Coeliac disease

Tricks of the trade: How to avoid histological pitfalls in celiac disease

Currently, the diagnosis of celiac disease (CD) is based upon the combination of raised serum anti-tissue transglutaminase or anti-endomysial antibodies and the presence of histological alterations of variable degree in the duodenal mucosa. Interpretation of duodenal biopsies is subjected to a number of variables, and the lack of standardization may cause diagnostic controversy or even misdiagnosis. The aim of this overview is to solicit a standardization of the procedures of biopsy taking, orientation, processing, staining and interpretation in order to avoid or minimize misinterpretation of duodenal biopsies. Based on a literature review and extensive personal experience, the appropriate methodology of duodenal biopsy taking, orientation, fixation, processing, staining and interpretation was thoroughly reviewed, and the most common and relevant errors and artifacts were identified. To maximize the diagnostic yield of duodenal biopsy in CD, multiple specimens are best taken from different sites of the duodenum during endoscopy, and careful visual inspection of the duodenal mucosa may help identify abnormalities related to villous atrophy. Biopsy handling and orientation are of utmost importance to avoid artifacts that may impair the pathologist's ability to detect pathology and normality. Immunostaining with anti-CD3 monoclonal antibody should be carried out, and a simplified histological classification may help distinguish atrophic from non-atrophic stages of CD enteropathy. Meticulous attention to biopsy orientation, handling and processing - together with the knowledge of the most common histological artifacts - is necessary to avoid a wrong histological interpretation which, in turn, may lead to misdiagnosis in CD.

A migraine as initial presentation of celiac disease

Celiac disease (CD), also known as gluten-sensitive enteropathy, is a prevalent auto-immune disorder. The silent form of CD seems to be more frequent than expected. CD has been associated with neurologic and psychiatric disorders, notably cerebellar ataxia, peripheral neuropathy, epilepsy, dementia and depression. Migraine is a rare complication of CD. We report a case of CD revealed by a migraine. Apparently no case of celiac disease revealed by migraine has been reported in the literature.

Spectrum of gluten-related disorders: consensus on new nomenclature and classification

A decade ago celiac disease was considered extremely rare outside Europe and, therefore, was almost completely ignored by health care professionals. In only 10 years, key milestones have moved celiac disease from obscurity into the popular spotlight worldwide. Now we are observing another interesting phenomenon that is generating great confusion among health care professionals. The number of individuals embracing a gluten-free diet (GFD) appears much higher than the projected number of celiac disease patients, fueling a global market of gluten-free products approaching $2.5 billion (US) in global sales in 2010. This trend is supported by the notion that, along with celiac disease, other conditions related to the ingestion of gluten have emerged as health care concerns. This review will summarize our current knowledge about the three main forms of gluten reactions: allergic (wheat allergy), autoimmune (celiac disease, dermatitis herpetiformis and gluten ataxia) and possibly immune-mediated (gluten sensitivity), and also outline pathogenic, clinical and epidemiological differences and propose new nomenclature and classifications.

Accuracy of diagnostic antibody tests for coeliac disease in children: summary of an evidence report

OBJECTIVE

The aim of this study was to summarise the evidence from 2004 to September 2009 on the performance of laboratory-based serological and point of care (POC) tests for diagnosing coeliac disease (CD) in children using histology as reference standard.

PATIENTS AND METHODS

We searched MEDLINE and EMBASE for studies reporting on children for tests based on IgA and IgG anti-gliadin (AGA), endomysial (EmA), anti-transglutaminase-2 (TG2), and anti-deamidated gliadin peptides (DGP) antibodies or POC tests. For inclusion, histological analysis of duodenal biopsies and sensitivity and specificity for index tests had to be reported. Data were pooled and summary measures calculated for sensitivity, specificity, positive and negative likelihood ratios ("LR+", "LR-"), and diagnostic odds ratios (DOR). In case of elevated statistical heterogeneity, studies reaching 90% sensitivity or specificity were reported.

RESULTS

A total of 2510 articles were reviewed; 16 entered meta-analysis, reporting on 3110 patients (1876 with CD, 1234 without CD). For IgA-EmA, sensitivity was ≥90% in 7/11 studies and pooled specificity 98.2%. For IgA-anti-TG2, 11/15 studies yielded sensitivities ≥90% and 13/15 specificities ≥90%. For IgA-DGP, sensitivity ranged between 80.7% and 95.1% (specificity 86.3%-93.1%); for IgG-DGP between 80.1% and 98.6% (specificity 86.0-96.9%). IgA-EmA had the highest pooled DOR (554) and LR+ (31.8) for a laboratory test, followed by IgA-anti-TG2, IgG-DGP, IgA-DGP and IgA-AGA. POC tests showed a pooled sensitivity of 96.4% for IgA-TG2 (specificity 97.7%).

CONCLUSIONS

IgA-EmA and IgA-anti-TG2 tests appear highly accurate to diagnose CD. IgG-anti-DGP tests may help in excluding CD. IgA-AGA and IgA-DGP tests show inferior accuracy. POC tests may achieve high accuracy in the hands of experienced readers, but IgA-anti-TG2/EmA were superior.

