Opportunities for Improving Biopsy and Non-Biopsy-Based Diagnosis of Celiac Disease.

The accumulating data regarding a non-biopsy diagnosis of celiac disease has led to its adoption in certain scenarios, although debate on whether and when to use non-biopsy criteria in clinical practice is ongoing. Despite the growing popularity and evidence basis for a biopsy-free approach to diagnosis in the context of highly elevated serologies, there will continue to be a role for a biopsy in some groups. This review summarizes the current evidence supporting a non-biopsy approach and arguments supporting continued reliance on biopsy, and focuses on opportunities to improve both approaches.

AGA Clinical Practice Guideline on Fecal Microbiota-Based Therapies for Select Gastrointestinal Diseases.

BACKGROUND & AIMS: Fecal microbiota-based therapies include conventional fecal microbiota transplant and US Food and Drug Administration-approved therapies, fecal microbiota live-jslm and fecal microbiota spores live-brpk. The American Gastroenterological Association (AGA) developed this guideline to provide recommendations on the use of fecal microbiota-based therapies in adults with recurrent Clostridioides difficile infection; severe to fulminant C difficile infection; inflammatory bowel diseases, including pouchitis; and irritable bowel syndrome. METHODS: The guideline was developed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) framework to prioritize clinical questions, identify patient-centered outcomes, and conduct an evidence synthesis. The guideline panel used the Evidence-to-Decision framework to develop recommendations for the use of fecal microbiota-based therapies in the specified gastrointestinal conditions and provided implementation considerations for clinical practice. RESULTS: The guideline panel made 7 recommendations. In immunocompetent adults with recurrent C difficile infection, the AGA suggests select use of fecal microbiota-based therapies on completion of standard of care antibiotics to prevent recurrence. In mildly or moderately immunocompromised adults with recurrent C difficile infection, the AGA suggests select use of conventional fecal microbiota transplant. In severely immunocompromised adults, the AGA suggests against the use of any fecal microbiota-based therapies to prevent recurrent C difficile. In adults hospitalized with severe or fulminant C difficile not responding to standard of care antibiotics, the AGA suggests select use of conventional fecal microbiota transplant. The AGA suggests against the use of conventional fecal microbiota transplant as treatment for inflammatory bowel diseases or irritable bowel syndrome, except in the context of clinical trials. CONCLUSIONS: Fecal microbiota-based therapies are effective therapy to prevent recurrent C difficile in select patients. Conventional fecal microbiota transplant is an adjuvant treatment for select adults hospitalized with severe or fulminant C difficile infection not responding to standard of care antibiotics. Fecal microbiota transplant cannot yet be recommended in other gastrointestinal conditions.

New entity of adult ultra-short coeliac disease: the first international cohort and case-control study.

BACKGROUND: Ultra-short coeliac disease (USCD) is defined as villous atrophy only present in the duodenal bulb (D1) with concurrent positive coeliac serology. We present the first, multicentre, international study of patients with USCD. METHODS: Patients with USCD were identified from 10 tertiary hospitals (6 from Europe, 2 from Asia, 1 from North America and 1 from Australasia) and compared with age-matched and sex-matched patients with conventional coeliac disease. FINDINGS: Patients with USCD (n=137, median age 27 years, IQR 21-43 years; 73% female) were younger than those with conventional coeliac disease (27 vs 38 years, respectively, p<0.001). Immunoglobulin A-tissue transglutaminase (IgA-tTG) titres at index gastroscopy were lower in patients with USCD versus conventional coeliac disease (1.8×upper limit of normal (ULN) (IQR 1.1-5.9) vs 12.6×ULN (IQR 3.3-18.3), p<0.001).Patients with USCD had the same number of symptoms overall (median 3 (IQR 2-4) vs 3 (IQR 1-4), p=0.875). Patients with USCD experienced less iron deficiency (41.8% vs 22.4%, p=0.006).Both USCD and conventional coeliac disease had the same intraepithelial lymphocytes immunophenotype staining pattern; positive for CD3 and CD8, but not CD4.At follow-up having commenced a gluten-free diet (GFD) (median of 1181 days IQR: 440-2160 days) both USCD and the age-matched and sex-matched controls experienced a similar reduction in IgA-tTG titres (0.5 ULN (IQR 0.2-1.4) vs 0.7 ULN (IQR 0.2-2.6), p=0.312). 95.7% of patients with USCD reported a clinical improvement in their symptoms. INTERPRETATION: Patients with USCD are younger, have a similar symptomatic burden and benefit from a GFD. This study endorses the recommendation of D1 sampling as part of the endoscopic coeliac disease diagnostic workup.

