Increase in gamma/delta T cell receptor bearing lymphocytes in normal small bowel mucosa in latent coeliac disease

Intraepithelial Lymphogram in the Diagnosis of Celiac Disease in Adult Patients: A Validation Cohort

BACKGROUND

Celiac disease is a gluten-related pathology, highly prevalent and heterogeneous in its clinical presentation, which leads to delays in diagnosis and misdiagnosis. The analysis of duodenal intraepithelial lymphocytes (IELs) by flow cytometry (lymphogram) is emerging as a discriminative tool in the diagnosis of various forms of celiac disease (CD).

AIMS

The aim of this study was to validate IEL lymphogram performance in the largest adult series to our knowledge, in support of its use as a diagnostic tool and as a biomarker of the dynamic celiac process.

METHODS

This was a retrospective study including 768 adult patients (217 with active CD, 195 on a gluten-free diet, 15 potential CD patients, and 411 non-celiac controls). The IEL subset cut-off values were established to calculate the diagnostic accuracy of the lymphogram.

RESULTS

A complete celiac lymphogram profile (≥14% increase in T cell receptor [TCR]γδ IELs and simultaneous ≤4% decrease in surface-negative CD3 [sCD3-] IELs) was strongly associated with active and potential forms in over 80% of the confirmed patients with CD, whereas the remaining patients with CD had partial lymphogram profiles (≥14% increase in TCRγδ or ≤4% decrease in sCD3- IELs), with lower diagnostic certainty. None of these patients had a non-celiac lymphogram. Quantifying the TCRγδ versus sCD3- imbalance as a ratio (≥5) is a discriminative index to discard or suspect CD at diagnosis.

CONCLUSIONS

We have validated the IEL lymphogram's diagnostic efficiency (79% sensitivity, 98% specificity), with an LR+ accuracy of 36.2. As expected, the increase in TCRγδ IELs is a reliable marker for celiac enteropathy, while changes in sCD3- IEL levels throughout the dynamic CD process are useful biomarkers of mucosal lesions.

CT and MR Enterography in the Evaluation of Celiac Disease

Celiac disease is a common inflammatory disease of the small bowel that induces mucosal intestinal lesions. The disease is mediated by an immune response and triggered by the ingestion of gluten in genetically predisposed individuals. Gluten contains gliadin, a component found mostly in wheat, barley, and rye. This process leads to gastrointestinal malabsorption with symptoms such as diarrhea, constipation, abdominal pain, and distention. It has a prevalence of 1%-2% in the general adult population, who present with symptoms at any age, but is more frequently found in adult women in the 3rd or 4th decade of life. Recognition of the disease has increased, but it remains a challenge to diagnose. CT and MR enterography are noninvasive studies used for evaluation of small bowel neoplasms and inflammatory small bowel pathologic conditions such as celiac disease. The authors review the spectrum of intestinal and extraintestinal findings of celiac disease at CT and MR enterography, as well as its complications, and the importance of recognizing certain imaging features that help in the diagnosis of celiac disease. More common and specific findings of celiac disease such as inversion of the jejunoileal fold pattern and mesenteric lymphadenopathy are reviewed. More uncommon entities that are more frequently associated with refractory or untreated celiac disease, such as ulcerative jejunoileitis, cavitary mesenteric lymph node syndrome, and malignancies including small bowel adenocarcinoma and lymphoma, are described. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. The slide presentation from the RSNA Annual Meeting is available for this article.

Characterisation of T cell receptor repertoires in coeliac disease

AIMS

Characterise T-cell receptor gene (TR) repertoires of small intestinal T cells of patients with newly diagnosed (active) coeliac disease (ACD), refractory CD type I (RCD I) and patients with CD on a gluten-free diet (GFD).

METHODS

Next-generation sequencing of complementarity-determining region 3 (CDR3) of rearranged T cell receptor β (TRB) and γ (TRG) genes was performed using DNA extracted from intraepithelial cell (IEC) and lamina propria cell (LPC) fractions and a small subset of peripheral blood mononuclear cell (PBMC) samples obtained from CD and non-CD (control) patients. Several parameters were assessed, including relative abundance and enrichment.

RESULTS

TRB and TRG repertoires of CD IEC and LPC samples demonstrated lower clonality but higher frequency of rearranged TRs compared with controls. No CD-related differences were detected in the limited number of PBMC samples. Previously published LP gliadin-specific TRB sequences were more frequently detected in LPC samples from patients with CD compared with non-CD controls. TRG repertoires of IECs from both ACD and GFD patients demonstrated increased abundance of certain CDR3 amino acid (AA) motifs compared with controls, which were encoded by multiple nucleotide variants, including one motif that was enriched in duodenal IECs versus the PBMCs of CD patients.

CONCLUSIONS

Small intestinal TRB and TRG repertoires of patients with CD are more diverse than individuals without CD, likely due to mucosal recruitment and accumulation of T cells because of protracted inflammation. Enrichment of the unique TRG CDR3 AA sequence in the mucosa of patients with CD may suggest disease-associated changes in the TCRγδ IE lymphocyte (IEL) landscape.

Intestinal and blood lymphograms as new diagnostic tests for celiac disease

Accurate celiac disease (CD) diagnosis is still challenging for some specific patients or circumstances. Thus, much effort has been expended last decades focused on seronegative or low grade enteropathy CD and, especially, on enable early diagnosis of individuals on a gluten-free diet (GFD). We discuss here two diagnostic approaches based on immunophenotyping by flow cytometry that we expect to reduce the persistent low diagnostic rates and the common diagnostic delay. The intraepithelial lymphogram is based on determining the percentage of TCRγδ+ and surface CD3- lymphocytes in the intestinal epithelium. The concomitant increase in TCRγδ+ and decrease in surface CD3- intraepithelial lymphocytes has been termed the celiac lymphogram and has been proved to be discriminative in seronegative, low grade enteropathy and potential CD, as well as in most CD patients on a GFD. A blood lymphogram based on the analysis of activated gut-homing CD8+ T cells combined with a 3-day gluten challenge is also considered, which has shown high sensitivity and specificity to diagnose seropositive Marsh 1 and Marsh 3 CD in individuals following a GFD. In addition, flow cytometry can be extremely useful in cases of refractory CD type II to identify aberrant cells. Those approaches represent highly accurate methods for CD diagnosis, being simple, fast, highly reproducible and of easy implementation in clinical practice.

Assessment of Duodenal Intraepithelial Lymphocyte Composition (Lymphogram) for Accurate and Prompt Diagnosis of Celiac Disease in Pediatric Patients

INTRODUCTION

Quantitative and phenotypic analyses of duodenal intraepithelial lymphocytes (IELs) by flow cytometry (IEL lymphogram) confer specificity and enable the diagnosis even in unconventional presentations of celiac disease (CD). To evaluate the validity of the IEL lymphograms in the pediatric population for new insights into their use as biomarkers in the natural history of CD.

METHODS

We retrospectively included 1,211 children (602 with active CD, 92 on a gluten-free diet, 47 with potential CD, and 470 nonceliac controls) who required duodenal biopsies in this study. The cutoff values for IEL subsets were established to calculate the probability of disease according to the lymphogram.

RESULTS

A celiac lymphogram (a ≥15% increase in gamma-delta T-cell receptor IELs and a simultaneous ≤6% decrease in CD3 surface-negative [sCD3-]) IELs was strongly associated with the diagnosis of active CD, which was present in 89.7% of the confirmed patients. The remaining 10% of the celiac patients had a partial celiac lymphogram (≥15% increase gamma-delta T-cell receptor IELs or ≤6% decrease in sCD3- IELs), with lower diagnostic certainty. On a gluten-free diet, nearly 20% of the patients were indistinguishable from nonceliac subjects based on the lymphogram. In potential CD, a decrease in sCD3- IELs was a risk marker of progression to villous atrophy and a diagnosis of active CD.

DISCUSSION

If a biopsy is clinically indicated, the IEL lymphogram adds specificity to the histological findings, reducing diagnostic delays and misdiagnoses. The lymphogram is useful for monitoring the natural progression of the disease and predicting the transition from potential celiac to overt CD.

