Immunohistologic analysis of the duodenal bulb: a new method for celiac disease diagnosis in children

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.

Rapid immunochromatography on fresh intestinal biopsy is highly accurate in detecting intestinal anti-transglutaminase antibodies

OBJECTIVE

Intestinal anti-transglutaminase antibodies (I-Anti-TG2) are a specific marker of Celiac Disease (CeD). The aim of this study was to evaluate the diagnostic accuracy of a novel application of an immunochromatographic assay referred as Rapid_AntiTG2 to detect I-Anti-TG2 on intestinal biopsy lysate.

DESIGN

Consecutive pediatric patients referred to a single center for elective upper endoscopy were enrolled. Biopsies were taken from duodenal bulb and distal duodenum. For each sampling site 2 biopsies was analyzed for standard histology, 1 biopsy was cultured to perform the reference standard assay for I-Anti-TG2 detection (EMA-biopsy) and 1 biopsy was mechanically lysed to perform Rapid_AntiTG2. The primary outcome was the diagnostic accuracy of Rapid_AntiTG2 on biopsy lysate compared to the gold standard (serology + histopathology) for CeD diagnosis. The secondary outcome was the agreement of Rapid_AntiTG2 with EMA-biopsy.

RESULTS

148 patients were included. Of these 79 were CeD (64 Classical CeD, 2 Seronegative CeD and 13 Potential CeD) and 69 were controls. Rapid_AntiTG2 on biopsy lysate had a very high diagnostic accuracy (sensitivity 100%, specificity 97%, LR+34.1, LR- 0.01) in separating patients with CeD from controls. Diagnostic accuracy was unchanged in patients with potential and seronegative CeD. Rapid_AntiTG2 on biopsy lysate had almost perfect agreement with the EMA-biopsy reference test (99% agreement, Cohen's K .97).

CONCLUSION

I-Anti-TG2 can be detected with an immunochromatographic assay after simple mechanical lysis of fresh intestinal biopsy with very high diagnostic accuracy. The test is quick and easy to perform and can be widely available in any endoscopy unit. Its implementation would allow a better understanding of the prognostic value of I-Anti-TG2 and help clinicians in cases of suspected CeD that are difficult to classify.

A new double immunohistochemistry method to detect mucosal anti-transglutaminase IgA deposits in coeliac children

BACKGROUND

Intestinal transglutaminase (TG2) IgA deposits represent early marker of coeliac disease (CeD) and can predict the evolution towards intestinal atrophy.

AIMS

To validate a double immunohistochemistry method for the determination of intestinal TG2 IgA deposits on formalin-fixed paraffin-embedded biopsies.

METHODS

Immunohistochemistry was tested on: 1) children with overt CeD [persistently positive serum IgA anti-tissue transglutaminase type 2 (TGA-IgA) with moderate or low titer, and histological findings of CeD]; 2) potential CeD (persistently positive serum TGA-IgA and normal intestinal mucosa) and 3) controls (negative serum TGA-IgA and normal intestinal mucosa).

RESULTS

Samples from 61 children were analyzed (32 overt CeD, 14 potential CeD, and 15 controls). Deposits appeared as focal, multifocal, or confluent extracellular foci of red and brown staining colocalization in the sub-epithelium and around mucosal vessels. Deposits were present in all 32 children with overt CeD and in 9/14 potential CeD. Deposits were never observed in the 15 controls. Patients with higher serum level of TGA-IgA and with mucosal atrophy showed mostly a multifocal/diffuse pattern of deposits distribution. The bulb appeared most severely involved. In potential CeD deposits showed mainly a focal distribution.

CONCLUSION

Our results indicate double immunohistochemistry as promising diagnostic tool to improve diagnosis of CeD.

Histopathology of intestinal villi in neonatal and paediatric age: main features with clinical correlation - Part II

In this paper, we will continue the description of histological findings of infantile and paediatric small bowel alterations with the main clinical pictures and differential diagnosis. We emphasise once again the need to evaluate the biopsies in an adequate clinical contest and with a systematic approach, including epithelial alterations, lamina propria changes, mucosal architecture, and the distribution of inflammation, together with other morphological signs more specific of certain diseases. We describe the histological findings of coeliac and Crohn’s disease, gastrointestinal food allergic diseases, Langerhans cell histiocytosis, nutritional deficiencies and infections. Finally, we suggest the principal issues in the drafting the pathological report for appropriate interpretation and usefulness in clinical practice.

