Glutamic Acid Decarboxylase Autoantibodies

Overview

  • EPIC Code:
  • LAB650
  • Soft Test Code:
  • GLUT1
  • Send Out Test Code:
  • 34878
Alternate Names
  • Anti-GAD
  • GAD
  • GAD-65
  • Glutamic Acid Decarboxylase Autoabs
  • Glutamic Acid Decarboxylase-65 Ab
  • Glutamic Acid Decarboxylase-65 Antibody
Clinical Significance

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 Collection & Preparation

Specimen Requirements

1.0 mL Serum from a Red Top Tube in a Plastic Vial


Transport And Storage

7 days Ambient (Transport)
14 days Refrigerated
60 days Frozen


Collection Instructions

 


Minimum Volume

0.5 mL Serum


Neonatal Volume

Clinical Interpretation

Reference Range:

<5 IU/mL


Test Comments:

 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.


Methodology:
  • Enzyme Linked Immunosorbent Immunoassay (ELISA)
Clinical Significance

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).


Production Schedule

Sites Performed
  • Quest - Chantilly
Days Performed
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Departments
  • Sendouts - Clinical
Turn Around Time

3 to 5 days


Coding & Compliance

CDM

00918804


CPT Coding

86341