Glutamic Acid Decarboxylase Autoantibody (GADA) ELISA Kit
Kit Size: 96 wells/Kit
Typical results
(Example only, not for calculation of actual results)
Calibrator* | Concentration (IU/ml) | OD450 | OD405 |
1 | 2000 | 5.160 | 1.551 |
2 | 250 | 4.345 | 1.306 |
3 | 120 | 3.732 | 1.0865 |
4 | 35 | 1.445 | 0.439 |
5 | 18 | 0.794 | 0.2565 |
6 | 10 | 0.4785 | 0.168 |
7 | 5 | 0.276 | 0.1125 |
Negative Control | 0 | 0.096 | 0.0655 |
Positive Control | 15.18 | 0.746 | 0.235 |
*Calibrator standardised against NIBSC 97/550.
Cut-off Value
Cut off | IU/ml |
Negative | < 5 IU/ml |
Positive | ≧ 5 IU/ml |
*This cut off has been validated at ImmunoDiagnostics. However, we recommend each laboratory establish its own reference ranges of GADA levels to distinguish healthy and pathological subjects, as well as include its own internal control samples in the assay.
INTRODUCTION
Glutamic acid decarboxylase autoantibodies (GADA) are found in 70% to 80% of individuals with new-onset type 1 diabetes, making it the most frequent autoantibody in autoimmune diabetes.
GADA can be detected in serum for many years post diagnosis, and high concentrations of GADA have been considered as a marker of faster β-cell exhaustion in these patients.
Furthermore, GADA in non-diabetic individuals predicts the later development of type 1 diabetes1.
Besides autoimmune diabetes, GADA also exists in Stiff Man Syndrome, autoimmune poly-endocrinopathies, and some of Grave’s Disease patients2.
ASSAY CHARACTERISTICS
Clinical Evaluation
Sensitivity
92.5% (n=80)
Specificity
95% (n=150)
Inter-Assay Precision
Sample
IU/ml (n=20)
CV
1
120
5.75%
2
18
6.66%
3
5
5.26%
Intra-Assay Precision
Sample
IU/ml (n=20)
CV
1
120
6.61%
2
18
4.63%
3
5
5.65%
Sample Type: SerumStorage : 4°C
References:
1.Liu B, et al. Past, present and future of latent autoimmune diabetes in adults. Diabetes Metab Res Rev. 2019 Jul 18:e3205.
2.Björk E, et al. GAD autoantibodies in IDDM, stiff-man syndrome, and autoimmune polyendocrine syndrome type I recognize different epitopes. Diabetes. 1994 Jan;43(1):161-5.
DATA SHEET