Clinical and immunological features of adult-onset generalized autoimmune gut disorder

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.

Gut immune microenvironment and autoimmunity

A variety of immune cells or tissues are present in the gut to form the gut immune microenvironment by interacting with gut microbiota, and to maintain the gut immune homeostasis. Accumulating evidence indicated that gut microbiota dysbiosis might break the homeostasis of the gut immune microenvironment, which was associated with many health problems including autoimmune diseases. Moreover, disturbance of the gut immune microenvironment can also induce extra-intestinal autoimmune disorders through the migration of intestinal pro-inflammatory effector cells from the intestine to peripheral inflamed sites. This review discussed the composition of the gut immune microenvironment and its association with autoimmunity. These findings are expected to provide new insights into the pathogenesis of various autoimmune disorders, as well as novel strategies for the prevention and treatment against related diseases.

Pediatric autoimmune disorders with gastrointestinal expressions: from bench to bedside

The gastrointestinal (GI) tract may be involved in systemic autoimmune diseases or may be the target of organ-specific autoimmunity. Autoimmune enteropathy (AIE) is a rare disorder characterized by severe and protracted diarrhea, weight loss from malabsorption and immune-mediated damage to the intestinal mucosa, generally occurring in infants and young children, only rarely in adult. The salient histopathologic features of AIE are most prominent in the small intestine: villous blunting, crypt hyperplasia, mononuclear cell inflammatory expansion of the lamina propria with intraepithelial lymphocytosis, crypt apoptosis and absence of Paneth cells, goblet cells or both. Esophagus, stomach and colon are frequently also involved. Anti-enterocyte antibodies are identified in the majority of cases, and their presence, even if variable, can help confirming the diagnosis.

The purpose of this review is to provide an overview of the latest immunological advances in AIE, as well as to offer a practical approach for histological diagnosis for 'general' pathologist.

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.

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.

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.

Autoimmune Enteropathy: An Updated Review with Special Focus on Stem Cell Transplant Therapy

Autoimmune enteropathy (AIE) is a complex disease affecting both children and adults. Although associated with significant morbidity and mortality, the pathophysiology of the disease and its treatment have not been well characterized. This study aims to review the medical literature available on this rare but clinically significant ailment, to help establish a better understanding of its pathophysiology and enumerate the available diagnostic and treatment modalities. A literature search was conducted on PubMed using key terms related to autoimmune enteropathy and intractable diarrhea, with no restrictions on the date of publication or language. We found a total of 98 reports of AIE published in the form of case reports and case series. The evidence reviewed suggests that AIE is a multifaceted disorder that requires a high index of suspicion in the appropriate clinical setting to be able to make an early diagnosis. Current evidence supports the use of supportive care to correct nutritional and metabolic deficiencies, and immunosuppressives and immunomodulators as directed therapies. Hematopoietic stem cell transplant is an aggressive, but successful curative modality for patients with AIE as part of immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome. Cumulative clinical experience with management of AIE has allowed improved outcomes in transplanted and non-transplanted AIE patients even though morbidity and mortality with are still high in patients with this condition. More research is needed to further define the role of new therapies for AIE, and a central registry with participation of multiple institutions might help share and standardize care of patients with this rare but serious condition.

Autoimmune enteropathies

Autoimmune enteropathy (AIE) is a rare condition characterized by intractable diarrhea and immune-mediated injury of the intestinal mucosa. As the clinical and histopathologic manifestations of this disease are highly variable, its diagnosis is challenging for both clinicians and pathologists. In fact, the term autoimmune enteropathies is likely more appropriate since the clinicopathologic manifestations are observed in association with a heterogeneous group of disorders. The pathophysiology of AIE has not been fully elucidated. It appears to result from dysregulation of intestinal immunity and particularly in children, often presents in association with immunodeficiency. The overarching histopathologic changes seen in AIE include mucosal inflammation and epithelial injury, although this can manifest in the form of different patterns. Recognition of the clinical settings and of the various histologic patterns can aid the pathologist in establishing the correct diagnosis.

