Types of antibody tests: Glutamic Acid Decarboxylases (GADA); Insulin-Associated Tyrosine Phosphatase Antibody (IA2A); Insulin Autoantibody (IAA); Islet Cell Antibody (ICA)

What are they? Antibody tests are used to distinguish between the types of diabetes. An antibody is a type of protein produced when the immune system mistakes healthy tissue for a harmful substance. Antibody tests can determine if your body has produced antibodies against insulin. Such autoimmune activity is specific to type 1. Type 2 is not an autoimmune disorder.

Why are these tests performed? When a diagnosis of diabetes is made, antibody tests can be ordered to determine if it is type 1 or type 2. Antibodies will only be present in type 1 diabetes. An antibody test may also be ordered if you appear to have an allergic reaction to insulin or if insulin no longer seems to control your diabetes.

How are these tests performed? During antibody tests, blood is drawn from a vein, usually from inside the elbow or from the back of the hand. In the lab, a test that makes protein in the blood visible is performed.

What do my results mean? Normally, there are no antibodies against insulin in your blood.

What do abnormal results mean? If the IgG and IgM types of antibodies against insulin are present in your blood, it means that your body acts as if insulin is a foreign object. This can change the amount of time it takes for insulin to act and make insulin less effective, or not effective at all. The insulin is not able to perform its function of moving glucose from the blood stream into cells. An elevated level of the IgE antibody against insulin indicates that you have developed an allergic reaction to insulin.

What is LADA? Latent autoimmune diabetes, also nicknamed "Diabetes type 1.5", is a subtype of diabetes that is often considered to be a slowed onset of type 1 diabetes.  However, LADA displays characteristics of both type 1 and type 2 diabetes, which can make diagnosis a confusing process.  In an antibody test, LADA will show positive for antibodies against insulin in the body, much like a type 1 diagnosis.  However, researchers also found that 10% of diabetes patients who were diagnosed with type 2 also showed positive for these antibodies in screenings.  After discovering that LADA patients also did not require insulin injections upon diagnosis, which further distinguished them from type 1 patients, doctors determined that LADA was a completely unique form of diabetes diagnosis.      

Reviewed by Susan Weiner, RD, MS, CDE, CDN. 05/12

Last Modified Date: May 15, 2013

All content on is created and reviewed in compliance with our editorial policy.

More on this Topic

No items are associated with this tag

Sign up for FREE dLife Newsletters

dLife Membership is FREE! Get exclusive access, free recipes, newsletters, savings, and much more! FPO

You are subscribed!
You are subscribed!
You are subscribed!
2073 Views 0 comments
by Brenda Bell
Well maybe not so much a furor as a controversy. The question, bluntly put, is whether or not a single HbA1c reading should be sufficient and adequate to diagnose diabetes — and whether the conditions under which the test was conducted should have any bearing on the diagnostic or non-diagnostic value of the test. The lede from
  • Watch dLifeTV online now!

    Click here for more info