What are the sensitivity and specificity of serologic tests for celiac disease? Do sensitivity and specificity vary in different populations?

Celiac disease in children and adolescents: special considerations

Although there are many commonalities between adult and pediatric celiac disease (CD), special considerations must be taken into account when working with children and adolescents. In this patient population, there are unique aspects of the epidemiology, pathogenesis, presentation, diagnosis, and management of CD. In terms of management, early and timely recognition of CD can maximize childhood and adolescent development and prevent complications. This requires insight into the unique presentations of CD in the pediatric population. Furthermore, health care providers must use proper screening methods and continue surveillance of at-risk individuals throughout childhood. Potential interventions for primary prevention of CD in children, although not completely understood, may offer some benefit. The goals of this article are to discuss in detail these special considerations when dealing with pediatric CD.

Open conformation tissue transglutaminase testing for celiac dietary assessment

OBJECTIVES

Anti tissue-transglutaminase antibody is the mainstay of celiac disease serologic testing. Whilst it has high sensitivity in patients on an unrestricted diet, sensitivity is poor for evaluation of gluten free diet adherence.

AIM

To assess the utility of a novel assay measuring Immunoglobulin-A antibodies to catalytically active open conformation tissue-transglutaminase in assessment of ongoing gluten exposure in celiac disease patients on an alleged gluten free diet.

METHODS

Through prospective assessment, 147 patients with celiac disease were divided into good and poor adherence. Open and closed (conventional) tissue-transglutaminase titres were measured using standard enzyme linked immunosorbent assay. 50 patients with inflammatory bowel disease served as disease controls.

RESULTS

Overall 128 patients had been on gluten free diet for more than six months and 19 were found to be poorly adherent on dietary review. Within this group 13 (68.4%) and 10 (52.6%) patients respectively were positive for the open conformation and conventional assay (p=0.51). Two and one control patients tested positive for closed and open assays respectively.

CONCLUSIONS

Compared to native assays open conformation tissue-transglutaminase may have higher sensitivity in the poor gluten free diet adherence group and higher specificity in the control population. Larger population studies are warranted to assess whether the open conformation tissue-transglutaminase assay may be superior to the conventional assay.

Noncoeliac enteropathy: the differential diagnosis of villous atrophy in contemporary clinical practice

BACKGROUND

Duodenal villous atrophy (DVA) is a key diagnostic finding in coeliac disease (CD). However, the differential diagnosis for this finding is broad.

AIM

To identify conditions causing noncoeliac enteropathy (NCE) with villous atrophy and methods to differentiate between CD and NCE in clinical practice.

METHODS

Through record review we identified patients with DVA due to conditions other than CD. Patient demographics, clinical features and relevant investigations were compared with CD patients. Rates of CD misdiagnosis, and response to treatments were recorded.

RESULTS

Thirty cases of NCE were identified with ten different aetiologies. Unspecified immune-mediated enteropathy was the most common aetiology; affecting 10 patients. Gastrointestinal symptoms were more common in NCE than those in CD patients (P < 0.01). Twenty of the 24 NCE patients tested were HLA-DQ2/DQ8 negative. Twenty-six NCE patients were negative for IgA tissue transglutaminase (tTG) (P = 0.0001). Intraepithelial lymphocytosis was absent in 10 (33.3%) patients. Twenty-one NCE patients initially misdiagnosed with CD and one with gluten intolerance were prescribed a gluten free diet (GFD). Fifteen of 22 had repeat biopsy and none showed histological improvement.

CONCLUSIONS

Although coeliac disease is the most common cause of DVA, noncoeliac enteropathy is not rare and may easily be mistaken for coeliac disease. Noncoeliac enteropathy is suggested by a normal initial tTG (87%), lack of intraepithelial lymphocytosis on biopsy, and lack of histological response to a gluten free diet. Subjective response to gluten free diet has poor predictive value for coeliac disease. Noncoeliac enteropathy can often be confirmed by negative HLA-DQ2/DQ8 testing and targeted investigations can ascertain a definitive aetiology in most cases.

Gluten sensitivity: problems of an emerging condition separate from celiac disease

Gluten sensitivity appears to be emerging as a separate condition from celiac disease, yet no clear definition or diagnosis exists. As a result, patients with gluten sensitivity experience delayed diagnosis and continuing symptoms if they consume gluten. This emerging medical problem may involve human genetics, plant genetic modifications, gluten as a food additive, environmental toxins, hormonal influences, intestinal infections and autoimmune diseases. The treatment is similar to that for celiac disease - a gluten-free diet. The use of a gluten-free diet or an elimination diet is encouraged in assisting people to determine whether or not they are gluten sensitive. It is time to not only recognize, but to treat and further research gluten sensitivity, as unconfirmed environmental factors continue to spread this problem further into the general population.

Low risk of gastrointestinal cancer among patients with celiac disease, inflammation, or latent celiac disease

BACKGROUND & AIMS

Celiac disease has been associated with gastrointestinal (GI) cancers in small studies; risks have not been estimated from large populations or based on histopathology analyses.

METHODS

We examined the risk of GI cancers by using data from cohorts of patients with celiac disease (villous atrophy, Marsh score of 3; n = 28,882) or inflammation (Marsh score of 1-2; n = 12,860); biopsy samples were evaluated at 28 pathology centers. A third cohort included 3705 individuals with latent celiac disease (normal mucosa, but positive serology results). Data were compared with those from an age- and sex-matched population.

RESULTS

Of patients with celiac disease, 372 developed incident GI cancers; 347 patients with inflammation and 38 with latent celiac disease developed GI cancers. In the first year after diagnosis and initial biopsy, celiac disease was associated with 5.95-fold increase in risk of incident GI cancer (95% confidence interval [CI], 4.64-7.64); the hazard ratio [HR] for inflammation was 9.13 (95% CI, 7.19-11.6) and for latent celiac disease was 8.10 (95% CI, 4.69-14.0). After the first year, patients were at no significant increase in risk for GI cancers; the HR for celiac disease was 1.07 (95% CI, 0.93-1.23), for inflammation it was 1.16 (95% CI, 0.98-1.37), and for latent celiac disease it was 0.96 (95% CI, 0.56-1.66). The absolute risk for any GI cancer in patients with celiac disease was 101/100,000 person-years, with an excess risk of 2/100,000 person-years.

CONCLUSIONS

Although celiac disease, inflammation, and latent disease all increase risk for GI cancers in the first year after diagnosis, there is no increase in risk thereafter.

Coeliac Disease in the 21st Century: No Longer "Kids' Stuff"

Background

We aimed to determine if Coeliac disease (CD) can be still be considered a predominantly paediatric disorder, in spite of the increased incidence of adult-onset CD reported in recent years.