Gastrointestinal biopsy findings of autoimmune enteropathy: a review of 25 cases

Autoimmune enteropathy (AIE) is a rare disorder characterized by severe diarrhea and small intestinal mucosal atrophy resulting from immune-mediated injury. It remains a challenging diagnosis because of its clinicopathologic variability. To better understand its histopathologic features, we describe the gastrointestinal biopsy findings of 25 patients, including children and adults. The most common finding on small intestinal biopsy (13/25 cases, 52%) was villous blunting, expansion of the lamina propria by mixed but predominantly mononuclear inflammation, and neutrophilic cryptitis with or without crypt microabscesses. In 5 cases (20%), the duodenum exhibited changes indistinguishable from celiac disease, with villous blunting and intraepithelial lymphocytosis. Increased crypt apoptosis with minimal inflammation, resembling acute graft-versus-host disease, was observed in 4 cases (16%). The remaining 3 cases (12%) exhibited a mixture of 2 or more of the above patterns. Mucosal abnormalities outside the small intestine were present in all 24 cases with available biopsies (100%), with the stomach most commonly affected (19/22 cases, 86%), followed by the colon (14/22, 64%) and esophagus (5/18, 28%). Findings in non-small intestinal sites were variable and included mixed active and chronic inflammation, chronic inflammation alone, intraepithelial lymphocytosis, and increased apoptosis resembling acute graft-versus-host disease. In summary, AIE most commonly presents as an active enteritis with villous blunting and expansion of the lamina propria by mixed inflammation. Mucosal abnormalities are frequently seen elsewhere in the gut. AIE may thus be better regarded as a pan-gastrointestinal autoimmune disorder, and biopsies from sites other than the small intestine may greatly facilitate its diagnosis.

Autoimmune enteropathy: a review and update of clinical management

Autoimmune enteropathy (AIE) is a rare condition characterized by intractable diarrhea, histologic changes on small intestinal biopsy, and failed response to dietary manipulation that also may present with extraintestinal manifestations. In many patients, immunosuppressive therapies are necessary. Although AIE is more common in infants, adult involvement has also been documented. Much of what is known about AIE has been gathered from case reports and small case series; therefore, more research in this evolving field is needed. IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked syndrome) and APECED (autoimmune phenomena, polyendocrinopathy, candidiasis, and ectodermal dystrophy) are systemic forms of AIE.

Autoimmune enteropathy: a review and update of clinical management

Autoimmune enteropathy (AIE) is a rare condition characterized by intractable diarrhea, histologic changes on small intestinal biopsy, and failed response to dietary manipulation that also may present with extraintestinal manifestations. In many patients, immunosuppressive therapies are necessary. Although AIE is more common in infants, adult involvement has also been documented. Much of what is known about AIE has been gathered from case reports and small case series; therefore, more research in this evolving field is needed. IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked syndrome) and APECED (autoimmune phenomena, polyendocrinopathy, candidiasis, and ectodermal dystrophy) are systemic forms of AIE.

Autoimmune enteropathy with a CD8+ CD7- T-cell small bowel intraepithelial lymphocytosis: case report and literature review

Background

Adult onset autoimmune enteropathy (AIE) is a rare condition characterized by diarrhea refractory to dietary therapy diagnosed in patients with evidence of autoimmune conditions. Auto-antibodies to gut epithelial cells and other tissues are commonly demonstrated. Despite increasing awareness, the pathogenesis, histologic, immunologic and clinical features of AIE remain uncertain. There remains controversy regarding the diagnostic criteria, the frequency and types of auto-antibodies and associated autoimmune conditions, and the extent and types of histologic and immunologic abnormalities. CD4+ T-cells are thought to at least responsible for this condition; whether other cell types, including B- and other T-cell subsets are involved, are uncertain. We present a unique case of AIE associated with a CD8+CD7- lymphocytosis and review the literature to characterize the histologic and immunologic abnormalities, and the autoantibodies and autoimmune conditions associated with AIE.

