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Test Code GADABM Glutamic Acid Decarboxylase (GAD65) Antibody Assay, Serum

Additional Codes

 

MAYO Test ID

GD65S

EPIC Test ID

LAB650

 

Reporting Name

GAD65 Ab Assay, S

Useful For

Assessing susceptibility to autoimmune (type 1, insulin-dependent) diabetes mellitus and related endocrine disorders (eg, thyroiditis and pernicious anemia). Titers generally ≤0.02 nmol/L. A second islet cell antibody (IA-2) is more predictive for development of type 1 diabetes, but less frequent than glutamic acid decarboxylase (GAD65) antibody amongst diabetic patients. Insulin autoantibodies also serve as a marker of susceptibility to type 1 diabetes.

 

Distinguishing between patients with type 1 and type 2 diabetes. Assays for IA-2, insulin, gastric parietal cell, thyroglobulin, and thyroid peroxidase antibodies, complement GAD65 antibody in this context; titers generally ≤0.02 nmol/L.

 

Confirming a diagnosis of stiff-man syndrome, autoimmune encephalitis, cerebellitis, brain stem encephalitis, myelitis; titers generally ≥0.03 nmol/L

 

Confirming susceptibility to organ-specific neurological disorders (eg, myasthenia gravis, Lambert-Eaton syndrome); titers generally ≤0.02 nmol/L

Method Name

Radioimmunoassay (RIA)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 1 mL


Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  72 hours

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross reject

Other

NA

Reference Values

≤0.02 nmol/L

Reference values apply to all ages.

Day(s) and Time(s) Performed

Sunday through Thursday; 10 p.m.

CPT Code Information

86341

LOINC Code Information

Test ID Test Order Name Order LOINC Value
GD65S GAD65 Ab Assay, S 30347-9

 

Result ID Test Result Name Result LOINC Value
81596 GAD65 Ab Assay, S 30347-9

Analytic Time

2 days/negative 3 days/positive

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.