Coeliac disease and gluten sensitivity.

Coeliac disease (CD) is a systemic immune-mediated disorder elicited by gluten in genetically susceptible individuals. The common factor for all patients with CD is the presence of a variable combination of gluten-dependent clinical manifestations, specific autoantibodies (anti-tissue transglutaminase/anti-endomysium), HLA-DQ2 and/or DQ8 haplotypes and different degrees of enteropathy. Recently, gluten sensitivity has received much interest, although the limits and possible overlap between gluten sensitivity and CD remain poorly defined. At present, a number of morphological, functional and immunological disorders that are lacking one or more of the key CD criteria (enteropathy, associated HLA haplotypes and presence of anti-transglutaminase two antibodies) but respond to gluten exclusion are included under the umbrella of gluten sensitivity. The possible immunological mechanisms underlying these conditions are discussed. Emphasis is given to specific autoantibodies as markers of the coeliac spectrum and to the hypothesis that innate epithelial stress can exist independently from adaptive intestinal immunity in gluten sensitivity.