Reported April 13, 2011
Curing Diabetes -- Research Summary
BACKGROUND: Type 1 diabetes is an autoimmune disease in which the body's immune system attacks and destroys insulin-producing cells. Patients with type 1 diabetes must take insulin daily to live. However, there is a new treatment option for patients with type 1 diabetes called islet transplantation.
THE TREATMENT: Islet cells make up 1-2 percent of the pancreas and are responsible for insulin production. In islet transplantation, islet cells are taken from a deceased donor's pancreas and injected into the patient's liver via a catheter. The patient usually receives 10,000 islet equivalents per kilogram of body weight, an amount, which usually requires two donors. After the transplant, the patient must take immunosuppressive drugs, or anti-rejection drugs. These drugs prevent the patient’s immune system from recognizing the new islet cells as foreign (SOURCE: diabetes.niddk.nih.gov).
Ideally, after islet transplantation, the patient will be able to control blood glucose levels without regular injections of insulin; effectively, they will be cured of type 1 diabetes. In the University of Alberta’s 2005 follow up study of patients who had undergone islet transplantation in 2000, ten percent of the 65 patients remained “insulin independent” five years after the transplant. Though most of the patients did return to insulin injections, researchers found that many of them were able to decrease the amount of insulin they needed (SOURCE: diabetes.niddk.nih.gov).
DRAWBACKS: Islet transplantation still has a number of obstacles to overcome before it becomes widespread. One of the major problems with islet transplantation is a lack of islets. Even though about 7,000 people donate their organs every year in the U.S., fewer than half of the donated pancreases are suitable for the harvesting of islets. With most islet transplants requiring islets from two different donors, this makes islet transplants available for a very small fraction of the people with type 1 diabetes. However, researchers are working on ways to circumvent the problem by transplanting islet cells from living donors, animals such as pigs or monkeys, or creating islet cells out of stem cells (SOURCE: diabetes.niddk.nih.gov). MORE (see below please)
FOR MORE INFORMATION, PLEASE CONTACT:
Amer Rajab, M.D., Ph.D.
The Ohio State University
Columbus, OH
Amer.Rajab@osumc.edu
Curing Diabetes -- Research Summary | Medical News and Health Information
Reported April 13, 2011
Curing Diabetes -- In Depth Doctor's Interview
Amer Rajab, M.D., Ph.D., from the Ohio State University, explains how islet cell transplants could revolutionize diabetes treatment.
Something that you just did for the first time is the islet cell transplant.
Dr. Amer Rajab: It is the first time for a diabetic patient. We did it for a different type of indication; we call it chronic pancreatitis, a patient who has inflammation of the pancreas, so we did what we call an auto transplant: we take their pancreas out, extract the cell, the islet, and give it back to the patient. But for a diabetic patient, with type one diabetes, this was our first transplant.
Is this the first step towards curing diabetes?
Dr. Amer Rajab: It may be. In diabetes, the cells that make insulin just stop working completely. So when you have type 1 diabetes, these cells that make the hormone, insulin, which we are all familiar with, stop making any hormone. So when we do a transplant, we're replacing these nonfunctioning or dead cells with a brand new group of cells, that's an islet transplantation. Currently, we at Ohio State do pancreas transplants, we give the patient a whole new organ. That's very successful, but the problem with it is that it's a big operation. It's a three-to-five hour process with significant risk to the patient; it's a very invasive procedure. On the same token, the patient doesn't need the whole pancreas, the patient only needs the cells, the islets. The whole pancreas is like a house with the islet room in it. But the pancreas has nothing to do with diabetes. It helps digest our food, makes enzymes, and for people with diabetes, those parts of the pancreas still work. Only these cells, which constitute just 2 to 5 percent of the whole pancreas-- if the pancreas is about a 100-150 gram organ, we're talking maybe five grams of tissue-- those are the cells that make the insulin. The remaining part, the whole bulk of the pancreas, has nothing to do with diabetes. What we're doing now is giving the patient the whole organ, which is very successful, but the patient doesn't need the whole pancreas, just the islet cells.
And these people who are getting the pancreas, or just the cells, these are very sick people?
