Serologic testing for celiac disease in the United States: results of a multilaboratory comparison study

Novel Therapies for Celiac Disease: A Clinical Review Article

Celiac disease is emerging as an autoimmune disorder with increasing prevalence and incidence. The mean age of presentation is also increasing with the passage of time. The delay in diagnosis is partly attributable to the asymptomatic state in which most patients present. The diagnosis of the disease is primarily based on biopsy, but serology can also be included for possible screening purposes. Although the primary management strategy is to eliminate gluten from the diet of such patients; however, compliance with the diet and follow-up to detect healing might be difficult to maintain. Therefore, there is a need to investigate further management therapies that can be easily administered and monitored. The aim of the review is to discuss the epidemiology, clinical presentation, and novel therapies being investigated for celiac disease.

Diagnostic Value of Immunoglobulin G Anti-Deamidated Gliadin Peptide Antibody for Diagnosis of Pediatric Celiac Disease: A Study from Shiraz, Iran

PURPOSE

Screening serologic tests are important tools for the diagnosis of celiac disease (CD). Immunoglobulin (Ig)G anti-deamidated gliadin peptide (anti-DGP) is a relatively new autoantibody thought to have good diagnostic accuracy, comparable to that of anti-tissue transglutaminase (anti-tTG) antibody.

METHODS

Pediatric patients (n=86) with a clinical suspicion of CD were included. Duodenal biopsy, anti-tTG, and IgG anti-DGP antibody tests were performed. The patients were divided into CD and control groups based on the pathological evaluation of duodenal biopsies. The diagnostic accuracy of serological tests was determined.

RESULTS

IgA anti-tTG and IgG anti-DGP antibodies were positive in 86.3% and 95.4% of patients, respectively. The sensitivity, specificity, and diagnostic accuracy of the IgA anti-tTG test were 86.3%, 50.0%, and 68.6%, respectively, and those of the IgG anti-DGP test were 95.4%, 85.7%, and 90.7%, respectively. The area under the receiver operating characteristic (ROC) curve was 0.84 (95% confidence interval [CI], 0.74-0.91) for IgA anti-tTG test and 0.93 (95% CI, 0.86-0.97) for IgG anti-DGP test. The comparison of IgA anti-tTG and IgG anti-DGP ROC curves showed a higher sensitivity and specificity of the IgG anti-DGP test.

CONCLUSION

IgG anti-DGP is a reliable serological test for CD diagnosis in children. High tTG and DGP titers in the serum are suggestive of severe duodenal atrophy. The combined use of IgA anti-tTG and IgG anti-DGP tests for the initial screening of CD can improve diagnostic sensitivity.

Latitude and Celiac Disease Prevalence: A Meta-Analysis and Meta-Regression

BACKGROUND & AIMS

The latitudinal gradient effect is described for several autoimmune diseases including celiac disease in the United States. However, the association between latitude and global celiac disease prevalence is unknown. We aimed to explore the association between latitude and serology-based celiac disease prevalence through meta-analysis.

METHODS

We searched MEDLINE, Embase, Cochrane, and Scopus databases from their beginning through June 29, 2018, to identify screening studies that targeted a general population sample, used serology-based screening tests, and provided a clear location from which we could assign a latitude. Studies were excluded if sampling was based on symptoms, risk factors, or referral. Study selection and data extraction were performed by independent reviewers. The association measures between latitude and prevalence of serology-based celiac disease were evaluated with random-effects meta-analyses and meta-regression.

RESULTS

Of the identified 4667 unique citations, 128 studies were included, with 155 prevalence estimates representing 40 countries. Celiac disease was more prevalent at the higher latitudes of 51° to 60° (relative risk [RR], 1.62; 95% CI, 1.09-2.38) and 61° to 70° (RR, 2.30; 95% CI, 1.36-3.89) compared with the 41° to 50° reference level. No statistically significant difference was observed at lower latitudes. When latitude was treated as continuous, we found a statistically significant association between CD prevalence and latitude overall in the world (RR, 1.03, 95% CI, 1.01-1.05) and a subregional analysis of Europe (RR, 1.05; 95% CI, 1.02-1.07) and North America (RR, 1.1; 95% CI, 1.0-1.2).

CONCLUSIONS

In this comprehensive review of screening studies, we found that a higher latitude was associated with greater serology-based celiac disease prevalence.

Coeliac disease and the videocapsule: what have we learned till now

Celiac disease is diagnosed in part by finding areas of pathology in the small bowel (SB) mucosa. This can often be difficult because the pathologic alterations, including atrophy of the small intestinal villi, can often be sparse and subtle. Some of the quantitative methods for detecting and measuring the presence of villous atrophy from videocapsule endoscopy (VCE) images are presented and discussed. These methods consist of static features of measurement including texture, gray level, and presence and abundance of fissures contained within each acquired image. The methods also consist of dynamic measurements including spectral analysis, and determining motion from a sequence of endoscopic images as obtained from a VCE clip. Thus far, several methods have been found useful to characterize the SB mucosa of untreated celiac disease patients versus control patients lacking villous atrophy, which have revealed significant differences in texture, frequency, and motion on analysis of VCE. In untreated celiac patients undergoing endoscopy, there tends to be greater magnitude of changes and spatial differences in textural descriptors, longer periodic components, indicating slower periodic activity, and differences in feature location, suggesting alterations in motility at areas of pathology as compared to patients without villous atrophy. Improvements in the quantitative analysis of VCE imaging in celiac patients is important to detect pathology in suspected patients, so that biopsies can be obtained from pertinent regions of the small intestinal mucosa. Improvements are also necessary so that patients with celiac disease can be monitored to evaluate the progress of mucosal healing after onset of treatment.

