Duodenal intraepithelial lymphocytosis with normal villous architecture in pediatric patients: Mayo Clinic experience, 2000-2009

Mild Duodenal Mucosal Injury and Increased Type I Interferon Signaling Are Preludes to Celiac Disease

Celiac disease (CeD) is an immune-mediated chronic enteropathy caused by gluten exposure in genetically susceptible individuals. The characteristic histologic features of CeD include increased intraepithelial lymphocytes and villous atrophy. Clinically, a subset of individuals with elevated concentrations of serum tissue transglutaminase (TTG) antibodies have intact duodenal villous architecture at initial endoscopy and biopsy but then progress to CeD over time while on gluten-containing foods. We hypothesized that these rare potential CeD cases with progression can allow us to interrogate histologic and molecular signatures to predict those who subsequently develop CeD and to study the final cascade into the overt lesions of CeD. We retrospectively identified 16 children over a 10-year period with elevated serum TTG antibody concentrations but without significant villous atrophy at index duodenal biopsies, in whom subsequent biopsies confirmed CeD while consuming gluten-containing foods. Their clinical and histologic features were compared with age-, race-, and gender-matched controls including active CeD (n = 28) and non-CeD children (negative TTG antibody, normal histology, n = 35). Transcriptomic analysis was performed on a subset of the index biopsies of potential CeD cases with progression and controls. None of the 16 children with potential CeD with progression had a family history of CeD or presented with poor growth or anemia or had commenced a gluten-free diet at the time of index biopsy. The index biopsies of children with potential CeD with progression had significantly greater prevalence of intraepithelial lymphocytes (81% vs 12%, P = .002) and mild villous atrophy (94% vs 22%, P = .006) compared with non-CeD biopsies; none had severe villous atrophy (P = .002). Transcriptomic analysis demonstrated upregulated type I interferon signaling, Janus kinase (JAK)/signal transducer and activator (STAT) pathway of transcription activation and innate and adaptive immunity in duodenum of potential CeD with progression was comparable to non-CeD but preserved signaling in brush border absorption, transporter functions, and epithelial metabolic functions, compared with active CeD. Our results show for the first time that mild mucosal injury in the duodenum of children with potential CeD with progression is accompanied by upregulation of pathways also activated in CeD. Mild mucosal injury and type I interferon signaling may be the initiating cellular and molecular biomarkers in identifying the subset of potential CeD individuals who would progress to CeD while consuming gluten-containing foods.

American College of Gastroenterology Guidelines Update: Diagnosis and Management of Celiac Disease

This guideline presents an update to the 2013 American College of Gastroenterology Guideline on the Diagnosis and Management of Celiac Disease with updated recommendations for the evaluation and management of patients with celiac disease (CD). CD is defined as a permanent immune-mediated response to gluten present in wheat, barley, and rye. CD has a wide spectrum of clinical manifestations that resemble a multisystemic disorder rather than an isolated intestinal disease, and is characterized by small bowel injury and the presence of specific antibodies. Detection of CD-specific antibodies (e.g., tissue transglutaminase) in the serum is very helpful for the initial screening of patients with suspicion of CD. Intestinal biopsy is required in most patients to confirm the diagnosis. A nonbiopsy strategy for the diagnosis of CD in selected children is suggested and discussed in detail. Current treatment for CD requires strict adherence to a gluten-free diet (GFD) and lifelong medical follow-up. Most patients have excellent clinical response to a GFD. Nonresponsive CD is defined by persistent or recurrent symptoms despite being on a GFD. These patients require a systematic workup to rule out specific conditions that may cause persistent or recurrent symptoms, especially unintentional gluten contamination. Refractory CD is a rare cause of nonresponsive CD often associated with poor prognosis.

Effect of Esophagogastroduodenoscopy Volume and Gastric/Esophageal Pathology on the Rate of Lymphocytic Duodenosis Reporting in Children and Adolescents

Background  It is not clear if the increase in the number of esophagogastroduodenoscopies (EGDs) performed has any significant effect on the rate of lymphocytic duodenosis (LD) reporting in children and adolescents and whether it correlates with abnormal gastric and/or esophageal pathology." Methods  We performed a single-center retrospective study using the Mayo Clinic electronic health record and pathology database. We reviewed all EGD procedures performed in children and adolescents (<18 years) between January 1, 2000, and December 31, 2018, and identified two groups, the LD group and matched age and sex control group (normal duodenal biopsies). We evaluated the correlation of LD rate with the yearly number of EGDs performed and the presence of abnormal gastric and/or esophageal pathology. Results  Of 11,870 EGDs performed, we identified 338 (3%) individuals with LD and 390 (3%) randomly selected controls, with a mean (SD) age of 9.6 (5.3) and 11.7 (5.0) years, respectively. Based on logistic regression analysis, abnormal gastric histology was associated with the presence of LD when compared with controls (odds ratio, 2.85; 95% CI, 2.05-3.97; P  < 0.001). The rate of LD-positive biopsies per year was highly correlated with the number of EGDs performed (ρ = 0.931; 95% CI, 0.826-0.974; P  < 0.001). Conclusion  The rate of LD reporting is correlated with the number of EGDs performed and is more likely seen in children and adolescents with abnormal gastric histology.

