Low specificity of anti-tissue transglutaminase antibodies in patients with primary biliary cirrhosis

Primary Biliary Cholangitis: Epidemiology, Diagnosis, and Presentation

Using ursodeoxycholic acid as a standard treatment and for its ability to test for antimitochondrial antibody to accelerate diagnosis, survival of primary biliary cholangitis patients has approached that of the general population, leading to a change in nomenclature from primary biliary cirrhosis to primary biliary cholangitis to more accurately describe the disease.

Effect of helicobacter pylori infection eradication on serum level of anti-tissue transglutaminase in children with celiac disease

BACKGROUND

Evidence shows the increase of anti-tissue transglutaminase (tTG) levels in various conditions, including infectious agents, independently of celiac disease (CD). The aim of this study was to investigate the effect of helicobacter pylori (H.pylori) infection eradication on serum level of tTG in children with CD.

METHODS

This study was conducted on children aged 2 to 18 who referred to reference hospitals for diagnosis of CD. After upper endoscopy and biopsy to confirm CD and H.pylori infection, the children were divided into three groups (including group one: 16 CD patients with positive H. pylori; group two: 16 non-CD patients with positive H. pylori; and group three: 56 CD patients with negative H. pylori), respectively. The tTG level in study groups were compared after the eradication of H.pylori.

RESULTS

The mean age of the subjects in the group one, two, and three was 9.7 ± 3.33, 11.8 ± 3.14, and 7.6 ± 3.32 years, respectively. Our results showed that in group one, mean tTG increased after eradication of H.pylori infection, however, these changes were not significant (182.43 vs. 157.18, P = 0.121). In the second group, although unlike the first group, mean tTG decreased after eradication of the infection, but still these changes were not significant (9.56 vs. 22.18, P = 0.449). Furthermore, at the baseline level, the mean tTG in the group three was closer to the mean tTG in the first group.

CONCLUSION

Our findings showed that the eradication of H.pylori infection does not have a significant effect on tTG levels in children with and without CD.

Autoantibodies in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic immune-mediated liver disease characterized by a lymphocytic cholangitis, with subsequent cholestasis, progressive liver fibrosis, and ultimately complications arising from end-stage liver disease. Testing for autoantibodies is important in the diagnosis of PBC, as well as stratifying prognosis. This review focuses on the role of autoantibodies in the diagnosis of PBC, as well as the relationship between autoantibodies with pathophysiology and prognostication, along with a discussion regarding novel and other related disease autoantibodies.

Evaluation of the Utility of Amino Acid Citrulline as a Surrogate Metabolomic Biomarker for the Diagnosis of Celiac Disease

INTRODUCTION

Citrulline is regarded as a biomarker for celiac disease (CD). Its utility for assessment and evaluation of additive predictive value for latent, potential CD and first degree relatives (FDRs) needs exploration.

METHOD

Consecutive 558 index cases diagnosed as per European Society for Pediatric Gastroenterology and Nutrition (ESPGHAN) 2012 guidelines and their 1565 FDRs were evaluated over five and half year period. Serology negative FDRs at initial visit and follow ups were served as controls. HLA typing for DQ2 and DQ8 genotypes, along with plasma and dried blood spot (DBS) filter paper citrulline were evaluated.

RESULTS

Median plasma citrulline values were 20.1 and 37.33 µMol/l in cases and controls (P < .001). Cut off values for Marsh grade 3a, 3b, and 3c were 35.0, 32.8, 25.26 µMol/l in CD patients and 36.51, 30.10, 25.26 µMol/l in biopsy proven FDR. Increasing trends of plasma citrulline levels with decreasing tTG-IgA levels were observed on follow up. Low plasma citrulline levels were observed with HLA DQ 2.5 genotype (P < .05). Agreement between DBS and plasma citrulline was 94.8%.

CONCLUSION

Citrulline is a good surrogate biomarker for identification of histopathological grade of damage, extent of mucosal recovery and has negative correlation with tTG-IgA. It identifies the silent and latent phase of CD. DBS citrulline provides adequate information and can be used for monitoring CD patients at remote locations.

Low Titer Tissue Transglutaminase Antibodies: A Link to Helicobacter pylori Infection?

INTRODUCTION

Low serum titer of anti-tissue transglutaminase (tTG) has been described in various conditions without any evidence of celiac disease (CD). Infectious agents have been suggested to trigger autoimmunity and promote the production of anti-tTG. The aim of this study was to investigate if there is a link between a positive celiac serology and concomitant Helicobacter pylori infection in children.

METHODS

The data of 178 pediatric patients who underwent upper gastrointestinal endoscopy due to positive celiac serology were compiled. The patients whose histopathologic findings were not consistent with CD were followed on gluten-containing diet. The changes in the serum level of anti-tTG IgA on the follow-up were compared between H. pylori-infected and noninfected patients after the eradication of H. pylori.

