Quantitative histology-based classification system for assessment of the intestinal mucosal histological changes in patients with celiac disease

CD, or not CD, that is the question: a digital interobserver agreement study in coeliac disease

OBJECTIVE

Coeliac disease (CD) diagnosis generally depends on histological examination of duodenal biopsies. We present the first study analysing the concordance in examination of duodenal biopsies using digitised whole-slide images (WSIs). We further investigate whether the inclusion of immunoglobulin A tissue transglutaminase (IgA tTG) and haemoglobin (Hb) data improves the interobserver agreement of diagnosis.

DESIGN

We undertook a large study of the concordance in histological examination of duodenal biopsies using digitised WSIs in an entirely virtual reporting setting. Our study was organised in two phases: in phase 1, 13 pathologists independently classified 100 duodenal biopsies (40 normal; 40 CD; 20 indeterminate enteropathy) in the absence of any clinical or laboratory data. In phase 2, the same pathologists examined the (re-anonymised) WSIs with the inclusion of IgA tTG and Hb data.

RESULTS

We found the mean probability of two observers agreeing in the absence of additional data to be 0.73 (±0.08) with a corresponding Cohen's kappa of 0.59 (±0.11). We further showed that the inclusion of additional data increased the concordance to 0.80 (±0.06) with a Cohen's kappa coefficient of 0.67 (±0.09).

CONCLUSION

We showed that the addition of serological data significantly improves the quality of CD diagnosis. However, the limited interobserver agreement in CD diagnosis using digitised WSIs, even after the inclusion of IgA tTG and Hb data, indicates the importance of interpreting duodenal biopsy in the appropriate clinical context. It further highlights the unmet need for an objective means of reproducible duodenal biopsy diagnosis, such as the automated analysis of WSIs using artificial intelligence.

Role of Serology, Dietary Assessment, and Fecal Gluten Immunogenic Peptides for Predicting Histologic Recovery in Children with Celiac Disease

BACKGROUND

A strict lifelong gluten-free diet (GFD) remains the only treatment of celiac disease (CD). Adherence to gluten-free diet is best reflected by mucosal healing. Noninvasive tools capable of predicting mucosal recovery in CD patients need to be identified.

AIMS

To compare the ability of various modalities used to assess compliance to GFD, for predicting persistent mucosal damage in children with CD.

METHODS

A prospective, single-center, observational study on children with CD on a GFD was conducted between January 2020 and April 2021. Children with CD on GFD were consecutively enrolled and various modalities used to assess adherence to GFD were compared.

RESULTS

One hundred and fifty children (Mean age 12.2 ± 3.6 years, 58% Boys) on GFD (Mean duration 6 ± 3.1 years) were enrolled in the study. Persistent mucosal damage was seen in 88% of the enrolled. Fecal gluten immunogenic peptide (GIP) was positive in 87.8% (129/147). Antibodies to tissue transglutaminase (TGA-IgA) and/or deamidated gliadin peptide (DGP) were positive in 32% (48/150) whereas antibody to synthetic neoepitopes of TGA-IgA was positive in 24.8% (37/149). Non-compliance as assessed by local questionnaire, Biagi score, and dietitian detailed interview were 62.7%, 60%, and 75.3%, respectively. Serology had the highest specificity (83%) and fecal GIP had the highest sensitivity (89%). On logistic regression analysis, only non-compliance by Biagi score predicted poor mucosal recovery.

CONCLUSION

Fecal GIP may be sensitive to detect only "one-point dietary transgression." None of the existing modalities used to assess compliance to GFD accurately predict persistent mucosal damage. A subset of patients may develop gluten tolerance.

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.

The Role of Nerve Fibers in the Tumor Immune Microenvironment of Solid Tumors

The importance of neurons and nerve fibers in the tumor microenvironment (TME) of solid tumors is now acknowledged after being unexplored for a long time; this is possible due to the development of new technologies that allow in situ characterization of the TME. Recent studies have shown that the density and types of nerves that innervate tumors can predict a patient's clinical outcome and drive several processes of tumor biology. Nowadays, several efforts in cancer research and neuroscience are taking place to elucidate the mechanisms that drive tumor-associated innervation and nerve-tumor and nerve-immune interaction. Assessment of neurons and nerves within the context of the TME can be performed in situ, in tumor tissue, using several pathology-based strategies that utilize histochemical and immunohistochemistry principles, hi-plex technologies, and computational pathology approaches to identify measurable histopathological characteristics of nerves. These features include the number and type of tumor associated nerves, topographical location and microenvironment of neural invasion of malignant cells, and investigation of neuro-related biomarker expression in nerves, tumor cells, and cells of the TME. A deeper understanding of these complex interactions and the impact of nerves in tumor biology will guide the design of better strategies for targeted therapy in clinical trials.

