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GAD antibodies

Blood sugar and diabetes · also printed as Anti-GAD, GAD65 antibodies, Glutamic acid decarboxylase antibodies, GAD Ab, Anti-GAD65

Typical UK adult rangebelow 5 IU/mL

Most labs print a cut-off, commonly 5 or 10 IU/mL; the lab's own applies.

What this test measures

GAD antibodies are immune proteins directed against an enzyme in the insulin-producing cells of the pancreas. They are a marker of the autoimmune form of diabetes.

Why doctors request it

Doctors request them when it is not clear whether someone's diabetes is type 1 or type 2, or in adults with diabetes that does not behave as expected.

What commonly pushes it up

Autoimmune (type 1 or slowly progressing autoimmune) diabetes
Occasionally other autoimmune conditions
Rarely, a neurological condition called stiff person syndrome

What commonly pushes it down

A negative result is the usual finding in the general population

Everyday reasons for a value outside the range

Low positive results occur in a small share of people without diabetes
Units and thresholds differ between labs

About the sample

No fasting needed. Often requested alongside IA-2 and zinc transporter 8 antibodies.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.

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This is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.