Bone marrow transplant hope for diabetes

A research team comprised of scientists in Brazil and Northwestern University, Chicago has shown that they were able to reverse or halt the progression of Type 1 diabetes in newly diagnosed individuals using injections of the patients' own stem cells. Of the fifteen volunteers treated, all but one were able to function without insulin injections for time periods varying from a few weeks to a number of months. One of the subjects was insulin free for nearly three years and four were insulin free for two years. Dr Richard Burt, co-author of the study, published in the Journal of the American Medical Association said he expected the work would 'generate controversy and interest and excitement.'

Type 1 diabetes is caused by the patient's own immune system attacking the cells in the pancreas that produce insulin. If insulin cannot be produced, sugar levels in the blood rise, and damage may occur to kidneys, nerves and eyes. The disease usually begins in childhood or adolescence, rarely adults may be diagnosed with the condition. People with Type 1 diabetes must inject insulin up to four times a day to control sugar levels.

The team experimented on fifteen adults that had been diagnosed with Type 1 diabetes mellitus in Sao Paulo during the previous six weeks. Adults were used for the experiments as they were able to give informed consent for the research. The researchers first removed bone marrow from the patients and then gave them drugs to destroy their immune system. The treatment was similar to - although less severe than - the type of chemotherapy given in cancer treatments as radiotherapy was not used. As the patients were then vulnerable to infection, they were isolated in hospital and given antibiotics. After two weeks they were then given a mixture of their own stem cells, injected into the jugular vein, to re-establish their immune system. This method, which has also been used in treating Crohn's disease and Lupus, is known as autologous nonmyeloablative haematopoietic stem cell transplantation. This means that nothing special has been done to the patient's stem cells and no special types are preferred for re-injection.

The researchers speculate that the stem cells re-set the immune system of the volunteers, enabling new immune cells to be established that do not target the pancreas. It is also possible that the treatment led to growth of new insulin producing cells or there may be a mechanism that is not yet understood that protected the existing cells or encouraged them to produce more insulin. The study was described by Dr Iain Frame of the charity Diabetes UK as 'very preliminary'. He explained that: 'It is well known that there is often a honeymoon period of relative remission after the onset of Type 1 diabetes that complicates the interpretation of results such as the ones shown in this study. All these issues need to be addressed through more research before there are any conclusive findings in this area'. Other criticisms of the research pointed to the small study cohort and the lack of suitable matched controls.