Duodenal lymphocytosis with no or minimal enteropathy: much ado about nothing?

Duodenal lymphocytosis is a nonspecific finding that is being detected with heightened frequency. Although increased intraepithelial lymphocytosis with normal villous architecture classically corresponds to grade 1 of the Marsh classification, many other conditions have been reported to be associated with this histologic pattern. In this article, we offer a broad review of the associations of isolated increased intraepithelial lymphocytosis with celiac and nonceliac gluten sensitivity, as well as of the broadening nonceliac etiologies.

Diagnosis and management of adult coeliac disease: guidelines from the British Society of Gastroenterology

A multidisciplinary panel of 18 physicians and 3 non-physicians from eight countries (Sweden, UK, Argentina, Australia, Italy, Finland, Norway and the USA) reviewed the literature on diagnosis and management of adult coeliac disease (CD). This paper presents the recommendations of the British Society of Gastroenterology. Areas of controversies were explored through phone meetings and web surveys. Nine working groups examined the following areas of CD diagnosis and management: classification of CD; genetics and immunology; diagnostics; serology and endoscopy; follow-up; gluten-free diet; refractory CD and malignancies; quality of life; novel treatments; patient support; and screening for CD.

Detection of autoantibodies against actin filaments in celiac disease

INTRODUCTION

Serum autoantibodies specifically directed toward intracellular cytoskeletal actin filaments (anti-actin antibodies, AAA) were found to be associated with intestinal villous atrophy (IVA) in celiac disease (CD). The aim of this study was to assess IgA-AAA with a commercial test that uses sections of rat intestinal epithelial cells in a well-selected cohort of patients and to evaluate the relationship between the presence of serum IgA-AAA and the severity of intestinal mucosa damage.

MATERIALS AND METHODS

Serum samples from 70 CD patients and 150 controls subjects were analyzed retrospectively for the presence of IgA-AAA.

RESULTS

The indirect immunofluorescence test that we used has a specificity of 100%; the sensitivity of the test is not high (25.7%). In this study we also show that serum AAA are more frequently positive in CD patients with total IVA (77.8%) and that this association is significant

DISCUSSION

IgA-AAA certainly cannot take the place of much more sensitive tests such as a-tTG and EMA in the diagnosis of CD because of their low sensitivity; nonetheless, these antibodies could be determined in a-tTG and/or EMA positive patients who cannot undergo an intestinal biopsy because of a severe contraindication, or in the case of negative consensus regarding endoscopy, or when the histology interpretation is difficult.

CONCLUSION

In conclusion, the IFI commercial test with intestinal epithelial cells as substrate offers a useful method for IgA-AAA determination. Serum IgA-AAA positivity is indicative of more severe intestinal histology damage and their assay could be a real help to the clinician, especially in the complicated cases.

Is enteroscopy necessary for diagnosis of celiac disease?

Celiac disease (CD) is an autoimmune inflammatory disease of the small intestine as a result of reaction to wheat protein, gluten. Exclusion of dietary gluten is the mainstay of the treatment that necessitates a precise diagnosis of the disease. Serological screening may aid in identifying patients with suspected CD, which should be confirmed by intestinal biopsy. It has been shown that duodenal biopsies are good for detection of the disease in most patients. However, there is a group of patients with positive serology and inconclusive pathology. As a result of the widespread use of serology, many patients with equivocal findings grow quickly. Unfortunately current endoscopic methods can only diagnose villous atrophy, which can be present in the later grades of disease (i.e., Marsh III). To diagnose CD correctly, going deeper in the intestine may be necessary. Enteroscopy can reveal changes in CD in the intestinal mucosa in 10%-17% of cases that have negative histology at initial workup. Invasiveness of the method limits its use. Capsule endoscopy may be a good substitute for enteroscopy. However, both techniques should be reserved for patients with suspected diagnosis of complications. This paper reviews the current literature in terms of the value of enteroscopy for diagnosis of CD.

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%).

Deamidated gliadin peptide antibodies as a routine test for celiac disease: a prospective analysis

GOALS

This study was designed to establish whether deamidated gliadin peptide antibodies (DGP-AGA) could improve the serologic workup for celiac disease (CD).

BACKGROUND

The best serologic approach for CD screening is currently based on the combined detection of tissue transglutaminase (tTGA), endomysial (EmA), and gliadin antibodies (AGA).

STUDY

One hundred forty-four consecutive patients with gastrointestinal and extraintestinal signs suggestive for CD were investigated using serologic tests, that is, IgG and IgA DGP-AGA, IgA tTGA, IgA EmA, and duodenal biopsy.

RESULTS

Forty-eight out of 144 patients (33%) had CD with different severity of villous atrophy. IgA tTGA showed 93.7% sensitivity compared with 91.6% for IgA EmA, 84.3% for IgA DGP-AGA, and 82.3% for IgG DGP-AGA. Of the 3 cases negative for IgA tTGA, IgA EmA, and IgA DGP-AGA, 2 had total IgA deficiency, although both were positive for IgG DGP-AGA. IgG DGP-AGA showed a very high specificity for CD (98.9%), not only superior to IgA DGP-AGA (79.8%), but also to IgA tTGA (96.6%) and very close to IgA EmA (100%).

