Unresponsive enteropathy associated with circulating enterocyte autoantibodies in a boy with common variable hypogammaglobulinemia and type I diabetes

Clinical manifestations and gastrointestinal pathology in 40 patients with autoimmune enteropathy

Autoimmune enteropathy (AIE) is a rare condition that may affect pediatric and adult patients, frequently associated with primary immunodeficiencies. We performed a retrospective study on clinical and histological findings from 40 AIE patients. Histological presentation showed a prevalent celiac disease pattern (50%), followed by the mixed pattern (35%), independently of age, chronic active duodenitis (10%), and GVHD-like pattern (5%). Patients with primary immunodeficiencies (24/40) presented mainly with the celiac disease pattern (72.2% versus 22.2%; p < .0001), while patients without primary immunodeficiencies presented with a mixed histological pattern (61.1% versus 13.6%; p < .0001). Our study shows that the prevalent histological presentation is the celiac disease-like pattern, independently of age, and, for the first time, that the histological presentation of AIE differs significantly between patients with and without primary immunodeficiencies. These findings may be helpful for more precise and timely diagnosis and management of this rare disorder.

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.

Increased prevalence of gastrointestinal viruses and diminished secretory immunoglobulin a levels in antibody deficiencies

PURPOSE

Gastrointestinal disease occurs frequently in antibody deficiencies. This study aims to explore the relation between gastrointestinal infections and mucosal homeostasis in patients with antibody deficiencies.

METHODS

We performed an observational study including 54 pediatric antibody deficient patients (48 % CVID, 41 % CVID-like, 11 % XLA) and 66 healthy controls. Clinical symptom scores and stool samples were collected prospectively. Stool samples were evaluated for bacteria, parasites, viruses, secretory IgA- and for calprotectin levels. Results were compared between patients and controls.

RESULTS

24 % of antibody deficient patients versus 9 % of healthy controls tested positive for gastrointestinal viruses (p = 0.028). Fecal calprotectin levels were significantly higher in virus positive patients compared to virus negative patients (p = 0.002). However, in controls, fecal calprotectin levels were similar between virus positive and virus negative controls. Moreover, gastrointestinal virus positive patients had low serum IgA levels in 13/14 cases (94 %) versus 40/62 (62 %) patients in the virus negative patient group (p = 0.04). The virus positive patient group also displayed significantly lower secretory IgA levels in stool (median 13 ug/ml) than patients without gastrointestinal viruses detected or healthy controls (median 155 ug/ml) (p = 0.046).

CONCLUSION

We here report an increased prevalence of gastrointestinal viruses and gastrointestinal complaints in antibody deficient patients. Patients that tested positive for gastrointestinal viruses showed diminished serum- and secretory IgA levels, and only in patients, virus positivity was associated with signs of mucosal inflammation. These findings suggest that particularly patients with low IgA are at risk for longstanding replication of gastrointestinal viruses, which may eventually result in CVID-related enteropathy.

Pediatric autoimmune enteropathy: an entity frequently associated with immunodeficiency disorders

The term pediatric autoimmune enteropathy was originally applied to a form of intractable diarrhea seen in children under the age of 6 months and characterized by male predominance, concurrent autoimmune-associated disorders, circulating gut autoantibodies, a lack of severe immunodeficiency and small bowel atrophy with prominent crypt apoptosis. However, recent studies have cast doubt over the specific clinicopathologic findings associated with this entity. We, therefore, collected 178 gastrointestinal biopsies from 14 patients and examined their clinical, serologic and pathologic findings. Patients at presentation ranged in age from birth to 15.9 years (median, 5.5 months; mean, 4.1 years) and included six males and eight females. All children suffered from chronic watery diarrhea and malnutrition. Concomitant-associated disorders were noted in 11 (79%) cases and included 10 (71%) with an immunodeficiency disorder and/or another autoimmune-related disease. Eleven patients (79%) were positive for anti-enterocyte antibodies. The salient findings of autoimmune enteropathy were most prominent in the small intestines and the majority (79%) of patients demonstrated villous blunting, crypt hyperplasia, mononuclear cell inflammatory expansion of the lamina propria and crypt apoptosis. The remaining (21%) patients showed marked intraepithelial lymphocytosis reminiscent of celiac disease. Further, acute cryptitis and crypt abscesses were seen in seven (50%) patients obscuring the presence of apoptosis. The absence of Paneth cells, goblet cells or both was noted in seven (50%) patients. Follow-up information was available for all patients with 13 (93%) receiving immunosuppressant therapy and demonstrating partial-to-complete response. In total, three patients died from continued diarrhea and sepsis with one decedent before treatment could be initiated. In summary, autoimmune enteropathy in children is a heterogenous disease with protean clinical and pathologic findings. Although anti-enterocyte antibodies were identified in the majority of the cases, their presence was variable and insensitive. In addition, pediatric autoimmune enteropathy was frequently encountered in the setting of immunodeficiency disorders.