Histopathology of Celiac Disease. Position Statements of the Italian Group of Gastrointestinal Pathologists (GIPAD-SIAPEC)

Celiac Disease (CeD) is an immune-mediated inflammatory disorder of the small intestine, affecting genetically susceptible individuals when exposed to gluten. Small intestinal biopsy interpretation has been the “gold standard” for celiac disease (CeD) for over 50 years. Despite today’s availability of sensitive and specific serological tests, the histopathological features from mucosal biopsy play a key role in diagnosing when CeD is suspected. Such a diagnostic approach requires a multidisciplinary team to optimize both tissue sampling and interpretation via the interaction between the pathologist and the gastroenterologist. Pathologists of the Italian Group of Gastrointestinal Pathology (GIPAD-SIAPEC), together with a member (TR) of the Italian Society of Technicians (AITIC) and an expert gastroenterologist (CC), provide position statements as a practical tool for reading and interpreting the report.

Moreover, a position statement was formulated about the recently described condition known as Non-Celiac Gluten Sensitivity (NCGS). Within such a diagnostic setting, both the architectural abnormalities of the duodenal mucosa, namely glandular hyperplasia, and villous atrophy and the number of intraepithelial T-lymphocytes should be well highlighted. Ancillary tests such as anti-CD3 stain are useful for an accurate count of the intraepithelial T lymphocytes when CeD or NCGS is suspected. Moreover, anti-CD3 and anti-CD8 stains are recommended in patients not responding to the gluten-free diet (GFD) to confirm a diagnosis of Refractory Celiac Disease (RCeD). Diagnostic clues about the differential diagnosis of both CeD and RCeD have also been rendered.

Celiac disease: histology-differential diagnosis-complications. A practical approach

Celiac disease is a multi-factorial chronic inflammatory intestinal disease, characterized by malabsorption resulting from mucosal injury after ingestion of wheat gluten or related rye and barley proteins. Inappropriate T-cell-mediated immune response against ingested gluten in genetically predisposed people, leads to characteristic histological lesions, as villous atrophy and intraepithelial lymphocytosis. Nevertheless, celiac disease is a comprehensive diagnosis with clinical, serological and genetic characteristics integrated with histological features. Biopsy of duodenal mucosa remains the gold standard in the diagnosis of celiac disease with the recognition of the spectrum of histological changes and classification of mucosa damage based on updated Corazza-Villanacci system. Appropriate differential diagnosis evaluation and clinical context also for the diagnosis of complications is, moreover, needed for correct histological features interpretation and clinical management.

The Effects of Low-Dose and High-Dose Decoctions of Fructus aurantii in a Rat Model of Functional Dyspepsia

BACKGROUND Fructus aurantii is a flavonoid derived from Citrus aurantium (bitter orange) that is used in traditional Chinese medicine (TCM) to treat gastric motility disorders. This study aimed to investigate the effects of low-dose and high-dose decoctions of Fructus aurantii in a rat model of functional dyspepsia (FD). MATERIAL AND METHODS Sprague-Dawley rats (n=90) were divided into nine study groups: the control group, the FD model group, the domperidone-treated (Domp) group, the low-dose raw Fructus aurantii (FA-L) group, the high-dose raw Fructus aurantii (FA-H) group, the low-dose Fructus aurantii with stir-fried wheat bran (Bran-L) group, the high-dose Fructus aurantii with stir-fried wheat bran (Bran-H) group, the low-dose Fructus aurantii with stir-fried wheat bran and honey (Honey-L) group, and the high-dose Fructus aurantii with stir-fried wheat bran and honey (Honey-H) group. The FD rat model was established by semi-starvation, followed by tail damping, stimulation, and forced exercise with fatigue. Change in weight, rate of gastric emptying and intestinal propulsion, and serum levels of leptin, motilin, vasoactive intestinal peptide (VIP), gastrin, calcitonin gene-related peptide (CGRP), ghrelin, and cholecystokinin were compared between the groups. RESULTS In the FD model group, weight, rate of gastric emptying and intestinal propulsion significantly decreased, the expression of leptin, VIP and CGRP increased, and expression of motilin, gastrin, ghrelin, and cholecystokinin significantly decreased. Treatment with low-dose Fructus aurantii with stir-fried wheat bran significantly reversed these effects. CONCLUSIONS In the rat model of FD, low-dose Fructus aurantii with stir-fried wheat bran increased gastrointestinal motility and gastrointestinal hormone levels.