CONCLUSIONS

Our prospective study shows that the combined search for IgA tTGA and IgG DGP-AGA provides the best diagnostic accuracy for CD, allowing the identification of all CD cases---except one---with a very high specificity. The serologic workup for CD screening could be significantly improved by the routine introduction of IgG DGP-AGA together with IgA tTGA, thus reducing the number of tests and with an obvious advantage in terms of cost-efficacy.

Autoantibody screen in inflammatory myopathies high prevalence of antibodies to gliadin

BACKGROUND

Inflammatory myopathies (IM) are associated with autoimmune diseases.

AIM

To evaluate the titers of auto-antibodies specific to various autoimmune diseases in patients with IM compared with controls.

METHODS

Sera from 99 IM patients and 100 healthy controls were tested for autoantibodies for vasculitis (myeloperoxidase, PR3, and glomerular basement membrane) and autoimmune gastrointestinal diseases (IgA and IgG antigliadin, antitissue transglutaminase, and Saccharomyces cerevisiae) utilizing the BioPlex 2200 Multiplexed Immunoassay method (Biorad).

RESULTS

Antigliadin IgA levels were significantly elevated in IM patients compared with controls (0.37 units +/- 0.44 vs. 0.24 units +/- 0.15, P = 0.017). Antitissue transglutaminase IgA was marginally increased in IM patients versus controls (0.36 units +/- 1.12 vs. 0.2 units +/- 0.0, P = 0.08).

CONCLUSIONS

Antibodies to gliadin and tissue transglutaminase characteristic for celiac disease were elevated in patients with IM compared with controls. This may indicate a higher prevalence of gluten sensitivity or celiac disease in IM.

[Study of celiac disease in adults with type 1 diabetes mellitus]

Celiac disease (CD) presents a wide clinical spectrum. There are asymptomatic or oligosymptomatic forms, which are difficult to diagnose. Since patients with untreated CD can develop severe complications, early diagnosis of these forms is important. Consequently, in groups at risk for CD, such as patients with type 1 diabetes (DM1), screening through determination of antigliadin (AGA), anti-tissue transglutaminase (ATG) and antiendomysial antibodies (EMA) is recommended. In the present study, 463 DM1 patients were screened for these antibodies. Patients who were positive for one or more were offered an upper endoscopy to obtain distal duodenum biopsies. Histological lesions, when present, were classified using Marsh's classification. Of the 463 patients, 62 (13.4%) were positive for at least one of the three antibodies, and 42 accepted to undergo an endoscopy. Fourteen patients (3% of the DM1 patients) were histologically diagnosed with CD. Most of these patients had no symptoms of CD, although some showed laboratory findings frequent in CD. The presence of clinical or analytical data compatible with CD was independent of the grade of histological lesions. Finally, we calculated the sensitivity and positive predictive value for each antibody. The most sensitive were ATG and EMA. Because of the technical simplicity of determining ATG with ELISA, in our opinion, this test should be the option of choice for screening.

Soropositividade para doença celíaca em crianças e adolescentes com baixa estatura

OBJETIVO: Avaliar a frequência da positividade do marcador sorológico para doença celíaca em crianças e adolescentes com baixa estatura, utilizando-se o anticorpo anti-transglutaminase humana como teste de triagem. MÉTODOS: Estudo descritivo com amostra obtida por conveniência. Foi realizado no período de abril a setembro de 2004 no Ambulatório Geral de Pediatria do Instituto Materno Infantil Professor Fernando Figueira e no Ambulatório de Crescimento e Desenvolvimento do Hospital das Clínicas. Foram considerados casos as crianças e os adolescentes portadores de baixa estatura, definida como aquela abaixo do percentil 3 para idade e sexo, utilizando como referência o gráfico de altura/idade do National Center for Health Statistics, 2000. Foi pesquisado o anticorpo anti-transglutaminase humana (AATGh), considerado positivo se concentração >20U/mL e, nos positivos, o anticorpo antiendomísio (AAE). RESULTADOS: Foram avaliados 78 pacientes, sendo 41 (53%) do sexo feminino. O AATGh foi positivo em 3/78 (3,8%) dos pacientes. O AAE foi positivo em um paciente, naquele com concentração mais elevada do AATGh. Considerando-se a positividade para os dois testes, a soropositividade foi de 1,3%. CONCLUSÕES: A presença de marcador sorológico para doença celíaca em crianças e adolescentes portadoras de baixa-estatura e pertencentes a famílias de baixa-renda aponta para a necessidade de investigação sistemática da doença celíaca nesses pacientes.

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.

Usefulness of antibodies to deamidated gliadin peptides in celiac disease diagnosis and follow-up

The prevalence of the recently described deamidated gliadin peptide antibodies was compared with that of the routinely used antigliadin, antiendomysial, and tissue transglutaminase antibodies in the sera of 128 untreated celiac patients and 134 controls. Sensitivity and specificity for celiac disease were 83.6 and 90.3% for IgA and 84.4 and 98.5% for IgG antibodies to deamidated gliadin peptides. The new test displayed higher diagnostic accuracy than antigliadin antibodies and, although less sensitive than antiendomysial and tissue transglutaminase antibodies, showed significantly higher specificity than tissue transglutaminase antibodies (P < 0.001). Persistence of peptide antibodies after gluten withdrawal was an expression of low compliance with the diet and of the lack of improvement of the intestinal mucosa. The combined use of tissue transglutaminase and deamidated gliadin peptide antibodies seems to be a very useful tool for celiac disease diagnosis. Moreover, antibodies to deamidated gliadin peptides can be helpful in disease follow-up.

