title: Bridging-type enzyme-linked immunoassay for zinc transporter 8 autoantibody measurements in adult patients with diabetes mellitus.
abstract: OBJECTIVE
  A bridging-type ELISA for measuring autoantibodies to zinc transporter 8 (ZnT8A) was assessed using samples from different forms of diabetes mellitus.
  
  
  METHODS
  ZnT8A were measured using an ELISA in patients with type 1 diabetes mellitus (T1DM; n=94), latent autoimmune diabetes of adulthood (LADA; n=51), type 2 diabetes mellitus (T2DM; n=59) and healthy blood donors (HBD; n=200). ZnT8A in ELISA and immunoprecipitation assays (IPA) using ZnT8 dimer (W325/R325) and monomers (W325, R325 and Q325) were compared.
  
  
  RESULTS
  Inter- and intra-assay coefficients of variation (CV) were 7.1% and 1.7%, respectively (medium ZnT8A) and 8.5% and 2.7%, respectively (high ZnT8A). In the ELISA 51/94 (54.3%) T1DM, 16/51 (31.4%) LADA and 1/59 (1.7%) T2DM sera were ZnT8A positive. ROC analysis of T1DM and HBD for the ELISA showed 54% sensitivity and 99% specificity (cutoff 15u/mL) and AUC 0.80 (95% CI, 0.74-0.86). ELISA and IPA measurements were in very good agreement (r=0.856, k=0.889, n=204). Measurement of ZnT8A in addition to autoantibodies for GAD, IA-2 and insulin increased antibody positivity in T1DM by 4.3%, from 80.9% to 85.1%.
  
  
  CONCLUSIONS
  The bridging-type ELISA is a convenient and reproducible method for determination of ZnT8A in serum. Measurement of ZnT8A increased autoantibody positivity in adult T1DM.
authors.affiliation: Diabetes Research Group, Institute of Life Sciences, Swansea University, Swansea SA2 8PP, UK. Electronic address: G.J.Dunseath@swansea.ac.uk.
authors.forename: Gareth
authors.initials: G
authors.lastname: Dunseath
authors.affiliation: FIRS Laboratories, RSR Ltd, Cardiff CF14 5DU, UK.
authors.forename: Rossitza
authors.initials: R
authors.lastname: Ananieva-Jordanova
authors.affiliation: FIRS Laboratories, RSR Ltd, Cardiff CF14 5DU, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Coles
authors.affiliation: FIRS Laboratories, RSR Ltd, Cardiff CF14 5DU, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Powell
authors.affiliation: FIRS Laboratories, RSR Ltd, Cardiff CF14 5DU, UK.
authors.forename: Marie
authors.initials: M
authors.lastname: Amoroso
authors.affiliation: FIRS Laboratories, RSR Ltd, Cardiff CF14 5DU, UK.
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Furmaniak
authors.affiliation: FIRS Laboratories, RSR Ltd, Cardiff CF14 5DU, UK.
authors.forename: Bernard Rees
authors.initials: BR
authors.lastname: Smith
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University, Cardiff CF14 4YU, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Dayan
authors.affiliation: Diabetes Research Group, Institute of Life Sciences, Swansea University, Swansea SA2 8PP, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Luzio
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology*; D016022:Case-Control Studies; D027682:Cation Transport Proteins / Q000737:chemistry / Q000276:immunology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000276:immunology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology; D006801:Humans; D007328:Insulin / Q000276:immunology; D008297:Male; D008875:Middle Aged; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D055815:Young Adult; D000075703:Zinc Transporter 8
chemical_list: D001323:Autoantibodies; D027682:Cation Transport Proteins; D007328:Insulin; C492522:SLC30A8 protein, human; D000075703:Zinc Transporter 8; D005968:Glutamate Decarboxylase
keywords: Autoantibody; ELISA; Type 1 diabetes; ZnT8A