Symposium on pathology of the gastrointestinal tract-Part II. Small intestinal biopsy

Opportunities for Improving Biopsy and Non-Biopsy-Based Diagnosis of Celiac Disease

The accumulating data regarding a non-biopsy diagnosis of celiac disease has led to its adoption in certain scenarios, although debate on whether and when to use non-biopsy criteria in clinical practice is ongoing. Despite the growing popularity and evidence basis for a biopsy-free approach to diagnosis in the context of highly elevated serologies, there will continue to be a role for a biopsy in some groups. This review summarizes the current evidence supporting a non-biopsy approach and arguments supporting continued reliance on biopsy, and focuses on opportunities to improve both approaches.

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.

Statement on Best Practices in the Use of Pathology as a Diagnostic Tool for Celiac Disease: A Guide for Clinicians and Pathologists

Small intestinal biopsy interpretation has been the cornerstone for the diagnosis of celiac disease for over 50 years. Despite the existence of sensitive and specific serological tests, duodenal mucosal biopsies continue to be obtained in the vast majority of patients in whom a diagnosis of celiac disease is being considered. The accurate evaluation of these biopsies requires coordination and information sharing between the gastroenterologist, laboratory, and pathologist in order to optimize tissue sampling, preparation and interpretation. This document, a collaboration between the Rodger C. Haggitt Gastrointestinal Pathology Society and the North American Association for the Study of Celiac Disease, is intended to provide clinicians and pathologists with a summary of best practices in the use of endoscopy and biopsy for patients with suspected celiac disease. The authors present a comprehensive and critical appraisal of the literature with respect to the topics of endoscopic findings, best methods for the obtaining biopsies, completing the pathology form and pathologic assessment, including evaluating intraepithelial lymphocytes and villous architecture. A discussion of conditions with overlapping pathologic findings in duodenal mucosal biopsies is presented. In order to provide additional guidance for challenging situations, the authors include an appendix containing practical suggestions. This review may be utilized in interdisciplinary discussions to optimize care for patients with possible celiac disease.

Biopsy Diagnosis of Celiac Disease: The Pathologist's Perspective in Light of Recent Advances

Celiac disease is a common immune-mediated disorder that occurs in individuals with permissive genetics (HLA-DQ2/DQ8 genotype) following exposure to certain wheat proteins. The histopathologic manifestations of small intestinal mucosal injury (villus atrophy, crypt hyperplasia, and intraepithelial lymphocytosis) are well recognized. However, these findings are not specific for celiac disease, because they are observed in other small intestinal disorders. These mimics include common and rare entities, the list of which continues to grow. This article discusses the histopathology and differential diagnosis of celiac disease and provides the pathologist's perspective on biopsy adequacy, evaluation, and reporting in light of current knowledge.

A Prospective Study on the Usefulness of Duodenal Bulb Biopsies in Celiac Disease Diagnosis in Children: Urging Caution

OBJECTIVES

Several recent celiac disease guidelines recommend the acquisition of duodenal bulb biopsies for diagnostics. This is in conflict with previously reported evidence and routine practice from the 1960s onward. We reopened the issue in a prospective multicenter study and used morphometric variables in evaluating the usefulness of bulb biopsies in children. We further sought to establish whether deposits of IgA targeting bulb transglutaminase 2 (TG2) could be of diagnostic help.

METHODS

Diagnoses of celiac disease were based on clinic and distal duodenal histopathology statements. Centralized reading of villous height (VH) to crypt depth (CrD) ratios and IgA deposits was performed on anatomical duodenal bulb specimens. All children participating also underwent routine investigations for other diseases.

RESULTS

Twenty-two children had celiac disease, and another 22 served as non-celiac disease controls. The quality of the anatomical bulb specimens was unsatisfactory for reliable morphometric measurements in 20 out of 44 (45%) patients even after recuttings. All celiac disease patients had VH:CrD<2.0 (mean 0.2) but also 10 out of 13 (77%) non-celiac control patients had an injured bulb mucosal lining (mean 1.3) even up to false-positive "flat lesion". Bulb IgA deposits were able to separate celiac disease from disease controls.

CONCLUSIONS

Morphological injury is common in the anatomical bulb even without celiac disease, increasing the risk of false-positive diagnoses. Premature conclusions might have been drawn on current care guidelines as to celiac disease diagnosis based solely on anatomical bulb specimens. Bulb mucosal IgA targeting TG2 in poor quality biopsy specimens is a powerful clinical tool in finding celiac disease patients.

Detection of adult celiac disease with duodenal screening biopsies over a 30-year period

BACKGROUND

Serological studies suggest that celiac disease may be present in approximately 0.5% to 1% of the North American population. Screening data based on small intestinal biopsy performed during routine endoscopic evaluations are not available.

METHODS

Patients referred between January 1982 and December 2011 for evaluation of gastrointestinal symptoms and requiring elective investigative upper endoscopic evaluation underwent duodenal biopsies to determine whether changes of adult celiac disease were present.

RESULTS

A total of 9665 patients, including 4008 (41.5%) males and 5657 (68.5%) females, underwent elective endoscopies and duodenal biopsies. Of these, 234 (2.4%) exhibited changes of celiac disease including 73 males (1.8%) and 161 females (2.8%). During the first 20 years, the number of biopsy-positive patients in five-year intervals progressively decreased and, subsequently, during the next 10 years, the number progressively increased.

CONCLUSIONS

Celiac disease is far more common in specialist practice than has been suggested in the evaluation of healthy populations using serological screening studies. Endoscopic duodenal biopsy is an important method of identifying underlying celiac disease and should be routinely considered in all patients undergoing an elective endoscopic evaluation. Noninherited factors, possibly environmental, may play a role in the appearance of biopsy-defined celiac disease and alter detection over time.

