Long-term metabolic control in recipients of combined pancreas and kidney transplants

Development of islet-like cell clusters after pancreas transplantation in the spontaneously diabetic Torri rat

Pancreas transplantation (PTx) has evolved as a clinical therapy to achieve sustained euglycemia. However, it remains unclear if naive diseased islets of the pancreas benefit from the avoidance of glucose toxicity by PTx. In the present study, using an animal model of type 2 diabetes, the Spontaneously Diabetic Torii (SDT; RT1a) rat, we syngeneically transplanted nondiabetic 10-week-old pancreaticduodenal grafts into diabetic 25-week-old recipients. In the control SDT rats that received no treatment, hyperglycemia developed with a mean onset time of 25 +/- 3.9 weeks of age. Few normal islet cells were found from 25 weeks and none at 40 weeks. However, in the PTx rats, the onset age (graft age) of diabetes was significantly prolonged (47 +/- 18.2 weeks). Moreover, we found that the beta-cell mass was significantly increased in the naive pancreases of 40-week-old PTx recipients (PTx40-naive). Interestingly, islet-like cell clusters of varying size were found close to ductal structures of PTx40-naive pancreases, suggesting that these cells are derived from ductal cells. Furthermore, pancreatic and duodenal homeobox factor-1 (PDX-1) was more clearly expressed in the nuclei of PTx40-naive pancreatic islet-like cell clusters. Our results demonstrate the development of duct-derived beta cells in the pancreas of type 2 diabetic recipients after PTx.

Urological complications of pancreatic transplantation

PURPOSE

Pancreas transplantation is increasingly being used in the treatment of type I insulin-dependent diabetes mellitus. Because bladder drainage of the exocrine pancreatic secretion is the procedure of choice, urological complications are frequent. As the number of these procedures increases the urologist will have an extended role in the management of the postoperative complications, the majority of which are urological.

MATERIALS AND METHODS

The literature from 1985 on the complications related to pancreas transplants was reviewed.

RESULTS

Approximately 50 to 60% of bladder drained pancreas transplant recipients will have a urological complication postoperatively.

CONCLUSIONS

The increasing application of bladder drained pancreas transplantation in the treatment of type I insulin-dependent diabetes mellitus necessitates that the clinical urologist is familiar with the management of complications related to this procedure.

[Benefits and limitations of pancreas transplantation in insulin-dependent diabetics: a study apropos of 26 patients]

From November 1990 to March 1995, 26 simultaneous pancreas-kidney (SPK) transplants were carried out. The recipients were uremic type I diabetic patients. After the first year of transplantation, patient survival was 96% and pancreas and kidney survival was 69% and 84%, respectively. The pancreas transplant failure was due to veinous thrombosis (two cases), and to graft rejection (71%). The most common urologic complications of bladder drainage were urethritis (61%), bicarbonate loss (42%) and urinary tract infections (100%). Fasting blood glucose (0.91 +/- 0.1 g/L), hemoglobin A1C (5.3 +/- 0.4%) and lipidic profile were found to be normal among diabetic recipients whose grafts had been functioning for 1 year. The insulin secretion of type I diabetic patients with SPK transplants (n = 13), and six non diabetic patients with kidney transplants was assessed by oral glucose tolerance tests. Only the patients with SPK transplants presented late hyperinsulinemia at 120 minutes. The quality of life for both type I diabetic patients after SPK transplants and diabetics treated by insulinotherapy (n = 6), was studied. After transplantation, the quality of life improved only because of insulin independence. In spite of chirurgical and urologic complications, pancreas transplantation in type I diabetic patients improves both metabolic control and quality of life.

Pancreas and islet transplantation in man

The results of pancreas transplantation have greatly improved, the overall patient and graft 1-year survival rates now being 89 and 62%, respectively. A technically successful graft ensures a near-normal glucose metabolism in most cases, and improves the patient's quality of life. However, pancreas transplantation is not a life-saving procedure and because of the necessary permanent immunosuppression it is usually performed in patients in whom a kidney transplant is needed or has been previously established. In such patients the other diabetic chronic complications are often advanced and limit the potential benefit of pancreas transplantation, but it seems premature to extend the indications to early stage diabetes. Islet transplantation has many potential advantages, mainly the possibilities of immune alteration and immune protection of the transplant that could allow transplantation to be performed without immunosuppression and the use of xenogenic tissue. Major limiting factors are the high numbers of islets necessary to ensure insulin independence and the low yield of islet isolation from adult pancreas. Encouraging, albeit preliminary results have been recently reported in man.