A simple and rapid microSepharose assay for GAD65 and ICA512 autoantibodies in diabetes. Diabetes Incidence Study in Sweden (DISS).
GAD65Ab and ICA512Ab are strongly associated with insulin-dependent (Type 1) diabetes mellitus. A novel, simple radio-antigen binding assay with microSepharose conjugated with monoclonal antibodies specific for human immunoglobulin light chains was developed to provide diagnostic sensitivity and specificity of GAD65Ab and ICA512Ab for Type 1 diabetes. The Receiver Operating Characteristic (ROC) curve was used to determine the upper level of Normal in 583 new onset Type 1 diabetic patients and in 829 matched controls. The sensitivity of GAD65Ab and ICA512Ab was 66% (384/583) and 41% (211/520), respectively, and the diagnostic specificity was 96% for both autoantibodies. Levels, but not frequency, of GAD65Ab were higher among female Type 1 diabetes patients, whereas ICA512Ab levels did not differ between males and females. Positivity for GAD65Ab. ICA512Ab or both showed a sensitivity of 74% and a specificity of 92% for Type 1 diabetes. This simple, one-step centrifugation, high-capacity radio-antigen binding assay has a high precision and reproducibility to accurately detect both GAD65Ab and ICA512Ab. This assay should also prove useful in other autoantibody assays against conformation-sensitive autoantigens.
Department of Medicine, University of Washington, Seattle 98195-7710, USA. dschranz@u.washington.edu
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DB
Schranz
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L
Bekris
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M
Landin-Olsson
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C
Törn
A
A
Niläng
A
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Toll
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H
Grönlund
B
B
Toivola
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Lernmark
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000276:immunology*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000276:immunology*; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000276:immunology*; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8; D012680:Sensitivity and Specificity; D012685:Sepharose; D012737:Sex Factors; D013205:Staphylococcal Protein A; D013997:Time Factors
D001323:Autoantibodies; D001324:Autoantigens; D008565:Membrane Proteins; D013205:Staphylococcal Protein A; D012685:Sepharose; C516862:PTPRN protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8; D005968:Glutamate Decarboxylase