Stem cell implants could reverse Type 1 diabetes
New treatment has potential to eliminate need for insulin, lead investigator says
Ten British Columbians with Type 1 diabetes will be surgically implanted with stem cells that are coaxed into behaving like true insulin-producing pancreatic cells in hopes of reversing their disease.
The first patient to receive the implants is keen to exchange his regime of daily pinprick blood tests and insulin injections for a “handful” of pills for immune suppression.
“My blood sugar can go down all day without my noticing, so I’m always at risk for passing out, among other health problems,” said Joshua Robertson. “The risks of immune suppression (medication) are well known and it’s no comparison.”
The trial builds on a procedure that successfully cured mice with diabetes, pioneered by Timothy Kieffer at the University of B.C. After receiving implants of millions of stem cells, the mice were weaned from insulin over several months.
Lead investigator, UBC endocrinologist David Thompson called the new treatment the most promising he has ever worked on.
“If the goal is to allow people to stop taking insulin, this trial has the potential to do it,” he said.
Robertson was implanted last month with several packets smaller than a credit card, each containing millions of immature pancreatic cells, grown from embryonic stem cells using a technique developed by the San Diego biotech firm ViaCyte.
UBC and Vancouver Coastal Health are running the two-year trial supported by a $500,000 grant from Stem Cell Network of Canada.
If the cells multiply and develop as hoped, they will produce insulin in response to the glucose in the blood, reducing or eliminating the need for insulin injections.
“Most people with Type 1 diabetes are taking four or five shots of insulin a day or using a pump, and despite their best efforts, they have wide swings in blood sugar and hypoglycemia,” Thompson said. “If the cells made enough insulin that they could go to one shot (per day) and not have those swings, that would be a significant improvement.”
Existing pancreatic cell implant treatments can reduce the need for insulin shots in many patients.
“If even more insulin is made it may be enough to completely eliminate the need for insulin injections,” he said. Based on the success of the technique on rodents, “it is reasonable to assume that this might happen.”
Type 1 diabetes — known as juvenile diabetes or insulin-dependent diabetes — is an autoimmune disease in which a person’s immune system kills insulin-producing cells in the pancreas. Without insulin, people are prone to coma, blindness, stroke and damage to nerves and organs.
About 10 per cent of diabetics are Type 1 and its management can require frequent injections and pinprick blood tests to monitor glucose levels.
Researchers hope the new technique will overcome some of the limitations of pancreatic islet cell transplants, which require a lifetime of anti-rejection drugs to stop the body from destroying the implanted cells. While 1,000 patients have received islet cell implants, the so-called Edmonton Protocol uses tissue harvested from organ donors upon their death, so suitable cells are in chronic short supply.
Because stem cells can be grown in a lab, the supply of cells for the new treatment is essentially “limitless,” Thompson said.