Differential diagnosis and long-term outcomes of non-atrophic duodenal changes in children

OBJECTIVES AND STUDY

Gastrointestinal endoscopy is often performed when investigating abdominal complaints in children. While atrophic changes of the duodenal mucosa are usually caused by celiac disease, the prevalence and clinical significance of non-atrophic duodenal changes are less clear. We studied these issues in a large pediatric endoscopic cohort.

METHODS

Comprehensive data on clinical features, diagnostic findings and long-term outcomes of children who had undergone upper gastrointestinal endoscopy with systematic duodenal sampling were collected. Study variables were compared between children with non-atrophic changes and normal histology, and between those with non-atrophic changes who did and did not receive a diagnosis.

RESULTS

The study comprised 1,170 consecutive children, of whom 51 (4.4%) had non-atrophic and 315 (26.9%) atrophic duodenal changes and 804 (68.7%) normal histology. The most common non-atrophic findings were non-specific inflammation (n = 19) and intraepithelial lymphocytosis (n = 14). Patients with non-atrophic changes presented more often with blood in stools (23.5 vs. 11.3%; p = 0.009), anemia (43.2 vs. 36.5%; p = 0.028) and positive celiac serology (34.3 vs. 12.9%; p < 0.001) than those with a normal duodenum. Twenty-four (44%) of those with non-atrophic changes received an initial diagnosis, the most common of which were inflammatory bowel disease (IBD) (n = 8), Helicobacter pylori infection (n = 3) and food allergy (n = 3). The prevalence of the diagnoses did not differ from those with a normal duodenum. Those who received a diagnosis had more often blood in stools (37.5 vs. 11.1%; p = 0.027), anemia (70.6 vs. 20.0%; p = 0.002) and negative celiac serology (50.0 vs. 7.7%; p = 0.013) than those without diagnosis. During a follow-up of 6.1-13.3 years, five of the 12 initially undiagnosed seropositive patients developed celiac disease, and one patient also developed ulcerative colitis.

CONCLUSION

Non-atrophic duodenal changes are relatively common and associated with anemia, blood in stools, and positive celiac disease serology. Excluding potential celiac disease, those without an initial diagnosis have a favorable long-term prognosis.

The Significance and Clinical Outcome of Lymphocytic Duodenosis in Children: Mayo Clinic Experience and Systematic Review

BACKGROUND

Lymphocytic duodenosis (LD) defined as increased intraepithelial lymphocytes >25 intraepithelial lymphocytes (IELs) per 100 epithelial cells with normal villous architecture is associated with many gastrointestinal (GI) disorders. We aim to assess the rate and outcome of LD in children and perform a systematic review.

METHOD

We reviewed all children (<18 years) who underwent esophagogastroduodenoscopy (EGD) with duodenal biopsy between January 2000 and June 2019 to identify LD cases and control group. Demographics, clinical, and pathologic information were reviewed and recorded. A systematic review including our findings was performed.

RESULTS

During the study period 12,744 children underwent an EGD with biopsies. Of those, we identified 426 children with LD (3%) and 474 controls. The median age in years was 10.7 and 12.6 and there were 254 (60%) and 278 (59%) girls in the LD and control group, respectively. The most common presenting symptoms in both groups were abdominal pain (52%), gastroesophageal acid reflux disease (18%), diarrhea (16%), and vomiting (12%). Diarrhea (21% vs 12%, P < 0.001) and constipation (2% vs 0.4%, P = 0.021) were statistically different between the LD and control group, respectively. Median follow-up (range) is 3.6 (0.0, 190.9) and 3.1 (0.0, 194.2) in the LD and control group, respectively. CD (5% vs 0%, P < 0.001), Crohn disease (9% vs 3%, P = 0.003) and Helicobacter pylori gastritis (3% vs 1%, P = 0.021) were more common in the LD group.

CONCLUSIONS

The Rate of LD in children is similar to reported rate in adults. In the absence of Crohn disease, CD or H. Pylori, LD seems to be a benign and transient histologic finding in children.

