August 9, 2009
Diagnosis and Symptoms
Question from Dominican Republic:
My four-year-old daughter was diagnosed with diabetes a month ago. This is pretty new and is very hard for my family. The doctor sent a test to the U.S. and we received the results today. What do these results mean? Islet Cell IgG Autoantibodies Result 80* Abnormal Flag Code: A; Insulin Antibodies less than 0.1; and Glutamic Acid Decarboxylase (GAD) Autoabs, Result 85.9* Abnormal Flag Code: H.
As I hope that your doctors have explained (or that you have read in educational materials given to you) the majority of cases of type 1 diabetes in children is caused by a process in which the body’s own immune system begins to “attack” the pancreas and its ability to manufacture insulin. Of course, normally, the body’s immune system should attack “foreign” things, such as germs and viruses, but sometimes – and this is not best understood, the body’s immune system begins to attack normal body organs and cells as if they were “foreign.” This is called an autoimmune disease. A way to help think about this is how the body might try to reject a transplanted organ: in an autoimmune disease, the body begins to “reject” some specific organs that should not be attacked. There are many autoimmune diseases and there often is a trend for them to occur in families. Examples include several thyroid diseases, rheumatoid arthritis, systemic lupus, Vitamin B12 deficiency (“pernicious”) anemia, multiple sclerosis, adrenal gland diseases, celiac disease, and certainly type 1 diabetes.
In order to confirm that your child’s diabetes was indeed autoimmune type 1 diabetes, the blood samples sent were for measurement of three of the more common immune-protein antibodies that become measurable in type 1 diabetes. The most commonly found antibody is the glutamic acid decarboxylase autoantibody. Normally, such antibodies should not be present (a level of “0”). But, your child’s value is fairly high. Glutamic acid decarboxylase is an enzyme that is important in the “islet cells” (“EYE-let”) of the pancreas where insulin is produced. The other antibody your doctor checked is an antibody to insulin itself. Again, such antibodies should not be present and indeed were not detectable (“less than 0.1”) in your child. Insulin antibodies are more commonly measurable in very young children (toddlers) diagnosed with type 1 diabetes. Another common antibody is the islet cell antibody. Again a normal value should be “zero” but such antibodies were measurable in your child. The common protein that islet cell antibodies attack is another enzyme within the islet cells. The level of the antibodies is really not so important; more important is whether such antibodies are detectable or not. The presence of the islet and glutamic acid decarboxylase antibodies confirm that your child has the common, “run-of-the-mill,” form of type 1 diabetes. But, this also means that your child is at slightly higher risk of the development of other autoimmune diseases, including (but not limited to) the ones listed above. You should talk to you doctor about other conditions that your child may need to be screened for given the confirmation of autoimmune type 1 diabetes.