RESULTS

Of 155 patients who met the inclusion criteria, 119 (group 1) were diagnosed as CD, and duodenal histopathology of the remaining 36 children (group 2) was not compatible with CD. In group 2, 11 out of 36 (30.5%) patients were infected with H. pylori. After the eradication of H. pylori, anti-tTG IgA level either decreased or dropped below cutoff value in 9/11 (81%) patients while it was 20% in those who were not infected with H. pylori in the 6th month of the follow-up (p = 0.001).

CONCLUSION

Our results suggest that H. pylori infection may be the cause of false or transient positive celiac serology. Thus, a positive celiac serology should be carefully interpreted in the presence of H. pylori infection before confirming the diagnosis of this life-long disease.

Discordance Between Serology and Histology for Celiac Disease in a Cohort with Coexisting Liver Disorders

Background

The liver and celiac disease (CeD) share a complex relationship. While in some patients, isolated hypertransaminasemia is the only manifestation of CeD, liver diseases (LD) may also be associated with the presence of isolated tissue transglutaminase antibodies IgA (tTG IgA) without histologic evidence of CeD.

Aims

To examine the yield of tTG IgA testing (a) in the workup for chronic liver disease (CLD) or cytolysis and (b) to identify biopsy-confirmed CeD (BxCeD) among patients with concomitant LD.

Methods

Retrospective study including two cohorts. Cohort 1 represented 444 consecutive individuals without known CeD for which liver specialists requested tTG IgA. Incidence of positive tTG and BxCeD was evaluated. Cohort 2 included 212 consecutive individuals with positive tTG IgA and subsequent duodenal biopsies. The frequency and clinical characteristics of individuals without BxCeD were examined, with and without concurrent LD.

Results

The rate of first time positive tTG IgA among the tests requested by a liver specialist (cohort 1) was 2.0% (n = 9). However, 33.0% (n = 3) of these patients did not have BxCeD. Cohort 2 included 33 individuals with coexisting LD, of which 42.4% did not have BxCeD, compared with 16.2% of the patients without LD (P < 0.001). The majority of the patients without BxCeD (65.1%) showed an increase < 3 times upper limit of normal of tTG IgA.

Conclusions

Although there is clinical value in testing for CeD in the context of LD, there could be a high rate of positive CeD serology unaccompanied by histologic signs in patients with coexisting LD.

Transient elevation of anti-transglutaminase and anti-endomysium antibodies in Giardia infection

Markers of celiac disease (CeD) may be elevated in various conditions of intestinal inflammation or autoimmune disease. Recent reports argue that intestinal infection may induce development of CeD in susceptible individuals. Serum anti-tissue transglutaminase (tTG) and anti-endomysium antibodies (EMA) have been proposed in previous reports to be helpful in differentiating between giardiasis and CeD. In this report, we describe eight cases with elevated CeD serological markers and pathological duodenal histology during, or shortly after, Giardia infection. We present follow-up clinical and serological findings to determine which of these that were diagnosed with CeD. Serum levels of tTGand EMA did not discriminate well between patients where CeD was excluded, and those who were later diagnosed with CeD. The value of these serological CeD markers is discussed in relation to CeD diagnosis in cases with chronic or recent giardiasis.

Clinicopathological and immunological characteristics and outcome of concomitant coeliac disease and non-alcoholic fatty liver disease in adults: a large prospective longitudinal study

Objective

Concomitant non-alcoholic fatty liver disease (NAFLD) and coeliac disease (CD) have not been adequately studied. This study investigated the frequency of CD among NAFLD patients and the clinicopathological and immunological patterns and outcome of concomitant NAFLD and CD.

Design

This prospective longitudinal study screened patients with NAFLD for CD (tissue transglutaminase antibodies (TTGA); anti-TTGA and antiendomysial antibodies (EMA)). Patients with concomitant NAFLD and CD and patients with either NAFLD or CD were enrolled and followed. Duodenal biopsy, transient elastography, tumour necrosis factor (TNF)-alpha, transforming growth factor-beta, interleukins (ILs) 1, 6, 10, 15 and 17, folic acid and vitamins B12 and D were performed at baseline and 1 year after gluten-free diet (GFD).

Results

CD was confirmed in 7.2% of patients with NAFLD. Refractory anaemia and nutritional deficiencies were frequent in patients with concomitant NAFLD and CD who had advanced intestinal and hepatic lesions, higher levels of TNF-α, IL-15 and IL-17 compared with patients with CD and NAFLD. Patients concomittant CD and NAFLD showed clinical response to GFD, but intestinal histological improvement was suboptimal. Combining EMA-IgA or anti-TTGA with either IL-15 or IL-17 enhances the prognostic performance of both tests in predicting histological response to GFD.

Conclusion

Concomitant NAFLD and CD is not uncommon. Recurrent abdominal symptoms, refractory anaemia, nutritional deficiencies in patients with NAFLD warrant screening for CD. The study has important clinical implications since failure in diagnosing CD in patients with NAFLD patients results in marked intestinal and hepatic damage and suboptimal response to GFD that can be alleviated by early diagnosis and initiation of GFD.

