M. Di Tola

Radioimmunoassay to detect antitransglutaminase autoantibodies is the most sensitive and specific screening method for celiac disease

OBJECTIVE:The aim of this study was to establish the most sensitive and specific screening method for celiac disease. We tested three methods based on different principles, which all detect autoantibodies against the same antigen (tissue transglutaminase).METHODS:Sixty-two celiac children at the first biopsy (group 1), 78 celiac children on a gluten-free diet (group 2), 14 celiac children on a gluten-challenge (group 3), and 56 controls with a normal duodenal mucosa (group 4) were studied. The methods used were: 1) radioimmunoprecipitation assay using recombinant tissue transglutaminase (RIA); 2) commercial enzyme immunoassay using guinea pig tissue transglutaminase (ELISA); and 3) indirect immunofluorescence method for detection of antiendomysium antibodies (IF-EMA).RESULTS:RIA antitransglutaminase autoantibodies were detected in 100% of group 1, 43.6% of group 2, 100% of group 3, and none of the control subjects. ELISA antitransglutaminase autoantibodies were detected in 90.3% of group 1, 9% of group 2, 78.6% of group 3, and in none of the control subjects. IF-EMA were detected in 95.2% of group 1, 11.5% of group 2, 92.3% of group 3, and 1.8% of the controls.CONCLUSIONS:Our results demonstrate a very high sensitivity and specificity of the RIA method to detect antitransglutaminase autoantibodies in comparison to ELISA and IF-EMA assays. We can explain this finding with the use of human recombinant antigen and the increased capacity of the RIA method to detect low titers of autoantibodies. If our data are confirmed by studies on larger series, tissue transglutaminase RIA could be proposed as the best screening method for celiac patients.

Identification of a new coeliac disease subgroup: antiendomysial and anti-transglutaminase antibodies of IgG class in the absence of selective IgA deficiency

Abstract. Picarelli A, Di Tola M, Sabbatella L, Mastracchio A, Trecca A, Gabrielli F, Di Cello T, Anania MC, Torsoli A (University of Rome “La Sapienza”, Rome, Italy). Identification of a new coeliac disease subgroup: antiendomysial and anti‐transglutaminase antibodies of IgG class in the absence of selective IgA deficiency. J Intern Med 2001; 249: 181–188.

31-43 Amino Acid Sequence of the a-Gliadin Induces Anti-Endomysial Antibody Production during in Vitro Challenge

BACKGROUND Wheat gliadin is the culprit antigen of coeliac disease (CD). Two short sequences of NH2-terminal portion of gliadin seem to be responsible for CD. Antiendomysial antibodies (EMA), highly sensitive and specific for CD, are detectable in the culture media from treated CD patients, after in vitro challenge with peptic-tryptic (PT) digest of gliadin. In this study we detected EMA production after in vitro challenge with 31-43 peptide. We used 56-68 peptide, lacking toxic sequences, as a negative control. METHODS Duodenal samples from 11 treated CD patients and 9 control patients were cultured with 31-43 and 56-68 peptides and PT gliadin. Indirect immunofluorescence analysis was used for EMA detection. RESULTS EMA were detected in culture media of 10 of 11 specimens challenged with PT-gliadin and in the media of all specimens challenged with 31-43 peptide. No EMA were detectable in any treated patients cultured with 56-68 peptide or with medium alone. No EMA were observed in cultures of control specimens. DISCUSSION The ability of the 31-43 sequence of the alpha-gliadin to induce EMA production suggests its involvement in the pathogenesis of CD. Furthermore, it may be a more useful antigenic substance than PT gliadin for both in vitro and in vivo studies of CD.

Presence of anti-"tissue" transglutaminase antibodies in inflammatory intestinal diseases: an apoptosis-associated event?

Presence of anti-‘tissue’ transglutaminase antibodies in inflammatory intestinal diseases: an apoptosis-associated event?

Anti-endomysial antibody of IgG1 isotype detection strongly increases the prevalence of coeliac disease in patients affected by type I diabetes mellitus

A strong association between type 1 insulin‐dependent diabetes mellitus (IDDM1) and coeliac disease (CD) is well documented, but it is known that prevalence values are underestimated. Serum anti‐endomysial antibodies (EMA), considered diagnostic for CD because of their high sensitivity and specificity, belong to the IgA class, but the existence of EMA of IgG1 isotype in the presence or absence of IgA deficiency was reported. In order to re‐evaluate the occurrence of CD in IDDM1 patients we performed a screening in IDDM1 patients using EMA of both isotypes. Ninety‐four adults affected by IDDM1 (unaffected by CD before enrolling) were enrolled and 83 blood donors as controls. All subjects were on a gluten‐containing diet. Histology and biopsy culture were performed. EMA IgA and IgG1 in sera and culture supernatants were detected. Serum EMA were positive in 13 of 94 IDDM1 patients (13·8%). Six of 13 presented IgA‐EMA, seven of 13 presented IgG1‐EMA. No EMA were found in the control population. Total intestinal atrophy was found in all six patients with serum IgA‐EMA and in five of seven with serum IgG1‐EMA. Diagnosis of CD was confirmed by histology and organ culture in all 13 patients with serum EMA. The prevalence of CD in the patients affected by IDDM1 was 6·4% for IgA‐EMA‐positive and 7·4% for IgG1‐EMA‐positive patients. We confirmed the prevalence of CD in the IDDM1 population obtained with IgA‐EMA screening only (6·4%). This prevalence value increases dramatically to 13·8% when IgG1‐EMA are also used in the screening. We conclude that IgG1‐EMA should also be sought whenever an IDDM1 patient undergoes screening for CD.

Antitissue transglutaminase antibodies in acute coronary syndrome: an alert signal of myocardial tissue lesion?

