Since I last corresponded with you, my two-year-old son has been having wide blood sugar swings. He had a seizure on September 2, cause unknown at this point, but they are doing an EEG and MRI this month. In the last few days, he had more blood sugars in the high 200s mg/dl [around 16 mmol/L]. The last two days, there were some in the 300s mg/dl [over 16.7 mmol/L]. I also had my monitor register a “hi” reading, but I retested and it again showed in the 300s mg/dl [over 16.7 mmol/L]. I just got some test results back. They did an Islet Cell 1gAb (I’m not sure if I wrote it down right) and an anti-GAD-65. The Islet cell came back as “present but low (>1:4)” and the Anti-GAD came back high at 66.6. I do finally have a appointment with the endocrinologist on October 5 but it was like pulling teeth to get one. I would like to know what these test results mean. I looked on the Internet but it is hard to understand the medical language. Am I understanding that he doesn’t necessarily have diabetes but he could get it? That is what the endocrinologist told my pediatrician. I’m fine with that, but will we just not worry about the sugar levels until he develops more symptoms?

The tests that were done were for the detection of “anti-pancreas” immunoglobulin (antibody) proteins. The first one that you listed as “Islet Cell 1gAb” (which you indeed you may written incorrectly) is a common antibody immunoglobulin detectable in type 1 diabetes. The level of “>1:4” means that it was only detectable in small amounts (i.e., they could only detect it with the whole sample, a 50/50 dilution [or 1:2] and then another 50% dilution of that [1:4]. A high concentration of such antibodies might be detectable in several more serial dilutions.) The Islet Cell antibodies are sometimes called ICA antibodies, ICA512 antibodies, and IA-2 antibodies.

The second antibody that was measured is what we call the GAD antibody, which stands for “Glutamic Acid Decarboxylase” antibody. GAD is an enzyme protein within the insulin producing cells. Antibodies to GAD may be the most common antibody marker for risk of type 1 diabetes. The amount of this antibody was measured directly (and not in serial dilutions). Thus, the value of “66.6” probably had some unit of measurement such as “U/mL.” So, “66.6 Units of GAD per every 1 milliliter of blood.” Normally, such antibodies should not be detected.

These antibody risks mean that your child has the RISK for the development of type 1 diabetes. I cannot tell you that this is a high or low risk, but it is not zero risk. Having these risk factors is NOT the same as saying that the child “WILL” develop type 1 diabetes, for several reasons. One reason is that laboratory tests can be wrong as no test is perfect. There are “false positive” (and “false negative”) results. But, in addition, a “risk” is simply that…a RISK.

So, the presence of antibodies infers a relative larger risk for type 1 diabetes for your child. Keep that appointment as the child may need to undergo better tests to confirm whether diabetes mellitus is present right now. If not present, then talk to the pediatric endocrinologist about enrolling your child in TrialNet, a large national study looking to PREVENT the progression and development of type 1 diabetes in people at risk.

DS