Your pancreas needs the enzyme glutamic acid decarboxylase (GAD) to function normally. Antibodies that target this enzyme are called GAD antibodies.

An antibody is a protein that your immune system uses to attack foreign objects. Those foreign objects, such as viruses or bacteria, are often potentially harmful.

Sometimes, the immune system makes autoantibodies, which are antibodies that mistakenly attack normal cells that aren’t harmful. When that happens, it causes an autoimmune disorder.

About 75 percent of people with type 1 diabetes have GAD autoantibodies in their blood.

Your doctor will use diagnostic tools to diagnose diabetes, such as checking for high glucose and a high HbA1c. Once they can diagnose diabetes, they’ll take steps to determine if it’s type 1 or 2.

Type 1 diabetes and type 2 diabetes are two distinct conditions. Each requires a specific approach to management and treatment.

Your doctor may order a GAD test to find out more about your condition. You might also hear this test referred to as GADA or anti-GAD. Or your doctor may recommend an autoantibody panel to test for GAD and other antibodies.

Other antibodies associated with type 1 diabetes include:

  • islet cell cytoplasmic autoantibodies (ICAs)
  • insulinoma-associated-2 autoantibodies (IA-2As)
  • insulin autoantibodies (IAAs), which are more common in children than adults

All these tests are done through a simple blood test. You won’t need to do anything to prepare, such as fasting. A healthcare provider will take blood from a vein in your arm and send it to a laboratory for analysis.

If GAD or any of the other autoantibodies are found, it means you most likely have type 1 diabetes. If no GAD or other autoantibodies are found, you probably have type 2.

Type 1 diabetes is the result of an immune system malfunction. It starts when your immune system attacks and destroys beta cells in your pancreas. These are the cells that produce insulin, a hormone necessary to regulate blood glucose levels.

Once your immune system destroys pancreatic beta cells, they can’t be repaired. Without insulin, glucose builds up in your blood and leaves your cells starved for energy.

In type 2 diabetes, your pancreas may not be producing enough insulin or your body isn’t using it efficiently. Type 2 diabetes starts as insulin resistance. The presence of GAD autoantibodies indicates an immune system attack, which points to type 1 diabetes.

Type 1 diabetes isn’t the only reason someone might have GAD autoantibodies. These antibodies are also linked to other conditions, which include:

If you’ve been diagnosed with diabetes and you have GAD autoantibodies, it’s likely that you have type 1 diabetes.

If you’re being tested for GAD, chances are you’ve had symptoms of diabetes or you’ve been diagnosed with diabetes.

Diabetes symptoms include:

  • excessive thirst and hunger
  • frequent urination
  • irritability
  • blurry vision
  • fatigue
  • weakness
  • weight loss
  • cuts or sores that take a long time to heal

Yes. If diabetes isn’t treated, it can cause serious and even life threatening complications, including:

  • vision problems
  • nerve damage
  • cardiovascular disease
  • kidney damage

Both type 1 and type 2 diabetes can be successfully managed. The main goal is to keep your blood glucose levels under control. This will help prevent some of the potential complications of diabetes.


Diet is important in the management of diabetes. You’ll need make sure your glucose levels are within an optimal range throughout the day. Your doctor will give you recommendations for a diet that’s high in nutritional value but low in empty calories.


Engaging in regular physical activity is another way to keep your blood glucose levels in the optimal range.


If you have type 2 diabetes, you might need medication. If you do, several oral medications are available to help keep glucose levels under control.

All people with type 1 diabetes and some people with type 2 diabetes need insulin therapy. This requires monitoring your blood glucose levels so you know how much insulin you need.

Insulin therapy involves injecting insulin just under the skin. You should rotate injection sites to avoid skin irritation.

Some types of insulin are meant to act quickly and last for a short time. Others are designed to be long acting. Your doctor will advise you how and when to use each type.

You can also use an insulin pump, which is a device you can wear on the outside of your body. The pump makes it easier to deliver insulin when you need it. This is especially helpful if you have type 1 diabetes or if you have type 2 and need insulin injections several times per day.

Your treatment plan may change over time. If you have any complications of diabetes, your doctor will also need to address those.

There’s no cure for type 1 diabetes. But researchers are working on “cures,” such as a pancreas transplant or a stem cell transplant. Islet cells (or beta cells) grown through stem cell technology are starting to show promise as research continues.

If you have type 2 diabetes, it’s possible to get your blood glucose levels in the normal range for long periods and reduce or eliminate your need for medication.

That said, you’ll always need to stick to healthy lifestyle habits and monitor your blood glucose levels to be certain you’re still producing the right amount of insulin.

Treatment for diabetes has come a long way. In addition to a healthy lifestyle, there are medications available to help keep diabetes under control and reduce the risk of complications.