We study causal inference when the true confounder value can be expressed as a function of the observed data; we call this setting estimation with functional confounders (EFC). In this setting ignorability is satisfied, however positivity is violated, and causal inference is impossible in general. We consider two scenarios where causal effects are estimable. First, we discuss interventions on a part of the treatment called functional interventions and a sufficient condition for effect estimation of these interventions called functional positivity. Second, we develop conditions for nonparametric effect estimation based on the gradient fields of the functional confounder and the true outcome function. To estimate effects under these conditions, we develop Level-set Orthogonal Descent Estimation (LODE). Further, we prove error bounds on LODE's effect estimates, evaluate our methods on simulated and real data, and empirically demonstrate the value of EFC.

Role of PD-L1 in Gut Mucosa Tolerance and Chronic Inflammation

The gastrointestinal (GI) mucosa is among the most complex systems in the body. It has a diverse commensal microbiome challenged continuously by food and microbial components while delivering essential nutrients and defending against pathogens. For these reasons, regulatory cells and receptors are likely to play a central role in maintaining the gut mucosal homeostasis. Recent lessons from cancer immunotherapy point out the critical role of the B7 negative co-stimulator PD-L1 in mucosal homeostasis. In this review, we summarize the current knowledge supporting the critical role of PD-L1 in gastrointestinal mucosal tolerance and how abnormalities in its expression and signaling contribute to gut inflammation and cancers. Abnormal expression of PD-L1 and/or the PD-1/PD-L1 signaling pathways have been observed in the pathology of the GI tract. We also discuss the current gap in our knowledge with regards to PD-L1 signaling in the GI tract under homeostasis and pathology. Finally, we summarize the current understanding of how this pathway is currently targeted to develop novel therapeutic approaches.

Association Between Inflammatory Bowel Diseases and Celiac Disease: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

There is controversy over the association between celiac disease (CeD) and inflammatory bowel diseases (IBD). We performed a systematic review and meta-analysis to assess evidence for an association between CeD and IBD.

METHODS

We searched databases including MEDLINE, EMBASE, CENTRAL, Web of Science, CINAHL, DARE, and SIGLE through June 25, 2019 for studies assessing the risk of CeD in patients with IBD, and IBD in patients with CeD, compared with controls of any type. We used the Newcastle-Ottawa Scale to evaluate the risk of bias and GRADE to assess the certainty of the evidence.

RESULTS

We identified 9791 studies and included 65 studies in our analysis. Moderate certainty evidence found an increased risk of CeD in patients with IBD vs controls (risk ratio [RR] 3.96; 95% confidence interval [CI] 2.23-7.02) and increased risk of IBD in patients with CeD vs controls (RR 9.88; 95% CI 4.03-24.21). There was low-certainty evidence for the risk of anti-Saccharomyces antibodies, a serologic marker of IBD, in patients with CeD vs controls (RR 6.22; 95% CI 2.44-15.84). There was low-certainty evidence for no difference in risk of HLA-DQ2 or DQ8 in patients with IBD vs controls (RR 1.04; 95% CI 0.42-2.56), and very low-certainty evidence for an increased risk of anti-tissue transglutaminase in patients with IBD vs controls (RR 1.52; 95% CI 0.52-4.40). Patients with IBD had a slight decrease in risk of anti-endomysial antibodies vs controls (RR 0.70; 95% CI 0.18-2.74), but these results are uncertain.

CONCLUSIONS

In a systematic review and meta-analysis, we found an increased risk of IBD in patients with CeD and increased risk of CeD in patients with IBD, compared with other patient populations. High-quality prospective cohort studies are needed to assess the risk of CeD-specific and IBD-specific biomarkers in patients with IBD and CeD.

Prevalence of Celiac Disease in Children and Adolescents With Inflammatory Bowel Disease

Introduction

The association between inflammatory bowel disease (IBD) - particularly its two main subtypes, ulcerative colitis (UC) and Crohn’s disease (CD) - and celiac disease (CeD) has been attributed to an overlap in the mechanism of immune dysregulation that characterizes these conditions. Owing to the paucity of studies that have explored this condition in pediatric patients, we examined the prevalence of CeD in children with IBD.

Materials and methods

This is a cross-sectional study of children aged two to 18 years with IBD that were diagnosed between 2016 and 2018. Clinical, demographic, laboratory, and endoscopic data were analysed. Serology for CeD measured the immunoglobulin A tissue transglutaminase (IgA-tTG) antibodies, and the diagnosis was confirmed histologically through small bowel biopsies.