Strategies to improve the efficiency of celiac disease diagnosis in the laboratory

The demand for testing to detect celiac disease (CD) autoantibodies has increased, together with the cost per case diagnosed, resulting in the adoption of measures to restrict laboratory testing. We designed this study to determine whether opportunistic screening to detect CD-associated autoantibodies had advantages compared to efforts to restrict testing, and to identify the most cost-effective diagnostic strategy. We compared a group of 1678 patients in which autoantibody testing was restricted to cases in which the test referral was considered appropriate (G1) to a group of 2140 patients in which test referrals were not reviewed or restricted (G2). Two algorithms A (quantifying IgA and Tissue transglutaminase IgA [TG-IgA] in all patients), and B (quantifying only TG-IgA in all patients) were used in each group, and the cost-effectiveness of each strategy was calculated. TG-IgA autoantibodies were positive in 62 G1 patients and 69 G2 patients. Among those positive for tissue transglutaminase IgA and endomysial IgA autoantibodies, the proportion of patients with de novo autoantibodies was lower (p=0.028) in G1 (11/62) than in G2 (24/69). Algorithm B required fewer determinations than algorithm A in both G1 (2310 vs 3493; p<0.001) and G2 (2196 vs 4435; p<0.001). With algorithm B the proportion of patients in whom IgA was tested was lower (p<0.001) in G2 (29/2140) than in G1 (617/1678). The lowest cost per case diagnosed (4.63 euros/patient) was found with algorithm B in G2. We conclude that opportunistic screening has advantages compared to efforts in the laboratory to restrict CD diagnostic testing. The most cost-effective strategy was based on the use of an appropriate algorithm.

Clinical and biological correlations in celiac disease in children: the prospective single experience of a romanian tertiary center: A case-control study (Strobe-Compliant study)

Celiac disease-a chronic inflammatory disease of the intestine-is triggered by gluten or associated protein consumption.The aim of our study was to assess the sensitivity, specificity of the combined anti-transglutaminase 2 (TG2)/deamidated gliadin peptide antibodies (DGP), and antiendomisium antibodies (EMA), to determine the distribution of HLA-DQ2/DQ8 for the 140 tested patients, and also to evaluate the clinical and laboratory characteristics of patients admitted with the suspicion of celiac disease (CD). Children included in the study were divided into: group 1, patients with confirmed CD; group 2, patients with "potential' CD; group 3, control group, patients without CD. We assessed the standard laboratory data, the level of TG2/DGP and EMA antibodies, as well as the distribution of HLA molecules in the selected patients. Histopathological examination was considered the criterion standard for diagnosis in most cases.The sensitivity of TG2/DGP was 85% and the specificity 92%. EMA showed a sensitivity of 82% and a specificity of 98%. The vast majority of patients diagnosed with CD were either HLA-DQ2.5 (encoded by DQA1*05 & DQB1*02) positive (87.5%) or HLA-DQ8 (encoded by DQB1*03:02) positive (12.5%). One patient showed a positivity only for HLA-DQ2.2 (encoded by DQA1*02 & B1*02).Our study showed that the genetic risk for CD was present in more than one-third of the cases without a confirmed diagnosis of CD. Therefore, the awareness of genetic susceptibility for CD is essential because of the fact that these individuals can develop the disease at any point of their lives. The sensitivity of TG2/DGP and EMA were very similar, whereas EMA presented a higher specificity as that of TG2/DGP.

To screen or not to screen? Celiac antibodies in liver diseases

Celiac disease (CD) is a systemic immune-mediated disorder triggered by dietary gluten in genetically predisposed individuals. The typical symptoms are anemia, diarrhea, fatigue, weight loss, and abdominal pain. CD has been reported in patients with primary sclerosing cholangitis, primary biliary cholangitis, autoimmune hepatitis, aminotransferase elevations, nonalcoholic fatty liver disease, hepatitis B, hepatitis C, portal hypertension and liver cirrhosis. We evaluate recommendations for active screening for CD in patients with liver diseases, and the effect of a gluten-free diet in these different settings. Active screening for CD is recommended in patients with liver diseases, particularly in those with autoimmune disorders, steatosis in the absence of metabolic syndrome, noncirrhotic intrahepatic portal hypertension, cryptogenic cirrhosis, and in the context of liver transplantation. In hepatitis C, diagnosis of CD can be important as a relative contraindication to interferon use. Gluten-free diet ameliorates the symptoms associated with CD; however, the associated liver disease may improve, remain the same, or progress.

Evaluation of the ESPGHAN Celiac Guidelines in a North American Pediatric Population

OBJECTIVES

We retrospectively examined the performance of the tissue transglutaminase (TTG), endomysial antibody (EMA) tests, and the ESPGHAN (European Society of Paediatric Gastroenterology, Hepatology and Nutrition) nonbiopsy criteria in a pediatric population.

METHODS

Consecutive celiac serologies and corresponding intestinal biopsy results were obtained on children <18 years old over 3.5 years. Patients were classified into three categories: positive TTG, negative TTG, and IgA deficiency.

