Clinical, endoscopic, and histological differentiation between celiac disease and tropical sprue: A systematic review

Advances in Nonresponsive and Refractory Celiac Disease

Nonresponsive celiac disease (CeD) is relatively common. It is generally attributed to persistent gluten exposure and resolves after correction of diet errors. However, other complications of CeD and disorders clinically mimicking CeD need to be excluded. Novel therapies are being evaluated to facilitate mucosal recovery, which might benefit patients with nonresponsive CeD. Refractory CeD (RCeD) is rare and is divided into 2 types. The etiology of type I RCeD is unclear. A switch to gluten-independent autoimmunity is suspected in some patients. In contrast, type II RCeD represents a low-grade intraepithelial lymphoma. Type I RCeD remains a diagnosis of exclusion, requiring ruling out gluten intake and other nonmalignant causes of villous atrophy. Diagnosis of type II RCeD relies on the demonstration of a clonal population of neoplastic intraepithelial lymphocytes with an atypical immunophenotype. Type I RCeD and type II RCeD generally respond to open-capsule budesonide, but the latter has a dismal prognosis due to severe malnutrition and frequent progression to enteropathy-associated T-cell lymphoma; more efficient therapy is needed.

Predictors of Subsequent Celiac Disease Seropositivity in Patients Diagnosed with Duodenal Villus Atrophy on Upper Endoscopy

BACKGROUND

The diagnosis of celiac disease (CD) is based on positive IgA autoantibodies to tissue transglutaminase (TTG IgA) and confirmatory histopathology demonstrating duodenal villus atrophy (VA). Diagnostic challenges can occur when VA is found on duodenal biopsies in patients without prior CD serologies.

AIMS

To characterize the predictors of CD seropositivity in patients with VA on biopsy without prior CD serologies.

METHODS

We performed a retrospective cohort study of patients found to have duodenal VA on histopathology from 2010 to 2020 who did not have prior CD serologies measured and who had them checked after their biopsy. Patients with known or suspected CD prior to their duodenal biopsy were excluded.

RESULTS

Of 162 patients with VA and no prior CD serologies, 50 (31%) subsequently had an elevated TTG IgA consistent with CD. Patients with an elevated TTG IgA were more likely to be non-Hispanic (76% vs. 42%; p < 0.001), white (74% vs. 62%; p = 0.025), and younger (ages 18-39, 26% vs. 12%; p = 0.002) compared to those with a negative TTG IgA. By contrast, these patients were less likely to present in middle adulthood (ages 40-59, 6% vs. 29%; p =  0.002). The most common identified etiologies of seronegative VA were Crohn's disease (13%), seronegative CD (8.9%), H. pylori infection (6.3%), tropical sprue (5.4%), and olmesartan-related enteropathy (3.6%).

CONCLUSION

Age and ethnicity may be helpful when stratifying the likelihood of CD in the absence of supporting serologies. A majority of patients (69%) diagnosed with VA without prior CD serologies have negative serologies, consistent with seronegative CD or the spectrum of non-celiac enteropathies for which further evaluation is needed.

Refractory celiac disease and its mimickers: a review on pathogenesis, clinical-pathological features and therapeutic challenges

Refractory celiac disease (RCD) and enteropathy-associated T-cell lymphoma (EATL) are rare, yet severe complications of celiac disease (CD). Over the last decades, several studies have addressed the biology and clinical-pathological features of such conditions, highlighting unique disease patterns and recurrent genetic events. Current classification proposals identify two forms of RCD, namely: (i) type 1 RCD (RCD-I), characterized by phenotypically normal intra-epithelial lymphocytes (IELs); and (ii) type 2 RCD (RCD-II), featuring phenotypically aberrant IELs. While RCD-I likely represents a gluten-independent dysimmune reaction against small bowel epithelial cells, RCD-II is better considered an in situ aggressive T-cell lymphoma, with high rates of progression to overt EATL. The diagnosis of RCD and EATL is often challenging, due to misleading clinical-pathological features and to significant overlap with several CD-unrelated gastro-intestinal disorders. Similarly, the treatment of RCD and EATL is an unmet clinical need for both gastroenterologists and hematologists. Moving from such premises, this review aims to provide a comprehensive view of RCD and EATL, specifically considering their pathogenesis and the many still open issues concerning their diagnosis and clinical management.