The role of histopathology in the diagnosis and management of coeliac disease and other malabsorptive conditions

Most absorption of nutrients takes place in the proximal small intestine, and the most common disorders leading to malabsorption are associated with a morphological abnormality in the duodenal mucosa that is appreciable in histological sections of biopsy specimens. Coeliac disease is the most well-known example, causing intraepithelial lymphocytosis, inflammation and villous atrophy in the duodenum. Remarkably similar inflammatory changes can be induced by other processes, including medications, e.g. angiotensin II receptor blockers and immune checkpoint inhibitors, immune dysregulation disorders, e.g. common variable immunodeficiency and autoimmune enteropathy, infections, collagenous sprue, and tropical sprue. However, there are often subtle histological differences from coeliac disease in the type of inflammatory infiltrate, the presence of crypt apoptosis, and the extent and type of inflammation beyond the duodenum. The clinical setting and serological investigation usually allow diagnostic separation, but some cases remain challenging. Histopathology is also important in assessing the response to treatment, such as the change in villous architecture caused by a gluten-free diet, or the response to cessation of a potentially causative medication. This review examines the practical role that histopathology of duodenal biopsy specimens plays in the assessment and management of inflammatory malabsorptive processes of the proximal small intestine, with a particular emphasis on coeliac disease.

Minimal Lesions of the Small Intestinal Mucosa: More than Morphology

Minimal lesions of the small bowel are mucosal changes characterized by an increased number of intraepithelial lymphocytes (with or without crypt hyperplasia) and normal villous architecture. Such changes are associated with a wide spectrum of conditions, ranging from food intolerances to infections, and from drugs to immune diseases, with different clinical profiles and manifestations, which complicates the formulation of a differential diagnosis. Patient history, symptom evaluation, and histopathology are the diagnostic features needed to establish a correct diagnosis. Physicians should assist pathologists in formulating a precise morphological evaluation by taking well-oriented small intestinal biopsies and collecting informative clinical findings that inform histopathology. In this current clinical controversy, the authors provide the reader with an appraisal of the small intestine minimal lesions through a careful analysis of the major conditions (e.g., celiac disease and other non-celiac disorders) responsible for such changes and their differential diagnosis. Also, we acknowledge that some of the diseases detailed in this article may progress from an early minimal lesion to overt mucosal atrophy. Thus, the timing of the diagnosis is of paramount importance.

Daily Dilemmas in Pediatric Gastrointestinal Pathology

The evaluation of gastrointestinal pathology in children often requires a different approach from that in adults. In this concise review, the authors outline 3 diagnostic challenges that are often encountered in daily practice; these include eosinophilic diseases, duodenal intraepithelial lymphocytosis with preserved villous architecture, and terminal ileal inflammation in the setting of idiopathic inflammatory bowel disease.

Prevalence and diagnostic outcomes of children with duodenal lesions and negative celiac serology

BACKGROUND

Celiac disease diagnostics begin by measuring autoantibodies, which may fail to identify seronegative patients. Duodenal lesion in the absence of antibodies is scarcely studied, especially in children.

AIMS

To investigate the prevalence and diagnostic outcomes of children with seronegative duodenal lesion in two countries with different disease profiles.

METHODS

Medical data, including the results of histology and transglutaminase (tTGab) and endomysium (EmA) antibody measurements were collected from 1172 Finnish and 264 Romanian children with systematic duodenal sampling. Database of 509 Finnish children with celiac disease was examined to identify earlier seronegative patients.

RESULTS

Celiac disease was diagnosed in 307 Finnish and 83 Romanian children in the endoscopy cohorts. No seronegative patients were found among 899 celiac disease patients, although some were only tTGab or EmA positive. Non-celiac duodenal lesion was detected in eight Finnish and 32 Romanian children, their most common diagnoses being inflammatory bowel disease and infections, respectively. Six children with morphological lesion received no diagnosis. None of them developed celiac disease during a follow-up of 3-11 years.

CONCLUSION

Pediatric seronegative celiac disease is exceptional in the era of modern autoantibodies. Other reasons for duodenal lesion should therefore be sought, bearing in mind possible differences across countries.

The elusive case of human intraepithelial T cells in gut homeostasis and inflammation

The epithelial barrier of the gastrointestinal tract is home to numerous intraepithelial T cells (IETs). IETs are functionally adapted to the mucosal environment and are among the first adaptive immune cells to encounter microbial and dietary antigens. They possess hallmark features of tissue-resident T cells: they are long-lived nonmigratory cells capable of rapidly responding to antigen challenges independent of T cell recruitment from the periphery. Gut-resident T cells have been implicated in the relapsing and remitting course and persisting low-grade inflammation of chronic gastrointestinal diseases, including IBD and coeliac disease. So far, most data IETs have been derived from experimental animal models; however, IETs and the environmental makeup differ between mice and humans. With advances in techniques, the number of human studies has grown exponentially in the past 5 years. Here, we review the literature on the involvement of human IETs in gut homeostasis and inflammation, and how these cells are influenced by the microbiota and dietary antigens. Finally, targeting of IETs in therapeutic interventions is discussed. Broad insight into the function and role of human IETs in gut homeostasis and inflammation is essential to identify future diagnostic, prognostic and therapeutic strategies.