The liver in celiac disease

Celiac disease is a common (1% prevalence) chronic immune-mediated disorder of the small intestine induced by dietary wheat, barley, and rye. Several hepatic disorders have been described in association with celiac disease. Isolated hypertransaminasemia with nonspecific histologic changes in a liver biopsy is the commonest hepatic presentation of celiac disease. A gluten-free diet normalizes liver enzymes and histologic changes in most patients. Moreover, celiac disease can coexist with autoimmune liver disorders such as autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis. Celiac disease has increasingly been reported with a variety of other liver diseases. Thus, the hepatologist needs to consider celiac disease in the differential of abnormal liver blood tests and to be aware of the clinical implications of this frequent disease in patients with liver disorders. The possible mechanisms of liver injury and those common factors that explain the association of celiac disease with liver disorders are discussed. The aims of this article are (1) to review the spectrum and pathogenesis of liver injury related to celiac disease and (2) to provide direction to those caring for patients with chronic liver diseases regarding the detection and effective treatment of celiac disease.

Nutritional deficiencies in celiac disease

Celiac disease is characterized by small bowel enteropathy, precipitated in genetically susceptible individuals by the ingestion of "gluten," which is a term used to encompass the storage proteins of wheat, rye, and barley. Although the intestine heals with removal of gluten from the diet, the intolerance is permanent and the damage recurs if gluten is reintroduced. This damage causes a wide variety of consequence including maldigestion and malabsorption, resulting in the characteristic, although not universal, features of malnutrition. This article examines recent advances in the understanding of the spectrum of celiac disease, illustrates the impact of celiac disease on nutrition, and describes approaches to the management of the disease.

Serological and clinical comparison of children and adults with anti-endomysial antibodies

We compared serological and clinical presentation of 38 adults (5 males, 33 females) and 37 children (15 boys, 22 girls) with anti-endomysial antibodies (AEA).AEA, antinuclear (ANA), anti-parietal (APA), anti-thyroid microsomal (ATMA), anti-thyreoglobulin (ATGA), anti-smooth muscle (SMA) and anti-mitochondrial (AMA) antibodies were detected by IIF. Anti-tissue transglutaminase (tTG), anti-extractable nuclear antigens (ENA) and anti-actin (AAA) antibodies were studied by ELISA. There were no differences in frequency of ANA, APA, ATGA, SMA, AMA and AAA in children and adults. ATMA (p < 0.001) and anti-ENA (p < 0.05) positivity were more frequently found in adults. Anti-Ro/SSA had 7/38 adults and 1/37 children (p < 0.05). Adults had more frequently silent form of celiac disease associated with autoimmune diseases (p < 0.001). We are the first to demonstrate that in spite of no difference in ANA positivity in adults and children, ANA in adults more frequently target ENA, especially Ro/SSA antigen. The reason for this ANA specificity could be the longer gluten exposure in adults.

Diagnosis of celiac disease

Celiac disease is an immune mediated enteropathy initiated by ingestion of gluten, in genetically susceptible individuals. With changing epidemiology, celiac disease initially thought to affect only Europeans, has been increasingly reported from other parts of the world including India. However, its true prevalence in India is still not known, as the diagnosis is being missed. The gold standards for diagnosis have been characteristic small intestinal mucosal changes on gluten and a full clinical remission on its removal from the diet. Presence of serological antibodies, which disappear on gluten free diet further confirms the diagnosis. The understanding of the histopathology of celiac disease has changed over the years. The small bowel mucosal lesion of celiac disease is an evolutionary process with normal mucosal architecture and an increase in intraepithelial lymphocytes at one end of the spectrum and classical flat mucosa at the other. In the Indian subcontinent celiac disease has a heterogeneous histological presentation and the diagnosis may be missed if it is based only on severe mucosal changes or the serology is not considered when moderate or mild mucosal changes are present. The last two decades have shown that antiendomysical (Anti EMA) and anti tissue transglutaminase antibodies (anti-tTGA) have a sensitivity and specificity of more than 95% to diagnose celiac disease. Anti EMA tests being operator dependent are more liable to errors and anti- tTGA may be preferred for large scale screening. However, the different source of tTGA antigen, varied techniques of production and the use of arbitrary units by different commercial kits can influence the diagnostic accuracy of the anti-tTGA assay. There is a strong genetic association of celiac disease with HLA-DQ2 or DQ8. The presence of HLA-DQ2 hetrodimer in more than 97% of a group of North Indian patients with celiac disease indicates that this population has a similar genetic risk for the disease. HLA DQ2 typing can be used for ruling out celiac disease where the diagnosis is equivocal as it has a negative predictive value of greater than 95%. Given the protean clinical manifestation and the heterogeneous histology a standard algorithm for diagnosis of celiac disease is important.

Intraepithelial lymphocytosis in architecturally preserved proximal small intestinal mucosa: an increasing diagnostic problem with a wide differential diagnosis

CONTEXT

An increased intraepithelial lymphocyte density in an architecturally normal proximal small intestinal mucosal biopsy is a common finding facing surgical pathologists dealing with gastrointestinal biopsy specimens. Approximately 1% to 2% of all proximal small intestinal biopsies will show this change. It is increasingly recognized by surgical pathologists that gluten-sensitive enteropathy is an important cause of this pattern; however, gluten-sensitive enteropathy accounts for the minority of all cases. A wide variety of immunologic stimuli can raise intraepithelial lymphocyte numbers. Among the other common associations are enteric infection, autoimmune disease, drugs, and gastric Helicobacter infection.

