Tissue transglutaminase autoantibody enzyme-linked immunosorbent assay in detecting celiac disease

Abstract

Calcium-activated tissue transglutaminase autoantibody ELISA is highly accurate in detecting untreated celiac disease. Tissue transglutaminase seems to be the target self-antigen for endomysial antibodies.

Tissue Transglutaminase Autoantibodies in Patients with Non-Hodgkin’s Lymphoma

“…Furthermore, pretreatment of CD sera with t-TG seems to eliminate the endomysial staining pattern in human umbilical cord [1, 2], suggesting that t-TG could be the previously unknown endomysial autoantigen. To date, the clinical studies on IgA anti-tTG determination have also indicated a very high specificity of this ELISA assay for CD diagnosis: Dieterich et al [1]did not find false-positive results in a small control group including subjects with inflammatory bowel disease or Sjögren’s syndrome; Troncone et al [3]found one ‘false-positive’ anti-tTG result out of 63 controls with various gastrointestinal diseases, but this patient also had positive serum anti-endomysial IgA and a high density of γ/δ-positive intraepithelial lymphocytes in the intestinal biopsy, clearly suggesting that he was a ‘latent celiac’ [11, 12].…”

“…To date, the clinical studies on IgA anti-tTG determination have also indicated a very high specificity of this ELISA assay for CD diagnosis: Dieterich et al [1]did not find false-positive results in a small control group including subjects with inflammatory bowel disease or Sjögren’s syndrome; Troncone et al [3]found one ‘false-positive’ anti-tTG result out of 63 controls with various gastrointestinal diseases, but this patient also had positive serum anti-endomysial IgA and a high density of γ/δ-positive intraepithelial lymphocytes in the intestinal biopsy, clearly suggesting that he was a ‘latent celiac’ [11, 12]. Finally, Sulkanen et al [2]in the largest study on the clinical use of anti-tTG assay published to date, showed 13 ‘false positive’ results out of 207 controls without CD, but the authors themselves suggested that these subjects could ‘belong to the entity of latent celiac disease’.…”

“…This hypothesis is also in agreement with the recent report of 49 patients with type 1 diabetes who were positive for anti-tTG antibodies, assayed by radiobinding assay with recombinant human t-TG, but negative for EmA [17]. Third, and in our opinion the most probable hypothesis, it is possible that the false positive anti-tTG results we observed depend on the nature of the antigen of the ELISA method we used; in fact, this test is based on tTG which is extracted from guinea pig liver and it must be remembered that Sigma tTG is composed of at least 14 different components [18]; thus, it is possible that in the sera of our patients there could be antibodies for protein antigens from the liver matrix, probably common to humans; in any case, it must be remembered that most of the gastroenterological studies published to date [2, 3, 4, 19]which reported a very high specificity of anti-tTG determination for CD diagnosis were performed with the same ELISA we used in the present study, based on tTG on guinea pig liver.…”

“…Tissue transglutaminase (tTG) has recently been identified as the main autoantigen recognized by endomysial antibodies in celiac disease (CD) patients [1]and this has permitted the use of an ELISA test to detect the presence in the serum of autoantibodies, anti-tTG, specific for the diagnosis of CD [1, 2, 3, 4]. Furthermore, as the ELISA test is simpler and less expensive than the immunofluorescence technique traditionally used for the detection of anti-endomysial (EmA) antibodies, the anti-tTG ELISA has opened up new perspectives for the mass screening of CD.…”

“…Furthermore, as the ELISA test is simpler and less expensive than the immunofluorescence technique traditionally used for the detection of anti-endomysial (EmA) antibodies, the anti-tTG ELISA has opened up new perspectives for the mass screening of CD. All the studies on the clinical usefulness of anti-tTG determination have reported no or very rare false-positive results for CD diagnosis [1, 2, 3, 4], and when positive results have been found in patients with normal intestinal histology the hypothesis of a latent CD has been advanced [2, 3]. Now we report 2 cases of anti-tTG positivity in patients with non-Hodgkin’s lymphoma (NHL) without evidence of CD.…”