Case Report: Morphologic and Functional Characteristics of Intestinal Mucosa in a Child With Short Bowel Syndrome After Treatment With Teduglutide: Evidence in Favor of GLP-2 Analog Safety

Teduglutide is a glucagon-like peptide-2 (GLP-2) analog employed in patients with short bowel syndrome (SBS) to reduce the need of parenteral nutrition in these patients, by virtue of its effects on enteric function. The experimental studies reported that the stimulating action of GLP-2 on epithelial turnover implies the potential development of dysplastic and neoplastic lesion. However, the clinical trials could not detect preneoplastic lesions on histologic material, and in a recent pilot study the occurrence of polyps was similar before and after treatment and included only low-grade dysplastic lesions. Another clue in GLP-2 function in stimulating mucosal restore is its enhancement through cooperation with epidermal growth factor (EGF). In this study, we analyzed gastroscopy and colonoscopy samplings from a child successfully weaned off parenteral nutrition with teduglutide. Villous and crypt structure was regular both in duodenal and in colonic samplings; in properly oriented villi, villus/crypt ratio was regular. The absorptive epithelium demonstrated a regular morphology. No atypia was detected in enterocytes, along epithelial structures. At the ultrastructural analysis, only a few enterocytes with vacuolized cytoplasm were observed. An S-phase marker Ki67 stained nuclei in the transitional amplifying zone, while nuclei stained by the cell cycle regulatory proteins p21 and p27 were placed in the differentiated epithelium of the duodenal villi and colonic crypts, as in the control cases. The counts of enterocytes immunostained with the same antisera, evaluated with image analysis software, were in the range of control cases. The ratio of the number of epidermal growth factor receptor (EGFR) signals/the number of centromere probe of chromosome 7 (CEP7) signals was less than 2. The findings available from this single patient are consistent with good preservation of functional capability of intestinal epithelium after treatment with GLP-2, given the histologic and ultrastructural features of enterocytes. In addition, the findings from cell cycle regulatory proteins immunolocalization and quantitative analysis show that cell renewal machinery in our case is comparable to control cases. The gene of the receptor EGFR is regularly expressed in enteric epithelium of our case. Morphologic and functional data from our patient improve evidence in favor of the safety of GLP-2 employ in SBS.

Gluten Induces Subtle Histological Changes in Duodenal Mucosa of Patients with Non-Coeliac Gluten Sensitivity: A Multicentre Study

Background: Histological changes induced by gluten in the duodenal mucosa of patients with non-coeliac gluten sensitivity (NCGS) are poorly defined. Objectives: To evaluate the structural and inflammatory features of NCGS compared to controls and coeliac disease (CeD) with milder enteropathy (Marsh I-II). Methods: Well-oriented biopsies of 262 control cases with normal gastroscopy and histologic findings, 261 CeD, and 175 NCGS biopsies from 9 contributing countries were examined. Villus height (VH, in μm), crypt depth (CrD, in μm), villus-to-crypt ratios (VCR), IELs (intraepithelial lymphocytes/100 enterocytes), and other relevant histological, serologic, and demographic parameters were quantified. Results: The median VH in NCGS was significantly shorter (600, IQR: 400−705) than controls (900, IQR: 667−1112) (p < 0.001). NCGS patients with Marsh I-II had similar VH and VCR to CeD [465 µm (IQR: 390−620) vs. 427 µm (IQR: 348−569, p = 0·176)]. The VCR in NCGS with Marsh 0 was lower than controls (p < 0.001). The median IEL in NCGS with Marsh 0 was higher than controls (23.0 vs. 13.7, p < 0.001). To distinguish Marsh 0 NCGS from controls, an IEL cut-off of 14 showed 79% sensitivity and 55% specificity. IEL densities in Marsh I-II NCGS and CeD groups were similar. Conclusion: NCGS duodenal mucosa exhibits distinctive changes consistent with an intestinal response to luminal antigens, even at the Marsh 0 stage of villus architecture.

