Routine duodenal biopsies to diagnose celiac disease

Diagnosing coeliac disease: A literature review

Coeliac disease (CD) is an autoimmune gastroenteropathy triggered by gliadin and gliadin-tissue transglutaminase (tTG) complexes. CD is one of the few autoimmune diseases with an accurate, non-invasive serological test. Anti-endomysial, anti-tTG and anti-deaminated gliadin peptides (DGP) antibodies are currently used for serological tests with tTG ELISAs being the superior test. Duodenal biopsy, although invasive, is the gold standard for CD diagnosis. HLA genotyping and flow cytometry can also be used as supplementary tests. The incidence of CD is rising globally although the reasons for this remain unclear. In addition, the true incidence of coeliac disease in African populations remains unknown although recent work suggests that South African populations express the alleles associated with this disease. This review examines the pathogenesis and diagnosis of coeliac disease and considers novel and innovative biomarkers in its diagnosis specifically in an African population.

Correlation of TTG IgA Level with Small Intestinal Histopathological Changes for Celiac Disease among Adult Saudi Patients

Background and objectives

According to recent guidelines, a diagnosis of celiac disease (CD) can be made without a biopsy, especially in children. There are no enough studies despite high prevalence and differences in genetic, race, and cultures. Therefore, we examined the correlation between tissue transglutaminase (TTG) and duodenal biopsy changes in our region because we are identical and different from others in culture, environment, and habits, and the correlation is same as that in different regions.

Methods

A retrospective cohort study at the Ministry of National Guard Health Affaires (NGHA) health care facilities that are distributed throughout kingdom of Saudi Arabia from April 19, 2015, till March 29, 2018. This study used the BESTCARE system that includes data from all NGHA facilities; data from 513 patients with CD were collected. All patients diagnosed with celiac disease aged 15 years or more, confirmed by improvement on gluten-free diet (GFD), and were not on GFD before endoscopy or serology test or both of them were included in the study, and the TTG IgA level was measured at the same time or within 2–3 months of biopsy date. The exclusion criteria were negative duodenal biopsy, which is less than 2; patients with negative biopsy and negative serology; patients who were on GFD before testing, and any patients known to have immunity diseases or illness causing mucosal changes. The TTG IgA level was measured in IU/ mL and was labeled as negative (<20 IU/mL) and positive (≥ 20 IU/mL) based on the cutoff value. However, Intestinal biopsy findings were identified as Marsh classification groups.

Results

One hundred thirty-four patients who met the inclusion criteria were included in the study. Median age of our sample was 24 years (16–37 years). Among these, 99 (73.88%) were female patients, whereas male patients were only 35 (26.12%). Histopathologic investigation of intestinal biopsy were Marsh 0 group was 16 cases (11.9%), Marsh 1 group was 8 cases (6%), Marsh 2 group was 4 cases (3%), Marsh 3a group was 32 cases (23.9%), Marsh 3b group was 64 cases (47.8%), and Marsh 3c group was 10 cases (7.5%). The TTG IgA antibody serology groups were <20 IU/mL in 13 cases (9.7%) and ≥20 IU/mL in 121 cases (90.3%). Among all patients with CD who had negative biopsy (Marsh 0 group), 16 (100%) of them had positive TTG IgA antibody. However, among patients with Marsh 1 group biopsy, 5 (62.5%) cases had negative TTG IgA antibody compared with 3 (37.5%) positive cases. Of the four cases (100%) with Marsh 2 group, all of them had positive TTG IgA antibody. However, in Marsh 3a group biopsy, 3 (9.4%) cases had negative TTG IgA antibody compared with 29 (90.6%) cases with positive TTG IgA antibody. Furthermore, among the patients with Marsh 3b group biopsy, 5 (7.8%) had negative antibody and 59 (92.2%) had positive serology. Of all biopsies of Marsh 3c group, 10 (100 %) had positive TTG IgA antibody.

Conclusions

In perspective of high prevalence of CD in KSA, even more than western countries, we can pretend that positive TTG antibody tests can be applied for the diagnosis of CD without biopsy, particularly in symptomatic patients along with high titer, that is, 5–10 times the upper limit of normal (ULN). However, to validate it further, we need larger prospective studies in which duodenal biopsies should be taken according to recommended protocol and should be interpreted by experienced pathologist. Furthermore, biopsy is still needed in patients who do not show clinical improvement on a gluten-free diet and in cases with mildly or moderately elevated TTG IgA.