Coeliac disease and type 2 diabetes risk: a nationwide matched cohort and Mendelian randomisation study.

AIMS/HYPOTHESIS: While the association between coeliac disease and type 1 diabetes is well documented, the association of coeliac disease with type 2 diabetes risk remains undetermined. We conducted a nationwide cohort and Mendelian randomisation analysis to investigate this link. METHODS: This nationwide matched cohort used data from the Swedish ESPRESSO cohort including 46,150 individuals with coeliac disease and 219,763 matched individuals in the comparator group selected from the general population, followed up from 1969 to 2021. Data from 9053 individuals with coeliac disease who underwent a second biopsy were used to examine the association between persistent villous atrophy and type 2 diabetes. Multivariable Cox regression was employed to estimate the associations. In Mendelian randomisation analysis, 37 independent genetic variants associated with clinically diagnosed coeliac disease at p<5×10-8 were used to proxy genetic liability to coeliac disease. Summary-level data for type 2 diabetes were obtained from the DIAGRAM consortium (80,154 cases) and the FinnGen study (42,593 cases). RESULTS: Over a median 15.7 years' follow-up, there were 6132 (13.3%) and 30,138 (13.7%) incident cases of type 2 diabetes in people with coeliac disease and comparator individuals, respectively. Those with coeliac disease were not at increased risk of incident type 2 diabetes with an HR of 1.00 (95% CI 0.97, 1.03) compared with comparator individuals. Persistent villous atrophy was not associated with an increased risk of type 2 diabetes compared with mucosal healing among participants with coeliac disease (HR 1.02, 95% CI 0.90, 1.16). Genetic liability to coeliac disease was not associated with type 2 diabetes in DIAGRAM (OR 1.01, 95% CI 0.99, 1.03) or in FinnGen (OR 1.01, 95% CI 0.99-1.04). CONCLUSIONS/INTERPRETATION: Coeliac disease was not associated with type 2 diabetes risk.

Association Between Celiac Disease and Irritable Bowel Syndrome: A Nationwide Cohort Study.

BACKGROUND & AIMS: The aim of this study was to determine the risk of irritable bowel syndrome (IBS) diagnosis in patients with celiac disease (CD) compared with general population comparators. METHODS: Using Swedish histopathology and register-based data, we identified 27,262 patients with CD diagnosed in 2002-2017 and 132,922 age- and sex-matched general population comparators. Diagnoses of IBS were obtained from nationwide inpatient and non-primary outpatient records. Cox regression estimated hazard ratios (aHRs) for IBS adjusted for education level and Charlson Comorbidity Index. To reduce potential surveillance bias our analyses considered incident IBS diagnosis ≥1 year after CD diagnosis. Using conditional logistic regression, secondary analyses were calculated to estimate odds ratios (ORs) for IBS diagnosis ≥1 year before CD diagnosis. RESULTS: During an average of 11.1 years of follow-up, 732 celiac patients (2.7%) were diagnosed with IBS vs 1131 matched general population comparators (0.9%). Overall (≥1-year of follow-up), the aHR for IBS was 3.11 (95% confidence interval [CI], 2.83-3.42), with aHR of 2.00 (95% CI, 1.63-2.45) after ≥10 years of follow-up. Compared with siblings (n = 32,010), celiac patients (n = 19,211) had ≥2-fold risk of later IBS (aHR, 2.42; 95% CI, 2.08-2.82). Compared with celiac patients with mucosal healing, those with persistent villus atrophy on follow-up biopsy were less likely to be diagnosed with IBS (aHR, 0.66; 95% CI, 0.46-0.95). CD was also associated with having an earlier IBS diagnosis (OR, 3.62; 95% CI, 3.03-4.34). CONCLUSIONS: In patients with CD, the risk of IBS is increased long before and after diagnosis. Clinicians should be aware of these long-term associations and their implications on patient management.