OBJECTIVE

To outline the causes of intraepithelial lymphocytosis, to highlight the importance and the difficulties faced in establishing gluten-sensitive enteropathy as the cause, and to aid the surgical pathologist in the routine sign out of these cases.

DATA SOURCES

A review of the literature detailing the causes or associations of proximal small intestinal intraepithelial lymphocytosis is presented.

CONCLUSIONS

Increased lymphocyte numbers in the epithelium of architecturally preserved proximal small intestinal biopsies is a morphologic feature associated with a broad differential diagnosis.

Increasing numbers at a specialist coeliac clinic: contribution of serological testing in primary care

BACKGROUND

Serological testing, using IgA class endomysial and tissue transglutaminase antibodies has high sensitivity and specificity for coeliac disease and allows case finding by clinicians other than gastroenterologists. We reviewed new coeliac patients seen over a 9-year period to determine how the availability of serology, particularly to primary care physicians, has changed rates and sources of diagnosis.

METHODS

Files of patients attending a specialist coeliac clinic who were diagnosed from 1996 through 2004 were reviewed. Patients with villous atrophy consistent with gluten sensitive enteropathy (Marsh III) on duodenal biopsy were selected. Data analysed included clinical characteristics, endomysial and tissue transglutaminase antibodies status and source of request for serology.

RESULTS

Over the study period 347 new coeliac patients, comprising adults and children aged 10 years and over, were identified, of whom 163 (47%) were identified by serological testing in primary care, 152 (44%) at the hospital gastroenterology department and 32 (9%) by other physicians in secondary care. Over three consecutive 3-year periods, the percentage of patients identified in primary care rose from 28% through 47% to 60%, with a rise in total numbers diagnosed from 93 through 118 to 136. There was no change in patient clinical characteristics over the study period. Though tissue transglutaminase antibodies were less sensitive than endomysial antibodies, combined testing obtained a sensitivity of over 90%. Patients identified in primary care were significantly younger and more likely to present with diarrhoea as a primary symptom.

CONCLUSION

Currently over half of our coeliac patients are identified by serological testing in primary care, which has resulted in an overall rise in diagnosis rates. Primary care practitioners have an important role in the diagnosis of coeliac disease, particularly of patients who present with non-gastrointestinal symptoms. The contribution of specialists other than gastroenterologists in secondary care is disappointing and may improve with directed education.

Cribado de la enfermedad celíaca en grupos de riesgo

Several epidemiological studies show that celiac disease with extraintestinal manifestations is 15 times more frequent than celiac disease with intestinal symptoms. Fifteen years ago the iceberg model was proposed to explain the epidemiology of this disease. On the one hand, there are a quantifiable number of patients who are correctly diagnosed since they have symptoms suggestive of this disease and who form the visible part of the iceberg. However, several studies using screening serology demonstrate that for each patient diagnosed, there is a mean of 5-10 patients without a diagnosis. These patients form the submerged part of the iceberg (monosymptomatic or silent celiac disease). The most widely accepted strategy to investigate the submerged part of the "celiac iceberg" is screening of known risk groups through a systematic search for celiac disease in these groups.

Intraepithelial lymphocytes and coeliac disease

The diagnosis of coeliac disease is easy in cases with symptoms and unequivocal small intestinal villous atrophy. However, patients often suffer from only subtle if any symptoms. Borderline villous shortening is common, making the histologic diagnosis difficult. The increase in intraepithelial lymphocytes is typical even in early-stage untreated coeliac disease. Unfortunately, this finding is unspecific. In coeliac disease, the relative density of gammadelta+ intraepithelial lymphocytes is increased. The presence of IgA class anti-endomysium or anti-tissue transglutaminase antibodies clearly increases the likelihood of the disease. Coeliac disease is closely linked to HLA DQ2 and DQ8, and their absence speaks strongly against the condition, whereas a positive finding is virtually of no diagnostic value. In borderline cases, the gluten-dependency of symptoms or mucosal inflammation should be shown by gluten-free diet or gluten challenge. No single test is efficient enough to distinguish unspecific increase in intraepithelial lymphocytes from early coeliac disease; clinical history, histology, serology and gluten-dependency should be taken into account in the diagnostic work-up.

Practical considerations for the identification and follow-up of children with celiac disease

Celiac disease is an immune-mediated enteropathy affecting 0.5% to 1% of children and is induced by dietary gluten in susceptible individuals carrying the human leukocyte antigen DQ2 or DQ8 heterodimer. If serological screening is positive or if a patient displays suggestive symptoms, an endoscopic biopsy of the distal duodenum is required to confirm the diagnosis. Symptoms of celiac disease are often mild or absent. Overt malabsorption occurs in only 2% to 10% of children. Individuals with a higher risk of developing celiac disease, including first-degree relatives of affected patients and children with type I diabetes, Turner syndrome, Williams syndrome or Down syndrome, should be offered screening for celiac disease along with a discussion of the implications. If serological testing is negative, a high index of suspicion should remain if malabsorption, iron deficiency or osteopenia is present. Also, immunoglobulin A deficiency should be excluded. At-risk individuals should undergo serial serological screening. Lifelong adherence to a gluten-free diet is the only treatment. If left untreated, symptomatic children with celiac disease carry an increased risk of developing osteoporosis and have a greater lifetime risk of cancer. The long-term outcome of undiagnosed or untreated asymptomatic individuals is less clear.