Capsule endoscopy for patients with coeliac disease

Coeliac disease is an autoimmune mediated condition in response to gluten. A combination of innate and adaptive immune responses results in villous shortening in the small bowel (SB) that can be morphologically picked up on capsule endoscopy. It is the only imaging modality that can provide mucosal views of the entire SB, while histology is generally limited to the proximal SB. Radiological modalities are not designed to pick up changes in villous morphology. Areas covered: In this review, we provide a comprehensive analysis on the justified use of small bowel capsule endoscopy (SBCE) in the assessment of patients with coeliac disease; compare SBCE to histology, serology, and symptomatology; and provide an overview on automated quantitative analysis for the detection of coeliac disease. We also provide insight into future work on SBCE in relation to coeliac disease. Expert commentary: SBCE has opened up new avenues for the diagnosis and monitoring of patients with coeliac disease. However, larger studies with new and established coeliac disease patients and with greater emphasis on morphological features on SBCE are required to better define the role of SBCE in the setting of coeliac disease.

Clinical and Histologic Mimickers of Celiac Disease

Celiac disease is an autoimmune disorder of the small bowel, classically associated with diarrhea, abdominal pain, and malabsorption. The diagnosis of celiac disease is made when there are compatible clinical features, supportive serologic markers, representative histology from the small bowel, and response to a gluten-free diet. Histologic findings associated with celiac disease include intraepithelial lymphocytosis, crypt hyperplasia, villous atrophy, and a chronic inflammatory cell infiltrate in the lamina propria. It is important to recognize and diagnose celiac disease, as strict adherence to a gluten-free diet can lead to resolution of clinical and histologic manifestations of the disease. However, many other entities can present with clinical and/or histologic features of celiac disease. In this review article, we highlight key clinical and histologic mimickers of celiac disease. The evaluation of a patient with serologically negative enteropathy necessitates a carefully elicited history and detailed review by a pathologist. Medications can mimic celiac disease and should be considered in all patients with a serologically negative enteropathy. Many mimickers of celiac disease have clues to the underlying diagnosis, and many have a targeted therapy. It is necessary to provide patients with a correct diagnosis rather than subject them to a lifetime of an unnecessary gluten-free diet.

Intraepithelial lymphocyte immunophenotype: a useful tool in the diagnosis of celiac disease

According to new ESPGHAN guidelines, gluten challenge is considered necessary when there is doubt about the initial diagnosis of celiac disease (CD). The main aim of this study was to quantify intraepithelial lymphocyte (IEL) immunophenotype on celiac patients on gluten-containing diet (GCD) compared to those on gluten-free diet (GFD). Another aim was to evaluate the clinical utility of IELs in the CD diagnosis, especially in selected patients on GFD where diagnostic uncertainty remains. IEL immunophenotype (TCRγδ and NK-like IELs) were studied by flow cytometry in 111 children with CD (81 children with CD on GCD and 30 celiac patients on GFD) and a control group (10 children). Duration of GFD was 5.4 ± 1.6 years. TCRγδ IELs in celiac patients receiving a GCD or GFD were significantly higher (p < 0.001) than in the control group. NK-like IELs in patients receiving a GCD or GFD were significantly lower than in the control group (p < 0.001). We observed a permanent decrease of NK-like IELs and an increment of TCRγδ IELs after following an adequate establishment and compliance of a long-term GFD in celiac patients. Recognition of IELs changes in the intestinal mucosa on celiac patients after long-term establishment of a GFD could constitute a useful tool for CD diagnosis in various situations: in which there is doubt about the initial diagnosis and repeat biopsy is necessary (avoiding the need of gluten challenges), and in those patients with symptoms/signs suggestive of CD who maintain a low gluten diet.

Lymphocytic duodenitis or microscopic enteritis and gluten-related conditions: what needs to be explored?

