Is duodenal biopsy always necessary for the diagnosis of coeliac disease in adult patients with high anti-tissue transglutaminase (TTG) antibody titres?

Non-biopsy Strategy for the Diagnosis of Celiac Disease in Adults: A Narrative Review

Celiac disease (CeD) diagnosis is a complicated process, requiring a multi-step procedure and a high level of clinical knowledge. Some scientific societies, mainly from Europe and North America, have proposed appropriate guidelines for the diagnosis and management of CeD. Since duodenal biopsy is particularly challenging for children, guidelines of the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition, presented in 2012 and updated in 2020, have made it possible to avoid the biopsy in symptomatic pediatric patients with high levels of IgA anti-transglutaminase. Several parallel, similar studies in adults support the non-biopsy strategy. However, several pros and cons exist in applying such a strategy. The present narrative review reports the current evidence and the implication of omitting biopsy in the diagnosis of CeD in adults.

Accuracy of the No-Biopsy Approach for the Diagnosis of Celiac Disease in Adults: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Current international guidelines recommend duodenal biopsies to confirm the diagnosis of celiac disease in adult patients. However, growing evidence suggests that immunoglobulin A (IgA) anti-tissue transglutaminase (tTg) antibody levels ≥10 times the upper limit of normal (ULN) can accurately predict celiac disease, eliminating the need for biopsy. We performed a systematic review and meta-analysis to evaluate the accuracy of the no-biopsy approach to confirm the diagnosis of celiac disease in adults.

METHODS

We systematically searched MEDLINE, EMBASE, Cochrane Library, and Web of Science from January 1998 to October 2023 for studies reporting the sensitivity and specificity of IgA-tTG ≥10×ULN against duodenal biopsies (Marsh grade ≥2) in adults with suspected celiac disease. We used a bivariate random effects model to calculate the summary estimates of sensitivity, specificity, and positive and negative likelihood ratios. The positive and negative likelihood ratios were used to calculate the positive predictive value of the no-biopsy approach across different pretest probabilities of celiac disease. The methodological quality of the included studies was evaluated using the QUADAS-2 tool. This study was registered with PROSPERO, number CRD42023398812.

RESULTS

A total of 18 studies comprising 12,103 participants from 15 countries were included. The pooled prevalence of biopsy-proven celiac disease in the included studies was 62% (95% confidence interval [CI], 40%-83%). The proportion of patients with IgA-tTG ≥10×ULN was 32% (95% CI, 24%-40%). The summary sensitivity of IgA-tTG ≥10×ULN was 51% (95% CI, 42%-60%), and the summary specificity was 100% (95% CI, 98%-100%). The area under the summary receiver operating characteristic curve was 0.83 (95% CI, 0.77 - 0.89). The positive predictive value of the no-biopsy approach to identify patients with celiac disease was 65%, 88%, 95%, and 99% if celiac disease prevalence was 1%, 4%, 10%, and 40%, respectively. Between-study heterogeneity was moderate (I2 =30.3%), and additional sensitivity analyses did not significantly alter our findings. Only 1 study had a low risk of bias across all domains.

CONCLUSION

The results of this meta-analysis suggest that selected adult patients with IgA-tTG ≥10×ULN and a moderate to high pretest probability of celiac disease could be diagnosed without undergoing invasive endoscopy and duodenal biopsy.

Validation of no-biopsy pathway for the diagnosis of celiac disease in Asian adults: a multicenter retrospective study

BACKGROUND AND AIM

While European Society of Pediatric Gastroenterology Hepatology and Nutrition advocates a no-biopsy pathway for the diagnosis of celiac disease (CeD) in children if IgA anti-tissue transglutaminase antibody (anti-tTG ab) titer is ≥10-fold upper limit of normal (ULN) and have a positive IgA anti-endomysial antibody (EMA); the data for anti-tTG Ab titer-based diagnosis of CeD in adults is still emerging. We planned to validate if IgA anti-tTG Ab titer ≥10-fold predicts villous abnormalities of modified Marsh grade ≥2 in Asian adult patients with CeD.

METHODS

We recruited 937 adult patients with positive anti-tTG Ab from two databases, including AIIMS Celiac Clinic and Indian National Biorepository. The diagnosis of definite CeD was made on the basis of a positive anti-tTG Ab and the presence of villous abnormalities of modified Marsh grade ≥2.

RESULTS

Of 937 adult patients with positive anti-tTG Ab, 889 (91.2%) showed villous abnormalities of modified Marsh grade ≥2. Only 47.6% of 889 adults with CeD had anti- tTG Ab titers of ≥10-fold. The positive predictive value (PPV) and specificity of anti tTG Ab titer ≥10-fold for predicting modified Marsh grade ≥2 were 99.8% and 98%, respectively. At anti-tTG Ab titer ≥11-fold, specificity and PPV were 100% for predicting villous abnormalities of modified Marsh grade ≥2.

