My daughter was diagnosed with type 1 diabetes at the age of 7 on July 5, 2011. She is Caucasian. Since her diagnosis, every antibody screen has been tested and all were negative. Her endocrinologist even tested her for ZnT8, which was negative. The endocrinologist has classified her as type 1b. Her C-Peptide level is 0.9. I know that type 1b is often classified as idiopathic. The endocrinologist suspects she will honeymoon for quite a while. Her A1c is 6.7 now but was 13 at diagnosis. At time of diagnosis, she was in DKA (positive ketones and glucose greater than 1000 mg/dl in her urine) but never required an insulin drip. By allowing her to fast and place subcutaneous insulin on board, her sugars normalized and the DKA resolved. Can you tell me more about this type of diabetes? Why would a child have type 1b? Sometimes, I even question if there is something else, such as a pancreatic mass, causing her to require insulin.

There are about four major diabetes antibodies and all four, when tested as in your child, can be negative in about 10 to 30% of kids – but they still have autoimmune, type 1a, diabetes. It is just that are tests are not as good as we would all like. It turns out that it does not really matter in terms of how the diabetes is treated since treatment is based upon actual blood glucose results and A1c levels obtained and not by antibodies. Once some years have passed, we will also be able to classify how easy or difficult is the type of diabetes she has but this doesn’t help us predict this very well right now. The likelihood of a pancreatic tumor or cyst or some other mass causing this is extremely remote, but you should discuss this with her diabetes team since they would be able to assess better and reassure you. Another way to help classify is to know if she has celiac antibodies or thyroid antibodies since these too can “point” to the classical autoimmune type of diabetes even when the pancreatic antibodies themselves are negative.

SB