Long-Term Effect of a Gluten-Free Diet on Diarrhoea- or Bloating-Predominant Functional Bowel Disease: Role of the 'Low-Grade Coeliac Score' and the 'Coeliac Lymphogram' in the Response Rate to the Diet

1.

BACKGROUND

The long-term effect of a gluten-free diet (GFD) on functional bowel disorders (FBDs) has been scarcely studied. The aim was to assess the effect of a GFD on FBD patients, and to assess the role of both the low-grade coeliac score and coeliac lymphogram in the probability of response to a GFD. 2.

METHODS

116 adult patients with either predominant diarrhoea or abdominal bloating, fulfilling Rome IV criteria of FBD, were treated with a GFD. Duodenum biopsies were performed for both pathology studies and intraepithelial lymphocyte subpopulation patterns. Coeliac lymphogram was defined as an increase in TCRγδ+ cells plus a decrease in CD3- cells. A low-grade coeliac score >10 was considered positive. 3.

RESULTS

Sustained response to GFD was observed in 72 patients (62%) after a median of 21 months of follow-up, who presented more often with coeliac lymphogram (37.5 vs. 11.4%; p = 0.02) and a score >10 (32 vs. 11.4%; p = 0.027) compared to non-responders. The frequency of low-grade coeliac enteropathy was 19.8%. 4.

CONCLUSION

A GFD is effective in the long-term treatment of patients with previously unexplained chronic watery diarrhoea- or bloating-predominant symptoms fulfilling the criteria of FBD. The response rate was much higher in the subgroup of patients defined by the presence of both a positive low-grade coeliac score and coeliac lymphogram.

Histological, immunohistochemical and mRNA gene expression responses in coeliac disease patients challenged with gluten using PAXgene fixed paraffin-embedded duodenal biopsies

Background

There is an unmet need for novel treatments, such as drugs or vaccines, adjunctive to or replacing a burdensome life-long gluten-free diet for coeliac disease. The gold standard for successful treatment is a healed small intestinal mucosa, and therefore, the outcome measures in proof-of-concept studies should be based on evaluation of small intestine biopsies. We here evaluated morphometric, immunohistochemical and messenger RNA (mRNA) expression changes in coeliac disease patients challenged with gluten using PAXgene fixed paraffin-embedded biopsies.

Methods

Fifteen coeliac disease patients were challenged with 4 g of gluten per day for 10 weeks and 24 non-coeliac patients served as disease controls. A wide array of histological and immunohistochemical staining and mRNA-based gene expression tests (RT-qPCR and RNAseq) were carried out.

Results

Digital quantitative villous height: crypt depth ratio (VH: CrD) measurements revealed significant duodenal mucosal deterioration in all coeliac disease patients on gluten challenge. In contrast, the Marsh-Oberhuber class worsened in only 80% of coeliac patients. Measuring the intraepithelial CD3⁺ T-lymphocyte and lamina propria CD138⁺ plasma cell densities simultaneously proved to be a meaningful new measure of inflammation. Stainings for γδ T cells and IgA deposits, where previously frozen samples have been needed, were successful in PAXgene fixed paraffin-embedded samples. Messenger RNA extraction from the same paraffin-embedded biopsy block was successful and allowed large-scale qRT-PCR and RNAseq analyses for gene expression. Molecular morphometry, using the mRNA expression ratio of villous epithelium-specific gene APOA4 to crypt proliferation gene Ki67, showed a similar significant distinction between paired baseline and post-gluten challenge biopsies as quantitative histomorphometry.

Conclusion

Rigorous digitally measured histologic and molecular markers suitable for gluten challenge studies can be obtained from a single paraffin-embedded biopsy specimen. Molecular morphometry seems to be a promising new tool that can be used in situations where assessing duodenal mucosal health is of paramount importance. In addition, the diagnostically valuable IgA deposits were now stained in paraffin-embedded specimens making them more accessible in routine clinics.

A Scoring System for Identifying Patients Likely to Be Diagnosed with Low-Grade Coeliac Enteropathy

BACKGROUND & AIMS

Determining whether patients with lymphocytic enteritis (LE) have coeliac disease is a challenge. We analysed the variables associated with a low-grade coeliac enteropathy diagnosis in patients with suspected coeliac disease but without villous atrophy, and developed a scoring system to identify them.

METHODS

We collected data from 2010 through to 2016 on patients with lymphocytic enteritis and persistent symptoms compatible with the clinical spectrum of coeliac disease. One hundred and four patients starting on a gluten-free diet (GFD) were included. Duodenal biopsies were collected before the GFD and analysed for numbers of CD3⁺ T-cell receptor gamma delta+ (TCRγδ⁺), and CD3^- intraepithelial lymphocytes. We performed a logistic regression analysis to identify factors associated with a low-grade coeliac enteropathy diagnosis.

RESULTS

Sixty-two patients achieved clinical remission after the GFD. Fifty of these 62 patients were diagnosed with low-grade coeliac enteropathy. Multivariate analysis identified the presence of >25% intraepithelial lymphocytosis, HLA-DQ2.5, positive serology, and increased numbers of TCRγδ⁺ cells with a low-grade coeliac enteropathy diagnosis. We developed a scoring system that identified patients with an area under the ROC curve (AUC) of 0.91. Scores of >10 had 86% sensitivity and 85% specificity.

CONCLUSION

We developed a scoring system that identifies patients likely to be diagnosed with low-grade coeliac enteropathy with an AUC value of 0.91.

Gamma-Delta T Lymphocytes in the Diagnostic Approach of Coeliac Disease

GOALS

To validate cut-off values of CD3 T-cell receptor gamma-delta chain (TCRγδ) intraepithelial lymphocyte (IEL) in the (differential) diagnosis of celiac disease (CD).

BACKGROUND

CD is characterized by an increase in gamma-delta IEL (CD3TCRγδ IEL).

STUDY

Percentages were determined by flow cytometric analysis of IELs from small bowel biopsies in 213 CD and 13 potential CD (PCD) patients and in total 112 controls. A cut-off value for percentages of CD3TCRγδ IEL to differentiate active CD and controls was obtained from a receiver operating characteristic curve and implemented in controls and PCD patients.

RESULTS

Percentage of CD3TCRγδ IEL was significantly increased in the majority of CD patients, irrespective of the presence of villous atrophy. A cut-off value of 14% for CD3TCRγδ IEL resulted in 66.3% sensitivity and 96.6% specificity for CD diagnosis (area under the curve, 88.6%).

CONCLUSIONS

A percentage of ≥14% CD3TCRγδ IEL has a high specificity for CD diagnosis and can be of diagnostic help in cases where diagnosis is not straightforward.

Gluten-Induced Extra-Intestinal Manifestations in Potential Celiac Disease-Celiac Trait

Celiac disease patients may suffer from a number of extra-intestinal diseases related to long-term gluten ingestion. The diagnosis of celiac disease is based on the presence of a manifest small intestinal mucosal lesion. Individuals with a normal biopsy but an increased risk of developing celiac disease are referred to as potential celiac disease patients. However, these patients are not treated. This review highlights that patients with normal biopsies may suffer from the same extra-intestinal gluten-induced complications before the disease manifests at the intestinal level. We discuss diagnostic markers revealing true potential celiac disease. The evidence-based medical literature shows that these potential patients, who are “excluded” for celiac disease would in fact benefit from gluten-free diets. The question is why wait for an end-stage disease to occur when it can be prevented? We utilize research on dermatitis herpetiformis, which is a model disease in which a gluten-induced entity erupts in the skin irrespective of the state of the small intestinal mucosal morphology. Furthermore, gluten ataxia can be categorized as its own entity. The other extra-intestinal manifestations occurring in celiac disease are also found at the latent disease stage. Consequently, patients with celiac traits should be identified and treated.

