February 21, 2006
Research: Causes and Prevention
Question from Wayland, Massachusetts, USA:
I am curious to know how many people with type 1 diabetes are positive for the autoantibodies that, when triggered, cause the autoimmune attack on the beta cells. Do you have to have the HLA gene in addition to the autoantibodies? If one does not have the autoantibodies, does this mean that other causes such as viral or trauma are the cause? Are these routine laboratory tests or do you have to request that they are done?
About 60 to 80% of type 1 diabetes patients will be positive for one of the islet cell antibodies when done in research laboratories. Nothing is known when such tests are done with commercial laboratories. Negative tests just mean negative tests and do not imply lack of autoimmunity. Whether a virus or other environmental factors are the triggers is also not related to antibody status. There are some strong associations and links with different patterns of islet cell antibodies, but they are difficult to utilize for any individual, more useful with large studies looking for broad association and correlations. There is not much reason to do routine islet cell antibody testing in newly diagnosed type 1 diabetes unless part of a research study looking for causes since it does not help much with treatment decisions. If there is some question, of what type of diabetes a person has, then antibody status may imply earlier use and need of insulin.