European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the diagnosis of coeliac disease

OBJECTIVE

Diagnostic criteria for coeliac disease (CD) from the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) were published in 1990. Since then, the autoantigen in CD, tissue transglutaminase, has been identified; the perception of CD has changed from that of a rather uncommon enteropathy to a common multiorgan disease strongly dependent on the haplotypes human leukocyte antigen (HLA)-DQ2 and HLA-DQ8; and CD-specific antibody tests have improved.

METHODS

A panel of 17 experts defined CD and developed new diagnostic criteria based on the Delphi process. Two groups of patients were defined with different diagnostic approaches to diagnose CD: children with symptoms suggestive of CD (group 1) and asymptomatic children at increased risk for CD (group 2). The 2004 National Institutes of Health/Agency for Healthcare Research and Quality report and a systematic literature search on antibody tests for CD in paediatric patients covering the years 2004 to 2009 was the basis for the evidence-based recommendations on CD-specific antibody testing.

RESULTS

In group 1, the diagnosis of CD is based on symptoms, positive serology, and histology that is consistent with CD. If immunoglobulin A anti-tissue transglutaminase type 2 antibody titers are high (>10 times the upper limit of normal), then the option is to diagnose CD without duodenal biopsies by applying a strict protocol with further laboratory tests. In group 2, the diagnosis of CD is based on positive serology and histology. HLA-DQ2 and HLA-DQ8 testing is valuable because CD is unlikely if both haplotypes are negative.

CONCLUSIONS

The aim of the new guidelines was to achieve a high diagnostic accuracy and to reduce the burden for patients and their families. The performance of these guidelines in clinical practice should be evaluated prospectively.

Update on celiac disease - etiology, differential diagnosis, drug targets, and management advances

Celiac disease (CD) is an immune-mediated enteropathy triggered by exposure to wheat gluten and similar proteins found in rye and barley that affects genetically susceptible persons. This immune-mediated enteropathy is characterized by villous atrophy, intraepithelial lymphocytosis, and crypt hyperplasia. Once thought a disease that largely presented with malnourished children, the wide spectrum of disease activity is now better recognized and this has resulted in a shift in the presenting symptoms of most patients with CD. New advances in testing, both serologic and endoscopic, have dramatically increased the detection and diagnosis of CD. While the gluten-free diet is still the only treatment for CD, recent investigations have explored alternative approaches, including the use of altered nonimmunogenic wheat variants, enzymatic degradation of gluten, tissue transglutaminase inhibitors, induction of tolerance, and peptides to restore integrity to intestinal tight junctions.

Clinical value of duodenal biopsies--beyond the diagnosis of coeliac disease

At upper gastrointestinal endoscopy to investigate unexplained diarrhea and iron deficiency anemia, duodenal biopsies are often taken to exclude a diagnosis of coeliac disease. While histology remains the gold standard for this diagnosis, recent developments in serological testing may overtake this as a first line test and biopsy restricted to confirming the diagnosis. Established coeliac disease on biopsy is straightforward, but early lesions may pose a challenge. Newer endoscopic procedures such as push-pull enteroscopy (balloon enteroscopy) with biopsy allow access to the small bowel beyond the second part of the duodenum. Controversy remains as to what constitutes the normal histology of the duodenum, and small bowel. Lymphocytic duodenosis (increased intraepithelial lymphocytes with normal villous architecture) in patients with negative coeliac serology can be associated with Helicobacter pylori, drugs, autoimmune and other diseases including food allergy. Full thickness small intestinal biopsies can aid in investigation of enteric neuropathies in severe dysmotility disorders. Biopsies are also taken to investigate malabsorption due to suspected infectious and metabolic disorders. Despite highly active anti-retroviral therapy (HAART), immunosuppressed patients may be affected by duodenal pathogens. The histology of duodenal mucosa in acid related disorders reflects the damage seen at endoscopy. Although the prevalence of duodenal ulcer disease is decreasing, drugs causing ulceration remain an important disease entity. Recent observations in functional bowel disorders suggest that the duodenum may be a key site for pathology. In functional dyspepsia, patients with early satiety may have excess eosinophil infiltration, and the mast cell is probably a key player in the irritable syndrome in the small intestine.

Gastrointestinal Foxp3 expression in normal, inflammatory and neoplastic conditions

BACKGROUND

Foxp3(+) regulatory T lymphocytes (T-regs) represent an important regulatory cell subset in inflammatory, preneoplastic and neoplastic conditions of the gastrointestinal tract.

METHODS

Inflammatory, preneoplastic and neoplastic conditions of the gastrointestinal tract (189 cases) were studied with the evaluation of Foxp3 regulatory T cells based on immunohistochemistry.

RESULTS

Few Foxp3(+) cells were found in controls and inflammatory conditions (oesophagitis, gastritis, coeliac disease, inflammatory bowel disease); in preneoplastic and neoplastic conditions the number of Foxp3(+) cells was significatively increased.

CONCLUSIONS

In normal conditions the number of mucosal lymphocytes is very low throughout the gastro-intestinal tract; in active coeliac disease patients or on a gluten-free diet, only a slight increase in Foxp3(+) cells may be found. Gastrointestinal cancers are associated with higher Foxp3(+) cell proportion, compared with microscopically normal tissue and with precancerous conditions. However, it is uncertain whether the increase in these regulatory cells is a cause or a consequence of tumour progression.