Correlation between IgA tissue transglutaminase antibody ratio and histological finding in celiac disease

OBJECTIVES

Positivity of both immunoglobulin A anti-tissue transglutaminase (TTG) and anti-endomysium antibodies (EMA) has a positive predictive value of nearly 100% for celiac disease (CD). The objective of the present study was to evaluate whether patients of any age, with high pretest probability of CD and high titre of anti-TTG and EMA positivity, have a high probability of intestinal damage and may not require the biopsy for final diagnosis.

METHODS

A retrospective analysis of 412 consecutively referred patients, age range 10 months to 72 years, who underwent small-bowel biopsy for suspicion of CD and positivity to both anti-TTG and EMA, was performed at 4 Italian centers. Biopsies were evaluated independently by 2 pathologists using Marsh modified classification; in cases of dissimilar results, a third pathologist examined the biopsy. The final histological finding diagnosis was expressed as the prevalent or highest score assigned by the pathologist board.

RESULTS

Three hundred ninety-six patients (96.1%) had histological findings consistent with CD (grade 2 and 3a, 3b, or 3c of modified Marsh classification). An anti-TTG ratio ≥ 7 was able to identify with the 3 assays used (Celikey, anti-TTG immunoglobulin A, EuTTG) all of the patients with significant mucosal damage (Marsh ≥ 2) independent of age and sex; specificity and positive predictive value were 100%. An anti-TTG ratio >20 was more specific (99.8%) for identification of patients with villous atrophy (Marsh 3 a, b, or c).

CONCLUSIONS

Patients with positivity of anti-TTG ≥ 7-fold cutoff, confirmed by positivity to EMA, have a high-degree probability of duodenal damage. In selected conditions, a duodenal biopsy may be avoided and a confirmed greatly positive anti-TTG result could be the basis to prescribe a gluten-free diet.

Collagenous sprue

Collagenous sprue is a small bowel mucosal lesion that has been historically associated with persistent diarrhea, progressive weight loss and severe malabsorption causing multiple nutrient deficiencies. A severe to variably severe mucosal lesion with distinct subepithelial collagen deposits occurs. Celiac disease has been intimately linked to collagenous sprue and, similar to celiac disease, small bowel ulceration, perforation and lymphoma may complicate the clinical course of collagenous sprue. In collagenous sprue, concomitant collagen deposits may also occur in gastric or colonic mucosal sites (or both), indicating that this unusual mucosal process may be very heterogeneous and far more extensive in the intestinal tract than previously appreciated. Moreover, reports of diagnosis during infancy suggest that the natural history of the disorder could be more prolonged than is currently appreciated. Finally, the collagen deposits, per se, may be due to different causes and, in some, even represent a novel paraneoplastic histopathological marker. Future studies are needed to more precisely define molecular and genetic biomarkers that identify homogeneous groups and permit the development of improved treatment strategies for this increasingly recognized disorder.

Update on collagenous sprue

Collagenous sprue has traditionally been defined as a small intestinal mucosal disorder characterized by persistent diarrhea, severe malabsorption with multiple nutrient deficiencies and progressive weight loss. Pathologically, a severe to variably severe “flattened” mucosal biopsy lesion with distinctive sub-epithelial deposits in the lamina propria region is detected. Histochemical stains and ultrastructural studies have confirmed that these deposits contain collagens. Often, an initial diagnosis of celiac disease is considered but no continued response to treatment with a gluten-free diet occurs. Recent reports indicate an intimate relationship between collagenous sprue and celiac disease, sometimes with concomitant T-cell enteropathy. In addition, permanent disappearance of these deposits after resection of a localized colon cancer suggested that this disorder could actually represent a paraneoplastic morphologic marker of an occult malignancy. Studies showing either gastric or colonic involvement (or both) with this unusual collagenous inflammatory mucosal process may also reflect a far more extensive and heterogeneous process than previously appreciated.

Microscopic enteritis: novel prospect in coeliac disease clinical and immuno-histogenesis. Evolution in diagnostic and treatment strategies

The diagnosis of coeliac disease has traditionally depended on symptoms and intestinal biopsies; nowadays, the diagnosis has been expanded to include an array of serological markers and subtle microscopic lesions. The most important advance in classifying mucosal lesions in coeliac disease was forwarded by Marsh (1992), who provided the biological explanation of how the small bowel reacts to a variety of environmental antigenic challenges including gluten. In the modified version of this classification (Arnhem 1998-1999) autoantibodies have integrated into Marsh's histopathological scheme. As a large part of the coeliac 'iceberg' remains unrecognised, the difficulties in diagnosis continue to challenge clinicians and researchers. Advances in immuno-histochemistry and discovery of the other sensitive markers have acquainted us with so-called Microscopic enteritis, the distinctive subtle abnormalities behind the atypical gluten sensitivity symptoms that often remain unrecognised. Current diagnostic pathways do not always include facilities for looking for this common histological feature in atypical cases. This is essential since improving of the detection rate has been shown to be directly proportional to recognition of cases with milder or minimal mucosal abnormalities. In this revision, we will define and characterise microscopic enteritis as the entity behind a wide range of unexplained gastrointestinal symptoms. Screening for this subtle and distinctive presentation in small bowel pathology will open a new prospect in recognising the most common but unrecognised atypical forms of symptomatic gluten related enteropathies.

