JDRF-funded researchers Ms Eliana Mariño and Dr Shane Grey have demonstrated the cells of the human immune system can be manipulated to prevent type 1 diabetes.

The body’s immune cells, or white blood cells, include B cells and T cells. B cells make antibodies and present ‘antigens’ to T cells, allowing them to recognise and kill invaders.

Previous research by the authors has showed that groups of B cells migrate to the pancreas and pancreatic lymph nodes and tell T cells to kill the cells that produce insulin.

Working with mice that spontaneously develop type 1 diabetes, the team used a special molecule called BCMA to block a hormone responsible for controlling the survival of B cells, called BAFF. As the B cells were removed using this technique, a special type of T cell (called regulatory T cells) increased and prevented the autoimmune attack on the pancreatic cells.

They found that after this treatment, none of the mice developed type 1 diabetes – a remarkable finding, as other B cell depletion methods have just delayed or reduced disease incidence.

The molecule BCMA is already being used in clinical trials for other autoimmune diseases, such as Sjogren’s Syndrome and Lupus and this result provides support for the development of a human type 1 diabetes trial.

This work was conducted under the auspices of the Diabetes Vaccine Development Centre (DVDC) at the Garvan Institute of Medical Research in Sydney.

Diabetes published online April 29 2009

There is extensive research to show that tight blood glucose control is the best way to prevent the onset of type 1 diabetes complications such as kidney failure, retinopathy and heart disease. According to results from the Diabetes Complications and Control Trial, every one point reduction in HbA1C reduces the risk of long-term complications by approximately 40%.

Unfortunately, research has also shown that one of the hurdles to tight blood sugar control is the risk of hypoglycemia – both real and perceived.

Over the past 15 years the use of different insulin analogs as well as improvements in insulin pumps and blood glucose monitoring has had a positive impact on the ability of people to achieve blood sugar control targets. The rates of severe hypoglycemia, however, remain high and occurrence of such events is often followed by a decline of glycemic control due to fears of further hypoglycemic episodes.

In two multi-centre clinical trials – the first concentrating on people with bad glycemic control and the second on people who intensively manage their blood sugars – JDRF researchers have now demonstrated that an excellent solution to this problem is the use of a continuous glucose monitor, or CGM.

According to these trials, people using CGM spent two hours more time per day in the target blood sugar range of 3.9 to 10.0 mmol/l compared with people using fingerprick testing alone. They also found that CGM subjects had a significant overall improvement in HbA1C over time without an increased number of hypoglycemic attacks.

CGM devices are worn in a similar fashion to an insulin pump and provide both a real-time snapshot of glucose levels as well as trend information on whether glucose is moving up or down. They can also provide a warning when glucose is becoming too high or too low.

The continuous glucose monitor is a key component of the JDRF international Artificial Pancreas Program and these results take researchers one step closer to making the artificial pancreas a reality.

Diabetes Care published online 25th May 2009