April 5, 2009
Diagnosis and Symptoms
Question from Mount Crawford, Virginia, USA:
My 11-year-old son was diagnosed with type 1 diabetes three weeks ago. We were told during our hospital admission at the University of Virginia that people diagnosed with type 1 diabetes usually have a genetic predisposition to the disease and that they have antibodies that can be triggered by what they think is probably a viral illness that destroys the islet cells in the pancreas. When we went to our follow-up appointment one week ago, we were told that our son carried no antibodies for type 1 diabetes. Our endocrinologist said this is rare and they usually don't see this. They repeated some more blood work for more specific testing but didn't really explain what for. Obviously, I will be in contact with them regarding the results but I don't understand what it means to not carry antibodies. All they told me is that it is a good thing because it makes my other children not at risk and my son's future children not at risk. Can just a viral illness kill the islet cells even if you have no antibodies? How often does this occur?
The antibody tests are only positive about 60 to 80% of the time. That does not mean this is not a case of autoimmune diabetes, only that the antibody levels were not high enough to show up on the blood samples. It would depend on which antibodies were actually tested and in which laboratory. For instance, if all four antibodies were tested, this would have more meaning than if only the most common islet cell antibody were tested. You can review this with the excellent team at the University. If the pancreas were closer to the surface and a biopsy were possible in a simple and safe fashion, it would be likely that there would be autoimmune attack cells present.
I’m not sure that I would agree with the notion that because there were no antibodies present in one child, the other children are less susceptible. This is mixing up genetic causation with specific antibodies and is a bit more of a leap that is correct.
Lastly, we do not know exact causes of diabetes. Viruses are one possibility. Other (unknown) environmental exposures are also a possibility, i.e., obesity, vitamin D insufficiency, chemicals. And, at the moment, both of these are not amenable to specific intervention since they are either unknown or unavailable.