Selected luminal mucosal complications of adult celiac disease

Celiac disease is a gluten-dependent intestinal disorder that appears to be associated with several clinical conditions. Some involve the luminal mucosa of the stomach and intestinal tract and may, occasionally, complicate the course of celiac disease. Collagenous colitis has been associated with celiac disease and may lead to chronic diarrhea. Conversely, some of these clinical disorders that involve the luminal mucosa of the stomach and intestine may represent the initial clinical presentation of celiac disease. These disorders should be considered in patients with celiac disease who develop recurrent or refractory symptoms despite adherence to a strict gluten-free diet. Detection of collagenous disorders that affect the luminal mucosa of the stomach or intestinal tract may result in recognition of underlying celiac disease.

"Give us this day our daily bread"--evolving concepts in celiac sprue

CONTEXT

Celiac sprue affects genetically susceptible individuals, who develop small intestinal injury and malabsorption following dietary exposure to gluten. The histologic features are nonspecific but characteristic.

OBJECTIVES

To outline the histologic features of celiac sprue and the necessary clinical context to permit a diagnosis of celiac sprue, to assist the pathologist to identify artifactual biopsy changes that may mimic sprue, to define the differential diagnosis for conditions with a similar histology, and to review historic investigations of this disease.

DATA SOURCES

Sources include the historic experiments and clinical work of members of the Gastroenterology Division of the Department of Medicine and experiences with gastrointestinal pathology consultation material at the University of Washington, Seattle, with reference to selected peer-reviewed articles.

CONCLUSIONS

Confirmation of a diagnosis of celiac sprue is 2-fold: first, biopsy evidence of a characteristic, but nonspecific, pattern of injury including villous blunting or flattening, surface enterocyte damage, and increased intraepithelial lymphocytes; and second, dramatic clinical response to a gluten-free diet. Complete gluten removal from the diet is effective treatment for patients with symptoms of malabsorption; however, lifelong adherence to the diet is expensive, socially limiting, and nearly impossible on a contemporary diet with manufactured foodstuffs. Therefore, pathologists should avoid overdiagnosis of celiac disease based on minimal, nonspecific histologic changes.

Determining IgA and IgG antigliadin, IgA antitransglutaminase, and antiendomysial antibodies in monkey esophagus and in umbilical cord for diagnosis of celiac disease in developing countries

OBJECTIVES

To assess the efficiency of determining IgA and IgG antigliadin antibodies (IgA- and IgG-AGA, respectively), antitransglutaminase (TgA), and anti-endomysial antibodies (AEA) in human umbilical cord (CO) and monkey esophagus for diagnosis of celiac disease; to determine the correlation between serological markers and celiac disease.

PATIENTS AND METHODS

A total of 400 patients were divided in 3 groups: group 1 with 37 patients with celiac disease, group 2 with 208 patients with no enteropathies, and group 3 with 155 patients with other enteropathies. IgA-AGA, IgG-AGA, and TgA were assessed using enzyme-linked immunosorbent assay, whereas AEA was evaluated by indirect immunofluorescence.

RESULTS

Sensitivity and specificity of IgA-AGA were 81.1% and 95.2%, of IgG-AGA 89.2% and 95.2%, of TgA 83.9% and 96.8%, of AEA-CO 87.9% and 100%, and of AEA of monkey esophagus 88.6% and 100%, respectively. Positive predictive values were 75.0%, 76.7%, 83.9%, and 100%. Negative predictive values were 96.6%, 98.0%, 96.8%, and 97.7% for IgA-AGA, IgG-AGA, TgA, and AEA, respectively. Multivariate analysis showed a strong association between AEA-CO and celiac disease and a good correlation with other markers (TgA, IgA-AGA, and IgG-AGA).

CONCLUSIONS

TgA has been recommended for screening patients with celiac disease. Considering the similar sensitivity and specificity of IgA-AGA and TgA and their correlations in the multivariate analysis, both are applicable for this purpose. However, because TgA tests are highly costly and celiac disease is associated with IgA deficiency, the determination of IgA-AGA and IgG-AGA, followed by AEA-CO, is suitable for screening in developing countries, provided a cutoff point for these examinations is established. The results of antiendomysial antibodies in umbilical cord overlapped those in monkey esophagus. Therefore, umbilical cord should be used as a substrate instead of specimens from endangered species.

Comparison of the interobserver reproducibility with different histologic criteria used in celiac disease

BACKGROUND & AIMS

The Marsh-Oberhuber classification of duodenojejunal mucosal lesions is currently used for celiac disease. A more simplified classification, which is based on 3 villous morphologies (A, non-atrophic; B1, atrophic, villous-crypt ratio <3:1; B2, atrophic, villi no longer detectable) and an intraepithelial lymphocyte count of >25/100 enterocytes, has recently been proposed. The aim of the study was to asses the interobserver agreement between different pathologists in classifying celiac disease lesions according to both Marsh-Oberhuber and the new classification system.

METHODS

Sixty patients were selected for the study: 10 subjects without celiac disease, 13 celiac patients with normal villi but a pathologic increase in intraepithelial lymphocytes >25/100 and hyperplastic crypts, and 37 patients with celiac disease with villous atrophy. Sixty slides were sent to 6 pathologists, who were blinded to each other and were not given any clinical information. Each pathologist received the set of biopsy specimens on 2 separate occasions and had to evaluate them according to both grading systems in a random order. The kappa statistic was used to assess agreement between each pair of pathologists.

RESULTS

Overall, mean kappa values were 0.35 (fair) for the Marsh-Oberhuber classification versus 0.55 (moderate) for the new classification system.

CONCLUSIONS

The new classification for duodenal pathology in celiac disease gives better interobserver agreement compared with the more cumbersome Marsh-Oberhuber classification and contributes to the validity of diagnosis in celiac disease.