RESULTS

Of the 17,505 patients with celiac serology performed, 775 had a positive TTG, 574 with a negative TTG were biopsied, and 25 were IgA deficient. Of the patients with a TTG ≥10 × upper limit of normal (ULN), positive EMA, and symptoms, 98.2% had biopsies consistent with celiac disease (CD). Four human leukocyte antigen (HLA) DQ2/DQ8-positive patients who met the ESPGHAN nonbiopsy criteria did not have CD. In the group with a TTG 3-10 × ULN, 75.7% EMA-positive patients and only 40% EMA-negative patients had CD (P<0.001). Of those with a TTG 1-3 × ULN, 52.2% EMA-positive patients vs. only 13.3% EMA-negative patients had CD (P<0.01). Of the patients with bulbar and duodenal biopsies, 9.8% had CD confined only in the bulb, especially those with a low titer TTG (P<0.01). CD prevalence in our cohort was 34.6%. Sensitivity, specificity, and positive predictive value of the TTG were 98.7%, 86.4%, and 79.4%, respectively.

CONCLUSIONS

The TTG is a very sensitive screen for CD, but positive predictive value improves with a positive EMA titer. To apply the new ESPGHAN guidelines, clinicians must understand the performance of their celiac serology tests.

Celiac disease in adult patients: specific autoantibodies in the diagnosis, monitoring, and screening

The increasing prevalence of celiac disease (CD), especially in adults, its atypical clinical presentation, and the strict, lifelong adherence to gluten-free diet (GFD) as the only option for healthy state create an imperative need for noninvasive methods that can effectively diagnose CD and monitor GFD. Aim. Evaluation of anti-endomysium (EmA) and anti-tissue transglutaminase IgA (tTG-A) antibodies in CD diagnosis, GFD monitoring, and first degree relatives screening in CD adult patients. Methods. 70 newly diagnosed Greek adult patients, 70 controls, and 47 first degree relatives were tested for the presence of EmA and tTG-A. The CD patients were monitored during a 3-year period. Results. EmA predictive ability for CD diagnosis was slightly better compared to tTG-A (P = 0.043). EmA could assess compliance with GFD already from the beginning of the diet, while both EmA and tTG-A had an equal ability to discriminate between strictly and partially compliant patients after the first semester and so on. Screening of first degree relatives resulted in the identification of 2 undiagnosed CD cases. Conclusions. Both EmA and tTG-A are suitable markers in the CD diagnosis, in the screening of CD among first degree relatives, having also an equal performance in the long term monitoring.

Anti-actin IgA antibodies identify celiac disease patients with a Marsh 3 intestinal damage among subjects with moderate anti-TG2 levels

A new diagnostic tool (algorithm-1) for coeliac disease (CD) permitting the diagnosis without performing the duodenal biopsy has been recently proposed by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN). It combines symptoms associated with CD, high anti-transglutaminase type 2 antibody (anti-TG2) levels, anti-endomysium-IgA antibodies (EMA), and at-risk HLA. Our aims were (i) to evaluate retrospectively in 227 individuals (149 CD patients and 78 controls) the algorithm-1, (ii) to reduce the number of duodenal biopsies among CD patients for whom algorithm-1 is not applicable through the addition of antiactin IgA antibodies (AAA-IgA), and (iii) to evaluate prospectively algorithm-1 and AAA-IgA in 50 patients with suspected CD. Algorithm-1 identified 70 out of 149 CD patients with Marsh 3 lesions. Adding AAA-IgA to the remaining patients with anti-TG2 levels comprised between 4 and 10 times upper limit of normal (ULN) allowed the detection of further 20 patients with a Marsh 3 damage. In our prospective study, algorithm-1 identified 23 out of 50 patients, whilst further 7 were recognized adding AAA-IgA. We confirm that algorithm-1 may avoid the duodenal biopsy in many CD patients and underscores the usefulness of AAA-IgA in reducing the number of duodenal biopsies in patients with moderate anti-TG2 levels.

Gut-liver axis: an immune link between celiac disease and primary biliary cirrhosis

The association between celiac disease and primary biliary cirrhosis is well established. The breakdown of gut-liver axis equilibrium plays a central role in the development of immune disorders involving the small bowel and liver. In celiac disease, immunologically active molecules generated from the cross-linking between tissue transglutaminase and food/bacterial antigens reach the liver through the portal circulation owing to the increased intestinal permeability. A molecular mimicry between bacterial antigens and the pyruvate dehydrogenase E2 component, recognized by antimitochondrial autoantibodies, may have a role in primary biliary cirrhosis pathogenesis. An aberrant intestinal T lymphocyte homing to the liver may contribute to trigger immune hepatic damage. Both celiac disease and primary biliary cirrhosis share several features, including a higher prevalence in females, autoimmune comorbidities and specific autoantibodies. Reciprocal screening for both diseases is recommended, as an early diagnosis with the appropriate treatment can improve the outcome of these patients.