Histopathology of celiac disease

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

The enteropathy associated with common variable immunodeficiency: the delineated frontiers with celiac disease

OBJECTIVES

The enteropathy associated with common variable immunodeficiency (CVID) is poorly characterized, and its possible relationships with well-defined causes of enteropathy, such as celiac sprue (CS), remain debated. We aimed to assess the clinical and histopathological features of the enteropathy associated with CVID.

METHODS

The medical files of 50 CVID patients with gastrointestinal symptoms were analyzed retrospectively. Histological, phenotypic, and molecular analysis of intestinal endoscopic specimens was centrally performed.

RESULTS

Chronic diarrhea was the most frequent gastrointestinal symptom (92%), and biological evidence of malabsorption was observed in 54% of patients. Chronic gastritis associated or not with pernicious anemia and microscopic colitis were the most frequently observed histopathological features in gastric and colonic mucosa, respectively. Small-bowel biopsies available in 41 patients showed moderate increase in intestinal intraepithelial lymphocytes in 31 patients (75.6%) and villous atrophy in 21 patients (51%). Distinctive features from CS were a profound depletion in plasma cells and follicular lymphoid hyperplasia. Presence of peripheral blood CD8+ hyperlymphocytosis was predictive of intestinal intraepithelial hyperlymphocytosis. Intravenous (i.v.) immunoglobulin (Ig) therapy had no effect on enteropathy-related symptoms. Gluten-free diet improved only two out of 12 patients with villous atrophy, whereas all patients (7/7) responded to steroid therapy.

CONCLUSIONS

Several distinctive features differentiate CVID enteropathy from other causes of enteropathy including CS. Replacement i.v. Ig therapy is insufficient to improve gastrointestinal symptoms. Steroids are effective in reducing inflammation and restoring mucosal architecture.

Enteropathies of Infancy and Childhood

Intestinal biopsies constitute an ever-increasing portion of the pathologist's workload, accounting for nearly two-thirds of specimens accessioned yearly by the pathology department at The Children's Hospital of Philadelphia. The widespread use of endoscopy and gastrointestinal biopsies in current clinical practice presents the pathologist with a diversity of intestinal mucosal appearances corresponding to disease states of variable clinical severity, requiring close collaboration between clinician and pathologist for optimal interpretation. Many of the entities resulting in severe diarrhea of infancy have been recognized only in the last several decades, and although rare, the study of these disorders, especially when combined with the powerful methods of present-day genetics and molecular biology, has afforded important insights into enterocyte development and function, and intestinal immunity and tolerance. Other conditions once considered infrequent, such as celiac disease, have now been recognized to be much more common and can present with a wide range of pathologic features.

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.

Update in understanding common variable immunodeficiency disorders (CVIDs) and the management of patients with these conditions

The common variable immunodeficiency disorders are a mixed group of heterogeneous conditions linked by lack of immunoglobulin production and primary antibody failure. This variability results in difficulty in making coherent sense of either immunopathogenesis or the role of various genetic abnormalities reported in the literature. The recent attempt to collate the varied complications in these conditions and to define particular clinical phenotypes has improved our understanding of these diseases. Once refined and confirmed by other studies, these definitions will facilitate improved accuracy of prognosis and better management of clinical complication. They may also provide a method of analysing outcomes as related to new immunopathological and genetic findings.