Microscopic enteritis (ME) is characterized by abnormal infiltration of intraepithelial lymphocytes in intestinal mucosa. It was described as duodenal lymphocytosis or lymphocytic duodenitis until the dedicated Consensus Conference of 2015. ME represents a common feature of several gluten-mediated and non-gluten related diseases; therefore, it is an umbrella term embracing several conditions. The most frequent causes of ME are gluten-related disorders (celiac disease, non-celiac gluten sensitivity, wheat allergy), Helicobacter pylori infection and drug-related damages. Less frequently, ME may be secondary to inflammatory bowel disease, some autoimmune conditions, immunoglobulin deficiencies, blood malignancies, infections and irritable bowel syndrome. Therefore, the differential diagnosis of ME may be challenging. The diagnosis of ME needs to be driven by predominant symptoms and patient history. However, it is often difficult to achieve an immediate identification of the underlying condition, and a broad variety of diagnostic tests may be required. Ultimately, long-term surveillance is needed for a final diagnosis in many cases, since a hidden or quiescent condition may be disclosed after a period of latency. In any case, strict collaboration between the clinician and the pathologist is pivotal. The treatment of ME should be personalized, depending on the underlying disease. For gluten-related conditions (celiac disease, gluten sensitivity, wheat allergy, dermatitis herpetiformis), a gluten-free diet may be proposed. For other conditions, a targeted etiologic treatment is necessary. In conclusion, ME represents a novel entity that is attracting increasing interest. The growing epidemiologic trend confirms that it will become a common condition in clinical practice.

Functional dyspepsia is associated with duodenal eosinophilia in an Australian paediatric cohort

BACKGROUND

The pathophysiology of functional dyspepsia (FD) remains unknown. Duodenal eosinophil infiltration has been reported.

AIM

To assess the association between dyspeptic symptoms and duodenal eosinophilia in children undergoing upper gastrointestinal endoscopy.

METHODS

In this retrospective cohort study, children with normal upper endoscopy and routine histology at a single tertiary paediatric centre between 2010 and 2014 were included. FD was defined as epigastric pain or discomfort >2 months without response to acid suppression. Controls presented with nonerosive reflux disease, dysphagia or rumination syndrome. Intramucosal eosinophil counts were compared between the groups using uni- and multivariate regression analyses.

RESULTS

Thirty-six cases and 36 nonmatched controls were identified. Atopic history (39% vs. 25%) and psychological comorbidity (53% vs. 39%; both P = 0.2) were frequent in cases and controls. Self-reported nausea (64% vs. 17%; P < 0.0001), lethargy (19% vs. 0%; P = 0.005) and family functional gastrointestinal disorder(FGID) (28% vs. 3%; P = 0.003) were more common in cases than controls. Duodenal eosinophil counts [median (IQR): 151 (118-207) vs. 76 (60-106) per mm² ; P < 0.001] were significantly higher in cases than controls with >112 eosinophils per mm² predictive for FD (OR: 33.6, 95% CI: 7.1-159.0; P < 0.001). Duodenal eosinophilia was associated with weight loss (OR: 7.1, 95% CI: 1.1-45.5; P = 0.04).

CONCLUSIONS

Functional dyspepsia in children is strongly associated with duodenal eosinophilia, in the absence of endoscopic or routine histological findings. Frequent atopic and psychological comorbidity illustrate likely multifactorial mechanisms.

Evolutionary Developments in Interpreting the Gluten-Induced Mucosal Celiac Lesion: An Archimedian Heuristic

The evolving history of the small intestinal biopsy and its interpretation—and misinterpretations—are described in this paper. Certain interpretative errors in the technical approaches to histological assessment are highlighted—even though we may never be rid of them. For example, mucosal “flattening” does not reduce individual villi to their cores, as still seems to be widely believed. Neither is the mucosa undergoing an atrophic process—since it can recover structurally. Rather, the intestinal mucosa manifests a vast hypertrophic response resulting in the formation of large plateaus formed from partially reduced villi and their amalgamation with the now increased height and width of the inter-villous ridges: this is associated with considerable increases in crypt volumes. Sections through mosaic plateaus gives an erroneous impression of the presence of stunted, flat-topped villi which continues to encourage both the continued use of irrelevant “atrophy” terminologies and a marked failure to perceive what random sections through mosaic plateaus actually look like. While reviewing the extensive 40+ year literature on mucosal analysis, we extracted data on intraepithelial lymphocytes (IEL) counts from 607 biopsies, and applied receiver-operating characteristic (ROC)-curve analysis. From that perspective, it appears that counting IEL/100 enterocyte nuclei in routine haematoxylin and eosin (H&E) sections provides the most useful discriminator of celiac mucosae at histological level, with an effective cut-off of 27 IEL, and offering a very high sensitivity with few false negatives. ROC-curve analysis also revealed the somewhat lesser accuracies of either CD3⁺ or γδ⁺ IEL counts. Current official guidelines seem to be somewhat inadequate in clearly defining the spectrum of gluten-induced mucosal pathologies and how they could be optimally interpreted, as well as in promoting the ideal manner for physicians and pathologists to interact in interpreting intestinal mucosae submitted for analysis. Future trends should incorporate 3-D printing and computerised modelling in order to exemplify the subtle micro-anatomical features associated with the crypt-villus interzone. The latter needs precise delineation with use of mRNA in-section assays for brush border enzymes such as alkaline phosphate and esterase. Other additional approaches are needed to facilitate recognition and interpretation of the features of this important inter-zone, such as wells, basins and hypertrophic alterations in the size of inter-villous ridges. The 3-D computerised models could considerably expand our understandings of the microvasculature and its changes—in relation both to crypt hypertrophy, in addition to the partial attrition and subsequent regrowth of villi from the inter-villous ridges during the flattening and recovery processes, respectively.

