Adult autoimmune enteropathy: Mayo Clinic Rochester experience

Comprehensive insights into pathogenesis, diagnosis, treatment, and prognosis in adult autoimmune enteropathy

Autoimmune enteropathy (AIE) constitutes a diverse array of disorders characterized by immune dysregulation and gastrointestinal manifestations, chiefly chronic diarrhea. Due to the small number of reported cohorts, the current knowledge and understanding of adult-onset AIE is rare compared with pediatric or syndromic AIE. Pathogenesis might involve genetic predisposition, aberrant immune homeostasis, comorbidities of autoimmune diseases and environmental trigger. Diagnosis relies on a comprehensive assessment encompassing clinical evaluation, laboratory tests, endoscopic findings and histopathological features, yet distinguishing AIE from other disorders with similar presentations poses diagnostic challenges. Treatment strategies predominantly center on immunosuppressive therapies, exhibiting varied efficacy among individuals. Supportive treatment and prevention and management of complications are also important for prognosis. The prospectives of future researches need to explore the genetic and immunological mechanism, the diagnostic modalities and the treatment strategies to improve patient outcomes.

Intestinal failure from thymoma-associated autoimmune enteropathy: a rare case report

We describe a case of altered bowel habit, early satiety, anorexia and weight loss caused by autoimmune enteropathy. This diagnosis was confirmed by biopsies obtained from upper gastrointestinal endoscopy and ileocolonoscopy. Further investigations revealed multiple pulmonary nodules which were metastases from a malignant thymoma. The patient was commenced on oral budesonide and Mesalazine, in addition to oral and enteral supplementation driven by the specialist nutrition support team, but she did not achieve histological remission, nor did she demonstrate improvement in her nutritional status. She received 3-weeks of in-patient parenteral nutrition, but then subsequently deteriorated as she declined home parenteral nutrition. The patient died eight months later from complications of her disease. This case highlights the rare manifestation of metastatic thymoma presenting with autoimmune enteropathy that led to intestinal failure and death.

Non-celiac Enteropathies

PURPOSE OF REVIEW

Non-celiac enteropathies (NCE) can be due to a variety of causes. The workup for NCE includes history, physical, laboratory and histology review and can be difficult. Enteropathies can result in serious illness due to consequences of malabsorption including severe weight loss, nutritional deficiencies, and debilitating diarrhea. Recognition and support of these consequences while investigating underlying etiology is essential.

RECENT FINDINGS

Recent studies in NCEs have focused on improving diagnostic accuracy and predicting long-term outcomes in patients with NCEs. Further, literature has emphasized the importance of histological analysis, with a focus on differentiating between various enteropathies that cause villous atrophy, highlighting the complexity and need for personalized approaches in managing these conditions. Identification of etiologies of NCEs requires review of patients' detailed history, medications, and lab results. Common etiologies include immunodeficiencies, infectious, iatrogenic, and malignant causes. Using a systematic approach can lead to proper diagnosis and tailor treatment choices, benefiting patient outcomes. Supportive nutrition care should be initiated early when applicable to minimize morbidity.

Long-term Prognosis of Nonceliac Enteropathies and a Score to Identify Patients With Poor Outcomes: A 30-year Multicenter Longitudinal Study

INTRODUCTION

Long-term prognosis of nonceliac enteropathies (NCEs) is poorly understood. We aimed to evaluate long-term outcomes and develop a prognostic score for NCEs.

METHODS

NCEs patients from an international multicenter cohort (4 Italian centers, 1 United Kingdom, 1 French, 1 Norwegian, 1 United States, 1 Indian) followed-up over 30 years were enrolled. Complications and mortality were analyzed with Kaplan-Meier curves, standardized mortality ratios (SMR), and multivariate Cox regression. A clinical score to identify patients at risk of poor outcomes was developed.

RESULTS

Two hundred sixty-one patients were enrolled (144 female, mean age at diagnosis 49 ± 18 years, median follow-up 70 months, interquartile range 24-109). The most common etiologies were idiopathic villous atrophy (39%), drug related (17%), common variable immune deficiency (15%), infectious (10%), and autoimmune enteropathy (9%). Five-year and 10-year complication-free survival were 89% and 77%, respectively, whereas 5-year and 10-year overall survival were 88% and 74%, respectively. Causes of death included sepsis/major infections (22%), lymphoproliferative disorders (22%), solid-organ malignancies (12%), cardiovascular/metabolic disease (10%), and was unknown in 33%. Mortality was increased in NCEs compared with the general population (SMR 3.17, 95% confidence interval [CI] 2.24-4.34). Older age at diagnosis ( P < 0.001), anemia (hazard ratio [HR] 2.53, 95% CI 1.33-4.80, P < 0.01), and lack of clinical (HR 3.21, 95% CI 1.68-6.18, P < 0.01) and histological response (HR 2.14, 95% CI 1.08-4.23, P = 0.04) were independent predictors of mortality at Cox regression. A 5-point score was developed to identify high-risk patients: very low risk (0 pts), low risk (1-2 pts), intermediate risk (3 pts), and high risk (4-5 pts), with 10-year survival rates of 100%, 87%, 62%, and 16%, respectively.

DISCUSSION

Mortality in NCEs is increased because of complications and lack of response to current therapies. We developed a clinical score to personalize follow-up. Targeted treatments are needed to improve outcomes.

A Rare Case of Autoimmune Enteropathy After Thymectomy

Autoimmune enteropathy (AIE) is a rare cause of chronic diarrhea associated with autoantibodies and susceptibility to other autoimmune diseases, such as rheumatoid arthritis, diabetes, autoimmune hemolytic anemia, and atopic dermatitis. While it is more common in children, the prevalence of AIE in adults is increasing. Due to the nonspecific nature of its presenting symptoms and the lack of consistent findings, AIE can be challenging to diagnose. Here, we present a 66-year-old male patient who presented to the emergency department with diarrhea and recurrent bilateral pleural effusions two months after thymoma resection and was eventually diagnosed with AIE. The evaluation revealed blunting of small intestinal villi on biopsy, an IgG staining pattern indicative of circulating anti-enterocyte antibodies, as well as the presence of serum anti-enterocyte and anti-goblet cell antibodies, establishing the diagnosis of AIE.