Older age of celiac disease diagnosis and risk of autoimmune disease: A nationwide matched case-control study.

OBJECTIVES: Celiac disease (CeD) has been linked to an increased risk of other autoimmune diseases, yet the impact of delayed CeD diagnosis on risk of developing additional autoimmune diseases remains uncertain. We investigated this through a nationwide matched case-control study. METHODS: Using the ESPRESSO cohort with histophatology data from Sweden's 28 pathology departments, we assessed 46,575 biopsy-confirmed CeD cases from 1964 to 2017. We extracted 225,295 matched controls without histopathology information from the Swedish Total Population Register. Autoimmune disease was defined through diagnostic codes in the National Patient Register. Through conditional logistic regression we estimated odds ratio (OR) of autoimmune disease up until CeD diagnosis/matching date comparing CeD cases to controls across different age strata. RESULTS: A total of 3059 (6.6 %) CeD patients and 4076 (1.8 %) controls had earlier autoimmune disease. The overall OR for autoimmune disease in CeD was 3.50 (95%CI 3.32-3.70). The risk of autoimmune disease did not escalate with increasing age at CeD diagnosis. Compared with controls, the OR of autoimmune disease in CeD patients was 7.70 (95%CI 4.71-12.57) in those diagnosed with CeD in 0-4 years, 19.02 (95%CI 13.80-26.23) in 5-9 years, 6.18 (95%CI 5.14-7.44) in 10-14 years, 4.80 (95%CI 3.97-5.79) in 15-19 years, 4.24 (95%CI 3.55-5.07) in 20-29 years, 4.65 (95%CI 3.93-5.51) in 30-39 years, 3.67 (95%CI 3.30-4.09) in 40-59 years, and 1.67 (95%CI 1.50-1.85) in ≥60 years. CONCLUSIONS: This study revealed an increased risk of autoimmune disease among CeD patients compared with controls. However, older age at CeD diagnosis did not seem to escalate the risk of autoimmune diseases.

Prevalence and Predictors of Follow-up Endoscopic Biopsy in Patients With Celiac Disease in the United States.

OBJECTIVE: To characterize the frequency and predictors of follow-up endoscopic biopsy in patients with celiac disease. BACKGROUND: The utility of routine follow-up biopsy in patients after a diagnosis of celiac disease is uncertain, especially in patients whose symptoms resolve on the gluten-free diet. PATIENTS AND METHODS: Using the Merative MarketScan U.S. commercial insurance and Medicare databases, we identified 30,737 patients with biopsy-diagnosed celiac disease. We followed them until they had a second duodenal biopsy (our primary outcome) or insurance coverage ended. RESULTS: Among the patients with celiac disease we identified, 5976 (19.4%) underwent a follow-up biopsy. The median time between initial and follow-up biopsies was 16.8 months. Compared with younger patients, those aged 20 years or older had an increased likelihood of undergoing a follow-up biopsy (cumulative incidence rate at 5 y for patients age ≥20 y was 36.0%, 95% CI: 35.0%-37.1% vs 21.9%, 95% CI: 20.5%-23.4% in patients age ≤19 y). Follow-up biopsies occurred less frequently in more recent calendar years. Follow-up biopsy was more common among patients with an Elixhauser Comorbidity Index of 1 (hazard ratio: 1.09; 95% CI: 1.01-1.17) or ≥2 (hazard ratio: 1.28; 95% CI: 1.20-1.37) compared with patients with an index of zero. Among patients who had a follow-up biopsy, 57% had a celiac disease-related symptom recorded in the 30 days before the procedure. CONCLUSIONS: Follow-up duodenal biopsy is performed in a substantial minority of U.S. patients with celiac disease. Adult age and increased comorbidity burden were associated with a greater likelihood of follow-up biopsy. Just under half of follow-up biopsies are performed for routine surveillance, in the absence of persistent symptoms.

Predominantly antibody deficiency and the association with celiac disease in Sweden: A nationwide case-control study.