High prevalence of celiac disease among Saudi children with type 1 diabetes: a prospective cross-sectional study

Background

There is lack of data on prevalence of celiac disease (CD) in children with type 1 diabetes (T1D) in Arabs in the Middle East. The present investigation aims to study the prevalence rate and clinical characteristics of CD among Saudi children with T1D using a combination of the most sensitive and specific screening serologic tests (anti- tissue transglutaminase antibodies IgA [anti-TTG] and ednomyseal antibodies [EMA]) and to determine the lower cut-off value of anti- anti-TTG level that best predicts CD in children with T1D.

Methods

Children with T1D following in diabetic clinic have been prospectively screened for presence of CD, over a two-year period (2008–2010), by doing anti-TTG, EMA, and total IgA. Children with positive anti-TTG titres (>50 U/ml) and/or EMA and children with persistently low positive anti-TTG titres (two readings 20–50 U/ml; within 6 months intervals) had upper endoscopy and 6 duodenal biopsies.

Results

One hundred and six children with T1D have been screened for CD: age ranged between 8 months to 15.5 years (62 females). Nineteen children had positive anti-TTG and/or EMA, however only 12 children had biopsy proven CD (11.3%). Five of 12 had gastrointestinal symptoms (42%). Children with T1D and CD had significantly lower serum iron than children with T1D alone (8.5 μgm/L Vs 12.5 μgm/L; P = 0.014). The sensitivity and specificity of anti-TTG were 91.6% and 93.6%, with a positive and negative predictive value of 64.7% and 98.8%, respectively. Receiver operated characteristics analysis for the best cut-off value of anti-TTG level for diagnosis of CD was 63 units (sensitivity 100% and specificity 98.8%).

Conclusion

CD is highly prevalent among Saudi children with T1D. Anti-TTG titres more than 3 times the upper limit of normal has very high sensitivity and specificity for diagnosis of CD in T1D children.

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.

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hepatobiliary disorders in celiac disease: an update

This communication reviews recent literature and summarizes hepatobiliary abnormalities that may complicate the clinical course of celiac disease. A wide spectrum of hepatobiliary diseases has been described, including asymptomatic elevations of liver enzyme levels, nonspecific hepatitis, nonalcoholic fatty liver disease, and autoimmune and cholestatic liver disease. Moreover, in the majority of patients, liver enzyme levels will normalize on a gluten-free diet. In addition, celiac disease may be associated with rare hepatic complications, such as hepatic T-cell lymphoma. Because many celiac patients do not have overt gastrointestinal symptoms, a high index of suspicion is required. Simple methods of detecting celiac disease such as serum antibody tests help in the early identification of the disease, thus preventing serious complications of the disorder. The IgG DGP antibody test and IgA tTG antibody test used in combination are an excellent screening test for suspected cases of celiac disease.

Clinical utility of serologic testing for celiac disease in ontario: an evidence-based analysis

OBJECTIVE OF ANALYSIS: The objective of this evidence-based evaluation is to assess the accuracy of serologic tests in the diagnosis of celiac disease in subjects with symptoms consistent with this disease. Furthermore the impact of these tests in the diagnostic pathway of the disease and decision making was also evaluated. CELIAC DISEASE: Celiac disease is an autoimmune disease that develops in genetically predisposed individuals. The immunological response is triggered by ingestion of gluten, a protein that is present in wheat, rye, and barley. The treatment consists of strict lifelong adherence to a gluten-free diet (GFD). Patients with celiac disease may present with a myriad of symptoms such as diarrhea, abdominal pain, weight loss, iron deficiency anemia, dermatitis herpetiformis, among others.

SEROLOGIC TESTING IN THE DIAGNOSIS CELIAC DISEASE

There are a number of serologic tests used in the diagnosis of celiac disease. Anti-gliadin antibody (AGA)Anti-endomysial antibody (EMA)Anti-tissue transglutaminase antibody (tTG)Anti-deamidated gliadin peptides antibodies (DGP)Serologic tests are automated with the exception of the EMA test, which is more time-consuming and operator-dependent than the other tests. For each serologic test, both immunoglobulin A (IgA) or G (IgG) can be measured, however, IgA measurement is the standard antibody measured in celiac disease.

DIAGNOSIS OF CELIAC DISEASE

According to celiac disease guidelines, the diagnosis of celiac disease is established by small bowel biopsy. Serologic tests are used to initially detect and to support the diagnosis of celiac disease. A small bowel biopsy is indicated in individuals with a positive serologic test. In some cases an endoscopy and small bowel biopsy may be required even with a negative serologic test. The diagnosis of celiac disease must be performed on a gluten-containing diet since the small intestine abnormalities and the serologic antibody levels may resolve or improve on a GFD. Since IgA measurement is the standard for the serologic celiac disease tests, false negatives may occur in IgA-deficient individuals.

INCIDENCE AND PREVALENCE OF CELIAC DISEASE

The incidence and prevalence of celiac disease in the general population and in subjects with symptoms consistent with or at higher risk of celiac disease based on systematic reviews published in 2004 and 2009 are summarized below.