Results

The study included 101 patients with IBD (83.2% with UC and 16.8% with CD). The mean age was 8.7±4.0 years. Males constituted 59.4% of the cohort, and only 3% had perianal disease. Ileocolonic involvement was reported in 64.7% and non-stricturing and non-penetrating behaviour in 76.7% of CD patients. Pancolitis constituted 45.2% of UC patients. Ten patients (9.9%) had positive serology based on IgA-tTG antibodies, three (approximately 3%) had CeD based on biopsy findings, two patients (2%) had CD, and one patient (1%) had UC. Patients with confirmed CeD had a significantly higher frequency of symptoms of gaseous sensation and bloating (P=0.003) and abdominal distension (P=0.04).

Conclusions

The prevalence of CeD in Egyptian children with IBD is higher than previously reported in a number of similar studies. Abdominal bloating and gaseous sensation were identified as associated symptoms.

The expression levels of CHI3L1 and IL15Rα correlate with TGM2 in duodenum biopsies of patients with celiac disease

OBJECTIVE AND DESIGN

Celiac disease (CD) is an intestinal inflammatory disorder of the small intestine. Gliadins are a component of gluten and there are three main types (α, γ, and ω). Recent studies indicate that gliadin peptides are able to activate an innate immune response. IL15 is a major mediator of the innate immune response and is involved in the early alteration of CD mucosa. The chitinase molecules are highly expressed by the innate immune cells during the inflammatory processes.

MATERIAL OR SUBJECTS

We analyzed several microarray datasets of PBMCs and duodenum biopsies of CD patients and healthy control subjects (HCs). We verified the modulation CHI3L1 in CD patients and correlated the expression levels to the IL15, IL15Rα, TGM2, IFNγ, and IFNGR1/2. Duodenal biopsy samples belonged to nine active and nine treated children patients (long-term effects of gliadin), and 17 adult CD patients and 10 adults HCs. We also selected 169 samples of PBMCs from 127 CD patients on adherence to a gluten-free diet (GFD) for at least 2 years and 44 HCs.

RESULTS

Our analysis showed that CHI3L1 and IL15Rα were significantly upregulated in adult and children's celiac duodenum biopsies. In addition, the two genes were correlated significantly both in children than in adults CD duodenum biopsies. No significant modulation was observed in PBMCs of adult CD patients compared to the HCs. The correlation analysis of the expression levels of CHI3L1 and IL15Rα compared to TGM showed significant values both in adults and in children duodenal biopsies. Furthermore, the IFNγ expression levels were positively correlated with CHI3L1 and IL15Rα. Receiver operating characteristic (ROC) analysis confirmed the diagnostic ability of CHI3L1 and IL15Rα to discriminate CD from HCs.

CONCLUSION

Our data suggest a role for CHI3L1 underlying the pathophysiology of CD and represent a starting point aiming to inspire new investigation that proves the possible use of CHI3L1 as a diagnostic factor and therapeutic target.

A food pyramid, based on a review of the emerging literature, for subjects with inflammatory bowel disease

Emerging literature suggests that diet plays an important modulatory role in inflammatory bowel disease (IBD) through the management of inflammation and oxidative stress. The aim of this narrative review is to evaluate the evidence collected up till now regarding optimum diet therapy for IBD and to design a food pyramid for these patients. The pyramid shows that carbohydrates should be consumed every day (3 portions), together with tolerated fruits and vegetables (5 portions), yogurt (125ml), and extra virgin olive oil; weekly, fish (4 portions), white meat (3 portions), eggs (3 portions), pureed legumes (2 portions), seasoned cheeses (2 portions), and red or processed meats (once a week). At the top of the pyramid, there are two pennants: the red one means that subjects with IBD need some personalized supplementation and the black one means that there are some foods that are banned. The food pyramid makes it easier for patients to decide what they should eat.

Link Between Celiac Disease and Inflammatory Bowel Disease

GOAL

The aim of this analysis was to assess in patients with inflammatory bowel disease (IBD) the risk of celiac disease and in celiac disease patients the risk of IBD.

BACKGROUND

Previous studies report a possible association between IBD and celiac disease; however, this link is controversial.

STUDY

Using the search terms "inflammatory bowel disease" and "celiac disease," we identified initially 1525 publications. In total 27 studies met inclusion criteria. Proportions and 95% confidence intervals (CIs) for the prevalence of IBD in celiac disease and vice versa were compared with published prevalence rates for the respective geographic regions.