Clinical and molecular aspects of autoimmune enteropathy and immune dysregulation, polyendocrinopathy autoimmune enteropathy X-linked syndrome

PURPOSE OF REVIEW

Autoimmune enteropathy (AIE) is a distinct cause of severe and persistent inflammatory diarrhea in children. Recent research data allowed us to gain a first insight in the pathogenesis of AIE. On the basis of this data, we will discuss new aspects of AIE emphasizing new diagnostic and therapeutic possibilities.

RECENT FINDINGS

With the discovery of disease-causing mutations in the FOXP3 gene in patients with AIE, a dramatic advance in the understanding of AIE was made. Subsequent studies indicated that FOXP3 is a key transcription factor indispensable for regulatory functions of T cells pointing to a critical role of regulatory T-cell homeostasis in the development of AIE. Abnormal FOXP3 expression results in defective regulatory functions of T cells, which in turn cause a systemic T-cell-mediated autoaggressive disorder, now called immune dysregulation, polyendocrinopathy autoimmune enteropathy X-linked syndrome. Upon systematic review, we describe different phenotypes of immune dysregulation polyendocrinopathy autoimmune enteropathy X-linked syndrome, as well as immune dysregulation polyendocrinopathy autoimmune enteropathy X-linked-like forms of AIE, which are FOXP3 independent. No genotype-phenotype correlation could be established so far.

SUMMARY

On the basis of the profound immune dysregulation in AIE, new, most often T-cell-oriented treatment strategies were developed. The recent molecular advances in the understanding of AIE give a clear rational for the use of immunosuppression (combining steroids and tacrolimus or rapamycine) to stabilize AIE patients or to perform bone marrow transplantation in those who do not respond to immunomodulation.

Excess IL-12 but not IL-23 accompanies the inflammatory bowel disease associated with common variable immunodeficiency

BACKGROUND & AIMS

Common variable immunodeficiency (CVID) patients can develop an idiopathic inflammatory bowel disease resulting in chronic diarrhea and life-threatening malabsorption. This study was designed to assess the status of the gastrointestinal tract and to define the mucosal immune abnormalities in patients with and without symptomatic gut inflammatory disease.

METHODS

CVID patients underwent tests of gut absorption, peripheral blood mononuclear cell phenotyping, and upper and lower endoscopy for histology and lamina propria mononuclear cell (LPMC) cytokine production.

RESULTS

CVID patients with gastrointestinal symptoms differed from asymptomatic CVID patients by having significantly longer duration of disease and lower body mass index, D-xylose absorption, serum albumin, CD4/CD45RA cells, CD3/CD25 cells, and natural killer cells. Symptomatic CVID patients showed diffuse histologic inflammatory changes in the duodenal and colonic mucosa including villus blunting, increased lamina propria and intraepithelial lymphocytes, and epithelial apoptosis, less frequently seen in asymptomatic patients. LPMCs from symptomatic CVID patients produced significantly higher T-helper (Th) 1 cytokines, interleukin-12, and interferon-gamma. Compared with the Th1 cytokines produced by LPMCs from Crohn's disease, CVID patients did not produce excess amounts of interleukin-23, interleukin-17, or tumor necrosis factor-alpha.

CONCLUSIONS

The idiopathic inflammatory bowel disease associated with gastrointestinal symptoms in CVID is a unique combination of diverse histologic findings accompanied by excessive Th1 cytokine production, distinct from that in Crohn's disease. These data show that human gut mucosal inflammatory disease can occur with excess interleukin-12 and interferon-gamma production alone and provide a rationale for developing targeted therapies for this complication of CVID.

Autoimmune enteropathy: molecular concepts

PURPOSE OF REVIEW

Enteropathies causing temporary or permanent intestinal failure are a big diagnostic and therapeutic challenge for pediatric gastroenterologists. A now well-recognized and distinct entity is in the form of "autoimmune enteropathy (AIE)". Recent advances in the molecular workup of AIE gave first insight into the pathophysiology of AIE. In this review, we discuss new molecular concepts of AIE resulting in new diagnostic and therapeutic possibilities.