Methods

An observational, descriptive, and retrospective study was developed at two Spanish hospitals. Data was collected and analyzed from all paediatric and adult patients newly diagnosed with CD throughout the year 2010. CD diagnoses were based on a concordant clinical history, serology, HLA-DQ compatibility, the presence of mucosal lesions in duodenal biopsies with gluten dependence of symptoms, and histological lesions.

Results

A total of 79 patients were diagnosed with CD throughout 2010, of which 68 (86.1%) were adults. Classic symptoms (diarrhoea and iron-deficiency anaemia) were more frequent in children (90.9%), being present in only 54.4% of adults (p = 0.02). Adult patients showed, mainly, abdominal pain, dyspepsia, and GERD-related symptoms. Villous atrophy (Marsh III) was present in 63.7% of children, but only in 19.1% of adults (p = 0.004). Positive tTGA was present in 81.8% of the children and only in 19.1% of the adults (p = 0.004). Haemoglobin levels were significantly lower in children (p = 0.025), but no differences were observed in iron and ferritin blood levels.

Conclusions

Our study shows that adult-onset CD was the predominant presentation in two hospitals in Spain in the year 2010. Therefore, CD can no longer be considered a predominantly paediatric disorder. Marsh I and negative tTGA titters are characteristic in most of adults. New diagnostic algorithms are needed to improve correct diagnosis of CD in adults.

Assessment of a combination screening assay for celiac disease

PURPOSE

A serological screening assay for celiac disease (CD), designed to simultaneously detect IgA and IgG anti-tissue transglutaminase (a-tTG) and IgA and IgG deamidated gliadin peptide antibodies (a-DGP), was recently developed. In this study, we establish the performance of this assay.

METHODS

We enrolled 41 CD patients and 18 CD patients on gluten-free diets. The diagnosis of CD was based on histological and serological criteria, including concomitant positive serology tests (a-tTG, IgA anti-endomysial antibodies). As control population, we enrolled 169 subjects: 145 disease controls and 24 blood donors. In all cases, serum samples were tested for: IgA a-tTG, IgG a-tTG, IgA a-DGP, IgG a-DGP, IgA anti-endomysial antibodies (EMA), IgA and IgG for a-tTG and a-DGP in a single assay.

RESULTS

The new test, QUANTA Lite (™) h-tTG/DGP Screen, detects all IgA and IgG antibodies against atTG and a-DGP present in a sample. In our study, the test showed 100% sensitivity and 91.12% specificity.

CONCLUSIONS

This study showed additional value of the new h-tTG/DGP Screen assay, which proved superior to more conventional assays and can be considered the best initial test for CD. Further studies are necessary to determine whether combination of h-tTG/DGP Screen with IgA a-tTG or IgA a-DGP can be used to obviate the need for duodenal biopsy in high- and low-risk populations.

Celiac disease: implications for patient management

Celiac disease is an autoimmune disorder that is known specifically for causing inflammation of the mucosa in the small intestine. Through multiple diagnostic and screening tools such as small intestinal biopsy sample, serological testing, and human leukocyte antigen testing, healthcare providers can diagnose this disease that contains components related to genetic predisposition and intake of gluten proteins found in wheat, barley, and rye. There are some who believe that having an autoimmune disease may predispose one to acquiring another disease. With patients experiencing mostly diarrhea, abdominal pain, and weight loss, the implementation of a gluten-free diet is the treatment that healthcare providers recommend. Through monitoring gluten intake and providing nutritional supplementation, those diagnosed with celiac disease can lead a relatively normal life without complications. With celiac disease affecting all age ranges in the population, and with a documented higher frequency, there is a growing awareness in society that can be easily seen in grocery stores, restaurants, and food manufacturers.

Immunoglobulin G antibodies against deamidated-gliadin-peptides outperform anti-endomysium and tissue transglutaminase antibodies in children <2 years age

To investigate the usefulness of deamidated-gliadin-peptides-antibodies in the diagnosis of celiac disease, serology was tested in 212 children suspected with celiac disease who had undergone a small-intestinal-biopsy. For deamidated-gliadin-peptides-antibodies, two kits were tested. Positive and negative predictive values for IgA deamidated-gliadin-peptides-antibodies using the Bindazyme-kit were 89% and 74%, while the Quanta-Lite-kit had values of 89% and 85%, respectively. For the IgG subtype using the Bindazyme-kit, these values were 85% and 89%, while they were 85% and 91% for the Quanta-Lite-kit. The positive predictive values for endomysium and tissue-transglutaminase antibodies were disappointing (77% and 87%), although the negative predictive values were better (97% and 96%). When the analysis was restricted to the 41 children aged <2 years, no misclassifications occurred with IgG deamidated-gliadin-peptides-antibodies giving 100% accuracy in both kits. The positive predictive value reached 100% for tissue-transglutaminase antibodies and both kits for IgA deamidated-gliadin-peptides-antibodies, while the negative predictive value was 94% in these assays. Positive and negative predictive values for endomysium antibodies were 96% and 93%, respectively. In conclusion, although deamidated-gliadin-peptides-antibodies do not outperform anti-endomysium antibodies in the total study population, the IgG subtype seems to be the best test in children aged <2 years, reaching 100% accuracy.

Increased suicide risk in coeliac disease--a Swedish nationwide cohort study

BACKGROUND AND AIM

Individuals with coeliac disease have increased risk of depression and death from external causes, but conclusive studies on death from suicide are missing. We examined the risk of suicide in coeliac disease and amongst individuals where the small intestinal biopsy showed no villous atrophy.

METHODS

We collected biopsy data from all 28 clinical pathology departments in Sweden for individuals diagnosed during 1969-2007 with coeliac disease (Marsh 3: villous atrophy; n=29,083 unique individuals), inflammation without villous atrophy (Marsh 1-2; n=13,263) or positive coeliac disease serology but normal mucosa (Marsh 0, n=3719). Through Cox regression we calculated Hazard ratios for suicide as recorded in the Swedish Cause of Death Register.

RESULTS

The risk for suicide was higher in patients with coeliac disease compared to general population controls (HR=1.55; 95%CI=1.15-2.10; based on 54 completed suicides). Whilst suicide was also more common amongst individuals with inflammation (HR=1.96; 95%CI=1.39-2.77), no such increase was seen amongst individuals with a normal mucosa but positive coeliac disease serology (HR=1.06; 95%CI=0.37-3.02).

CONCLUSIONS

We found a moderately increased risk of suicide amongst patients with coeliac disease. This merits increased attention amongst physicians treating these patients.

