Global Prevalence of Celiac Disease: Systematic Review and Meta-analysis

Interaction between Gut Microbiota and Celiac Disease: From Pathogenesis to Treatment

Celiac disease (CD) is a common systemic disorder that results from an abnormal response of human immunity to gluten intake, affecting the small intestine. In individuals who carry a genetic susceptibility, CD is triggered by environmental factors, including viral infections and dysbiosis of the gut microbiota. The gut microbiome is essential in controlling the immune system, and recent findings indicate that changes in the gut microbiome may contribute to various chronic immune disorders, such as CD through mechanisms that still require further exploration. Some bacteria exhibit epitopes that mimic gliadin and may enhance an immune response in the host. Other bacteria, including Pseudomonas aeruginosa, may work in conjunction with gluten to trigger and escalate intestinal inflammation. The microbiota may also directly influence antigen development through the production of immunogenic or tolerogenic gluten peptides or directly influence intestinal permeability through the release of zonulin. Finally, the gut microbiome can impact intestinal inflammation by generating proinflammatory or anti-inflammatory cytokines and metabolites. It is crucial to consider the impact of genetic factors (specifically, HLA-DQ haplotypes), perinatal elements such as birth mode, type of infant feeding, and antibiotic and infection exposure on the composition of the early intestinal microbiome. According to the available studies, the gut microbiome alterations associated with CD tend to exhibit a decreased presence of beneficial bacteria, including some anti-inflammatory Bifidobacterium species. However, some controversy remains as some reports have found no significant differences between the gut microbiomes of individuals with and without CD. A better understanding of the gut microbiome’s role in the development of CD would greatly benefit both prevention and treatment efforts, especially in complicated or treatment-resistant cases. Here, we have attempted to summarize the available evidence on the relationship between the gut microbiota and CD, with a particular focus on potential therapeutic targets.

Celiac Disease and Cardiovascular Risk: A Retrospective Case-Control Study

Background: The association of celiac disease (CD) with premature atherosclerosis, including increased carotid artery intima-media thickness and cardiovascular disease (CVD), is controversial. The aim of this study was to investigate this relationship. Methods: Clinical records of patients from Northern Sardinia referred to the Gastroenterology section of the Department of Medicine, University of Sassari, Italy, were analyzed. Unadjusted and adjusted odds ratios (ORs) for CVD with their 95% confidence intervals (CIs) were calculated according to established risk factors, including age, sex, diabetes, dyslipidemia, overweight/obesity, blood hypertension, and cigarette smoking, as well as a possible risk factor such as H. pylori infection. Results: In a total of 8495 patients (mean age 52.1 ± 17.3 years; 64.7% females), 2504 reported a diagnosis of CVD and 632 of CD. Logistic regression analysis showed a significantly reduced risk of CVD among patients with CD (OR 0.30, 95% CI 0.22–0.41). Moreover, the long duration of the gluten-free diet (GFD) was able to lower the risk of CVD in celiac patients. Finally, CD significantly decreased the frequency of carotid plaques (11.8% vs. 40.1%, p < 0.001). Conclusions. Our retrospective study demonstrated that CD reduces the risk of CVD in general and more specifically of carotid lesions after adjusting for potential confounders, especially in those on GFD for a long time.

Celiac disease and risk of microscopic colitis: A nationwide population-based matched cohort study

BACKGROUND

An association has been reported between celiac disease (CD) and microscopic colitis (MC). However, large, population-based cohort studies are rare.

OBJECTIVE

To systematically examine the association between CD and MC in a large, nationwide cohort.

METHODS

We conducted a nationwide population-based matched cohort study in Sweden of 45,138 patients with biopsy-verified CD (diagnosed in 1990-2016), 223,149 reference individuals, and 51,449 siblings of CD patients. Data on CD and MC were obtained from all (n = 28) pathology departments in Sweden. Adjusted hazard ratios (aHRs) were calculated using Cox regression.

RESULTS

During follow-up, 452 CD patients and 197 reference individuals received an MC diagnosis (86.1 vs. 7.5 per 100,000 person-years). This difference corresponded to an aHR of 11.6 (95% confidence interval [CI] = 9.8-13.8) or eight extra MC cases in 1000 CD patients followed up for 10 years. Although the risk of MC was highest during the first year of follow-up (aHR 35.2; 95% CI = 20.1-61.6), it remained elevated even after 10 years (aHR 8.1; 95% CI = 6.0-10.9). Examining MC subtypes lymphocytic colitis (LC) and collagenous colitis (CC) separately, the aHR was 12.4 (95% CI = 10.0-15.3) for LC and 10.2 (95% CI = 7.7-13.6) for CC. MC was also more common before CD (adjusted odds ratio [aOR] = 52.7; 95% CI = 31.4-88.4). Compared to siblings, risk estimates decreased but remained elevated (CD and later MC: HR = 6.2; CD and earlier MC: aOR = 7.9).

CONCLUSION

Our study demonstrated a very strong association of MC with CD with an increased risk of future and previous MC in CD patients. The magnitude of the associations underscores the need to consider the concomitance of these diagnoses in cases in which gastrointestinal symptoms persist or recur despite a gluten-free diet or conventional MC treatment. The comparatively lower risk estimates in sibling comparisons suggest that shared genetic and early environmental factors may contribute to the association between CD and MC.

Celiac Disease Presenting in a Community-Based Gastroenterology Practice: Obesity and Bone Disease Are Common

BACKGROUND

The description of the clinical presentation of celiac disease (CeD) has usually come from studies at referral centers. Data about CeD presentation in the community are sparse.

AIMS

We aim to describe the clinical presentation of patients with biopsy-proven CeD at a community-based adult gastroenterology practice and compare it to a referral center.

METHODS

We performed a retrospective study of two cohorts of patients diagnosed with CeD between 2000-2007 (n = 117) and 2013-2016 (n = 91) in a community practice, and a third cohort (n = 188) diagnosed between 2000 and 2007 in a tertiary referral center. The clinical presentation, body mass index, tissue-transglutaminase levels, DEXA scan, vitamin D levels, and vaccine recommendations were assessed.

RESULTS

Celiac disease presentation changed over time in the two community cohorts. Recently, fewer patients presented with diarrhea and anemia, but constipation and neurologic symptoms were more common. The most recent cohort had a higher proportion of patients who were overweight or obese than the first cohort. However, the body mass index in both community cohorts was higher than in the tertiary referral center. The frequency of osteopenia and osteoporosis was high in both community cohorts. The tertiary referral center patients were younger, presented with a higher proportion of diarrhea and a lower body mass index.

CONCLUSIONS

The clinical presentation of CeD differs between the community setting and a tertiary referral center. Patients with CeD presenting to the community setting tended to be older, overweight, and to have a high proportion of mineral bone disease.

Uncovering the NAFLD burden in people living with HIV from high- and middle-income nations: a meta-analysis with a data gap from Subsaharan Africa

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) has become a significant concern among people living with HIV (PLHIV), albeit its burden remains unclear. The primary objective of this systematic review (SR) and meta-analysis (MA) was to estimate the prevalence of NAFLD and significant fibrosis in PLHIV. The secondary objective was to determine the risk factors for NAFLD among PLHIV.

METHODS

We searched MEDLINE and Scopus from inception to 30 December 2022 for peer-reviewed studies that included PLHIV and reported the prevalence of NAFLD. MA of proportions was used to estimate the pooled prevalence of NAFLD and significant fibrosis. MA of pre-calculated effect estimates examined risk factors for NAFLD in PLHIV.