RECENT FINDINGS

The identification of disease-causing mutations in the FOXP3 gene as a basic defect resulting in AIE points to a defect in regulatory T-cell homeostasis. FOXP3, primarily expressed by CD4+CD25+regulatory T cells, is a potent transcriptional suppressor and key modulator of T-cell functions. Nonfunctional FOXP3 leads to a tremendous hyperactivation of T cells, resulting in autoimmune aggression, such as seen in patients with immune dysregulation, polyendocrinopathy autoimmune enteropathy X-linked (IPEX) syndrome, a subgroup of AIE. There is recent evidence suggesting that a defect of regulatory factors other than FOXP3 might cause AIE. Anti-enterocyte autoantibodies, another main characteristic of AIE, seem to be of a secondary nature and can no more be considered as directly disease causing.

SUMMARY

Based on the profound immune dysregulation, new treatment strategies emerged for AIE. The use of T-cell immunosuppressive drugs, such as tacrolimus combined to steroids, seems to be beneficial in some patients; however, long-term remission is not always possible. Bone marrow transplantation might be the treatment of choice in those patients who do not respond to immunosuppression; however, the first encouraging results remain to be confirmed since to date long-term outcome remains mixed.

Common variable immunodeficiency and the gastrointestinal tract

Common variable immunodeficiency (CVID) is the second most prevalent primary immunodeficiency disorder but clinically the most important. It causes a wide spectrum of symptoms and signs affecting many systems of the body. CVID is a combination of humoral and cell-mediated deficiency, which explains not only why so many systems are affected but also why standard therapy in the form of intravenous immunoglobulin is not always effective. The gastrointestinal tract is the largest immune organ in the body, and it is therefore expected that this immunodeficiency will affect it in some way. The gastrointestinal manifestations of CVID are variable and tend to mimic known diseases, such as celiac sprue, pernicious anemia, and inflammatory bowel disease, but show significant differences on the microscopic level. Many studies continue to confirm a high prevalence of inflammatory, malignant, and infectious gastrointestinal disorders in patients with CVID. The T-cell-mediated defects of this immunodeficiency disorder are thought to be the cause of the majority of the gastrointestinal disorders in CVID and not the antibody deficiency. Therefore, intravenous immunoglobulin alone may be ineffective. Combination therapy with immunomodulators, such as azathioprine and 6-mercaptopurine, may be needed to treat these gastrointestinal manifestations of CVID.

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

OBJECTIVES

Autoimmune enteropathy is a rare disorder of unknown pathogenesis, characterized by protracted diarrhea, villous atrophy, and enterocyte autoantibodies. Its association with extended inflammation of the whole gastrointestinal tract is termed as generalized autoimmune gut disorder (GAGD), generally a pediatric disease of difficult management due to its association with immunodeficiency. The aim of our work is to describe the mucosal immunological basis of an adult-onset case of GAGD.

METHODS

We studied an adult female with a severe inflammatory involvement of the gastrointestinal tract (stomach, small and large bowel, and liver) and antienterocyte autoantibodies. She had antibody deficiency and a predisposition to systemic autoimmunity. We analyzed, by immunohistochemistry and flow cytometry, the phenotypic and functional characteristics of her intestinal intraepithelial and lamina propria (LP) lymphocytes.

RESULTS

We observed the prominent and constant presence of an unusual CD4+alphaE/beta7- Tc subset in the jejunal epithelium. Signs of the lymphocyte activation as well as the prominent lymphoid TNF-alpha production observed in the rectal mucosa support the involvement of a cell-mediated pro-inflammatory response in the pathogenesis of GAGD.

CONCLUSIONS

We report the second case of an adult fulfilling all diagnostic criteria for GAGD. We propose that the activated LP CD4+ T lymphocytes, as well as those atypically located in the epithelium, may play a pathogenic role. The alphaE/beta7- IEL could constitute a diagnostic marker of intestinal autoimmunity in the cases when autoantibodies are not evidenced, and mucosal TNF-alpha might represent a novel therapeutic target in this severe disease.

