S. Vetrano

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.

Antiendomysial antibody detection in fecal supernatants: in vivo proof that small bowel mucosa is the site of antiendomysial antibody production

OBJECTIVES: Serum antiendomysial antibodies (EMAs), highly sensitive and specific serological markers of celiac disease (CD), are detectable in culture media of biopsy samples from CD patients. This finding can be considered an in vitro evidence that intestinal mucosa is a site of EMA production. To confirm this finding, we investigated the presence of EMAs and of anti-tissue transglutaminase (anti-tTG), recently identified as the autoantigen of the EMA, in fecal supernatants of CD patients. METHODS: Twenty-one newly diagnosed CD patients, 10 treated CD patients on a gluten-free diet, and 14 control disease patients on a gluten-containing diet were enrolled. Twenty-four-hour stool collections and fecal supernatants were obtained from all patients in the study. Biopsy cultures were also performed. IgA EMAs were detected in sera, culture media, and fecal supernatants. IgA, IgG, IgM, and IgE anti-gliadin antibodies (AGAs) and IgA anti-tTG antibodies were measured in fecal supernatants. The weights, water content, and pHs of the 24-h stool collections were also measured. RESULTS: In all untreated CD patients EMAs were detectable in sera, culture media, and fecal supernatants. In treated CD patients, EMAs were detected only in culture media after in vitro gliadin challenge. No EMAs were detected in controls. Anti-tTG levels were higher in untreated CD patients than in treated CD patients and controls. IgA AGA levels were higher in untreated CD patients than in treated CD and control patients, whereas IgM AGAs were higher in both untreated and treated CD patients than in controls. No statistically significant differences were observed for IgG and IgE AGAs among the above-mentioned populations. Fecal weights, water content, and pHs were higher in untreated CD than in control patients. CONCLUSIONS: The presence of EMAs in fecal supernatants represents the in vivo proof that intestinal mucosa is a site of EMA production. Furthermore, EMA detection in the stools could be a simple and useful additional tool to clarify diagnosis in the patchy conditions of CD.

Antiendomysial antibody detection in biopsy culture allows avoidance of gluten challenge in celiac children

Objective: Antiendomysial antibody (EMA) production has been induced in vitro by the small bowel mucosa of celiac disease (CD) patients in clinical remission cultured in the presence of gliadin peptides. The aim of the present study was to use this in vitro system to determine whether it could be used to predict the clinical or histologic relapse to gluten challenge in CD children on a gluten-free diet (GFD). Methods: Enrolled were 32 CD children and adolescents on GFD (group 1), and 80 controls (group 2) who underwent in vitro gliadin challenge. Subsequently, 24 group 1 CD children underwent in vivo gluten challenge to confirm the diagnosis. Biopsy cultures, with and without gliadin, morphometric analysis, immunoglobulin (Ig)A and IgG1 EMA detection, both in sera and culture supernatants, were performed. Results: Of the 32 group 1 CD patients, 23 were IgA EMA positive in culture supernatants. The other nine were IgG1 EMA positive. All 24 children who had in vivo gluten challenge showed clinical or histologic relapse. All culture supernatants from disease controls belonging to group 2 were both IgA and IgG1 EMA negative, irrespective of gliadin challenge. Conclusions: Organ culture with in vitro gliadin challenge is able to reproduce the results of in vivo challenge. This system could reduce the need for gluten challenge in celiac children.

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

OBJECTIVEnDiagnosis 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.nnnMATERIAL AND METHODSnSeventy-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.nnnRESULTSnSixty-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%.nnnCONCLUSIONSnAs 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.