循環血中遊離DNAを用いた膵β細胞傷害の新規検出法の確立

In people with type１ diabetes（T１D）, biomarkers that can sensitively and quantitatively evaluate injury of pancreatic beta cell are required in order to predict the onset of the disease at an early stage and to provide interventions to prevent the progression of the disease. We developed a new method for quantifying pancreatic beta cell-derived insulin DNA in circulation that combines bisulfite conversion and Amplification Refractory Mutation System（ARMS）PCR, which can be performed using a conventional real-time PCR system. We applied this method to T１D patients and healthy adults, both could be detected in about ３０％ of cases. The results in healthy adults indicate that this method may have sensitivity to detect the turnover of pancreatic beta cells at physiological conditions. In post-onset T１D patients, there were many negatives because the amount of residual pancreatic beta cells was extremely small. However, in some cases with a short duration of the disease, pancreatic beta cell-derived insulin DNA was detected in negative correlation between the duration of the disease, that suggested the residual pancreatic beta cells continue to be slowly destroyed. It was demonstrated that the time course of pathophysiology in T１D could be understood using this method.