BACKGROUND: Predominantly antibody deficiency (PAD) is associated with noninfectious inflammatory gastrointestinal disease. Population estimates of celiac disease (CeD) risk in those with PAD are limited. OBJECTIVE: To estimate population risk of PAD in individuals with CeD. METHODS: We conducted a nationwide case-control study in Swedish individuals who received a diagnosis of CeD between 1997 and 2017 (n = 34,980), matched to population comparators by age, sex, calendar year, and county. The CeD was confirmed through the Epidemiology Strengthened by histopathology Reports in Sweden study, which provided information on biopsy specimens from each of Sweden's pathology departments. PAD was identified using International Classification of Diseases, 10th Revision coding and categorized according to the International Union of Immunologic Societies. Logistic regression was used to calculate adjusted odds ratios (aORs) and 95% CIs. RESULTS: PAD was more prevalent in CeD than in population controls (n = 105 [0.3%] vs n = 57 [0.033%], respectively). This translated to an aOR of 8.23 (95% CI 5.95-11.48). The association was strongest with common variable immunodeficiency (aOR 17.25; 95% CI 6.86-52.40), and slightly lower in other PAD (aOR 8.39; 95% CI 5.79-12.32). The risk of CeD remained increased at least 5 years after diagnosis of PAD (aOR 4.79; 95% CI 2.89-7.97, P-heterogeneity ≤ 0.001). CONCLUSION: PAD was associated with an increased risk of CeD. A particularly strong association was seen in those with CVID, although this should be interpreted cautiously given the limited understanding of the mechanisms of histopathologic changes in these patients.

Predictors of Subsequent Celiac Disease Seropositivity in Patients Diagnosed with Duodenal Villus Atrophy on Upper Endoscopy.

BACKGROUND: The diagnosis of celiac disease (CD) is based on positive IgA autoantibodies to tissue transglutaminase (TTG IgA) and confirmatory histopathology demonstrating duodenal villus atrophy (VA). Diagnostic challenges can occur when VA is found on duodenal biopsies in patients without prior CD serologies. AIMS: To characterize the predictors of CD seropositivity in patients with VA on biopsy without prior CD serologies. METHODS: We performed a retrospective cohort study of patients found to have duodenal VA on histopathology from 2010 to 2020 who did not have prior CD serologies measured and who had them checked after their biopsy. Patients with known or suspected CD prior to their duodenal biopsy were excluded. RESULTS: Of 162 patients with VA and no prior CD serologies, 50 (31%) subsequently had an elevated TTG IgA consistent with CD. Patients with an elevated TTG IgA were more likely to be non-Hispanic (76% vs. 42%; p < 0.001), white (74% vs. 62%; p = 0.025), and younger (ages 18-39, 26% vs. 12%; p = 0.002) compared to those with a negative TTG IgA. By contrast, these patients were less likely to present in middle adulthood (ages 40-59, 6% vs. 29%; p =  0.002). The most common identified etiologies of seronegative VA were Crohn's disease (13%), seronegative CD (8.9%), H. pylori infection (6.3%), tropical sprue (5.4%), and olmesartan-related enteropathy (3.6%). CONCLUSION: Age and ethnicity may be helpful when stratifying the likelihood of CD in the absence of supporting serologies. A majority of patients (69%) diagnosed with VA without prior CD serologies have negative serologies, consistent with seronegative CD or the spectrum of non-celiac enteropathies for which further evaluation is needed.

Yield of Gluten Challenge in Patients on Self-Prescribed Gluten-Free Diets.

