2012年1月16日 星期一

Stem cells could offer a future free from insulin injections

'Re-training' immune cells in people with type 1 diabetes reduces the amount of insulin they need to inject, according to a results from a small clinical trial.

The team, led by Dr Yong Zhao of the University of Illinois, USA, used stem cells from the cord blood of healthy donors to 're-educate' patients' faulty immune cells.

'They wake them up and correct their function. The stems cells are like a teacher. The [immune] cells are like a bad student', Dr Zhao explained to the Toronto Star. 'The patients couldn't make any insulin before the treatment. But after the treatment they began to make their own insulin'.

Type 1 diabetes is caused by the patient's own immune system attacking cells in the pancreas that produce insulin. The resulting decrease in insulin production affects the regulation of sugar levels in the blood and may cause organ damage and premature death. Patients must inject insulin on a daily basis to balance their blood glucose level.

The team recruited 15 people with type 1 diabetes from the Jinan Central Hospital in China, with 12 receiving the treatment and the other three making up a control group. The treatment, known as Stem Cell Educator therapy, passes a patient's immune cells over stem cells from a healthy donor for three hours, before putting them back into the patient's bloodstream.

All the patients who received the therapy had higher levels of c-peptide, a by-product of insulin production, 12 weeks after treatment, indicating improved pancreatic cell function. Levels had increased again by 24 weeks, and this increase was maintained at 40 weeks post-treatment.

At the start of the study, six subjects were assessed as having severe diabetes, producing almost no insulin, and six who produced more, but still insufficient amounts of insulin as having moderate diabetes. The results, published in the journal BMC Medicine, showed that the required insulin dose decreased by an average of 38 percent in those with moderate diabetes and 25 percent in those with severe diabetes.

Dr Zhao and his group intend to conduct further trials, with subjects receiving more than one treatment, with the ultimate hope of a future where patients no longer require insulin injections. They are also expanding this research to other autoimmune disorders, and are beginning a clinical trial in people with type 2 diabetes, where the pancreas does produce enough insulin, but liver cells stop responding properly.

Source: BioNews (16th January, 2012)