Intraepithelial lymphocytes, scores, mimickers and challenges in diagnosing gluten-sensitive enteropathy (celiac disease)

The upper digestive tract is routinely scoped for several causes of malabsorption, and the number of duodenal biopsy specimens has increased notably in the last 10 years. Gluten-sensitive enteropathy (GSE) is an autoimmune disease, which shows an increasing prevalence worldwide and requires a joint clinico-pathological approach. The classical histopathology of GSE with partial or total villous blunting is well recognized, but the classification of GSE is not straightforward. Moreover, several mimickers of GSE with intraepithelial lymphocytosis have been identified in the last 20 years, with drug interactions and medical comorbidities adding to the conundrum. In this review, we report on the normal duodenal mucosa, the clinical presentation and laboratory diagnosis of GSE, the duodenal intraepithelial lymphocytes and immunophenotype of GSE-associated lymphocytes, the GSE mimickers, the differences "across oceans" among guidelines in diagnosing GSE, and the use of a synoptic report for reporting duodenal biopsies in both children and adults in the 21st century.

May the assessment of baseline mucosal molecular pattern predict the development of gluten related disorders among microscopic enteritis?

AIM

To evaluate mucosal baseline mRNA expression of tissue transglutaminase 2 (tTG2), interferon gamma (IFNγ), toll-like receptor 2 (TLR2) and Myeloid Differentiation factor 88 (MyD88) in patients with microscopic enteritis (ME).

METHODS

We retrospectively enrolled 89 patients with ME of different etiology, which was defined within a 2-year mean period of follow-up. Baseline histological examination was performed on Hematoxylin-Eosin stained sections and CD3 lymphocyte immunohistochemistry was used for intraepithelial lymphocyte count (IELs). ME was defined according to the criteria of Bucharest Consensus Conference. For each patient, formalin embedded biopsy samples of the duodenum referred to the period of ME diagnosis were retrieved. Real-time polymerase chain reaction (RT-PCR) was used to detect the amount of mRNA coding for tTG2, IFNγ, TLR2 and MyD88, and the quantity was expressed as fold change compared to controls. Control group was represented by duodenal normal specimens from 15 healthy subjects undergoing endoscopy for functional symptoms. Comparisons among continuous variables were performed by One way analysis of variance (ANOVA) and Bonferroni's test. The χ(2) test was used for categorical variables. Pearson's test was used to evaluate correlations. Receiver operating curves were drawn for all four markers to estimate sensitivity and specificity in discriminating the development of CD and GS.

RESULTS

After a period of follow up of 21.7 ± 11.7 mo, the following diagnoses were achieved: gluten related disorders in 48 subjects (31 CD; 17 GS) and non-gluten related ones in 41 (29 Irritable Bowel Syndrome - IBS; 12 Others). CD patients had the highest tTG2 levels (8.3 ± 4.5). The ANOVA plus Bonferroni analysis showed that CD > Other ME > GS = IBS > negative controls. A cut off value of 2.258 was able to discriminate between CD and GS with a sensitivity of 52.94% and a specificity of 87.1%. Additionally, CD patients had the highest IFNγ levels (8.5 ± 4.1). ANOVA plus Bonferroni demonstrated CD > Other ME > GS = IBS > negative controls. A cut off of 1.853 was able to differentiate CD and GS with a sensitivity of 47.06% and a specificity of 96.77%. Patients with non gluten-related causes of ME exhibited the highest TLR2 levels (6.1 ± 1.9) as follows: Other ME > CD = GS = IBS > negative controls. TLR2 was unable to discriminate CD from GS. Patients with CD overexpressed MyD88 levels similarly to non gluten-related causes of DL (7.8 ± 4.9 and 6.7 ± 2.9), thus CD = Other ME > GS = IBS > negative controls. A cut off of 3.722 was able to differentiate CD from GS with a sensitivity of 52.94% and a specificity of 74.19%. IELs count (15-25 and more than 25/100 enterocytes) strongly correlated with mRNA levels of all tested molecules (P < 0.0001).

CONCLUSION

Our results confirm that a single marker is unable to predict a discrimination among ME underlying conditions as well as between CD and GS. Mucosal high levels of tTG and IFNγ mRNA may predict the development of CD more than GS with high specificity, despite an expected low sensitivity. TLR2 does not discriminate the development of CD from GS. MyD88 levels indicate that intestinal permeability is more increased when a severe intestinal damage underlies ME in both gluten related and unrelated conditions. Therefore, the results of the present paper do not seem to show a clear translational value.