Abnormalities in CD57+ cytotoxic T cells and Vδ1+ γδT cells in subclinical celiac disease in childhood are affected by cytomegalovirus. The Generation R Study

Celiac disease (CD) is a digestive and autoimmune disorder driven by an immune response to modified gluten peptides. Affected intestines show infiltrates of various T-cell and NK-cell subsets. It is currently unclear if individuals with subclinical CD have systemic abnormalities in immune cells. We here studied whether subclinical CD is associated with changes in blood CD57-expressing and Vδ1-expressing lymphocytes in children, and whether cytomegalovirus (CMV) infection modifies this association. Included were 1068 children from the Generation R Study. Serum Immunoglobulin G (IgG) levels against CMV were measured by ELISA; Tissue transglutaminase type 2 antibody (TG2A) levels with fluorescence enzyme immunoassay (FEIA). Duodenal biopsies, additional Human Leukocyte Antigen (HLA) DQ 2.2, 2.5 and 8 and endomysial antibody (EMA) typing were performed in TG2A positive children. Subclinical CD cases (n=12) had 1.8 fold (95% CI 1.06; 3.1) fewer Vδ1+ T cells which was predominantly observed in CMV seronegative children (p-interaction 0.02), and 2.7 fold (95% CI 1.25; 5.99) more CD57+ T cells than HLA DQ2/-DQ8 positive controls (n=339). Hence, children with subclinical CD have alterations in specific blood T cell subsets that are linked to viral pathology. The observed interaction effect between subclinical CD and CMV may contribute to the understanding of disease pathogenesis.

Intraepithelial lymphocytes subsets in different forms of celiac disease

AIM

The enumeration of intraepithelial lymphocytes subsets (total, γδ, and CD3(-) IELs) by flow cytometry (FCM), named as IEL lymphogram, constitutes a useful tool for celiac disease (CD) diagnosis. The aim of this study was to quantify IELs by FCM and their diagnostic value to differentiate active, silent and potential CD.

METHODS

Prospective study of 60 active and 20 silent CD patients, and 161 controls in which duodenal biopsy and IEL quantification by FCM was performed.

RESULTS

Active and silent CD patients had significant higher levels of both total and γδ IELs than absent CD patients (P < 0.0001 and P < 0.0001, P = 0.012 and P < 0.011; respectively). Active and silent CD patients had significant lower levels of CD3(-) IELs than absent CD patients (P < 0.047 and P < 0.009, respectively). Moreover, they were lower in silent than in active CD patients (P = 0.002). Changes of IELs subsets were more marked in children than adults active CD. The optimal IEL lymphogram cut off values for active CD diagnosis were: ≥10, ≥15 and ≤9 %, and with better performance characteristics for silent CD: ≥ 11, ≥10 and ≤5 %.

CONCLUSION

The evaluation of IELs subsets by FCM is useful to confirm diagnosis of active and silent CD.

An Attempt of Specific Desensitising Treatment with Gliadin in Celiac Disease

Gluten-free diet is the current treatment of celiac disease. We decided to verify the occurrence of histological and serological modification and/or clinical manifestations during a gradual and progressive introduction of gliadin in the diet and if it may induce a tolerance to food, as it occurs in allergic patients. We studied the case of a celiac woman with complete clinical and histological remittance after 10 years of gluten free diet. She took increasing daily doses of gliadin, reaching the final dose of 9 g of gliadin (15 g of gluten) in 6 months. Then she started a free dietary regimen. During the 15-month follow-up period esophago-gastro-duodenoscopy showed normal Kerckring folds and villi. Anti-gliadin, anti-endomysium and anti-tissue-transglutaminase antibodies, as well as the haematological and biochemical parameters remained normal. Our results represent a new approach in the research concerning celiac disease, and could provide a future line of study for its management.

A Prospective Study on the Usefulness of Duodenal Bulb Biopsies in Celiac Disease Diagnosis in Children: Urging Caution

OBJECTIVES

Several recent celiac disease guidelines recommend the acquisition of duodenal bulb biopsies for diagnostics. This is in conflict with previously reported evidence and routine practice from the 1960s onward. We reopened the issue in a prospective multicenter study and used morphometric variables in evaluating the usefulness of bulb biopsies in children. We further sought to establish whether deposits of IgA targeting bulb transglutaminase 2 (TG2) could be of diagnostic help.

METHODS

Diagnoses of celiac disease were based on clinic and distal duodenal histopathology statements. Centralized reading of villous height (VH) to crypt depth (CrD) ratios and IgA deposits was performed on anatomical duodenal bulb specimens. All children participating also underwent routine investigations for other diseases.

RESULTS

Twenty-two children had celiac disease, and another 22 served as non-celiac disease controls. The quality of the anatomical bulb specimens was unsatisfactory for reliable morphometric measurements in 20 out of 44 (45%) patients even after recuttings. All celiac disease patients had VH:CrD<2.0 (mean 0.2) but also 10 out of 13 (77%) non-celiac control patients had an injured bulb mucosal lining (mean 1.3) even up to false-positive "flat lesion". Bulb IgA deposits were able to separate celiac disease from disease controls.

CONCLUSIONS

Morphological injury is common in the anatomical bulb even without celiac disease, increasing the risk of false-positive diagnoses. Premature conclusions might have been drawn on current care guidelines as to celiac disease diagnosis based solely on anatomical bulb specimens. Bulb mucosal IgA targeting TG2 in poor quality biopsy specimens is a powerful clinical tool in finding celiac disease patients.

Discriminant score for celiac disease based on immunohistochemical analysis of duodenal biopsies

OBJECTIVES

Celiac disease (CD) represents a spectrum, which includes cases with minor histological abnormalities (potential CD). The aim of this work is to evaluate the contribution of immunohistochemical analysis of duodenal biopsies to the diagnosis of gluten-related minor enteropathy.

METHODS

Duodenal biopsies from 56 patients with untreated CD and 56 controls were analyzed for CD3 and γδ intraepithelial lymphocyte number, γδ/CD3 ratio, and density of CD25+ lamina propria cells. A discriminant equation was obtained by which 61 more biopsies with normal villous architecture were blindly evaluated.

RESULTS

All of the immunohistochemical parameters were significantly different between patients with CD and controls. None of the single parameters showed sufficient specificity for CD. The combination of all of the 4 markers resulted in the following discriminant equation: discriminant score (Dscore) = (CD3 × 0.06) - (γδ × 0.119) + (CD25 × 0.012) + (γδ/CD3 × 0.131) - 4.709. Using this Dscore, patients were correctly classified as celiac or controls in 97.3% of the cases. When this equation was applied to a validation set of 61 patients with normal villous architecture and unknown diagnosis, 92.9% of those with a positive score turned out to be patients with potential CD. A normal score, however, did not exclude this condition.

CONCLUSIONS

Immunohistochemistry represents a specific tool for the diagnosis of CD, but does lack sensitivity in detecting all of the potential CD cases.

Phenotypical characterization of the peripheral blood T cells in patients with celiac disease: does it differentiate suspicious celiac disease cases?

AIM

The present study aimed to study the immunological changes seen in the intestinal epithelium of the celiac patients could also be detected in the peripheral blood lymphocyte populations.

BACKGROUND

Celiac disease (CD) is a small bowel enteropathy caused by permanent wheat gluten intolerance. One of the earliest signs of CD is an increase in the numbers of the intestinal intraepithelial lymphocytes (iIEL).

PATIENTS AND METHODS

In this case-control study, totally 13 untreated subjects with acceptable criteria for CD without any complication and 16 healthy subjects without any positive criteria for CD were selected. Peripheral blood T cells were analyzed by two-color flow cytometry in both groups.

RESULTS

The mean age of patients was 33.6 ± 3.4 years and two patients had Marsh IIIB, five patients had Marsh IIIA and six patients had Marsh II histology class. The mean percentages of the TCR(+) T cells in the patients were significantly higher than the controls (p=0.015). However, the mean percentages of the αβTCR(+) T cells were significantly lower in the untreated patients than the controls (p=0.025). There were no significant difference between the mean percentages of lymphocytes expressing the CD3, CD4 and CD8 molecules in the patients and the controls.