Establishment of New Immunostatistical Equations for Diagnosis and Follow-Up of Gluten-Free Diet in Patients with Celiac Disease

<b>Background and Objective:</b> Celiac disease (CD) is an autoimmune condition characterized by immune responses to gluten. The reported prevalence of CD has increased globally due to improved screening and diagnostic techniques, however, there is significant global variation in methods of diagnosis and follow-up. A new immunostatistical equation that determines the values of two types of antibodies using the total IgA test. <b>Materials and Methods:</b> Only 70 blood samples were taken from people who had celiac disease or were suspected of having it, with ages ranging from 5 to 40 years and they were separated into two groups. The first group contained 40 people of both sexes who had previously been diagnosed with celiac disease, while the second group included 30 individuals of both sexes, with ages ranging from 5 to 35 years, who were suspected of having celiac disease due to the appearance of some clinical symptoms. The control group also included 30 blood samples from healthy individuals of both sexes, with ages ranging from 5 to 40 years. Total IgA antibody tTG/IgA and DGP/IgA levels were estimated for all study samples. <b>Results:</b> By using a regression coefficient test the results showed the percentage of the effect of total IgA on tTG/IgA, DGP/IgA amounted to 11 and 25%, respectively, as shown by the value of the coefficient of clarifications (R²) in patients with CD. On the other hand, The percentage of the effect of total IgA on tTG/IgA and DGP/IgA amounted to 11, 14%, respectively, as shown by the value of the coefficient of clarifications (R²) in patients with suspected CD in p<u><</u>0.05. The results of the study were revealed and through the regression coefficient, four new immunostatistical equations were mathematically derived that give the value of tTG/IgA and DGP/IgA based solely on the total IgA test in the laboratory. <b>Conclusion:</b> By adopting one laboratory test which determines total IgA, the study concluded four new immunostatistical equations that will help academic researchers and attending physicians to diagnose celiac disease in addition to following up on patient's adherence to a gluten-free diet.

AGA Clinical Practice Update on Management of Refractory Celiac Disease: Expert Review

DESCRIPTION

The purpose of this expert review is to summarize the diagnosis and management of refractory celiac disease. It will review evaluation of patients with celiac disease who have persistent or recurrent symptoms, differential diagnosis, nutritional support, potential therapeutic options, and surveillance for complications of this condition.

METHODS

This expert review was commissioned and approved by the American Gastroenterological Association (AGA) Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Gastroenterology. These Best Practice Advice (BPA) statements were drawn from a review of the published literature and from expert opinion. Since systematic reviews were not performed, these BPA statements do not carry formal ratings of the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: In patients believed to have celiac disease who have persistent or recurrent symptoms or signs, the initial diagnosis of celiac disease should be confirmed by review of prior diagnostic testing, including serologies, endoscopies, and histologic findings. BEST PRACTICE ADVICE 2: In patients with confirmed celiac disease with persistent or recurrent symptoms or signs (nonresponsive celiac disease), ongoing gluten ingestion should be excluded as a cause of these symptoms with serologic testing, dietitian review, and detection of immunogenic peptides in stool or urine. Esophagogastroduodenoscopy with small bowel biopsies should be performed to look for villous atrophy. If villous atrophy persists or the initial diagnosis of celiac disease was not confirmed, consider other causes of villous atrophy, including common variable immunodeficiency, autoimmune enteropathy, tropical sprue, and medication-induced enteropathy. BEST PRACTICE ADVICE 3: For patients with nonresponsive celiac disease, after exclusion of gluten ingestion, perform a systematic evaluation for other potential causes of symptoms, including functional bowel disorders, microscopic colitis, pancreatic insufficiency, inflammatory bowel disease, lactose or fructose intolerance, and small intestinal bacterial overgrowth. BEST PRACTICE ADVICE 4: Use flow cytometry, immunohistochemistry, and T-cell receptor rearrangement studies to distinguish between subtypes of refractory celiac disease and to exclude enteropathy-associated T-cell lymphoma. Type 1 refractory celiac disease is characterized by a normal intraepithelial lymphocyte population and type 2 is defined by the presence of an aberrant, clonal intraepithelial lymphocyte population. Consultation with an expert hematopathologist is necessary to interpret these studies. BEST PRACTICE ADVICE 5: Perform small bowel imaging with capsule endoscopy and computed tomography or magnetic resonance enterography to exclude enteropathy-associated T-cell lymphoma and ulcerative jejunoileitis at initial diagnosis of type 2 refractory celiac disease. BEST PRACTICE ADVICE 6: Complete a detailed nutritional assessment with investigation of micronutrient and macronutrient deficiencies in patients diagnosed with refractory celiac disease. Check albumin as an independent prognostic factor. BEST PRACTICE ADVICE 7: Correct deficiencies in macro- and micronutrients using oral supplements and/or enteral support. Consider parenteral nutrition for patients with severe malnutrition due to malabsorption. BEST PRACTICE ADVICE 8: Corticosteroids, most commonly open-capsule budesonide or, if unavailable, prednisone, are the medication of choice and should be used as first-line therapy in either type 1 or type 2 refractory celiac disease. BEST PRACTICE ADVICE 9: Patients with refractory celiac disease require regular follow-up by a multidisciplinary team, including gastroenterologists and dietitians, to assess clinical and histologic response to therapy. Identify local experts with expertise in celiac disease to assist with management. BEST PRACTICE ADVICE 10: Patients with refractory celiac disease without response to steroids may benefit from referral to a center with expertise for management or evaluation for inclusion in clinical trials.

