Glutamic Acid Decarboxylase-65 Antibody

Cleveland HeartLab G, Test

NEW YORK DOH APPROVED: YES
CPT Code: 86341
Order Code: C1574
ABN Requirement:  No
Synonyms: GAD-65 Antibodies
Specimen: Serum
Volume: 1.0 mL
Minimum Volume: 0.5 mL
Container: Gel-barrier tube (SST, Tiger Top)

Collection:

Serum:

  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 5 times immediately after draw. DO NOT SHAKE.
  3. Allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.

Transport: Store serum at 2°C to 8°C after collection and ship the same day per packaging instructions provided with the Cleveland HeartLab shipping box.

Stability:

Ambient (15-25°C): 7 days
Refrigerated (2-8°C): 14 days
Frozen (-20°C): 60 days
Deep Frozen (-70°C): 60 days

Causes for Rejection: Specimens other than serum; improper labeling; samples not stored properly; samples older than stability limits

Methodology: Enzyme Linked Immunosorbent Assay (ELISA)

Turn Around Time: 5 to 7 days

Reference Range:

Age IU/mL
All Ages <5

Clinical Significance: Glutamic acid decarboxylase-65 (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).

Limitations: GAD-65 antibodies are detected in 20% of diabetic twins who remain disease-free for long periods of time and in 8% of healthy individuals.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.