Is hyperhomocysteinemia relevant in patients with celiac disease?

AIM

To investigate whether this might be related to the presence of hyperhomocysteinemia.

METHODS

From January 1998 to December 2008, we evaluated the presence of hyperhomocysteinemia in a series of 165 adult celiac disease (CD) patients (138 females and 27 males, mean age 43 years).

RESULTS

Hyperhomocysteinemia was evident in 32 patients (19.3%), although most of them had moderate levels (mean value 25 mcg/ml; range 15-30). Only one patient had a history of myocardial infarction (heterozygosis for N5-N10-metil tetrahydrofolate reductase mutation).

CONCLUSION

The systematic assessment of hyperhomocysteinemia seems, at present, unjustified in CD patients.

New screening tests enrich anti-transglutaminase results and support a highly sensitive two-test based strategy for celiac disease diagnosis

BACKGROUND

The identification of specific serological algorithms allowing the diagnosis of celiac disease (CD) is a new challenge for both the clinic and the laboratory. We compared the diagnostic accuracy of three new tests proposed for CD screening with that of the well established IgA tTG, and ascertained whether any combination of these tools might enhance accuracy in diagnosing CD.

METHODS

In sera from 329 CD and 374 control children, the following were assayed: IgA tTG; IgA/IgG, which identify tTG-gliadin complexes (Aeskulisa Celi Check and CeliCheck IgGA); IgA/IgG, which identify deamidated gliadin peptides and tTG (QUANTA Lite(TM) h-tTG/DGP Screen).

RESULTS

When specificity was set at 100%, the most sensitive index of CD was IgA tTG (75.7%, cut-off=100U), followed by QUANTA Lite(TM) h-tTG/DGP Screen (65.3%, cut-off 145U), Aeskulisa Celi Check (62.6%, cut-off 909U/mL) and CeliCheck IgGA (59.6%, cut-off 977U/mL). Three algorithms were obtained by combining IgA tTG with each of the new tests. The algorithm obtained by measuring IgA tTG and QUANTA Lite(TM) h-tTG/DGP Screen allowed the correct identification of CD in 78.7% of cases (negative predictive value=97.3%).

CONCLUSIONS

The two-test based strategy could be used for the cost effective diagnosis of CD.

Automated Marsh-like classification of celiac disease in children using local texture operators

Automated classification of duodenal texture patches with histological ground truth in case of pediatric celiac disease is proposed. The classical focus of classification in this context is a two-class problem: mucosa affected by celiac disease and unaffected duodenal tissue. We extend this focus and apply classification according to a modified Marsh scheme into four classes. In addition to other techniques used previously for classification of endoscopic imagery, we apply local binary pattern (LBP) operators and propose two new operator types, one of which adapts to the different properties of wavelet transform subbands. The achieved results are promising in that operators based on LBP turn out to achieve better results compared to many other texture classification techniques as used in earlier work. Specifically, the proposed wavelet-based LBP scheme achieved the best overall accuracy of all feature extraction techniques considered in the two-class case and was among the best in the four-class scheme. Results also show that a classification into four classes is feasible in principle however when compared to the two-class case we note that there is still room for improvement due to various reasons discussed.

Celiac disease associated with recurrent Guillain Barre syndrome

Celiac disease is associated with multiple extraintestinal presentations, including bone disease, endocrine disorders and neurological deficits. We report a 9 year old girl with celiac disease presenting with recurrent Guillain Barre syndrome (third episode). There was no other clinical manifestation except for refractory iron deficiency anemia. Molecular mimicry explaining the association between these two disorders, is far more interesting.

Coeliac disease: the histology report

To this day intestinal biopsy is justly considered the "gold standard" for the diagnosis of coeliac disease (CD). The aim of the authors in setting up these guidelines was to assist pathologists in formulating a more precise morphological evaluation of a duodenal biopsy in the light of clinical and laboratory data, to prepare histological samples with correctly oriented biopsies and in the differential diagnosis with other pathological entities and complications of the disease. A further intention was to promote the conviction for the need of a close collaborative relationship between different specialists namely the concept of a "multidisciplinary team".

Duodenal villous atrophy: a cause of chronic diarrhea after solid-organ transplantation

Persistent diarrhea is commonly observed after solid organ transplantation (SOT). A few cases of mycophenolate mofetil (MMF)-induced duodenal villous atrophy (DVA) have been previously reported in kidney-transplant patients with chronic diarrhea. Herein, we report on the incidence and characteristics of DVA in SOT patients with chronic diarrhea. One hundred thirty-two SOT patients with chronic diarrhea underwent an oesophago-gastroduodenoscopy (OGD) and a duodenal biopsy after classical causes of diarrhea have been ruled out. DVA was diagnosed in 21 patients (15.9%). It was attributed to mycophenolic acid (MPA) therapy in 18 patients (85.7%) (MMF [n = 14] and enteric-coated mycophenolate sodium [n = 4]). MPA withdrawal or dose reduction resulted in diarrhea cessation. The incidence of DVA was significantly higher in patients with chronic diarrhea receiving MPA compared to those who did not (24.6% vs. 5.1%, p = 0.003). DVA was attributed to a Giardia lamblia parasitic infection in two patients (9.5%) and the remaining case was attributed to azathioprine. In these three patients, diarrhea ceased after metronidazole therapy or azathioprine dose reduction. In conclusion, DVA is a frequent cause of chronic diarrhea in SOT recipients. MPA therapy is the most frequent cause of DVA. An OGD should be proposed to all transplant recipients who present with persistent diarrhea.