[Anti-transglutaminase, antigladin and ultra purified anti-gladin antibodies in patients with a diagnosis of rheumatoid arthritis]

Celiac disease (CD) is an enteric disease caused by dietary gluten in individuals with genetic predisposition. One of the clinical manifestations of CD is the peripheral arthritis that may simulate RA.

OBJECTIVE

To determine the frequency of anti-gliadin (aGL), anti-tissue transglutaminase (aTGT) and ultra purified anti-gliadin (AGLU) antibodies in patients with RA.

METHODS

Cross-sectional study. We included consecutive patients diagnosed as RA (ACR). Demographic and clinical data was registered by direct interview and serum levels of aGL, aTGT y aGLU were determined using ELISA.

RESULTS

Eighty-five RA patients were included; 87% were women. Mean age was 44±12 years, mean disease duration 12 ±9 years. aGL IgG antibodies were positive in 16 patients, IgA aGL antibodies in 29 patients, aGLU in 14 patients and only one patient had aTGT.

CONCLUSIONS

It is possible that CD may be the correct diagnosis in a patient with polyarthritis, even if the patient meets the ACR criteria for RA. In other words, CD should be considered among the differential diagnoses in a patient with poly-arthritis.

Use of deamidated gliadin peptide antibodies to monitor diet compliance in childhood celiac disease

OBJECTIVE

The aim of this study was to evaluate performance of serum antibodies against deamidated gliadin peptides (a-DGPs) in detecting compliance with gluten-free diet (GFD) in children with celiac disease (CD).

PATIENTS AND METHODS

Serum samples were collected the same day of endoscopy in 95 children with CD and 106 controls. We preliminarily calculated the cutoff of a-DGP immunoglobulin A (IgA) and a-DGP IgA+G in our population by receiver operating characteristic (ROC) curves. Of 95 children with CD, 28 were studied during the first year after GFD introduction, with interview and serum collection every 3 months. In addition, serum samples were collected in 106 children with CD on GFD for more than 1 year (range 1-14). In both groups of children with CD on GFD, we compared a-DGP IgA and IgA+G performance in monitoring compliance with GFD with anti-tissue transglutaminase antibodies (anti-tTG) IgA and anti-gliadin antibody (AGA) IgA.

RESULTS

The cutoff resulted in 13.1 arbitrary units (AU) for a-DGP IgA (sensitivity 87.4, 95% confidence interval [CI] 79%-92%, specificity 97.2, 95% CI 92%-99%) and 16.5 for a-DGP IgA+G (sensitivity 94.7, 95% CI 88%-98%, specificity 89.6, 95% CI 84%-95%). In the first year of GFD, at 6 to 8 months prevalence of positive a-DGPs was significantly higher in partially versus strictly compliant children, and at 9 to 12 months only prevalence of positive a-DGP IgA+G remained significantly higher. Moreover, at 9 to 12 months sensitivity to detect transgressions to GFD was 44% for a-DGP IgA and 100% for a-DGP IgA+G (P = 0.03). In the 106 children on GFD for more than 1 year, sensitivity to detect transgressions to GFD was 60% for a-DGP IgA and 76% for a-DGP IgA+G. Anti-tTG IgA and AGA IgA sensitivity was much lower (24% and 4%, respectively). The 4 tests showed comparable high specificity.

CONCLUSIONS

Both a-DGPs showed higher sensitivity than anti-tTG IgA and AGA IgA in monitoring compliance with GFD, but a-DGP IgA+G seemed to perform better. a-DGPs did not outperform anti-tTG IgA for CD screening.

HLA-DQ genotyping combined with serological markers for the diagnosis of celiac disease: is intestinal biopsy still mandatory?

OBJECTIVES

The aim of this study was to evaluate the value of HLA-DQ2/DQ8 allelic genotyping combined with serologic testing for the diagnosis of celiac disease (CD).

PATIENTS AND METHODS

One hundred seventy children, who underwent jejunal biopsy for digestive symptoms or malnutrition, were tested for HLA-DQ2/DQ8 and serologic markers (tTG and/or anti-endomysial antibodies). Children were classified in 2 groups, according to jejunal histology: group 1, when partial or total villous atrophy was associated with an increased intraepithelial lymphocytosis suggesting CD, and group 2, when these histological criteria were absent.

RESULTS

Eight children were excluded from the study because their intestinal histology was not informative; 82 children were classified in group 1 and 80 in group 2. Eighty-one of 82 children in group 1 were positive for HLA and serologic testing. The other child had negative HLA and serologic testing but marked villous atrophy, and further investigation showed an allergic disease. Among the 80 children in group 2, 53 were negative for both HLA and serologic testing, 22 were positive for HLA but negative for serologic testing, 2 were negative for HLA and positive for serologic testing, and 3 patients were positive for both HLA and serologic testing. The last 3 children were shown to have an autoimmune background and had probably a latent form of CD. The association of HLA-DQ2/DQ8 and serologic markers had a sensitivity of 98.8%, a specificity of 96.2%, a positive likelihood ratio of 26.3, and a negative likelihood ratio of 0.013.

CONCLUSIONS

The association of positive HLA-DQ2/DQ8 and serologic testing has a high predictive value for CD. We suggest that symptomatic children with high titers of immunoglobulin (Ig)A tTG could be diagnosed as patients with CD without performing jejunal biopsy. In other children, HLA-DQ2/DQ8 could be useful to exclude the diagnosis of CD if negative. In cases of low IgA tTG titers or in patients with IgA deficiency, intestinal biopsy remains mandatory.

What is the use of biopsy and antibodies in coeliac disease diagnosis?

The advent of highly sensitive and specific serological markers has led to some protagonists proposing that coeliac disease can be diagnosed without the need for a biopsy. However, this is an area of controversy. Lack of consensus about diagnostic degrees of histological change, paucity of symptoms, antibody-negative disease and immunodeficiency can make diagnosis difficult even with a biopsy. Conversely, an argument can be put forward for a 'no biopsy' approach based on the large number of patients with typical symptoms and positive serology who experience a diagnostic delay. In addition, endoscopy is not without discomfort. This article discusses the use of antibodies and duodenal biopsy within this context. Finally, we propose a pragmatic diagnostic algorithm for clinicians to use when investigating patients for coeliac disease.

The anti-deamidated gliadin peptide antibodies unmask celiac disease in small children with chronic diarrhoea

OBJECTIVES

To assess the usefulness of a new class of antibodies, the anti-deamidated gliadin peptides, in the diagnostic approach to children less than 2 years with suspected celiac disease.

