Mouse stem cells marked with a fluorescent dye. In the study the patients' own adult stem cells were used to rebuild their 'reprogramed' immune systems following chemotherapy.

Credit: Wikipedia

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CHICAGO: An experimental stem cell therapy has reversed the course of type 1 diabetes and allowed one patient to go without insulin for three years, according to a new study.

"This is the first therapy for type I diabetes to result in drug-free treatment," said immunotherapist Richard Burt of Northwestern University in Chicago, and one of the senior authors behind the study.

Thirteen of the 15 patients who took part in testing the therapy were able to quit the insulin injections that most diabetics depend on and remain insulin-free today. One of the first patients to undergo the procedure has gone three years without using any supplemental synthetic insulin to regulate their blood sugar levels.

While investigators continue to monitor patients' progress, the preliminary results raise the tantalizing possibility that type 1 diabetes may not be a life sentence.

Julio Voltarelli at the University of Sao Paolo School of Medicine in Brazil led the study, which is published today in the Journal of the American Medical Association (JAMA).

Type 1 diabetes accounts for only five to 10 per cent of all cases of the disease, but can result in serious complications including blindness, kidney failure, heart disease, and stroke.

The condition arises when the body's own immune system attacks and destroys the insulin-producing beta cells of the pancreas, causing a shortage in the hormone required to regulate blood sugar. By the time most patients receive a clinical diagnosis, 60 to 80 per cent of their beta cells have been wiped out.

Voltarelli and his team hoped that if they intervened early enough, they could reprogram the body's immune system, allowing the small reservoir of beta cells left to regenerate. To that end, they enrolled diabetics who had been diagnosed within the previous six weeks.

The researchers set out by harvesting adult stem cells from the volunteers. The patients then underwent chemotherapy to wipe out their own immune systems, and were subsequently given transfusions of their own stem cells to rebuild their immune systems.

Fourteen of the 15 - or 93 per cent - were insulin-free for some period of time following the treatment. Eleven of those dispensed with supplemental insulin following treatment and have not had recourse to synthetic insulin since then. Periods of remission range from 36 months for the patient who had the therapy first to six months for more recent graduates of the trial.

Two other patients needed some supplemental insulin for 12 and 20 months after the procedure, but eventually both were able to wean themselves from the synthetic form of the hormone supplied in daily shots.

One patient went 12 months without shots, but relapsed a year after treatment after suffering a viral infection, and resumed daily insulin injections. Another volunteer was eliminated from the study because of complications.

"This study… is the first of what likely will be many attempts at cellular therapy to interdict the type 1 diabetes mellitus disease process," commented Jay Skyler a prominent U.S. diabetes researcher at the University of Miami.

"Research in this field is likely to explode in the next few years," said Skyler in an accompanying JAMA editorial. "As these further studies confirm and build on the results of Voltarelli et al, the time may indeed be coming for starting to reverse and prevent [the disease]."

Further studies will be required to evaluate the safety and efficacy of this therapy, but the early signs are encouraging in terms of the benefits and the low risk of side effects, the authors said.