Pediatric Islet Autoantibody Panel (ICA, GADA, IA-2A, IAA and ZnT8A)

Additional Information:


CPT Code(s):

  • ICA: 88346
  • GADA: 86341
  • IA-2A: 86341
  • IAA: 86337
  • ZnT8A: 86341

Specimen Requirements:

Type: Serum
Container/Tube: SST
Sample Volume: 2 mL
Minimum Volume: 1 mL (Repeat testing is not possible with this specimen volume.)
Storage: Centrifuge, separate and transfer the serum to a plastic vial. Ship specimens with a frozen cold pack for overnight delivery.
Stability (collection to time of analysis/testing):

  • Refrigerated: 24 hours
  • Frozen: 1 year


  • Diagnosis of Type 1 Diabetes: The presence of islet cell cytoplasmic autoantibodies (ICA), glutamic acid decarboxylase autoantibodies (GADA), insulinoma-2-associated autoantibodies (IA-2A), insulin autoantibodies (IAA) and/or zinc transporter 8 autoantibodies (ZnT8A) in the serum of patients who have been biochemically diagnosed with diabetes mellitus indicates the presence of autoimmune type 1 diabetes mellitus (aka type 1A diabetes mellitus). It is advised that blood for IAA testing be drawn before insulin therapy is initiated. For the IAA result to be valid, the patient must not be insulin treated for more than one week.
  • Prediction of Type 1 Diabetes: The presence of ICA, GADA, IA-2A, IAA and/or ZnT8A in the serum of an asymptomatic individual places the subject at increased risk for the development of type 1 diabetes mellitus.


Indirect immunofluorescence (ICA), radioimmunoassay (IAA, IA-2A), enzyme-linked immunosorbant assay (ZnT8A, GADA)


7-20 days

Reference Values:


  • Negative (quantitative results reported in JDF units): < 10 JDF units
  • Positive: ≥ 10 JDF units
  • GADA:

  • Negative: < 5 IU/mL
  • Positive: ≥ 5 IU/mL
  • IA-2A:

  • Negative: < 0.9
  • Positive: ≥ 0.9
  • IAA:

  • Negative: < 95 nU/mL
  • Indeterminate: 95 – 125 nU/mL
  • Positive: > 125 nU/mL
  • ZnT8A:

  • Negative: ≤ 15 U/mL
  • Positive: > 15 U/mL