Higher constitutive IL15R alpha expression and lower IL-15 response threshold in coeliac disease patients

Celiac disease: Alternatives to a gluten free diet

Celiac disease is a chronic inflammatory disorder of the small intestine caused by the ingestion of gluten or related rye and barley proteins. At present, the only available treatment is a strict gluten-exclusion diet. However, recent understanding of the molecular basis for this disorder has improved and enabled the identification of targets for new therapies. This article aims to critically summarize these recent studies.

Celiac disease: from pathogenesis to novel therapies

Celiac disease has become one of the best-understood HLA-linked disorders. Although it shares many immunologic features with inflammatory bowel disease, celiac disease is uniquely characterized by (1) a defined trigger (gluten proteins from wheat and related cereals), (2) the necessary presence of HLA-DQ2 or HLA-DQ8, and (3) the generation of circulating autoantibodies to the enzyme tissue transglutaminase (TG2). TG2 deamidates certain gluten peptides, increasing their affinity to HLA-DQ2 or HLA-DQ8. This generates a more vigorous CD4(+) T-helper 1 T-cell activation, which can result in intestinal mucosal inflammation, malabsorption, and numerous secondary symptoms and autoimmune diseases. Moreover, gluten elicits innate immune responses that act in concert with the adaptive immunity. Exclusion of gluten from the diet reverses many disease manifestations but is usually not or less efficient in patients with refractory celiac disease or associated autoimmune diseases. Based on the advanced understanding of the pathogenesis of celiac disease, targeted nondietary therapies have been devised, and some of these are already in phase 1 or 2 clinical trials. Examples are modified flours that have been depleted of immunogenic gluten epitopes, degradation of immunodominant gliadin peptides that resist intestinal proteases by exogenous endopeptidases, decrease of intestinal permeability by blockage of the epithelial ZOT receptor, inhibition of intestinal TG2 activity by transglutaminase inhibitors, inhibition of gluten peptide presentation by HLA-DQ2 antagonists, modulation or inhibition of proinflammatory cytokines, and induction of oral tolerance to gluten. These and other experimental therapies will be discussed critically.

Genetics and pathogenesis of coeliac disease

Coeliac disease is a common complex disease caused by a dietary intolerance to wheat gluten. Susceptibility is determined by both environmental and genetic factors. Coeliac disease results from complex interactions between the innate immune system, an adaptive T and B cell response and the mucosal barrier where inflammation is ultimately manifested. Genetic variants within the HLA region are well established, while variants outside of the HLA region have recently been identified. These variants are beginning to enhance our understanding of the immunology of the condition. This review focuses on the immunological pathogenesis of coeliac disease with special reference to the influence of genetic susceptibility on disease development.