Researchers are getting very excited about an innovative new stem-cell study, published in the latest issue of the Journal of the American Medical Association, which permitted some type 1 diabetes patients to stop taking insulin.

The preliminary study, which can be found in the April 11 issue of JAMA and was carried out at the University of Sao Paulo in Ribeirao Preto, Brazil, claims that a therapy that includes stem cell transplantation induced extended insulin independence in patients with type 1 diabetes.

The authors of the study, led by Julio Voltarelli of the University of Sao Paulo and Richard Burt of Chicago’s Northwestern University, examined the effect of high-dose immunosuppression followed by autologous nonmyeloablative haematopoietic stem cell transplantation (AHST) to preserve beta-cell function in 15 newly diagnosed patients with type 1 diabetes.

The disease results from an autoimmune attack against pancreatic beta cells and at the time of clinical diagnosis, approximately 60- 80% of the beta-cell mass has been destroyed, the study notes, adding that beta-cell preservation has been shown to be an important target in the management of type 1 diabetes and in the prevention of its related complications, such as blindness, kidney failure and heart disease. AHST, which uses a patient's own blood stem cells, involves the removal and treatment of the stem cells, and their return to the patient by intravenous injection.

Data from the study showed that during a 7 to 36-month follow-up, 14 patients became insulin-free – one for 35 months, four for at least 21 months, seven for at least six months; and two with late response were insulin-free for one and five months, respectively). Among those, one patient resumed insulin use one year after AHST and the only severe adverse effects were pneumonia in one patient and endocrine dysfunction in two others.

Follow-up studies necessary

The authors described the results as “very encouraging,” given that 93% of patients achieved different periods of insulin independence and treatment-related toxicity was low, with no mortality. They acknowledged that further follow-up is necessary to confirm the duration of insulin independence and the mechanisms of action of the procedure and noted that “randomised controlled trials and further biological studies are necessary to confirm the role of this treatment in changing the natural history of type 1 diabetes and to evaluate the contribution of haematopoietic stem cells to this change."

In an accompanying editorial, Jay Skyler of the Diabetes Research Institute in Miami, said that the study by Dr Voltarelli et al “is the first of what likely will be many attempts at cellular therapy to interdict the type 1 diabetes disease process.” This will include infusion of dendritic cells, T-regulatory lymphocytes, umbilical cord cells, embryonic or adult stem cells, and allogenic bone marrow transplantation in addition to further studies with AHST, he added.

Dr Skyler concluded by noting that “research in this field is likely to explode in the next few years and should include randomised controlled trials as well as mechanistic studies,” concluding that “the time may indeed be coming for starting to reverse and prevent type 1 diabetes."

The Voltarelli/Burt study has been lauded in some circles as the start of a revolution in the treatment of type 1 diabetes and results suggesting that insulin-dependent patients can be freed from reliance on needles by an injection of their own stem cells have been welcomed. However, some observers have expressed concern over whether the risks of stem-cell transplantation outweigh the inconvenience of being dependent on insulin, while others expressed concern that patients as young as 14 took part in the Brazilian study, which was published just as the future of stem-cell research in the USA was being debated in Congress.