Celiac disease: diagnostic criteria in progress

Until a few years ago, celiac disease (CD) was thought to be a rare food intolerance that was confined to childhood and characterized by severe malabsorption and flat intestinal mucosa. Currently, CD is regarded as an autoimmune disorder that is common in the general population (affecting 1 in 100 individuals), with possible onset at any age and with many possible presentations. The identification of CD is challenging because it can begin not only with diarrhea and weight loss but also with atypical gastrointestinal (constipation and recurrent abdominal pain) and extra-intestinal symptoms (anemia, raised transaminases, osteoporosis, recurrent miscarriages, aphthous stomatitis and associated autoimmune disorders), or it could be completely symptomless. Over the last 20 years, the diagnostic accuracy of serology for CD has progressively increased with the development of highly reliable tests, such as the detection of IgA tissue transglutaminase and antiendomysial and IgG antideamidated gliadin peptide antibodies. The routine use of antibody markers has allowed researchers to discover a very high number of 'borderline' cases, characterized by positive serology and mild intestinal lesions or normal small intestine architecture, which can be classified as potential CD. Therefore, it is evident that the 'old celiac disease' with flat mucosa is only a part of the spectrum of CD. It is possible that serology could identify CD in its early stages, before the appearance of severe intestinal damage. In cases with a positive serology but with mild or absent intestinal lesions, the detection of HLA-DQ2 and HLA-DQ8 can help reinforce or exclude the diagnosis of gluten sensitivity.

Morphometric evaluation of duodenal biopsies in celiac disease

OBJECTIVES

The Marsh classification is a semiquantitative method for the diagnosis and monitoring of changes in duodenal biopsies in celiac disease. We have explored the possibility that quantitative changes in villous area and crypt length (morphometry) may provide better information on changes in duodenal morphology, particularly after the introduction of a gluten-free diet.

METHODS

We measured villous height, apical and basal villous widths, and crypt length in 57 adults with celiac disease and 83 control subjects. Villous area was calculated as a trapezoid approximation. Serial changes in villous area and crypt length were determined at regular intervals for up to 4 years after the introduction of a gluten-free diet. Morphometric changes were also correlated with Marsh grade, self-reported adherence to a gluten-free diet, and changes in celiac serology.

RESULTS

The gluten-free diet resulted in a progressive increase in villous area and a progressive decrease in crypt length. Morphometric improvement reached a plateau after 6-12 months with mean villous area attaining a value approximately half that of control subjects. Morphometric data were more sensitive than Marsh grade. Improvement in morphometric indices was significantly associated with the disappearance of anti-endomysial IgA antibody but not with dietary compliance.

CONCLUSIONS

Morphometry is a sensitive way to document changes in duodenal biopsies in celiac disease. In adults treated with a gluten-free diet, it is uncommon for villous area to return to values observed in control subjects, but morphometric improvement is associated with the disappearance of anti-endomysial IgA antibody.

An update in the diagnosis of coeliac disease

Coeliac disease is increasing in prevalence, which is currently estimated at one in 100 of the population and may occur de novo in adults. The diagnosis requires a joint clinicopathological approach; the recommended first-line test is serology with immunoglobulin A (IgA) tissue transglutaminase and IgA endomysial antibodies. These serological tests show high levels of sensitivity and specificity, but biopsy is the gold standard to confirm the diagnosis. It is important that both tests are performed before the introduction of a gluten-free diet. Although the classical histopathology changes of coeliac disease with partial or total villous atrophy are well recognized, the pathology classification of coeliac disease is changing, with recognition that coeliac disease may show minimal pathology (normal architecture and an intraepithelial lymphocyte count/100 enterocytes ≥ 25). This entity is also described as lymphocytic duodenosis, and recommendation of follow-up serology testing is paramount in this condition. Follow-up of patients with coeliac disease is warranted, as normal serology does not predict mucosal recovery. Failure to heal predicts risk of progression to refractory coeliac disease and malignancies. Refractory coeliac disease occurs in 1-2% of patients and this diagnosis requires a combined clinical and histopathology approach with immunocytochemistry.

How patchy is patchy villous atrophy?: distribution pattern of histological lesions in the duodenum of children with celiac disease

OBJECTIVES

In celiac disease (CD) the degree of histological damage in the duodenum may vary, but there is some controversy about the coexistence of villous atrophy and normal mucosa in different biopsy sites, i.e., patchy villous atrophy. We prospectively evaluated the degree, frequency, and distribution of histological lesions among different duodenal sites as well as within each duodenal biopsy.