Adult-Onset Autoimmune Enteropathy Mimicking Disaccharidase Deficiency

Adult-onset autoimmune enteropathy is a rare disorder characterized by severe diarrhea, weight loss, malnutrition, and enteric mucosal atrophy resulting from immune-mediated injury. Disaccharidase deficiencies are a group of disorders characterized by inadequate activity of disaccharidase in the small intestine, leading to impaired digestion of disaccharides and malabsorption. Here, we present a case of adult-onset autoimmune enteropathy initially diagnosed as disaccharidase deficiency based on the clinical symptoms of chronic diarrhea, weight loss, and severely reduced levels of lactase, maltase, palatinase, and sucrase in duodenal aspirates. However, follow-up duodenal biopsy revealed markedly villous blunting, goblet and Paneth cell depletion, increased crypt apoptotic bodies and lamina propria lymphoplasmacytic inflammation, leading to a revised diagnosis of autoimmune enteropathy. This case highlights the diagnostic challenges of adult-onset autoimmune enteropathy and the importance of considering it in adults with unexplained gastrointestinal symptoms. It also emphasizes the need for tissue biopsies in cases with inconclusive initial diagnostic tests. Increased awareness of these disorders and their mimickers can improve diagnosis and management, ultimately benefiting patients with these conditions.

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.

Clinical manifestations, diagnosis and long-term prognosis of adult autoimmune enteropathy: Experience from Peking Union Medical College Hospital

BACKGROUND

Autoimmune enteropathy (AIE) is a rare disease whose diagnosis and long-term prognosis remain challenging, especially for adult AIE patients.

AIM

To improve overall understanding of this disease's diagnosis and prognosis.

METHODS

We retrospectively analyzed the clinical, endoscopic and histopathological characteristics and prognoses of 16 adult AIE patients in our tertiary medical center between 2011 and 2023, whose diagnosis was based on the 2007 diagnostic criteria.

RESULTS

Diarrhea in AIE patients was characterized by secretory diarrhea. The common endoscopic manifestations were edema, villous blunting and mucosal hyperemia in the duodenum and ileum. Villous blunting (100%), deep crypt lymphocytic infiltration (67%), apoptotic bodies (50%), and mild intraepithelial lymphocytosis (69%) were observed in the duodenal biopsies. Moreover, there were other remarkable abnormalities, including reduced or absent goblet cells (duodenum 94%, ileum 62%), reduced or absent Paneth cells (duodenum 94%, ileum 69%) and neutrophil infiltration (duodenum 100%, ileum 69%). Our patients also fulfilled the 2018 diagnostic criteria but did not match the 2022 diagnostic criteria due to undetectable anti-enterocyte antibodies. All patients received glucocorticoid therapy as the initial medication, of which 14/16 patients achieved a clinical response in 5 (IQR: 3-20) days. Immunosuppressants were administered to 9 patients with indications of steroid dependence (6/9), steroid refractory status (2/9), or intensified maintenance medication (1/9). During the median of 20.5 months of follow-up, 2 patients died from multiple organ failure, and 1 was diagnosed with non-Hodgkin's lymphoma. The cumulative relapse-free survival rates were 62.5%, 55.6% and 37.0% at 6 months, 12 months and 48 months, respectively.

CONCLUSION

Certain histopathological findings, including a decrease or disappearance of goblet and Paneth cells in intestinal biopsies, might be potential diagnostic criteria for adult AIE. The long-term prognosis is still unsatisfactory despite corticosteroid and immunosuppressant medications, which highlights the need for early diagnosis and novel medications.

Intractable diarrhea in an infant-autoimmune enteropathy: A case report

Autoimmune enteropathy is a rare cause of chronic intractable diarrhea and is present in <1 in 100,000 infants. We report the case of a 9-month-old boy who presented with intractable diarrhea and vomiting. Genetic panel testing revealed a STAT3 heterozygous mutation in exon 6, suggesting infantile-onset multisystem autoimmune disease-1. The patient was initially treated with steroids and sulfasalazine. However, on tapering steroids, he had another episode of diarrhea and was subsequently put on baricitinib to which he responded.

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.

Autoimmune enteropathy complicated with primary biliary cholangitis

Autoimmune enteropathy is a rare intestinal disease. Here we report an elderly female with autoimmune enteropathy and primary biliary cholangitis who presented with chronic diarrhea, malnutrition and severe hypokalemia and metabolic acidosis. Enteroscopy showed atrophied small intestinal villi with scallop-like and fissure-like changes. Hormone treatment relieved diarrhea. Four months later, she developed primary biliary cholangitis, and the liver function returned to normal after treatment with ursodeoxycholic acid, corticosteroids and immunosuppressants.

Localised intestinal Kaposi sarcoma in a patient with non-coeliac seronegative villous atrophy

Seronegative villous atrophy (SNVA) is a diagnostic challenge for gastroenterologists, which is defined by villous atrophy and negative coeliac serology. Non-coeliac forms of SNVA, such as autoimmune enteropathy, can be life-threatening leading to intractable diarrhoea and severe malabsorption that require systemic immunosuppression. When all known causes have been excluded, it is termed idiopathic villous atrophy (IVA). We present a case of non-coeliac SNVA complicated by Kaposi sarcoma (KS). A previously well HIV-negative man in his 30s presented with a 4-month history of watery diarrhoea and 25 kg weight loss. After prolonged investigation, he was diagnosed with non-coeliac SNVA without an identified aetiology that would be consistent with IVA. Clinical recovery was achieved with parenteral nutrition for type II intestinal failure and immunosuppression using high-dose corticosteroids. On subsequent gastroscopy, he was diagnosed with localised intestinal KS prompting cessation of all immunosuppression but remained in clinical remission.