RESULTS

We included 24 articles published between 2009 and 2022, encompassing 6326 PLHIV. The pooled prevalence of NAFLD was 38% (95% CI: 31-45%) with high heterogeneity (I² = 96.3%). The pooled prevalence of significant fibrosis was 13% (95% CI: 8-18%) with high heterogeneity (I² = 92.09%). Subgroup analyses showed a NAFLD prevalence of 40% (95% CI: 24-57%) in the United States, 33% (95% CI: 31-36) in Asia, 42% (95% CI: 24-61%) in Europe and 33% (95% CI: 29-37) in South America. When stratifying by income level, NAFLD was 39% (95% CI: 31-48) prevalent in PLHIV from high-income economies and 34% in both upper-middle-income (95% CI: 31-37%) and lower-middle-income economies (95% CI: 28-41%). Higher body mass index (BMI) (OR = 1.32, 95% CI: 1.13-1.55; I² = 89.9%), increasing triglycerides (OR = 1.48, 95% CI: 1.22-2.79; I² = 27.2%) and dyslipidaemia (OR = 1.89, 95% CI: 1.32-2.71; I² = 15.5%) were all associated with higher risk-adjusted odds of NAFLD in PLHIV.

DISCUSSION

The burden of NAFLD and significant fibrosis in PLHIV is significant. Therefore, targeted efforts to screen and diagnose NAFLD in this population are needed. Health services for PLHIV could include ways to target NAFLD risk factors, screen for liver disease and implement interventions to treat those with significant fibrosis or more advanced stages of liver disease. Taking no action to address NAFLD in PLHIV should not be an option.

CONCLUSIONS

This SR and MA found a 38% NAFLD and 13% significant fibrosis prevalence in PLHIV. Increasing triglyceride levels, higher BMI values and dyslipidaemia were associated with higher risk-adjusted odds of NAFLD among PLHIV.

Automated analysis of small intestinal lamina propria to distinguish normal, Celiac Disease, and Non-Celiac Duodenitis biopsy images

BACKGROUND AND OBJECTIVE

Celiac Disease (CD) is characterized by gluten intolerance in genetically predisposed individuals. High disease prevalence, absence of a cure, and low diagnosis rates make this disease a public health problem. The diagnosis of CD predominantly relies on recognizing characteristic mucosal alterations of the small intestine, such as villous atrophy, crypt hyperplasia, and intraepithelial lymphocytosis. However, these changes are not entirely specific to CD and overlap with Non-Celiac Duodenitis (NCD) due to various etiologies. We investigated whether Artificial Intelligence (AI) models could assist in distinguishing normal, CD, and NCD (and unaffected individuals) based on the characteristics of small intestinal lamina propria (LP).

METHODS

Our method was developed using a dataset comprising high magnification biopsy images of the duodenal LP compartment of CD patients with different clinical stages of CD, those with NCD, and individuals lacking an intestinal inflammatory disorder (controls). A pre-processing step was used to standardize and enhance the acquired images.

RESULTS

For the normal controls versus CD use case, a Support Vector Machine (SVM) achieved an Accuracy (ACC) of 98.53%. For a second use case, we investigated the ability of the classification algorithm to differentiate between normal controls and NCD. In this use case, the SVM algorithm with linear kernel outperformed all the tested classifiers by achieving 98.55% ACC.

CONCLUSIONS

To the best of our knowledge, this is the first study that documents automated differentiation between normal, NCD, and CD biopsy images. These findings are a stepping stone toward automated biopsy image analysis that can significantly benefit patients and healthcare providers.

Inhibition of Transglutaminase 2 as a Therapeutic Strategy in Celiac Disease-In Vitro Studies in Intestinal Cells and Duodenal Biopsies

Enzymatic modification of gliadin peptides by human transglutaminase 2 (TG2) is a key mechanism in the pathogenesis of celiac disease (CD) and represents a potential therapeutic target. Recently, we have identified the small oxidative molecule PX-12 as an effective inhibitor of TG2 in vitro. In this study, we further investigated the effect of PX-12 and the established active-site directed inhibitor ERW1041 on TG2 activity and epithelial transport of gliadin peptides. We analyzed TG2 activity using immobilized TG2, Caco-2 cell lysates, confluent Caco-2 cell monolayers and duodenal biopsies from CD patients. TG2-mediated cross-linking of pepsin-/trypsin-digested gliadin (PTG) and 5BP (5-biotinamidopentylamine) was quantified by colorimetry, fluorometry and confocal microscopy. Cell viability was tested with a resazurin-based fluorometric assay. Epithelial transport of promofluor-conjugated gliadin peptides P31-43 and P56-88 was analyzed by fluorometry and confocal microscopy. PX-12 reduced TG2-mediated cross-linking of PTG and was significantly more effective than ERW1041 (10 µM, 15 ± 3 vs. 48 ± 8%, p < 0.001). In addition, PX-12 inhibited TG2 in cell lysates obtained from Caco-2 cells more than ERW1041 (10 µM; 12 ± 7% vs. 45 ± 19%, p < 0.05). Both substances inhibited TG2 comparably in the intestinal lamina propria of duodenal biopsies (100 µM, 25 ± 13% vs. 22 ± 11%). However, PX-12 did not inhibit TG2 in confluent Caco-2 cells, whereas ERW1041 showed a dose-dependent effect. Similarly, epithelial transport of P56-88 was inhibited by ERW1041, but not by PX-12. Cell viability was not negatively affected by either substance at concentrations up to 100 µM. PX-12 did not reduce TG2 activity or gliadin peptide transport in confluent Caco-2 cells. This could be caused by rapid inactivation or degradation of the substance in the Caco-2 cell culture. Still, our in vitro data underline the potential of the oxidative inhibition of TG2. The fact that the TG2-specific inhibitor ERW1041 reduced the epithelial uptake of P56-88 in Caco-2 cells further strengthens the therapeutic potential of TG2 inhibitors in CD.

"Geographical distribution of risk genotypes in pediatric patients with celiac disease in Spain"

Celiac disease is strongly associated with HLA DQ, specifically with haplotypes. DRB1*03-DQA1*05:01/DQB1*02:01 (DQ2.5),DRB1*07-DQA1*02:01/DQB1*02:02 (DQ2.2), DRB1*11-DQA1*05:05/DQB1*03:01 (DQ7.5), and DRB1*04-DQA1*03:01/DQB1*03:02 (DQ8). The distribution of these risk haplotypes in patients with celiac disease is different in the geographical areas investigated. A high frequency of DRB1*07- DQA1*02:01/DQB1*02:02 (DQ2.2) and DRB1*11-DQA1*05:05/DQB1*03:01 (DQ7.5), has been described in Southern Europe. We analyzed 2102 confirmed CD cases with information on both DQB1* alelles and their distribution by geographical area in Spain. According to the presence of this haplotype in one or two chromosomes, the genotype is classified in: DQ2 homozygous, DQ2 heterozygous (cis or trans), DQ8 homozygous, DQ8/DQ2.5, DQ 2.2 homozygous and genotype known as "half DQ2". Two different patterns of risks related to CD were identified. In the Basque Country and Navarre, the Mediterranean Area (Aragon, Catalonia, Valencia, Balearic Islands, and Murcia), the South of Spain (Andalucía and Extremadura), and the Canary Islands, higher frequency of DQ2.5 trans, and more than 80% of DQ2.5/DQ2.2 homozygosis were described. The Cantabrian Coast (Cantabria, Asturias, and Galicia) and Central Areas (Castilla-León and Castilla-La Mancha) showed a higher percentage of DQ2.5/DQ2.5 homozygosis and a lower DQ2.5 in trans frequency, as in Northern Europe. Madrid has an intermediate model between the two described above. 17 cases (0.8%) did not carry any CD risk haplotypes.