METHODS

Over the last 4 years, in each patient with suspected CD (positive anti-transglutaminase antibodies), four to five endoscopic biopsies were taken from the duodeno-jejunal flexure/distal duodenum (D3), intermediate duodenum (D2), proximal duodenum (D1), and duodenal bulb (B). Biopsies were subjected to hematoxylin/eosin staining and immunostaining with anti-CD3 monoclonal antibodies for intraepithelial lymphocyte (IEL) count. Duodenal lesions were classified according to Marsh-Oberhuber, and CD was diagnosed according to the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition criteria.

RESULTS

Six hundred and eighty-six children did have CD. A degree of villous atrophy was found in 660/686 patients (96.2%), total villous atrophy was present in 550/686 (80.1%), and 320/686 (46.6%) had different lesions at different sites, but none of these patients had entirely normal biopsies. In all, 116 of 686 (16.9%) had variable lesions within the same biopsy, with grade 2+3A being the most frequent association (43%), followed by 2+3A+3B (27%) and 2+3A+3B+3C (22%). All these 116 patients also had histologically normal areas within the same biopsy, but anti-CD3 immunostaining showed that IELs were always increased in such areas. In all the cases, the severity of duodenal lesions significantly increased in an aborad manner (chi(2)=52.38 with alpha=0.01 and d.f.=12; P<0.0001). No correlation was found between type and distribution of histologic lesions and clinical presentation of CD.

CONCLUSIONS

In newly diagnosed CD, some variability of histological lesions can be found, even within the same duodenal biopsy, in which areas of apparently normal mucosa with increased IEL number often exist. We also confirm our previous findings that duodenal lesions may vary among different biopsies; lesion severity has a proximal-to-distal gradient, but no patient has entirely normal duodenal biopsies. The awareness of such histological variability may help establish a correct diagnosis of CD.

Gluten-sensitive enteropathy (celiac disease): controversies in diagnosis and classification

CONTEXT

Celiac disease, or gluten-sensitive enteropathy, is a chronic inflammatory disorder of the small intestine characterized by malabsorption after ingestion of gluten in individuals with a certain genetic background. Clinical presentation can vary from full-blown malabsorption to subtle and atypical symptoms. Diagnosis currently relies on clinicopathologic studies including mucosal biopsy, serologic tests, and the effects of a diet free of gluten on the symptoms. Mucosal pathologic features are also variable, ranging from mild abnormalities, including intraepithelial lymphocytosis, to completely flat mucosa. Since patients with minimal histologic lesion of intraepithelial lymphocytosis often present with normal serologic findings, biopsy diagnosis becomes more important for identifying such individuals. Classification of mucosal pathology in gluten-sensitive enteropathy has been a subject of controversy among pathologists and needs to be revised according to the current understanding of the disease.

OBJECTIVES

To highlight the variations in clinical and pathologic presentation of gluten-sensitive enteropathy, to emphasize the importance of small-intestinal biopsy evaluation in the diagnosis, and to propose a new classification of mucosal pathology in gluten-sensitive enteropathy, in an effort to overcome the problems related to the classification systems currently available.

DATA SOURCES

A review of the literature on clinicopathologic features and the morphologic spectrum of gluten-sensitive enteropathy is presented.

CONCLUSIONS

Considering that there are many entities in the differential diagnosis of gluten-sensitive enteropathy, because of the varied clinicopathologic spectrum of the disease, diagnosis depends on good clinicopathologic communication. The classification that is presented in this review is a simple and practical approach to improve clinicopathologic correlation in gluten-sensitive enteropathy.

Detection of celiac disease and lymphocytic enteropathy by parallel serology and histopathology in a population-based study

BACKGROUND & AIMS

Although serologic analysis is used in diagnosis of celiac disease, histopathology is considered most reliable. We performed a prospective study to determine the clinical, pathologic, and serologic spectrum of celiac disease in a general population (Kalixanda study).

METHODS

A random sample of an adult general population (n = 1000) was analyzed by upper endoscopy, duodenal biopsy, and serologic analysis of tissue transglutaminase (tTg) levels; endomysial antibody (EMA) levels were analyzed in samples that were tTg+. The cut off values for diagnosis of celiac disease were villous atrophy with 40 intraepithelial lymphocytes (IELs)/100 enterocytes (ECs).

RESULTS

Samples from 33 subjects were tTg+, and 16 were EMA+. Histologic analysis identified 7 of 1000 subjects (0.7%) with celiac disease; all were tTg+, and 6 of 7 were EMA+. Another 26 subjects were tTg+ (7/26 EMA+). This was addressed by a second quantitative pathology study (nested case control design) using a threshold of 25 IELS/100 ECs. In this analysis, all 13 samples that were tTg+ and EMA+ had > or =25 IELs/100 ECs. In total, 16 subjects (1.6%) had serologic and histologic evidence of gluten-sensitive enteropathy. IELs were quantified in duodenal biopsy samples from seronegative individuals (n = 500); 19 (3.8%) had >25 IELs and lymphocytic duodenosis.

CONCLUSIONS

Measurement of > or =25 IELs/100 ECs correlated with serologic indicators of celiac disease; a higher IEL threshold could miss 50% of cases. Quantification of tTg is a sensitive test for celiac disease; diagnosis can be confirmed by observation of > or =25 IELs/100ECs in duodenal biopsy specimens. Lymphocytic enteropathy (celiac disease and lymphocytic duodenosis) is common in the population (5.4%).