Coeliac- and enteropathy-associated autoantibodies in Spanish insulin-dependent diabetes mellitus patients and their relation to HLA antigens

The frequency of reticulin (ARA), endomysium (EmA), and gut epithelial cell (GECA) autoantibodies, and gliadin antibodies (AGA), was investigated in 86 Spanish diabetic patients by indirect immunofluorescence (IFI) and ELISA, along with their HLA phenotype. Four patients (5%) showed ARA-IgG (R1 pattern), eight (9%) showed AGA-IgG, and eight (9%) showed AGA-IgA. No EmA or GECA-positive patients were found. In diabetic patients, HLA-DR7 is increased in ARA-IgG+ vs. ARA-IgG- (though not significantly), and HLA-DR6 and HLA-DQ1 are significantly increased in the AGA-IgG+ group vs. the AGA-IgG- group. Comparison with a non-diabetic coeliac group showed that HLA-DR4 and HLA-DQ3 are significantly increased in the AGA-IgA+ group, whereas HLA-DQ2 shows a significant decrease in the AGA-IgG+ and AGA-IgA+ patients. Finally, when compared to the healthy group, HLA-DR7 frequency is decreased in the ARA-IgG- group, while HLA-DQ3 is significantly increased and HLA-DR6 and HLA-DQ1 significantly decreased in the AGA-IgG- group.Altogether, these data suggest that the genetic background leading to the appearance of coeliac-specific autoantibodies in Spanish diabetic patients differ depending on the autoantibody produced and is also different to the genetic background leading to diabetes in Spain.

Severe and protracted diarrhea: results of the 3-year SIGEP multicenter survey. Working Group of the Italian Society of Pediatric Gastroenterology and Hepatology (SIGEP)

BACKGROUND

The spectrum of severe and protracted diarrhea (SPD), previously defined as intractable diarrhea, has changed during the past several decades. Despite recent advances in determining the cause of SPD and in treatment, this syndrome still represents a challenge and is becoming a major problem affecting health care resources. This study was conducted to characterize the epidemiology, spectrum of causes, and the outcome of SPD in Italy in recent years.

METHODS

All the SPD cases seen at the major centers of pediatric gastroenterology in Italy during a 3-year period (1993-1996) were recruited in this multicenter, prospective survey.

RESULTS

Thirty-two children (26 boys and 6 girls; median age at the onset of SPD, 40 days) were enrolled in this study by 9 of 26 participating centers. Twelve were newly diagnosed cases, with an estimated SPD incidence rate in Italy of 0.64 to 0.92 x 10(-5) infants per year. The most common causes were autoimmune enteropathy (n = 8) and ultrastructural abnormalities of the enterocyte (n = 7), whereas food intolerance and postenteritis syndrome were less frequent (3 and 2 cases, respectively). Two children with autoimmune enteropathy fulfilled the criteria for the X-linked variant of this condition. At the end of the study period, 9 of 31 patients had recovered, 15 still had diarrhea, and 7 had died.

CONCLUSIONS

Severe and protracted diarrhea is a rare but challenging problem in Italy. Because parenteral nutrition or intestinal transplantation are the only options in a subset of cases (e.g., ultrastructural abnormalities of the enterocyte), infants with SPD should be referred to specialized centers where advanced diagnostic and therapeutic facilities are available.

Autoimmune enteropathy

Autoimmune enteropathy (AIE) is an entity reported primarily in infancy, resulting in intractable diarrhea and associated with small bowel villous atrophy and the presence of circulating anti-enterocyte (AEA) antibodies. It is a multisystem disorder with a response, in many cases, to immunosuppressive therapy.

Syndrome of intractable diarrhoea with persistent villous atrophy in early childhood: a clinicopathological survey of 47 cases

BACKGROUND

The syndrome of intractable diarrhoea of infancy is heterogeneous and includes several diseases with diverse aetiologies. This study determines whether diagnostic categories can be defined on the basis of clinicopathological analysis.