INCIDENCE OF CELIAC DISEASE IN THE GENERAL POPULATION

ADULTS OR MIXED POPULATION: 1 to 17/100,000/year

CHILDREN

2 to 51/100,000/yearIn one of the studies, a stratified analysis showed that there was a higher incidence of celiac disease in younger children compared to older children, i.e., 51 cases/100,000/year in 0 to 2 year-olds, 33/100,000/year in 2 to 5 year-olds, and 10/100,000/year in children 5 to 15 years old.

PREVALENCE OF CELIAC DISEASE IN THE GENERAL POPULATION

The prevalence of celiac disease reported in population-based studies identified in the 2004 systematic review varied between 0.14% and 1.87% (median: 0.47%, interquartile range: 0.25%, 0.71%). According to the authors of the review, the prevalence did not vary by age group, i.e., adults and children.

PREVALENCE OF CELIAC DISEASE IN HIGH RISK SUBJECTS

Type 1 diabetes (adults and children): 1 to 11%AUTOIMMUNE THYROID DISEASE: 2.9 to 3.3%FIRST DEGREE RELATIVES OF PATIENTS WITH CELIAC DISEASE: 2 to 20% PREVALENCE OF CELIAC DISEASE IN SUBJECTS WITH SYMPTOMS CONSISTENT WITH THE DISEASE: The prevalence of celiac disease in subjects with symptoms consistent with the disease varied widely among studies, i.e., 1.5% to 50% in adult studies, and 1.1% to 17% in pediatric studies. Differences in prevalence may be related to the referral pattern as the authors of a systematic review noted that the prevalence tended to be higher in studies whose population originated from tertiary referral centres compared to general practice.

RESEARCH QUESTIONS

What is the sensitivity and specificity of serologic tests in the diagnosis celiac disease?What is the clinical validity of serologic tests in the diagnosis of celiac disease? The clinical validity was defined as the ability of the test to change diagnosis.What is the clinical utility of serologic tests in the diagnosis of celiac disease? The clinical utility was defined as the impact of the test on decision making.What is the budget impact of serologic tests in the diagnosis of celiac disease?What is the cost-effectiveness of serologic tests in the diagnosis of celiac disease?

METHODS

LITERATURE SEARCH

A literature search was performed on November 13(th), 2009 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1(st) 2003 and November 13(th) 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology. Inclusion Criteria Inclusion CriteriaExclusion CriteriaStudies that evaluated diagnostic accuracy, i.e., both sensitivity and specificity of serology tests in the diagnosis of celiac disease.Study population consisted of untreated patients with symptoms consistent with celiac disease.Studies in which both serologic celiac disease tests and small bowel biopsy (gold standard) were used in all subjects.Systematic reviews, meta-analyses, randomized controlled trials, prospective observational studies, and retrospective cohort studies.At least 20 subjects included in the celiac disease group.English language.Human studies.Studies published from 2000 on.Clearly defined cut-off value for the serology test. If more than one test was evaluated, only those tests for which a cut-off was provided were included.Description of small bowel biopsy procedure clearly outlined (location, number of biopsies per patient), unless if specified that celiac disease diagnosis guidelines were followed.Patients in the treatment group had untreated CD.Studies on screening of the general asymptomatic population.Studies that evaluated rapid diagnostic kits for use either at home or in physician's offices.Studies that evaluated diagnostic modalities other than serologic tests such as capsule endoscopy, push enteroscopy, or genetic testing.Cut-off for serologic tests defined based on controls included in the study.Study population defined based on positive serology or subjects pre-screened by serology tests.Celiac disease status known before study enrolment.Sensitivity or specificity estimates based on repeated testing for the same subject.Non-peer-reviewed literature such as editorials and letters to the editor.

POPULATION

The population consisted of adults and children with untreated, undiagnosed celiac disease with symptoms consistent with the disease.

SEROLOGIC CELIAC DISEASE TESTS EVALUATED

Anti-gliadin antibody (AGA)Anti-endomysial antibody (EMA)Anti-tissue transglutaminase antibody (tTG)Anti-deamidated gliadin peptides antibody (DGP)Combinations of some of the serologic tests listed above were evaluated in some studiesBoth IgA and IgG antibodies were evaluated for the serologic tests listed above.

OUTCOMES OF INTEREST

SensitivitySpecificityPositive and negative likelihood ratiosDiagnostic odds ratio (OR)Area under the sROC curve (AUC)Small bowel biopsy was used as the gold standard in order to estimate the sensitivity and specificity of each serologic test.