Case Presentation

We present a case of immune mediated enteropathy distinguished by the CD8+CD7- intra-epithelial and lamina propria lymphocytosis. Twenty-nine cases of AIE have been reported. The majority of patients had auto-antibodies (typically anti-enterocyte), preferential small bowel involvement, and predominately CD3+ CD4+ infiltrates. Common therapies included steroids or immuno-suppressive agents and clinical response with associated with histologic improvement.

Conclusions

AIE is most often characterized (1) IgG subclass anti-epithelial cell antibodies, (2) preferential small bowel involvement, and (3) CD3+ alphabeta TCR+ infiltrates; there is insufficient evidence to conclude CD4+ T-cells are solely responsible in all cases of AIE.

Congenital diarrheal disorders: improved understanding of gene defects is leading to advances in intestinal physiology and clinical management

Congenital diarrheal disorders (CDD, Online Mendelian Inheritance in Man [OMIM] 251850) represent one of the most challenging clinical conditions for pediatric gastroenterologists because of the severity of the clinical picture and the broad range of disorders in its differential diagnosis. The number of conditions included within CDD has gradually increased. Recent advances made in the pathophysiology of these conditions have led to a better understanding of the more common diarrheal diseases. Based on the body of data accumulated in recent years, we suggest that CDD be classified in 4 categories depending on the alteration in absorption and transport of nutrients and electrolytes, enterocyte differentiation and polarization, enteroendocrine cell differentiation, and modulation of the intestinal immune response. Our knowledge of the genes responsible for CDD is also rapidly increasing, thanks to linkage studies based on genome-wide analysis of polymorphisms. In this context, the identification of disease genes is a step forward in the diagnostic approach to a patient in whom CDD is strongly suspected. However, it is conceivable that faster, less expensive molecular procedures will, in the near future, become available. This approach could spare the patient invasive procedures and limit complications associated with a delay in diagnosis. Furthermore, carrier and prenatal molecular diagnosis may help pediatricians better manage the condition in the early stages of life.

Autoimmune enteropathy in children and adults

Autoimmune enteropathy is a rare disorder characterized by severe and protracted diarrhea, weight loss from malabsorption and immune-mediated damage to the intestinal mucosa, generally occurring in infants and young children, although some cases of adult onset have been reported in the literature. Pathogenetic mechanisms involve immunological disorders, in which the presence of antienterocyte autoantibodies, although detected since first description, seems now to be secondary. As occurs frequently in autoimmunity, subjects with autoimmune enteropathy may be affected by other autoimmune disorders, sometimes leading to particular forms, i.e. the IPEX syndrome and the APECED syndrome. The prognosis of autoimmune enteropathy patients depends on the severity of digestive symptoms (including fecal output), on the severity and extension of histological lesions along the gastrointestinal apparatus, and on the presence of extra-intestinal involvement. Management of autoimmune enteropathy patients is based on nutritional support and adequate hydration to ensure optimal growth and development, together with immunosuppressive therapy. Recently, biological agents have been introduced, with apparent beneficial effects.

Adult autoimmune enteropathy

Recent reports have suggested that autoimmune enteropathy involving the small bowel may occur in adults as well as in children. Apparently, the endoscopic and histological changes are similar to celiac disease before treatment, but these are not altered by any form of dietary restriction, including a gluten-free diet. As in celiac disease, histologic changes in gastric and colonic biopsies have also been recorded. Anti-enterocyte antibodies detected with immunofluorescent methods have been reported by a few laboratories, but these antibodies appear not to be specific and may simply represent epiphenomena. A widely available, reproducible and quantitative anti-enterocyte antibody assay is needed that could be applied in small bowel disorders that have the histological appearance of celiac disease, but fail to respond to a gluten-free diet.