Diagnosing coeliac disease: Out with the old and in with the new?

Coeliac disease (CD) is a complex condition resulting from an interplay between genetic and environmental factors. When diagnosing the condition, serological testing and genotyping are useful in excluding CD, although the gold standard of testing is currently histopathological examination of the small intestine. There are drawbacks associated with this form of testing however and because of this, novel forms of testing are currently under investigation. Before we develop completely novel tests though, it is important to ask whether or not we can simply use the data we gather from coeliac patients more effectively and build a more accurate snapshot of CD through statistical analysis of combined metrics. It is clear that not one single test can accurately diagnose CD and it is also clear that CD patients can no longer be defined by discrete classifications, the continuum of patient presentation needs to be recognised and correctly captured to improve diagnostic accuracy. This review will discuss the current diagnostics for CD and then outline novel diagnostics under investigation for the condition. Finally, improvements to current protocols will be discussed with the need for a holistic "snapshot" of CD using a number of metrics simultaneously.

Automated Detection of Celiac Disease on Duodenal Biopsy Slides: A Deep Learning Approach

CONTEXT

Celiac disease (CD) prevalence and diagnosis have increased substantially in recent years. The current gold standard for CD confirmation is visual examination of duodenal mucosal biopsies. An accurate computer-aided biopsy analysis system using deep learning can help pathologists diagnose CD more efficiently.

SUBJECTS AND METHODS

In this study, we trained a deep learning model to detect CD on duodenal biopsy images. Our model uses a state-of-the-art residual convolutional neural network to evaluate patches of duodenal tissue and then aggregates those predictions for whole-slide classification. We tested the model on an independent set of 212 images and evaluated its classification results against reference standards established by pathologists.

RESULTS

Our model identified CD, normal tissue, and nonspecific duodenitis with accuracies of 95.3%, 91.0%, and 89.2%, respectively. The area under the receiver operating characteristic curve was >0.95 for all classes.

CONCLUSIONS

We have developed an automated biopsy analysis system that achieves high performance in detecting CD on biopsy slides. Our system can highlight areas of interest and provide preliminary classification of duodenal biopsies before review by pathologists. This technology has great potential for improving the accuracy and efficiency of CD diagnosis.

Diagnostic yield of endoscopic markers for celiac disease

RATIONALE

In the setting of open access endoscopy, the recognition of suggestive endoscopic features in the duodenum can select patients with probability of celiac disease (CD). This could add to the current efforts to increase the diagnostic rate of this disease.

AIM

The aim of this study was to evaluate the diagnostic accuracy of these markers for CD in an adult population undergoing endoscopy, without a prior serological testing.

METHODS AND RESULTS

Over a period of 3 years, between June 2012 and 2015, all the patients who underwent upper gastrointestinal endoscopy and presented one or more of the endoscopic markers consistent with CD, or those suspected for CD, irrespective of the presence of these markers, were included. Sensitivity, specificity, positive and negative predictive values were calculated for these markers in CD diagnosis. Among the 182 patients, 56.04% were females, with a mean age of 47.6 ± 13.9 years. 20/182 (10.99%) had a final diagnosis of CD. The presence of any endoscopic marker had a high sensitivity (95%) and a negative predictive value (98.41%). Bulb atrophy and reduced folds in the descending duodenum had a low diagnostic accuracy, while scalloping, mosaic pattern and fissures were highly specific for CD (98.77%, 99.38% and 98.77%) and their presence greatly increased the probability of CD, with a positive likelihood ratio of 24.3, 24.3 and 12.15, respectively.

DISCUSSIONS

A wide set of endoscopic markers, including the duodenal bulb, were evaluated in this study. Our results showed that the endoscopy with a careful examination of the duodenum is a sensitive indicator for CD.

ABBREVIATIONS

CD = celiac disease, GI = gastrointestinal, VA = villous atrophy, NSAID = nonsteroidal anti-inflammatory drug, Sn = sensitivity, Sp = specificity, PPV = positive predictive value, NPV = negative predictive value, AUC = area under the curve, ROC = receiver operating characteristics, WLE = white light endoscopy, NBI = narrow band imaging, tTG = tissue transglutaminase, EMA = anti-endomysial antibodies.