Evaluation of a novel radioimmunoassay using125I-labelled human recombinant GAD65 for the determination of glutamic acid decarboxylase (GAD65) autoantibodies

2000 ◽  
Vol 30 (1) ◽  
pp. 21-26 ◽  
Author(s):  
S. M. Marcovina ◽  
M. Landin-Olsson ◽  
A. Essen-Möller ◽  
J. P. Palmer ◽  
Å. Lernmark
Keyword(s):  
Glutamic Acid ◽  
Glutamic Acid Decarboxylase ◽  
Acid Decarboxylase ◽  
Gad65 Autoantibodies

Diagnostic sensitivity of immunodominant epitopes of glutamic acid decarboxylase (GAD65) autoantibodies in childhood IDDM

Diabetologia ◽  
1996 ◽  
Vol 39 (9) ◽  
pp. 1091-1098 ◽  
Author(s):  
A. Falorni ◽  
M. Ackefors ◽  
C. Carlberg ◽  
T. Daniels ◽  
B. Persson ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Glutamic Acid Decarboxylase ◽  
Diagnostic Sensitivity ◽  
Acid Decarboxylase ◽  
Gad65 Autoantibodies ◽  
Childhood Iddm ◽  
Immunodominant Epitopes

scholarly journals Evaluation of Two Nonisotopic Immunoassays for Determination of Glutamic Acid Decarboxylase and Tyrosine Phosphatase Autoantibodies in Serum

2004 ◽  
Vol 50 (8) ◽  
pp. 1378-1382 ◽  
Author(s):  
Xavier Palomer ◽  
Dídac Mauricio ◽  
José Rodríguez-Espinosa ◽  
Edgar Zapico ◽  
Carme Mayoral ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Glutamic Acid Decarboxylase ◽  
Clinical Laboratory ◽  
Autoimmune Diabetes ◽  
Tyrosine Phosphatase ◽  
Acid Decarboxylase ◽  
Time Resolved ◽  
Radiobinding Assay

Abstract Background: Autoantibodies for the 65-kDa form of glutamic acid decarboxylase (GAD65) and protein tyrosine phosphatase-like protein (IA-2) are measured for risk prediction and diagnosis of autoimmune diabetes mellitus. There is a lack of adequate nonisotopic alternatives to the most widely used method for both autoantibodies, which is a radiobinding assay (RBA). Methods: We compared two commercially available immunoassays, an ELISA and a time-resolved immunofluorometric assay (TR-IFMA), with RBA. Results: We found excellent agreement between the RBA and ELISA for measurement of GAD65 autoantibodies (GADAs); they showed comparable analytical precision in the cutoff range and achieved similar diagnostic specificity. The ELISA identified more GADA-positive individuals among patients with new-onset type 1 diabetes than did the RBA [89% (95% confidence interval, 78–95%), vs 71% (58–82%); P <0.03]. For IA-2 autoantibodies (IA-2As), only the TR-IFMA achieved analytical performance and diagnostic accuracy comparable to that of the RBA. These results with the GADA ELISA and IA-2A TR-IFMA were consistent with those obtained blindly in the Diabetes Antibody Standardization Program 2003. The performance of the GADA TR-IFMA and IA-2A ELISA was unsatisfactory, and these tests were not subjected to clinical evaluation. Conclusions: The GADA ELISA and IA-2A TR-IFMA behave comparably with RBA and are thus suitable for use in the clinical laboratory.

scholarly journals Characterization of the humoral immune response to glutamic acid decarboxylase in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) and/or type 1 diabetes

2005 ◽  
Vol 153 (6) ◽  
pp. 901-906 ◽  
Author(s):  
Matti S Ronkainen ◽  
Taina Härkönen ◽  
Jaakko Perheentupa ◽  
Mikael Knip
Keyword(s):  
Immune Response ◽  
Type 1 Diabetes ◽  
Glutamic Acid ◽  
Glutamic Acid Decarboxylase ◽  
Humoral Immune Response ◽  
Acid Decarboxylase ◽  
Humoral Immune ◽  
Gad65 Autoantibodies ◽  
Autoimmune Polyendocrinopathy

Objective: A humoral autoimmune response to glutamic acid decarboxylase (GAD65) is common both in patients with type 1 diabetes and in those with the autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome, while overt type 1 diabetes is relatively rarely diagnosed in APECED patients. The aim of this study was to assess whether this difference in the incidence of type 1 diabetes is associated with variability in the humoral immune response to GAD65, one of the major autoantigens in type 1 diabetes. Methods: Epitope- and isotype-specific GAD65 autoantibodies were analysed in 20 patients with APECED and 20 patients with newly diagnosed type 1 diabetes alone by radiobinding assays. Results: GAD65 autoantibodies targeted the middle and carboxy-terminal regions of GAD65 and occasionally the amino-terminal region in the APECED patients and comprised mainly the IgG1 subclass and less frequently the IgG2 and IgG4 subclasses. The profile of epitope- and isotype-specific GAD65 autoantibodies was similar in type 1 diabetes and APECED, except that IgG2 subclass antibodies were observed more often and at higher levels in the patients with type 1 diabetes alone (P < 0.05). None of the measured parameters separated APECED patients with type 1 diabetes from those without type 1 diabetes. Conclusion: APECED-associated humoral autoimmunity to GAD65 does not differ markedly from that observed in type 1 diabetes; only IgG2-GAD65 antibodies may be more closely associated with the latter entity.

Sign in / Sign up

Export Citation Format

Share Document