I have written in the past about the predictive value of knowing that there is a "possibility" of developing Type 1 diabetes. At present, the incidence of type 1 diabetes is approximately 1 in 300 worldwide. Some families wish to know everything despite the lack of a cure; others feel that since no cure is available, why worry unnecessarily as there is nothing that one can do to prevent Type 1 diabetes at this time. There is now more definitive information about the timing of screenings in the TrialNet Natural History Study based on a recent Diabetes Care paper by Vehik, Bean, Mahon, Schatz, Haller, Sosenko, Skyler and Krischer for the TrialNet Natural History Study Group (DOI: 10.2337/dc11-0560): "Development of Autoantibodies in the TrialNet Natural History Study."
The TrialNet Natural History Study was initiated to help predict the possible future development of autoimmune Type 1 diabetes based on the presence of islet autoantibodies. In most cases, pancreatic islet cell autoantibodies precede the onset of T1DM and thus can identify those people at greatest risk. According to the authors, the most important predictive antibodies at present are:
|
|
Frequency: high risk |
low risk |
|
Antibodies |
Population: T1DM |
Population: general |
|
Glutamic acid decarboxylase (GAD-65) |
4% |
1% |
|
Insulinoma-associated protein (ICA512) |
2% |
0.6% |
|
Insulin (mIAA) |
3% |
1.1% |
This study assessed the rates of seroconversion to GAD-65, insulin positive (mIAA), and ICA512 in a group of relatives of type 1 diabetes patients undergoing screening in TrialNet.
What is TrialNet?
Trial Net is composed of multiple clinical centers (18) and 170 affiliates in nine countries. The Trial Net Natural History Study is a prospective cohort study that works to identify future participants for prevention trials and provides information in regard to pre-clinical type 1 diabetes. Screening for the above antibodies was conducted between February 2004 and April 2010 and annual re-screening was offered to antibody negative children under18 years.
What is the relevance of this study?
By understanding the relationship between age and the development of islet autoantibody seroconversion, it is possible to establish the optimal screening intervals to determine the risk for Type 1 Diabetes. Most importantly, it may help to reassure families that their children are extremely unlikely to develop Type 1 diabetes or that their children may be at a greater risk and thus be prepared for the development of diabetes related symptoms.