BACKGROUND: Patients on a gluten-free diet (GFD) whose celiac disease (CD) status is unknown may undergo gluten challenge (GC) to clarify their diagnosis. Though this is an established diagnostic practice, the proportion of patients undergoing GC who are diagnosed with CD is unknown. AIMS: We aimed to analyze which factors were predictive of having CD in a cohort of patients who underwent GC followed by upper endoscopy with duodenal biopsy. METHODS: We identified adult patients at a CD referral center who had been on a GFD and then underwent GC to determine a diagnosis of CD during the years spanning 2006 to 2020. We compared those patients found to have CD (defined as villus atrophy/Marsh 3) on duodenal biopsy with those who did not, using the chi square and Fischer exact tests. RESULTS: We identified 206 patients who underwent GC. Of these 206, 30 (14%) were diagnosed with CD based on post-GC duodenal biopsy. 176 of the 206 (85%) patients reported various gastrointestinal symptoms, including bloating (39%), though these were more common in those without CD (any GI symptoms: 89% vs 67%, p 0.004; bloating: 43% vs 20%, p 0.019). Serology values, when normalized, including pre- and post-challenge TTG IgA (37% vs 1.7%, p 0.001; 23% versus 2.3%, p 0.001), DGP IgG and IgA (57% vs 2.8%, p 0.001; 37% vs 6.2%, p 0.001) were higher in the group of patients with CD. CONCLUSION: Among patients undergoing GC for diagnostic purposes, only 14% had evidence of villus atrophy corresponding with CD on duodenal biopsy. The presence of any elevated pre-challenge serology was associated with CD. Bloating in combination with low serologies may help risk stratify patients as being less likely to have CD upon GC.

Phenome-wide Mendelian randomization analysis reveals multiple health comorbidities of coeliac disease.

BACKGROUND: Coeliac disease (CeD) has been associated with a broad range of diseases in observational data; however, whether these associations are causal remains undetermined. We conducted a phenome-wide Mendelian randomization analysis (MR-PheWAS) to investigate the comorbidities of CeD. METHODS: Single nucleotide polymorphisms (SNPs) associated with CeD at the genome-wide significance threshold and without linkage disequilibrium (R2 <0.001) were selected from a genome-wide association study including 12,041 CeD cases as the instrumental variables. We first constructed a polygenic risk score for CeD and estimated its associations with 1060 unique clinical outcomes in the UK Biobank study (N = 385,917). We then used two-sample MR analysis to replicate the identified associations using data from the FinnGen study (N = 377,277). We performed a secondary analysis using a genetic instrument without extended MHC gene SNPs. FINDINGS: Genetic liability to CeD was associated with 68 clinical outcomes in the UK Biobank, and 38 of the associations were replicated in the FinnGen study. Genetic liability to CeD was associated with a higher risk of several autoimmune diseases (type 1 diabetes and its complications, Graves' disease, Sjögren syndrome, chronic hepatitis, systemic and cutaneous lupus erythematosus, and sarcoidosis), non-Hodgkin's lymphoma, and osteoporosis and a lower risk of prostate diseases. The associations for type 1 diabetes and non-Hodgkin's lymphoma attenuated when excluding SNPs in the MHC region, indicating shared genetic aetiology. INTERPRETATION: This study uncovers multiple clinical outcomes associated with genetic liability to CeD, which suggests the necessity of comorbidity monitoring among this population. FUNDING: This project was funded by Karolinska Institutet and the Swedish Research Council.

Implementing Public Health Modules as an Approach to Improve Knowledge and Attitudes of Medical Students: A Student-Led, Multiyear Study.

PURPOSE: Public health is a necessary focus of modern medical education. However, while numerous studies demonstrate benefits of public health education during medical school among self-selected students (i.e., those interested in public health), there are few educational models shown to be effective across the general medical student population. This study examined the effect of a multiyear, case-based, longitudinal online public health curriculum required for all medical students at an urban, research-focused U.S. medical school. METHOD: The authors created 11 short public health modules to supplement a year-long, organ-based preclerkship course at Columbia University Vagelos College of Physicians and Surgeons. Beginning in 2020, all students were required to complete these modules, with repeated surveys to assess changes in attitudes and knowledge of public health over time. The authors compared responses for these domains before and after each module, across multiple time points throughout the year, and cross-sectionally to a 2019 cohort of students who were not provided the modules. RESULTS: Across 3 cohorts, 405 of 420 (96.4%) students provided responses and were included in subsequent analyses. After completing the modules, students reported perceiving a greater importance of public health to nearly every medical specialty ( P < .001), more positive attitudes toward public health broadly ( P < .001), and increased knowledge of public health content ( P < .001). These findings were consistent across longitudinal analysis of students throughout the year-long course and when compared to the cohort who did not complete the modules. CONCLUSIONS: Case-based, interactive, and longitudinal public health content can be effectively integrated into the required undergraduate medical education curriculum to improve all medical students' knowledge and perceptions of public health. Incorporating evidence-based public health education into medical training may help future physicians to better address the needs of the communities and populations in which they practice.

