Islet Cell Advances May Fight Diabetes
New Technique in Islet Cell Transplantation Uses Ultrasound Technology
Nov. 29, 2005 -- An advance in an experimental treatment that promotes
natural insulin production among people with type 1 diabetes may mean that more
patients will one day be able to live without daily insulin injections.
Researchers used ultrasound guidance to help them inject and transplant
insulin-producing cells, known as beta-islet cells, into the liver. They also
developed a technique that appears to lower the risk of bleeding complications
associated with the procedure.
Their islet-transplantation technique is minimally invasive and could
potentially be done as a same-day procedure, says researcher Saravanan
Krishnamoorthy presented the findings in Chicago at RSNA 2005, the annual
meeting of the Radiological Society of North America.
"There are still problems that have to be addressed, but this could be
done as an outpatient procedure," he tells WebMD.
Although still experimental, islet-cell transplantation offers the promise
of helping large numbers of people with type 1 diabetes lead more normal
People with this type of diabetes produce little or no insulin, the hormone
that helps cells break down glucose (sugar) in the blood for fuel. This is due
to the body's destruction of the islet cells that make insulin. Islet cells are
found in the pancreas.
has been traditionally known as "juvenile"
diabetes and requires lifelong insulin supplementation.
The transplantation of beta-islet cells from donor pancreases has been shown
to promote natural insulin production among patients. But like other transplant
patients, islet recipients must take powerful immune-suppressing drugs to
prevent rejection of the foreign cells.
About 400 patients worldwide had received islet cell transplants from donor
pancreases as of late last year, with varying degrees of success.
The study reported by Krishnamoorthy and colleagues at the University of
Minnesota, Minneapolis included 13 patients with poorly controlled type 1
The researchers used ultrasound technology to locate the best site for islet
cell infusion. They were able to transplant cells on the first attempt in
two-thirds of cases and were successful on the second attempt in most other
They also used a specialized technique to help prevent bleeding
complications from the needle used to inject the cells.
No major complications or deaths were reported among the patients, who were
followed for a month after receiving the islet cells. All 13 were producing
insulin on their own. Transplant recipients had some reported anemia (lower
blood count) and abnormal liver enzyme levels.
American Diabetes Association spokesman Nathaniel Clark, MD, says islet cell
transplantation is a promising technique for the treatment of type 1 diabetes.
But he adds that some major hurdles remain for the therapy.
Rejection of transplanted cells remains a big problem, and the long-term
side effects of currently available antirejection drugs are poorly understood.
But better antirejection drug protocols are helping to improve long-term
results and minimize the risks to patients.
Researchers are also working to develop methods of transplanting islet cells
that will reduce or eliminate the risk of rejection. One approach involves
coating islet cells with a gel that prevents the immune system from attacking
Collecting enough islet cells to transplant is also a major problem. Two
donor pancreases are currently needed to provide the number of islet cells used
for a single transplant.
Researchers are investigating whether islet cells from pigs are suitable for
human transplant. And human embryonic stem cells could potentially produce
suitable cells for transplant.
Despite the hurdles, Clark says islet transplantation has the potential to
transform the treatment of type 1 diabetes.
"This continues to be one of the most exciting and promising techniques
to potentially produce a cure for this disease," he says.