METHODS

European Society of Paediatric Gastroenterology, Hepatology and Nutrition members were surveyed to identify cases of intractable diarrhoea with persisting small intestinal enteropathy. A retrospective clinicopathological analysis was performed on cases showing life-threatening diarrhoea within the first 24 mo of life and requiring total parenteral nutrition, which were characterized by persistent villous atrophy, and resistance to therapy.

RESULTS

Forty-seven infants were identified with intractable diarrhoea. Villous atrophy was of varying degrees with (group I, n = 24) or without (group II, n = 18) lamina propria mononuclear cell infiltration. Group I presented later, had gut autoantibodies, and a higher prevalence of protein-losing enteropathy; a subset (group Ia, n = 12) also had extraintestinal symptoms of autoimmunity associated with a later onset of larger volume diarrhoea. Group II presented early; 8 cases (group IIa) had phenotypic abnormalities and a low birth weight; the remaining 10 (group IIb) showed mild-to-moderate villous atrophy, epithelial tufting, and abnormal crypts. Group III included five patients in whom no specific features were recognised. Twenty-one (45%) died at a median age of 24 months, 20 (43%) remained dependent on parenteral (n = 16) or enteral tube (n = 4) feeding, 4 (9%) received elimination diets plus other therapies, and 2 (4%) were lost to follow-up.

CONCLUSIONS

Clinicopathological analysis allowed distinct disease groups to be identified, allowing a provisional classification to be made. This straightforward approach forms a basis for future research in this exceptionally difficult paediatric condition.

Autoimmune enteropathy and villous atrophy in adults

BACKGROUND

Autoimmune enteropathy is a condition described in children and characterised by villous atrophy, which is unresponsive to any dietary restrictions, and by the presence of enterocyte autoantibodies. We report two adult patients who fulfilled all the criteria for the diagnosis of this disorder.

METHODS

Over the past 5 years we have seen four adult patients (all women, median age 51.5 [range 38-64] years) with subtotal villous atrophy, which was unresponsive to a gluten-free diet. The patients were HLA-DQ2 positive. IgA antigliadin and antiendomysial antibodies were not found in any of the patients. We did an indirect immunofluorescence search for enterocyte autoantibodies on monkey jejunum and for other autoantibodies for all four patients.

FINDINGS

Of the four patients, two were positive for enterocyte autoantibodies and one of these two patients was positive for antiactin, antiparietal cell, and antithyroid microsomal autoantibodies.

INTERPRETATION

To the best of our knowledge the two patients affected by severe enteropathy, who had never responded to any exclusion diet, and who were positive for enterocyte autoantibodies are the first cases of autoimmune enteropathy described in adults. We propose that adult patients whose disorders are unresponsive to a gluten-free diet should be tested for enterocyte autoantibodies.

Gastrointestinal pathology in patients with common variable immunodeficiency and X-linked agammaglobulinemia

Review of the medical records of 43 patients with common variable immunodeficiency (CVID) and 23 patients with X-linked agammaglobulinemia (XLAG) revealed a high incidence of chronic gastrointestinal complaints, most commonly diarrhea. Thirty-eight biopsies, four small-bowel resection specimens, and one autopsy from 10 patients with CVID and one patient with XLAG showed a wide range of abnormalities. A pattern resembling acute graft-versus-host disease, with apoptotic bodies and lymphocytes in crypts, was seen in the stomach (four patients), small bowel (three patients), and colon (three patients). Small-bowel specimens from three CVID patients with malabsorption showed mild to severe villous atrophy. Three CVID patients had Giardia in biopsies. Two cases of small bowel lymphoma associated with nodular lymphoid hyperplasia were identified in CVID patients. One patient's small bowel contained foamy histiocytes in the lamina propria, resembling Whipple's disease or chronic granulomatous disease, with numerous apoptotic bodies in crypts. Ultrastructurally, the histiocytes contained cellular debris. The patient with XLAG had recurrent fissuring necrosis of small bowel resembling Crohn's disease; a patient with CVID had colitis with features similar to ulcerative colitis. Poorly formed granulomas were seen in the stomach (one CVID patient) and the colon (two CVID patients). Lymphocyte populations were dominated by T cells; B cells were scarce except in lymphoid follicles in CVID patients with nodular lymphoid hyperplasia. Patients with CVID and XLAG manifest a spectrum of abnormalities in the gastrointestinal tract, with patterns superficially resembling graft-versus-host disease, inflammatory bowel disease, and Whipple's disease, but often lacking some of the diagnostic features of the diseases. Many of the CVID patients with chronic gastrointestinal complaints (62%) also had evidence of autoimmune phenomena, suggesting that in some patients the inflammatory process in the gastrointestinal tract has an autoimmune component.