Adequate oral threonine is critical for mucin production and gut function in neonatal piglets

In previous experiments, we found that the threonine requirement of neonatal piglets fed parenterally was 40% of that when fed intragastrically; we hypothesized that much of the oral supply of threonine is being used for mucin production. To investigate this hypothesis, intragastrically fed 2-day-old piglets were fed one of three treatments for 8 days: 1) a threonine-adequate diet (IG-A; 0.6 g threonine.kg(-1).day(-1) fed intragastrically); 2) a threonine-deficient diet (IG-D; 0.1 g threonine.kg(-1).day(-1) fed intragastrically); or 3) a threonine-deficient diet with adequate threonine delivered parenterally (IV-A; 0.5 g threonine.kg(-1).day(-1) fed parenterally plus 0.1 g threonine.kg(-1).day(-1) fed intragastrically). IG-D piglets experienced higher nitrogen excretion, higher plasma urea, and lower plasma threonine concentrations versus both of the other groups (P < 0.05), indicating profound threonine deficiency. Mucosal mass and total crude mucin content were lower in the colons of IG-D pigs (P < 0.05). Histopathological analysis showed lower numbers of acidic mucin-producing goblet cells in the duodenum and ileum of IG-D pigs. In IG-D pigs, acidic mucin subtypes were lower in the small intestine but higher in the colon, which corresponded with persistent diarrhea. The parenteral supply of threonine was adequate to maintain most outcome parameters, although IV-A pigs did have smaller colonic goblet cells with more acidic mucins compared with IG-A pigs. Overall, our results suggest that adequate dietary threonine was critical in the production of mucus and that a parenteral threonine supply can ameliorate most of the symptoms of oral threonine deficiency.

Coeliac disease: an update for pathologists

Coeliac disease is the manifestation of an immune hypersensitivity reaction towards gluten and related proteins, in genetically predisposed people. Although the precise pathogenesis of this condition remains to be fully elucidated, it is probably multifactorial in origin. The diagnosis of coeliac disease has traditionally depended on intestinal biopsies alone; nowadays, the diagnosis has been expanded to include an array of serological markers. This review is intended to offer pathologists an update of the relevant history and immunopathology pertaining to coeliac disease and also to offer recommendations on the ongoing responsibilities of the pathologist in the diagnosis and reporting of coeliac disease.

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.

Collagenous mucosal inflammatory diseases of the gastrointestinal tract

Collagenous mucosal inflammatory diseases involve the columnar-lined gastric and intestinal mucosa and have become recognized increasingly as a significant cause of symptomatic morbidity, particularly in middle-aged and elderly women, especially with watery diarrhea. Still, mechanisms involved in the pathogenesis of this diarrhea remain poorly understood and require further elucidation. The prognosis and long-term outcome of these disorders has been documented only to a limited extent. Recent clinical and pathologic studies have indicated that collagenous mucosal inflammatory disease is a more extensive pathologic process that concomitantly may involve several sites in the gastric and intestinal mucosa. The dominant pathologic lesion is a distinct subepithelial hyaline-like deposit that has histochemical and ultrastructural features of collagen overlying a microscopically defined inflammatory process. An intimate relationship with other autoimmune connective tissue disorders is evident, particularly celiac disease. This is intriguing because these collagenous disorders have not been shown to be gluten dependent. Collagenous mucosal inflammatory disorders may represent a relatively unique but generalized inflammatory response to a multitude of causes, including celiac disease, along with a diverse group of pharmacologic agents. Some recent reports have documented treatment success but histopathologic reversal has been more difficult to substantiate owing to the focal, sometimes extensive nature, of this pathologic process.

Evidence for increased apoptosis of duodenal intraepithelial lymphocytes in cow's milk sensitive enteropathy

OBJECTIVES

Enterocyte apoptosis induced by activated intraepithelial lymphocytes (IELs) is increased in celiac disease (CD). A lesser increment in intraepithelial lymphocytes associated with normal villous structure is also characteristic of cow's milk sensitive enteropathy (CMSE), but no information is available about the apoptosis rate of this condition.

METHODS

Endoscopic biopsy samples of 21 children with untreated CMSE were compared with samples from 15 children with CD and 18 controls. Apoptosis was analyzed using the TUNEL technique and the M30 antibody from duodenal bulb and mid-duodenum samples. Ki-67 was used to detect the proliferation rate and CD3(+) to count the overall number of T lymphocytes.

RESULTS

In the mid-duodenum, CMSE patients showed a significantly increased intraepithelial and lamina propria density of TUNEL(+) cells, but no difference in the density of M30(+) epithelial cells was seen compared with controls. In CD subjects, TUNEL(+) counts in mid-duodenal villous epithelium were increased. CD3(+) intraepithelial lymphocytes were increased in both CMSE and CD and correlated with TUNEL(+) and M30(+) counts among all patients. No increase in proliferation rate was seen in CMSE, and no significant correlations between apoptosis and proliferation rates were detected.

CONCLUSIONS

The observed increase in TUNEL(+) counts and the absence of any increase in M30(+) cells suggest that the apoptosis rate of intraepithelial lymphocytes, but not of enterocytes, is increased in the small IELs in CMSE. However, the number of intraepithelial lymphocytes is still elevated in CMSE, indicating that a disturbance of homeostasis of intraepithelial lymphocytes is important in its pathogenesis.

Lymphoid nodular hyperplasia and cow's milk hypersensitivity in children with chronic constipation

OBJECTIVE

To investigate the incidence of cow's milk allergy as evidenced by milk challenge and the findings of endoscopic and immunohistochemical examinations in children with chronic and refractory constipation.

STUDY DESIGN

Thirty-five study subjects (mean age, 8.3 +/- 3.3 years; range, 3-15 years; 17 girls) and 15 control subjects (mean age, 11.7 +/- 3.2 years; range, 2-15 years; 9 girls) were studied by colonoscopy and a 4-week cow's milk elimination and challenge.