Akkermansia muciniphila exerts immunomodulatory and anti-inflammatory effects on gliadin-stimulated THP-1 derived macrophages

Macrophages (MQs) pro-inflammatory phenotype is triggered by gliadin peptides. Akkermansia muciniphila (A. muciniphila) showed to enhance the anti-inflammatory phenotype of MQs. This study aimed to investigate the anti-inflammatory effects of A. muciniphila, on gliadin stimulated THP-1 derived macrophages. THP-1 cell line monocytes were differentiated into MQs by phorbol 12-myristate 13-acetate (PMA). MQs were treated with A. muciniphila before and after stimulation with gliadin (pre- and post-treat). CD11b, as a marker of macrophage differentiation, and CD206 and CD80, as M1 and M2 markers, were evaluated by flow cytometry technique. The mRNA expression of TGF-β, IL-6, and IL-10 and protein levels of IL-10 and TNF-α were measured by RT-PCR and ELISA techniques, respectively. Results show an increased percentage of M1 phenotype and release of proinflammatory cytokines (like TNF-α and IL-6) by macrophages upon incubation with gliadin. Pre- and post-treatment of gliadin-stimulated macrophages with A. muciniphila induced M2 phenotype associated with decreased proinflammatory (IL-6, TNF-α) and increased anti-inflammatory (IL-10, TGF-β) cytokines expression relative to the group that was treated with gliadin alone. This study suggests the potential beneficial effect of A. muciniphila on gliadin-stimulated MQs and the importance of future studies focusing on their exact mechanism of action on these cells.

Osteoporosis and Celiac Disease: Updates and Hidden Pitfalls

Celiac disease (CD) is an autoimmune disorder caused by gluten ingestion in genetically predisposed individuals. In addition to the typical gastrointestinal symptoms (e.g., diarrhea, bloating, and chronic abdominal pain), CD may also present with a broad spectrum of manifestations, including low bone mineral density (BMD) and osteoporosis. The etiopathology of bone lesions in CD is multifactorial and other conditions, rather than mineral and vitamin D malabsorption, may affect skeletal health, especially those related to the endocrine system. Here, we describe CD-induced osteoporosis in an attempt to enlighten new and less-known aspects, such as the influence of the intestinal microbiome and sex-related differences on bone health. This review describes the role of CD in the development of skeletal alterations to provide physicians with an updated overview on this debated topic and to improve the management of osteoporosis in CD.

Peroxiredoxins and Hypoxia-Inducible Factor-1α in Duodenal Tissue: Emerging Factors in the Pathophysiology of Pediatric Celiac Disease Patients

Celiac disease (CD) is an autoimmune enteropathy. Peroxiredoxins (PRDXs) are powerful antioxidant enzymes having an important role in significant cellular pathways including cell survival, apoptosis, and inflammation. This study aimed at investigating the expression levels of all PRDX isoforms (1-6) and their possible relationships with a transcription factor, HIF-1α, in the small intestinal tissue samples of pediatric CD patients. The study groups consisted of first-diagnosed CD patients (n = 7) and non-CD patients with functional gastrointestinal tract disorders as the controls (n = 7). The PRDXs and HIF-1α expression levels were determined by using real-time PCR and Western blotting in duodenal biopsy samples. It was observed that the mRNA and protein expression levels of PRDX 5 were significantly higher in the CD patients, whereas the PRDX 1, -2, and -4 expressions were decreased in each case compared to the control group. No significant differences were detected in the PRDX 3 and PRDX 6 expressions. The expression of HIF-1α was also significantly elevated in CD patients. These findings indicate, for the first time, that PRDXs, particularly PRDX 5, may play a significant role in the pathogenesis of CD. Furthermore, our results suggest that HIF-1α may upregulate PRDX-5 transcription in the duodenal tissue of CD.

Prevalence and clinical outcomes of COVID-19 in patients with pre-existing celiac disease: A systematic review and meta-analysis

There is a scarcity of scientific evidence addressing the outcomes of COVID-19 in celiac disease (CD) patients. This systematic review and meta-analysis aimed to evaluate the correlation between pre-existing CD and COVID-19. A rigorous literature search was conducted using multiple databases. All eligible observational studies were included from around the globe. The random effect model calculated the pooled prevalence and associated 95% confidence intervals (CI). Mantel-Haenszel odds ratios were produced to report the overall effect size using random effect models for severity and mortality outcomes. Funnel plots, Egger regression tests, and Begg-Mazumdar's rank correlation test were used to appraise publication bias. Data from 11 articles consisting of 44,378 CD patients were obtained. Overall pooled random-effects estimate of SARS-CoV-2 infection in CD patients was 4.25% (95% CI, I²  = 98%). Our findings also indicated that pre-existing CD was not associated with an increased risk of hospitalisation with COVID-19 illness (OR = 1.04, 95% CI 0.87-1.24, I²  = 0%) and mortality due to illness (OR = 0.92, 95% CI 0.56-1.5, I²  = 45%) compared with patients without pre-existing CD. No significant publication bias was evident in the meta-analysis. The preliminary data from our analysis suggest that SARS-CoV-2 infection in patients with pre-existing CD is not associated with an increased risk of hospitalisation or mortality. Additional studies are required to overcome the restrictions of the limited data available at present.

Adherence to the Mediterranean Diet and Ultra-Processed Foods Consumption in a Group of Italian Patients with Celiac Disease

Evidence on the consumption of ultra-processed foods (UPF) in adults with celiac disease (CD) and its impact on Mediterranean Diet (MD) adherence is still limited. Our aim was to determine UPF consumption and its relationship with MD adherence in a group of adults, according to the presence of CD. This case-control study included 103 adults with CD and 312 without CD. UPF intake was assessed using the NOVA Food Frequency Questionnaire (NFFQ), while MD adherence was assessed using the Medi-Lite score. UPF represented 14.5% of the diet of participants with CD (246 g/day) and came mainly from cereals-based products (29%) and sweets (24.2%). UPF consumption did not differ with the presence of CD, but participants with CD had significantly (p < 0.05) higher consumption of precooked pasta and pre-packaged breads. Participants with CD also reported a significantly lower MD adherence than participants without CD (9.4 vs. 10.4), with higher intake of meat and dairy products, and lower consumption of vegetables and fish. An inverse trend was found between UPF consumption and MD adherence in adults with CD, although not statistically significant. These findings highlight the importance of improving nutrition education for subjects with CD, which should not only focus on gluten exclusion.

Risk of obesity during a gluten-free diet in pediatric and adult patients with celiac disease: a systematic review with meta-analysis

CONTEXT

Obesity is a significant risk factor for many pathological conditions. Whether a gluten-free diet (GFD) is a risk factor for overweight or obesity remains controversial.

OBJECTIVE

The primary aim of this study was to assess the prevalence of body mass index (BMI) categories at disease presentation and the variation in BMI category from underweight/normal to overweight/obese and vice versa during a GFD.

DATA SOURCES

PubMed, Scopus, and Web of Science databases were searched through February 2021 for retrospective, cross-sectional, and prospective studies reporting BMI categories at disease diagnosis and during a GFD.

DATA EXTRACTION

Data were extracted by 2 reviewers independently. Disagreements were resolved by consensus; a third reviewer was consulted, if necessary. Risk of bias was assessed with the Cochrane ROBINS-I tool.

DATA ANALYSIS

Subgroup analysis based on age (pediatric/adult patients), study design (prospective, cross-sectional, retrospective), and duration of GFD was performed.. Forty-five studies were selected (7959 patients with celiac disease and 20 524 healthy controls). The mean BMI of celiac patients at presentation was significantly lower than that of controls (P < 0.001). During a GFD, the mean BMI increased significantly (mean difference = 1.14 kg/m2 [95%CI, 0.68-1.60 kg/m2]; I2 = 82.8%; P < 0.001), but only 9% of patients (95%CI, 7%-12%; I2 = 80.0%) changed from the underweight/normal BMI category to the overweight/obese category, while 20% (95%CI, 11%-29%; I2 = 85.8%) moved into a lower BMI category.

CONCLUSION

Most celiac patients had a normal BMI at presentation, although the mean BMI was significantly lower than that of controls. A GFD does not increase the risk of becoming overweight/obese, especially in children. The quality of several studies was suboptimal, with moderate or high overall risk of bias and heterogeneity.

Gluten-free diet adherence in children with screening-detected celiac disease using a prospective birth cohort study

BACKGROUND

Celiac disease has an increasing incidence worldwide and is treated with lifelong adherence to a gluten-free diet. We aimed to describe gluten-free diet adherence rates in children with screening-identified celiac disease, determine adherence-related factors, and compare adherence to food records in a multinational prospective birth cohort study.