APECED and the place of AIRE in the puzzle of the immune network associated with autoimmunity

In the last 20 years, discoveries about the autoimmune regulator (AIRE) protein and its critical role in immune tolerance have provided fundamental insights into understanding the molecular basis of autoimmunity. This review provides a comprehensive overview of the effect of AIRE on immunological tolerance and the characteristics of autoimmune diseases in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED), which is caused by biallelic AIRE mutations. A better understanding of the immunological mechanisms of AIRE deficiency may enlighten immune tolerance mechanisms and new diagnostic and treatment strategies for autoimmune diseases. Considering that not all clinical features of APECED are present in a given follow-up period, the diagnosis is not easy in a patient at the first visit. Longer follow-up and a multidisciplinary approach are essential for diagnosis. It is challenging to prevent endocrine and other organ damage compared with other diseases associated with multiple autoimmunities, such as FOXP3, LRBA, and CTLA4 deficiencies. Unfortunately, no curative therapy like haematopoietic stem cell transplantation or specific immunomodulation is present that is successful in the treatment.

A Combination Therapy in a Rare Case of Adult-Onset Autoimmune Enteropathy

Autoimmune enteropathy (AIE) is a differential diagnosis of incurable chronic diarrhea, malnutrition, and weight loss. This type of diarrhea is associated with protein enteropathy that usually affects the small intestine. The diagnosis of AIE is based on chronic diarrhea, malabsorption, specific histological result, antibodies against enterocytes, and excluding similar conditions. In this case, a 28-year-old female presented with diarrhea, lower limb edema, weight loss, and electrolyte imbalances. Endoscopic examination demonstrated duodenal villous atrophy, while duodenal biopsies revealed villous blunting, scattered intraepithelial lymphocytes, and crypt hyperplasia in the lamina propria. The patient was treated with immunosuppressive treatment including methylprednisolone and azathioprine, achieving clinical remission.

Adult-Onset Autoimmune Enteropathy: A Case Report

Small bowel villous atrophy is most often caused by celiac disease in the Western world, but other diseases should be explored in patients without positive serology. Adult-onset autoimmune enteropathy (AIE) is a rare cause of villous atrophy first known in children with T-cell dysregulation but also seen in adults with autoimmune predispositions. Here, an 82-year-old woman with autoimmune thyroiditis was admitted with weight loss and watery diarrhoea not responding to diet change. Endoscopy revealed villous atrophy both in the duodenum and in the ileum, but no positive celiac serology. A diagnosis of autoimmune enteropathy was made based on chronic diarrhoea not responding to diet change, autoimmune predisposition, villous atrophy, typical histological findings, and no evidence of immunodeficiency or medications causing villous atrophy. The patient was treated to good effect with corticosteroids but needed total parenteral nutrition while admitted. AIE should be considered in villous atrophy without positive celiac serology.

Autoimmune Enteropathy: A Rare Cause of Chronic Diarrhea in an Adult Patient

Autoimmune enteropathy is a rare cause of malabsorption usually associated with circulating autoantibodies and predisposition to autoimmune disorders. The diagnosis is based on the following criteria: chronic diarrhea (>6 months), malabsorption, specific histological findings, anti-enterocyte and anti-goblet cell antibodies, and exclusion of similar disorders. We report a case of a 73-year-old woman presenting with severe chronic diarrhea, weight loss, and electrolyte abnormalities. Endoscopy revealed duodenal villous atrophy extending to proximal jejunum, and duodenal biopsies revealed villous blunting, cryptitis with apoptosis, and scattered intraepithelial lymphocytes. Therapeutic management included immunosuppressive treatment with corticosteroids, achieving clinical remission.

Beyond IBD: the genetics of other early-onset diarrhoeal disorders

Diarrhoeal disorders in childhood extend beyond the inflammatory bowel diseases. Persistent and severe forms of diarrhoea can occur from birth and are associated with significant morbidity and mortality. These disorders can affect not only the gastrointestinal tract but frequently have extraintestinal manifestations, immunodeficiencies and endocrinopathies. Genomic analysis has advanced our understanding of these conditions and has revealed precision-based treatment options such as potentially curative haematopoietic stem cell transplant. Although many new mutations have been discovered, there is frequently no clear genotype-phenotype correlation. The functional effects of gene mutations can be studied in model systems such as patient-derived organoids. This allows us to further characterise these disorders and advance our understanding of the pathophysiology of the intestinal mucosa. In this review, we will provide an up to date overview of genes involved in diarrhoeal disorders of early onset, particularly focussing on the more recently described gene defects associated with protein loosing enteropathy.

Drug-induced digestive tract injury: decoding some invisible offenders

There is an ever-growing list of pharmacological agents, several of which are attributed to cause clinically significant gastrointestinal (GI) injury. Many patients present with significant but nonspecific symptoms, that in conjunction with the absence of relevant drug history on the requisition slip can make the histopathologic diagnosis challenging. To complicate this, although some drugs have relatively characteristic histopathologic features (such as doxycycline), there exist many other drugs that exhibit wide and varying spectra of histopathologic findings (such as immune checkpoint inhibitors or olmesartan) and have histomorphologic overlap with many other commonly encountered disease entities. This review discusses the histopathologic features of some relatively recently described drugs causing GI tract injury, namely doxycycline, tacrolimus, mycophenolate, immune checkpoint inhibitors, and olmesartan. We also discuss the common mimics in histopathologic differential and some pearls that can help distinguish GI tract injury induced by the aforementioned drugs from its mimics. Awareness of the wide spectra of histopathologic changes associated with these drugs is crucial for practicing pathologists, to avoid misdiagnosis and guiding the clinician for an optimal patient management, which usually involves modifying or discontinuing the offending drug. Needless to say, once a diagnosis of drug-induced injury is suspected, clinicopathologic correlation including corroboration with the drug history is of utmost importance as is the exclusion of dual pathology in these patients.