RESULTS

Lymphoid nodular hyperplasia was the most prominent endoscopic finding in half of the subjects (46%), mostly occurring patchily in the transverse colon. Histologic findings other than lymphoid accumulation and mildly increased density of eosinophils were few. During the milk elimination and with supportive medication, 83% of subjects remitted. Constipation and/or other gastrointestinal or skin symptoms relapsed only in one third (34%) during the cow's milk challenge, these having significantly higher densities of intraepithelial gammadelta + T cells ( P <.001) in the biopsy samples of the terminal ileum as compared with the control subjects.

CONCLUSIONS

We were able to find formal evidence for the presence of cow's milk allergy in children with chronic constipation.

The significance of routine duodenal biopsies in pediatric patients undergoing upper intestinal endoscopy

GOALS

To determine the significance of performing routine duodenal biopsies during upper intestinal endoscopy in a pediatric population and to evaluate their contribution to the overall diagnosis.

BACKGROUND

Performing duodenal biopsy during every upper endoscopy regardless of the indication for endoscopy and the macroscopic findings, is a controversial topic. Advocates of performing routine biopsies argue that unexpected pathology such as villous atrophy, may have significant clinical implications. Opponents argue that the yield of performing a biopsy on an apparently normal mucosa is low.

STUDY

Duodenal biopsies, routinely taken from 201 pediatric patients during upper endoscopy over a 26-month period were retrospectively reviewed. Duodenal biopsies taken during this period for suspected mucosal lesions were not included in the analysis. Indications for endoscopy included suspected peptic disease, gastroesophageal reflux, unexplained vomiting, abdominal pain, iron deficiency anemia and Crohn disease.

RESULTS

Of the 201 sets of biopsies reviewed, 159 (79.1%) were normal, 7 had insufficient material for evaluation and 35 (17.4%) carried abnormalities that included: 10 Giardia lamblia (4.9%), 13 mild chronic inflammation (6.5%), and 8 increased intraepithelial lymphocytes (3.9%). Two biopsies showed mixed acute and chronic inflammation, 1 showed lymphatic dilatation and 1 had a mild mucosal lesion. The risk for microscopic pathology in the duodenum was higher when Helicobacter pylori was present in the gastric biopsy (25.98% vs. 12.16% P < 0.02). The negative predictive value of a normal appearing duodenal mucosa was 81.5%, implying that a normal appearing mucosa does not rule out pathology. No complications were encountered in our series.

CONCLUSION

We suggest that the inclusion of routine duodenal biopsies as part of upper endoscopy in pediatric patients should be considered favorably. This practice may yield additional pathologic findings that otherwise could have been missed. It should be done regardless of the indication for endoscopy or the gross appearance of the mucosa. This practice does not increase the risk of the procedure.

The role of esophagogastroduodenoscopy in the diagnosis and management of upper gastrointestinal disorders

Esophagogastroduodenoscopy has revolutionized the clinical management of upper gastrointestinal diseases. Millions of EGDs are performed annually in the United States for many indications, such as gastrointestinal bleeding, abdominal pain, dysphagia, or surveillance of premalignant lesions. Esophagogastroduodenoscopy is very safe, with a low risk of serious complications such as perforation, cardiopulmonary arrest, or aspiration pneumonia. It is a highly sensitive and specific diagnostic test, especially when combined with endoscopic biopsy. Esophagogastroduodenoscopy is increasingly being used therapeutically to avoid surgery. New endoscopic technology such as endosonography, endoscopic sewing, and the endoscopic videocapsule will undoubtedly extend the frontiers and increase the indications for endoscopy.

Current understanding of food allergy

IgE-mediated hypersensitivity reactions account for the majority of well-documented food allergy reactions, but non-IgE-mediated immune mechanisms do cause some hypersensitivity disorders. A variety of gastrointestinal, cutaneous, respiratory, and generalized symptoms and syndromes have been associated with IgE-mediated food allergy. The diagnostic approach to adverse food reactions begins with a careful medical history and physical examination. Laboratory studies may then be used appropriately in the evaluation. Once the diagnosis of food allergy is established, the only proven therapy is the strict elimination of the food from the patient's diet. Studies in both children and adults indicate that symptomatic reactivity to food allergens is often lost over time, except possibly reactions to peanuts, tree nuts, and seafood.

The histopathology of pediatric celiac disease: order must prevail out of chaos

The role of histopathology for diagnosing celiac disease (CD) has been recently challenged. However, based in our experience with roughly 4,600 distal duodenal and jejunal biopsies in children it is apparent that appropriate biopsy site, handling, processing, and microscopic evaluation result in a consistent pattern of microscopic changes which allows strong clinical-pathologic correlation. A simple way for establishing the villous/crypt (V/C) ratio is proposed. Normal mucosa displays a V/C ratio of 2.5 or more. Villous atrophy is then graded according to the V/C ratio as follows: Grade 1: 2.5-2; Grade 2: 1-2; Grade 3: 1-0.5, and Grade 4: less than 0.5. The grading should be done in areas of the biopsy where at least 2 to 3 crypts are present in almost its full length. CD disease was consistently associated with villous atrophy grades 3 and 4, which fully recovered or maintained Grade 1 after gluten-free diet. Grade 2 biopsies were rare and related to incomplete gluten-free diet. Patchy lesions were never seen as were patients with normal biopsies later developing mucosal atrophy. Histopathologic evaluation of mucosal biopsies to rule out CD requires adequate biopsy site (distal duodenum or proximal jejunum), and proper handling (oriented material), processing (cutting on edge) and interpretation. The proposed villous atrophy grading may help to adequately compare experiences from different centers as well as to reconcile apparent different findings in separate biopsies. In children histopathology keeps on having a central role for CD diagnosis.

