Sign in →

Epic Code LAB1232002 Glutamic Acid Decarboxylase (GAD65) Antibody Assay, Serum

Test Name Alias

GAD Antibody, GAD65, stiff-man syndrome | LAB650 | GAD65 | Quest: 34878

Interface Order Alias

1232002

Clinical Information

Glutamic Acid Decarboxylase-65 Antibody - Glutamic acid decarboxylase (GAD-65) antibody is useful to diagnose insulin dependent diabetes mellitus [Type I diabetes (autoimmune-mediated diabetes)] to assess risk for development of Type I diabetes, to predict onset of Type I diabetes, and risk of development of related endocrine disorders, e.g., thyroiditis. Before clinical onset, Type I diabetes is characterized by lymphocytic infiltration of the islet cells, and by circulating autoantibodies against a variety of islet cell antigens, including GAD-65, IA-2 (a tyrosine phosphatase-like protein), and insulin (IAA).

Specimen Requirements

Specimen Collection Criteria

Collect (preferred specimen):  One Gold-top SST tube.
Also acceptable:  One plain Red-top tube.

 

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to plastic transport tube and maintain at room temperature (20-26°C or 68-78.8°F) prior to transport.

 

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to plastic transport tube and maintain at room temperature (20-26°C or 68-78.8°F) prior to transport.

Specimen Transport Temperature

Transport: 1.0 mL serum, room temperature (20-26°C or 68-78.8°F).. (Minimum: 0.5 mL)

Rejection Criteria

  • Grossly hemolyzed specimens.
  • Grossly icteric specimens.
  • Grossly lipemic specimens.
  • Specimens not collected and processed as indicated.

Specimen Stability

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 7 days
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 60 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Test Frequency

Performed: Sunday – Friday.
Results available in 3-5 days.

Reference Range

<5 IU/mL

Performing Department

Send Outs

Performing Department Laboratory Location

Sent to Quest Diagnostics- Wood Dale, IL

Methodology

Enzyme Linked Immunosorbent Assay (ELISA)

CPT

86341

LOINC

56540-8

Reviewed Date

11/2/2025

Orderable Regions

Send Outs