DQA1*0102 DQB1*0602 haplotype distinguishes coeliac disease and its complications from gluten unrelated enteropathies

BACKGROUND

Duodenal villous atrophy is due not only to coeliac disease and its complications but also to other rare enteropathies unrelated to gluten consumption, defined as noncoeliac enteropathies. The diagnosis of noncoeliac enteropathies remains challenging, and HLA typing has been widely used to exclude coeliac disease if DQ2 and DQ8 alleles are absent. However, the frequency of the various HLA alleles in noncoeliac enteropathies is still unknown.

AIMS

To describe the HLA genetic profile of patients affected by noncoeliac enteropathies who have been evaluated at our centres between 2000 and 2021, and to investigate the diagnostic role of HLA typing.

METHODS

Genomic DNA was collected from 44 Italian and 19 British adult patients with noncoeliac enteropathies. Patient genotypes were compared with those of healthy Italian and British populations obtained from HLA bone marrow donors' banks. In addition, genotypes were also compared with those of patients with coeliac disease and complicated coeliac disease.

RESULTS

Both in the Italian and in the British group, the DQA1*0102 DQB1*0602 haplotype and related alleles occurred significantly more frequently in patients with noncoeliac enteropathies compared to coeliac disease and complicated coeliac disease.

CONCLUSIONS

Together with negative HLA-DQ2 and DQ8 haplotypes, the DQA1*0102 DQB1*0602 haplotype can be used to guide the differential diagnosis between coeliac disease and noncoeliac enteropathies.

Nomenclature and diagnosis of seronegative coeliac disease and chronic non-coeliac enteropathies in adults: the Paris consensus

OBJECTIVE

Differential diagnosis of villous atrophy (VA) without coeliac antibodies in adults includes seronegative coeliac disease (CD) and chronic enteropathies unrelated to gluten, ie. non-coeliac enteropathies (NCEs). There is currently no international consensus on the nomenclature and diagnostic criteria for these enteropathies. In this work, a Delphi process was conducted to address this diagnostic and clinical uncertainty.

DESIGN

An international task force of 13 gastroenterologists from six countries was recruited at the 16th International Coeliac Disease Symposium, Paris, 2019. Between September 2019 and July 2021, a Delphi process was conducted through mail surveys to reach a consensus on which conditions to consider in the differential diagnosis of VA with negative coeliac serology and the clinical diagnostic approaches required for these conditions. A 70% agreement threshold was adopted.

RESULTS

Chronic enteropathies characterised by VA and negative coeliac serology can be attributed to two main clinical scenarios: forms of CD presenting with negative serology, which also include seronegative CD and CD associated with IgA deficiency, and NCEs, with the latter recognising different underlying aetiologies. A consensus was reached on the diagnostic criteria for NCEs assisting clinicians in differentiating NCEs from seronegative CD. Although in adults seronegative CD is the most common aetiology in patients with VA and negative serology, discriminating between seronegative CD and NCEs is key to avoid unnecessary lifelong gluten-free diet, treat disease-specific morbidity and contrast poor long-term outcomes.

CONCLUSION

This paper describes the Paris consensus on the definitions and diagnostic criteria for seronegative CD and chronic NCEs in adults.

Refactory Coeliac disease-a case series from Pakistan

Coeliac disease or gluten intolerance is a frequent cause of chronic diarrhoea leading to malabsorptive symptoms. Refractory coeliac disease is a rare entity, which is not only harder to diagnose but managing it can be challenging. We hereby present three such cases.

ECCO Topical Review on Clinicopathological Spectrum and Differential Diagnosis of Inflammatory Bowel Disease

INTRODUCTION

Many diseases can imitate inflammatory bowel disease [IBD] clinically and pathologically. This review outlines the differential diagnosis of IBD and discusses morphological pointers and ancillary techniques that assist with the distinction between IBD and its mimics.

METHODS

European Crohn's and Colitis Organisation [ECCO] Topical Reviews are the result of an expert consensus. For this review, ECCO announced an open call to its members and formed three working groups [WGs] to study clinical aspects, pathological considerations, and the value of ancillary techniques. All WGs performed a systematic literature search.

RESULTS

Each WG produced a draft text and drew up provisional Current Practice Position [CPP] statements that highlighted the most important conclusions. Discussions and a preliminary voting round took place, with subsequent revision of CPP statements and text and a further meeting to agree on final statements.

CONCLUSIONS

Clinicians and pathologists encounter a wide variety of mimics of IBD, including infection, drug-induced disease, vascular disorders, diverticular disease, diversion proctocolitis, radiation damage, and immune disorders. Reliable distinction requires a multidisciplinary approach.

Autoimmune Diseases of Digestive Organs-A Multidisciplinary Challenge: A Focus on Hepatopancreatobiliary Manifestation

It is well known that some pathological conditions, especially of autoimmune etiology, are associated with the HLA (human leukocyte antigen) phenotype. Among these diseases, we include celiac disease, inflammatory bowel disease, autoimmune enteropathy, autoimmune hepatitis, primary sclerosing cholangitis and primary biliary cholangitis. Immunoglobulin G4-related diseases (IgG4-related diseases) constitute a second group of autoimmune gastrointestinal, hepatobiliary and pancreatic illnesses. IgG4-related diseases are systemic and rare autoimmune illnesses. They often are connected with chronic inflammation and fibrotic reaction that can occur in any organ of the body. The most typical feature of these diseases is a mononuclear infiltrate with IgG4-positive plasma cells and self-sustaining inflammatory response. In this review, we focus especially upon the hepatopancreatobiliary system, autoimmune pancreatitis and IgG4-related sclerosing cholangitis. The cooperation of the gastroenterologist, radiologist, surgeon and histopathologist is crucial for establishing correct diagnoses and appropriate treatment, especially in IgG4 hepatopancreatobiliary diseases.