PATIENTS AND METHODS

We investigated 40 children (median age: 16.8 months; age range: 4-24 months), with symptoms and signs of chronic enteropathy and high serum levels of conventional anti-gliadin antibodies, but normal values of anti-transglutaminase and anti-endomysial antibodies; all underwent measurement of anti-deamidated gliadin peptides serum levels, upper gastrointestinal endoscopy with biopsies and HLA typing; 40 subjects served as controls.

RESULTS

In 29 patients (group A) serum levels of anti-deamidated gliadin peptides were normal and duodenal histology showed a spectrum of abnormalities ranging from mucosal inflammatory infiltrates to villous damage (in almost all cases compatible with Marsh 1-to-2 lesions). All improved on a cow's and soy milk free diet containing gluten. In 11 patients (group B) there were high serum levels of anti-deamidated gliadin peptides and histology showed features suggestive of celiac disease (Marsh 2-to-3 lesions) in all; furthermore, human leucocyte antigen typing was consistent with a celiac disease genetic pattern in all. Group B patients significantly improved on a gluten free diet containing cow's and soy milk proteins. None of the control group was anti-deamidated gliadin peptides positive.

CONCLUSIONS

In children younger than 2 years with signs of chronic enteropathy and normal values of classical serum markers of celiac disease, the latter can be predicted by high serum levels of anti-deamidated gliadin peptides.

Estimation of (IgA) anti-gliadin, anti-endomysium and tissue transglutaminase in the serum of patients with psoriasis

Studies have indicated an association between psoriasis and coeliac disease (CD), an immune-mediated gluten-dependent enteropathy; however, the precise relationship between psoriasis and CD remains controversial. We aimed to assess the prevalence of the CD-associated IgA antibodies antigliadin antibody (AGA), tissue transglutaminase (tTG) and antiendomysium antibody (EMA) in patients with psoriasis. In total, 41 patients with psoriasis and 41 healthy controls were enrolled in this study. Blood samples were taken from all participants, and screened for AGA, tTG and EMA. We found a significantly higher level of AGA in patients with psoriasis than in controls, but levels of tTG and EMA were not significant. There was also a significantly higher prevalence of AGA, tTG and EMA in the patient group (34.1%, 34.1% and 14.6%, respectively) than in the control group (2.4%, 22% and 4.9%, respectively). We conclude that the significantly high prevalence of AGA antibodies in patients with psoriasis supports the possibility of a link between psoriasis and gluten-sensitive enteropathies, especially CD.

Update on serologic testing in celiac disease

Contemporary serologic testing has revolutionized the field of celiac disease (CD). Highly accurate serologic assays have shown the prevalence of CD to be nearly 1:100 in many populations. These mostly ELISA (enzyme-linked immunosorbent assay)-based tests allow noninvasive screening and detection. However, the growing number of available serologic tests necessitates reevaluation of their predictive power as a single test or in combination. We review the available tests for CD, including antibodies against gliadin, endomysium, tissue transglutaminase, and deamidated gliadin, and the evidence for preferential use of specific tests in different settings. Despite several novel developments, standardized ELISA-based assays for IgA autoantibodies against tissue transglutaminase remain the test of choice for most populations. We discuss the need to develop tests for CD activity in order to assess the efficacy of upcoming nondietary therapies.

Increased risk of hospital admission for influenza in patients with celiac disease: a nationwide cohort study in Sweden

OBJECTIVES

Although earlier studies suggest an increased risk of infectious disease in celiac disease (CD), data on the risk of influenza in patients with CD are limited. We examined the risk of hospital admission for influenza in CD patients, but for comparative reasons also in individuals with small-intestinal inflammation or normal mucosa but positive CD serology.

METHODS

In 2006-2008, we collected duodenal/jejunal biopsy data on CD (Marsh 3: villous atrophy, VA; n=29,008 unique individuals) and inflammation (Marsh 1-2; n=13,200) from all 28 pathology departments in Sweden. A third regional cohort consisted of 3,709 individuals with positive CD serology but normal mucosa (Marsh 0). The biopsies were performed between 1969 and 2008. Through linkage with the Swedish Hospital Discharge Register, we estimated the risk of hospital admission for influenza compared with that of 224,114 age- and sex-matched controls from the general population.

RESULTS

Individuals with CD were at increased risk of hospital admission for influenza (hazard ratio (HR)=2.1; 95% confidence interval (CI)=1.6-2.7; n=81). The absolute risk of influenza was 30/100,000 person-years (excess risk: 16/100,000 person-years). Furthermore, children with CD were at increased risk of influenza (HR=2.5; 95% CI=1.3-4.8). Whereas individuals with inflammation without VA were also at increased risk of influenza (HR=1.9; 95% CI=1.4-2.5), individuals with normal mucosa but positive CD serology were not (HR=1.2; 95% CI=0.5-3.0).

CONCLUSIONS

This study found an increased risk of hospital admission for influenza in patients with CD.

Coeliac disease in autoimmune liver disease: a cross-sectional study and a systematic review

BACKGROUND

Several studies have reported an association between coeliac disease and autoimmune liver disease, but there is little information on the prevalence of coeliac disease in certain autoimmune liver diseases, particularly from non-European, non-American countries.

AIMS

To investigate prevalence of coeliac disease in autoimmune liver disease in Iran and to summarize previous literature.

METHODS

We investigated prevalence of coeliac disease among 100 autoimmune liver disease patients and compared it with the prevalence in healthy individuals. We also performed an extensive search of the English literature in PubMed Database.

RESULTS

We found substantially elevated prevalence of coeliac disease in patients with overlap syndrome (10-15%) compared to the general population (0.1-1%). To a lesser extent, the prevalence was high in patients with autoimmune hepatitis (2-4%). In our systematic review, prevalence of coeliac disease in autoimmune hepatitis in the majority of studies was 4% or more; several studies also reported such prevalence in primary biliary cirrhosis.

CONCLUSIONS

Since coeliac disease is common among patients with autoimmune liver disease, screening autoimmune liver disease patients for coeliac disease is indicated. Although the magnitude of benefit from a gluten-free diet in reversing autoimmune liver disease in patients with coeliac disease is controversial, it may reduce the risk of further complications of coeliac disease.