METHODS

Children in The Environmental Determinants of Diabetes in the Young study with celiac disease were included. Subjects had at least annual measurement of adherence (parent-report) and completed 3-day food records. Descriptive statistics, t-tests, Kruskal-Wallis tests and multivariable logistic and linear regression were employed.

RESULTS

Two hundred ninety (73%) and 199 (67%) of subjects were always adherent to a gluten-free diet at 2 and 5 years post celiac disease diagnosis respectively. The percentage of children with variable adherence increased from 1% at 2 years to 15% at 5 years. Children with a first-degree relative with celiac disease were more likely to be adherent to the gluten-free diet. Gluten intake on food records could not differentiate adherent from nonadherent subjects. Adherent children from the United States had more gluten intake based on food records than European children (P < .001 and P = .007 at 2 and 5 years respectively).

CONCLUSION

Approximately three-quarters of children with screening-identified celiac disease remain strictly adherent to a gluten-free diet over time. There are no identifiable features associated with adherence aside from having a first-degree relative with celiac disease. Despite good parent-reported adherence, children from the United States have more gluten intake when assessed by food records. Studies on markers of gluten-free diet adherence, sources of gluten exposure (particularly in the United States), and effects of adherence on mucosal healing are needed.

Is There a Need to Undertake Conventional Gastroscopy and Biopsy When Making the Diagnosis of Coeliac Disease in Adults?

Celiac disease is a common autoimmune condition characterized by small intestinal inflammation and mucosal damage triggered by an inappropriate immune response to ingested gluten. Gastroscopy and duodenal biopsy are currently the gold standard approach to diagnosing celiac disease in adults. However, the emergence of highly accurate serological tests for celiac disease in the last 2 decades led to a change in the pediatric guidelines to diagnose celiac disease without biopsy in selected patients. Adopting this no-biopsy approach to diagnose celiac disease in adults remains controversial, but the evidence supporting it is growing.

Italian guidelines for the management of irritable bowel syndrome: Joint Consensus from the Italian Societies of: Gastroenterology and Endoscopy (SIGE), Neurogastroenterology and Motility (SINGEM), Hospital Gastroenterologists and Endoscopists (AIGO), Digestive Endoscopy (SIED), General Medicine (SIMG), Gastroenterology, Hepatology and Pediatric Nutrition (SIGENP) and Pediatrics (SIP)

The irritable bowel syndrome (IBS) is a chronic disorder of gut-brain interaction. IBS is still associated with areas of uncertainties, especially regarding the optimal diagnostic work-up and the more appropriate management. Experts from 7 Italian Societies conducted a Delphi consensus with literature summary and voting process on 27 statements. Recommendations and quality of evidence were evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus was defined as >80% agreement and reached for all statements. In terms of diagnosis, the consensus supports a positive diagnostic strategy with a symptom-based approach, including the psychological comorbidities assessment and the exclusion of alarm symptoms, together with the digital rectal examination, full blood count, C-reactive protein, serology for coeliac disease, and fecal calprotectin assessment. Colonoscopy should be recommended in patients with alarm features. Regarding treatment, the consensus strongly supports a dietary approach for patients with IBS, the use of soluble fiber, secretagogues, tricyclic antidepressants, psychologically directed therapies and, only in specific IBS subtypes, rifaximin. A conditional recommendation was achieved for probiotics, polyethylene glycol, antispasmodics, selective serotonin reuptake inhibitors and, only in specific IBS subtypes, 5-HT3 antagonists, 5-HT4 agonists, bile acid sequestrants.

Patterns of practice in the diagnosis, dietary counselling and follow-up of patients with celiac disease- A patient-based survey

BACKGROUND

The pattern of practice regarding the diagnosis, dietary counselling and follow-up of patients with celiac disease (CeD) varies between practice to practice.

METHODS

A web-based questionnaire based on review of literature, group discussions and expert group meetings was developed to understand the practice of CeD in India. The questionnaire was administered through social media (WhatsApp) to 18 Indian celiac support groups comprising 2980 patients with CeD.

RESULTS

Overall, 970 (32.5%) patients responded to the questionnaire (median age: 21 years; females 63.9%). While 679 (71.1%) patients were diagnosed based on a combination of serology and biopsy, 214 (22.4%) were diagnosed based on serology alone. After diagnosis, 875 (91%) patients were counselled initially by physician and only 585 (61%) were referred to a dietician for dietary counselling. In a majority of cases, the time spent by doctors and dietitians during first counselling was between 10 and 20 minutes only. After first counselling, 191 (20%) and 355 (37.3%) patients did not re-visit the physician and the dietitian, respectively. Among those who followed up, structured follow-up was conducted in only 515 (53.8%) patients. Overall, 232 (24.3%) patients were self-monitoring their serological parameters, while 495 (51.8%) patients did not receive a formal assessment of dietary adherence during follow-up.

CONCLUSION

The practice of diagnosis, dietary counselling and follow-up of patients with CeD in India is not as per standard guidelines. Most of the patients are not referred to a dietitian. There is a need for reinforcement of guidelines for proper care and management of patients with CeD.

Malignancies in Patients with Celiac Disease: Diagnostic Challenges and Molecular Advances

Celiac disease (CD) is a multiorgan autoimmune disorder of the chronic intestinal disease group characterized by duodenal inflammation in genetically predisposed individuals, precipitated by gluten ingestion. The pathogenesis of celiac disease is now widely studied, overcoming the limits of the purely autoimmune concept and explaining its hereditability. The genomic profiling of this condition has led to the discovery of numerous genes involved in interleukin signaling and immune-related pathways. The spectrum of disease manifestations is not limited to the gastrointestinal tract, and a significant number of studies have considered the possible association between CD and neoplasms. Patients with CD are found to be at increased risk of developing malignancies, with a particular predisposition of certain types of intestinal cancer, lymphomas, and oropharyngeal cancers. This can be partially explained by common cancer hallmarks present in these patients. The study of gut microbiota, microRNAs, and DNA methylation is evolving to find the any possible missing links between CD and cancer incidence in these patients. However, the literature is extremely mixed and, therefore, our understanding of the biological interplay between CD and cancer remains limited, with significant implications in terms of clinical management and screening protocols. In this review article, we seek to provide a comprehensive overview of the genomics, epigenomics, and transcriptomics data on CD and its relation to the most frequent types of neoplasms that may occur in these patients.

Altered Posttranslational Modification of Microtubules Contributes to Disturbed Enterocyte Morphology in Celiac Disease

Celiac disease (CD) represents a frequent autoimmune disease triggered by the ingestion of gliadin in genetically predisposed individuals. The alteration of enterocytes and brush border membrane morphology have been repetitively demonstrated, but the underlying mechanisms remain unclear. Microtubules represent a major element of the cytoskeleton and exert multiple functions depending on their tyrosination status. The aim of our study was to investigate whether posttranslational modification of microtubules was altered in the context of CD and whether this mechanism contributed to morphological changes of CD enterocytes. We examined the expression of tubulin tyrosine ligase (TTL) and vasohibin-2 (VASH2) and the level of detyrosinated and acetylated tubulin in duodenal biopsies and Caco-2 cells by immunoblot and immunofluorescence microcopy. Electron microscopy was performed to investigate the subcellular distribution of detyrosinated tubulin and brush border membrane architecture in CD biopsies and Madin-Darby Canine Kidney type II (MDCK) cells lacking TTL. CD enterocytes and Caco-2 cells stimulated with digested gliadin or IFN-y displayed a flattened cell morphology. This disturbed cellular architecture was accompanied by an increased amount of detyrosinated and acetylated tubulin and corresponding high expression of VASH2 and low expression of TTL. The altered posttranslational modification of tubulin was reversible after the introduction of the gluten-free diet. CD enterocytes and MDCK cells deficient in TTL displayed a reduced cell height along with an increased cell width and a reduced number of apical microvilli. Our results provide a functional explanation for the observed morphological alterations of the enterocytes observed in CD and provide diagnostic potential of the tyrosination status of microtubules as an early marker of villous atrophy and CD inflammation.