Dr. Amer Rajab: I'm sure all of us have someone in their family with diabetes. For me it's not just personal; I see a lot of these patients. When they come to me, they're really sick-- diabetes is such a strong disease; it affects everything in our bodies, and the tragedy is that it affects children. Most cases of type 1 diabetes start in children or young adults. I see patients in their mid-twenties who have had multiple strokes or heart attacks, or who have lost limbs to diabetes. They suffer a lot from diabetes. That's exactly the problem with the pancreas transplant-- some patients can't tolerate the procedure. Basically, we have three different types of diabetes patients. We have the first type, who are doing well with their treatment; they're doing well with insulin shots or pumps, and they can continue with their daily lives. We have, on the other hand, the patients who have so many problems with diabetes, but have developed so many complications that they can't have a pancreas transplant. Islet is a different story, because that's just an injection. The third type are patients with significant sequella from diabetes but they can still go for the whole pancreas transplant, which I would recommend. But the number of diabetes patients is expected to grow, to 1.5 to 2 million patients with type 1 diabetes in the US.
Is that what's called juvenile diabetes?
Dr. Amer Rajab: Correct. It's affecting children or young adults. It does rarely start later than life, but usually it is in younger patients. Type 2 usually comes later than life and is usually associated with obesity.
With transplants you have to have exact matches. Is it harder to get an exact match for these types of cells than it would be for other organs?
Dr. Amer Rajab: In fact, no. It's exactly the same. Like a solid organ transplant, we are going to follow the same steps to cross match so that the recipient won't have antibodies against the donor tissue, and we're going to make sure the donor and recipient have the same blood type. So it is no more than transplanting a whole organ.
Why wouldn't you just always do the islet cell transplant instead of the pancreatic transplant?
Dr. Amer Rajab: Two reasons: first of all, currently the success rate for pancreas transplantation is exceeding the islet cell transplant. So when we talk about transplantation for the pancreas, the ultimate goal for the patient is to come back to normal, to not need insulin. We call that "insulin independent." So there is a chance to be insulin independent. After one year after the pancreas transplant, there is an 80 percent success rate. If the patient gets a pancreas transplant and a kidney transplant at the same time after a kidney failure from diabetes, that number goes up to almost 88 percent, which is very good.
Would you be cured?
Dr. Amer Rajab: Currently, we call that a cure. Of course, the cure is how we can reverse diabetes, how we can get a patient's own cells to recover. But now, if you have an organ that's not working and I give you a new organ, that constitutes a cure. The only problem is that these cells are not your own cells, and your body may reject them and we have to control that immune system response.
So what's the success rate for the islet cell transplant?
Dr. Amer Rajab: Right now it's showing a 20 to 65 percent success rate. So 65 percent of patients were still insulin independent a year later. So you can compare 65 percent to more than 80 percent.
Why is that?
Dr. Amer Rajab: Two reasons: one, when we are isolating the islets, we don't get all the islets; when we separate the islets from the whole pancreas, we lose some. So some patients need more than one infusion to reach the number they need. The second thing is that some of the islets may be damaged; we're exposing them to some pretty significant stress. The third thing is we're still using leftover organs. When I have patients on the waiting list for pancreas transplants, and I have an optimal organ, I can't justify taking that organ and using it for research. So with islet, we are using the leftover organs. Of course, I can use them because for a pancreas transplant I want a whole organ, but with the islet transplant, I'm going to break the pancreas to pieces. I'm going to dissect it, extract the cell, and infuse the cells into the patient. So the quality of the organ is not important to me as long as I know the islets are still functioning. After the whole process, there's still a lot of quality testing before it's released to the recipient. So coming back, we have a limited number of organs; we depend on the generosity of diseased donor families, and that's what we are using, we're using diseased donors. So the optimum organs go to pancreas transplants, and what's left over we use for islets. They're not damaged goods, not at all, but for example, if I have a trauma donor with a little damage to the pancreas, I won't be able to use it for a pancreas transplant because of the risk of leaking or bleeding, but for islet, I'm already going to cut it into small pieces to get the cell. If any part of the pancreas is damaged but the islets are still working, I can use it for islet transplants, but not for a pancreas transplant.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
If you would like more information, please contact:
Amer Rajab, M.D., Ph.D.
The Ohio State University
Columbus, OH
Amer.Rajab@osumc.edu
To read the full report, Curing Diabetes, click here:
Curing Diabetes -- In Depth Doctor's Interview | Medical News and Health Information
International Journal for Equity in Health
Hace 21 horas
No hay comentarios:
Publicar un comentario