Enteropathies with villous atrophy but negative coeliac serology in adults: current issues

Objective

The differential diagnosis and management of seronegative enteropathies is challenging due to the rarity of these conditions, the overlap of clinical and histopathological features and the current lack of an international consensus on their nomenclature.

Design

This is a narrative review providing pragmatic guide on the investigation and clinical management of seronegative enteropathies in adults based on the available literature and our clinical experience.

Conclusions

Seronegative coeliac disease is the most frequent cause among the heterogeneous group of seronegative enteropathies and its diagnosis is confirmed by the clinical and histological response to a gluten-free diet after the exclusion of other causes of villous atrophy. Correct identification and targeted management of seronegative enteropathies is mandatory because of the variation in terms of clinical outcomes and prognosis.

Clinical Features and Therapeutic Outcomes of Post-colectomy Enteritis with Ulcerative Colitis

Objectives

Few reports are available on post-colectomy enteritis (PCE) with ulcerative colitis (UC), which can be severe and sometimes fatal. The clinical characteristics are unclear, and treatment and diagnosis protocols have not been established. We aimed to investigate the incidence, clinical characteristics, diagnostic criteria, and therapeutic outcomes of PCE in this study.

Methods

Patients with UC who underwent colectomy between April 2010 and December 2019 were included in this study. We retrospectively analyzed patients who developed PCE and excluded patients with other forms of enteritis.

Results

We performed 829 colectomies because of a preoperative diagnosis of UC. Eleven and four patients were diagnosed with Crohn's disease and indeterminate colitis after surgery, respectively; 22 patients developed enteritis in the perioperative period. We excluded six patients with backwash ileitis, five with prepouch ileitis, three with infectious enteritis, and one with ischemic enteritis. In total, 7/814 (0.8%) patients developed PCE. All patients with PCE had pancolitis. PCE was observed a median of 33 (12-248) days after surgery. Endoscopy showed friable and granular mucosa. The extent of disease included various types such as pan-enteritis with diffuse type, pan-enteritis and mild inflammation in the middle ileum, and only ileitis. Gastroduodenitis-associated UC developed in 6/7 cases. All patients improved with tumor necrosis factor alpha (TNFα) antagonists even if TNFα antagonists had not been effective for colitis.

Conclusions

PCE was rare. The mucosal endoscopic findings were similar to those of UC, and the extent of disease varied. TNFα antagonist administration for PCE was effective.

Thymoma-associated autoimmune enteropathy with colonic stricture: a diagnostic and histological challenge

Thymoma-associated autoimmune enteropathy is a rare paraneoplastic syndrome that is characterized by severe chronic diarrhea, malabsorption, and specific histological findings. Because of its rarity, it is difficult to diagnose. We describe an adult patient with protracted diarrhea and weight loss that developed recurrent sepsis and progressive colonic stenosis due to thymoma-associated autoimmune enteropathy. Ultimately, the diagnosis thymoma-associated autoimmune enteropathy was established by characteristic intestinal histology, anti-enterocytes antibodies, and thorax imaging. Radical thymectomy was performed without improvement. Therapy with azathioprine and infliximab induced clinical remission with complete recovery of the colonic stenosis.

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

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

Adult-Onset Autoimmune Enteropathy in an European Tertiary Referral Center

INTRODUCTION

Adult-onset autoimmune enteropathy (AIE) is a rare cause of severe chronic diarrhea because of small intestinal villous atrophy. We report on patients with adult-onset AIE in an European referral center.

METHODS

Retrospective study including patients diagnosed with AIE in the Amsterdam UMC, location VUmc, between January 2003 and December 2019. Clinical, serological, and histological features and response to treatment were reported. The specificity of antienterocyte antibodies (AEA) was evaluated by examining the prevalence of AEA in (i) controls (n = 30) and in patients with (ii) AIE (n = 13), (iii) celiac disease (CD, n = 52), (iv) refractory celiac disease type 2 (n = 18), and (v) enteropathy-associated T-cell lymphoma (EATL, n = 10).

RESULTS

Thirteen AIE patients were included, 8 women (62%), median age of 52 years (range 23-73), and 6 (46%) with an autoimmune disease. AEA were observed in 11 cases (85%), but were also found in CD (7.7%), refractory celiac disease type 2 (16.7%), and EATL (20%). Ten patients (77%) were human leukocyte antigen DQ2.5 heterozygous. Total parenteral nutrition was required in 8 cases (62%). Steroids induced clinical remission in 8 cases (62%). Step-up therapy with rituximab, cyclosporine, infliximab, and cladribine in steroid-refractory patients was only moderately effective. Four patients died (31%), but 4 (31%) others are in long-term drug-free remission after receiving immunosuppressive treatment, including 1 patient who underwent autologous stem cell transplantation.

DISCUSSION

Adult-onset AIE is a rare but severe enteropathy that occurs in patients susceptible for autoimmune disease. Four patients (31%) died secondary to therapy-refractory malabsorption, while immunosuppressive therapy leads to a long-lasting drug-free remission in one-third of patients.

Histopathology of non-IBD colitis practical recommendations from pathologists of IG-IBD Group

Pathologists are often called upon to diagnose colitides that differ from the two main forms of inflammatory bowel disease (IBD). These non-IBD colitides include infectious colitis, microscopic colitis, ischemic colitis, eosinophilic colitis, autoimmune enterocolitis, segmental colitis associated with diverticulosis, drug-induced colitis, radiation colitis and diversion colitis. The diagnosis of these different disease entities relies on the histopathological examination of endoscopic biopsies of the gastrointestinal tract. This paper reviews the main histomorphological characteristics of the various Non-IBD colitides.

