antibodies to insulin
This test measures whether you make antibodies to insulin. IAA (serum
) Blood test to measure whether you have type I diabetes mellitus or are at increased risk of developing it
This test is also used to assess aptitude and for first-degree relatives.
This test is done for patients with diabetes when it is unclear what type of diabetes it is.
The test determines the amount of antibodies to glutamic acid decarboxylase (GAD) in blood. These are so-called autoantibodies directed against the insulin-producing cells in the pancreas. Normally, the immune system only makes antibodies against invading bacteria and viruses. Sometimes something goes wrong and antibodies are made against the body's own cells, tissue or organs. These so-called autoantibodies cause damage and inflammation to body tissues and organs, such as the pancreas in this case.
The GAD autoantibodies target the protein glutamic acid decarboxylase which is involved in insulin production in the pancreas. This reaction leads to a disruption of the insulin production and causes type 1 diabetes mellitus. In addition to GAD antibodies, type 1 diabetes is also associated with antibodies to other proteins, such as IA2 antibodies and insulin antibodies. The test for GAD antibodies is the most sensitive for detecting type 1 diabetes in adults.
There are 2 main causes of diabetes.
Type 1 diabetes is an autoimmune disease and occurs when the immune system damages the insulin-producing cells in the pancreas. As a result, the pancreas cannot make insulin, or not enough of it, to maintain sugar levels in the blood. This type of diabetes usually develops at a young age and is also called juvenile diabetes.
Type 2 diabetes is much more common and usually develops later in life.develops. Recent research shows, that DM type 1 can also develop at an older age. With severe obesity, type 2 can develop at an early age.
In these cases the determination of GAD antibodies can give a decisive answer about the cause of the diabetes. This test is usually performed in combination with antibodies against IA2.
Absence of GAD antibodies (negative result) does not rule out a person having DM type 1.
An elevated result (positive result) in a patient with diabetes is almost certainly evidence of type 1 diabetes. This usually means that the patient will need to start injecting insulin soon. The presence of GAD antibodies or other diabetes antibodies in healthy relatives of a patient with type 1 means that these relatives have an increased risk of also developing type 1 diabetes. The more different antibodies present at the same time, the higher the risk.
There are no treatments yet that can prevent the development of type 1 diabetes. People with an increased risk will be checked more often in order to treat the onset of diabetes at an early stage.
IA2 antibodies are more often found positive in children with diabetes mellitus type 1 and
GAD antibodies are more often found positive in adults with type 1 diabetes mellitus.
method used RIAReference range
In children younger than 5 years, 100% of diabetes is Type
IBIn adults, about 20% of diabetes is Type 1 and 80% is Type 2
The higher the antibody titer, the higher the risk of diabetes.