STATISTICAL ANALYSIS

Pooled estimates of sensitivity, specificity and diagnostic odds ratios (DORs) for the different serologic tests were calculated using a bivariate, binomial generalized linear mixed model. Statistical significance for differences in sensitivity and specificity between serologic tests was defined by P values less than 0.05, where "false discovery rate" adjustments were made for multiple hypothesis testing. The bivariate regression analyses were performed using SAS version 9.2 (SAS Institute Inc.; Cary, NC, USA). Using the bivariate model parameters, summary receiver operating characteristic (sROC) curves were produced using Review Manager 5.0.22 (The Nordiac Cochrane Centre, The Cochrane Collaboration, 2008). The area under the sROC curve (AUC) was estimated by bivariate mixed-efects binary regression modeling framework. Model specification, estimation and prediction are carried out with xtmelogit in Stata release 10 (Statacorp, 2007). Statistical tests for the differences in AUC estimates could not be carried out. The study results were stratified according to patient or disease characteristics such as age, severity of Marsh grade abnormalities, among others, if reported in the studies. The literature indicates that the diagnostic accuracy of serologic tests for celiac disease may be affected in patients with chronic liver disease, therefore, the studies identified through the systematic literature review that evaluated the diagnostic accuracy of serologic tests for celiac disease in patients with chronic liver disease were summarized. The effect of the GFD in patiens diagnosed with celiac disease was also summarized if reported in the studies eligible for the analysis.

SUMMARY OF FINDINGS

PUBLISHED SYSTEMATIC REVIEWS: Five systematic reviews of studies that evaluated the diagnostic accuracy of serologic celiac disease tests were identified through our literature search. Seventeen individual studies identified in adults and children were eligible for this evaluation. (ABSTRACT TRUNCATED)

Primary biliary cirrhosis: What do autoantibodies tell us?

Primary biliary cirrhosis (PBC) is a chronic, progressive, cholestatic, organ-specific autoimmune disease of unknown etiology. It predominantly affects middle-aged women, and is characterized by autoimmune-mediated destruction of small- and medium-size intrahepatic bile ducts, portal inflammation and progressive scarring, which without proper treatment can ultimately lead to fibrosis and hepatic failure. Serum autoantibodies are crucial tools for differential diagnosis of PBC. While it is currently accepted that antimitochondrial antibodies are the most important serological markers of PBC, during the last five decades more than sixty autoantibodies have been explored in these patients, some of which had previously been thought to be specific for other autoimmune diseases.

Antibodies against deamidated gliadin peptides identify adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase

BACKGROUND

This study was done to evaluate the diagnostic utility of antibodies against deamidated gliadin peptides compared to traditional markers for coeliac disease.

AIM

To evaluate diagnostic utility of antibodies against deamidated gliadin peptide (DGP).

METHODS

Sera from 176 adults, referred for endoscopy without previous analysis of antibodies against tissue transglutaminase (tTG) or endomysium (EmA), were retrospectively analysed by ELISAs detecting IgA/IgG antibodies against DGP or a mixture of DGP and tTG, and compared with IgA-tTG and EmA. Seventy-nine individuals were diagnosed with coeliac disease.

RESULTS

Receiver operating characteristic analyses verified the manufacturers' cut-off limits except for IgA/IgG-DGP/tTG. In sera without IgA deficiency, the sensitivity was higher for IgA/IgG-DGP (0.85-0.87) compared with IgA-tTg (0.76) and EmA (0.61). All tests showed high specificity (0.95-1.00). Eighteen coeliac disease-sera were negative regarding IgA-tTG, nine of which were positive for IgA/IgG-DGP. Sera from coeliac disease-patients >70 years were more often negative for IgA-tTG (50%) and IgA/IgG-DGP (36%) than younger patients (15% and 8% respectively) (P < 0.01). Three of the four IgA-deficient patients were positive in the IgA/IgG-DGP assay.

CONCLUSIONS

In this study of patients unselected regarding IgA-tTg/EmA, thus unbiased in this respect, IgA/IgG-DGP identified adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase. Serology is often negative in elderly patients with coeliac disease; a small bowel biopsy should therefore be performed generously before coeliac disease is excluded.

Celiac G+ antibody assay for the detection of autoantibodies in celiac disease

Celiac disease (CD) affects approximately 1% of the population and may present with varied symptomatic as well as asymptomatic clinical manifestations. Simple methods of detecting CD such as serum antibody tests have helped in the early identification of the disease thus preventing serious complications of the disorder. Our objective is to develop specific and sensitive immunoassays that are reliable in the detection of CD. To this end, immunoassays were developed for the detection of IgG and IgA antibodies to gliadin using synthetic peptides. Over 200 serum samples were included in the study from individuals with CD submitted for endomysial (EMA) and tissue transglutaminase (tTG) antibody tests as well as from disease controls and healthy normals. To examine the reliability of the Celiac G+ antibody test in comparison with EMA, a test with higher sensitivity and specificity, samples with low and high EMA titers were included in the study. Comparative evaluations of the Celiac G+ antibody assay were made with EMA and another commercially available gliadin peptide assay along with tTG antibody assays. The data show that as the EMA levels increased the sensitivity of detection of antibodies to synthetic peptides on both systems increased, reaching 100% at EMA titers greater than 160. The diagnostic performance of the newly developed Celiac G+ synthetic gliadin peptide assay is significantly superior in comparison with another available gliadin peptide immunoassay. Overall, the diagnostic performance of the Celiac G+ assay for IgA and IgG reached a sensitivity of 80% and 90% respectively in comparison with EMA. Similar comparison of the EMA positivity to the other available synthetic peptide immunoassay yielded sensitivities of 59% (IgA) and 75% (IgG). The specificity of the Celiac G+ antibody assay for IgA and IgG was 90-95% as compared to the other similar assay with specificity of 88-90%. In conclusion, the performance of the recently developed Celiac G+ ELISA is superior in both its sensitivity and specificity in comparison with other available synthetic gliadin peptide immunoassays. Furthermore, the IgG Celiac G+ antibody test and IgA tTG antibody test used in combination is an excellent screening algorithm for suspected cases of celiac disease.