Background and aim.  Antitransglutaminase, previously considered identical to antiendomysial in coeliac sprue (CS), have been reported in end‐stage heart failure. To clarify the above‐mentioned data, we evaluated these antibodies in a cohort of cardiological patients with respect to troponin I, creatine kinase (CK), MB fraction creatine kinase (CK‐MB mass) and myoglobin.

Letter: Adnab-9 as a potential non-invasive biomarker for prediction of malignancy in coeliac disease.

1. Lebwohl B, Granath F, Ekbom A, et al. Mucosal healing and mortality in coeliac disease. Aliment Pharmacol Ther 2013; 37: 332–9. 2. Moore JK, West SR, Robins G. Advances in celiac disease. Curr Opin Gastroenterol 2011; 27: 112–8. 3. Gibson PR, Shepherd SJ, Tye-Din JA. For celiac disease, diagnosis is not enough. Clin Gastroenterol Hepatol 2012; 10: 900–1. 4. Kaukinen K, Per€aaho M, Lindfors K, et al. Persistent small bowel mucosal villous atrophy without symptoms in celiac disease. Aliment Pharmacol Ther 2007; 25: 1237–45. 5. Herman ML, Rubio-Tapia A, Lahr BD, et al. Patients with celiac disease are not followed up adequately. Clin Gastroenterol Hepatol 2012; 10: 893–9. 6. Haines ML, Anderson RP, Gibson PR. Systematic review: the evidence base for long-term management of coeliac disease. Aliment Pharmacol Ther 2008; 28: 1042–66.

Quantitative analysis of stool losses in adult celiac disease: Use of near-infrared analysis reconsidered

BACKGROUND An attempt has been made to establish whether near-infrared stool analysis is more suitable for quantifying malabsorption than the traditional stool fat analysis. A group of celiac disease (CD) patients was used as index population. METHODS Stool fat, nitrogen, and water were measured with near-infrared analysis of 1- and 3-day stool collections in 96 celiac disease patients on a free diet (in 39 also on gluten-free diet) and in 96 matched controls and 14 patients with latent CD. RESULTS The fecal output of fat, nitrogen, and water was significantly increased in free-diet CD, whereas their percentage content was only slightly modified compared with controls. None of the variables under consideration differed significantly between the 24-h and 72-h stool specimens. CONCLUSION Our data show that the high value of fecal fat, nitrogen, and water, in celiac disease, are mainly due to the fecal weight, whereas the percentage composition of stool does not offer additional diagnostic information. Furthermore, 3-day stool collection is not necessary to confirm or rule out malabsorption in most patients. Near infrared analysis of 24-h specimens is time- and cost-effective and may increase the use of stool analysis and be usefully employed to monitor the clinical follow-up of patients with chronic diarrhea.

Usefulness of the organ culture system in the in vitro diagnosis of Celiac Disease: A multicenter study

OBJECTIVE Diagnosis of coeliac disease is based on the presence of villous atrophy which recovers following a gluten-free diet. The presence of circulating antiendomysial antibodies as well as their disappearance after a gluten-free diet supports the diagnosis. It has also been demonstrated that antiendomysial antibodies are detectable in supernatants of cultured intestinal biopsies from patients with coeliac disease. The objective of this study was to compare the histology and antiendomysial antibodies in culture supernatants of intestinal biopsies to validate the in vitro organ culture system as a future diagnostic tool for coeliac disease. MATERIAL AND METHODS Seventy-five antiendomysial serum-positive patients on a gluten-containing diet were evaluated. Patients underwent endoscopy with 5 biopsy fragments: 3 for histology, 1 cultured with and the other without gliadin-peptide activator. Antiendomysial antibodies were evaluated in all culture supernatants. RESULTS Sixty-eight patients had evidence of villous atrophy, while 73 out of 75 were positive to the organ culture system. The agreement rate between organ culture and histology results was 94%. CONCLUSIONS As all the centres participating in the study obtained good agreement between organ culture and histology results, the new system could be considered a reliable tool for the diagnosis of coeliac disease. Nevertheless, it is possible to highlight cases with an organ culture-positive and -negative histology. This feature could be of considerable interest because, as the sensitivity of organ culture seems to be greater than the initial histology, the new system might be useful in uncertain cases where the risk of missing the diagnosis of coeliac disease is high.

Celiac disease diagnosis in misdiagnosed children

Antiendomysial antibodies (EMA) are today considered the most sensitive and specific serological marker of celiac disease (CD). The aim of the present study was to assess the occurrence of EMA of IgG isotype in EMA IgA negative children with clinical suspicion of malabsorption and their relationship with CD. Serum EMA IgG1 determination was performed on 30 EMA IgA negative children with clinical suspicion of CD. Total serum IgA levels were further investigated. Sixty children with gastroenterological diseases other than CD were used as control disease patients and 63 healthy children were evaluated as the control group. Eighteen out of 30 children in the study showed EMA IgG1 positivity in sera and a villous height/crypt depth ratio ,3:1 as index of intestinal atrophy. It is noticeable that a selective IgA deficiency was present in only 9 of 18 EMA IgG1 positive children. In addition, clinical symptoms, EMA IgG1, and mucosal atrophy disappeared after 8–10 mo on a gluten-free diet. Neither EMA IgA nor EMA IgG1 were detected in the children in the control groups. The other 12 children in study group showed no histologic abnormalities and were EMA IgG1 negative. In this study, we reveal a group of EMA IgG1 CD children without IgA deficiency. The diagnosis was based on the presence of gluten-dependent typical serological and histologic features of CD. Our data suggest that EMA IgG1 determination could be a new tool in the diagnostic workup of CD, useful in avoiding possible misdiagnosis. (Pediatr Res 48: 590–592, 2000)