The Immunobiology and Pathogenesis of Celiac Disease

Among human leukocyte antigen (HLA)-associated disorders, celiac disease has an immunopathogenesis that is particularly well understood. The condition is characterized by hypersensitivity to cereal gluten proteins, and the disease lesion is localized in the gut. Still, the diagnosis can be made by detection of highly disease-specific autoantibodies to transglutaminase 2 in the blood. We now have mechanistic insights into how the disease-predisposing HLA-DQ molecules, via presentation of posttranslationally modified gluten peptides, are connected to the generation of these autoantibodies. This review presents our current understanding of the immunobiology of this common disorder that is positioned in the border zone between food hypersensitivity and autoimmunity.

Prospects for the treatment of gluten-associated diseases: on our daily bread, celiac disease, gluten proteins and more…

Food safety all over the world is largely dependent on production of grains that are cultivated in 60% of agricultural lands. Wheat is the main food for millions of people and one of the three most commonly cultivated grain cultures worldwide, along with corn and rice. Modern wheat is a product of gene engineering interventions aimed at increased productivity, yields, nutrient quota, and storage time, as well as immunogenic properties. However, the consumption of gluten, a proline and glutamine-rich wheat, rye and barley protein, triggers gluten-dependent disorders, such as celiac disease, wheat allergy, baker's asthma and wheat-dependent exercise-induced anaphylaxis. This group of disorders are curable provided the correct diagnosis has been made and strict lifelong gluten-free diet is implemented. Continuous patient's adherence to the gluten-free diet is associated with a number of medical and paramedical challenges, and the adherence level of the most compliant patients does not exceed 80%. The paper discuss other treatment strategies to improve the nutrition of people with gluten-sensitive disorders, in particular, the reduction grain gluten content, gluten sequestration in the gut before its digestion, prevention of gluten absorption and subsequent immune cell activation, and administration of tissue transglutaminase 2 inhibitors.

Why are western diet and western lifestyle pro-inflammatory risk factors of celiac disease?

The prevalence of celiac disease increased in recent years. In addition to the genetic and immunological factors, it appears that environmental determinants are also involved in the pathophysiology of celiac disease. Gastrointestinal infections impact the development of celiac disease. Current research does not directly confirm the protective effect of natural childbirth and breastfeeding on celiac disease. However, it seems that in genetically predisposed children, the amount of gluten introduced into the diet may have an impact on celiac disease development. Also western lifestyle, including western dietary patterns high in fat, sugar, and gliadin, potentially may increase the risk of celiac disease due to changes in intestinal microbiota, intestinal permeability, or mucosal inflammation. Further research is needed to expand the knowledge of the relationship between environmental factors and the development of celiac disease to define evidence-based preventive interventions against the development of celiac disease. The manuscript summarizes current knowledge on factors predisposing to the development of celiac disease including factors associated with the western lifestyle.

Celiac Disease Genetics, Pathogenesis, and Standard Therapy for Japanese Patients

Celiac disease is an autoimmune disease primarily affecting the small intestine that is caused by the ingestion of gluten in genetically susceptible individuals. The development of celiac disease is based on a complex immune response to gluten proteins. The global average prevalence in the general population is about 1%. In recent years, it has become clear that celiac disease is not less common in Asian countries than in Western countries but often remains undiagnosed. Although the number of patients with celiac disease in Asia is expected to increase with improving disease recognition and advances in diagnostic techniques, there remain few reports of celiac disease in the Far East region of Asia, especially in Japan. In this paper, we outline the epidemiology, diagnosis, and treatment of celiac disease. In addition, we summarize the reported Japanese cases of celiac disease with an overview in Japan.

Prediction of celiac disease associated epitopes and motifs in a protein

Introduction

Celiac disease (CD) is an autoimmune gastrointestinal disorder causes immune-mediated enteropathy against gluten. Gluten immunogenic peptides have the potential to trigger immune responses which leads to damage the small intestine. HLA-DQ2/DQ8 are major alleles that bind to epitope/antigenic region of gluten and induce celiac disease. There is a need to identify CD associated epitopes in protein-based foods and therapeutics.

Methods

In this study, computational tools have been developed to predict CD associated epitopes and motifs. Dataset used for training, testing and evaluation contain experimentally validated CD associated and non-CD associate peptides. We perform positional analysis to identify the most significant position of an amino acid residue in the peptide and checked the frequency of HLA alleles. We also compute amino acid composition to develop machine learning based models. We also developed ensemble method that combines motif-based approach and machine learning based models.

Results and Discussion

Our analysis support existing hypothesis that proline (P) and glutamine (Q) are highly abundant in CD associated peptides. A model based on density of P&Q in peptides has been developed for predicting CD associated peptides which achieve maximum AUROC 0.98 on independent data. We discovered motifs (e.g., QPF, QPQ, PYP) which occurs specifically in CD associated peptides. We also developed machine learning based models using peptide composition and achieved maximum AUROC 0.99. Finally, we developed ensemble method that combines motif-based approach and machine learning based models. The ensemble model-predict CD associated motifs with 100% accuracy on an independent dataset, not used for training. Finally, the best models and motifs has been integrated in a web server and standalone software package "CDpred". We hope this server anticipate the scientific community for the prediction, designing and scanning of CD associated peptides as well as CD associated motifs in a protein/peptide sequence (https://webs.iiitd.edu.in/raghava/cdpred/).

Phenolic Profile and In Vitro Antioxidant Activity of Different Corn and Rice Varieties

Celiac disease (CD) is an autoimmune disease. To date, the only universally recognized treatment for CD is the gluten-free diet (GFD). Despite the GFD, a state of inflammation and oxidative stress could remain at the intestinal level of celiac patients. Several components of the diet, such as phenolic compounds with known antioxidant properties, could play a protective role in the inflammatory state of patients with CD. The objective of this study was the characterization of the phenolic profile and the antioxidant capacity of pigmented cereals (rice and corn) from the Italian market and farms. Different in vitro methods were applied: Folin-Ciocalteu assay, pH differential method, DPPH assay, TEAC assay, and High-Performance Thin Layer Chromatography technique. According to the results, pigmented varieties are possible valuable sources of phenolic compounds and anthocyanins with high antioxidant activity. They could be used as alternative ingredients for the formulation of gluten-free products.

A chromatographic and immunoprofiling approach to optimising workflows for extraction of gluten proteins from flour

Ingestion of gluten proteins from wheat, and related prolamin proteins from barley, rye, and oats, can cause adverse reactions in individuals with coeliac disease and IgE-mediated allergies. As there is currently no cure for these conditions, patients must practice avoidance of gluten-containing foods. In order to support patients in making safe food choices, foods making a "gluten-free" claim must contain no more than 20 mg/Kg of gluten. Mass spectrometry methods have the potential to provide an alternative method for confirmatory analysis of gluten that is complementary to analysis currently undertaken by immunoassay. As part of the development of such methodology the effectiveness of two different extraction procedures was investigated using wholemeal wheat flour before and after defatting with water-saturated butan-1-ol. A single step extraction with 50 % (v/v) propan-2-ol containing 2 M urea and reducing agent (buffer 1) was compared with a two-step extraction using 60 % (v/v) aqueous ethanol (buffer 2) followed by re-extraction of the pellet using buffer 1, using either wheel mixing under ambient conditions (19 °C) or sonication at 60 °C. The procedures were compared based on total protein extraction efficiency and the composition of the extracts determined using a combination of HPLC, SDS-PAGE and immunoblotting with a panel of four gluten-specific monoclonal antibodies. Defatting generally had a detrimental effect on extraction efficiency and sonication at 60 °C only improved extraction efficiency with buffer 2. Although the single-step and two-step procedures were equally effective at extracting protein from the samples, analysis of extracts showed that the two-step method gave a more complete extraction of gluten proteins. Future studies will compare the effectiveness of these procedures when applied in the sample workflows for mass spectrometry based methods for determination of gluten in food.