RESULTS

We included 41,482 adult IBD patients (20,357 with Crohn's disease; 19,791 with ulcerative colitis; and 459 patients with celiac disease). Overall, in IBD patients the prevalence of celiac disease was 1110/100,000 (95% CI, 1010-1210/100,000) as compared with a prevalence of 620/100,000 (95% CI, 610-630/100,000) in the respective populations (odds ratio, 2.23; 95% CI, 1.99-2.50). In contrast, in patients with celiac disease, 2130/100,000 had IBD (95% CI, 1590-2670/100,000) as compared with 260/100,000 (95% CI, 250/100,000-270/100,000) in the respective populations (odds ratio, 11.10; 95% CI, 8.55-14.40). This effect was not different for ulcerative colitis and Crohn's disease. Although there was no evidence for publication bias for celiac disease in IBD, the funnel plot suggested that the association between IBD in celiac disease might be influenced by publication bias.

CONCLUSIONS

The data are consistent with the notion that celiac disease is a risk factor for IBD and to lesser degree patients with IBD have an increased risk of celiac disease.

Oxidative stress, DNA stability and evoked inflammatory signaling in young celiac patients consuming a gluten-free diet

PURPOSE

Celiac disease (CD) is a multifactorial, autoimmune, gluten-sensitive inflammatory disorder of the small intestine. Taking into account the pathogenesis of CD, a strict gluten-free diet (GFD) is the only treatment able to restore epithelium integrity and eliminate complications. The current study was designed to assess whether the use of a GFD is sufficient for maintaining a correct oxidative/antioxidant balance and ameliorating the evoked inflammatory signaling in young patients with CD.

METHODS

The study covered 80 children, aged between 7 and 18 years, attending the Gastroenterology Service of the Gastroenterology, Hepatology and Child Nutrition Service from the Virgen de las Nieves Hospital in Granada. Children with CD diagnosed were included in the celiac group who followed a strict GFD for 2 years (n = 40) and the control group (n = 40) included healthy children, with negative serological screening. Soluble superoxide dismutase 1 and 2, total antioxidant status, 8-hydroxy-2'-deoxyguanosine, cortisol, melatonin and inflammatory parameters in plasma, 15-F2t-isoprostanes in urine, and DNA breaks in peripheral blood lymphocytes were analysed.

RESULTS

No differences were found in oxidative stress between CD patients and controls; however, IFN-γ, IL-1α, IP-10 and TNF-β were higher in the CD patients. VEGF was also higher than in the control group.

CONCLUSION

The GFD in the CD patients is enough to reduce the oxidative stress; however, in the case of the inflammatory signaling, the initial exposure to gluten prior to stablish the GFD is strong enough to induce an inflammatory state which is maintained (even when consuming the GFD); meanwhile the increase in VEGF recorded in the CD group could be a compensatory mechanism to restore the damaged mucosa and duodenal villous atrophy, due to its role in endothelial activation and generation of new functional and stable vascular networks.

Haemorheological and haemostatic alterations in coeliac disease and inflammatory bowel disease in comparison with non-coeliac, non-IBD subjects (HERMES): a case-control study protocol

INTRODUCTION

Haemorheological and haemostatic changes predispose to the development of arterial and venous thrombotic events; however, limited information is available on the status of these changes in coeliac disease (CeD) and inflammatory bowel disease (IBD). In this study, we aim to describe the haemorheological and haemostatic profiles of CeD and IBD patients in a Hungarian cohort of patients to investigate whether any alterations contribute to elevated thrombotic risk.

METHODS AND ANALYSIS

This is a case-control study involving newly diagnosed and followed CeD and IBD patients with age-matched and sex-matched non-CeD, non-IBD subjects with an allocation ratio of 1:1:1.After informed consent is obtained, a detailed medical history will be collected, including venous and arterial thrombotic risk factors and medications. Symptoms in CeD patients will be assessed with the Gastrointestinal Symptoms Rating Scale, and disease activity in IBD patients will be determined by disease-specific scores. Dietary adherence will be assessed among CeD patients with a thorough interview together with a measurement of self-reported adherence, dietary knowledge and urine analysis (detection of gluten immunogenic peptides). In addition to routine laboratory parameters, haemorheological (ie, erythrocyte deformability and aggregation, viscosity of whole blood and plasma) and haemostatic parameters (eg, protein C, protein S and antithrombin) with immunological indicators (ie, coeliac-specific serology and antiphospholipid antibodies) will be measured from venous blood for every participant.Primary and secondary outcomes will be haemorheological and haemostatic parameters, respectively. Univariate and multivariate statistics will be used to compare CeD and IBD patients to control subjects. Subgroup analysis will be performed by disease type in IBD, (Crohn's disease and ulcerose colitis), dietary adherence in CeD, and disease activity in IBD and CeD.

ETHICS AND DISSEMINATION

The study was approved by the Regional and Local Research Ethics Committee, University of Pécs (Ref. No. 6917). Findings will be disseminated at research conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN49677481.