Seronegative celiac disease: increased prevalence with lesser degrees of villous atrophy

Our aim was to assess differences in the sensitivities of serologic tests used for the diagnosis of celiac disease among patients with varying degrees of villous atrophy. Among 115 adults with biopsy-proven celiac disease who fulfilled strict criteria, including serologic testing at the time of diagnosis and response to a gluten-free diet, 71% had total villous atrophy and 29% partial villous atrophy. Endomysial antibody was positive in 77% of those with total villous atrophy, compared to 33% with partial villous atrophy (P < 0.001). There was no difference in sensitivity when the type of presentation (classical vs. silent) was compared. Endomysial antibody-positive and negative patients did not differ with respect to age at diagnosis, duration of symptoms, mode of presentation, or family history of celiac disease. All anti-tissue transglutaminase-positive patients had TVA on biopsy. Seronegative celiac disease occurs. Endomysial antibody positivity correlates with more severe villous atrophy and not mode of presentation of celiac disease. Serologic tests, in clinical practice, lack the sensitivity reported in the literature.

Celiac disease serology in irritable bowel syndrome and dyspepsia: a population-based case-control study

OBJECTIVE

To determine whether undiagnosed celiac disease is associated with irritable bowel syndrome (IBS) or dyspepsia in the community.

SUBJECTS AND METHODS

A self-report bowel disease questionnaire was mailed to a random sample of Olmsted County, Minnesota, residents aged 20 to 50 years. All respondents who reported symptoms of dyspepsia or IBS (cases) and all respondents without notable gastrointestinal symptoms (controls) were invited to participate (260 eligible subjects; 150 [58%] were studied). Each respondent was examined by a physician, and the medical records of each were reviewed (3 subjects did not meet the criteria for dyspepsia or IBS at the time of the physician interview). Serum was obtained to measure antiendomysial antibodies and tissue transglutaminase (TTg) IgA antibodies using validated assays.

RESULTS

A total of 34 subjects had dyspepsia (20 had ulcerlike dyspepsia), 50 had IBS (19 had diarrhea-predominant IBS), and 15 met criteria for both dyspepsia and IBS; 78 were asymptomatic healthy controls. The overall prevalence of positive TTg serology was 4% (95% confidence interval [CI], 1.5%-8.5%). The number of subjects who were seropositive for TTg was 2 of 34 (5.9%) with dyspepsia (95% CI, 0.7%-19.7%), 2 of 50 (4.0%) with IBS (95% CI, 0.5%-13.7%), and 2 of 78 (2.6%) of asymptomatic controls (95% CI, 03%-9.0%) (P = .64 IBS vs controls; P = .58 dyspepsia vs controls). No subjects had positive antiendomysial antibodies.

CONCLUSION

In this community, celiac disease did not explain the presence of either IBS or dyspepsia.

Idiopathic chronic cough and organ-specific autoimmune diseases: a case–control study

The marked female predominance in cases of idiopathic chronic cough and its association with mild chronic lymphocytic airway inflammation suggests an underlying autoimmune process. We set out to test the hypothesis that idiopathic chronic cough is associated with other organ-specific autoimmune diseases in a case control study. Twenty-two patients with idiopathic chronic cough and 65 community-matched controls for age and sex who responded to a self-administered questionnaire were asked about the presence of autoimmune disease, other medical problems and drug history. All subjects were invited to have a blood test for an autoimmune screen. Thirteen out of 22 (59%) patients with idiopathic chronic cough and eight out of 65 (12%) age- and sex-matched controls reported organ-specific autoimmune disease (odds ratio 8.8; 95% confidence interval 2.4-31.8, P<0.001). Organ-specific autoantibodies were present in a significantly higher proportion of cases than controls (40% vs. 13%; P = 0.047). These findings suggest a relationship between idiopathic chronic cough and organ-specific autoimmunity.

Significance of intraepithelial lymphocytosis in small bowel biopsy samples with normal mucosal architecture

OBJECTIVES

The aim of this study was to determine the specificity of increase in intraepithelial lymphocytes (IELs) with normal villous architecture in small bowel biopsy samples for diagnosis of gluten sensitivity (GS) and its significance in the absence of GS.

METHODS

Small bowel biopsy samples from 43 patients with increased IELs and no other pathology were reviewed. Patients with prior diagnosis of GS were excluded. A group of 46 patients with normal duodenal biopsy during the same period served as controls. The clinical records of patients and controls were examined for presenting symptoms, laboratory tests, and final clinicopathological diagnosis. Immunohistochemical characterization of IELs was performed in 13 cases.

RESULTS

Four (9.3%) patients had GS based on positive IgA antiendomysial antibodies (n = 3) and favorable response to gluten-free diet (n = 4). One patient (2.2%) had partially treated tropical sprue; six patients (14%) had disorders of immune regulation including Hashimoto's thyroiditis (n = 2) and one case each of Graves' disease, rheumatoid arthritis, psoriasis, and multiple sclerosis; and six patients (14%) were on nonsteroidal anti-inflammatory drugs (NSAIDs). In contrast, none of the control subjects had GS (p = 0.05), tropical sprue, or immunoregulatory disorders (p = 0.011), and one (2.2%) was on NSAIDs (p = 0.04). Increased IELs were also observed in Crohn's disease, lymphocytic/collagenous colitis, and bacterial overgrowth, but the association did not reach statistical significance. Histological features (number and distribution of IELs, crypt mitoses) and immunophenotypic analysis of IELs did not reliably distinguish GS-related from non-GS-related causes of increased IELs.

CONCLUSIONS

Intraepithelial lymphocytosis in an otherwise normal small bowel biopsy is somewhat nonspecific, but in nearly 10% of cases can be the initial presentation of GS. Therefore all patients with this finding should be investigated for GS. Increased IELs may also be associated with autoimmune disorders and NSAIDs.