Current methods to diagnose the unresponsive and complicated forms of coeliac disease

Coeliac disease is a common disorder. Due to the protean manifestations of the disease and the often mild but indolent course, the diagnosis is often missed. The method to diagnose this in principle reversible disease after the introduction of a gluten-free diet has attracted the attention of several scientific disciplines to find the simplest and most patient-friendly test. This has resulted in a noticeable impact on the clinical practice next to a general increased awareness of its existence, its pathogenesis, its course and recent evidence of increased mortality. Amendments made in the diagnostic criteria of coeliac disease over the last half century have simplified the diagnosis. However, the aspect most relevant to the specialist in internal medicine is related to its grave consequences when the disease fails to respond to a gluten-free diet. These refractory cases may culminate in severe complications with sombre endings and malignancy. Fortunately, current technology can offer the specialist in internal medicine more facilities to diagnose the cause of the complicated cases in order to attempt to intervene in the course of disease and hopefully save these patients. We review the available tools that now exist and their indications that can be practiced in a modern clinical setting for the diagnosis of the complicated forms of this disease.

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.

Celiac disease serology in patients with different pretest probabilities: Is biopsy avoidable?

AIM: To establish the diagnostic performance of several serological tests, individually and in combination, for diagnosing celiac disease (CD) in patients with different pretest probabilities, and to explore potential serological algorithms to reduce the necessity for biopsy.

METHODS: We prospectively performed duodenal biopsy and serology in 679 adults who had either high risk (n = 161) or low risk (n = 518) for CD. Blood samples were tested using six assays (enzyme-linked immunosorbent assay) that detected antibodies to tissue transglutaminase (tTG) and deamidated gliadin peptide (DGP).

RESULTS: CD prevalence was 39.1% in the high-risk population and 3.3% in the low-risk group. In high-risk patients, all individual assays had a high diagnostic efficacy [area under receiving operator characteristic curves (AU ROC): 0.968 to 0.999]. In contrast, assays had a lower diagnostic efficacy (AU ROC: 0.835 to 0.972) in the low-risk group. Using assay combinations, it would be possible to reach or rule out diagnosis of CD without biopsy in 92% of cases in both pretest populations. We observed that the new DGP/tTG Screen assay resulted in a surplus compared to more conventional assays in any clinical situation.

CONCLUSION: The DGP/tTG Screen assay could be considered as the best initial test for CD. Combinations of two tests, including a DGP/tTG Screen, might be able to diagnose CD accurately in different clinical scenarios making biopsy avoidable in a high proportion of subjects.

Novel screening assay performance in pediatric celiac disease and adult dermatitis herpetiformis

OBJECTIVES

: Several serologic assays are commercially available to aid in the diagnosis of gluten-sensitive enteropathy (GSE). Our objective in this study was to assess the performance of a novel combined antigen-screening assay for GSE.

PATIENTS AND METHODS

: Deidentified sera from 111 pediatric patients suspected of having celiac disease (CD), 130 adults diagnosed with dermatitis herpetiformis (DH), and 77 pediatric and 49 adult normal controls were included in the study. Sera from 10 patients submitted to our laboratory for GSE testing with IgA deficiency and IgG antibodies against 1 or more of the traditional serologic markers associated with GSE were also included. All sera were screened for antibodies (IgA and IgG) against tissue transglutaminase (tTG) and deamidated gliadin peptides (DGP) by enzyme immunoassay (EIA) in a single test well. In addition, all sera were assessed for each individual marker and isotype using separate EIAs.

RESULTS

: The IgA/IgG anti-tTG/DGP EIA screen was 92.6% sensitive and 94.3% specific in pediatric CD and detected 1 patient (Marsh 3c) who was IgA anti-tTG negative; this patient was not IgA deficient (<7.0 mg/dL). All 10 IgA-deficient sera gave positive results by the tTG/DGP EIA screen. Sensitivity and specificity of the tTG/DGP EIA screen in retrospective and prospective DH were 65% and 100% versus 62% and 100%, respectively.

CONCLUSIONS

: The new IgA/IgG anti-tTG/DGP EIA screen was slightly more sensitive than IgA anti-tTG alone in pediatric CD. This novel screening assay may allow the current recommendation of measuring total serum IgA in suspected GSE patients to be eliminated.

Celiac disease and pediatric type 1 diabetes: diagnostic and treatment dilemmas

Despite the advent of sensitive and specific serologic testing, routine screening for celiac disease (CD) in diabetic populations may not be universal practice, and many clinicians struggle to find the optimal approach to managing CD in pediatric Type 1 diabetes (T1D) patients. While some clinicians advocate screening for CD in all patients with T1D, others are unsure whether this is warranted. The diagnosis of patients who present with symptomatic CD, including malabsorption and obvious pathology upon biopsy, remains straightforward, with improvements noted on a gluten-free diet. Many patients identified by screening, however, tend to be asymptomatic. Evidence is inconclusive as to whether the benefits of screening and potentially treating asymptomatic individuals outweigh the harms of managing a population already burdened with a serious illness. This review focuses on current knowledge of CD in children and youth with T1D, highlighting important elements of the disease's pathophysiology, epidemiology, clinical presentation, and diagnostic challenges.

Celiac disease and the gluten-free diet

Celiac disease (CD) is now recognized as one of the most common genetic diseases of humankind. Furthermore, and contrary to previous opinion that categorized CD as a primarily pediatric disorder, CD can occur at any age and can present with a wide range of clinical manifestations. Missed and delayed CD diagnoses are common for a number of reasons, one of which is a lack of CD awareness among primary healthcare clinicians. The purpose of this article is to increase clinicians’ knowledge and awareness of CD.

Diagnostic immunology in celiac disease

Serum autoantibodies to transglutaminase and endomysium are found in the majority of patients with celiac disease, an autoimmune multisystem disorder affecting approximately 1% of Western and Middle-Eastern populations. Detection of these antibodies plays a crucial role in the diagnosis of celiac disease. The aim of this review is to summarize recent publications in this field, with particular focus on the applications and limitations of celiac autoantibody testing in routine clinical practice.

Celiac disease seropositivity in Saharawi children: a follow-up and family study

BACKGROUND

Celiac disease (CD) is a common disease in the Saharawi population of Arab-Berber origin. Saharawi patients with CD and their families were invited to participate in a follow-up study aimed at checking the CD serology status in patients being treated with the gluten-free diet (GFD) and investigating the prevalence of CD in first-degree relatives.

PATIENTS AND METHODS

We investigated 975 subjects (62.8% females and 37.2% males, age range 0.7 to 75.4 years, median age 13.4 years) belonging to 212 families, by determining the serum immunoglobulin A anti-transglutaminase and anti-endomysial antibody levels. Thirty-two first-degree relatives were already receiving GFD when tested.

RESULTS

Overall, 42.2% of the 244 treated subjects with CD showed a borderline/positive anti-transglutaminase determination, and 36.6% were also anti-endomysial positive. The serologic family screening detected 33 previously undiagnosed CD cases. The 65 affected first-degree relatives were sibling (42), mother (12), son/daughter (7), and father (4). The overall prevalence of CD among first-degree relatives was 65 of 763 (8.5%, 95% confidence interval 6.5-10.5). Based on our previous estimate of CD prevalence in the pediatric Saharawi population (5.6%), the sibling relative risk was 1.5.

