Islet Cell Antibody (IA-2) Screen with Reflex to Titer
This test measures IA-2 antibodies, an islet autoantibody used in screening for presymptomatic type 1 diabetes (T1D). If the initial screen is positive, the laboratory automatically runs an antibody titer on the same sample.
About this test
IA-2 antibodies are described by Quest as a key marker of type 1 diabetes (T1D) autoimmunity, and their presence is associated with more advanced islet autoimmunity and faster progression to stage 3 T1D. The screen is used to look for presymptomatic T1D in people with a family history of the condition or a high-risk HLA genotype, and to help differentiate T1D from type 2 diabetes and from atypical forms such as latent autoimmune diabetes in adults.
Quest notes that classifying diabetes type can be difficult at diagnosis, with misclassification occurring in about 40% of adults with new T1D. Because identifying a presymptomatic stage requires at least two positive islet autoantibodies, professional organizations recommend testing for all four recognized markers — IAA, GAD65, ZnT8 and IA-2 — rather than relying on IA-2 alone.
Test details
| Collection | Quest patient service center |
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Quest resources
Additional details
What this test looks at
The test first reports whether an Islet Cell Antibody Screen (IA-2) is positive or negative, from a 2 mL serum sample analyzed by immunofluorescence assay, ideally collected while fasting. If the screen is positive, the laboratory automatically runs an Islet Cell Antibody Titer on the same sample, so a positive screen does not require a separate order for the titer step.
This test isn't part of the Celio Health store at the moment, so it can't be ordered or requested here. The test menu lists everything that can.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures IA-2 antibodies, an islet autoantibody Quest associates with type 1 diabetes autoimmunity.
How is the sample collected?
The test uses a 2 mL serum sample from a routine blood draw.
Do I need to prepare for this test?
Quest lists fasting as preferred before the blood draw for this test, though water is fine.
What happens if my screen result is positive?
The laboratory automatically runs an Islet Cell Antibody Titer on the same sample.
Does a positive result mean I have type 1 diabetes?
No. This screen is used for monitoring or screening, not diagnosis on its own; Quest notes that identifying presymptomatic T1D relies on testing for multiple islet autoantibodies together, not IA-2 alone.