Diagnostic Accuracy of IgA Anti-Tissue Transglutaminase Antibody Assays in Celiac Disease Patients with Selective IgA Deficiency

2007 ◽  
Vol 1109 (1) ◽  
pp. 212-220 ◽  
Author(s):  
D. VILLALTA ◽  
M. G. ALESSIO ◽  
M. TAMPOIA ◽  
E. TONUTTI ◽  
I. BRUSCA ◽  
...  
2004 ◽  
Vol 50 (11) ◽  
pp. 2125-2135 ◽  
Author(s):  
Britta Van Meensel ◽  
Martin Hiele ◽  
Ilse Hoffman ◽  
Severine Vermeire ◽  
Paul Rutgeerts ◽  
...  

Abstract Background: Anti-tissue transglutaminase (tTG) assays that use human tTG as antigen have recently become available. We evaluated commercially available assays with human tTG antigen to estimate their diagnostic accuracies and to determine whether they agree sufficiently to be used interchangeably. Methods: Ten commercially available second-generation anti-tTG assays were evaluated. The following populations were studied: celiac disease (CD) patients at the time of diagnosis without (n = 70) or with (n = 5) IgA deficiency; diseased controls (n = 70); and CD patients without (n = 28) or with (n = 2) IgA deficiency during follow-up. All individuals included in the study underwent intestinal biopsy. Technical performance (linearity, interference, precision, correlation, and agreement) and diagnostic accuracy (sensitivity and specificity) were compared. Anti-gliadin and anti-endomysium antibodies were also measured. Results: IgA anti-tTG results correlated well overall, but numerical values differed. Diagnostic sensitivity ranged between 91% and 97% and specificity between 96% and 100%. These were higher than the sensitivity and specificity of the IgA endomysium assay and the IgA gliadin assay. Generally, IgG anti-tTG was less sensitive but more specific than IgG anti-gliadin for the diagnosis of CD in the small group of IgA-deficient patients. Conclusions: Overall diagnostic performance of IgA tTG assays is acceptable and comparable among the different assays, but numerical values differ. Standardization is needed.


2005 ◽  
Vol 51 (6) ◽  
pp. 1014-1016 ◽  
Author(s):  
Eloy Fernández ◽  
Carlos Blanco ◽  
Sara García ◽  
Angeles Dieguez ◽  
Sabino Riestra ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Ider Oujamaa ◽  
Majda Sebbani ◽  
Lahcen Elmoumou ◽  
Aïcha Bourrahouate ◽  
Rabiy El Qadiry ◽  
...  

Objective. We aimed to determine the prevalence of specific auto-antibodies to celiac disease (CD) in Moroccan type 1 diabetic (T1D) patients and compare the clinical and biological characteristics of seropositive and seronegative cases. Patients and Methods. A cross-sectional study was carried out on 276 T1D patients including 109 adults and 167 pediatric cases. The screening for CD was performed by an Elisa IgA anti-tissue transglutaminase antibody (tTGA) testing, combined with IgA quantification by nephelometry. Positive-IgA-tTGA cases were secondly tested for anti-endomysial antibodies (EMA) using an immunofluorescence technique, and the IgA deficiency cases were screened for IgG-tTGA. Patients with low positive tTGA titers underwent HLA-DQ2/DQ8 typing. Sociodemographic and clinical data of the patients were collected using a hetero-administered questionnaire. The comparison of clinical and biological data between seropositive and seronegative diabetics was done using independent T, Mann–Whitney U, chi-squared, and Fisher tests, which were considered significant if p value <0.05. Results. The prevalence of CD-specific auto-antibodies was estimated to be 9.1% (IC = 95%), with 25 positive cases in tTGA and EMA testing. Eight cases displayed low titers of IgA-tTGA, among which 4 were positive for HLA-DQ2, 1 for HLA-DQ8, and 1 for both DQ2 and DQ8. The other 2 cases had a biopsy-proven CD. Compared to seronegative patients, seropositive cases had a higher percentage of associated autoimmune disorders (16% vs. 2.4%, p=0.008), with a significant lower height Z-scores (median: −0.90 (−3.93 to 0.95) vs. −0.51 (−4.54 to 2.18), p=0.029) and a higher HbA1c level (median: 11.30% (7.31 to 16.00) vs. 9.30% (4.40 to17.31), p=0.022). Conclusion. The current study gave evidence of a high prevalence of CD specific auto-antibodies in T1D population. The co-existence of these two conditions was associated with a poor glycemic control, a lower height, and other autoimmune diseases. These findings may suggest the necessity of a systematic screening of CD in T1D patients.


2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Kristina Baraba Dekanić ◽  
Ivona Butorac Ahel ◽  
Lucija Ružman ◽  
Jasmina Dolinšek ◽  
Jernej Dolinšek ◽  
...  