Pancreatic Cancer in Celiac Disease Patients-A Systematic Review and Meta-Analysis

Background: Celiac disease (CD) is an autoimmune enteropathy affecting approximately 1% of the population and is associated with an increased risk of enteropathy-associated T-cell lymphoma and small bowel adenocarcinoma, whereas the association between CD and other malignancies is unclear. Since pancreatic cancer (PC) remains one of the most lethal neoplasms and its incidence is increasing despite numerous ongoing research on diagnostic biomarkers and novel therapies, we aimed to investigate whether CD has an impact on the risk of PC. Material and Methods: We performed a systematic review of the literature published from January 2000 to March 2022 in two databases: Web of Science and Scopus and a meta-analysis of eligible studies. Results: Our search identified eight publications included in the systematic review. A total of five studies involving 47,941 patients, including 6399 CD patients with malignancies and 1231 PC cases were included in the meta-analysis and 221 cases of PC in CD patients with other cancers were recognized. The pooled OR for PC was 1.46 (95% CI 1.26−1.7) with significant heterogeneity (89.1%; p < 0.05), suggesting that CD patients with malignancies were at higher risk for PC. Conclusions: The association between CD and PC is uncertain. However, the results of the current meta-analysis may indicate an increased risk of PC in the group of patients with CD and other cancers. Further multicenter studies are warranted.

Detection of duodenal villous atrophy on endoscopic images using a deep learning algorithm

BACKGROUND AND AIMS

Celiac disease with its endoscopic manifestation of villous atrophy (VA) is underdiagnosed worldwide. The application of artificial intelligence (AI) for the macroscopic detection of VA at routine EGD may improve diagnostic performance.

METHODS

A dataset of 858 endoscopic images of 182 patients with VA and 846 images from 323 patients with normal duodenal mucosa was collected and used to train a ResNet18 deep learning model to detect VA. An external dataset was used to test the algorithm, in addition to 6 fellows and 4 board-certified gastroenterologists. Fellows could consult the AI algorithm's result during the test. From their consultation distribution, a stratification of test images into "easy" and "difficult" was performed and used for classified performance measurement.

RESULTS

External validation of the AI algorithm yielded values of 90%, 76%, and 84% for sensitivity, specificity, and accuracy, respectively. Fellows scored corresponding values of 63%, 72%, and 67% and experts scored 72%, 69%, and 71%, respectively. AI consultation significantly improved all trainee performance statistics. Although fellows and experts showed significantly lower performance for difficult images, the performance of the AI algorithm was stable.

CONCLUSIONS

In this study, an AI algorithm outperformed endoscopy fellows and experts in the detection of VA on endoscopic still images. AI decision support significantly improved the performance of nonexpert endoscopists. The stable performance on difficult images suggests a further positive add-on effect in challenging cases.

Meta-Analysis and Systematic Review of HLA DQ2/DQ8 in Adults with Celiac Disease

Although people with human leukocyte antigens (HLA) DQ2 and/or DQ8 are more likely to develop celiac disease (CD), the condition cannot be fully explained by this genetic predisposition alone. Multiple, as yet unidentified, factors contribute to the genesis of CD, including genetics, the environment, and the immune system. In order to provide insight into a prospective possibility and an expanded screening technique, we aim to undertake a comprehensive and meta-analytical study of the assessment and distribution of HLA class II (HLA-DQ2/DQ8) in adult CD patients. A systematic review was conducted using an electronic search of databases (PubMed, Google Scholar, Embase, and Direct Science) from January 2004 to February 2022. DQ2/DQ2 homozygotes have the highest risk of developing CD. DQ2/DQ8 typing is an effective test to exclude CD from the differential diagnosis of a patient with CD symptoms. Although other non-HLA genes have been associated with CD, they are rarely considered at diagnosis because they account for only a small proportion of the heritability of CD. This finding, together with the information gathered previously, may be useful in considering widely available and economically feasible screening options for celiac disease in young people.

New Developments in Celiac Disease Treatment

Celiac disease (CD) is a common autoimmune disease affecting around 1% of the population. It consists of an immune-mediated enteropathy, triggered by gluten exposure in susceptible patients. All patients with CD, irrespective of the presence of symptoms, must endure a lifelong gluten-free diet (GFD). This is not an easy task due to a lack of awareness of the gluten content in foods and the extensive incorporation of gluten in processed foods. Furthermore, a GFD imposes a sense of limitation and might be associated with decreased quality of life in CD patients. This results in gluten contamination in the diet of four out of five celiac patients adhering to a GFD. Furthermore, one in three adult patients will report persistent symptoms and two in three will not achieve full histological recovery when on a GFD. In recent years, there has been extensive research conducted in the quest to find the holy grail of pharmacological treatment for CD. This review will present a concise description of the current rationale and main clinical trials related to CD drug therapy.

The effectiveness of gluten-free dietary interventions: A systematic review

Celiac disease is a chronic autoimmune gastroenterological disorder in which the digestion of gluten leads to damage and constant inflammation in the small intestine. Moreover, there are associated physical and mental health problems related to celiac disease, i.e., a lower health-related quality of life and increased depression and anxiety symptoms. The only effective treatment for celiac disease is lifelong adherence to a gluten-free diet. However, researchers suggest that strict adherence to a gluten-free diet ranges from 42 to 80%, depending on the definition and method of assessment that was utilized. This review examines interventions designed for those who need to adhere to life-long dietary measures and their success in terms of increasing gluten-free dietary adherence and improving their health-related quality of life. In April 2022, the Scopus, Web of Science, PubMed and ProQuest databases were searched using the following terms: "coeliac disease" OR "celiac disease" AND "gluten free diet" AND "intervention" AND "health related quality of life" AND "diabetes." Eight studies were suitable for this review. The studies were used to analyze different intervention techniques and their impact on gluten-free dietary adherence, quality of life, and the reasons for dietary nonadherence. The studies revealed statistically significant improvements in the knowledge base regarding celiac disease and the gluten-free diet, dietary adherence and quality-of-life satisfaction immediately after the intervention and at a three-month follow-up. Some studies were also focused on behavioral and cognitive aspects of nonadherence to dietary measures.

Human small-intestinal gluten-degrading bacteria and its potential implication in celiac disease

Celiac disease (CeD) is an immune-mediated chronic disorder triggered by the ingestion of wheat gluten in genetically predisposed individuals. Gluten is a major food ingredient, infamously containing proline and glutamine-rich domains that are highly resistant to digestion by mammalian proteolytic enzymes. Thus, adhering to a gluten-free diet (GFD) is the only known treatment for CeD, albeit with many complications. Therefore, any therapy that eliminates the gluten immunogenic part before it reaches the small intestine is highly desirable. Probiotic therapy containing gluten-degrading bacteria (GDB) and their protease enzymes are possibly new approaches to treating CeD. Our study aimed to identify novel GDB from the duodenal biopsy of the first-degree relative (FDR) subjects (relatives of diseased individuals who are healthy but susceptible to celiac disease) with the potential to reduce gluten immunogenicity. Using the gluten agar plate technique, bacterial strains Brevibacterium casei NAB46 and Staphylococcus arlettae R2AA77 displaying glutenase activity were screened, identified, and characterized. Whole-genome sequencing found gluten-degrading prolyl endopeptidase (PEP) in the B. casei NAB46 genome and glutamyl endopeptidase (GEP) in the S. arlettae R2AA77 genome. Partially purified PEP has a specific activity of 1.15 U/mg, while GEP has a specific activity of 0.84 U/mg, which are, respectively, 6- and 9-fold times higher after concentrating the enzymes. Our results showed that these enzymes could hydrolyse immunotoxic gliadin peptides recognized in western blot using an anti-gliadin antibody. Additionally, a docking model was proposed for representative gliadin peptide PQPQLPYPQPQLP in the active site of the enzymes, where the residues of the N-terminal peptide extensively interact with the catalytic domain of the enzymes. These bacteria and their associated glutenase enzymes efficiently neutralize gliadin immunogenic epitopes, opening possibilities for their application as a dietary supplement in treating CeD patients.