Gut microbiome markers in subgroups of HLA class II genotyped infants signal future celiac disease in the general population: ABIS study

Although gut microbiome dysbiosis has been illustrated in celiac disease (CD), there are disagreements about what constitutes these microbial signatures and the timeline by which they precede diagnosis is largely unknown. The study of high-genetic-risk patients or those already with CD limits our knowledge of dysbiosis that may occur early in life in a generalized population. To explore early gut microbial imbalances correlated with future celiac disease (fCD), we analyzed the stool of 1478 infants aged one year, 26 of whom later acquired CD, with a mean age of diagnosis of 10.96 ± 5.6 years. With a novel iterative control-matching algorithm using the prospective general population cohort, All Babies In Southeast Sweden, we found nine core microbes with prevalence differences and seven differentially abundant bacteria between fCD infants and controls. The differences were validated using 100 separate, iterative permutations of matched controls, which suggests the bacterial signatures are significant in fCD even when accounting for the inherent variability in a general population. This work is the first to our knowledge to demonstrate that gut microbial differences in prevalence and abundance exist in infants aged one year up to 19 years before a diagnosis of CD in a general population.

The Value of Duodenal Biopsies in the Evaluation of Megaloblastic Anemia

Introduction Megaloblastic anemia is one of the common causes of anemia in India. Duodenal biopsies are routinely performed in the investigation of megaloblastic anemia. The present study was undertaken to analyze the value of duodenal biopsy in megaloblastic anemia and to correlate endoscopic findings with biopsy. As a secondary aim, the study has also analyzed the hematological profile and vitamin B ₁₂ and folate status of these patients.

Materials and Methods All the cases of megaloblastic anemia with bone marrow studies diagnosed at PSG Institute of Medical Sciences and Research during the two year period from January 2016 to December 2017 were retrieved. Clinical and laboratory findings (serum vitamin B ₁₂ and folate levels) and endoscopic findings were retrieved from hospital records of the patients. Duodenal biopsies of these patients reported in the histopathology department were retrieved and reviewed. Statistical analysis was done using SPSS software 20.0.

Results There were 93 cases of megaloblastic anemia diagnosed on bone marrow biopsies. Tropical sprue was diagnosed in 49.5% of cases, followed by intraepithelial lymphocytosis (17.2%), peptic duodenitis (17.2%), and no significant pathology in 16% of cases. Pancytopenia was present in 54.8% of cases. Isolated vitamin B ₁₂ deficiency including low levels was present in 48.38% and folate deficiency was seen in 4.3% cases; 34.48% cases had both vitamin B ₁₂ and folate deficiency.

Conclusion The incidence of tropical sprue in megaloblastic anemia is 49.5% in the study. Duodenal biopsy is valuable in the work up of megaloblastic anemia, irrespective of the endoscopic changes in identifying the etiology.

The Role of the Gluten-Free Diet in the Management of Seronegative Enteropathy

The differential diagnosis and treatment of seronegative enteropathy, also termed seronegative villous atrophy (SNVA), is a clinical challenge. Although seronegative coeliac disease (CD) is a frequent cause of SNVA, the aetiology can include immune-mediated, inflammatory, infectious, and drug-related forms. As a misdiagnosis of SNVA can result in patients being unnecessarily placed on a lifelong strict gluten-free diet or even given incorrect immunosuppressive therapy, the aim of this paper is to provide an evidence-based and practical approach for the workup and management of SNVA.