Old and new serological tests for celiac disease screening

Evaluation of: Lewis NR, Scott BB. Meta-analysis: deamidated gliadin peptide (DGP) antibody and tissue transglutaminase (tTG) antibody compared as screening test for celiac disease. Aliment. Pharmacol. Ther. 31(1), 73-81 (2010). In celiac disease (CD), deamidation of gliadin peptides, induced by tissue transglutaminase (tTG), generates novel antigenic epitopes evoking a specific immune response. Serological tests based on the detection of antibodies to deamidated gliadin peptides (DGP) have been developed with very promising results in terms of sensitivity and specificity for CD screening. In the present study, a meta-analysis of studies published from 1998 to 2008 was designed to compare the performance of DGP antibodies with that of tTG antibodies, the validated and routinely employed test for CD screening. The authors have limited their analysis to IgA class antibodies underlining that most of the considered studies had methodological imperfections, especially ascertainment bias. The results of this meta-analysis indicated that the pooled sensitivities for DGP and tTG antibodies were 87.8% (95% CI: 85.6-89.9) and 93% (95% CI: 91.2-94.5), respectively, and the pooled specificities were 94.1% (95%CI: 92.5-95.5) and 96.5% (95% CI: 95.2-97.5), respectively. In summary, although both tests represent a very good tool for identifying celiac patients, tTG antibodies display a higher predictive value than DGP antibodies, and must still be considered the best serological test for CD screening.

Influence of previously ingested wheat on fasting breath hydrogen in celiac patients

The excretion of hydrogen in breath commonly persists, despite an overnight fast. Although the elevation of hydrogen concentration above the fasting value after the administration of a test sugar is evidence of malabsorption, the level of the fasting value itself in untreated celiac patients is unknown. Therefore, we studied the fasting breath hydrogen (FBH(2)) concentration in 40 healthy controls, 35 subjects with functional bowel disorders, and 30 patients of untreated celiac disease with and without bread or wheat diet one day before the test. The fasting level of hydrogen concentration in untreated celiac patients (28.7 +/- 19.5 ppm) was significantly higher than those in healthy volunteers (9.5 +/- 3.4 ppm) and subjects with functional bowel disorders (10.6 +/- 4.5 ppm). The percentage of patients with elevated H(2) fasting levels in untreated celiac disease (82.5%) was significantly higher than that in healthy controls (10%) and subjects with functional bowel disorders (17.1%). In 30 celiac patients, studied with and without wheat-free diet one day before the test, the fasting hydrogen levels decreased from 28.7 +/- 19.5 ppm to 10.6 +/- 3.5 ppm, and becoming normal in all patients of celiac disease. Our results show that the patients of untreated celiac disease should be instructed not to eat things made up of wheat one day before hydrogen breath testing so that the normal fasting hydrogen concentration can be obtained and false-negative hydrogen breath test results can be avoided.

Recent advances in coeliac disease

PURPOSE OF REVIEW

Worldwide awareness of coeliac disease in all ages continues to grow. This article aims to summarize critically the recent research advances in coeliac disease.

RECENT FINDINGS

Large multicentre studies have provided further evidence of the role of environmental and nonhuman leucocyte antigen genetic factors in coeliac disease. Siblings of coeliac patients carry a high risk, but those found to have negative coeliac serology are very unlikely to develop the disease. Advances in the efficacy of serological antibody testing potentiate the possibility of future accurate screening programmes in the community. Adherence to a gluten-free diet remains paramount as the recognition of coeliac related complications increases.

SUMMARY

Despite the encouraging progress that has taken place in our genetic and immunological knowledge of coeliac disease, early introduction of a gluten-free diet remains the cornerstone of treatment. Alternatives, however, aimed at altering the toxicity of cereal proteins are now looking more promising.

Is this really celiac disease? Pitfalls in diagnosis

Celiac disease (CD) is an autoimmune enteropathy triggered in susceptible individuals by ingestion of gliadin-containing grains. Although the autoimmune process targets mainly the intestinal mucosa, CD can manifest itself with a variety signs and symptoms affecting any organ or tissue. For many years, CD has been underdiagnosed because of poor awareness. However, studies showing a high prevalence of CD in North America, followed by a consensus conference on CD organized by the National Institutes of Health, have fueled a campaign to raise awareness among subspecialists and primary physicians. Nevertheless, guidelines for the diagnosis of CD remain poorly appreciated and many health care professionals remain confused about its proper management. This review is intended to clarify "facts and fantasies" about CD diagnosis.

Is serum citrulline measurement clinically useful in coeliac disease?

Citrulline (CIT), a non-protein amino acid in circulating blood, is almost exclusively contained in the enterocytes of small bowel mucosa and may represent a reliable marker of functioning enterocyte mass. The aim of this study was to evaluate the clinical utility of measuring serum citrulline levels in a group of patients affected by coeliac disease (CD). Fifty healthy volunteers, 21 patients with untreated coeliac disease and 6 patients with refractory coeliac disease took part in the study. Serum citrulline levels and duodenal lesions were evaluated at the time of diagnosis, and after at least 24 months of gluten-free diet. Serum citrulline concentrations were determined by ion exchange chromatography. In comparison to healthy volunteers, serum citrulline concentrations were significantly lower in untreated and refractory coeliac disease patients. No significant difference was found between untreated and refractory coeliac disease patients and between patients with different patterns of clinical presentation or various degrees of duodenal lesions. After a gluten-free diet, the mean of serum citrulline concentration was increased in all but one patient. Although, as expected, serum citrulline levels turned out to be low in coeliac disease, the clinical utility of their measurement is, at least, questionable in this condition.