Coeliac disease

Coeliac disease is a genetically-determined chronic inflammatory intestinal disease induced by an environmental precipitant, gluten. Patients with the disease might have mainly non-gastrointestinal symptoms, and as a result patients present to various medical practitioners. Epidemiological studies have shown that coeliac disease is very common and affects about one in 250 people. The disease is associated with an increased rate of osteoporosis, infertility, autoimmune diseases, and malignant disease, especially lymphomas. The mechanism of the intestinal immune-mediated response is not completely clear, but involves an HLA-DQ2 or HLA-DQ8 restricted T-cell immune reaction in the lamina propria as well as an immune reaction in the intestinal epithelium. An important component of the disease is the intraepithelial lymphocyte that might become clonally expanded in refractory sprue and enteropathy-associated T-cell lymphoma. Study of the mechanism of the immune response in coeliac disease could provide insight into the mechanism of inflammatory and autoimmune responses and lead to innovations in treatment.

The role of antitissue transglutaminase assay for the diagnosis and monitoring of coeliac disease: a French-Italian multicentre study

AIMS

Tissue transglutaminase (tTG) was recently identified as the major autoantigen in coeliac disease. The aim of this multicentre study was to evaluate the impact of a new immunoenzymatic assay for the detection of IgA anti-tGT antibodies.

METHODS

Seventy four Italian and French clinical laboratories participated in this study; anti-tTG IgA with an enzyme linked immunosorbent assay (ELISA) method using guinea pig liver extract as the coating antigen, anti-endomysium IgA autoantibodies (EMA), and total serum IgA were determined in 7948 patients, 1162 of whom had coeliac disease (737 untreated cases and 425 on a gluten free diet). A proportion of the sera were then sent to a reference laboratory for anti-tTG retesting with an ELISA method using recombinant human tTG antigen.

RESULTS

Seven thousand four hundred and fifty eight (93.8%) sera were EMA/antiguinea pig tTG concordant (positive or negative); 490 (6.2%) were non-concordant. The sensitivity of EMA and antiguinea pig tTG in the 737 untreated patients with coeliac disease was 92.1% and 94.8%, respectively, and the specificity was 99.8% and 99.2%, respectively. Retesting of the discordant sera showed that of the 162 sera classified as EMA negative/antiguinea pig tTG positive, only 49 were positive for human recombinant anti-tTG, and that 39 of these were also EMA positive. Furthermore, of the 36 sera classified as EMA positive/antiguinea pig tTG negative, only two were confirmed as EMA positive.

CONCLUSIONS

The antiguinea pig tTG assay is more sensitive but less specific than EMA, whereas the antihuman recombinant tTG assay is far more specific and just as sensitive as antiguinea pig tTG. Testing for EMA presents considerable interpretative problems and is difficult to standardise.

Clinical, radiologic, and induced sputum features of chronic obstructive pulmonary disease in nonsmokers: a descriptive study

Epidemiologic studies show that 5-12% of subjects with chronic obstructive pulmonary disease (COPD) are nonsmokers. Little is known about the pathophysiology of the fixed airflow obstruction in these subjects. We have prospectively identified 25 patients with COPD who had never smoked or had a less than 5 pack years smoking history and present the clinical, radiologic, and induced sputum features. Our population represented 5.7% of total referrals with fixed airflow obstruction over 2 years. Patients had a mean age of 70 years, were predominantly female (86%), and had a mean duration of respiratory symptoms of 7 years. The mean FEV(1) was 58%, and the FEV(1)/FVC was 55%. Features on high-resolution computed tomographic scanning were nonspecific and were considered typical of a wider population with COPD. An induced sputum differential inflammatory cell count suggested the presence of two distinct groups. Nine had significant sputum eosinophilia (mean, 8.1%; normal, less than 1.9%), and the remaining 13 had a normal sputum eosinophil and tended to have a raised sputum neutrophil count (mean, 70.1%; normal, less than 65%). Organ-specific autoimmune disease was present in 7 of the 22 patients (32%) and was particularly prevalent in those without sputum eosinophilia (6 of 13). In conclusion, COPD in nonsmokers predominantly affects females and has at least two pathologic subgroups, one of which may be associated with organ-specific autoimmune disease. Further investigation of this group may disclose novel mechanisms of fixed airflow obstruction.

How common is celiac disease in Eastern Saudi Arabia?

BACKGROUND

In contrast to its prevalence in Europe, celiac disease (CD) is considered rare in non-Caucasian populations. We aimed to estimate the prevalence of CD in clinically suspicious celiac disease patients and in patients with disorders known to be associated with CD, such as autoimmune diseases, using serological assay for IgA-endomysial antibodies (EMA) on inexpensive human tissue substrate.

PATIENTS AND METHODS

IgA-endomysial and IgA-reticulin antibodies (ARA) were evaluated by indirect immunofluorescence (IIF) study using human umbilical cord (HUC) and rat tissues, respectively, in the following groups: group 1, 145 patients with clinical suspicion of CD; group 2, 80 with autoimmune diseases; group 3, 20 patients with inflammatory bowel disease (IBD); and group 4, 100 healthy blood donors.

RESULTS

Of the 145 patients with suspected CD (group 1), 11 were EMA positive with or without ARA, giving a serological prevalence of 7.6%. The histological findings of intestinal biopsy were confirmed in six of them, indicating a CD prevalence of 4%. In group 2, two EMA-positive (2.5%) with or without ARA cases were found. Both were from the 18 patients who had autoimmune thyroid disease, indicating an 11% prevalence of EMA in autoimmune thyroid disease. No positive EMA was detected in the 3rd and 4th groups, indicating 100% specificity.