Lane-Hamilton Syndrome in an Adult With Down Syndrome: A Case Report

The Lane-Hamilton syndrome (LHS) is an extremely rare association between celiac disease (CD) and idiopathic pulmonary hemosiderosis (IPH), with only a few cases reported in the literature. The authors report a case of a 32-year-old man with Down syndrome who presented to the emergency department with a history of hemoptysis and chronic diarrhea. The complementary investigation revealed iron deficiency anemia and features suggestive of diffuse alveolar hemorrhage on computed tomography (CT) scan of the chest. After excluding all competing diagnosis, the IPH diagnosis was made. The biopsy of the small intestine confirmed CD and the diagnosis of LHS was established. A gluten-free diet and steroids were given to the patient with a very good clinical response. Since there is an established association between IPH and CD, if the diagnosis of IPH is made, it's recommended to screen for CD even in patients without gastrointestinal symptoms.

Clinical spectrum & changing presentation of celiac disease in Indian children

Background & objectives

Celiac disease (CD) is a genetic immune mediated disorder characterised by gluten intolerance. This single centre study, from north India was aimed to assess the clinical, serological and histological profile of CD in a large cohort of children and the changing trends in its presentation.

Methods

A review of clinical details of CD children diagnosed between 2000 and 2019 and currently on follow up was performed. Information on demography, symptoms, associated conditions, serology, biopsy findings and gluten-free diet were analyzed.

Results

The mean age (±standard deviation) of 891 children included in the study, at onset and at diagnosis was 4.0±2.7 and 6.2±3.1 yr, respectively. Growth faltering, abdominal pain, abdominal distension and diarrhoea were presenting symptoms in 70, 64.2, 61.2 and 58.2 per cent, respectively. A positive family history of CD was present in 14 per cent and autoimmune conditions in 12.3 per cent of children. Thyroid disorders were seen in 8.5 per cent of children and Type 1 diabetes mellitus (T1DM) in 5.7 per cent. The duration of breastfeeding had a weak positive correlation with age at onset and diagnosis of CD (P<0.001). Non-classical CD was significantly more common in children aged >10 yr and in those presenting after 2010 (P<0.01). T1DM and hypothyroidism occurred more frequently in non-compliant children.

Interpretation & conclusions

This was the largest single centre study, pertaining to the presentation and follow up of CD in children. Infants and young children were more likely to present with classical symptoms of diarrhoea, abdominal distension and growth failure while older children presented with non-classical CD. There was a trend towards non-classical forms of CD in recent years.

The emerging roles of bacterial proteases in intestinal diseases

Proteases are an evolutionarily conserved family of enzymes that degrade peptide bonds and have been implicated in several common gastrointestinal (GI) diseases. Although luminal proteolytic activity is important for maintenance of homeostasis and health, the current review describes recent advances in our understanding of how overactivity of luminal proteases contributes to the pathophysiology of celiac disease, irritable bowel syndrome, inflammatory bowel disease and GI infections. Luminal proteases, many of which are produced by the microbiota, can modulate the immunogenicity of dietary antigens, reduce mucosal barrier function and activate pro-inflammatory and pro-nociceptive host signaling. Increased proteolytic activity has been ascribed to both increases in protease production and decreases in inhibitors of luminal proteases. With the identification of strains of bacteria that are important sources of proteases and their inhibitors, the stage is set to develop drug or microbial therapies to restore protease balance and alleviate disease.

Cohort profile: Celiac disease genomic, environmental, microbiome and metabolome study; a prospective longitudinal birth cohort study of children at-risk for celiac disease

The Celiac Disease Genomic, Environmental, Microbiome and Metabolomic (CDGEMM) study is an international prospective birth cohort in children at-risk of developing celiac disease (CD). The CDGEMM study has been designed to take a multi-omic approach to predicting CD onset in at-risk individuals. Participants are required to have a first-degree family member with biopsy diagnosed CD and must be enrolled prior to the introduction of solid food. Participation involves providing blood and stool samples longitudinally over a period of five years as well as answering questionnaires related to the participant, their family, and environment. Recruitment and data collection have been ongoing since 2014. As of 2022 we have a total of 554 participants and the average age of the cohort is 56.4 months. A total of 54 participants have developed positive antibodies for CD and 31 have confirmed CD. Approximately 80% of the 54 participants with CD have developed it by 3 years of age. To date we have identified several microbial strains, pathways, and metabolites occurring in increased abundance and detected before CD onset, which have previously been linked to autoimmune and inflammatory conditions while others occurred in decreased abundance before CD onset and are known to have anti-inflammatory effects. Our ongoing analysis includes expanding our metagenomic and metabolomic analyses, evaluating environmental risk factors linked to CD onset, and mechanistic studies investigating how alterations in the microbiome and metabolites may protect against or contribute to CD development.

Point-of-Care Screening for Coeliac Disease in Schoolchildren Reveals Higher Disease Prevalence in Croatia

Coeliac disease (CD) is an immune-mediated inflammatory disease triggered by dietary gluten and related proteins in genetically predisposed individuals. Point-of-care (POC) methods are non-invasive and easily performed tests, which could help to reduce the diagnostic delay of CD. The aim of our study was to determine the prevalence of CD using rapid POC test in first-grade schoolchildren in Zagreb, Croatia. A rapid qualitative immunoassay POC test designed for detection of immunoglobulin (Ig) A and IgG deamidated gliadin antibodies (DGP), as well as total IgA (to identify IgA deficient patients) in whole blood, was used to test healthy children on gluten containing diet. Out of 1404 tested children (51% female), 85 (6.05%) had a positive rapid POC test result and were referred to paediatric gastroenterologist. Finally, 7 children were diagnosed with CD (0.5%). There was no significant difference in children with CD and children with positive POC but negative serology in sex, BMI, or symptoms. However, children diagnosed with CD complained of abdominal pain significantly more often. The prevalence of CD in first-grade schoolchildren was 1:200 (0.5%), higher than in previous studies performed in Croatia. The results imply the possible benefit of IgA and IgG DGP-based POC tests in population screening.

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.

Prevalence of celiac disease in patients with liver diseases: a systematic review and meta-analyses

OBJECTIVES

A subset of patients with celiac disease (CeD) have liver involvement in the form of hypertransaminasemia, liver cirrhosis and autoimmune hepatitis. We conducted a systematic review with meta-analyses to determine pooled prevalence of CeD in patients with cryptogenic cirrhosis, all-cause cirrhosis, cryptogenic hypertransaminasemia, and all-cause hypertransaminasemia.

METHODS

We searched PubMed and EMBASE up to January 2022. Cross-sectional, case-control and prospective cohort studies performing serological tests and/or intestinal biopsy for CeD on patients with cryptogenic cirrhosis, all-cause cirrhosis, cryptogenic hypertransaminasemia and all-cause hypertransaminasemia were included, to calculate pooled estimates of seroprevalence and prevalence of biopsy-confirmed CeD in these four groups.

RESULTS

Of 6,871 articles screened, 20 articles were included finally in three meta-analyses for cryptogenic cirrhosis, all-cause cirrhosis and cryptogenic hypertransaminasemia. For the all-cause hypertransaminasemia group, a qualitative review of four studies was done instead of a meta-analysis, due to significant differences in studies. The pooled prevalence (95%CI) of biopsy-confirmed CeD, in cryptogenic cirrhosis was 4.6%(2.2-7.5%) while pooled prevalence of biopsy-confirmed CeD in all-cause cirrhosis was 0.8%(0-3.4%). Pooled prevalence of biopsy-confirmed CeD in cryptogenic hypertransaminasemia was 5.7%(3.2-8.8%).

