An initial assessment of the involvement of transglutaminase2 in eosinophilic bronchitis using a disease model developed in C57BL/6 mice.

The detailed pathogenesis of eosinophilic bronchitis (EB) remains unclear. Transglutaminase 2 (TG2) has been implicated in many respiratory diseases including asthma. Herein, we aim to assess preliminarily the relationship of TG2 with EB in the context of the development of an appropriate EB model through ovalbumin (OVA) sensitization and challenge in the C57BL/6 mouse strain. Our data lead us to propose a 50 µg dose of OVA challenge as appropriate to establish an EB model in C57BL/6 mice, whereas a challenge with a 400 µg dose of OVA significantly induced asthma. Compared to controls, TG2 is up-regulated in the airway epithelium of EB mice and EB patients. When TG2 activity was inhibited by cystamine treatment, there were no effects on airway responsiveness; in contrast, the lung pathology score and eosinophil counts in bronchoalveolar lavage fluid were significantly increased whereas the cough frequency was significantly decreased. The expression levels of interleukin (IL)-4, IL-13, IL-6, mast cell protease7 and the transient receptor potential (TRP) ankyrin 1 (TRPA1), TRP vanilloid 1 (TRPV1) were significantly decreased. These data open the possibility of an involvement of TG2 in mediating the increased cough frequency in EB through the regulation of TRPA1 and TRPV1 expression. The establishment of an EB model in C57BL/6 mice opens the way for a genetic investigation of the involvement of TG2 and other molecules in this disease using KO mice, which are often generated in the C57BL/6 genetic background.

Is Endoscopic Assessment of the Esophagus and Stomach Enough to Determine the Need for Biopsy at These Sites in Pediatric Patients Undergoing Endoscopy for Elevated TTG?

OBJECTIVES: The goal of our study was to determine whether visual assessment of the esophagus and stomach could predict abnormal histology and determine the frequency of interventions based on biopsies in patients undergoing endoscopy for elevated tissue transglutaminase immunoglobulin A antibody (TTG). METHODS: Pathology records were searched for patients with biopsy performed for elevated TTG. Pathology report, endoscopy report, and follow-up were obtained and slides from the duodenum reviewed. Pathology was considered gold standard for sensitivity and specificity calculations. RESULTS: 240 patients were included. 215 patients had esophageal biopsies performed. Esophageal endoscopic visual assessment had sensitivity of 47% and specificity of 93% for abnormal histology. 16(7%) patients had therapy or referral related to results and, of these, 6(38%) had visually normal endoscopy. 237 biopsies were performed of stomach. Gastric endoscopic visual assessment had a sensitivity and specificity of 20% and 87%. 24(10%) patients had therapy based on findings and, of these, 12 (50%) had visually normal endoscopy. CONCLUSIONS: Endoscopic assessment of esophagus and stomach has low sensitivity and high specificity for pathologic abnormalities when indication for endoscopy is elevated TTG. When endoscopy is visually normal clinical interventions based on biopsy are rare, and foregoing biopsy may be considered.

Celiac Dietary Adherence Test and Standardized Dietician Evaluation in Assessment of Adherence to a Gluten-Free Diet in Patients with Celiac Disease.

Adherence to a gluten-free diet (GFD) is currently the mainstay of treatment strategy for celiac disease (CD). The aim of our study was measuring a GFD adherence in CD patients using two newly validated methods of dietary assessment-Standardized Dietician Evaluation (SDE) and the Celiac Dietary Adherence Test (CDAT). Ninety-two adults with CD were evaluated by a registered dietitian with extensive experience with the use of SDE and CDAT. Duodenal biopsy was performed and blood was drawn for serum anti-endomysial, anti-deamidated gliadin peptide and anti-tissue transglutaminase antibodies in forty four of those patients. The results of CDAT and SDE were very convergent, but SDE scores better correlated with serologic and histologic findings. As many as 24-52% of study participants did not adhere well enough to a GFD. Insufficient adherence to a GFD in CD patients is still a significant problem. The knowledge about gluten content in food ingredients and additives is very low among adults with CD. SDE is the most accurate method in assessing compliance with a GFD and is especially helpful in determining hidden sources of gluten. The CDAT may be a fast tool for screening for a GFD adherence in CD patients.

