Comparison of azathioprine and mycophenolate mofetil in pancreas transplantation

Results of pancreas transplantation after steroid withdrawal under tacrolimus immunosuppression

PURPOSE

The results of steroid withdrawal in pancreas transplant recipients under tacrolimus immunosuppression were analyzed.

METHODS

From July 4, 1994 until April 30, 1998, 147 pancreas transplantations were performed in 141 patients, including 126 simultaneous pancreas-kidney transplantations, 13 pancreas after kidney transplantation, and 8 pancreas transplantations alone. Baseline immunosuppression consisted of tacrolimus and steroids without antilymphocyte induction. Twenty-three patients were excluded from analysis because of early graft loss in 17 cases, retransplantation in 5 cases, and simultaneous pancreas-kidney transplantation after heart transplantation in 1 patient.

RESULTS

With a mean follow-up of 2.8+/-1.1 years (range 1.0 to 4.8 years), complete steroid withdrawal was achieved in 58 (47%) patients with a mean time to steroid withdrawal of 15.2+/-8 months (range 4 to 40 months after transplantation). Of the entire cohort of 141 patients, overall 1-, 2-, and 4-year patient survival rates were 98%, 95.5%, and 86%, respectively. Overall 1-, 2-, and 4-year graft survival rates were 83%, 80%, and 71% (pancreas) and 95%, 91%, and 84% (kidney), respectively. Of the 124 patients analyzed for steroid withdrawal, 1-, 2-, and 4-year patient survival rates were 98%, 97%, and 92%, respectively. Overall 1-, 2-, and 4-year graft survival rates were 98%, 91.5%, 83% (pancreas) and 97%, 95%, and 91% (kidney). Patient, pancreas, and kidney survival rates at 1 year were 100%, 100%, and 98% (off steroids) versus 97%, 91%, and 96% (on steroids, all NS) and at 4 years were 100%, 94%, and 95% (off steroids) versus 78%, 68%, and 85% (on steroids, P = 0.01, 0.002, and NS, respectively). The cumulative risk of rejection at the time of follow-up was 76% for patients on steroids versus 74% for patients off steroids (P = NS). Seven patients originally tapered off steroids were treated for subsequent rejection episodes, which were all steroid sensitive, and two of these seven patients are currently off steroids. Thirteen patients received antilymphocyte therapy for steroid-resistant rejection, five of whom are now off steroids. Tacrolimus trough levels were 9.3+/-2.4 ng/ml (off steroids) and 9.7+/-4.3 (on steroids, P = NS). Mean fasting glucose levels were 98+/-34 mg/dl (off steroids) and 110+/-41 mg/dl (on steroids, P = NS). Mean glycosylated hemoglobin levels were 5.2+/-0.9% (off steroids) and 6.2+/-2.1% (on steroids, P = 0.02), and mean serum creatinine levels were 1.4+/-0.8 mg/dl (off steroids) and 1.7+/-1.0 mg/dl (on steroids, P = 0.02).

CONCLUSION

These data show for the first time that steroid withdrawal can be safely accomplished in pancreas transplant recipients maintained on tacrolimus-based immunosuppression. Steroid withdrawal is associated with excellent patient and graft survival with no increase in the cumulative risk of rejection.

Vascularized pancreas allotransplantation--clinical indications and outcome

AIMS

This review examines the status of vascularized pancreas transplantation as a treatment for Type 1 diabetes mellitus (DM).

METHODS

The world literature, with a particular emphasis on data from the International Pancreas Transplant Registry (IPTR), is reviewed and interpreted particularly for clinical indications and outcome.

RESULTS

Over 9000 cases of vascularized pancreas transplant (VPT) have been registered, with insulin dependence approaching 82% at 1 year with 94% patient survival. The majority of transplants are simultaneous pancreas and kidney (SPK) transplants, with far fewer pancreas after kidney (PAK) or pancreas transplants alone (PTA). The success rates differ between the procedures but are generally improving as technical advances, improvements in immunosupression and greater experience are gained. The most obvious advantage is an improved quality of life (QoL) but there are risks associated with the procedure and with the immunosuppression. There is some evidence coming to light of a very slow beneficial effect on microvascular complications.

CONCLUSIONS

VPT is an attractive option to offer Type 1 DM patients who need or already have a renal allograft. Patients have to decide between the increased surgical risk and the risks of long-term immunosuppression and the benefits of improved QoL. In the absense of end-stage renal failure (ESRF) there is no justification for PTA, except where the diabetes itself poses a greater risk to life than the transplantation procedure.

Long-term results of pancreas transplantation under tacrolius immunosuppression

BACKGROUND

The long-term safety and efficacy of tacrolimus in pancreas transplantation has not yet been demonstrated. The observation of prolonged pancreatic graft function under tacrolimus would indicate that any potential islet toxicity is short-lived and clinically insignificant. We report herein the results of pancreas transplantation in patients receiving primary tacrolimus immunosuppression for a minimum of 2 years.

METHODS

From July 4, 1994 until April 18, 1996, 60 patients received either simultaneous pancreas-kidney transplant (n=55), pancreas transplant only (n=4), or pancreas after kidney transplantation (n=1). Baseline immunosuppression consisted of tacrolimus and steroids without antilymphocyte induction. Azathioprine was used as a third agent in 51 patients and mycophenolate mofetil in 9. Rejection episodes within the first 6 months occurred in 48 (80%) patients and were treated with high-dose corticosteroids. Antilymphocyte antibody was required in eight (13%) patients with steroid-resistant rejection.

RESULTS

With a mean follow-up of 35.1+/-5.9 months (range: 24.3-45.7 months), 6-month and 1-, 2-, and 33-year graft survival is 88%, 82%, 80%, and 80% (pancreas) and 98%, 96%, 93%, and 91% (kidney), respectively. Six-month and 1-, 2-, and 3-year patient survival is 100%, 98%, 98%, and 96.5%. Mean fasting glucose is 91.6+/-13.8 mg/dl, and mean glycosylated hemoglobin is 5.1+/-0.7% (normal range: 4.3-6.1%). Mean tacrolimus dose is 6.5+/-2.6 mg/day and mean prednisone dose 2.0+/-2.9 mg/day at follow-up. Complete steroid withdrawal was possible in 31 (65%) of the 48 patients with functioning pancreases.

CONCLUSIONS

These data show for the first time that tacrolimus is a safe and effective long-term primary agent in pancreas transplantation and provides excellent long-term islet function without evidence of toxicity while permitting steroid withdrawal in the majority of patients.