Increased prevalence of anti-gliadin antibodies and anti-tissue transglutaminase antibodies in children with cerebral palsy

AIM AND OBJECTIVE

The aim of the study was to investigate whether there is any association between cerebral palsy (CP) and celiac disease (CD) in children.

PATIENTS AND METHODS

Ninety children between 18 months and 18 years of age (median 9 years) with CP were included. Antibodies (IgA and IgG) against gliadin (AGA), endomysium (EMA), and tissue transglutaminase (tTG) were measured. Children with elevated levels of these antibodies were offered a small-bowel biopsy.

RESULTS

Thirty-nine children showed an elevated level of 1 or more of the tested antibodies (43%). None had raised EMA antibodies. Presence of tetraplegia or dyskinesia was associated with increased antibody levels (P=0.045), as was a more severe functional type of CP (P=0.008). Children with elevated antibodies had a lower body weight (P=0.049), height (P=0.041), and body mass index (BMI) (P=0.014). Small-bowel biopsies were performed in 27 out of 39 children; 1 had CD and 2 had intraepithelial lymphocytosis.

CONCLUSIONS

A large number of children with CP had elevated AGA and/or anti-tTG. Because these elevations were associated with lower weight, height, and BMI, it seemed of interest to speculate on how these findings correlated to CP and CD. However, we found no correlation between CP and CD.

Celiac sprue: a unique autoimmune disorder

Celiac sprue (CS) is a gluten-sensitive enteropathy with many autoimmune features. CS involves multiple organs through immune and nonimmune processes, and is frequently associated with other autoimmune disorders. This article reviews the co-occurrence of CS with autoimmune disorders of the cutaneous, nervous, endocrine, musculoskeletal, gastrointestinal and cardiovascular systems. The types of autoimmune disorders associated with CS and the prevalence of CS in other autoimmune disorders are also discussed. A brief review of the literature on the potential mechanisms behind these associations and the therapeutic effects of a gluten-free diet for autoimmune comorbidities in CS is also provided.

Liver involvement in celiac disease

Celiac disease is a chronic immune-mediated disorder that may affect several organs. Liver abnormalities are common extraintestinal manifestations of celiac disease. Isolated hypertransaminasemia, with mild or nonspecific histologic changes in the liver biopsy, also known as ''celiac hepatitis'', is the most frequent presentation of liver injury in celiac disease. Both, histologic changes and liver enzymes reverse to normal after treatment with a gluten-free diet in most patients. Celiac disease may also be associated with severe forms of liver disease and/or coexist with other chronic liver disorders (i.e., autoimmune liver diseases). The mechanisms underlying liver injury in celiac disease are poorly understood. Predisposition to autoimmunity by shared genetic factors (i.e., human leukocyte antigen [HLA] genes) as well as the systemic effects of abnormal intestinal permeability, cytokines, autoantibodies, and/or other yet undefined biologic mediators induced by gluten exposure in susceptible persons may play a pathogenic role. The aims of this article are: 1) to review the spectrum of liver injury related to celiac disease and 2) to understand the clinical implications of celiac disease in patients with chronic liver disorders.

Histological abnormalities of the small bowel mucosa in cirrhosis and portal hypertension

AIM: To study the small bowel (SB) mucosa on biopsy in cirrhotic patients with portal hypertension and in non-cirrhotic controls and grade findings according to the Marsh criteria.

METHODS: We prospectively enrolled 51 consecutive patients undergoing an upper endoscopy for their routine medical care. Twenty five patients with cirrhosis and portal hypertension were compared to 26 controls. We obtained coeliac serology and multiple upper small bowel biopsies on all 51 patients. A GI pathologist interpreted biopsies and graded findings according to the Marsh criteria. We assessed equivalence in Marsh grade between cirrhotic and non-cirrhotic controls using the Mann-Whitney test for equivalence.

RESULTS: Gender, ethnicity and age were similar between both groups. Marsh grades were equivalent between the groups. Grade of 0 was present in 96% and grade of 1 was present in 4% of both groups and there was no villus atrophy or decrease in villus/crypt ratio in patients with portal hypertension.

CONCLUSION: This study provides evidence for the lack of villus atrophy in patients with cirrhosis and portal hypertension, and supports the continuous reliance on the Marsh criteria when the diagnosis of coeliac disease is to be made in the presence of cirrhosis.

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.