CONCLUSION

The change in the percentages of the peripheral blood T cells expressing the γδTCR and αβTCR in the celiac patients could be used in conjunction with the other serological markers to identify new CD cases.

Intestinal intraepithelial lymphocyte cytometric pattern is more accurate than subepithelial deposits of anti-tissue transglutaminase IgA for the diagnosis of celiac disease in lymphocytic enteritis

BACKGROUND & AIMS

An increase in CD3+TCRγδ+ and a decrease in CD3- intraepithelial lymphocytes (IEL) is a characteristic flow cytometric pattern of celiac disease (CD) with atrophy. The aim was to evaluate the usefulness of both CD IEL cytometric pattern and anti-TG2 IgA subepithelial deposit analysis (CD IF pattern) for diagnosing lymphocytic enteritis due to CD.

METHODS

Two-hundred and five patients (144 females) who underwent duodenal biopsy for clinical suspicion of CD and positive celiac genetics were prospectively included. Fifty had villous atrophy, 70 lymphocytic enteritis, and 85 normal histology. Eight patients with non-celiac atrophy and 15 with lymphocytic enteritis secondary to Helicobacter pylori acted as control group. Duodenal biopsies were obtained to assess both CD IEL flow cytometric (complete or incomplete) and IF patterns.

RESULTS

Sensitivity of IF, and complete and incomplete cytometric patterns for CD diagnosis in patients with positive serology (Marsh 1+3) was 92%, 85 and 97% respectively, but only the complete cytometric pattern had 100% specificity. Twelve seropositive and 8 seronegative Marsh 1 patients had a CD diagnosis at inclusion or after gluten free-diet, respectively. CD cytometric pattern showed a better diagnostic performance than both IF pattern and serology for CD diagnosis in lymphocytic enteritis at baseline (95% vs 60% vs 60%, p = 0.039).

CONCLUSIONS

Analysis of the IEL flow cytometric pattern is a fast, accurate method for identifying CD in the initial diagnostic biopsy of patients presenting with lymphocytic enteritis, even in seronegative patients, and seems to be better than anti-TG2 intestinal deposits.

Immunohistochemical and T-cell receptor gene rearrangement analyses as predictors of morbidity and mortality in refractory celiac disease

BACKGROUND

Classification of refractory celiac disease (RCD) is based on the presence or absence of monoclonal expansions of intraepithelial lymphocytes (IELs) with an aberrant immunophenotype.

GOALS

To investigate the contribution of IEL parameters toward mortality and morbidity in RCD.

STUDY

IEL phenotype by immunohistochemistry and T-cell receptor (TCR) gene rearrangement by polymerase chain reaction were assessed in 73 RCD patients (type I=67, type II=6). Detection of a monoclonal TCR gene rearrangement and presence of <50% CD3 CD8 IELs were considered abnormal. Time to worsening of clinical symptoms and predictors of worsening were calculated by Kaplan-Meier and Cox proportional hazard analyses.

RESULTS

Fewer than 50% CD3 CD8 IELs were detected in 30 patients and monoclonal TCR rearrangements in 6. Three patients died and 40 suffered clinical worsening despite treatment. Estimated 5-year survival rates decreased from 100% in patients with >50% CD3 CD8 IELs and polyclonal TCR to 88% and 50% in patients with <50% CD3 CD8 IELs and monoclonal TCR, respectively. Clinical worsening was more frequent (100%) among patients harboring a monoclonal TCR gene rearrangement with <50% CD3 CD8 IELs. These patients also showed shorter median time to clinical worsening (11 mo) when compared to patients with <50% CD3 CD8 IELs alone (21 mo), polyclonal TCR (38 mo), or >50% CD3 CD8 IELs alone (66 mo). After adjusting for age and gender, only the presence of <50% CD3 CD8 IELs was associated with increased risk for clinical worsening despite negative celiac serologies (hazard ratio=4.879; 95% confidence interval, 1.785-13.336; P=0.002).

CONCLUSIONS

Presence of <50% CD3 CD8 IELs is a risk factor for clinical worsening in RCD and combined with a monoclonal TCR gene rearrangement result is associated with increased mortality. IEL phenotype and TCR gene rearrangement analyses provide differential information regarding morbidity and mortality in RCD.

Anti-TCR gamma antibody in celiac disease: the value of count on formalin-fixed paraffin-embedded biopsies

Small bowel intraepithelial lymphocytosis (IL) may depend from different causes, including celiac disease (CD). Demonstration of increased number of duodenal T cell receptor gamma-delta (TCRγδ) positive intraepithelial lymphocytes (IELs) has been used to support CD diagnosis on frozen material. This work evaluates a new commercially available anti-TCRγ antibody on formalin-fixed paraffin embedded (FFPE) small bowel biopsies. Anti-CD3 and anti-TCR CγM1 (clone γ3.20) from Thermo Scientific were applied by immunohistochemistry on 59 FFPE biopsies from 18 cases of CD with mild/severe atrophy, 19 cases of IL in CD patients on gluten-free diet (IL-GFD), 14 cases of IL (6/14 with positive CD-related serology), and 8 controls (CTR) with mild duodenitis and negative CD serology and genotyping. IELs/100 epithelial cells were counted in at least six high power fields. CD3+ and TCRγ+ IELs were significantly higher in CD, IL-GFD, and IL compared with CTR, but in contrast to CD3+ IELs, TCRγ+ IELs were significantly increased in CD and IL-GFD compared with IL. Furthermore, TCRγ+ IELs discriminated between IL with negative and positive CD-related serology (p = 0.02). TCRγ+ IELs can be identified on FFPE samples and their evaluation adds useful information for the work-up of small bowel biopsies in CD diagnosis. In fact, TCRγ staining coupled with CD3, may represent an additional tool to recognize cases of latent/potential CD when serology and clinical data are not conclusive or when the histological diagnosis remains equivocal.

Human leukocyte antigen genetics and clinical features of self-treated patients on a gluten-free diet

BACKGROUND AND AIMS

Increasingly, people start a gluten-free diet (GFD) without a clear celiac disease (CD) diagnosis. Human leukocyte antigen (HLA) genotyping is useful in ruling out CD in patients with equivocal results of serologic testing or small-bowel biopsy (SBB), but its utility and the clinical features of patients on self-treated GFD (ST-GFD) are largely unknown.

METHODS

Retrospective study of single tertiary care center cohort compared 137 patients on ST-GFD and 443 patients with well-defined CD. We compared HLA genotype, symptoms, serologic and SBB results, and response to GFD between the 2 groups. Analysis used univariate logistic regression modeling, adjusted for age and sex.

RESULTS

Patients with ST-GFD presented more often with diarrhea (P<0.001), abdominal distention (P<0.001), flatulence (P=0.002), cramping (P=0.02), itchy skin (P=0.02), oral inflammation (P=0.04), and constipation (P=0.01) and less often with anemia (P<0.001) or malaise (P=0.02) than CD patients. In addition, 41% did not carry DQ2.5 and DQ8 versus 6% of CD patients (P<0.001). Only 2% of ST-GFD patients had SBB clearly consistent with CD. Family history of CD showed no difference between groups (P=0.77). Although CD patients had a statistically higher rate of GFD benefit, both groups had a high responsiveness rate (98% vs. 94%; P=0.03).

CONCLUSIONS

HLA genotyping is useful in evaluating patients on an ST-GFD. Although confirmed CD is rare in self-treated patients, most still report benefit from GFD regardless of DQ2 and DQ8 status. Nonceliac gluten sensitivity may play a role.

The Oslo definitions for coeliac disease and related terms

OBJECTIVE

The literature suggests a lack of consensus on the use of terms related to coeliac disease (CD) and gluten.

