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Anti-GAD65 Antibody (Serum/Plasma)

Published: August 9, 2026Updated: August 16, 2026

This test measures the presence of antibodies against the GAD65 protein, which is linked to certain autoimmune conditions affecting the pancreas and nervous system.

Quick summary

["This test helps diagnose or monitor conditions like type 1 diabetes or autoimmune neuropathy."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
112067-4
Short code
GAD65 Ab SerPl IA-aCnc
Synonyms
GAD65 Ab SerPl IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms of diabetes (such as frequent urination, extreme thirst, or unexplained weight loss), unexplained nerve problems (like tingling or weakness), or if you have a family history of autoimmune diseases. It may also be used to assess your response to treatment for these conditions.

What to Expect Before the Test

No special preparation is needed. You may have a blood sample drawn from a vein in your arm. If you’re taking blood thinners, let your provider know before the test.

What the Test Results Mean

Positive results suggest an immune response targeting GAD65, which can indicate conditions like type 1 diabetes or other autoimmune disorders. However, results alone don’t diagnose a condition—they’re used alongside other tests and symptoms.

Common Conditions Linked to This Test

High levels of GAD65 antibodies are often found in people with type 1 diabetes, where the immune system attacks insulin-producing cells in the pancreas. They may also appear in autoimmune neuropathy or other rare autoimmune conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

GAD65 Antibody

Frequently asked questions

How often will I need this test?
Your provider will determine how often you need retests based on your symptoms, treatment plan, and test results. Some people may need follow-up tests every few months or annually.
What if my test results are abnormal?
Abnormal results may lead to further testing, such as glucose monitoring or additional bloodwork, to confirm or explore underlying conditions. Your provider will discuss next steps with you.
Does this test affect my medications?
No, this blood test does not directly affect your medications. However, if you’re on diabetes or autoimmune treatments, your provider may adjust your plan based on test results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy