Type 1 diabetes: hope for stem cell transplants after initial success

A 64-year-old American with type 1 diabetesthe autoimmune form of the disease in which insulin-producing cells are destroyed, can regulate its insulin production and its blood sugar without the need for medication by injecting stem cells into the blood. Vertex, the biotech company leading the clinical trial, chose a cell-scale approach. In the pancreas, only pancreatic β cells in the islets of Langerhans secrete insulin. Using a protocol developed at Harvardembryonic stem cells were transformed in vitro in pancreatic β cells. These are injected into the bloodstream and replace defective cells in the pancreas. This 64-year-old American is the first patient for whom the protocol is a success.

A cell transplant to correct type 1 diabetes

the dosage of C-peptide, a small protein synthesized at the same time and in the same quantity as insulin and which serves as a marker for the activity of pancreatic β cells, increased from 0 to 280 and 560 pmol/L, during a period of fasting and meal respectively. The patient, who had to inject 30 to 34 units of insulin every day before the graft to survive, today only needs three units. The next step will consist of repeating the experience in 17 additional patients, treated in independent centers.

If the scientists manage to reproduce the same results in other patients, then diabetes type 1 to be well treated by a transplant of differentiated stem cells, but at the cost of a immunosuppressive therapy for life. Scientists are also working to make the immune system tolerant towards transplanted stem cells. ViaCycle, another company specializing in the treatment of diabetes type 1, has tested several devices to protect stem cells of the immune system in a membrane, but without conclusive results to date.

Type 1 diabetes: success of pancreatic cell transplantation

Article published on September 8, 2009 by Destination Santé

A team from Inserm in Lille has announced very encouraging results five years after transplanting cells from the pancreas, which produce insulin, in patients with a severe form of type 1 diabetes, who no longer secreted insulin. all.

In 2004, an Inserm team led by François Pattou, in Lille, announced the success of a pancreatic cell transplant in a patient with type 1 diabetes. Five years later, 14 diabetics benefited from this new technique, with results deemed very satisfactory.

All the patients treated had a severe form of type 1 diabetes, without any secretion of insulin. ” After 3 to 6 years of follow-up, 11 patients (79%) showed satisfactory glycemic controlsays François Pattou. For eight of them, this result was made possible without any injection of insulin. The three patients who subsequently lost their graft returned to their previous situation, after stopping the anti-rejection treatment. »

A major intervention, to be reserved for the most serious cases

The need for a powerful anti-rejection treatment remains a major obstacle to the development of the technique. This constraint requires careful monitoring to quickly detect and treat complications – infectious or tumoral – favored by the reduction of immune defences.

For the author, ” this new approach remains (therefore) reserved for the most unstable forms of diabetes, for which the prognosis is life-threatening “.