DESIGN

A multidisciplinary task force of 16 physicians from seven countries used the electronic database PubMed to review the literature for CD-related terms up to January 2011. Teams of physicians then suggested a definition for each term, followed by feedback of these definitions through a web survey on definitions, discussions during a meeting in Oslo and phone conferences. In addition to 'CD', the following descriptors of CD were evaluated (in alphabetical order): asymptomatic, atypical, classical, latent, non-classical, overt, paediatric classical, potential, refractory, silent, subclinical, symptomatic, typical, CD serology, CD autoimmunity, genetically at risk of CD, dermatitis herpetiformis, gluten, gluten ataxia, gluten intolerance, gluten sensitivity and gliadin-specific antibodies.

RESULTS

CD was defined as 'a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically predisposed individuals'. Classical CD was defined as 'CD presenting with signs and symptoms of malabsorption. Diarrhoea, steatorrhoea, weight loss or growth failure is required.' 'Gluten-related disorders' is the suggested umbrella term for all diseases triggered by gluten and the term gluten intolerance should not to be used. Other definitions are presented in the paper.

CONCLUSION

This paper presents the Oslo definitions for CD-related terms.

Histopathology of celiac disease

Small bowel biopsy remains the gold standard for diagnosing celiac disease (CD). Intraepithelial lymphocytosis in the context of villous atrophy is considered a characteristic histologic finding of CD. However, studies have also indicated that the detection of intraepithelial lymphocytosis in the absence of villous atrophy is not specific for CD, having been documented in other small intestinal disorders. This review summarizes key aspects regarding the histopathologic assessment, impact of the site and number of small bowel biopsy samples on diagnosis, old and emerging classifications, and benefit of standardized pathology report in the diagnostic workup of CD.

An update on celiac disease histopathology and the road ahead

CONTEXT

Celiac disease (CD) is a common immune-mediated disorder that occurs in genetically predisposed individuals (carriers of HLA-DQ2 and DQ8 haplotypes) on consumption of wheat (gluten). It is characterized by inflammation of the small-intestinal mucosa and myriad gastrointestinal and systemic manifestations. Celiac disease is common in the general population (prevalence, 0.5%-1%). Currently, small-bowel biopsy is considered the gold standard for diagnosing CD. However, the role of serologic testing in the diagnosis of CD has evolved, from being a supportive test to supplanting intestinal biopsies in certain patient populations.

OBJECTIVE

To summarize key aspects of histopathologic assessment, discuss the benefit of standardized pathology reports, impact of the site and number of small-bowel biopsy samples on diagnosis, and recommendations regarding serologic testing.

DATA SOURCES

Literature review of publications on CD and experience with histopathologic review of biopsies at the Department of Pathology and Cell Biology, Columbia University Medical Center, New York-Presbyterian Hospital, New York.

CONCLUSIONS

Intraepithelial lymphocytosis in the context of villous atrophy is considered a characteristic histologic finding of CD; however, it is a rather nonspecific finding. A growing list of publications has also indicated that the detection of intraepithelial lymphocytosis in the absence of villous atrophy has rather low specificity for CD. Therefore, communication between pathologists and gastroenterologists is paramount, as is knowledge regarding the pertinent clinical and laboratory data, in distinguishing between CD and other disorders with similar histopathologic and clinical manifestations.

Intraepithelial lymphocytes in celiac disease immunopathology

Celiac disease is a T cell-mediated immune disorder induced by dietary gluten that is characterized by the development of an inflammatory anti-gluten CD4 T cell response, anti-gluten antibodies, and autoantibodies against tissue transglutaminase 2 and the activation of intraepithelial lymphocytes (IELs) leading to the destruction of the intestinal epithelium. Intraepithelial lymphocytes represent a heterogeneous population of T cells composed mainly of cytotoxic CD8 T cells residing within the epithelial layer, whose main role is to maintain the integrity of the epithelium by eliminating infected cells and promoting epithelial repair. Dysregulated activation of IELs is a hallmark of CD and is critically involved in epithelial cell destruction and the subsequent development of villous atrophy. In this review, we compare and contrast the phenotype and function of human and mouse small intestinal IELs under physiological conditions. Furthermore, we discuss how conditions of epithelial distress associated with overexpression of IL-15 and non-classical MHC class I molecules induce cytotoxic IELs to become licensed killer cells that upregulate activating NKG2D and CD94/NKG2C natural killer receptors, acquiring lymphokine killer activity. Pathways leading to dysregulated IEL activation could eventually be targeted to prevent villous atrophy and treat patients who respond poorly to gluten-free diet.

Celiac disease in children and adolescents: special considerations

Although there are many commonalities between adult and pediatric celiac disease (CD), special considerations must be taken into account when working with children and adolescents. In this patient population, there are unique aspects of the epidemiology, pathogenesis, presentation, diagnosis, and management of CD. In terms of management, early and timely recognition of CD can maximize childhood and adolescent development and prevent complications. This requires insight into the unique presentations of CD in the pediatric population. Furthermore, health care providers must use proper screening methods and continue surveillance of at-risk individuals throughout childhood. Potential interventions for primary prevention of CD in children, although not completely understood, may offer some benefit. The goals of this article are to discuss in detail these special considerations when dealing with pediatric CD.

Clinical value of duodenal biopsies--beyond the diagnosis of coeliac disease

At upper gastrointestinal endoscopy to investigate unexplained diarrhea and iron deficiency anemia, duodenal biopsies are often taken to exclude a diagnosis of coeliac disease. While histology remains the gold standard for this diagnosis, recent developments in serological testing may overtake this as a first line test and biopsy restricted to confirming the diagnosis. Established coeliac disease on biopsy is straightforward, but early lesions may pose a challenge. Newer endoscopic procedures such as push-pull enteroscopy (balloon enteroscopy) with biopsy allow access to the small bowel beyond the second part of the duodenum. Controversy remains as to what constitutes the normal histology of the duodenum, and small bowel. Lymphocytic duodenosis (increased intraepithelial lymphocytes with normal villous architecture) in patients with negative coeliac serology can be associated with Helicobacter pylori, drugs, autoimmune and other diseases including food allergy. Full thickness small intestinal biopsies can aid in investigation of enteric neuropathies in severe dysmotility disorders. Biopsies are also taken to investigate malabsorption due to suspected infectious and metabolic disorders. Despite highly active anti-retroviral therapy (HAART), immunosuppressed patients may be affected by duodenal pathogens. The histology of duodenal mucosa in acid related disorders reflects the damage seen at endoscopy. Although the prevalence of duodenal ulcer disease is decreasing, drugs causing ulceration remain an important disease entity. Recent observations in functional bowel disorders suggest that the duodenum may be a key site for pathology. In functional dyspepsia, patients with early satiety may have excess eosinophil infiltration, and the mast cell is probably a key player in the irritable syndrome in the small intestine.

Ages of celiac disease: From changing environment to improved diagnostics

From the time of Gee’s landmark writings, the recent history of celiac disease (CD) can be divided into many ages, each driven by a diagnostic advance and a deeper knowledge of disease pathogenesis. At the same time, these advances were paralleled by the identification of new clinical patterns associated with CD and by a continuous redefinition of the prevalence of the disease in population. In the beginning, CD was considered a chronic indigestion, even if the causative food was not known; later, the disease was proven to depend on an intolerance to wheat gliadin, leading to typical mucosal changes in the gut and to a malabsorption syndrome. This knowledge led to curing the disease with a gluten-free diet. After the identification of antibodies to gluten (AGA) in the serum of patients and the identification of gluten-specific lymphocytes in the mucosa, CD was described as an immune disorder, resembling a chronic “gluten infection”. The use of serological testing for AGA allowed identification of the higher prevalence of this disorder, revealing atypical patterns of presentation. More recently, the characterization of autoantibodies to endomysium and to transglutaminase shifted the attention to a complex autoimmune pathogenesis and to the increased risk of developing autoimmune disorders in untreated CD. New diagnostic assays, based on molecular technologies, will introduce new changes, with the promise of better defining the spectrum of gluten reactivity and the real burden of gluten related-disorders in the population. Herein, we describe the different periods of CD experience, and further developments for the next celiac age will be proposed.