CONCLUSIONS

Approximately 50% of adults with CeD may benefit from the no biopsy pathway, reducing the health burden and risks of gastroscopy/anesthesia.

The Correlation Between Serum Anti-tissue Transglutaminase (Anti-tTG) Antibody Levels and Histological Severity of Celiac Disease in Adolescents and Adults: A Meta-Analysis

Celiac disease is an autoimmune disorder characterized by a broad spectrum of histological damage to the intestinal mucosa. Comprehension and understanding of the association between anti-tissue transglutaminase (anti-tTG) antibody levels and the histological severity of celiac disease are not well established, prompting the need for meta-analysis. This study aims to offer insights into the diagnostic abilities of anti-tTG antibody levels in determining the histological severity of celiac disease by providing quantitative evidence based on a diverse range of studies. An extensive search was conducted across four electronic research databases to identify primary research articles reporting serum anti-tTG antibody levels in correlation with different Marsh grades, signifying the histological severity of celiac disease. The software tool RevMan 5.4 (the Cochrane Collaboration, London, UK) was used to compile standardized mean differences (SMD) alongside their respective confidence intervals. A total of 13 studies were included in the meta-analysis, with a patient pool of 2505 patients. Marsh grade I and II were found to have higher anti-tTG antibody levels compared to those with grade 0 (SMD 1.50; 95% CI: 1.12, 1.87; p-value <0.00001). Antibody levels were higher in Marsh grade IIIa when compared to both grade 0 (SMD 0.97; 95% CI: 0.67, 1.28; p-value <0.00001) and grade ≤2 (SMD 0.61; 95% CI: 0.44, 0.79; p-value <0.00001). Patients with Marsh IIIb also reported greater anti-tTG levels compared to grade 0 (SMD 1.48; 95% CI: 0.99, 1.96; p-value <0.00001) and grade ≤2 (SMD 0.98; 95% CI: 0.79, 1.18; p-value <0.00001). Likewise, Marsh grade ≥IIIc reported high levels of anti-tTG antibodies in comparison with grade 0 (SMD 1.06; 95% CI: 0.72, 1.39; p-value <0.00001) and grade ≤2 (SMD 1.18; 95% CI: 1.02, 1.34; p-value <0.00001). Our meta-analysis revealed a consistent, robust correlation between anti-tTG antibody levels and the histological severity of celiac disease, with a clear trend of increasing antibody levels corresponding to the severity of mucosal damage. Large-scale primary research initiatives are needed to reach definitive conclusions.

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.

No-biopsy diagnostic approach to coeliac disease

This brief review outlines contributions that Michael Marsh and others made to understanding the structure and function of the upper small bowel mucosa and the formation of abnormalities that occur in coeliac disease (CD). He introduced his classification of lesions 30 years ago that has been widely adopted. The development and use of serological tests to screen for and diagnose CD in children and adults without the need for a small bowel biopsy in a considerable proportion is also recognised and will gain traction.

The differential diagnoses for severe enteropathy or severely damaged small intestinal mucosa

Aim

The aim of this study was to explore the aetiology of severe duodenal mucosal abnormality in consecutive patients who underwent gastroscopy and duodenal biopsy over the past 10 years.

Background

A range of differential diagnoses have been reported for severe duodenal architectural distortion.

Methods

Clinical and laboratory data of all the patients with severe duodenal architectural distortion diagnosed at MidCentral District Health Board (DHB), New Zealand were collected and statistically analysed. Ninety-five percent confidence intervals (CI) are shown.

Results

Between September 2009 and April 2019, 229 patients were diagnosed with severe enteropathy. The median patient age was 41 years (range 6-83 years). Two hundred and twenty-four of these patients (97.8%, 95.0-99.3%) were diagnosed with coeliac disease (CeD), with one of these patients having gluten induced T-cell lymphoma. From the remaining five patients, one had a diagnosis of tropical sprue and four did not have a clear aetiology. There were 180 patients from 191 (94.2%, 89.9-97.1%) with at least one positive coeliac marker, all with a diagnosis of CeD. Eleven patients (5.8% of 191, 2.9-10.1%) had negative markers for both tissue transglutaminase IgA (tTG-IgA) and IgA-endomysial antibodies (EMA-IgA) with six having a diagnosis of seronegative CeD.