CONCLUSIONS

The risk of CD in the Saharawis is only modestly increased in first-degree relatives compared with the general population, probably because of the higher frequency of CD predisposing genes in the general population. Saharawi patients with CD receiving GFD showed poor adherence to the treatment, which could contribute to residual CD-related morbidity and mortality.

New Serology Assays Can Detect Gluten Sensitivity among Enteropathy Patients Seronegative for Anti–Tissue Transglutaminase

Background: Some patients with celiac disease (CD) may be seronegative with the commonly used test for IgA anti–tissue transglutaminase (anti-tTG) antibodies. Our aim was to explore whether newer assays incorporating synthetic deamidated gliadin-related peptides (DGPs) or other TG isoenzymes as antigen are useful for detecting gluten sensitivity in IgA anti-tTG–seronegative patients.

Methods: We assayed serum samples obtained at diagnosis from (a) anti-tTG–seronegative patients with a CD-like enteropathy (n = 12), (b) skin biopsy–proven dermatitis herpetiformis (DH) patients (n = 26), and (c) IgA anti-tTG–positive CD patients (n = 26). All patients had typical total IgA concentrations. All patients underwent intestinal biopsy and serum testing for (a) detection of IgA and IgG isotypes of both anti-DGP and anti-tTG in a single assay (tTG/DGP Screen; INOVA Diagnostics), (b) simultaneous detection of both IgA and IgG anti-DGP antibody isotypes (DGP Dual; INOVA Diagnostics), and (c) detection of antibodies to transglutaminase 3 (TG3) or transglutaminase 6 (TG6).

Results: All anti-tTG–seropositive patients also tested positive in anti-DGP assays. Overall, tTG/DGP Screen detected 6 (31.6%) of the 19 anti-tTG seronegatives, and anti-DGP Dual produced positive results in 5 (26.3%) of these cases. Whereas both assays detected 2 anti-tTG–negative DH patients with partial villous atrophy, they were positive in only 2 of the 5 cases with no histologically discernible mucosal damage. Testing for antibodies to TG3 and TG6 identified 7 (36.8%) of the 19 anti-tTG–negative patients, 5 of which were also positive for anti-DGP.

Conclusions: Detection of anti-DGP with tTG/DGP Screen or anti-DGP Dual, or detection of antibodies to other TG isoenzymes, enhances the sensitivity for detecting gluten sensitivity among non–IgA- deficient, anti-tTG–seronegative patients with CD-like enteropathy.

[Celiac disease]

Celiac disease is an enteropathy due to gluten intake in genetically predisposed individuals (HLA DQ2/DQ8). Celiac disease occurs in adults and children at rates approaching 1% of population in Europe and USA. Clinical features observed in celiac disease are extremely various and anaemia, oral aphthous stomatis, amenorrhea or articular symptoms may be the only presenting manifestations. Diagnosis relies on the evidence of histological villous atrophy in proximal small bowel and the presence of specific serum antibodies. Treatment relies on eviction of gluten (wheat, barley, rye) from diet. Gluten free diet allows prevention of malignant complications such as small bowel adenocarcinoma and lymphoma, and osteopenia. The main cause of resistance to gluten free diet is its poor observance. If not the case, serious complications of celiac disease, such as clonal refractory celiac sprue and intestinal T-cell lymphoma should be suspected. Current therapeutic challenges concern alternative to gluten free diet and new efficient treatments of lymphomatous complications.

Suboptimal performance of IgG anti-tissue transglutaminase in the diagnosis of celiac disease in a tropical country

Serological tests using human IgA-anti-tTG have been reported to have high sensitivity and specificity in diagnosis of celiac disease. There is a paucity of data on the use of human IgG-anti-tTG in diagnosis of celiac disease. Ninety-two patients with clinical suspicion of celiac disease who underwent duodenal mucosal biopsy and celiac serology using human IgG-anti-tTG were included in this retrospective study. Diagnostic accuracy of human recombinant IgG-anti-tTG serological test for celiac disease was evaluated. Indications for celiac serological testing were diarrhea (92.3%), hypoalbuminemia (39.1%), and anemia (35.9%). Eighteen patients were diagnosed with having celiac disease and 14 (77.8%) of them were IgG-anti-tTG positive. Of the remaining 74 patients, eight (10.8%) were false-positive for IgG-anti-tTG. Sensitivity, specificity, PPV, NPV, and diagnostic accuracy of IgG-anti-tTG in celiac disease were 77.8, 89.1, 63.6, 94.2, and 87%, respectively. Human IgG-anti-tTG alone does not perform well as a diagnostic tool for celiac disease. The utility of anti-endomysial antibodies in a similar clinical setting needs to be evaluated.

Diagnostic performance of IgG anti-deamidated gliadin peptide antibody assays is comparable to IgA anti-tTG in celiac disease

BACKGROUND

Detection of IgG antibodies against deamidated gliadin peptides (DGP) is more sensitive and more specific for celiac disease than detection of IgG antibodies against native gliadin. Our aim was to evaluate the technical performance and diagnostic accuracy of four commercial IgG anti-DGP assays.

METHODS

Commercial IgG anti-DGP assays from Euroimmun, Inova, Phadia and The Binding Site were evaluated and their diagnostic accuracy (sensitivity and specificity) compared to other serologic assays for celiac disease (3IgA and 2IgG anti-tTG assays, 1IgA and 1IgG anti-gliadin assay, 1IgA anti-DGP assay). The study population consisted of 86 consecutive CD patients and 741 disease controls.

RESULTS

The technical performance (linearity, interference and imprecision) of the IgG anti-DGP assays was acceptable. The sensitivity of the IgG anti-DGP assays varied between 76.7% and 86.0% at the cut-off recommended by the manufacturer and between 74.4% and 86.0% at the cut-off that corresponded to a specificity of 98%. The specificity varied between 97.3% and 99.3%. The diagnostic accuracy of the IgG anti-DGP assays was comparable to the diagnostic accuracy of the IgA anti-tTG assays. The sensitivity of the IgG anti-DGP assays was significantly better than sensitivity of the IgG anti-tTG assays (p<0.05) and the specificity was significantly better than the IgA and IgG anti-gliadin assays (p<0.05).

CONCLUSIONS

The overall performance of the four IgG anti-DGP assays was acceptable and the diagnostic accuracy comparable to the three IgA anti-tTG assays.

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.

