Search our extensive Laboratory Test Directory to find test codes, ordering recommendations, specimen stability information, Test Fact Sheets, and more.
Recommendations when to order or not order the test. May include related or preferred tests.
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).
New York DOH Approval Status
Indicates whether a test has been approved by the New York State Department of Health.
This test is New York state approved.
Specimen Required
Patient PreparationInstructions patient must follow before/during specimen collection.
CollectSpecimen type to collect. May include collection media, tubes, kits, etc.
Serum separator tube.
Specimen PreparationInstructions for specimen prep before/after collection and prior to transport.
Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL)
Storage/Transport TemperaturePreferred temperatures for storage prior to and during shipping to ARUP. See Stability for additional info.
Frozen.
Unacceptable ConditionsCommon conditions under which a specimen will be rejected.
Plasma. Grossly hemolyzed specimens.
RemarksAdditional specimen collection, transport, or test submission information.
StabilityAcceptable times/temperatures for specimens. Times include storage and transport time to ARUP.
Expected turnaround time for a result, beginning when ARUP has received the specimen.
1-3 days
Reference Interval
Normal range/expected value(s) for a specific disease state. May also include abnormal ranges.
0.0-5.0 IU/mL
Interpretive Data
May include disease information, patient result explanation, recommendations, or details of testing.
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.
Compliance Category
FDA
Note
Additional information related to the test.
Hotline History
N/A
CPT Codes
The American Medical Association Current Procedural Terminology (CPT) codes published in ARUP's Laboratory Test Directory are provided for informational purposes only. The codes reflect our interpretation of CPT coding requirements based upon AMA guidelines published annually. CPT codes are provided only as guidance to assist clients with billing. ARUP strongly recommends that clients confirm CPT codes with their Medicare administrative contractor, as requirements may differ. CPT coding is the sole responsibility of the billing party. ARUP Laboratories assumes no responsibility for billing errors due to reliance on the CPT codes published.
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
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