People with type-1 diabetes were found to have around twice as many cells with a maternal origin than unaffected individuals. This may mirror movement of stem cells from mother to embryo if damaged pancreatic tissue is detected.
For the study, whole blood samples were collected from 94 individuals with type-1 diabetes, 54 unaffected siblings and 24 unrelated healthy volunteers.
Extracted DNA was then analysed using real time polymerase chain reaction assays that targeted maternal-specific alleles to identify and quantify cells with a maternal origin.
Cells with a maternal origin were found in 51 per cent of people with type-1 diabetes, 33 per cent of unaffected siblings and 17 per cent of healthy volunteers.
In people with type-1 diabetes, maternal chimeric DNA was present at levels five times higher than in unaffected siblings and almost 30 times higher than in healthy subjects.
Also, the researchers looked for examined female islet beta-cells in pancreatic autopsy specimens from four unrelated males, one of whom had type-1 diabetes.
Maternal cells were found in all four pancreatic samples. In the pancreas from the type-1 diabetic, 0.96 per cent of beta-cells were maternal, compared with 0.59 per cent in controls.