ELISA based on peptide antigens reproducing cross-reactive viral epitopes to detect antibodies in latent autoimmune diabetes in adults vs. type 1 diabetes
Feliciana Real-Fernández,
Alessandra Gallo,
Francesca Nuti,
Lorenzo Altamore,
Gloria Giovanna Del Vescovo,
Pietro Traldi,
Eugenio Ragazzi,
Paolo Rovero,
Annunziata Lapolla,
Anna Maria Papini
Affiliations
Feliciana Real-Fernández
Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry “Ugo Schiff”, University of Florence, Sesto Fiorentino, Italy
Alessandra Gallo
Diabetology and Dietetics, Department of Medicine (DIMED), University of Padova, Padova, Italy
Francesca Nuti
Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry “Ugo Schiff”, University of Florence, Sesto Fiorentino, Italy
Lorenzo Altamore
Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry “Ugo Schiff”, University of Florence, Sesto Fiorentino, Italy
Gloria Giovanna Del Vescovo
Diabetology and Dietetics, Department of Medicine (DIMED), University of Padova, Padova, Italy
Pietro Traldi
Istituto di Ricerca Pediatrica, Città della Speranza, Padova, Italy
Eugenio Ragazzi
Department of Pharmaceutical and Pharmacological Sciences, School of Medicine and Surgery, University of Padova, Padova, Italy
Paolo Rovero
Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Neurosciences, Psychology, Drug Research and Child Health, Section of Pharmaceutical Sciences and Nutraceutics, University of Florence, Sesto Fiorentino, Italy
Annunziata Lapolla
Diabetology and Dietetics, Department of Medicine (DIMED), University of Padova, Padova, Italy; Corresponding authors.
Anna Maria Papini
Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry “Ugo Schiff”, University of Florence, Sesto Fiorentino, Italy; PeptLab@UCP Platform and CNRS BioCIS, CY Cergy Paris Université, Cergy-Pontoise, France; Corresponding authors.
Diagnosis of Latent Autoimmune Diabetes in Adults (LADA) is based on the adult-age, anti-islet autoantibodies, and temporary insulin-independence. As in Type-1-Diabetes (T1DM), autoimmunity may trigger LADA and enteroviruses-infections can play a role. Anti-human Glutamic-Acid-Decarboxylase (hGAD) autoantibodies are accepted clinical biomarkers, but do not discriminate LADA vs. T1DM. The hypothesis is that protein antigens detecting anti-hGAD antibodies do not expose epitopes specific for different disease forms.We investigated the diagnostic value of autoantibodies in LADA vs. T1DM to peptides of hGAD65/67 isoforms, and Enterovirus-Coxsackie-B4 (CVB4), as antigens sharing the epitope PEVKXK (X: E/T) included in CD8 T-cell CVB4 epitope restricted by diabetes-associated HLA-A2.1. Statistically significant differences of IgM and/or IgG in LADA and T1DM vs. controls were identified. In LADA IgMs to GAD65/67 peptides are diagnostics, IgGs to GAD65/67 peptides correlate with anti-CVB4 peptide antibodies. IgM and/or IgG to all tested peptides can predict LADA, monitoring CVB4 infected patients, improving LADA vs. T1DM stratification. • A customized SP-ELISA based on synthetic peptides Ac-hGAD65(250-273)-NH2 (1), Ac-hGAD67(258-281)-NH2 (2), and Ac-CVB4P2C(28-50)-NH2 (3) is described. • The method was designed to detect specific IgM and/or IgG in LADA, T1DM, vs. controls • Final aim is improvement of LADA vs. T1DM patient stratification.
