Risk of Cross-Contact for Gluten-Free Pizzas in Shared-Production Restaurants in Relation to Oven Cooking Procedures.

To allow celiac patients to have meals out, a growing number of restaurants and pizzas houses that simultaneously provide gluten-free (GF) pizzas and wheat-based (WB) pizzas have recently been opened in Italy. In these restaurants, GF pizzas are prepared with GF raw materials, following procedures that minimize the risk of gluten cross-contact. Here, we evaluate the risk of gluten cross-contact of GF pizzas in relation to the preparation procedures, thus aiming at identifying a safe procedure for cooking GF pizzas. Our results show that, when specific requirements are complied with, the simultaneous cooking of GF and WB pizzas is a procedure as safe as having an oven dedicated to GF pizzas or the alternate cooking of GF and WB pizzas in the same oven.

Gliadin-dependent cytokine production in a bidimensional cellular model of celiac intestinal mucosa.

The downstream cascade of the inflammatory response to gliadin in celiac intestinal mucosa encompasses the early activation of the innate immunity that triggers the adaptive response. Therefore, the in vitro study of the pathogenic mechanism of celiac disease (CD) on enterocytes alone or mucosal T lymphocytes alone does not fully consider all the aspects of gliadin-dependent inflammation. Although the in vitro culture of specimens of intestinal mucosa obtained from celiac patients is the gold standard for the study of CD, this technique presents several technical challenges and the bioptic specimens are not easily available. So, in this paper, we described the gliadin-dependent cytokine production in a bidimensional cellular system, which is able to mimic both the innate and the adaptive steps of the mucosal immune response of CD. In the upper compartment, the intestinal epithelial cells are grown on a filter, and in the lower compartment, the mononuclear cells isolated from peripheral blood of celiac patients are cultured. Cells were apically exposed to the toxic gliadin peptide p31-43 for 3 h and then with the immunodominant gliadin fragment pα-9 for 21 h. The incubation with gliadin peptides resulted in increased levels of IL-15, INF-γ, IL-6, tumor necrosis factor (TNF)-α, IL-1ß, and CCL 2, 3 and 4 in the basal supernatants, with respect to cells exposed to medium alone. The p31-43-driven epithelial priming of mucosal response consists of transglutaminase (TG2)-mediated deamidation of the immunostimulatory gliadin peptides, as demonstrated by the inhibition of pα-9 activity, when the system is exposed to blocking anti-TG2 antibody.