Dynamics of non-conventional intraepithelial lymphocytes-NK, NKT, and γδ T-in celiac disease: relationship with age, diet, and histopathology

BACKGROUND

Intraepithelial lymphocytes (IEL) are a heterogeneous population of lymphocytes raised in celiac disease (CD), whose role in CD pathogenesis remains to be defined.

AIMS

To investigate how the age of diagnosis, diet, and the severity of the histological lesions are related to the changes observed in unconventional IEL populations.

METHODS

Prospective analysis of 101 confirmed celiac patients from a single center, including 66 at diagnosis (45 children, 21 adults) and 112 non-celiac controls (12 children, 100 adults). IEL from duodenal biopsies were studied by six-color flow cytometry. The results were analyzed in relationship with age, diet (gluten intake), and histopathology (Marsh type).

RESULTS

In comparison with respective age controls, both children and adult patients showed duodenal intraepithelial lymphocytosis with significant differences in every single non-conventional IEL population: CD3+ TCR γδ, NK (CD3-, CD16+, CD56+), NKT (CD3+, CD161+, CD56+), and iNKT (CD3+ Vα24) (P < 0.001 for all). Gluten intake was not only directly associated with severe atrophy, but also with decreased percentages of NK (P = 0.02), NKT (P = 0.003), and iNKT (P = 0.03). Changes in iNKT and γδ IEL were more marked in celiac children compared with celiac adults (P = 0.02 and 0.01, respectively). In contrast, increased CD3+ TCR γδ were diet- and Marsh grade-independent.

CONCLUSIONS

The typical phenotypical profile of intraepithelial lymphocytosis in untreated pediatric and adult celiacs consists of increased CD3+ TCR γδ populations with decreased NK, NKT, and iNKT cells. NK, NKT, and iNKT IEL, but not γδ IEL, are dynamic populations associated with diet, age, and histopathology.

[Histopathology of coeliac disease]

Coeliac disease is a common disease, affecting 1% of the population. Clinical manifestations are multiple. The diagnosis requires serologic testing and a duodenal biopsy that shows the characteristic findings of intraepithelial lymphocytosis, crypt hyperplasia and villous atrophy, and a positive response to a gluten-free diet. In most patients, the histological diagnosis is easily established. Pitfalls in the pathological diagnosis include a poorly orientated biopsy specimen, either an inadequate biopsy sampling in patients with patchy villous atrophy and the other causes of villous atrophy. A non-response to the gluten-free diet needs to reassess first, the initial diagnosis, second to be sure of the gluten-free diet adherence, and third, to exclude malignant complications such as refractory celiac disease or enteropathy-associated T-cell lymphoma.

Celiac disease: diagnostic criteria in progress

Until a few years ago, celiac disease (CD) was thought to be a rare food intolerance that was confined to childhood and characterized by severe malabsorption and flat intestinal mucosa. Currently, CD is regarded as an autoimmune disorder that is common in the general population (affecting 1 in 100 individuals), with possible onset at any age and with many possible presentations. The identification of CD is challenging because it can begin not only with diarrhea and weight loss but also with atypical gastrointestinal (constipation and recurrent abdominal pain) and extra-intestinal symptoms (anemia, raised transaminases, osteoporosis, recurrent miscarriages, aphthous stomatitis and associated autoimmune disorders), or it could be completely symptomless. Over the last 20 years, the diagnostic accuracy of serology for CD has progressively increased with the development of highly reliable tests, such as the detection of IgA tissue transglutaminase and antiendomysial and IgG antideamidated gliadin peptide antibodies. The routine use of antibody markers has allowed researchers to discover a very high number of 'borderline' cases, characterized by positive serology and mild intestinal lesions or normal small intestine architecture, which can be classified as potential CD. Therefore, it is evident that the 'old celiac disease' with flat mucosa is only a part of the spectrum of CD. It is possible that serology could identify CD in its early stages, before the appearance of severe intestinal damage. In cases with a positive serology but with mild or absent intestinal lesions, the detection of HLA-DQ2 and HLA-DQ8 can help reinforce or exclude the diagnosis of gluten sensitivity.

Gluten tolerance; potential challenges in treatment strategies

Tolerable gluten thresholds in gluten free products have long been debated together with issues of cross contamination of gluten free cereals during the milling process. It is well established that a totally gluten free diet is virtually impossible owing to the presence of traces of gluten. It is estimated that daily consumption of gluten from contaminated gluten free foods is in the range of 5 to 50 mg. We believe evidence is mounting that it may be possible for some coeliac patients to tolerate gluten above the limits considered permissible at threshold levels. Conversely, it seems there is evidence that some patients might have a much lower threshold for gluten. Whatever would be the individual threshold, GFD may be of benefit to any symptomatic patients even those with milder enteropathy like microscopic enteritis.

An update in the diagnosis of coeliac disease

Coeliac disease is increasing in prevalence, which is currently estimated at one in 100 of the population and may occur de novo in adults. The diagnosis requires a joint clinicopathological approach; the recommended first-line test is serology with immunoglobulin A (IgA) tissue transglutaminase and IgA endomysial antibodies. These serological tests show high levels of sensitivity and specificity, but biopsy is the gold standard to confirm the diagnosis. It is important that both tests are performed before the introduction of a gluten-free diet. Although the classical histopathology changes of coeliac disease with partial or total villous atrophy are well recognized, the pathology classification of coeliac disease is changing, with recognition that coeliac disease may show minimal pathology (normal architecture and an intraepithelial lymphocyte count/100 enterocytes ≥ 25). This entity is also described as lymphocytic duodenosis, and recommendation of follow-up serology testing is paramount in this condition. Follow-up of patients with coeliac disease is warranted, as normal serology does not predict mucosal recovery. Failure to heal predicts risk of progression to refractory coeliac disease and malignancies. Refractory coeliac disease occurs in 1-2% of patients and this diagnosis requires a combined clinical and histopathology approach with immunocytochemistry.

Gluten-sensitive enteropathy (celiac disease): controversies in diagnosis and classification

CONTEXT

Celiac disease, or gluten-sensitive enteropathy, is a chronic inflammatory disorder of the small intestine characterized by malabsorption after ingestion of gluten in individuals with a certain genetic background. Clinical presentation can vary from full-blown malabsorption to subtle and atypical symptoms. Diagnosis currently relies on clinicopathologic studies including mucosal biopsy, serologic tests, and the effects of a diet free of gluten on the symptoms. Mucosal pathologic features are also variable, ranging from mild abnormalities, including intraepithelial lymphocytosis, to completely flat mucosa. Since patients with minimal histologic lesion of intraepithelial lymphocytosis often present with normal serologic findings, biopsy diagnosis becomes more important for identifying such individuals. Classification of mucosal pathology in gluten-sensitive enteropathy has been a subject of controversy among pathologists and needs to be revised according to the current understanding of the disease.

OBJECTIVES

To highlight the variations in clinical and pathologic presentation of gluten-sensitive enteropathy, to emphasize the importance of small-intestinal biopsy evaluation in the diagnosis, and to propose a new classification of mucosal pathology in gluten-sensitive enteropathy, in an effort to overcome the problems related to the classification systems currently available.

DATA SOURCES

A review of the literature on clinicopathologic features and the morphologic spectrum of gluten-sensitive enteropathy is presented.

CONCLUSIONS

Considering that there are many entities in the differential diagnosis of gluten-sensitive enteropathy, because of the varied clinicopathologic spectrum of the disease, diagnosis depends on good clinicopathologic communication. The classification that is presented in this review is a simple and practical approach to improve clinicopathologic correlation in gluten-sensitive enteropathy.

Detection of celiac disease and lymphocytic enteropathy by parallel serology and histopathology in a population-based study

BACKGROUND & AIMS

Although serologic analysis is used in diagnosis of celiac disease, histopathology is considered most reliable. We performed a prospective study to determine the clinical, pathologic, and serologic spectrum of celiac disease in a general population (Kalixanda study).

METHODS

A random sample of an adult general population (n = 1000) was analyzed by upper endoscopy, duodenal biopsy, and serologic analysis of tissue transglutaminase (tTg) levels; endomysial antibody (EMA) levels were analyzed in samples that were tTg+. The cut off values for diagnosis of celiac disease were villous atrophy with 40 intraepithelial lymphocytes (IELs)/100 enterocytes (ECs).