The global burden of coeliac disease: opportunities and challenges

Coeliac disease is a systemic disorder characterized by immune-mediated enteropathy, which is caused by gluten ingestion in genetically susceptible individuals. The clinical presentation of coeliac disease is highly variable and ranges from malabsorption through solely extra-intestinal manifestations to asymptomatic. As a result, the majority of patients with coeliac disease remain undiagnosed, misdiagnosed or experience a substantial delay in diagnosis. Coeliac disease is diagnosed by a combination of serological findings of disease-related antibodies and histological evidence of villous abnormalities in duodenal biopsy samples. However, variability in histological grading and in the diagnostic performance of some commercially available serological tests remains unacceptably high and confirmatory assays are not readily available in many parts of the world. Currently, the only effective treatment for coeliac disease is a lifelong, strict, gluten-free diet. However, many barriers impede patients' adherence to this diet, including lack of widespread availability, high cost, cross-contamination and its overall restrictive nature. Routine follow-up is necessary to ensure adherence to a gluten-free diet but considerable variation is evident in follow-up protocols and the optimal disease management strategy is not clear. However, these challenges in the diagnosis and management of coeliac disease suggest opportunities for future research.

Artificial intelligence in small intestinal diseases: Application and prospects

The small intestine is located in the middle of the gastrointestinal tract, so small intestinal diseases are more difficult to diagnose than other gastrointestinal diseases. However, with the extensive application of artificial intelligence in the field of small intestinal diseases, with its efficient learning capacities and computational power, artificial intelligence plays an important role in the auxiliary diagnosis and prognosis prediction based on the capsule endoscopy and other examination methods, which improves the accuracy of diagnosis and prediction and reduces the workload of doctors. In this review, a comprehensive retrieval was performed on articles published up to October 2020 from PubMed and other databases. Thereby the application status of artificial intelligence in small intestinal diseases was systematically introduced, and the challenges and prospects in this field were also analyzed.

Best practices of handling, processing, and interpretation of small intestinal biopsies for the diagnosis and management of celiac disease: A joint consensus of Indian association of pathologists and microbiologists and Indian society of gastroenterology

The Indian Association of Pathologists and Microbiologists (IAPM) and Indian Society of Gastroenterology (ISG) decided to make a joint consensus recommendation for handling, processing, and interpretation of SI biopsies for the diagnosis and management of celiac disease (CD) recognizing the inhomogeneous practice of biopsy sampling, orientation, processing, and interpretation. A modified Delphi process was used to develop this consensus document containing a total of 42 statements and recommendations, which were generated by sharing the document draft, incorporating expert's opinion, followed by three cycles of electronic voting as well as a full-day face-to-face virtual ZOOM meeting and review of supporting literature. Of the 42 statements, 7 statements are on small intestinal (SI) biopsy in suspected patients of CD, site and the number of biopsies; 7 on handling, fixative, orientation, processing, and sectioning in pathology laboratories; 2 on histological orientation; 13 statements on histological interpretation and histological grading; 3 on the assessment of follow-up biopsies; 2 statements on gluten-free diet (GFD)-nonresponsive CD; 4 on challenges in the diagnosis of CD; 2 statements each on pathology reporting protocol and training and infrastructure in this area. The goal of this guideline document is to formulate a uniform protocol agreed upon both by the experienced pathologists and gastroenterologists to standardize the practice, improve the yield of small bowel biopsy interpretation, patients' compliance, overall management in CD, and generate unified data for patient care and research in the related field.

Opportunities and challenges in the management of celiac disease in Asia

Although once considered uncommon, there is increasing recognition of celiac disease (CeD) in Asia. It is now clear that CeD is a disorder as frequent in certain Asian countries as that in western countries, although it often remains undiagnosed. With increasing awareness and diagnosis, the absolute numbers of celiac patients are expected to increase markedly in Asia. Asia, with 60% of the population of the world, is probably the major "reservoir" of undiagnosed CeD in the world. As Asia has a huge landscape along with highly heterogenous genetic, social, cultural, and nutritional practices, similar heterogeneity is seen in the epidemiology, diagnostic, and therapeutic facilities for CeD in Asia. In this article, we have reviewed the changes in the epidemiology, diagnostics, and management of CeD in Asia and summarized the challenges and opportunities for its emergence in Asia.

Digital histology in celiac disease: A practice changer

Artificial intelligence (AI) has grown tremendously in the last decades and is undoubtedly the future era in medicine. Concerning digestive diseases, applications of AI include clinical gastroenterology, gastrointestinal endoscopy and imaging, and not least pathological diagnosis. Several gastrointestinal pathologies require histological confirmation for a positive diagnosis. Among them, celiac disease (CD) diagnosis has been in the spotlight over time, but controversy is still ongoing with regard to the so-called celiac-type histology. Despite efforts to improve histological diagnosis in CD, there are still several issues and pitfalls associated with duodenal histology reading. Several papers have assessed the accuracy of AI techniques in detecting CD on duodenal biopsy images and have shown high diagnostic performance over standard histology reading. We discuss the role of computer-assisted histology in improving the assessment of mucosal architectural injury and inflammation in CD patients, both for diagnosis and follow-up.