Treatment of giardiasis reverses "active" coeliac disease to "latent" coeliac disease

In patients with coeliac disease, a regression of intestinal damage without a gluten-free diet is a very rare event. We describe a young child with diarrhoea, intestinal mucosa atrophy and positive serum anti-endomysial and anti-tissue transglutaminase (anti-tTG) antibodies during intestinal giardiasis infection. He showed normal intestinal mucosa architecture and negative anti-endomysial and anti-tTG antibodies after his giardiasis was cured, although he continued to assume a normal diet. Re-evaluations on a 6-monthly basis showed that he was symptom free, and all haemato-chemical parameters were within normal limits. Three years after the initial diagnosis, a third intestinal biopsy showed: normal mucosa architecture; an increase in the intra-epithelial CD3+ and gamma/delta+ lymphocyte counts; and immunoglobulin-A anti-endomysial antibody detection in the supernatant of the intestinal mucosa culture incubated with gliadin. An active coeliac disease status, with intestinal mucosa atrophy, may regress to a latent coeliac disease status with normal intestinal mucosa histology after removal of the environmental factors that have presumably precipitated mucosa damage. Serum anti-endomysial and anti-tTG antibody behaviour is not a permanent, life-long feature and this must recommend the repetition of anti-endomysial or anti-tTG antibody assays in the same patient whenever coeliac disease diagnosis is again suspected, irrespective of previous negativity.

Defining gluten refractory enteropathy

OBJECTIVE

The diagnosis of coeliac disease (CD) is based on the responsiveness of the enteropathy to a gluten-free diet (GFD). This implies that terms such as 'non-responsive CD' and 'refractory CD' are almost paradoxical. In spite of this, these terms are commonly used in the literature, often with different and confusing meanings.

METHODS

On the basis of both a review of the literature and our clinical experience, we propose the following classification. A condition characterized by a refractory enteropathy, not due to lymphoma, ulcerative jejunoileitis or collagenous sprue, but in which gluten sensitivity has been shown previously or could be shown while the patients were on an immunosuppressive therapy should be indicated as refractory CD. Those patients in whom gluten sensitivity can be excluded should be considered to be affected by non-coeliac refractory sprue. Finally, patients in whom the presence of CD cannot be either confirmed or excluded should be considered to be affected by undefined sprue.

RESULTS

Twenty-four certain refractory patients are described in the literature. The data suggest a diagnosis of refractory CD in 13 patients, non-coeliac refractory sprue in three patients, and undefined sprue in eight patients.

CONCLUSIONS

We define refractory CD as a form of CD that no longer responds to a GFD. Non-coeliac refractory sprue is a condition unrelated to CD. It could be either an independent condition or a common end point of different enteropathies.

Diagnostic approach to the patient with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common chronic functional bowel disorder characterized by abdominal pain or discomfort and alterations in bowel habits. In clinical practice, diagnosis is based on positive symptoms known as the Rome criteria and limited diagnostic screen, taking into account warning features suggestive of organic disease. Minimal diagnostic tests are warranted to rule out structural lesions in a cost-effective manner and to convince the patient of the diagnosis of IBS. An initial diagnosis of IBS is safe and rarely needs revision over time. Persistence of symptoms is to be expected and does not justify suspicion of other diagnoses. Only change in the clinical pattern over time justifies additional investigations. Other diagnostic evaluations depend on predominant symptoms, namely constipation, diarrhea, and pain or discomfort. It should be emphasized that although an initial "positive diagnosis" is safe to exclude other diseases with similar symptoms, a common disorder such as IBS may often coexist with other asymptomatic disorders.

Lymphonodular hyperplasia as a sign of food allergy in children

BACKGROUND

Lymphonodular hyperplasia of the gastrointestinal tract in children is a rare endoscopic finding of uncertain clinical significance. In this study, 12 children with lymphonodular hyperplasia of the duodenum from a series of 63 children were studied for recurrent abdominal pain. Four additional children with lymphonodular hyperplasia of the colon are described. All the patients with lymphonodular hyperplasia were also evaluated for food allergy.

METHODS

A gastroduodenoscopy was performed in the patients with recurrent abdominal pain and in the four in whom lymphonodular hyperplasia of the colon had been diagnosed by colonoscopy. An open oral elimination and challenge test to diagnose food allergies was scheduled for all subjects with lymphonodular hyperplasia or any suspicion of food allergy. The study design also included skin prick tests with common allergens and determination of serum immunoglobulin A and immunoglobulin E concentrations.

RESULTS

Lymphonodular hyperplasia of the duodenal bulb was the main finding in 12 (19%) of the 63 children. The condition was found to be associated with food allergy in nine subjects (75%), which was significantly more often than among the remaining 51, 12 (24%) of whom had food allergy by the same criteria. In an oral challenge, food allergy first manifested gastrointestinal symptoms in the subjects of both groups and, in all except one, on days 2 through 5 after the foodstuffs were administered in minimal doses. In a histologic study, the duodenal specimens revealed significantly more eosinophilic cells in the children with food allergy and lymphonodular hyperplasia than in the children with food allergy but no lymphonodular hyperplasia. The major symptoms in the four patients with lymphonodular hyperplasia of the colon had been anemia and blood in stool in two and abdominal pains with mucous loose stools in the remaining two. Colonoscopic examination showed one to have diffuse and the other three patchy lymphonodular hyperplasia of the colon. In an oral challenge, three reacted to milk and two to cereals.