Introduction. Celiac disease (CD) is an autoimmune disease triggered by gluten in genetically predisposed individuals. Despite the increasing prevalence of CD, many patients remain undiagnosed. Standard serology tests are expensive and invasive, so several point-of-care tests (POC) for CD have been developed. We aimed to determine the prevalence of CD in first-grade pupils in Primorje-Gorski Kotar County, Croatia, using a POC test. Methods. A Biocard celiac test that detects IgA antibodies to tissue transglutaminase in whole blood was used to screen for celiac disease in healthy first-grade children born in 2011 and 2012 who consumed gluten without restrictions. Results. 1478 children were tested, and none of them were tested positive with a rapid test. In 10 children (0,6%), IgA deficiency has been suspected; only 4 of them agreed to be tested further for total IgA, anti-tTG, and anti-DGP antibodies. IgA deficiency was confirmed in 3 patients, and in all 4 children, CD has been excluded. Conclusion. Our results have not confirmed the usefulness of the POC test in screening the general population of first-grade schoolchildren. Further research is needed to establish the true epidemiology of CD in Primorje-Gorski Kotar County and to confirm the value of the rapid test in comparison with standard antibody CD testing.


2018 ◽  
Vol 23 (suppl_1) ◽  
pp. e14-e14
Author(s):  
Michelle Gould ◽  
Herbert Brill ◽  
Margaret Marcon ◽  
Catharine Walsh

Abstract BACKGROUND Celiac disease (CD) is an autoimmune enteropathy triggered by gliadin. The gold standard for diagnosis is small bowel biopsy. Screening with serologic markers to identify endoscopic candidates is commonly completed by paediatricians. The most common serologic marker used for screening is IgA anti-Tissue Transglutaminase (TTG) antibodies. Antibodies to deamidated gliadin peptide (DGP) is a newer assay with studies demonstrating a diagnostic performance similar to anti-TTG. In Canada, this assay has been added to many laboratory’s celiac screening panels. There is little evidence however regarding the usefulness of an isolated positive anti-DGP result in paediatric patients and no study has systematically assessed the presence of biopsy proven CD in solely anti-DGP positive paediatric patients. OBJECTIVES We sought to determine the positive predictive value of anti-DGP for biopsy proven CD in paediatric patients with negative TTG IgA testing. DESIGN/METHODS A multi-center retrospective review of children referred to three centers in Ontario, Canada between January 2015 and December 2016 who had isolated anti-IgG DGP positive CD serology was completed. To be included, patients required serology positive for DGP IgG and negative for all other celiac serologic tests, as well as a duodenal biopsy while on a gluten-containing diet. The positive predictive value of isolated anti-DGP was calculated. RESULTS A total of 83 patients were identified with anti-DGP positive, anti-TTG negative serology. Of these, 40 patients underwent endoscopy. Only 1 patient had findings consistent with CD on biopsy (Marsh 3B histology), yielding a positive predictive value of 2.5%. This patient was IgA deficient. Amongst the cohort of IgA sufficient patients (N=25), the positive predictive value of anti-DGP serology was 0%. One additional patient who was IgA sufficient had findings in keeping with Marsh 2 histology, but repeat TTG and DGP testing was negative. Five patients were found to be IgA deficient at the time of serologic testing, 25 were IgA sufficient and 10 did not have a measured IgA. CONCLUSION Isolated positive DGP IgG serology has a poor positive predictive value for CD, especially in IgA sufficient individuals. For this reason, DGP IgG testing should not be completed as part of the initial screening for celiac disease in the paediatric population unless a compelling reason, such as IgA deficiency or age under 2 years, is present, in order to prevent unnecessary invasive follow-up testing and costs to patients and the health care system.


2010 ◽  
Vol 56 (3) ◽  
pp. 464-468 ◽  
Author(s):  
Danilo Villalta ◽  
Elio Tonutti ◽  
Christian Prause ◽  
Sibylle Koletzko ◽  
H Holm Uhlig ◽  
...  

AbstractBackground: Assays for IgG antibodies against deamidated gliadin (IgG-anti-dGli) are comparable in performance with tests detecting IgA antibodies against tissue transglutaminase (IgA-anti-tTG) in diagnosing celiac disease (CD). IgA-anti-tTG are absent in IgA deficiency, a condition often associated with CD. In IgA deficiency, IgG-anti-tTG, which have a lower overall diagnostic accuracy, are routinely measured. We examined whether IgG-anti-dGli would be useful for diagnosing CD in patients with IgA deficiency.Methods: We studied 34 IgA-deficient CD patients, 185 IgA-competent newly diagnosed children with CD, 316 children without CD, 400 adult blood donors, and 6 control IgA-deficient individuals without CD. Anti-dGli and anti-tTG were measured by ELISA, and endomysium antibodies (EmA) were measured by immunofluorescence on monkey esophagus (IgA as well as IgG class for all antibodies). We calculated diagnostic sensitivity (percentage of patients above cutoff with 95% CIs) according to age-specific cutoffs for 95% diagnostic specificity and according to cutoffs proposed by the manufacturer of the assays.Results: No IgA-deficient CD patients were positive for any IgA-based antibody assay. Diagnostic sensitivity of IgG-anti-tTG was 91.2% (95% CI 76.3%–97.7%) according to age-specific cutoffs and 82.4% (66.1%–92.0%) according to manufacturer cutoffs. The diagnostic sensitivity of IgG-EmA was 75.8% (58.8%–87.4%) and the sensitivity of IgG-anti-dGli was 88.2% (72.8%–95.9%) according to both cutoffs.Conclusions: IgG-anti-dGli and IgG-anti-tTG have comparable diagnostic sensitivities for IgA-deficient celiac patients. IgG-anti-dGli may be useful for diagnosing CD in IgA-deficient patients.


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