Adult autoimmune enteropathy: Mayo Clinic Rochester experience

BACKGROUND & AIMS

Autoimmune enteropathy is a rare cause of intractable diarrhea associated with circulating gut autoantibodies and a predisposition to autoimmunity. It is rarely observed in adults, with only 11 cases reported to date.

METHODS

Fifteen adults with autoimmune enteropathy were identified at the Mayo Clinic, Rochester, from May 2001-June 2006. The demographic, clinical, and treatment data were abstracted from their records.

RESULTS

The study population was 87% white, 47% female, with median age of 55 years (interquartile range, 42-67 years). All patients had protracted diarrhea, weight loss, and malnutrition. Celiac disease was excluded by lack of response to gluten-free diet or absence of the celiac disease susceptibility HLA genotypes. Fourteen patients were tested for gut epithelial cell antibodies, and 93% were positive for anti-enterocyte and/or anti-goblet cell antibodies. Predisposition to autoimmune diseases was noted in 80%, as indicated by a variety of circulating autoantibodies. Small intestinal histopathologic findings included subtotal villous atrophy and lymphoplasmacytic infiltration in the lamina propria with relatively few surface intraepithelial lymphocytes. T-cell receptor gene rearrangement studies were negative in all cases. Immunosuppressive therapy was required in 93% of cases. Clinical improvement was noted in 60% after 1-8 weeks of steroid therapy.

CONCLUSIONS

Autoimmune enteropathy is a heterogeneous disease and should be considered in the differential diagnosis of malabsorption and small bowel villous atrophy. The presence of gut epithelial cell antibodies can help confirm the diagnosis. No single agent is unequivocally effective in inducing remission, and immunosuppressive therapy is required in most cases.

Severe FOXP3+ and naïve T lymphopenia in a non-IPEX form of autoimmune enteropathy combined with an immunodeficiency

BACKGROUND & AIMS

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is the best-characterized form of a rare entity called autoimmune enteropathy (AIE). IPEX syndrome is due to mutations in the FOXP3 gene, a transcription factor essential for the development and function of the natural regulatory CD25(+)CD4(+) T cells. We studied a female patient with a polyautoimmune AIE syndrome resembling a mild form of IPEX syndrome but associated with recurrent bacterial infections and mild hypogammaglobulinemia. We hypothesized that this syndrome combined a deficit of FOXP3(+) cells and other lymphocyte populations.

METHODS

We analyzed the major lymphocyte subsets and the FOXP3(+) regulatory system in blood samples obtained during the 2-year period that followed the last autoimmune manifestation.

RESULTS

The patient had severe naïve T lymphopenia and a major deficit of FOXP3(+)CD4(+) T cells, both in circulation and in the highly inflamed intestinal mucosa, but mutations in the FOXP3 locus were excluded. The blood FOXP3(+) pool was devoid of CD25(high) cells, but the few regulatory CD25(+) cells were functional. Intrinsic defects in the expression of CD25, FOXP3, and interleukin 2 were excluded. Upon activation, a small subset of cells, presumably committed to regulatory function, sustained expression of CD25 and FOXP3.

CONCLUSIONS

Peripheral T lymphopenia of both naïve and natural regulatory T cells might be the consequence of defective thymic production or the short life span of exported T cells. This case sheds new light in the etiology of autoimmune manifestations in T-cell immunodeficiencies and in the heterogeneity of AIE.

Age-related variation of intraepithelial lymphocytes subsets in normal human duodenal mucosa