Adherence to a Gluten-free Diet: Assessment by Dietician Interview and Serology.

We aimed to determine whether tissue transglutaminase (tTG) autoantibody positivity was associated with dietitian-assessed adherence to a gluten-free diet in pediatric patients with celiac disease and identify areas where adherence falters. We reviewed the records of children with celiac disease who had a standardized evaluation of adherence by a registered dietitian. A negative tTG value was not associated with good adherence (P = NS). Adherent and nonadherent children differed with respect to purposeful and accidental gluten exposure (P < 0.0001), knowledge (P = 0.003), cross-contact (P = 0.003), potential exposure via medications and cosmetics (P = 0.004), and potential exposure while at restaurants (P < 0.0001), but not with respect to potential exposure at school (P = NS). Based on our findings, we suggest that negative tTG levels are not necessarily indicative of good adherence to a gluten-free diet in pediatric patients with celiac disease. A separate assessment of adherence is needed focusing on knowledge, behavior while dining out, and intent to adhere.

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.

Seroprevalence of celiac disease among United Arab Emirates healthy adult nationals: a gender disparity.

AIM: To determine celiac disease (CD) prevalence and associated manifestations or risk factors in healthy adult Emiratis. METHODS: It is a cross-sectional prospective study, recruiting 1197 (573 women and 624 men) healthy Emiratis between September 2007 and April 2008 among those who went to Al Ain Hospital to undertake the prenuptial examination. Test for anti-tissue transglutaminase (tTG) IgA antibodies was used for CD diagnosis. Subjects with positive results in the anti tTG antibodies assay were also tested for anti-endomysial (EMA) IgA antibodies. A structured interview was used to collect basic demographic and clinical recall data including: information on name, contact address, age, gender, education status, previous diagnosis of CD, diagnosis of CD in 1(st) degree relatives and history of "chronic diarrhea, anemia, headache, hepatitis, diabetes, tumor, and thyroid disorder". RESULTS: Fourteen blood samples (1.17%; 14/1197) were seropositive for CD. The latent CD seropositive patients were 13 women and 1 man and therefore the seroprevalence of CD was 1:86 (14/1197) for adult Emiratis: 1:44 (13/573) for women and 1:624 for men. Binary logistic regression revealed that history of chronic anemia (crude OR = 7.09; 95%CI: 2.32-21.61; P = 0.003) and being a woman (OR = 14.46; 95%CI: 1.89-110.91; P = 0.001) were associated with CD seropositivity. Whereas, the thyroid disorder showed a positive association with CD seropositivity that approach statistical significance (OR = 11.30; 95%CI: 1.32-96.95; P = 0.09) and therefore was included in the multiple logistic regression analysis, which showed that CD seropositivity is independently associated only with history of chronic anemia (OR = 4.58; 95%CI: 1.45-14.48; P = 0.01) and being a woman person (OR = 10.47; 95%CI: 1.33-82.14; P = 0.026). CONCLUSION: Compared to men the CD seroprevalence among women was remarkably higher. The CD association with women and chronic anemia is of importance from a public health perspective.

Serological assessment for celiac disease in IgA deficient adults.

