December 18, 2000
Diagnosis and Symptoms
Question from Las Vegas, Nevada, USA:
I'm very confused about my diagnosis. I have no diabetes in the family. I am 16 years old, and 20% underweight for my height. So, seven months ago, when a glucose tolerance test indicated diabetes, I was given the label "type 1 diabetic" by my primary doctor. I was later tested for both GAD and islet cell antibodies. Both were negative, yet my endocrinologist is still certain it's type 1. I was also diagnosed with celiac disease (with antibodies) and had positive thyroid antibodies (my mom has an underactive thyroid). Can it still be type 1 without antibodies? Could it possibly be type 2, like my previous endocrinologist thought?
Your endocrinologist is quite right. I am sure that you do indeed have type 1A or autoimmune diabetes, or more particularly you have a group of autoimmune conditions together which is known as the Autoimmune Polyglandular Syndrome The most common components of this are diabetes, hypothyroidism, and celiac disease, but there are many other rarer possibilities. You didn’t say whether you were on insulin, but the various components of this syndrome do develop at different rates.
The apparently negative antibody tests probably have a technical explanation, and you should ask your endocrinologist whether or not the laboratory did the most up to date test which includes anti insulin (IAA), anti GAD65 and anti ICA512. If in fact you had the screening immunofluorescent ICA test, this can be difficult to interpret and it is also possible a positive anti GAD has not yet developed. It probably isn’t worth repeating these tests because the antitransglutaminase test for celiac syndrome and the anti-thyroid antibodies really define the type of diabetes. In an case, it doesn’t make any difference to treatment which is always to keep blood sugars as near to normal as possible.