CONCLUSIONS

Preliminary observations showed that lymphonodular hyperplasia of the duodenum or the colon is related to the gastrointestinal type of food allergy to basic foodstuffs. Further research is needed to define this finding as a separate entity.

Alpha-heavy chain disease, Mediterranean lymphoma, and immunoproliferative small intestinal disease: a review of clinicopathological features, pathogenesis, and differential diagnosis

There are a number of clinical syndromes associated with chronic diarrhea, malabsorption, and lymphoplasmacytic proliferation of the small intestine. In Middle-Eastern and Mediterranean countries immunoproliferative small intestinal disease is endemic, whereas in other parts of the world (including Northwestern Europe and North America) celiac sprue, and other sprue-like syndromes refractory to dietary gluten withdrawal, predominate. All of these syndromes appear to involve chronic stimulation of intestinal mucosa-associated lymphoid tissue and are associated with a heightened risk of malignant transformation. The clinicopathological features of these diseases, and distinction of the Middle Eastern syndromes from those more common in the Western hemisphere, have been reviewed.

Colonic histopathology in untreated celiac sprue or refractory sprue: is it lymphocytic colitis or colonic lymphocytosis?

Colonic histopathology in some patients with untreated celiac sprue and refractory sprue has been said to be indistinguishable from lymphocytic colitis, but there have been no objective comparisons on which this is based. The purpose of this study was to determine the prevalence and to characterize the nature of colonic histopathology at the time of diagnosis in patients with celiac or refractory sprue. Colonoscopic biopsy specimens obtained at the time of diagnosis from 16 patients with celiac sprue, six patients with refractory sprue, nine patients with lymphocytic colitis, and five normal controls were analyzed blindly by histological and morphometric methods, quantitating the number and specific subtypes of inflammatory cells within the lamina propria and epithelium. Immunoperoxidase staining of intraepithelial lymphocytes with a monoclonal antibody to CD8 also was performed. Three of 16 patients with untreated celiac sprue (19%) were thought to have colonic histological abnormalities, which by morphometry consisted of slightly increased numbers of lymphocytes in the surface epithelium and lamina propria, many of which were CD8-positive. These abnormalities were distinguishable from lymphocytic colitis by the lack of increased overall lamina propria cellularity and surface epithelial abnormalities, and by fewer intraepithelial lymphocytes. In refractory sprue, colonic histological abnormalities were more frequent than in celiac sprue, occurring in four of six patients (67%), more pronounced, and identical to those in the lymphocytic colitis syndrome. However, colonic intraepithelial lymphocytes in lymphocytic colitis were mostly CD8-positive, whereas those in the colitis of refractory sprue rarely were. Mild colonic lymphocytosis in patients with untreated celiac sprue should be distinguished from lymphocytic colitis by the lack of surface epithelial abnormalities, the lack of increased cellularity of the lamina propria, and the lack of ongoing watery diarrhea after treatment with a gluten-free diet. In contrast, colonic histopathology in refractory sprue is indistinguishable from lymphocytic colitis, although immunohistochemical differences do exist.

Gastric and esophageal intraepithelial lymphocytes in pediatric celiac disease

Celiac disease (CD) is associated with marked mononuclear cell inflammation in the small intestinal mucosa. This study was performed to evaluate analogous changes in the gastric and esophageal mucosa of pediatric patients with CD, with emphasis on epithelial lymphocytosis. We evaluated intraepithelial lymphocytes (IELs) in 23 gastric (no.IELs/100 epithelial cells) and 14 esophageal mucosal biopsy specimens (IELs/hpf) from 23 pediatric cases of CD and 10 nonceliac matched controls. Four patients had postgluten withdrawal biopsy specimens reviewed, and one of these had further postgluten challenge biopsy specimens evaluated as well. Gastric specimens from the CD cases showed a significantly increased IEL count (20.5 +/- 14.4; range, 4-50) compared to controls (3.4 +/- 1.9; range, 1-8; p < 0.001), which also correlated directly with the histologic severity of the small intestinal disease as assessed by the degree of villous shortening. Sixteen (69.5%) of 23 gastric specimens showed > 8 IELs, which was the highest value obtained in control specimens. The four posttreatment specimens showed a significant reduction in the gastric IEL counts from a mean of 19.8 to 3.5 IELs/100 epithelial cells (p < 0.001). The single case that had a further postgluten challenge biopsy showed a return to the pregluten withdrawal IEL count. However, the degree of gastric intraepithelial lymphocytosis did not correlate with any of the clinical data, such as age, gender, presenting symptoms, or serum antibody levels (antigliadin, antireticulin, or antiendomysium). Furthermore, no differences were observed in the IEL count in CD esophageal specimens (5.3 +/- 2.6; range, 2-10) compared to controls (5.2 +/- 1.5; range, 3-8; p = 0.935). These findings suggest that an immune-mediated lymphocytic response linked to gluten occurs in the gastric epithelium, similar to that seen in the small intestine of pediatric patients with CD. Therefore, gastric intraepithelial lymphocytosis may represent a concurrent manifestation of CD rather than a separate entity in the pediatric population.

Intracellular protozoan infection in small intestinal biopsies of patients with AIDS. Light and electron microscopic evaluation

Small intestinal biopsies of 21 patients with acquired immunodeficiency syndrome (AIDS) with light microscopic findings diagnostic or suspicious for parasite infection were investigated by transmission electron microscopy (TEM). TEM allowed us to identify and specify the genus and species of involved parasites in 16 out of the 21 cases: 7 Cryptosporidium parvum, 5 Enterocytozoon bieneusi and 4 Isospora belli. Cryptosporidium was easily identified on light microscopy (LM), and only slightly influenced by parasite burden in all the 7 cases; TEM confirmed LM diagnosis and made it possible to characterize the parasites as C. parvum. The identification of Microsporidium on LM in our cases was related to the burden of parasite; its presence was certainty identified in 2 cases and suspected in 3. TEM allowed to identify these parasites as E. bieneusi. Intracytoplasmic coccidia could be detected with certainly in semithin sections in all 4 cases, but TEM was always needed to specify the infectious agent as I. belli. In 5 cases the suspicious of protozoan infection on LM (3 microsporidia, 1 intracytoplasmic coccidia and 1 Cryptosporidium) was not confirmed by TEM. Our data suggest that TEM is an appropriate diagnostic tool in this field of pathology and necessary in most of the cases.