Diagnostic and therapeutic challenge of unclassifiable enteropathies with increased intraepithelial CD103+ CD8+ T lymphocytes: a single center case series

OBJECTIVES

Chronic diarrhea, villous atrophy and/or increased intraepithelial T-lymphocytes (IEL) occur in many inflammatory disorders including celiac disease (CD). However, a definite diagnosis is difficult to make in some patients despite an extensive diagnostic work-up. Clinical outcomes and histological phenotypes of such patients we refer to as unclassifiable enteropathy (UEP) remain unclear.

MATERIAL AND METHODS

We performed a retrospective single-center analysis of patients with chronic diarrhea, weight loss and increased IEL. Patients with defined etiologies including infections, CD, drugs, immunodeficiencies or neoplasms were excluded. Clinical and histologic/immunophenotypic parameters were analyzed.

RESULTS

Nine patients with UEP were identified. Small intestinal damage ranged from minor villous abnormalities to complete atrophy while all patients displayed high numbers of CD103+ CD8+ IELs. In contrast to CD, these CD8+ T cells were not confined to the surface epithelium, but also infiltrated the crypts. Additional histological features included apoptotic crypt epithelial cells and mixed inflammatory infiltrates in the tunica propria. Involvement of other segments of the gastrointestinal tract was observed in 7/9 patients. A clonal intestinal T-cell lymphoproliferative disorder developed in 2 patients, one of which had a fatal disease course. The majority of patients responded to corticosteroids, while response to immunosuppressive medications yielded heterogeneous results.

CONCLUSIONS

We report a patient population with 'difficult-to-classify' enteropathies characterized by various degrees of villous atrophy and strongly increased intraepithelial CD103+ CD8+ T cells in the small intestine which harbor an increased risk for T-cell lymphoproliferative disorders. Clinical course, histology, and response to immunosuppressive therapy all suggest an autoimmune pathogenesis.

Clinical guidelines “Chronic diarrhea in adults”

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Endoscopic Evaluation and Therapeutic Considerations of Small Bowel Crohn’s Disease

Small bowel evaluation is warranted in all newly diagnosed cases of Crohn’s disease (CD) as small bowel is involved in two-thirds of CD patients at diagnosis and the involvement can be discontinuous. Endoscopic evaluation of the small bowel in suspected or established CD can be done by video capsule endoscopy (VCE), device assisted enteroscopy (DAE) (which includes single and double balloon enteroscopy, novel motorized spiral enteroscopy (NMSE) and balloon guided endoscopy (BGE)) and intra-operative enteroscopy (IOE). In suspected CD with a negative ileo-colonoscopy, VCE is the preferred initial diagnostic modality in the absence of obstructive symptoms or known stenosis. VCE should be preceded by cross-sectional imaging or patency capsule testing if obstruction is suspected given with high retention risk. In established cases, small bowel cross-sectional imaging (magnetic resonance or computed tomography enterography) is preferred over VCE as it can assess transmural and extra-luminal involvement. VCE is indicated subsequently if necessary to assess disease extent, unexplained symptoms (e.g., anemia, malnutrition) or mucosal healing. Pan-enteric capsule endoscopy (PCE) and the use of artificial intelligence are the recent developments with VCE. DAE with small bowel biopsy can provide definitive evidence of CD including the extent and severity. A final diagnosis of CD is based on the constellation of clinical, radiologic, histologic and endoscopic features. Newer technologies like NMSE and BGE can help with deeper and faster small bowel evaluation. DAE has also allowed endoscopic treatment of small bowel strictures, small bowel bleeding and retrieval of retained capsule or foreign bodies. Endoscopic balloon dilation (EBD), endoscopic electro-incision, strictureplasty and stenting have shown promising results in CD related small bowel strictures. In conclusion, endoscopic evaluation of the small bowel is rapidly evolving field that has a major role in diagnosis and management of small bowel CD and can alter treatment outcomes in properly selected patients.

Adult autoimmune enteropathy in autoimmune hepatitis patient. Case report and literature review

Autoimmune enteropathy (AIE) is a rare disease characterized by prolonged diarrhea, vomiting and weight loss; although it is mainly a rare pediatric disease, over the years a number of adults have also been found to be affected. In this study, we present a case report of a 73-year-old woman with a history of autoimmune hepatitis, antinuclear (ANA) and positive anti-enterocyte antibodies (AEA), who has suffered two months of intractable diarrhea, nausea, anorexia and severe weight loss. The histological examination of the endoscopic duodenal mucosa biopsies revealed severe shortening and flattening of the villi, resulting in mucosal atrophy. The immunohistochemical study revealed a polymorphic lymphoid population, exhibiting a B cell (CD20+) phenotype in follicles and a T cell phenotype (CD3+) in the diffuse component within the lamina propria. Our patient had a complete recovery after two weeks of taking prednisone and following a gluten-rich diet. To our knowledge this is the first case of autoimmune enteropathy in adults with ANA and AEA 7 years after a diagnosis of autoimmune hepatitis. To date, the patient is still in clinical remission on a low dose of orally administered predinisone without any additional immunosuppression.

Small and Large Intestine (I): Malabsorption of Nutrients

Numerous disorders can alter the physiological mechanisms that guarantee proper digestion and absorption of nutrients (macro- and micronutrients), leading to a wide variety of symptoms and nutritional consequences. Malabsorption can be caused by many diseases of the small intestine, as well as by diseases of the pancreas, liver, biliary tract, and stomach. This article provides an overview of pathophysiologic mechanisms that lead to symptoms or complications of maldigestion (defined as the defective intraluminal hydrolysis of nutrients) or malabsorption (defined as defective mucosal absorption), as well as its clinical consequences, including both gastrointestinal symptoms and extraintestinal manifestations and/or laboratory abnormalities. The normal uptake of nutrients, vitamins, and minerals by the gastrointestinal tract (GI) requires several steps, each of which can be compromised in disease. This article will first describe the mechanisms that lead to poor assimilation of nutrients, and secondly discuss the symptoms and nutritional consequences of each specific disorder. The clinician must be aware that many malabsorptive disorders are manifested by subtle disorders, even without gastrointestinal symptoms (for example, anemia, osteoporosis, or infertility in celiac disease), so the index of suspicion must be high to recognize the underlying diseases in time.

