THE IMMUNOLOGICAL RESPONSE TO GLIADIN IN COELIAC DISEASE SEEKS NOT TO BE OF PRIMARY PATHOGENETIC IMPORTANCE

Abstract

Patients with untreated coeliac disease have circulating antibodies against gliadin. We have previously demonstrated that the gliadin-antibody pattern is dominated by reactivity against a few polypeptides, tentatively identified as gamma-gliadins by their migration in electrophoresis. A varying degree of reactivity to alfa- and beta-gliadin was detected, but the sera did not react with glutenins. It was accordingly hypothesised that the reaction pattern was due to a specific primary reactivity against some gliadin polypeptides, with a secondary immunization with other polypeptides, initiated by epithelial damage and increased intestinal permeability.Gliadin, digested with pepsin and trypsin (PT-gliadin), has been shown to be toxic. In order to further elucidate the connection between gliadin antigenecity and toxicity, the antibody reactivity in coeliac sera against PT-gliadin was investigated by immunoblotting. The enzymatic digestion of gliadin accomplished low molecular weight polypeptides, which notably did not display antibody reactivity.It is therefore suggested that characteristic gliadin antibody pattern in patients with coeliac disease is not of primary pathogenetic importance, but instead correlated to common HLA-antigens of most of the patients.