Seronegative Celiac Disease and Immunoglobulin Deficiency: Where to Look in the Submerged Iceberg?

In the present narrative review, we analyzed the relationship between seronegative celiac disease (SNCD) and immunoglobulin deficiencies. For this purpose, we conducted a literature search on the main medical databases. SNCD poses a diagnostic dilemma. Villous blunting, intraepithelial lymphocytes (IELs) count and gluten "challenge" are the most reliable markers. Immunohistochemistry/immunofluorescence tissue transglutaminase (tTG)-targeted mucosal immunoglobulin A (IgA) immune complexes in the intestinal mucosa of SNCD patients may be useful. In our experience, tTG-mRNA was similarly increased in seropositive celiac disease (CD) and suspected SNCD, and strongly correlated with the IELs count. This increase is found even in the IELs' range of 15-25/100 enterocytes, suggesting that there may be a "grey zone" of gluten-related disorders. An immune deregulation (severely lacking B-cell differentiation) underlies the association of SNCD with immunoglobulin deficiencies. Therefore, CD may be linked to autoimmune disorders and immune deficits (common variable immunodeficiency (CVID)/IgA selective deficiency). CVID is a heterogeneous group of antibodies dysfunction, whose association with CD is demonstrated only by the response to a gluten-free diet (GFD). We hypothesized a familial inheritance between CD and CVID. Selective IgA deficiency, commonly associated with CD, accounts for IgA-tTG seronegativity. Selective IgM deficiency (sIgMD) is rare (<300 cases) and associated to CD in 5% of cases. We diagnosed SNCD in a patient affected by sIgMD using the tTG-mRNA assay. One-year GFD induced IgM restoration. This evidence, supporting a link between SNCD and immunoglobulin deficiencies, suggests that we should take a closer look at this association.

Evolution of nonspecific duodenal lymphocytosis over 2 years of follow-up

AIM

To assess the evolution of duodenal lymphocytosis (DL), a condition characterized by increased intraepithelial lymphocytes (IELs), over 2 years of follow-up.

METHODS

Consecutive patients undergoing upper endoscopy/histology for abdominal pain, diarrhea, weight loss, weakness or other extraintestinal features compatible with celiac disease (CD) were included. Evaluation of IELs infiltrate in duodenal biopsy samples was carried out by CD3-immunohistochemistry and expressed as number of positive cells/100 enterocytes. Diagnostic agreement on the IELs count was tested by calculating the weighted k coefficient. All patients underwent serological detection of autoantibodies associated with CD: IgG and IgA anti-tissue transglutaminase and endomysium. Each patient underwent further investigations to clarify the origin of DL at baseline and/or in the course of 2 years of follow-up every six months. Autoimmune thyroiditis, intestinal infections, parasitic diseases, bacterial intestinal overgrowth, hypolactasia and wheat allergy were detected. Colonoscopy and enteric magnetic resonance imaging were performed when necessary. Risk factors affecting the final diagnosis were detected by multinomial logistic regression and expressed as OR.

RESULTS

Eighty-five patients (16 males, 69 females, aged 34.1 ± 12.5 years) were followed up for a mean period of 21.7 ± 11.7 mo. At baseline, endoscopy/duodenal biopsy, CD3 immunohistochemistry revealed: > 25 IELs/100 enterocytes in 22 subjects, 15-25 IELs in 37 and < 15 IELs in 26. They all had negative serum anti-transglutaminase and anti-endomysium, whilst 5 showed IgG anti-gliadin positivity. In the course of follow-up, 23 developed CD seropositivity and gluten sensitivity (GS) was identified in 19. Other diagnoses were: 5 Helicobacter pylori infections, 4 jejunal Crohn's disease, 1 lymphocytic colitis and 1 systemic sclerosis. The disease in the remaining 32 patients was classified as irritable bowel syndrome because of the lack of diagnostic evidence. At multivariate analysis, the evolution towards CD was associated with an IELs infiltrate > 25 (OR = 1640.4) or 15-25 (OR = 16.95), human leukocyte antigen (HLA) DQ2/8 (OR = 140.85) or DQA1*0501 (OR = 15.36), diarrhea (OR = 5.56) and weakness (OR = 11.57). GS was associated with IELs 15-25 (OR = 28.59), autoimmune thyroiditis (OR = 87.63), folate deficiency (OR = 48.53) and diarrhea (OR = 54.87).

CONCLUSION

DL may have a multifactorial origin but the IELs infiltrate and HLA are strong predictive factors for CD development and a clinical diagnosis of GS.