Approach to the adult patient with chronic diarrhea: A literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

Approach to the adult patient with chronic diarrhea: a literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

The Underlying Effects of Celiac Disease and Subsequent Implications on Deployment in the United States Army

INTRODUCTION

The purpose of this review is to provide an overview of the etiology, pathology, and treatments for celiac disease (CD), as well as to provide context as to how CD impacts the U.S. military.

MATERIALS AND METHODS

To conduct this review, the authors surveyed recent epidemiology and immunology literature in order to provide a detailed summary of the current understanding of CD, its diagnosis, and the real-world impacts within the Department of Defense (DoD).

RESULTS

We described the gluten proteins and both the immune response in CD. We further describe the underlying genetic risk factors and diagnosis and pathogenesis of the disease and conclude the review with a discussion of how current DoD regulations impact U.S. military readiness.

CONCLUSION

Celiac disease (CD) is an autoimmune disorder that results in damage to the small intestine. Ingestion of gluten in a CD patient is usually followed by villous atrophy in the small intestine, often along with other gastrointestinal symptoms. Around 1% of patients diagnosed with CD can experience complications if gluten-free diet is not followed, including intestinal lymphoma and hyposplenism. Therefore, a patient showing possible symptoms should discuss the diagnostic process with their healthcare providers to ensure adequate understanding of serological and genetic tests along with the histological examination of intestinal biopsy. Patients should seek consults with registered dietitians to structure their diets appropriately. Considering the prevalence and incidence of CD and gluten intolerances are increasing, the military should consider providing gluten-free Meals Ready-to-Eat as an option for all service members. Given the retention of service members with CD, subsequent admission of personnel with mild CD that does not affect the duties will allow the DoD access to a growing population of fully capable service members with critical technical skills who are eager to serve the USA.

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

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

Celiac Disease: Updates on Pathology and Differential Diagnosis

Celiac disease is a gluten-triggered immune-mediated disorder, characterized by inflammation of the enteric mucosa following lymphocytic infiltration and eventually resulting in villous blunting. There have been many developments in refining diagnostic laboratory tests for celiac disease in the last decade. Biopsy-sparing diagnostic guidelines have been proposed and validated in a few recent prospective studies. However, despite these developments, histologic evaluation of duodenal mucosa remains one of the most essential diagnostic tools as it helps in the diagnosis of celiac disease in individuals who do not fulfill the biopsy-sparing diagnostic criteria and in those not responding to a gluten-free diet. Histologic evaluation also allows for the assessment of mucosal recovery after treatment and in the identification of concurrent intestinal diseases. Therefore, pathologists should be familiar with the histologic spectrum of celiac disease and need to be aware of other disorders with similar symptoms and histopathology that may mimic celiac disease. This review aims to provide pathologists with updates on celiac laboratory testing, biopsy-sparing diagnostic criteria, histopathology, complications, and differential diagnoses of celiac disease.

Enterotoxigenic Escherichia coli Infections

PURPOSE OF REVIEW

Review recent developments pertaining to the epidemiology, molecular pathogenesis, and sequelae of enterotoxigenic Escherichia coli (ETEC) infections in addition to discussion of challenges for vaccinology.

RECENT FINDINGS

ETEC are a major cause of diarrheal illness in resource poor areas of the world where they contribute to unacceptable morbidity and continued mortality particularly among young children; yet, precise epidemiologic estimates of their contribution to death and chronic disease have been difficult to obtain. Although most pathogenesis studies, and consequently vaccine development have focused intensively on canonical antigens, more recently identified molecules unique to the ETEC pathovar may inform our understanding of ETEC virulence, and the approach to broadly protective vaccines. ETEC undeniably continue to have a substantial impact on global health; however, further studies are needed to clarify the true impact of these infections, particularly in regions where access to care may be limited. Likewise, our present understanding of the relationship of ETEC infection to non-diarrheal sequelae is presently limited, and additional effort will be required to achieve a mechanistic understanding of these diseases and to fulfill Koch's postulates on a molecular level. Precise elucidation of the role played by novel virulence factors, the global burden of acute illness, and the contribution of these pathogens and/or their toxins to non-diarrheal morbidity remain important imperatives.