IgA endomysium antibodies--an early predictor for celiac disease in children without villous atrophy

AIM

To evaluate possible differences between children with anti-endomysium antibodies (EMA) positivity and normal small bowel mucosa and children with positive EMA and an enteropathy diagnosed as celiac disease (CD).

METHODS

Children with suspected CD and positive EMA (>or=1/10) undergoing small bowel biopsy during 1996 to 2002, were investigated (n=133). Data registered were: year and month of birth, timing of the first biopsy, sex, heredity for CD, dermatitis herpetiformis and diabetes mellitus and outcome of the anti-gliadin antibody test (AGA). The case group, with EMA positivity and normal histology (n=39; 59% female, mean age at the first biopsy 7.3 years, range 1.4-16), was compared with the disease control group, with positive EMA and a biopsy suggestive and further on diagnosed as CD (n=94; 56% female; mean age 7.6 years at the first biopsy, range 0.70-17).

RESULTS

AGA positivity and heredity for CD were found to predict the outcome of a pathological jejunal mucosa. Nineteen of the 39 children in the case group were rebiopsied of whom 11 had developed an enteropathy during a follow-up period of 2-7 years (median 4.5 years).

CONCLUSIONS

EMA positivity in the absence of small bowel enteropathy could be a very early predictor for later overt CD, and necessitates further follow-up, especially if the child is AGA positive and there is a family history of CD.

Histopathologic diagnosis of celiac disease in children without clinical evidence of malabsorption

Diverse clinical and pathologic experiences seem to have led to the idea that celiac disease is a spectrum in both categories. Conflicting results emerging from different reports have produced a large amount of confusion on the subject. This article discussed histopathology findings in 10 children with positive autoantibodies for celiac disease but without clinical evidence of malabsorption. The patients were evaluated following a detailed video-endoscopic study sampling the proximal (first and second) and distal (third and fourth) duodenal parts separately and processed apart. The procedure consistently revealed advanced villous atrophy in the proximal duodenal mucosa associated with mild to absent involvement of the distal segments. The data here presented favor the interpretation that (1) the presence of autoantibodies for celiac disease is always associated with mucosal damage, (2) mucosal damage in the absence of malabsorption is always evident in the proximal duodenum, and (3) the mucosal biopsy in search for the telltale damage needs to be done in separate samples of proximal and distal duodenal mucosa. This procedure may result in a better understanding of the dynamics of mucosal damage in celiac disease.

IgA anti-actin antibodies ELISA in coeliac disease: a multicentre study

BACKGROUND

Previous studies have demonstrated that serum anti-actin antibodies are a reliable marker of intestinal damage severity in coeliac disease.

AIMS

To validate in a multicentre study the clinical usefulness of serum IgA anti-actin antibody ELISA and its possible use in monitoring intestinal mucosa lesions during gluten-free diet.

PATIENTS AND METHODS

Four centres recruited 205 newly diagnosed coeliac disease patients with villous atrophy, 80 healthy controls and 81 "disease" controls. Twelve coeliac disease patients on gluten-free diet but with persistent symptoms underwent serum IgA anti-actin antibody assay and intestinal histology evaluation. IgA anti-actin antibody ELISA was performed with a commercial kit. All coeliac disease patients underwent intestinal histology study.

RESULTS

IgA anti-actin antibodies showed a sensitivity of 80% and a specificity of 85% in the diagnosis of coeliac disease patients with villous atrophy. The area under the receiving operator curve for anti-actin antibodies was 0.873 [95% C.I. 0.805-0.899]. Serum anti-actin antibodies values were significantly higher in coeliac disease patients than in healthy or "disease" controls (P<0.0001). Serum anti-actin antibodies were positive in 41 of the 60 coeliac disease patients with mild intestinal histology lesions (69%) and in 123 of the 145 with severe lesions (85.3%) (P<0.05). There was a significant inverse correlation between anti-actin antibody values and the villi/crypts ratio (r=-0.423; P<0.0001). In the 12 coeliac disease patients on gluten-free diet who underwent re-evaluation as they were persistently symptomatic, intestinal histology showed three cases with persistent villous atrophy: all of these were positive for serum anti-actin antibodies ELISA, whereas both serum anti-tTG and EmAs were negative. The other nine patients showed normal intestinal villi and were negative for serum anti-actin antibodies.

CONCLUSIONS

Anti-actin antibodies are a reliable marker of severe intestinal mucosa damage in coeliac disease patients and a simple ELISA technique offers an accurate method for their determination. These antibodies seem to be a very reliable marker of persistent intestinal damage in coeliac disease patients.

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.

Is TCRgamma clonality assay useful to detect early celiac disease?