Adaptive diagnosis of coeliac disease

Coeliac disease has for a long time simply been regarded as a gluten-dependent enteropathy and a duodenal biopsy was required in all patients for the diagnosis. It is now accepted that autoimmunity against transglutaminase 2 is an earlier, more universal and more specific feature of coeliac disease than histologic lesions. Moreover, high serum levels of combined anti-transglutaminase 2 and anti-endomysium antibody positivity have excellent predictive value for the presence of enteropathy with villous atrophy. This makes the histology evaluation of the gut no longer necessary in well defined symptomatic paediatric patients with compatible HLA-DQ2 and/or DQ8 background. The biopsy-sparing diagnostic route is not yet recommended by gastroenterologists for adults, and certain clinical circumstances (immunodeficiency conditions, extraintestinal manifestations, type-1 diabetes mellitus, age less than 2 years) may require modified diagnostic approaches. Coeliac patients with preserved duodenal villous structure do exist and these need a more extended evaluation by immunologic and molecular biology tools.

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.

Normal villous architecture with increased intraepithelial lymphocytes: a duodenal manifestation of Crohn disease

OBJECTIVES

To assess a possible association between inflammatory bowel disease (IBD) and the histologic finding in duodenal biopsy specimens of increased intraepithelial lymphocytes (IELs) with normal villous architecture.

METHODS

We identified all patients with duodenal biopsy specimens obtained between 2000 and 2010 showing increased IELs and normal architecture. Among the 74 such patients who also had IBD, we characterized the clinical features of IBD and reviewed all available upper gastrointestinal biopsy specimens.

RESULTS

Fifty-eight patients had Crohn disease, 13 had ulcerative colitis, and three had IBD, type unclassified. No duodenal sample with increased IELs had other histologic features of IBD. Among gastric biopsy specimens from 34 patients with Crohn disease, nearly half (16) had focal gastritis.

CONCLUSIONS

We propose that Crohn disease be included in the differential diagnosis for increased IELs with normal villous architecture in duodenal biopsy specimens, particularly when gastric biopsy specimens show focal gastritis.

Duodenal lymphocytosis with no or minimal enteropathy: much ado about nothing?

Duodenal lymphocytosis is a nonspecific finding that is being detected with heightened frequency. Although increased intraepithelial lymphocytosis with normal villous architecture classically corresponds to grade 1 of the Marsh classification, many other conditions have been reported to be associated with this histologic pattern. In this article, we offer a broad review of the associations of isolated increased intraepithelial lymphocytosis with celiac and nonceliac gluten sensitivity, as well as of the broadening nonceliac etiologies.

ACG clinical guidelines: diagnosis and management of celiac disease

This guideline presents recommendations for the diagnosis and management of patients with celiac disease. Celiac disease is an immune-based reaction to dietary gluten (storage protein for wheat, barley, and rye) that primarily affects the small intestine in those with a genetic predisposition and resolves with exclusion of gluten from the diet. There has been a substantial increase in the prevalence of celiac disease over the last 50 years and an increase in the rate of diagnosis in the last 10 years. Celiac disease can present with many symptoms, including typical gastrointestinal symptoms (e.g., diarrhea, steatorrhea, weight loss, bloating, flatulence, abdominal pain) and also non-gastrointestinal abnormalities (e.g., abnormal liver function tests, iron deficiency anemia, bone disease, skin disorders, and many other protean manifestations). Indeed, many individuals with celiac disease may have no symptoms at all. Celiac disease is usually detected by serologic testing of celiac-specific antibodies. The diagnosis is confirmed by duodenal mucosal biopsies. Both serology and biopsy should be performed on a gluten-containing diet. The treatment for celiac disease is primarily a gluten-free diet (GFD), which requires significant patient education, motivation, and follow-up. Non-responsive celiac disease occurs frequently, particularly in those diagnosed in adulthood. Persistent or recurring symptoms should lead to a review of the patient's original diagnosis to exclude alternative diagnoses, a review of the GFD to ensure there is no obvious gluten contamination, and serologic testing to confirm adherence with the GFD. In addition, evaluation for disorders associated with celiac disease that could cause persistent symptoms, such as microscopic colitis, pancreatic exocrine dysfunction, and complications of celiac disease, such as enteropathy-associated lymphoma or refractory celiac disease, should be entertained. Newer therapeutic modalities are being studied in clinical trials, but are not yet approved for use in practice. Given the incomplete response of many patients to a GFD-free diet as well as the difficulty of adherence to the GFD over the long term, development of new effective therapies for symptom control and reversal of inflammation and organ damage are needed. The prevalence of celiac disease is increasing worldwide and many patients with celiac disease remain undiagnosed, highlighting the need for improved strategies in the future for the optimal detection of patients.