Troncone, Riccardo

The process of transition from childhood to adulthood is characterised by physical, mental and psychosocial development. Data on the transition and transfer of care in adolescents/young adults with coeliac disease (CD) are scarce. In this paper, 17 physicians from 10 countries (Sweden, Italy, the USA, Germany, Norway, the Netherlands, Australia, Britain, Israel and Denmark) and two representatives from patient organisations (Association of European Coeliac Societies and the US Celiac Disease Foundation) examined the literature on transition from childhood to adulthood in CD. Medline (Ovid) and EMBASE were searched between 1900 and September 2015. Evidence in retrieved reports was evaluated using the Grading of Recommendation Assessment, Development and Evaluation method. The current consensus report aims to help healthcare personnel manage CD in the adolescent and young adult and provide optimal care and transition into adult healthcare for patients with this disease. In adolescence, patients with CD should gradually assume exclusive responsibility for their care, although parental support is still important. Dietary adherence and consequences of non-adherence should be discussed during transition. In most adolescents and young adults, routine small intestinal biopsy is not needed to reconfirm a childhood diagnosis of CD based on European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) or North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) criteria, but a biopsy may be considered where paediatric diagnostic criteria have not been fulfilled, such as, in a patient without biopsy at diagnosis, additional serology (endomysium antibody) has not been performed to confirm 10-fold positivity of tissue transglutaminase antibodies or when a no biopsy strategy has been adopted in an asymptomatic child.

Celiac disease (CD) is an enteropathy caused by the ingestion of wheat gluten in genetically susceptible individuals. A complete understanding of the pathogenic mechanisms in CD has been hindered because of the lack of adequate in vivo models. In the present study, we explored the events after the intragastric administration of gliadin and of the albumin/globulin fraction from wheat in human leukocyte antigen-DQ8 transgenic mice (DQ8 mice) treated with indomethacin, an inhibitor of cyclooxygenases (COXs). After 10 days of treatment, mice showed a significant reduction of villus height, increased crypt depth, increased number of lamina propria-activated macrophages, and high basal interferon-γ secretion in mesenteric lymph nodes, all of which were specifically related to gliadin intake, whereas the albumin/globulin fraction of wheat was unable to induce similar changes. Cotreatment with NS-398, a specific inhibitor of COX-2, also induced the intestinal lesion. Enteropathy onset was further characterized by high levels of oxidative stress markers, similar to CD. Biochemical assessment of the small intestine revealed the specific activation of matrix metalloproteinases 2 and 9, high caspase-3 activity, and a significant increase of tissue transglutaminase protein levels associated with the intestinal lesion. Notably, after 30 days of treatment, enteropathic mice developed serum antibodies toward gliadin (IgA) and tissue transglutaminase (IgG). We concluded that gliadin intake in combination with COX inhibition caused a basal inflammatory status and an oxidative stress condition in the small intestine of DQ8 mice, thus triggering the mucosal lesion and, subsequently, an antigen-specific immunity.

Abstract Celiac disease, triggered by wheat gliadin and related prolamins from barley and rye, is characterized by a strong association with HLA-DQ2 and HLA-DQ8 genes. Gliadin is a mixture of many proteins that makes difficult the identification of major immunodominant epitopes. To address this issue, we expressed in Escherichia coli a recombinant α-gliadin (r-α-gliadin) showing the most conserved sequence among the fraction of α-gliadins. HLA-DQ8 mice, on a gluten-free diet, were intragastrically immunized with a chymotryptic digest of r-α-gliadin along with cholera toxin as adjuvant. Spleen and mesenteric lymph node T cell responses were analyzed for in vitro proliferative assay using a panel of synthetic peptides encompassing the entire sequence of r-α-gliadin. Two immunodominant epitopes corresponding to peptide p13 (aa 120–139) and p23 (aa 220–239) were identified. The response was restricted to DQ and mediated by CD4+ T cells. In vitro tissue transglutaminase deamidation of both peptides did not increase the response; furthermore, tissue transglutaminase catalyzed extensive deamidation in vitro along the entire r-α-gliadin molecule, but failed to elicit new immunogenic determinants. Surprisingly, the analysis of the cytokine profile showed that both deamidated and native peptides induced preferentially IFN-γ secretion, despite the use of cholera toxin, a mucosal adjuvant that normally induces a Th2 response to bystander Ags. Taken together, these data suggest that, in this model of gluten hypersensitivity, deamidation is not a prerequisite for the initiation of gluten responses.