CONCLUSION

Our findings showed high prevalence of CD in a reference laboratory setting. This highlights the importance of keeping CD in mind and of promptly investigating suspected individuals. There is also a high prevalence of CD among patients with autoimmune thyroid diseases, and further studies are needed to elucidate the significance of this association. Test for endomysial antibodies using human umbilical cord is an inexpensive, easily available and highly specific tool for identifying patients to undergo biopsy and to screen at-risk groups of patients.

A controlled, prospective screening study of celiac disease presenting as iron deficiency anemia

BACKGROUND

anemia is the most frequent presenting feature of celiac disease in adults using endomysial antibody (EmA) screening. Endomysial antibody screening of anemia may allow detection of celiac disease at an earlier stage of investigation and after a shorter duration of symptoms. The characteristics of celiac patients identified by screening require further study.

GOALS

a goal of this study was to evaluate the prevalence of celiac disease in adult patients with iron deficiency anemia compared with a nonanemic control population using immunoglobulin A (IgA) EmA screening. We also studied the positive predictive value (PPV) of the EmA assay and correlated the severity of histologic abnormalities in distal duodenal biopsy samples with EmA and tissue transglutaminase (tTG) antibody titer.

STUDY

four hundred eighty-four patients with microcytic, hypochromic anemia underwent IgA EmA assay. Four hundred ninety-eight nonanemic age- and sex-matched patients from the same source comprised the control group. Patients with positive serology results were invited for endoscopic duodenal biopsies.

RESULTS

one in 44 anemic patients was diagnosed with histologically confirmed celiac disease compared with one in 498 nonanemic patients ( < 0.01). Fifty percent of women were premenopausal, and 25% of patients were older than 65 years. The PPV for EmA assay varied between 73% and 93% for anemic patients and improved at higher antibody titer, with all false-positive results occurring at the lowest titers.

CONCLUSIONS

screening for celiac disease using IgA EmA assay is effective in anemic patients, including premenopausal women and patients older than 65 years, and it can be recommended in clinical practice.

Celiac Disease

Individuals with celiac disease present with a wide array of symptoms and signs. Celiac disease can result in substantial injury to the small intestine, deleterious effects on other organ systems, and an overall doubling of mortality. The role of the gastroenterologist is primarily to make the diagnosis and then to ensure that patients with celiac disease receive up-to-date and accurate instructions on diet. It is our opinion that gastroenterologists should participate in the follow-up of what is in fact a form of inflammatory bowel disease. The failure to identify and treat patients with substantial problems may result in an excess of preventable morbidity and mortality. Intestinal biopsy is the definitive method of making the diagnosis of celiac disease, provided the patient has not excluded gluten from his or her diet, because exclusion of gluten results in negative serologic test results and normal small intestinal biopsy samples. The removal of gluten from the diet can result in a total recovery of gut function and a correction of most other consequences. The response is usually so complete that patients should consider themselves to be basically healthy as long as they stay away from the offending foods. However, the execution and maintenance of the "theoretically simple" exclusion of gluten is difficult. The condition is permanent and mandates adherence to a lifelong gluten-free diet; even small amounts of gluten can result in injury to the intestinal lining. The diet is restrictive and requires the patient to be careful about food choices. Therefore, patient education and motivation are crucial to a successful outcome. The correction of vitamin and mineral deficiencies may be helpful in aiding recovery; vitamin D and calcium supplementation often is recommended. No drug therapy has been proven to suppress the disease.

Diagnostic approach to a patient with suspected celiac disease: a cost analysis

Serological testing is an important tool in the diagnostic work-up of suspected celiac disease. Our aim was to apply a decision analysis model to compare the costs of serological testing versus small bowel biopsy in the diagnostic work-up of celiac disease. A cost-minimization approach was employed. A decision analysis model with three diagnostic arms was designed using Data Version 3.5: anti-gliadin antibody versus endomysial antibody versus small bowel biopsy. Response to gluten-free diet was considered diagnostic of celiac disease; lack of response prompted a small bowel biopsy to definitively exclude celiac disease. Baseline probabilities were varied using sensitivity analysis. Sensitivity analysis revealed that the endomysial antibody strategy was least costly, provided the prevalence of celiac disease was less than 42%; above this anti-gliadin antibody became the most economical option. In conclusion, initial screening with endomysial antibody is the least costly strategy for diagnosing celiac disease in a low risk population. Antigliadin antibody becomes the cheaper strategy for higher risk populations.

Do you still need a biopsy to diagnose celiac disease?

Celiac disease is a common and permanent condition caused by an abnormal immune response to ingested gluten in genetically susceptible individuals. Its proper diagnosis is very important even in patients presenting with mild symptoms because severe and debilitating complications may occur in celiac patients not following a strict gluten-free diet. In the past several years, important progress has been made not only in our understanding of the pathogenesis of this condition but also in the availability of tools to screen it. Antigliadin antibodies, once largely used for this purpose, have been basically replaced by the more costly but far more accurate antiendomysium antibodies. More recently, the enzyme-linked immunosorbent assay (ELISA), which measures the antibodies directed against the autoantigen responsible for the disease (tissue transglutaminase), has also been developed and tested as a screening tool. Currently, however, the poor positive predictive value of this test does not allow practitioners to diagnose celiac disease without the duodenal biopsy showing the typical morphologic changes.