Evaluation of the Usefulness of a Serological Test for Diagnosis of Celiac Disease Simultaneously Detecting Specific Antibodies and Total IgA

Abstract

The diagnosis of celiac disease (CD) at the first diagnostic step requires the detection of specific class A antibodies to tissue transglutaminase type-2 (TG2 IgA) and the measurement of total immunoglobulin A (tIgA) to exclude IgA deficiency. The aim of the study was to evaluate the new quantitative immunoassay panel allowing for the detection of celiac-specific antibodies with the simultaneous determination of tIgA from the same sample of blood at one time. This retrospective study included 104 pediatric patients divided into groups with recognized CD and IgA deficiency (n = 20; 19%), immunocompetent children with CD (n = 28; 27%), children with IgA deficiency and without CD (n = 28; 27%), and the control group of immunocompetent children without CD (n = 28; 27%). Intestinal biopsy with histopathological evaluation (except five patients with CD who were diagnosed without biopsy) and measurement of reference celiac specific antibodies were performed in all children. Multiparametric quantitative immunoassay Polycheck® Celiac IgA plus total IgA test was used to evaluate its usefulness in CD screening and IgA deficiency diagnosis. The statistical analysis showed the high sensitivity and specificity of both TG2 IgA and tIgA on the multiparametric panel (sensitivity 96% and 100%; specificity 100% and 79%, respectively). The accuracy and area under the ROC curve for tIgA were 0.904 and 0.955, while for TG2 IgA they were 0.982 and 1.000, respectively. Although the sensitivity of IgA antibodies against deaminated gliadin peptides was low (20%), the specificity reached 100%. The study showed that Polycheck® Celiac IgA plus total IgA test is a specific and sensitive tool for simultaneous serological CD screening and recognition of IgA deficiency.

The Opinion of Polish Coeliac Patients on the Knowledge of Medical Professionals and Support Groups about Coeliac Disease—A Pilot Study

“…Serology is the first step, before biopsy, in the CD diagnostic process in children and adults. The concentration of specific antibodies for CD decreases with strict adherence to the GFD [12]. After the exclusion of gluten, the intestinal villi are also restored.…”

The Occurrence of Gluten-Related Antibodies, Sensitization to Selected Food Allergens, and Antibodies against Intrinsic Factor in Adult Patients with Diarrhea-Predominant Irritable Bowel Syndrome

“…Antibodies in IgA class (Polycheck ® Celiac IgA plus total IgA, Biocheck, GmbH, Münster, Germany) and IgG class (Polycheck ® Celiac IgG, Biocheck, GmbH, Münster, Germany) were assed with the use of multiparametric immunoassays. Polycheck ® Celiac IgA plus total-IgA test allowed detection of concentration of total IgA and antibodies against human recombinant TTG2 (TTG2 IgA) and DGP (DGP IgA) [23]. Using Polycheck ® Celiac IgG, TTG2 IgG, DGP IgG, and IF IgG antibodies were detected.…”

“…Using Polycheck ® Celiac IgG, TTG2 IgG, DGP IgG, and IF IgG antibodies were detected. The concentrations of antibodies were measured according to manufacturer protocols, described in detail in our previous studies [23,39]. After gentle defrosting, each serum sample was diluted 1:100 and, next, samples examined individually (but simultaneously) for specific set of antibodies.…”

“…In genetically predisposed individuals who have genes encoding HLA-DQ2/-DQ8 molecules, DGP strongly binds to these molecules on antigen-presenting cells, activating specific T cells, which, in turn, induce B cells through the production of antibodies directed against TTG2 (TTG2 antibodies) and DGP (DGP antibodies) [21]. The presence of TTG2 antibodies in the immunoglobulin (Ig) A class is a specific marker of autoimmune processes in CD and, currently, these antibodies are referred to as CD specific autoantibodies with high sensitivity and specificity [22,23]. In contrast to TTG2 autoantibodies, which are highly CD-specific, the presence of DGP antibodies generally indicates contact with gluten, so it can be a very good marker for following a gluten-free diet (GFD) in CD patients [24].…”

Osteoporosis and Celiac Disease: Updates and Hidden Pitfalls

“…The European Society for the Study of Celiac Disease (ESsCD) guidelines suggest that IgA-transglutaminase type 2 (IgA-TG2) antibody is the best single test for CD detection at any age, along with total IgA levels, which should be always assessed to rule out IgAdeficiency, which occurs in up to 8% of CD patients [14]. It is of paramount importance that all serologic tests are performed while patients are on a gluten-containing diet [15].…”