Glutamic Acid Decarboxylase Antibody
Ordering Recommendation
Most useful to establish autoimmune etiology in previously diagnosed type 1 diabetes mellitus (DM). Do not use to differentiate type 1 DM from type 2 DM, for most cases.
If pursuing antibody testing to determine autoimmune DM, perform at least two antibody tests. In most cases, use glutamic acid decarboxylase antibody in combination with another antibody test. Other antibody tests include Islet Antigen-2 (IA-2) Autoantibody (3001499), Insulin Antibody (0099228), Islet Cell Cytoplasmic Antibody, IgG (0050138), and Zinc Transporter 8 Antibody (2006196). For analysis in CSF, refer to Glutamic Acid Decarboxylase Antibody, CSF (3002788).
Methodology
Semi-quantitative Enzyme-Linked Immunosorbent Assay
Performed
Sun-Fri
Reported
1-3 days
New York DOH Approval Status
Specimen Required
Serum separator tube.
Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL)
Frozen.
Plasma. Grossly hemolyzed specimens.
Ambient: 24 hours; Refrigerated: 1 week; Frozen: 3 months
Reference Interval
0.0-5.0 IU/mL
Interpretive Data
A value greater than 5.0 IU/mL is considered positive for glutamic acid decarboxylase antibody (GAD Ab).
This assay is intended for the semi-quantitative determination of the GAD Ab in human serum. Results should be interpreted within the context of clinical symptoms.
FDA
Note
Hotline History
CPT Codes
86341
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
2001772 | Glutamic Acid Decarboxylase Antibody | 56540-8 |
Aliases
- 64K Antibody
- Anti-GAD Antibodies
- Anti-Glutamic Acid Decarboxylase Ab
- Beta Cell Antibody
- Beta-Cell Autoantibody to GAD 65
- GAD Antibody
- GAD-65
- GAD65
- GAD65 Antibody Assay
- Glutamate Decarboxylase Antibodies
- Pancreatic Islet Cell Ab