Association of celiac disease with eosinophilic esophagitis: Nationwide register-based cohort study with sibling analyses.

Background: Celiac disease (CeD) is associated with several immune-mediated disorders, but it is unclear whether it is associated with eosinophilic esophagitis (EoE). Objective: We sought to examine the risk of EoE in patients with biopsy-verified CeD compared with matched controls and siblings. Methods: Using nationwide population-based histopathology data, we identified 27,338 patients with CeD diagnosed in the period 2002 to 2017 in Sweden. Patients with CeD were age- and sex-matched with up to 5 reference individuals (n = 134,987) from the general population. Cox Regression was used to estimate hazard ratios (HRs) for developing biopsy-verified EoE. In a secondary analysis, we used unaffected siblings of patients with CeD as comparators to adjust for intrafamilial confounding. Results: The median age at CeD diagnosis was 27 years, and 63.3% were female patients. During a median follow-up of 8.1 years, 17 patients with CeD and 13 matched reference individuals were diagnosed with EoE. This corresponded to incidence rates of 0.08 versus 0.01 per 1000 person-years, respectively, and an adjusted HR for EoE of 6.65 (95% CI, 3.26-13.81). Compared with their siblings without CeD, patients with CeD were however at a no increased risk of EoE (HR, 1.39; 95% CI, 0.55-3.51). Conclusions: In this study, individuals with CeD were at a 6.6-fold increased risk of later EoE compared with the general population. This association might be explained by an altered health-seeking behavior or through shared genetic or early environmental factors because the excess risk disappeared in sibling analyses.

A computer-aided polyp detection system in screening and surveillance colonoscopy: an international, multicentre, randomised, tandem trial.

BACKGROUND: Studies on the effect of computer-aided detection (CAD) in a daily clinical screening and surveillance colonoscopy population practice are scarce. The aim of this study was to evaluate a novel CAD system in a screening and surveillance colonoscopy population. METHODS: This multicentre, randomised, controlled trial was done in ten hospitals in Europe, the USA, and Israel by 31 endoscopists. Patients referred for non-immunochemical faecal occult blood test (iFOBT) screening or surveillance colonoscopy were included. Patients were randomomly assigned to CAD-assisted colonoscopy or conventional colonoscopy; a subset was further randomly assigned to undergo tandem colonoscopy: CAD followed by conventional colonoscopy or conventional colonoscopy followed by CAD. Primary objectives included adenoma per colonoscopy (APC) and adenoma per extraction (APE). Secondary objectives included adenoma miss rate (AMR) in the tandem colonoscopies. The study was registered at ClinicalTrials.gov, NCT04640792. FINDINGS: A total of 916 patients were included in the modified intention-to-treat analysis: 449 in the CAD group and 467 in the conventional colonoscopy group. APC was higher with CAD compared with conventional colonoscopy (0·70 vs 0·51, p=0·015; 314 adenomas per 449 colonoscopies vs 238 adenomas per 467 colonoscopies; poisson effect ratio 1·372 [95% CI 1·068-1·769]), while showing non-inferiority of APE compared with conventional colonoscopy (0·59 vs 0·66; p<0·001 for non-inferiority; 314 of 536 extractions vs 238 of 360 extractions). AMR in the 127 (61 with CAD first, 66 with conventional colonoscopy first) patients completing tandem colonoscopy was 19% (11 of 59 detected during the second pass) in the CAD first group and 36% (16 of 45 detected during the second pass) in the conventional colonoscopy first group (p=0·024). INTERPRETATION: CAD increased adenoma detection in non-iFOBT screening and surveillance colonoscopies and reduced adenoma miss rates compared with conventional colonoscopy, without an increase in the resection of non-adenomatous lesions. FUNDING: Magentiq Eye.

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

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