RESULTS

Samples from 33 subjects were tTg+, and 16 were EMA+. Histologic analysis identified 7 of 1000 subjects (0.7%) with celiac disease; all were tTg+, and 6 of 7 were EMA+. Another 26 subjects were tTg+ (7/26 EMA+). This was addressed by a second quantitative pathology study (nested case control design) using a threshold of 25 IELS/100 ECs. In this analysis, all 13 samples that were tTg+ and EMA+ had > or =25 IELs/100 ECs. In total, 16 subjects (1.6%) had serologic and histologic evidence of gluten-sensitive enteropathy. IELs were quantified in duodenal biopsy samples from seronegative individuals (n = 500); 19 (3.8%) had >25 IELs and lymphocytic duodenosis.

CONCLUSIONS

Measurement of > or =25 IELs/100 ECs correlated with serologic indicators of celiac disease; a higher IEL threshold could miss 50% of cases. Quantification of tTg is a sensitive test for celiac disease; diagnosis can be confirmed by observation of > or =25 IELs/100ECs in duodenal biopsy specimens. Lymphocytic enteropathy (celiac disease and lymphocytic duodenosis) is common in the population (5.4%).

Tissue-mediated control of immunopathology in coeliac disease

Coeliac disease is an inflammatory disorder with autoimmune features that is characterized by destruction of the intestinal epithelium and remodelling of the intestinal mucosa following the ingestion of dietary gluten. A common feature of coeliac disease and many organ-specific autoimmune diseases is a central role for T cells in causing tissue destruction. In this Review, we discuss the emerging hypothesis that, in coeliac disease, intestinal tissue inflammation--induced either by infectious agents or by gluten--is crucial for activating T cells and eliciting their tissue-destructive effector functions.

High density of intraepithelial gammadelta lymphocytes and deposits of immunoglobulin (Ig)M anti-tissue transglutaminase antibodies in the jejunum of coeliac patients with IgA deficiency

The diagnosis of coeliac disease (CD) represents a special challenge in selective immunoglobulin (Ig)A deficiency (IgAD). A high density of T cell receptor (TCR)gammadelta(+) intraepithelial lymphocytes (IELs) and intestinal IgA anti-tissue transglutaminase 2 (anti-TG2) antibody deposits are suggestive of CD. We analysed the density of TCRgammadelta(+) IELs and the deposition of IgM anti-TG2 antibodies in the jejunal mucosa of IgAD patients with and without CD. Immunohistochemical analyses for the number of CD3+ and TCRgammadelta(+) IELs and double immunofluorescence assay for IgM anti-TG2 antibody deposits were performed in biopsies from 25 children with IgAD (nine untreated CD, seven potential CD and nine without CD). Sixteen immunologically intact children without CD represented the controls. IgAD without CD had a higher number of CD3+ and TCRgammadelta(+) IELs than controls (P < 0.05), but lower than IgAD with CD (P < 0.01). No significant differences were noted between IgAD subjects without CD and those with potential CD. Furthermore, IgAD patients without CD showed a higher TCRgammadelta(+)/CD3+ ratio than the control group (P < 0.05), while the ratio was similar to subjects with CD and potential CD. Intestinal IgM anti-TG2 antibody deposits were present in six of seven of the IgAD patients with untreated CD, one of seven with potential CD and none of those without CD. Most of the patients with IgAD show immune activation in the jejunal mucosa. IgM anti-TG2 antibody deposits are present only in CD. Intestinal IgM anti-TG2 and immunohistochemical markers do not discriminate between IgAD and potential CD with IgAD. Therefore, the serum IgG CD-associated autoantibodies remains very important for the diagnosis of CD in IgAD.

Microscopic enteritis: novel prospect in coeliac disease clinical and immuno-histogenesis. Evolution in diagnostic and treatment strategies

The diagnosis of coeliac disease has traditionally depended on symptoms and intestinal biopsies; nowadays, the diagnosis has been expanded to include an array of serological markers and subtle microscopic lesions. The most important advance in classifying mucosal lesions in coeliac disease was forwarded by Marsh (1992), who provided the biological explanation of how the small bowel reacts to a variety of environmental antigenic challenges including gluten. In the modified version of this classification (Arnhem 1998-1999) autoantibodies have integrated into Marsh's histopathological scheme. As a large part of the coeliac 'iceberg' remains unrecognised, the difficulties in diagnosis continue to challenge clinicians and researchers. Advances in immuno-histochemistry and discovery of the other sensitive markers have acquainted us with so-called Microscopic enteritis, the distinctive subtle abnormalities behind the atypical gluten sensitivity symptoms that often remain unrecognised. Current diagnostic pathways do not always include facilities for looking for this common histological feature in atypical cases. This is essential since improving of the detection rate has been shown to be directly proportional to recognition of cases with milder or minimal mucosal abnormalities. In this revision, we will define and characterise microscopic enteritis as the entity behind a wide range of unexplained gastrointestinal symptoms. Screening for this subtle and distinctive presentation in small bowel pathology will open a new prospect in recognising the most common but unrecognised atypical forms of symptomatic gluten related enteropathies.

Celiac disease: from oral tolerance to intestinal inflammation, autoimmunity and lymphomagenesis

Celiac disease is a multifactorial disorder and provides a privileged model to decipher how the interplay between environmental and genetic factors can alter mucosal tolerance to a food antigen, lead to chronic intestinal inflammation, and ultimately promote T-cell lymphomagenesis. Here we summarize how HLA-DQ2/8 molecules, the main genetic risk factor for this disease can orchestrate a CD4(+) T-cell adaptive immune response against gluten, and discuss recent data which shed light on the innate and adaptive immune stimuli that collaborate to induce a proinflammatory TH1 response, a massive expansion of intraepithelial lymphocytes, and a cytolytic attack of the epithelium. The intestinal immune response driven in genetically predisposed patients by chronic exposure to gluten emerges as the pathological counterpart of normal acute intestinal responses to intracellular pathogens.

The presence of small intestinal intraepithelial gamma/delta T-lymphocytes is inversely correlated with lymphoma development in refractory celiac disease

BACKGROUND

In refractory celiac disease (RCD) type II, a phenotypically aberrant (CD7+ CD3- CD4/8-cytoplasmicCD3+) intraepithelial lymphocyte (IEL) population is present, and 50-60% of these patients develop enteropathy-associated T-cell lymphoma (EATL). TCRgammadelta+ IELs play an important role in mucosal repair, homeostasis, and tumor surveillance. Recently, human small intestinal TCRgammadelta+ IELs were shown to have regulatory potential in uncomplicated celiac disease (CD).

AIM

In the present study, we investigated whether TCRgammadelta+ IELs are decreased in RCD II, providing a possible explanation for persisting mucosal damage and inflammation, and the emergence of aberrant T cells with clonal expansion to EATL.

DESIGN AND METHODS

Multiparameter flow cytometric immunophenotyping was performed on IELs isolated from fresh small bowel biopsy specimens of relatively large distinct CD patient and control groups (N = 87).

RESULTS

A significantly lower percentage of TCRgammadelta+ IELs was found in RCD II as compared to all other CD groups. In contrast, in uncomplicated CD patients significantly more TCRgammadelta+ IELs were found than in controls. Overall, there is a clear negative relation between TCRgammadelta+ IELs and aberrant IELs. Interestingly, TCRgammadelta+ IELs increase again in RCD II after effective therapy.

CONCLUSIONS

The observed negative relation between TCRgammadelta+ and aberrant IELs, along with their known regulatory capacity in uncomplicated CD, implies that TCRgammadelta+ IELs may play a crucial role in mucosal repair, regaining homeostasis and possibly even tumor surveillance. These cells may be important markers, in addition to the aberrant T cells, to differentiate between disease categories and to evaluate the effectiveness of therapeutic strategies.