Conclusion

Although the spectrum of histological changes in CeD may range from normal to a flat mucosa, severe duodenal architectural distortion seems to occur mainly in CeD. Idiopathic enteropathy was recorded as the second but by far less frequent presentation of severe enteropathy. This study highlights that infection and other aetiologies are rarely implicated in severe enteropathy, with one case (0.4%) of refractory CeD/T-cell lymphoma.

Advances in Imaging of Inflammation, Fibrosis, and Cancer in the Gastrointestinal Tract

Gastrointestinal disease is prevalent and broad, manifesting itself in a variety of ways, including inflammation, fibrosis, infection, and cancer. However, historically, diagnostic technologies have exhibited limitations, especially with regard to diagnostic uncertainty. Despite development of newly emerging technologies such as optoacoustic imaging, many recent advancements have focused on improving upon pre-existing modalities such as ultrasound, computed tomography, magnetic resonance imaging, and endoscopy. These advancements include utilization of machine learning models, biomarkers, new technological applications such as diffusion weighted imaging, and new techniques such as transrectal ultrasound. This review discusses assessment of disease processes using imaging strategies for the detection and monitoring of inflammation, fibrosis, and cancer in the context of gastrointestinal disease. Specifically, we include ulcerative colitis, Crohn's disease, diverticulitis, celiac disease, graft vs. host disease, intestinal fibrosis, colorectal stricture, gastric cancer, and colorectal cancer. We address some of the most recent and promising advancements for improvement of gastrointestinal imaging, including unique discussions of such advancements with regard to imaging of fibrosis and differentiation between similar disease processes.

Multiple-instance-learning-based detection of coeliac disease in histological whole-slide images

We present a multiple-instance-learning-based scheme for detecting coeliac disease, an autoimmune disorder affecting the intestine, in histological whole-slide images (WSIs) of duodenal biopsies. We train our model to detect 2 distinct classes, normal tissue and coeliac disease, on the patch-level, and in turn leverage slide-level classifications. Using 5-fold cross-validation in a training set of 1841 (1163 normal; 680 coeliac disease) WSIs, our model classifies slides as normal with accuracy (96.7±0.6)%, precision (98.0±1.7)%, and recall (96.8±2.5)%, and as coeliac disease with accuracy (96.7±0.5)%, precision (94.9±3.7)%, and recall (96.5±2.9)% where the error bars are the cross-validation standard deviation. We apply our model to 2 test sets: one containing 191 WSIs (126 normal; 65 coeliac) from the same sources as the training data, and another from a completely independent source, containing 34 WSIs (17 normal; 17 coeliac), obtained with a scanner model not represented in the training data. Using the same-source test data, our model classifies slides as normal with accuracy 96.5%, precision 98.4% and recall 96.1%, and positive for coeliac disease with accuracy 96.5%, precision 93.5%, and recall 97.3%. Using the different-source test data the model classifies slides as normal with accuracy 94.1% (32/34), precision 89.5%, and recall 100%, and as positive for coeliac disease with accuracy 94.1%, precision 100%, and recall 88.2%. We discuss generalising our approach to screen for a range of pathologies.

Upper Gastrointestinal Tract Associated Lesions in Patients with Newly Diagnosed Celiac Disease

(1) Background: Currently available guidelines require upper gastrointestinal (GI) endoscopy with biopsy sampling for adult celiac disease (CD) diagnosis. Based on the pediatric experience, there has been a growing interest if serology-based diagnosis would be possible for adult CD also. Our aim was to analyze the associated upper GI tract lesions in newly diagnosed CD patients, to see if significant associated pathology is detected during index endoscopy, which might impact patient management not related to CD. (2) Methods: We performed a retrospective analysis of newly diagnosed CD cases diagnosed over a period of 7 years (2014–2020). Demographic, clinical, laboratory, endoscopy and histopathology data were collected from the patients’ charts. Diagnosis was set according to ACG Guideline 2013. (3) Results: Altogether 79 patients were recruited for this study purpose, 75.9% female, median age 39 years. All patients had positive CD-specific serology and atrophic mucosal injury in duodenal biopsy samples. Besides villous atrophy, associated endoscopic findings were detected in 42/79 (53.16%) of patients. Most of the gastric lesions were minor endoscopic findings—small sliding hiatal hernias, non-specific chronic gastritis, but we also found two cases of peptic ulcers, one case of metaplastic gastritis, six cases of atrophic gastritis and one subepithelial lesion. Only one patient had changes in the duodenum except CD-related findings—an inflammatory polyp in the duodenal bulb. No malignancies were found. (4) Conclusions: In our cohort, there was a significant number of newly diagnosed CD patients who had associated lesions during the index upper GI endoscopy, but most of them were minor endoscopic findings.