title: Comparison of measurements of autoantibodies to glutamic acid decarboxylase and islet antigen-2 in whole blood eluates from dried blood spots using the RSR-enzyme linked immunosorbent assay kits and in-house radioimmunoassays.
abstract: To evaluate the performance of dried blood spots (DBSs) with subsequent analyses of glutamic acid decarboxylase (GADA) and islet antigen-2 (IA-2A) with the RSR-ELISAs, we selected 80 children newly diagnosed with type 1 diabetes and 120 healthy women. DBSs from patients and controls were used for RSR-ELISAs while patients samples were analysed also with in-house RIAs. The RSR-ELISA-GADA performed well with a specificity of 100%, albeit sensitivity (46%) was lower compared to in RIA (56%; P = .008). No prozone effect was observed after dilution of discrepant samples. RSR-ELISA-IA-2A achieved specificity of 69% and sensitivity was lower (59%) compared with RIA (66%; P < .001). Negative or low positive patients and control samples in the RSR-ELISA-IA-2A increased after dilution. Eluates from DBS can readily be used to analyse GADA with the RSR-ELISA, even if low levels of autoantibodies were not detected. Some factor could disturb RSR-ELISA-IA-2A analyses.
authors.affiliation: Unit for Diabetes and Celiac Disease, Department of Clinical Sciences, Lund University, Wallenberg Laboratory, Entrance 46, University Hospital MAS, 205 02 Malmö, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Persson
authors.forename: Charlotte
authors.initials: C
authors.lastname: Becker
authors.forename: Ida
authors.initials: I
authors.lastname: Hansson
authors.forename: Anita
authors.initials: A
authors.lastname: Nilsson
authors.forename: Carina
authors.initials: C
authors.lastname: Törn
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D008297:Male; D010209:Paper; D011786:Quality Control; D011863:Radioimmunoassay; D011933:Reagent Kits, Diagnostic; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8 / Q000276:immunology*; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D001323:Autoantibodies; D011933:Reagent Kits, Diagnostic; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8; D005968:Glutamate Decarboxylase