My son had an anti-GAD test of 0.5, his hemoglobin A1c was 5%, and he was diagnosed with diabetes due to an autoimmune problem. The doctor has not answered all of my questions concerning what labs confirm this diagnosis. What other lab tests should he have done? We are only checking his sugar levels one daily. Is this normal?

I think that you might begin by checking the hemoglobin A1c and the anti-GAD levels with your son’s diabetes doctor. I say this because an A1c of only 5% would be very unusual indeed for a toddler, somewhere in the 8% range would be more probable. However, if it is indeed correct it at least raises the possibility that your son might have type 1B or idiopathic diabetes and that the diminishing need for insulin reflects a different type of diabetes rather than a honeymoon period.

By the same token, I would ask about the interpretation of the anti-GAD level. Laboratories are required to state their normal range, and while some still give actual figures for antibody results, it is now more usual to simply state whether the test is positive or negative based on the degree of variation from a substantial number of normal tests.

If enquiry confirms that your son does indeed have type 1A (autoimmune) diabetes on the basis of the anti GAD test, then it would be important to find out whether in fact he actually has what is now called the Autoimmune Polyglandular Syndrome Type II in which the diabetes is accompanied by a variable spectrum of other autoimmune problems. By far the most common of these is hypothyroidism and after that the celiac syndrome which can be tested for by an antitransglutaminase test. These two possibilities should be routinely checked at this juncture, and if it is readily available some centers also do an anti 21-hydroxylase test for adrenal autoimmunity, but more with the objective of being forewarned if there is a problem later. A single blood sugar assay before breakfast would not nowadays be considered adequate unless, of course his A1c really is entirely normal.

DOB