Role of Capsule Endoscopy in Inflammatory Bowel Disease

In Crohn disease (CD), the use of capsule endoscopy (CE) for suspected versus established disease is very different. Most patients with CD are diagnosed with ileocolonoscopy. In patients with a negative ileocolonoscopy, CE is the next best test in suspected CD. In patients with established CD, the potential benefits of CE are rating severity of disease, establishing extent and distribution, and following mucosal healing in a treat to target strategy. In those with proximal small bowel disease, CE can help in diagnosis and prognostication. In ulcerative colitis, CE has a limited role, but that may change with evolving technology.

Seronegative autoimmune enteropathy with duodenal sparing and colonic clues in an adult female

Autoimmune enteropathy (AIE) is a rare immune disorder of the gut seldom found in adults and characterized by uncontrollable diarrhea resulting in malabsorption. While AIE is known to be pan-enteric, virtually all cases have presented with altered duodenal histology following known patterns with or without macroscopic change. We describe a unique case of seronegative AIE lacking typical duodenal manifestations in a 43-year-old female. To our knowledge, this is the first report of AIE lacking usual duodenal histologic changes, which resulted in missed diagnosis for years. Ultimately, crypt epithelial apoptosis, mononuclear inflammation of the lamina propria, and goblet cell loss of intestinal mucosa besides the duodenum clinched the diagnosis of AIE. Colonic histologic abnormalities consistent with AIE in the setting of diarrhea with malnutrition despite duodenal sparing should prompt suspicion for AIE given the pan-enteric nature of this disease.

Acute Flare of Adult-Onset Autoimmune Enteropathy Associated With Cyclophosphamide

This is a case of adult-onset autoimmune enteropathy (AIE) in a 46-year-old man with multiple autoimmune conditions who presented with worsening disease process after receiving cyclophosphamide. We describe the investigations and management of this patient over a 6-year timeline. The diagnosis and management of AIE is challenging given the heterogeneity in clinicopathologic findings and a small number of adult case reports. We describe the current diagnostic criteria, review the literature on treatment options and outcomes, and discuss the evidence for cyclophosphamide in the treatment of AIE. Adult-onset AIE should be considered in the differential diagnosis of refractory diarrhea and weight loss.

Immune-mediated enteropathies: From bench to bedside

Immune-mediated enteropathies are caused by excessive reactions of the intestinal immune system towards non-pathogenic molecules. Enteropathy leads to malabsorption-related symptoms and include (severe) chronic diarrhea, weight loss and vitamin deficiencies. Parenteral feeding and immunosuppressive therapy are needed in severe cases. Celiac disease has long been recognized as the most common immune-mediated enteropathy in adults, but the spectrum of immune-mediated enteropathies has been expanding. Histological and clinical features are sometimes shared among these enteropathies, and therefore it may be challenging to differentiate between them. Here, we provide an overview of immune-mediated enteropathies focused on clinical presentation, establishing diagnosis, immunopathogenesis, and treatment options.

Successful Treatment of Refractory Autoimmune Enteropathy With Ustekinumab

Autoimmune enteropathy (AIE) is a rare autoimmune disorder that has been described both in pediatric and adult patients and usually causes intractable watery diarrhea. The management of AIE is not standardized because the disease shows variable response to different immunosuppressive regimens including corticosteroids, azathioprine, cyclophosphamide, 6-mercaptopurine, tacrolimus, cyclosporine-A, infliximab, vedolizumab, and abatacept. We present a patient with adult-onset AIE and intractable high-volume diarrhea resulting in numerous hospitalizations and temporary parenteral nutrition, who is now successfully maintained on ustekinumab. Therefore, ustekinumab should be considered for further evaluation as a therapeutic option in cases of refractory AIE.

A Patient With AIRE Mutation Who Presented With Severe Diarrhea and Lung Abscess

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) (polyglandular endocrinopathy type 1) is a rare autosomal recessive disorder caused by mutations in the autoimmune regulator gene (AIRE). The major clinical features of APECED are hypoparathyroidism, adrenal insufficiency (Addison disease), and chronic mucocutaneous candidiasis. This disease is also associated with multiple other and uncommon autoimmune (autoimmune hepatitis, autoimmune enteropathy, atrophic gastritis with or without pernicious anemia, gonadal failure, diabetes mellitus, hypothyroidism, functional hyposplenism), ectodermal (alopecia and vitiligo), and inflammatory (intestinal lung disease, nephritis) features. Here, we report a case of a 13-year-old Turkish boy who presented wih enteropathy and lung abscess. Molecular genetic analysis demonstrated a homozygous frameshift mutation (p.Asp70fs, c.208_209insCAGG) in exon 2, in AIRE gene. APECED may present with severe, life-threatening infections due to functional hyposplenism. Multidisciplinary approach, careful follow-up, and molecular genetic studies are needed.

A Review of Autoimmune Enteropathy and Its Associated Syndromes

Autoimmune enteropathy is an extremely rare condition characterized by an abnormal intestinal immune response which typically manifests within the first 6 months of life as severe, intractable diarrhea that does not respond to dietary modification. Affected individuals frequently present with other signs of autoimmunity. The diagnosis is made based on a characteristic combination of clinical symptoms, laboratory studies, and histological features on small bowel biopsy. Autoimmune enteropathy is associated with a number of other conditions and syndromes, most notably immunodysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome and autoimmune polyglandular syndrome type 1 (APS-1). Diagnosis and treatment is challenging, and further research is needed to better understand the pathogenesis, disease progression, and long-term outcomes of these conditions.

