No-biopsy strategy for coeliac disease is applicable in adult patients: a 'real-world' Scottish experience

Measured levels of positive transglutaminase 2 antibodies are not associated with presentation or incidental endoscopic findings at celiac disease diagnosis

OBJECTIVES

It has been suggested that celiac disease could be diagnosed non-invasively in adults with transglutaminase antibody (TGA) levels >10x upper limit of normal (ULN). It is, however, unclear if high values signify more advanced disease and higher risk of co-morbidities. We investigated the association between the TGA levels, clinical characteristics and non-celiac endoscopic findings.

METHODS

Medical data on 450 celiac disease patients at diagnosis were collected. They were further divided into those with high positive (>10x ULN, n = 164), moderately positive (1-10x ULN, n = 219), and negative (n = 67) TGA.

RESULTS

Median age of patients was 50 years and 60% were women. Patients with negative TGA were older (median age 58 vs. 51 vs. 46 years respectively, p = 0.002) and had more often weight loss (27% vs. 10% vs. 9%, p < 0.001) and abdominal pain or dyspepsia (40% vs 27% vs. 22%, p = 0.017) than did those with moderately positive/high TGA. The groups did not differ in sex, BMI, or other symptoms. Major endoscopic findings included one esophageal adenocarcinoma presenting with dysphagia, six esophagitis, three gastric ulcers, and 39 H. Pylori or other active gastritis. High, moderately positive or negative TGA levels were not associated with these findings in crude or age-adjusted analyses.

CONCLUSIONS

Presentation was similar in patients with moderate or high levels of TGA, whereas patients with negative TGA were different. The level of TGA was not associated with incidental endoscopic findings and the only malignancy presented with an alarm symptom atypical to celiac disease.

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.

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.

Serum anti-tissue transglutaminase IgA and prediction of duodenal villous atrophy in adults with suspected coeliac disease without IgA deficiency (Bi.A.CeD): a multicentre, prospective cohort study

BACKGROUND

Whether coeliac disease in adults can be diagnosed with serology alone remains controversial. We aimed to evaluate the accuracy of serum anti-tissue transglutaminase IgA (tTG-IgA) in the diagnosis of coeliac disease.

METHODS

In this multicentre, prospective cohort study, adult participants (aged ≥18 years) with suspected coeliac disease without IgA deficiency who were not on a gluten-free diet and who had a local serum tTG-IgA measurement, were enrolled from Feb 27, 2018, to Dec 24, 2020, by 14 tertiary referral centres (ten from Europe, two from Asia, one from Oceania, and one from South America) to undergo local endoscopic duodenal biopsy. Local serum tTG-IgA was measured with 14 different test brands and concentration expressed as a multiple of each test's upper limit of normal (ULN), and defined as positive when greater than 1 times the ULN. The main study outcome was the reliability of serum tests for the diagnosis of coeliac disease, as defined by duodenal villous atrophy (Marsh type 3 or Corazza-Villanacci grade B). Histology was evaluated by the local pathologist, with discordant cases (positive tTG-IgA without duodenal villous atrophy or negative tTG-IgA with duodenal villous atrophy) re-evaluated by a central pathologist. The reliability of serum tests for the prediction of duodenal villous atrophy was evaluated according to sensitivity, specificity, positive predictive value, negative predictive value, and the area under the receiver operating characteristic curve (AUC) for categorical and continuous data.

FINDINGS

We enrolled 436 participants with complete local data on serum tTG-IgA and duodenal histology (296 [68%] women and 140 [32%] men; mean age 40 years [SD 15]). Positive serum tTG-IgA was detected in 363 (83%) participants and negative serum tTG-IgA in 73 (17%). Of the 363 participants with positive serum tTG-IgA, 341 had positive histology (true positives) and 22 had negative histology (false positives) after local review. Of the 73 participants with negative serum tTG-IgA, seven had positive histology (false negatives) and 66 had negative histology (true negatives) after local review. The positive predictive value was 93·9% (95% CI 89·2-98·6), the negative predictive value was 90·4% (85·5-95·3), sensitivity was 98·0% (95·3-100·0), and specificity was 75·0% (66·6-83·4). After central re-evaluation of duodenal histology in 29 discordant cases, there were 348 true positive cases, 15 false positive cases, 66 true negative cases, and seven false negative cases, resulting in a positive predictive value of 95·9% (92·0-99·8), a negative predictive value of 90·4% (85·5-95·3), a sensitivity of 98·0% (95·3-100·0), and a specificity of 81·5% (73·9-89·1). Either using the local or central definition of duodenal histology, the positive predictive value of local serum tTG-IgA increased when the serological threshold was defined at increasing multiples of the ULN (p<0·0001). The AUC for serum tTG-IgA for the prediction of duodenal villous atrophy was 0·87 (95% CI 0·81-0·92) when applying the categorical definition of serum tTG-IgA (positive [>1 × ULN] vs negative [≤1 × ULN]), and 0·93 (0·89-0·96) when applying the numerical definition of serum tTG-IgA (multiples of the ULN). Additional endoscopic findings included peptic gastritis (nine patients), autoimmune atrophic gastritis (three), reflux oesophagitis (31), gastric or duodenal ulcer (three), and Barrett's oesophagus (one). In the 1-year follow-up, a midgut ileum lymphoma was diagnosed in a woman on a gluten-free diet.

INTERPRETATION

Our data showed that biopsy could be reasonably avoided in the diagnosis of coeliac disease in adults with reliable suspicion of coeliac disease and high serum tTG-IgA.

FUNDING

None.

Cost-benefits and environmental impact of the no-biopsy approach for the diagnosis of coeliac disease in adults

Objective

Recent evidence suggests that adult patients with IgA tissue transglutaminase levels of ≥10× the upper limit of normal could be accurately diagnosed with coeliac disease without undergoing endoscopy and biopsy. We aimed to evaluate the cost-benefits and the environmental impact of implementing the no-biopsy approach for diagnosing coeliac disease in clinical practice.

Design

We calculated the overall direct and indirect costs of the conventional serology-biopsy approach and the no-biopsy approach for the diagnosis of coeliac disease based on the national average unit costs and the Office of National Statistics data. We further estimated the environmental impact of avoiding endoscopy based on the estimated greenhouse gas emissions from endoscopy.

Results

Approximately 3000 endoscopies for suspected coeliac disease could be avoided each year in the UK. Implementing the no-biopsy approach for the diagnosis of coeliac disease in adults could save the National Health Service over £2.5 million in direct and indirect costs per annum and reduce endoscopy carbon footprint by 87 tonnes of CO2 per year, equivalent to greenhouse gas emissions from driving 222 875 miles, carbon emissions from charging over 10 million smartphones and the carbon sequestrated by 1438 trees grown for 10 years.

Conclusion

The implementation of this non-invasive green approach could be an essential first step in the 'Reduce' strategy advocated by the British Society of Gastroenterology and other international endoscopy societies for sustainable endoscopy practice.

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.