Intestinal function and injury in acquired immunodeficiency syndrome-related cryptosporidiosis

BACKGROUND/AIMS

The pathogenesis of the diarrhea in acquired immunodeficiency syndrome (AIDS)-related cryptosporidiosis is not known. The hypothesis of this study was that the intestinal dysfunction and injury are related to the number of organisms infecting the intestinal mucosa. The aim of this study was to study the influence of intensity of infection on intestinal function and injury in AIDS-related cryptosporidiosis.

METHODS

In 16 patients with AIDS with intestinal Cryptosporidium infection, the intensity of infection was quantified by counting the total number of fecal oocysts excreted in 24 hours and by determining the percent of duodenal epithelium covered by organisms. Intestinal function was assessed by vitamin B12 absorption and serum D-xylose test. Intestinal injury was assessed by morphology of duodenal mucosa, differential urinary excretion of lactulose and mannitol, and fecal alpha 1-antitrypsin clearance. Measurements were repeated after treatment with paromomycin.

RESULTS

Vitamin B12 and D-xylose absorption negatively correlated with intensity of infection. Villus atrophy occurred only in patients with oocyst excretion of > 10(8) oocyst/24 hours. Lactulose/mannitol urinary excretion ratio showed a positive correlation with intensity of infection. Intestinal function and injury improved in patients whose oocyst counts were reduced by treatment with paromomycin.

CONCLUSIONS

Cryptosporidium infection in patients with AIDS causes malabsorption and intestinal injury in proportion to the number of organisms infecting the intestine.

Subclinical coeliac disease is a frequent cause of iron-deficiency anaemia

BACKGROUND

Although it is known that anaemia may be the only presenting symptom in coeliac disease, prevalence figures of unsuspected coeliac disease in anaemic patients are not available. The aim of this study was to assess the clinical usefulness of antigliadin and antiendomysial antibody tests in the diagnostic algorithm of anaemic patients.

METHODS

Two hundred consecutive anaemic patients were tested for antigliadin antibodies, and those positive were also tested for antiendomysial antibodies. All patients positive for antigliadin and antiendomysial antibodies underwent intestinal biopsy.

RESULTS

Sixteen patients were antigliadin antibody-positive, and 10 were also antiendomysial antibody-positive. In all 10 a jejunal biopsy was consistent with coeliac disease (prevalence, 5%). This prevalence rose to 8.5% when patients with macrocytic anaemia or with microcytic anaemia due to previous bleeding or responsive to oral iron therapy were excluded from the calculation.

CONCLUSIONS

Coeliac disease is a frequent cause of iron-deficiency anaemia, and antigliadin and antiendomysial antibody tests should be always performed in the diagnostic algorithm of anaemic patients.

Duodenal morphology and intensity of infection in AIDS-related intestinal cryptosporidiosis

BACKGROUND

The pathogenesis of intestinal cryptosporidiosis is not known. Previous studies have shown that the intensity of infection varies between patients. The hypothesis of this study is that intestinal injury is related to the intensity of infection.

METHODS

The histological abnormalities associated with Cryptosporidium infection were evaluated in duodenal biopsy specimens from 18 patients with acquired immunodeficiency syndrome-associated cryptosporidiosis. The intensity of Cryptosporidium infection was assessed histologically in all patients as the percentage of mucosa covered by organisms and by quantitation of oocyst excretion in the stools of 14 patients.

RESULTS

Duodenal biopsy specimens from 13 patients (72%) showed normal villous architecture. In these patients, the inflammatory component of the lamina propria was either normal or moderately increased. This increase consisted mostly of lymphocytes and plasma cells. Five of 18 patients (28%) had flattening of the mucosa associated with a prominent neutrophilic infiltrate. The intensity of infection in patients with villous flattening as measured from biopsy specimens and stool was significantly higher than in those without flattening (92% vs. 12% mucosa occupied with organisms; 738 x 10(3) vs. 199 x 10(3) oocyst/mL stool) (P < 0.004 in both cases).

CONCLUSIONS

Most patients with intestinal Cryptosporidium infection had normal duodenal villous architecture. Severe duodenal morphological abnormalities, including flattening of the villi, were associated with high-intensity infections.

Food allergies in children

Ingested food represents the greatest foreign antigenic load that confronts the human immune system. In most individuals tolerance develops to food antigens that are continually gaining access to the body. When tolerance fails to develop, the immune system may react with a hypersensitivity reaction. Allergies to food affect up to 8% of children less than 3 years of age and 1% to 2% of the general population. Symptoms include the gastrointestinal, cutaneous, and respiratory symptoms, as well as systemic anaphylaxis with shock. Clinical investigations in the past have characterized the food hypersensitivity disorders, but our understanding of the basic immunopathologic mechanism remains incomplete. Current progress in allergen characterization and the rigorous scientific methods now being applied to this field by many investigators provide hope that new information regarding the pathogenesis of these disorders and new forms of therapy will soon become available. For now, practicing physicians must carefully diagnose specific food sensitivities and educate patients and their families in the elimination of the responsible food allergen.