Neuroendocrine Cells Are Commonly Absent in the Intestinal Crypts in Autoimmune Enteropathy

The absence of neuroendocrine (NE) cells in the intestinal mucosa in autoimmune enteropathy (AIE) has been occasionally reported. However, the status of NE cells has not been studied in detail in AIE. Small bowel and colonic biopsies were retrospectively retrieved from 18 AIE patients (26 baseline [18 small bowel and 8 colon]; and 15 follow-up [11 duodenum and 4 colon] biopsies in 11 patients). Thirty-three common variable immunodeficiency (CVID) patients (30 small bowel and 16 colon), 15 inflammatory bowel disease patients (5 duodenum and 10 colon), 13 immunoglobulinA deficiency patients (13 duodenum and 5 colon), and 10 normal controls (5 colon and 5 duodenum) were selected as control groups. Histologic features (villous atrophy, intraepithelial lymphocytosis, acute inflammation, crypt apoptosis, and absence or presence of goblet cells, Paneth cells and plasma cells) were recorded. Chromogranin immunostain was performed and chromogranin-positive NE cells were counted per 10 consecutive, well-oriented crypts. On the basis of the number of chromogranin-positive NE cells, cases were graded as being absent (≤3 NE cells), markedly decreased (≤15), and intact (>15). The NE cell status correlated with histologic features. The median age of 18 AIE patients was 38.5 years (range: 11 to 74 y) and 14 patients were male. Fourteen of 18 (78%) patients showed loss (absent or markedly decreased) of NE cells in the small bowel and/or colon in the baseline biopsies including 12 (of 18) small bowel and 6 (of 8) colon biopsies. Follow-up biopsy was available in 11 patients. Six of 7 (85%) patients who showed loss of NE cells in the baseline biopsies regained NE cells in the follow-up biopsies, and 1 patient continued to show loss of NE cells. Four patients who showed intact NE cells in the baseline remained unchanged in the follow-up. Among the control groups, 3 of 33 (9%) CVID patients showed loss of NE cells. NE cells were not lost in the biopsies of all 15 and 13 patients with inflammatory bowel disease and immunoglobulinA deficiency, respectively, or the 10 normal controls. In all 41 biopsies (26 baseline plus 15 follow-up) with AIE, NE cell loss was significantly associated with increased crypt apoptosis and loss of goblet cells (P=0.001, both) but not with other histologic findings. In conclusion, our study suggests that NE cells may also be the target cells in AIE and commonly lost in the intestinal crypts in AIE, and consequently loss of NE cells can be used as an adjunct histologic feature for diagnosis of AIE.

Updates in Pediatric Congenital Enteropathies: Differential Diagnosis, Testing, and Genetics

Congenital enteropathies comprise a heterogeneous group of disorders typically resulting in severe diarrhea and intestinal failure. Recent advances in and more widespread application of genetic testing have allowed more accurate diagnosis of these entities as well as identification of new disorders, provided a deeper understanding of intestinal pathophysiology through genotype-phenotype correlations, and permitted the exploration of more specific therapies to diseases that have heretofore been resistant to conventional treatments. The therapeutic armamentarium for these disorders now includes intestinal and hematopoietic stem cell transplantation, specific targeted therapy, such as the use of interleukin-1 receptor antagonists and, in some cases, gene therapy. These considerations are particularly applicable to the group of disorders identified as "very-early onset inflammatory bowel disease" (VEO-IBD), for which a veritable explosion of knowledge has occurred in the last decade. The pathologist plays a crucial role in assisting in the diagnosis of these entities and in ruling out other disorders that enter into the differential diagnosis.

[Autoimmune enteropathy in adults : A rare and difficult but relevant differential diagnosis of chronic diarrhea]

Autoimmune enteropathy (AIE) was originally believed to be a pediatric disease until there were increasing numbers of adult cases reported over the last 20 years. AIE is an autoimmune disease that manifests as severe chronic diarrhea.The histological hallmark is villous atrophy. Histology alone is not sufficiently sensitive and consistent. Four different histological patterns are known. There are many differential diagnoses to be considered relating to both histology and symptoms.We present the case of a young woman with fatal AIE and homozygous germline-mutation of the CLEC7A gene. The course of disease is documented in multiple intestinal biopsies, which show a morphological change over time.Histology and symptoms often resemble celiac disease. In order to recognize this rare disease early in its course there is a need for a special awareness among attending physicians and pathologists.

Isolated Intestine Transplantation for Autoimmune Enteropathy: A Case Report

Autoimmune enteropathy is a rare disease characterized by chronic watery diarrhea, weight loss, and immune-mediated injury of the enterocolic mucosa. The clinicopathologic findings of this disease are variable, and timely diagnosis is challenging. It is usually managed medically. If medical management fails, surgical intervention is considered. This is a case report of a patient with autoimmune enteropathy mimicking collagenous enterocolitis. A 55-year-old man developed intestinal failure that manifested as profuse watery diarrhea, electrolyte disturbances, and weight loss. Initially, he was diagnosed with collagenous enterocolitis based on pathologic findings. Medical interventions were started, but the patient failed to show improvement. At 13 months after the onset of the disease, he was listed for isolated intestine transplantation (IITX) for intestinal failure. A healthy donor graft became available. IITX with chimney colostomy was performed. Based on the pathologic findings of the excised native small intestine, the patient was diagnosed with severe autoimmune enteropathy. The postoperative course was uneventful. By the third postoperative week, a full diet was tolerated and parenteral nutrition (PN) was weaned to end. He was discharged on postoperative day 34. Since discharge, he has been off PN, remaining on an enteral diet. This case is the first reported IITX performed on a patient with severe autoimmune enteropathy that was both curative and lifesaving. The present case confirms that IITX promptly restores gastrointestinal absorption in medically refractory autoimmune enteropathy. This observation provides clinicians with an effective treatment option in this challenging group of patients.