title: Detection of specific IgA antibodies against a novel deamidated 8-Mer gliadin peptide in blood plasma samples from celiac patients.
abstract: We studied whether celiac disease (CD) patients produce antibodies against a novel gliadin peptide specifically generated in the duodenum of CD patients by a previously described pattern of CD-specific duodenal proteases. Fingerprinting and ion-trap mass spectrometry of CD-specific duodenal gliadin-degrading protease pattern revealed a new 8-mer gliadin-derived peptide. An ELISA against synthetic deamidated 8-mer peptides (DGP 8-mer) was used to study the presence of IgA anti-DGP 8-mer antibodies in plasma samples from 81 children (31 active CD patients (aCD), 17 CD patients on a gluten-free diet (GFD), 10 healthy controls (C) and 23 patients with other gastrointestinal pathology (GP)) and 101 adults (16 aCD, 12 GFD, 27 C and 46 GP-patients). Deamidation of the 8-mer peptide significantly increased the reactivity of the IgA antibodies from CD patients against the peptide. Significant IgA anti-DGP 8-mer antibodies levels were detected in 93.5% of aCD-, 11.8% of GFD- and 4.3% of GP-patients in children. In adults, antibodies were detected in 81.3% of aCD-patients and 8.3% of GFD-patients while were absent in 100% of C- and GP-patients. Duodenal CD-specific gliadin degrading proteases release an 8-mer gliadin peptide that once deamidated is an antigen for specific IgA antibodies in CD patients which may provide a new accurate diagnostic tool in CD.
authors.affiliation: Mucosal Immunology Laboratory, IBGM, University of Valladolid-Consejo Superior de Investigaciones Científicas, Valladolid, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Vallejo-Diez
authors.forename: David
authors.initials: D
authors.lastname: Bernardo
authors.forename: María de Lourdes
authors.initials: Mde L
authors.lastname: Moreno
authors.forename: Alba
authors.initials: A
authors.lastname: Muñoz-Suano
authors.forename: Luis
authors.initials: L
authors.lastname: Fernández-Salazar
authors.forename: Carmen
authors.initials: C
authors.lastname: Calvo
authors.forename: Carolina
authors.initials: C
authors.lastname: Sousa
authors.forename: José A
authors.initials: JA
authors.lastname: Garrote
authors.forename: Angel
authors.initials: A
authors.lastname: Cebolla
authors.forename: Eduardo
authors.initials: E
authors.lastname: Arranz
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000918:Antibody Specificity / Q000276:immunology*; D002446:Celiac Disease / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004386:Duodenum / Q000276:immunology / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000276:immunology; D005260:Female; D005903:Gliadin / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology*; D007223:Infant; D008297:Male; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology*; D010447:Peptide Hydrolases / Q000378:metabolism; D059748:Proteolysis
chemical_list: D018984:Epitopes, T-Lymphocyte; D007070:Immunoglobulin A; D010446:Peptide Fragments; D005903:Gliadin; D010447:Peptide Hydrolases