Correspondence

Pancreatic and Islet Transplantation for Diabetes

N Engl J Med 1993; 328:1496-1497May 20, 1993

Article

To the Editor:

Robertson (Dec. 24 issue)1 contends that pancreatic transplantation should no longer be considered an experimental procedure. I do not understand how he can reach this conclusion, when the proper use and results of pancreatic transplantation remain in question. Other less complicated transplantation procedures, such as allogeneic and autologous bone marrow transplantation, are considered experimental for some diseases because of the lack of efficacy and the unacceptable morbidity and mortality associated with the therapy that accompanies these procedures. Technical success in transplanting the graft is not the sole determinant of whether a procedure should no longer be considered experimental.

Robertson states that “recipients of successful pancreatic allografts report . . . greater overall satisfaction with their lives,” but does not describe or define what constitutes success. Consider the patient who has a functioning graft, but who is having complications from the procedure or immunosuppressive therapy (or both) and who requires frequent physician visits and hospitalizations. Does this result constitute success?

Joseph J. Mazza, M.D.
Marshfield Clinic, Marshfield, WI 54449

1 References

1. 1

   Robertson RP. Pancreatic and islet transplantation for diabetes -- cures or curiosities? N Engl J Med 1992;327:1861-1868
   Full Text | Web of Science | Medline

To the Editor:

Robertson states “there is currently no shortage of pancreases from cadaveric donors.” As with other transplanted organs, there is a critical shortage of pancreases throughout the country. The author may have been misled by statistics showing that very few pancreases are obtained from cadaveric donors. He may therefore have assumed that many donor organs are available. Unfortunately, the strict criteria for pancreatic transplantation preclude obtaining most potentially available organs. If islet transplantation becomes a reality, current estimates are that five to eight donors will be required to obtain enough islets for a single recipient.

The overall waiting list for cadaveric organs contains more than 26,000 names and is growing by 15 to 20 percent per year. In my own practice many candidates for combined cadaveric renal-pancreatic transplantation will eventually receive kidney transplants from living related donors instead because of the severe shortage of cadaveric organs.

Jonathan S. Bromberg, M.D., Ph.D.
Medical University of South Carolina, Charleston, SC 29425

Author/Editor Response

Dr. Robertson replies:

To the Editor: The letters from Dr. Mazza and Dr. Bromberg raise important questions: Is pancreatic transplantation still experimental? What are the criteria for successful pancreatic transplantation? Is there a shortage of pancreases suitable for transplantation?

The operative procedure itself is no longer experimental because it has reached a developmental plateau and is roughly as successful in terms of organ survival as other organ transplantations. As I pointed out in my article, however, the application of this operation remains controversial -- i.e., when is it justifiable and appropriate in terms of costs and benefits for patients?

The criterion for successful pancreatic transplantation is maintenance of normal glucose levels without insulin treatment. Although the complications of immunosuppressive therapy are serious, they do not in themselves negate the success and benefits of a functioning pancreatic transplant any more than they negate the success and benefits of a functioning kidney transplant. Obviously, this is not an issue if the potential recipient of a pancreas is already scheduled for kidney transplantation and immunosuppression.

There is no current shortage of transplantable pancreases. Of the more than 4500 cadaveric donors in the United States last year, 4000 could potentially have provided pancreases suitable for transplantation (Sutherland D: personal communication). Even if all diabetics who receive a kidney transplant (roughly 2500 each year) also receive a pancreas, that leaves 1500 organs available each year for other diabetic patients without azotemia whose metabolic problems are severe enough to warrant pancreatic transplantation. This is more than enough.

Successful islet transplantation does not require five to eight donors. Reports from the University of Minnesota in the past year indicate that 250,000 to 750,000 islets (one fourth to three fourths of a pancreas) are sufficient to maintain normal glucose levels without exogenous insulin in recipients of islet autografts1 and allografts2.

R. Paul Robertson, M.D.
University of Minnesota, Minneapolis, MN 55455

2 References

1. 1

   Pyzdrowski KL, Kendall DM, Halter JB, Nakhleh RE, Sutherland DER, Robertson RP. Preserved insulin secretion and insulin independence in recipients of islet autografts. N Engl J Med 1992;327:220-226
   Full Text | Web of Science | Medline

2. 2

   Gores PF, Najarian JS, Stephanian E, Lloveras JJ, Kelley SL, Sutherland DER. Insulin independence in type I diabetes after transplantation of unpurified islets from single donor with 15-deoxyspergualin. Lancet 1993;341:19-21
   CrossRef | Web of Science | Medline