BACKGROUND

Although histology is considered the gold standard for the diagnosis of celiac disease, the early stages (latent or potential) of this disease are difficult to diagnose, because of the negativity of laboratory tests and the lack of villous atrophy. Thus, markers of early disease are needed.

AIMS

We investigated the possibility to detect latent or potential celiac disease by means of TCRgamma clonality assay in intraepithelial T cells in patients with suspected disease, negative laboratory tests, and an increased number of intraepithelial lymphocytes.

PATIENTS AND METHODS

Duodenal biopsies were obtained from 35 patients with nonspecific duodenitis (controls), 13 latent or potential celiac disease subjects, 28 well-defined celiac patients, and 8 celiac patients in gluten-free diet. Histologic and immunohistochemical quantification of intraepithelial lymphocytes, as well as TCRgamma clonality assay, were carried out in all subjects by means of standard techniques.

RESULTS

Intraepithelial lymphocytes and TCRgamma clonality were significantly increased in potential and defined celiac patients with respect to the controls, even though the increase in TCRgamma clonality was lesser with respect to that of intraepithelial lymphocytes. No significant differences were found concerning this variable between the potential and defined celiac subjects.

CONCLUSIONS

TCRgamma clonality does not represent a marker of early disease. However, it might be useful to help in distinguishing celiac disease from other causes of nonspecific duodenitis.

High prevalence of celiac disease in Brazilian blood donor volunteers based on screening by IgA antitissue transglutaminase antibody

OBJECTIVE

To study the prevalence of celiac disease among blood donor volunteers based on screening by IgA antitissue transglutaminase antibody, followed by a confirmatory small intestine biopsy.

METHODS

The transversal study involved 3000 potential blood donors, residing in the city of Sao Paulo, Brazil. The participants were gender divided into 1500 men and 1500 women, with an average age 34.4+/-10.8 years, and included blood donor volunteers who could be turned down owing to anemia. All participants answered a questionnaire concerning the presence of diarrhea, constipation or abdominal pain during the 3 months before the study. Each participant with human recombinant IgA antitissue transglutaminase antibody level above 10 U/ml was invited to undergo a small intestine biopsy by means of an upper gastrointestinal endoscopy. The presence of villous atrophy and a positive antibody test were suggestive of possible celiac disease.

RESULTS

Antitissue transglutaminase antibody was positive in 1.5% (45/3000) of the study population. Among the antibody-positive group, 21 (46.6%) agreed to have a biopsy performed, and within them the histological pattern of villous atrophy was confirmed in 66.7% (14/21). Consequently, the suggestive prevalence of celiac disease was at the minimum, one per 214 of the potential blood donor volunteers. A significant association was found between celiac disease and the symptoms of diarrhea, constipation and abdominal pain.

CONCLUSIONS

The prevalence of celiac disease in Sao Paulo city is high and comparable to that observed in European countries. It is possible that in Brazil the prevalence of this disease had previously been underestimated.

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.

Helicobacter pylori infection in patients with celiac disease

BACKGROUND AND AIMS

Patients with Helicobacter pylori gastritis are more likely to have increased duodenal intraepithelial lymphocytes (IEL); this can be reversed by H. pylori eradication. We hypothesized that: (1) H. pylori-infected celiac disease (CD) patients could have different clinicopathological features from noninfected subjects; and (2) the histopathological responses to a gluten-free diet could be different in H. pylori-infected and noninfected patients.

METHODS

Duodenal and gastric biopsies obtained from 80 adults with histologically and serologically confirmed CD before and after 12-18 months of a gluten-free diet were retrospectively evaluated. Gastritis was classified and scored according to the Updated Sydney System; duodenal biopsies were classified using both the Marsh-Oberhuber and a simplified classification proposed by our group.

RESULTS

At baseline, 30 patients had H. pylori infection and 50 did not; at follow-up five new infections were detected. Fifteen patients (3 H. pylori-positive and 12 negative) had lymphocytic gastritis. At baseline, a greater proportion of H. pylori-negative patients had severe villous atrophy (p < 0.01), but milder forms were more prevalent in H. pylori-positive patients (p < 0.01). After a gluten-free diet, significant improvement occurred in all duodenal features (p < 0.001), irrespective of H. pylori status; gastric variables did not change, except for lymphocytic, which resolved in 2 infected and 10 noninfected patients.

CONCLUSIONS

The clinical features of CD patients are unrelated to H. pylori gastritis, and a gluten-free diet is equally effective in infected as in uninfected patients. The higher prevalence of milder duodenal lesions in CD patients with H. pylori infection suggests that lymphocytosis induced by H. pylori gastric infection becomes less obvious as profound inflammatory and structural changes alter the mucosal architecture. This study also provides further support for a pathogenetic relationship between CD and lymphocytic gastritis.

An approach to duodenal biopsies

The introduction of endoscopy of the upper digestive tract as a routine diagnostic procedure has increased the number of duodenal biopsy specimens. Consequently, the pathologist is often asked to evaluate them. In this review, a practical approach to the evaluation of a duodenal biopsy specimen is discussed. An overview of the handling of specimens is given and the normal histology and commonly encountered diseases are discussed. Finally, a description of commonly seen infections is provided, together with an algorithmic approach for diagnosis.