The enumeration of intestinal intraepithelial lymphocytes (IELs), and the phenotyping of CD3+CD 103+ (TcRalphabeta, TcRgammadelta) and CD3-CD103+ IEL subsets constitute useful diagnostic tools for the correct interpretation of the mucosal histology of duodenal/jejunal biopsies in many pathological conditions of the small intestine, particularly celiac disease (CD). This work evaluates the ranges of duodenal IEL counts by flow cytometry in healthy mucosa from pediatric and adult controls, establishing normal reference values for CD3+ TcRgammadelta and CD3- subsets and their variation with age. Seventy-four pediatric controls and 36 adult controls were identified on the basis of their normal histology from more than 1,000 duodenal diagnostic biopsies performed in Caucasian subjects. Total IEL counts and IEL subsets ("IEL lymphogram") were analyzed by four-color flow cytometry (FCM). IEL represent 7.7% +/- 0.4 (mean +/- SE) and 8.5% +/- 0.5 of the cells isolated from the epithelium in the pediatric and adult series, respectively. The upper normal range, considered as the 97 percentile, is 14% in pediatrics and 15% in adults. No significant difference was observed between TcRgammadeltaIEL percentages in children (6.9% +/- 0.5 of the total IELs) and adults (6.6% +/- 0.8). However, the density of CD3- IELs is significantly higher (p < 0.001) in the mucosa from controls under 3 years (50.2% +/- 2.6) than in adults (25.5% +/- 2.1). IEL lymphogram by flow cytometry is an easy, quick and reliable analysis performed in one of the biopsy specimens obtained during a diagnostic endoscopy, and confers specificity to the histopathological findings. IEL counts below 14% in children and 15% in adults should be considered within a normal range in the evaluation of duodenal mucosa by FCM. No differences with age were observed with respect to TcRgammadeltaIEL, while the CD3- IEL fraction was significantly higher on children under 3 years, with a trend to increase again in the elderly.

The pathology of malabsorption: current concepts

Intestinal malabsorption results from a wide variety of causes, which can most easily be organized into three groups. Maldigestion arises from problems with mixing or with digestive mediators, and includes post-gastrectomy patients and those with deficiencies of pancreatic or intestinal enzymes, or of bile salts. Mucosal and mural causes of malabsorption are abundant, and include gluten-sensitive enteropathy, tropical sprue, autoimmune enteropathy, and HIV/AIDS-related enteropathy, as well as mural conditions such as systemic sclerosis. Finally, microbial causes of malabsorption include bacterial overgrowth, Whipple's disease, and numerous infections or infestations that are most frequently seen in immunocompromised patients. An overview of the most common and interesting entities in each of these categories follows, along with a discussion of current concepts. Mucosal conditions and microbial causes of malabsorption are given special attention.

Enteropathy with loss of enteroendocrine and Paneth cells in a patient with immune dysregulation: a case of adult autoimmune enteropathy

Autoimmune enteropathy (AIE) is a relatively rare condition found most frequently in children. It presents with persistent watery diarrhea and malabsorption and may require total parenteral nutrition for nutritional support. Rare cases have been reported in adults. On histology, the small intestinal villi are flattened but lack the intraepithelial lymphocytosis of celiac disease. In children and rarely in adults, some cases are linked to the IPEX syndrome (Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked inheritance). We report a 21-year-old man who presented with chronic persistent diarrhea for 4 years. The duodenal biopsies showed villous blunting, chronic inflammation, and decreased to absent goblet cells, Paneth cells, and endocrine cells by histology and electron microscopy. These changes are consistent with an AIE with involvement of non-enterocyte populations. Pathologists must be aware of the possibility of AIE in adults and consider it in the differential diagnosis of duodenitis, intraepithelial lymphocytosis, and small bowel villous flattening.

Gluten sensitive enteropathy and other causes of small intestinal lymphocytosis

Recent studies on gluten sensitive enteropathy (GSE) have heightened the pathologist's awareness of intraepithelial lymphocytes in duodenal biopsies. Mild histologic forms of GSE are now recognized with increased IELs as the only histologic change. In this review, both the classic morphology and "minimal deviation" GSE are discussed in detail, with special emphasis on the differential diagnosis and how to avoid overdiagnosing this condition. The Marsh-Oberhuber classification is described and contrasted with a more practical diagnostic terminology that is recommended for use in pathology reports. Other important conditions associated with duodenal lymphocytosis, such as refractory sprue, autoimmune enteropathy, and Helicobacter pylori-associated duodenitis, are also presented.