Thursday, June 12, 2008

UIC Improves Islet Transplants, How Long Will Insulin Indepencence Last?

A somewhat important news development which was largely overlooked due to its poor timing (overlapping with the end of the ADA Scientific Sessions), the June 2008 issue of the American Journal of Transplantation featured the results of an important advancement in islet transplantation.

To date, one of the main issues limiting progress in islet cell transplantation has been limited by the severe shortage of donor organs, said Dr. José Oberholzer, who is the director of cell and pancreas transplantation and lead author of the study, and also associate professor of surgery, bioengineering and endocrinology at University of Illinois at Chicago (UIC).

UIC is one of only seven federally funded National Institutes of Health Islet Cell Resource Centers across the country that provides researchers with human pancreatic islet cells for transplantation into diabetic patients and for basic science research on diabetes. But UIC is one of only a few centers worldwide that have been able to achieve reproducible and consistent insulin independence in "severe" type 1 diabetes patients (meaning the patients suffered from severe metabolic instability characterized by sudden, frequent hypoglycemia without symptoms).

UIC researchers have slightly modified the Edmonton Protocol procedure for islet cell transplantation and achieved insulin independence in diabetes patients with fewer but better-functioning pancreatic islet cells.

"This study is extremely promising and shows that we can achieve success with fewer islet cells, freeing patients from the need to check their insulin, even after 20 or 30 years of suffering from diabetes," Dr. Oberholzer said.

What did they do differently from the widely-tested Edmonton Protocol? Six patients received the slightly-modified UIC protocol -- which was a combination of etanercept (an anti-inflammatory drug developed to treat rheumatoid arthritis) plus the inclusion of exenatide (a drug approved for use in type 2 diabetes, better known as BYETTA) -- in addition to the Edmonton regimen. The new procedure allowed patients to get off insulin with only a single transplant versus the two to four transplants that were needed using the older protocol, said Oberholzer.

By comparison, the four patients who received the standard Edmonton protocol needed either two or three sequential islet cell transplants to achieve insulin-independence. The six patients who were treated using the UIC protocol initially achieved insulin-independence after only one islet transplant. Two of these patients required a second islet cell transplant, and one resumed insulin five months after the second transplant due to other complications.

The bigger question is how long will their insulin-independence last? Many people have attained insulin independence with islet transplants, only to see that last for only a year or two at most. The big difference with the UIC Protocol is the addition of BYETTA, which is largely viewed as a Type 2 diabetes drug, but one which also encourages the transplanted beta cells to replicate themselves, thus potentially enabling the newly transplanted cells to replicate and possibly extending their insulin-independence. Last year at the ADA Scientific Sessions in Chicago, researchers with the Diabetes Research Institute showed that including exenatide prolonged insulin independence. Now, the key will be to watch the follow-ups on patients receiving transplants with the UIC Protocol to determine how much longer insulin independence is sustained with the new protocol. Only time will tell!

2 comments:

BetterCell said...

Immunosuppressive drugs that have to be taken with any beta cell transplants are highly toxic creating problems of their own such as the possible creation within the Host to various infections as well as the possible risk if the dreaded MRSA.
That along with the current Life span of "Diabetes-Free" 0-5 years, is not worth it. The Risk-Benefit ratio do not give good odds at the present time.
It is a crap-shoot..........
and yes, I remain an *Optimist*.

Scott said...

I generally agree; I haven't yet reached the point where I believe that immunosuppression is worth the severe cost, especially with a limited benefit in terms of insulin independence. But there are some who believe that their lives were much better with immunosuppression and that the side-effects were not nearly as bad as some claim them to be. Deb Butterfield is one such person.

My own perspective is that the continued fixation on glycemic control above all else is robbing patients of comprehensive care which also needs to include quality of life elements, and statistical probability assessments of likelihood of developing certain "complications", some of which are now known to have absolutely nothing to do with glycemic control (cardiovascular disease, in particular; in type 1, there is evidence that it too is caused by an autoimmune response, whereas in type 2, it is due more to the elements normally associated with cardiovascular disease), furthermore, some types of neuropathy are also known to have a similar etiology. The bottom line for me is that while progress should be encouraged, there is a widespread assumption that diabetes itself is responsible for any possible ailment which a patient can develop, even though this assumption is not supported by sound science. For that reason, I believe the FDA is making a huge mistake by designating HbA1c as a "surrogate" for patient outcomes, but for whatever reason, the medical profession has remained silent barring a few people from the Mayo Clinic who continue to call attention to this issue.