PURPOSE: Selective immunoglobulin A deficiency is the most common primary immunodeficiency disorder that is strongly overrepresented among patients with celiac disease (CD). IgG antibodies against tissue transglutaminase (tTG) and deamidated gliadin peptides (DGP) serve as serological markers for CD in IgA deficient individuals, although the diagnostic value remains uncertain. The aim of this study was to investigate the prevalence of these markers in a large cohort of IgA deficient adults with confirmed or suspected CD and relate the findings to gluten free diet. METHODS: Sera from 488,156 individuals were screened for CD in seven Swedish clinical immunology laboratories between 1998 and 2012. In total, 356 out of 1,414 identified IgA deficient adults agreed to participate in this study and were resampled. Forty-seven IgA deficient blood donors served as controls. Analyses of IgG antibodies against tTG and DGP as well as HLA typing were performed and a questionnaire was used to investigate adherence to gluten free diet. Available biopsy results were collected. RESULTS: Out of the 356 IgA deficient resampled adults, 67 (18.8%) were positive for IgG anti-tTG and 79 (22.2%) for IgG anti-DGP, 54 had biopsy confirmed CD. Among the 47 IgA deficient blood donors, 4 (9%) were positive for IgG anti-tTG and 8 (17%) for anti-DGP. Four were diagnosed with biopsy verified CD, however, 2 of the patients were negative for all markers. Sixty-eight of 69 individuals with positive IgG anti-tTG were HLA-DQ2/DQ8 positive whereas 7 (18.9%) of the 37 individuals positive for IgG anti-DGP alone were not. CONCLUSIONS: IgG anti-tTG seems to be a more reliable marker for CD in IgA deficient adults whereas the diagnostic specificity of anti-DGP appears to be lower. High levels of IgG antibodies against tTG and DGP were frequently found in IgA deficient adults despite adhering to gluten free diet.

Proteomic analyses lead to a better understanding of celiac disease: focus on epitope recognition and autoantibodies.

Proteomic technologies are being used with increasing frequency in the scientific community. In this review, we have highlighted their use in celiac disease (CD). The available techniques, which include two-dimensional (2D) gel electrophoresis, mass spectrometry, and antibody and tissue arrays, have been used to identify proteins or changes in protein expression specific to gut tissue from patients with CD. A number of studies have employed proteomic methodologies to determine the diagnostic biomarkers in body fluids or to examine changes in protein expression and posttranslational modifications during signaling. A fast technological development of these methods, along with the combination of classic techniques with proteomics, will lead to new discoveries, which will consent a better understanding of the pathogenesis of CD.

Tissue transglutaminase antibodies in celiac disease: assessment of a commercial kit.

OBJECTIVE: Tissue transglutaminase was identified as the autoantigen eliciting endomysial antibody. A homemade enzyme-linked immunosorbent assay (ELISA)-based test was recently developed to determine quantitative titers of IgA antitissue transglutaminase antibody. Our objective in this study was to assess the suitability of a newly developed commercial kit for quantitative determination of antibody in patients with untreated celiac disease. MATERIALS: We tested serum samples from 79 untreated celiac patients, 42 healthy blood donors, and 18 patients with nonceliac intestinal disorders evaluated in two different centers. Samples were tested for antitissue transglutaminase, and antiendomysial and antigliadin antibodies in the center where diagnosis was performed. To assess interlaboratory variability of methods, 24 samples randomly selected were blindly tested in both centers. Antitissue transglutaminase antibodies were determined using a commercial kit (INOVA Diagnostics, Inc., San Diego, CA). RESULTS: Untreated celiac patients had significantly higher titers of antitissue transglutaminase than healthy and disease controls (p < 0.00001). According to the cut-off provided by the manufacturers (20 AU/mL), overall sensitivity was 92% (85% for one center and 100% for the other) and specificity was 98% (100% and 95%, respectively). Antiendomysial antibody was 86% sensitive and 100% specific. Discordance between antitissue transglutaminase and antiendomysial antibodies was detected in 13% of patients. Although two antitissue transglutaminase-negative cases had a positive antiendomysial antibody, the inverse situation was found in eight cases. A blind determination of antitissue transglutaminase on the same samples evidenced a good agreement (kappa statistic: 0.66) between both centers when assessment was qualitative (based on the decision of positive or negative). Although correlation of titers for both determinations was highly significant (r: 0.902, p < 0.00001), a very wide interlaboratory variability (median: 50%) was detected when absolute values were considered. CONCLUSIONS: The quantitative determination of antitissue transglutaminase using a commercial kit was highly sensitive and specific for detection of celiac disease. We observed an incomplete overlapping with antiendomysial antibody. The very high variability of values between laboratories still remains to be solved so as to propose the commercial ELISA assay for the screening of celiac disease.