Miami, FL (August 27, 2002) — Scientists at the Diabetes Research Institute have successfully transplanted cultured islet cells into nine consecutive diabetic patients and achieved insulin-independence in all nine.
The proven ability to isolate and maintain transplant-quality islets for this extended period of time means that diabetic patients that do not necessarily live near islet isolation centers now have as good a chance of being transplanted with the insulin-producing cells as those living nearby. The encouraging results involving this experimental procedure are being presented Tuesday, August 27th, at the XIX International Congress of The Transplantation Society in Miami, Florida.
“With this procedure we have been able to widen the window of time during which islets can be transplanted, and make it easier for patients to get to the specialized centers where this type of procedure is available,” explains Rodolfo Alejandro, M.D., Professor of Medicine at the University of Miami School of Medicine and Director of the Clinical Islet Transplant Program at the Diabetes Research Institute, where the trial was conducted.
“The additional time also lets us better assess the cells that we are transplanting to determine their survivability and potency, as well as administer the pre-operative medications we have to give patients who are receiving the transplant.”
Until now, previous trials had suggested that the insulin-producing cells that are destroyed when patients develop Type 1 diabetes had to be transplanted immediately after being harvested from donor pancreases in order to function. This restriction posed many time and logistical limitations for both physicians and patients alike, some of who had to travel long distances in order to receive their transplanted cells.
These recent results, however, clearly demonstrate that clinical islets can be carefully nurtured and kept in culture anywhere from several hours to several days, prior to their infusion. The additional time opens up the therapy to those who live in more remote areas of the US and also allows prospective patients more time for immunosuppression regimens to be completed pre-operatively, an important component in this successful strategy.
In this trial, the DRI team successfully transplanted patients from as far away as Alaska and California, and has recently shipped cultured islets to Texas for that state’s first successful cases (4) of islet cell transplantation.
“We consider these results extremely encouraging for what they represent on the broader scale, that this procedure can be offered to many more people than before,” explains Camillo Ricordi, M.D., Scientific Director of the Diabetes Research Institute at the University of Miami. “This is the first trial in the US to obtain insulin-independence in 9 of 9 consecutive patients receiving transplanted islet cells that have been cultured prior to infusion, under a new regimen of immunosuppressive drugs.”
Participation in this trial required that patients with Type 1 diabetes meet strict eligibility criteria, including having a history of hypoglycemic unawareness — an incapacitating symptom characterized by the inability to detect the early warning signs of dangerously low drops in blood sugar. It is a patient’s ability to recognize the life-threatening signs that accompany hypoglycemia such as dizziness, confusion, tremor, and disorientation that enable him to act quickly and seek assistance, eat something to raise his blood sugar level, or pull his or her car over to the shoulder when driving.
All patients reported drastic and significant improvements in their quality of their lives after the transplants.
The study protocol involves isolating the delicate insulin-producing cells from a donor pancreas using a modified version of the Ricordi method, named after its inventor and DRI Director, Camillo Ricordi. Islets are then cultured for a period ranging from hours to days (range 7-64 hours), during which time they are assessed for potency and viability. In the interim, patients are treated pre-operatively with an induction agent, daclizumab, intended to lower the body’s natural immune response and facilitate the transplant’s success.
The protocol calls for two infusions of islet cells several days apart, followed by an anti-rejection maintenance regimen consisting of Sirolimus/Tacrolimus, drugs previously successful in stemming the rejection of transplanted tissues.
All 9 patients achieved immediate insulin independence after the second infusion of islets, achieved metabolic control with blood sugar levels well within the normal range, and did not experience episodes of hypoglycemic unawareness. While two of the patients have recently been put on small amounts of insulin after having been off for 208 and 356 days, respectively, they too have quantifiable improvements in their metabolic control. The study’s first patients have been off insulin for more than a year and there are more patients rapidly approaching that mark. Additional patients are already listed and eagerly awaiting their turn for new protocols about to open.
“Progress in research is always a matter of steps,” adds Dr. Alejandro, “This study, although small, tells us that life without insulin is now a real possibility for many more patients, even for those who yesterday thought they lived too far away from centers like the DRI to entertain the thought.”
Mitra Zehtab, MD, MBA