[Autoimmune enteropathy]

Autoimmune enteropathy was initially described in young male infants presenting as severe secretory diarrhea. The disease is characterized by an inflammatory reaction which may involve several organs (bowel, pancreas, thyroid, kidneys, liver) with the presence of various circulating antibodies. The disease may also be observed in older children and in females with usually less bowel involvement. In view of the autoimmune basis of the disease, treatment requires immunosuppressive agents in addition to parenteral nutrition.

Intractable diarrhea of infancy with epithelial and basement membrane abnormalities

We describe a form of intractable diarrhea in six children (four girls) with similar clinical histories and identical histopathologic features. The children had watery diarrhea of neonatal onset requiring total parenteral nutrition. Two had siblings who had died of diarrhea in the first year of life; two others are sisters. Repeated duodenal or jejunal biopsies revealed villous atrophy with normal or hyperplastic and regenerative cryptae, normal cellularity of the lamina mesenterii propria, and no signs of T-cell activation. The main histologic features are epithelial dysplasia with focal crowding and disorganization of the surface enterocytes, pseudocystic formation of the glands, and abnormal regenerative cryptae. The basement membrane components were studied with polyclonal antibodies on frozen specimens, and were compared with biopsy specimens from patients with celiac disease or autoimmune enteropathy. Relative to the control subjects, there was faint and irregular deposition of laminin at the epithelium-lamina mesenterii propria interface, whereas deposits of heparan sulfate proteoglycan were large and lamellar. The primary or secondary nature of these modifications of the basement membrane remains to be determined, but the modifications might be related to epithelial abnormalities and to the severity of this neonatal diarrhea, which resisted all treatment and necessitated permanent total parenteral nutrition.

Familial autoimmune enteropathy with circulating anti-bullous pemphigoid antibodies and chronic autoimmune hepatitis

In a family of four children (two boys and two girls), the two brothers had severe, protracted watery diarrhea beginning at 2 and 3 weeks of life, respectively. Duodenal mucosa in both patients showed total villous atrophy and severe inflammatory infiltration of the entire bowel. The first patient also had lymphoid cell infiltration of the pancreas and died at 6 weeks of age. The second boy is alive at 2 years of age and is immunocompetent, but still receives total parenteral nutrition. Indirect immunofluorescence studies revealed circulating antibodies to enterocytes, smooth muscle, thyroid, and islet cells. Bullous pemphigoid antibodies (230 and 180 kd), specific for hemidesmosomal proteins and usually associated with a subepidermal blistering skin disease, were detected by direct and indirect immunofluorescence studies and by Western immunoblot. A diagnosis of autoimmune hepatitis was made, based on evidence of chronic active hepatitis and circulating anti-smooth muscle antibody. Immunosuppressive treatments induced partial clinical remission of the diarrhea but no resolution of the small bowel injury. At 16 months of age, remission of the diarrhea occurred, but persistent autoimmune hepatitis led us to maintain treatment with prednisone and azathioprine, and later with cyclosporine. In this child, as in other patients with autoimmune disease, the link between autoantibodies and organ damage remains uncertain but immunosuppressive treatment is indicated.

Response to autoimmune enteropathy to cyclosporin A therapy

Small bowel enteropathies that are associated with an autoimmune process are often resistant to treatment. Two children with autoimmune enteropathy were treated with cyclosporin A for eight months. Both improved, as assessed by growth, small intestinal mucosal morphology, and carbohydrate absorption. Cyclosporin A is useful in the treatment of autoimmune enteropathy. This report also suggests that T cell activation (which is suppressed by cyclosporin A) is important in the pathogenesis of this condition.