Diagnostic accuracy and applicability of intestinal auto-antibodies in the wide clinical spectrum of coeliac disease

BACKGROUND

Intestinal coeliac auto-antibodies are the marker of coeliac disease (CD). Since the determination of these antibodies is still not widely available, we used immunoassays to identify the most suitable technology for revealing intestinal auto-antibodies in the wide clinical spectrum of CD.

METHODS

Intestinal auto-antibodies have been prospectively investigated in CD suspected children using two immunoassays: intestinal-deposits of IgA anti-tissue transglutaminase antibodies (anti-tTG) and biopsy-culture IgA anti-endomysium (AEA). Intestinal IgM antibodies have been determined in IgA-deficient subjects.

FINDINGS

Two-hundred and twenty-one suspected CD patients were enrolled. Intestinal antibodies were tested positive for both assays in classical CD patients (n = 178) with villous atrophy and positive serum-CD antibodies, potential CD patients (n = 16) with normal intestinal mucosa and positive serum-CD antibodies, and pre-potential CD patients (n = 14) with normal intestinal mucosa and negative serum-CD antibodies. In 13/221 with normal intestinal mucosa, negative CD-serum antibodies and negative intestinal antibodies CD has been excluded. All classical, 14/16 potential and 11/14 pre-potential CD patients on gluten-free diet (GFD) improved their symptoms. In 9/11 pre-potential patients intestinal antibodies disappeared on GFD. Both assays were negative in 69/71 control subjects. The two assays showed high diagnostic sensitivity (100%) and specificity (99%).

INTERPRETATION

Intestinal CD-antibodies make prompt diagnosis in the wide clinical spectrum of CD reducing the delay in diagnosis and treatment, especially in pre-potential CD patients. The easy handling biopsy culture assay is an effective diagnostic tool which should be carried out by any gastroenterology unit to recognize all CD clinical manifestations.

FUNDING

Interreg Central-Europe, IRCCS "Burlo Garofolo".

The Challenge of Treatment in Potential Celiac Disease

Potential celiac disease (PCD) is defined by the presence of positive serum antibodies, HLA-DQ2/DQ8 haplotypes, and a normal small intestinal mucosa (Marsh grade 0-1). This condition occurs in one-fifth of celiac disease (CD) patients and usually represents a clinical challenge. We reviewed genetic, histologic, and clinical features of this specific condition by performing a systematic search on MEDLINE, Embase, and Scholar database. Accordingly, we identified different genetic features in patients with PCD compared to the classical forms. Frequently, signs of inflammation (deposits of immunoglobulin A (IgA) and/or increased number of intraepithelial lymphocytes) can be clearly identify in the mucosa of PCD patients after an accurate histological assessment. Finally, the main challenge is represented by the treatment: the gluten-free diet should be considered only in the presence of gluten-dependent symptoms in both children and adults. What is known: (i) potential celiac disease (PCD) occurs in one-fifth of all celiac diseases (CD), and (ii) despite the absence of classical lesions, clear signs of inflammation are often detectable. What is new: (i) patients with PCD show different genetic features, and (ii) the presence of gluten-dependent symptoms is the main determinant to initiate the gluten-free diet, after a complete diagnostic work-up.

Common Problems Found in the Methodological Approach to Small Bowel Biopsies in the Diagnosis of Celiac Disease

Small bowel biopsy (SBB) is not always helpful to establish celiac disease diagnosis. Hence we have conducted a retrospective study to know the amount of SBB in our center that was not optimal for this purpose. Histological findings were not appropriate for diagnosis in 3.56% (34 out of 955). The main problem encountered was inadequate sample cutting, although this could be solved by a new recut in almost 30% of cases.