Screening detects a high proportion of celiac disease in young HLA-genotyped children

BACKGROUND AND AIMS

Celiac disease is associated with tissue transglutaminase autoantibodies (tTGAb) and the human leukocyte antigen (HLA)-risk alleles DQB1*02 and DQB1*0302. The aim was to estimate the proportion of undiagnosed celiac disease in children with HLA risk at 3 years of age.

PATIENTS AND METHODS

From a population-based HLA-DQ screening study of newborns born between June 2001 and August 2004 in the southern part of Sweden, 6206 children with HLA-risk alleles were identified and asked to participate at a mean 3.3 +/- 0.4 years of age. As controls, 7654 children with HLA-nonrisk alleles were asked to participate. In all, 1620 (26.1%) children with HLA risk and 1815 (23.7%) controls were screened for tTGAb using radioligand-binding assays. Celiac disease was established by intestinal biopsy in children with a confirmed positive tTGAb test.

RESULTS

Twenty-three children reported already having clinically diagnosed celiac disease and did not participate further. In children with HLA-risk genotypes, 73 of 1620 (4.5%, 95% CI 3.5%-5.5%) were tTGAb-positive compared with none of 1815 from the controls (P < 0.0001). Seventy-one children underwent biopsy (1 refused biopsy and 1 biopsy failed), of whom 56 of 1618 (3.5%, 95% CI 2.6%-4.4%) had damaged intestinal mucosa classified as celiac disease. The ratio between clinically and screening detected celiac disease in this study was 1:2.4 (23:56).

CONCLUSIONS

The proportion of clinically undetected celiac disease may be particularly high among 3-year-old children with HLA-DQB1*02 and DQB1*0302 in Sweden, where these 2 HLA-risk alleles frequently occur.

Anti-transglutaminase antibodies in non-coeliac children suffering from infectious diseases

Anti-transglutaminase antibodies are the diagnostic markers of coeliac disease. A role is suggested for infectious agents in the production of anti-transglutaminase antibodies. The aim was to measure positive anti-transglutaminase antibody levels in children with infectious diseases and to compare immunological and biological characteristics of the anti-transglutaminase antibodies derived from these children with that from coeliac patients. Two hundred and twenty-two children suffering from infectious diseases were enrolled prospectively along with seven biopsy-proven coeliacs. Serum samples were tested for anti-transglutaminase antibodies and anti-endomysium antibodies; positive samples were tested for coeliac-related human leucocyte antigen (HLA)-DQ2/8 and anti-viral antibodies. Purified anti-transglutaminase antibodies from the two study groups were tested for urea-dependent avidity, and their ability to induce cytoskeletal rearrangement and to modulate cell-cycle in Caco-2 cells, using phalloidin staining and bromodeoxyuridine incorporation assays, respectively. Nine of 222 children (4%) tested positive to anti-transglutaminase, one of whom also tested positive for anti-endomysium antibodies. This patient was positive for HLA-DQ2 and was diagnosed as coeliac following intestinal biopsy. Of the eight remaining children, two were positive for HLA-DQ8. Levels of anti-transglutaminase returned to normal in all subjects, despite a gluten-containing diet. Purified anti-transglutaminase of the two study groups induced actin rearrangements and cell-cycle progression. During an infectious disease, anti-transglutaminase antibodies can be produced temporarily and independently of gluten. The infection-triggered anti-transglutaminase antibodies have the same biological properties as that of the coeliacs, with the same in-vivo potential for damage.

Performance of serology assays for diagnosing celiac disease in a clinical setting

Diagnosis of celiac disease frequently depends upon serology assays. We set out to prospectively assess the diagnostic value of five serology tests: an enzyme-linked immunosorbent assay (ELISA) for tissue transglutaminase (tTG)-immunoglobulin A (IgA) and tTG-IgG, a chemiluminescence assay for tTG-IgA, an ELISA for deamidated gliadin peptide (DGP) IgG and IgA screening, and detection of endomysial antibodies (Abs) by indirect immunofluorescence. One hundred sixteen children at high risk for developing celiac disease were evaluated clinically and underwent small bowel biopsies and blood serology tests. We examined differences between younger and older children in terms of clinical presentation, test performance, and the ability of high Ab levels to correctly predict diagnosis of celiac disease. Celiac disease was diagnosed for 85 (73%) children. No significant clinical differences were observed between the biopsy-positive and biopsy-negative groups. Children < or = 3 years of age revealed higher concentrations of tTG-IgA and DGP Abs than children >3 years old (P = 0.017 and 0.007, respectively). High Ab concentrations were predictive of villous atrophies, with sensitivities ranging from 92.8% to 97.9%, depending on the assay and the cutoff points applied. Sensitivities, specificities, positive predictive values, and negative predictive values varied among assays and improved after correction for best cutoff points. Assay specificities obtained in the clinical setting were lower than expected. The new tTG-IgA chemiluminescence assay demonstrated high throughput but low specificity (74.2%). The tTG-IgA ELISA exhibited the highest test efficiency, and the tTG-IgA chemiluminescence assay was suitable for large-scale screening, with reduced specificity. High concentrations of celiac disease-specific Abs bring into question the need for performance of biopsies on children at high risk.

Celiac disease in the elderly

It has become apparent recently that celiac disease, once believed to be primarily a childhood disease, can affect people of any age. Epidemiologic studies have suggested that a substantial portion of patients are diagnosed after the age of 50. Indeed, in one study, the median age at the diagnosis was just under the age of 50 with one-third of new patients diagnosed being older than 65 years. The purpose of this review is to address the prevalence, clinical features, diagnosis, and consequences of celiac disease in the elderly. The authors also review management strategies for celiac disease and adjust these with emphasis on the particular nutritional and nonnutritional consequences or associations of celiac disease as they pertain to the elderly.

[Seroprevalence of celiac disease at a general pediatric outpatient clinic]

BACKGROUND

Celiac disease is a common problem affecting children and adults, for which early diagnosis and treatment prevent complications and deaths. Seroprevalence studies in our environment are still scarce.

AIMS

To determine the seroprevalence of celiac disease by using human tissue antiendomysial and anti-transglutaminase antibodies, among children and adolescents who were attended at a general pediatric outpatient clinic.

METHODS

This was a seroprevalence study of descriptive cross-sectional design. First, assays for guinea pig tissue anti-transglutaminase antibodies were performed. Subsequently, in the positive cases, assays for human tissue antiendomysial and anti-transglutaminase antibodies were performed.