CONCLUSIONS

Nearly one in 20 patients each with cryptogenic cirrhosis and cryptogenic hypertransaminasemia have CeD, hence they should both be considered high-risk groups for CeD. While prevalence of CeD in all-cause cirrhosis is similar to that in general population, it may be worth screening them for CeD as liver pathology has potential for reversal in them.

Evaluation of the Potential Anti-Inflammatory Activity of Black Rice in the Framework of Celiac Disease

Inflammation and oxidative stress are two mechanisms involved in the pathogenesis of celiac disease (CD). Since the direct effect of gliadin on the intestinal epithelia is less studied, the aims of this study were the development of a specific cellular model based on the use of gliadin as a pro-inflammatory stimulus and the evaluation of the potential antioxidant and anti-inflammatory properties of extracts from different black rice in the framework of CD. The rice extracts were in vitro digested, characterized in terms of phenolic compounds and antioxidant capacity, and tested on Caco-2 cells to investigate their inhibitory effect on Reactive Oxygen Species, the NF-κB transcription and the CXC chemokines (sICAM-1, IL-8, and CXCL-10). In addition, the role of the extracts in modulating the activation of epithelial cells in CD was confirmed by applying the K562(S) agglutination test. The black rice extracts showed inhibitory effects on the production of the oxidative and the inflammatory mediators considered, with particular reference to lymphocyte-attracting CXCL-10 both before and after digestion. The presence of anthocyanins and their digestion metabolites may account for the observed anti-inflammatory activity after in vitro digestion. This work provided preliminary data supporting the use of black rice as a healthy food or ingredient of food supplements for celiacs.

Antioxidant Properties of Gluten-Free Pasta Enriched with Vegetable By-Products

The only therapy for coeliac disease patients is to completely avoid foods containing gluten, a protein complex common in several small-grain cereals. However, many alternative gluten-free foods available on the market present nutritional deficiencies. Therefore, the aim of this research was to evaluate the composition and the antioxidant properties of gluten-free pasta enriched with 10% or 15% of tomato waste or linseed meal, two food industry by-products. The traits analysed were protein, lipid, ash and fibre content, heat damage, tocols, carotenoids and phenolics composition (by HPLC), antioxidant capacity, and pasta fracturability. The enriched pastas contained more fibre and lipids than the control, while the protein and ash values were similar. The addition of tomato and linseed waste improved tocols concentration but had no effect on carotenoids content. The free soluble polyphenols increase was similar for both by-products and proportional to the enrichment percentage, while the bound insoluble polyphenols were higher in linseed-enriched pastas. The samples with linseed meal showed the greatest antioxidant capacity and, at 10% addition, the highest fracturability value. In conclusion, the addition of tomato and linseed by-products significantly increases the presence of bioactive compounds (particularly polyphenols), improving the nutritional value of gluten-free pasta.

Prevalence of functional gastrointestinal disorders in children with celiac disease on different types of gluten-free diets

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are common during the pediatric age. FGIDs are not related to biochemical or structural abnormalities. However, since they have a high prevalence, several studies have evaluated an overlap between FGIDs and organic diseases. Individuals with celiac disease (CD) have been shown to be at an increased risk for functional abdominal pain, even if they adhere well to a gluten-free diet (GFD). Little information is available for the pediatric age group. The aims of our study were to evaluate the prevalence of FGIDS in CD children 1 year after diagnosis and to compare the prevalence of FGIDs in CD children on a GFD with processed foods compared with those on a GFD with natural products.

AIM

To assess the prevalence of FGIDs in children with CD after 1 year of follow-up and to compare the prevalence of FGIDs in children with CD on a GFD with processed foods and in children on a GFD with natural products.

METHODS

We recruited pediatric patients aged 1-18 years with a new CD diagnosis. Participants were randomized to two groups: Group A on a GFD with processed foods (diet 1); and group B on a GFD with natural products (diet 2). Clinical monitoring, diet assessment and the questionnaire on pediatric gastrointestinal symptoms-Rome IV version were performed at diagnosis (T0) and after 12 mo of follow-up (T1). Dietary intake was assessed using a 3-d food diary record. Data from the diaries were evaluated using WinFood nutrient analysis software. We assessed the prevalence of FGIDs at T1 and the correlation with the type of GFD.

RESULTS

We registered 104 CD children, with 55 patients in group A (53.0%) and 49 patients in group B (47.0%). Initially, 30 of the 55 (54.5%) CD children were symptomatic in group A, while 25 of 49 (51.0%) were symptomatic in group B. At T1, in spite of a low or negative serology for CD, FGIDs prevalence was 10/55 (18.0%) in group A and 8/49 (16.3%) in group B, with no statistically significant difference between the two groups (P = 0.780). At T1 the macro- and micronutrient intake was similar across the two groups with no significant differences in nutrient analysis. However, in both groups at T1 we found that a lower prevalence of FGIDs (P = 0.055) was associated with an inferior caloric (odds ratio = 0.99, 95% confidence interval: 0.99-1.00) and fat (odds ratio = 0.33, 95% confidence interval: 0.65-0.95) intake.

CONCLUSION

Our results showed that CD children on a GFD have gastrointestinal symptoms with an elevated prevalence of FGIDs. Our study suggests that developing FGIDs may be linked to caloric intake and percentage of food fat, but it does not change between a GFD with processed foods or a GFD with natural products. However, long-term monitoring is required to evaluate a correlation between FGIDs and various types of GFDs.

Effect of a gluten-free diet on bone mineral density in children and adolescents with celiac disease: Systematic review and meta-analysis

Studies suggest an association between a gluten-free diet (GFD) and bone health in celiac disease (CD). However, the evidence on this relationship in children and adolescents is limited. Thus, this systematic review and meta-analysis aimed to analyze the effect of GFD on the bone health and anthropometric profile of children and adolescents with CD. Five databases were searched up to January, 2022 to identify relevant studies. The studies' methodological quality was evaluated using two scales. The Hedge's g standardized mean differences (SMD) with 95% confidence intervals were estimated using a random-effects model. The GRADE approach was used to assess the quality of evidence. Twenty-eight studies were included in the final review. GFD increased bone mineral content (BMC) (SMD = 0.39; 95%CI = 0.16, 0.62) and bone mineral density (BMD) (SMD = 0.29; 95%CI = 0.10, 0.47) in CD individuals. Difference in mean BMC and BMD between children and adolescents with CD versus healthy individuals was -0.49 (95%CI = -0.76, -0.22) and -0.47 (SMD = -95%CI = -0.72, -0.22), respectively. There was no difference in BMI and body fat among celiac children and adolescents versus healthy controls. In conclusion, GFD was associated with higher BMC and BMD in children and adolescents with CD.

Role of Vitamin D in Celiac Disease and Inflammatory Bowel Diseases

Vitamin D (VD) is a pro-hormone that has long been known as a key regulator of calcium homeostasis and bone health in both children and adults. In recent years, studies have shown that VD may exert many extra-skeletal functions, mainly through a relevant modulation of the innate and adaptive immune system. This has suggested that VD could play a fundamental role in conditioning development, clinical course, and treatment of several autoimmune disorders, including celiac disease (CD) and inflammatory bowel diseases (IBDs). The main aim of this review is to evaluate the relationships between VD, CD, and IBDs. Literature analysis showed a potential impact of VD on CD and IBDs can be reasonably assumed based on the well-documented in vitro and in vivo VD activities on the gastrointestinal tract and the immune system. The evidence that VD can preserve intestinal mucosa from chemical and immunological damage and that VD modulation of the immune system functions can contrast the mechanisms that lead to the intestinal modifications characteristic of gastrointestinal autoimmune diseases has suggested that VD could play a role in controlling both the development and the course of CD and IBDs. Administration of VD in already diagnosed CD and IBD cases has not always significantly modified disease course. However, despite these relevant problems, most of the experts recommend monitoring of VD levels in patients with CD and IBDs and administration of supplements in patients with hypovitaminosis.