Immunoglobulin A anti-tissue transglutaminase antibody deposits in the small intestinal mucosa of children with no villous atrophy

OBJECTIVES

Anti-tissue transglutaminase (anti-TG2) immunoglobulin A (IgA) autoantibodies are detectable in the serum of most patients with untreated celiac disease (CD). Their deposits in the intestine of patients with CD with severe enteropathy are considered specific for this condition. The histological spectrum of CD includes cases with normal villous architecture. The aim of this study was to look for anti-TG2 IgA deposits in the intestine of children with normal villous architecture and to relate them with other markers of gluten sensitivity.

PATIENTS AND METHODS

A total of 57 children with normal duodenal villous architecture and markers of gluten sensitivity were considered. Of those, 39 showed positive serum anti-endomysium antibodies and/or high levels of anti-TG2 antibodies (group 1), and 18 were seronegative with only a greater density of gammadelta intraepithelial lymphocytes (group 2). Thirty-four children with no markers of gluten sensitivity and a normal mucosa represented the control group (group 3). The duodenal sections of all patients were investigated for deposited anti-TG2 IgA by double immunofluorescence. Human lymphocyte antigen molecular typing was performed.

RESULTS

In group 1 and in group 2, 33 of 39 children (85%) and 12 of 18 children (66%) showed subepithelial anti-TG2 IgA intestinal deposits, respectively. Only in 3 of 34 (8.8%) children with no markers of gluten sensitivity were anti-TG2 IgA deposits noted.

CONCLUSIONS

A subgroup of children with no serum CD-associated autoantibodies, but greater density of gammadelta intraepithelial lymphocytes, shows a clear anti-TG2 IgA deposition in the duodenal mucosa. These children must be investigated further for possible gluten sensitivity.

The absence of a mucosal lesion on standard histological examination does not exclude diagnosis of celiac disease

Some patients with undiagnosed celiac disease have minor mucosal lesions that may not be apparent during routine histological analysis. Twenty-five such patients of our institution were discharged to their primary-care physicians despite having positive endomysial antibody serology. To re-evaluate diagnosis for these patients, immunohistological staining with antibodies to CD2, CD3, CD7, CD8, CD69, and Ki67 was conducted on original biopsies from twenty patients. Clinical, serological, and histological investigations were offered to all fourteen patients who attended for review. We observed a significantly greater (P < 0.0001) numbers of intraepithelial lymphocytes and Ki67-positive enterocytes in sections from these twenty patients than for normal controls. Of the fourteen patients who attended for further review, firm diagnosis of celiac disease was made for seven patients and diagnosis was likely for another two. Our study clearly revealed that over-reliance on standard histological findings results in failure to diagnose celiac disease.

Small intestinal CD8+TCRgammadelta+NKG2A+ intraepithelial lymphocytes have attributes of regulatory cells in patients with celiac disease

Intraepithelial lymphocytes (IELs) bearing the gammadelta TCR are more abundant in the small intestinal mucosa of patients with celiac disease (CD) compared with healthy individuals. However, their role in disease pathogenesis is not well understood. Here, we investigated the functional attributes of TCRgammadelta+ IELs isolated from intestinal biopsies of patients with either active celiac disease (ACD) or those on a gluten-free diet (GFD). We found that compared with individuals with ACD, individuals on GFD have a higher frequency of CD8+TCRgammadelta+ IELs that express the inhibitory NK receptor NKG2A and intracellular TGF-beta1. TCR triggering as well as cross-linking of NKG2A increased both TGF-beta1 intracellular expression and secretion in vitro. Coculture of sorted TCRgammadelta+NKG2A+ IELs, IL-15-stimulated TCRalphabeta+ IELs, and HLA-E+ enterocytes resulted in a decreased percentage of cytotoxic CD8+TCRalphabeta+ IELs expressing intracellular IFN-gamma and granzyme-B and surface NKG2D. This inhibition was partially abrogated by blocking either TGF-beta alone or both NKG2A and HLA-E. Thus, our data indicate that suppression was at least partially mediated by TGF-beta secretion as a result of engagement of NKG2A with its ligand, HLA-E, on enterocytes and/or TCRalphabeta+ IELs. These findings demonstrate that human small intestinal CD8+TCRgammadelta+ IELs may have regulatory potential in celiac disease.

Latent coeliac disease or coeliac disease beyond villous atrophy?

New diagnostic criteria for coeliac disease are warranted

Long-term follow-up of 61 coeliac patients diagnosed in childhood: evolution toward latency is possible on a normal diet

BACKGROUND/AIMS

Whether a life-long gluten-free diet (GFD) is necessary in all children with diagnosed coeliac disease (CD) remains debated. To address this question, a retrospective analysis of the clinical and biological status of adult coeliac patients diagnosed in childhood, who remained on a normal diet after gluten challenge and were clinically silent, was carried out.

METHODS

Patients aged 18-65 years with CD diagnosed in childhood were included. Clinical status, gluten intake, biological parameters of malabsorption, bone mineral density, human leucocyte antigen (HLA) genotype, serological markers of CD, and histological and immunohistochemical parameters in duodenal biopsies were recorded.

RESULTS

Sixty-one patients had resumed a normal diet and were asymptomatic. Forty-eight showed different degrees of villous atrophy (silent CD), while 13 had no detectable atrophy (latent CD) on duodenal biopsies. Latent CD patients had significantly less osteopenia/osteoporosis (1/9 (11%) vs 23/33 (70%), p<0.001)), and lower T cell receptor (TCR) alphabeta+ intraepithelial T cell counts (38+/-20 vs 55+/-15, p<0.01) than silent CD patients. The mean age at diagnosis and first GFD was lower in latent than in silent patients (14.4+/-5 vs 40.1+/-47 months, p<0.05). Latent patients did not differ significantly from the seven control patients on a long-term GFD, except for a higher frequency of CD-specific serum antibodies. However, two latent patients relapsed clinically and histologically during subsequent follow-up.

CONCLUSIONS

Long-term latency developed in about 20% of CD patients who remained symptom free after gluten reintroduction. This latency can be transient and thus a regular follow-up is mandatory. In silent patients, the increased risk of osteoporosis substantiates the need for a GFD.

ADAM-15/metargidin mediates homotypic aggregation of human T lymphocytes and heterotypic interactions of T lymphocytes with intestinal epithelial cells

Intestinal epithelial cells (IEC) play an immunoregulatory role in the intestine. This role involves cell-cell interactions with intraepithelial lymphocytes that may also play a role in some enteropathies. The discovery of the RGD motif-containing Protein ADAM-15 (a disintegrin and metalloprotease-15) raises the question of its involvement in these cell-cell interactions. Cell adhesion assays were performed using the Jurkat E6.1 T cell line as a model of T lymphocytes and Caco2-BBE monolayers as a model of intestinal epithelia. Our results show that an anti-ADAM-15 ectodomain antibody inhibited the attachment of Jurkat cells on Caco2-BBE monolayers. Overexpression of ADAM-15 in Caco2-BBE cells enhanced Jurkat cell binding, and overexpression of ADAM-15 in Jurkat cells enhanced their aggregation. Mutagenesis experiments showed that both the mutation of ADAM-15 RGD domain or the deletion of its cytoplasmic tail decreased these cell-cell interactions. Moreover, wound-healing experiments showed that epithelial ADAM-15-mediated Jurkat cell adhesion to Caco2-BBE cells enhances the mechanisms of wound repair. We also found that ADAM-15-mediated aggregation of Jurkat cells increases the expression of tumor necrosis factor-alpha mRNA. These results demonstrate the following: 1) ADAM-15 is involved in heterotypic adhesion of intraepithelial lymphocytes to IEC as well as in homotypic aggregation of T cells; 2) both the RGD motif and the cytoplasmic tail of ADAM-15 are involved for these cell-cell interactions; and 3) ADAM-15-mediated cell-cell interactions are involved in mechanisms of epithelial restitution and production of pro-inflammatory mediators. Altogether these findings point to ADAM-15 as a possible therapeutic target for prevention of inappropriate T cell activation involved in some pathologies.