RESULTS

The seroprevalence of celiac disease by means of anti-guinea pig tissue anti-transglutaminase antibodies was 5% (42/831; 95% CI: 3.76%-6.90%). Considering three positive tests, the seroprevalence was 1.9% (16/831; 95% CI: 1.83%-1.97%). The concordance of human anti-transglutaminase with antiendomysial was 71%.

CONCLUSIONS

The seroprevalence of celiac disease was high. Serological screening for celiac disease among children and adolescents who present signs and/or symptoms compatible with celiac disease should be performed routinely, as well as in groups already known to be at risk, given the high seroprevalence of celiac disease observed in our environment.

Prevalence of celiac disease among patients with Behcet's disease in Iran

BACKGROUND

Behcet's disease and Celiac disease, both common in Iran, share many immunopathogenic and clinical features. Based on the possible association between these two diseases, this study is designed to determine the frequency of non-diagnosed celiac disease in patients with Behcet's disease.

METHODS

The sera of 288 consecutive patients with Behcet's disease were screened with anti-endomysial antibody and anti-tissue transglutaminase antibody for celiac disease. Those with a positive test underwent upper gastrointestinal endoscopy and duodenal biopsies to confirm the diagnosis of celiac disease. The patients with celiac disease were put on a gluten free diet to evaluate its efficacy on the improvement of their lesions.

RESULTS

Fourteen patients had positive anti-tissue transglutaminase antibody test (two with positive anti-endomysial antibody as well). Duodenal biopsies showed findings compatible with Marsh 3 in one and Marsh 1 in three other patients. All the diagnosed patients with celiac disease responded to the gluten free diet.

CONCLUSION

Our findings didn't support any association between celiac disease and Behcet's disease in Iranian patients compared to the general population of Iran.

Symptoms and signs in individuals with serology positive for celiac disease but normal mucosa

Background

Antibody serology is an important tool in the investigation of celiac disease (CD), but does not always correlate with mucosal appearance in the small intestine. Patients with positive CD serology but normal mucosa (Marsh 0) are at increased risk of future CD. In this study we describe a model for identifying and characterizing individuals with normal mucosa but positive CD serology. Such individuals are sometimes referred to as having latent CD.

Methods

The records of ten Swedish pathology departments were used to identify individuals with biopsies indicating normal duodenal/jejunal mucosa. Using the national personal identification number, these data were linked with CD serology data (antigliadin, antiendomysial and tissue transglutaminase antibodies); and we thereby identified 3,736 individuals with normal mucosa but positive CD serology. Two independent reviewers then manually reviewed their biopsy reports to estimate comorbidity. We also randomly selected 112 individuals for validation through patient chart review.

Results

The majority of the 3,736 individuals were females (62%). Children (0–15 years) made up 21.4%. The median number of biopsy specimen was 3. Our review of biopsy reports found that other gastrointestinal comorbidity was rare (inflammatory bowel disease: 0.4%; helicobacter pylori infection: 0.2%). Some 22% individuals selected for patient chart review had a relative with CD. The most common symptoms among these individuals were diarrhea (46%) and abdominal pain (45%), while 26% had anemia. Although 27% of the individuals selected for validation had been informed about gluten-free diet, only 13% were adhering to a gluten-free diet at the end of follow-up.

Conclusion

Individuals with positive CD serology but normal mucosa often have CD-like symptoms and a family history of CD.

Antibodies against deamidated gliadin as new and accurate biomarkers of childhood coeliac disease

OBJECTIVES

Assays of tissue transglutaminase antibodies (anti-tTG) represent the cornerstone of serological coeliac disease (CD) diagnostics. Assays of antibodies against native gliadin (anti-nGli) lost importance due to low validity. We investigated the performance of new assays for antibodies against deamidated gliadin (anti-dGli) in childhood CD.

METHODS

We retrospectively compared children (142 with active CD and 160 without CD, diagnosis confirmed or excluded by intestinal biopsy) concerning (immunoglobulin [Ig] G and IgA) anti-nGli, anti-tTG, and 2 different anti-dGli assays.

RESULTS

IgG-anti-dGli1, IgG-anti-dGli2, and IgA-anti-tTG performed similarly. Area under the receiver-operating characteristic curve (AUC) was 98.6%, 98.9%, and 97.9%; accuracy was 94.7%, 95.7%, and 96.7%. Anti-dGli1 and anti-dGli2 (IgG and IgA) and IgA-anti-tTG performed significantly better than IgA-anti-nGli and IgG-anti-nGli. Both IgG-anti-dGli showed higher AUC and accuracy than IgA-anti-dGli and IgG-anti-tTG. Combined evaluation of IgA-anti-tTG with one of the IgG-anti-dGli tests reduced the rate of falsely classified patients. At enhanced cutoff (specificity >99%), sensitivity was above 67% for both IgG-anti-dGli and IgA-anti-tTG. If IgA-anti-tTG assay was combined with one of the IgG-anti-dGli tests, then the fraction of patients identified with more than 99% specificity as coeliacs increased significantly above 84.5%. Combined evaluation of the 2 IgG-anti-dGli tests did not improve the performance.

CONCLUSIONS

The new IgA and IgG-anti-dGli tests outperform conventional anti-nGli assays. The validity of IgG-anti-dGli cannot be distinguished from IgA-anti-tTG. It should be studied prospectively whether antibody assays could replace biopsy in diagnosis of CD in a substantial segment of children.

Enteroscopy in the diagnosis and management of celiac disease

Esophagogastroduodenoscopy (EGD) with 3 to 6 biopsies in the descending duodenum is the gold standard for the diagnosis of celiac disease. At the time of the first diagnosis of celiac disease, an extensive evaluation of the small bowel is not recommended. However, video capsule endoscopy, because of its good sensitivity and specificity in recognizing the Endoscopic features of celiac disease, can be considered a valid alternative to EGD in patients unable or unwilling to undergo EGD with biopsies. Capsule endoscopy is also a possible option in selected cases with strong suspicion of celiac disease but negative first-line tests. In evaluating patients with refractory or complicated celiac disease, in whom a complete evaluation of the small bowel is mandatory (at least in refractory celiac disease type II patients) because of the possible presence of complications beyond the reach of conventional endoscopes, both capsule endoscopy and balloon-assisted enteroscopy have been found to be helpful. In these patients, capsule endoscopy offers several advantages: it is well tolerated, it allows inspection of the entire small bowel, and it is able to recognize subtle mucosal changes. However, in this setting, capsule endoscopy should ideally be coupled with imaging techniques that provide important information about the thickness of the wall of the intestine and about extraluminal abnormalities. Although deep enteroscopy (such as balloon enteroscopy) is expensive, time-consuming, and potentially risky in these frail patients, they may have a key role, because they make it possible to take tissue samples from deep in the small intestine.