e278 Abstracts / Digestive and Liver Disease 45 (2013) e263–e311 CO32 NATURAL HISTORY OF POTENTIAL CELIAC DISEASE: MULTICENTER STUDY M. Proto 1 , P. Alvisi 2 , C. Barbera 3 , S. Cardile 4 , C. Romano 4 , R. Cozzali 5 , G. Castellucci 5 , C. Colombo 6 , G. Guariso 7 , M. Pescarin 7 , P. Kosova 8 , L. Giancotti 9 , L. Pensabene 9 , M.R. D’Altilia 10 , R. Auricchio 1 1 Department of Pediatrics, AOU Policlinico “Federico II”, Naples, Italy 2 Department of Pediatrics, Maggiore Hospital, Bologna, Italy 3 Department of Pediatrics, University of Turin Alma Universitas Turinensis, Turin, Italy 4 Department of Pediatrics, AOU Policlinico “G.Martino”, Messina, Italy 5 Department of Pediatrics and Neonatology, San Giovanni Battista Hospital, Foligno, Italy 6 Department of Pediatrics, IRCCS Ospedale Maggiore Policlinico, Milan, Italy 7 Department of Pediatrics “Salus Pueri”, University of Padova, Padova, Italy 8 Department of Pediatrics, PO S.Paolo, Naples, Italy 9 Department of Pediatrics, “Magna Graecia” University, Catanzaro, Italy 10 Department of Pediatrics, IRCCS S.Giovanni Rotondo, S.Giovanni Rotondo, Italy Background: Potential celiac disease (CD) is a condition char- acterized by positivity of CD serology (anti-endomysial antibodies EMA and anti-transglutaminases IgA anti-TG2) in the absence of intestinal mucosa damage. Aim of the study vas to verify the clinical, serological and genetic characteristics of potential CD population in the nationwide territory and particularly what is the nutritional management of these patients in different CD centers. Methods: The study included 300 children with potential CD fulfilling the inclusion criteria from 10 different Italian CD centers (with median follow-up of 2 years). During the follow-up auxologi- cal parameters, presence of symptoms, antibody titers, diet (with or without gluten) were evaluated periodically. Every 2 years a biopsy was performed to check the status of the duodenal mucosa. Data were collected using a specific form. Results: At the time of diagnosis, 33% of patients were asymp- tomatic (15.3% were first degree of CD patients). In the symptomatic group (67%) the most frequent symptoms were abdominal pain (18.3%) and weight loss (16.3%). The mean values of anti-TG2 was 37.6 U/ml. Duodenal biopsies at first evaluation showed normal mucosal architecture in 52.5% and evidence of inflammatory infil- tration in 47.2%. At the end of follow-up (range 2–5 years), 73% was still on a diet containing gluten, while 17% started a gluten-free diet for symptoms and 8% for villous atrophy development. Conclusion: This observational study has confirmed that poten- tial celiac disease remains quite a problem common to all CD Italian Centers. There were no substantial differences in the characteris- tics and management of patients from different centers. Gluten-free diet is prescribed only in 25% of patients. CO33 INTESTINAL ANTI-TISSUE TRANSGLUTAMINASE IGA DEPOSITS IN CHILDREN WITH CELIAC DISEASE: SIGNIFICANCE AND CORRELATION WITH INTESTINAL DAMAGE M. Rossi 1 , S. Gatti 1 , V. Romagnoli 1 , S. Alfonsi 2 , S. Biagetti 2 , T. Biscotti 2 , V. Albano 1 , A. Mandolesi 2 , I. Bearzi 2 , C. Catassi 1 1 Pediatrics, University Politecnica delle Marche, Ancona, Italy 2 Pathology, University Politecnica delle Marche, Ancona, Italy Background: Anti-tissue transglutaminase IgA (TG2 IgA) are produced and secreted in the intestinal mucosa of celiac disease (CD) patients and deposited on extracellular TG2 of the intesti- nal mucosa, where they settle even before blood appearance. CD patients present mucosal deposits specific for TG2 below the villous and the crypt basement membrane and around mucosal vessels. Without villous atrophy, anti-TG2 IgA deposits have a high predic- tive value of evolution in celiac disease. Aim: To establish the diagnostic value of intestinal deposits of anti-TG2 IgA in CD patients, to assess the degree of concordance between intestinal deposits of anti-TG2 IgA and serum anti-TG2 IgA, to characterize the different pattern of intensity, localization and distribution of anti-TG2IgA mucosal deposits. Materials and methods: This study involved 91 children prospectively recruited from June 2010 to June 2013 in our service, including 71 patients (mean age 8 ys, range 1–17) that underwent small intestinal biopsy for suspected CD and 20 children (mean age 8.5 ys, range 1–17) that underwent small intestinal biopsy for other GI diseases (control group). Serum levels of anti-TG2 IgA and total IgA were evaluated in all patients and patients with IgA deficiency were excluded. The study population was divided into 3 groups: group A, 61 untreated CD patients with villous atrophy (Marsh 2–3); group B, 10 patients with high serum levels of anti-TG2 IgA but minimal intestinal lesions (Marsh 0, 1) defined as potential CD and group C, 20 children with non-celiac GI disease and negative for serum anti-TG2 IgA. Biopsies were evaluated for the presence of intestinal deposits of anti-TG2 IgA by double immunofluorescence for their intensity (weak, moderate, strong), distribution (patchy or homogeneous) and localization (below villous and crypt basement membrane and around mucosal vessels). Results: In all patients from group A and B double immuno- fluorescence showed specific anti-TG2 IgA deposits due to the co-localization of IgA with TG2. In group C only 2 subjects pre- sented IgA deposits. Sensitivity and specificity of intestinal TG2 IgA were respectively 100% (95% CI: 94–100%) and 90% (95% CI: 68.2–98.4%) in A and B groups. Positive predictive value was 96.8% and 83.3% respectively in group A and B, negative predictive value was 100% in both groups. We found a statistically significant dif- ference for intensity (weaker in group A, p = 0.08) and distribution (prevalence of patchy pattern in group A and homogeneous in group B p = 0.032) of anti-TG2 IgA mucosal deposits between A and B groups. The prevalent localization (69%) appears below villi and crypts basement membrane and around mucosal vessels. No corre- lation between deposit’s features and serum levels of anti-TG2 was found. Conclusions: These results revealed high diagnostic sensibility of anti-TG2 IgA deposits in paediatric CD. In patients with potential CD the presence of anti-TG2 IgA deposits has an important diagnos- tic value since it reveals the presence of an initial mucosal damage