ISSN:
1432-0428
Keywords:
Key words Glutamic acid decarboxylase, receiver-operating characteristic plot, diagnostic accuracy, islet cell antibodies, autoimmunity, diabetes mellitus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Insulin-dependent diabetes mellitus (IDDM) is associated with autoreactivity against GAD but the diagnostic sensitivity (positivity in disease) and specificity (negativity in health) of isoform-specific GAD antibodies have yet to be defined in assay systems suitable for screening large number of samples. One set of IDDM patient (n =10) and control (n =50) standard sera were used to develop quantitative antibody assays with in vitro synthesized recombinant 35S-methionine-labelled GAD65 and GAD67, respectively, and protein A-Sepharose to separate free from antibody-bound ligand. Binding levels were not normally distributed (p 〈0.0001) and therefore, the diagnostic accuracy of GAD antibodies was analysed by the ROC plots in population-based, consecutively-diagnosed, recent onset, 0–14 year-old patients (n =105), and matched, healthy control subjects (n =157). The ROC plots showed that the diagnostic sensitivity of GAD65 antibodies was 77 % and the specificity 92 % compared with 8 % and 98 %, respectively for GAD67 antibodies. In the IDDM sera, GAD65 and GAD67 antibodies were concordant in 7 % (6 of 81) and GAD65 antibodies and ICA in 89 % (72 of 81) without a correlation between the autoantibody levels. Autoantibodies to recombinant human islet GAD65 are specific and sensitive markers for childhood IDDM in this immunoassay with in vitro synthesized 35S-methionine-labelled recombinant GAD. [Diabetologia (1994) 37: 344–350]
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00408469
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