Simultaneous pancreas-kidney transplantation at the University of Pittsburgh

Analysis of the SPK program at the University of Pittsburgh has led to a number of observations: 1. Under tacrolimus-based immunosuppression, without antibody induction, it has been possible to achieve (a) One- and 3-year actuarial patient survival rates of 98% and 95% (b) One- and 3-year actuarial kidney survival rates of 95% and 87% (c) One- and 3-year actuarial pancreas survival rates of 86% and 80% 2. Steroid withdrawal has been achieved in over half of the successfully transplanted recipients, with excellent outcomes and a low rate (4.7%) of subsequent rejection. 3. Bone marrow augmentation has been associated with (a) less rejection (b) less pancreatic graft loss to rejection (c) an increased ability to withdraw steroids 4. Rejection has been associated with a rising serum lipase. 5. Renal allograft rejection in SPK patients with elevated serum lipase levels has been seen in the setting of normal renal function. 6. Enteric drainage has been associated with a reasonably low complication rate. 7. SPK transplantation is a successful therapeutic option in selected type I diabetics with end-stage renal disease.

Kidney transplantation for end-stage renal failure in liver transplant recipients with hepatitis C viral infection

BACKGROUND

End-stage renal failure after successful liver transplantation (LTx) has been described in up to 5% of patients. Kidney transplantation (KTx) has been the treatment of choice in these cases. However, in recipients infected with hepatitis C virus (HCV), the augmentation of immunosuppression after KTx may result in an increased viral load. This, in turn, may adversely affect the liver allograft.

METHOD

The present study retrospectively examined the outcome in 17 patients (3 females and 14 males, mean age 51.1+/-11.3 years) who received KTx after LTx. The mean interval from LTx to KTx was 57.6+/-32.1 months. The mean follow-up was 41.7+/-20.5 months after KTx, and 99.6+/-37.7 months after LTx. Sixteen of the 17 patients received tacrolimus-based immunosuppression at the time of KTx.

RESULTS

During the follow-up period, one patient underwent combined liver and kidney retransplantation 3.7 years after KTx and 12.7 years after LTx. She subsequently died secondary to primary nonfunction. Four other patients died, two of lung cancer, one of pancreatitis/sepsis, and one of severe depression leading to noncompliance. A total of 29 episodes of biopsy-proven acute renal allograft rejection (1.7 episodes/ patient) were encountered and treated with steroids. Seven patients experienced a rise in liver function tests during the period of increased steroid dosage. Four patients received no treatment, and their liver function returned to baseline. The remaining three were treated with interferon. Overall 1- and 3-year actuarial patient and liver allograft survival was 88% and 71% (after renal transplantation); corresponding 1- and 3-year actuarial graft survival was 88% and 61%. Twelve patients are alive with normal liver function. One patient is on dialysis, because of renal allograft loss to noncompliance.

CONCLUSION

In this series, LTx recipients with HCV infection were able to undergo KTx with a reasonable degree of success. KTx should be offered for end-stage renal failure after LTx, even in the presence of HCV infection, to individuals with stable liver function and no signs of liver failure.

Occult nonhematopoietic malignancies present at autopsy in solid organ transplant patients who died within 100 days

BACKGROUND

Patients are at an increased risk for developing malignancies after transplantation. Lymphomas, skin malignancies, Kaposi's sarcomas, and cervical/vulvar neoplasms are the most common, but visceral malignancies are also well documented, with a reported frequency ranging from 1% to 6%. These visceral tumors represent a mix of neoplasms that were clinically occult at the time of transplantation and those that arise de novo after transplantation. Little information, however, is available on the frequency of clinically occult malignancies at the time of transplantation and their contribution to the number of posttransplant malignancies.

METHODS

A retrospective study was performed of all patients who received an organ transplant from January 1981 to June 1997 and died within 100 days, a time interval in which epithelial malignancies found at autopsy were presumed to have been present, but clinically occult, at the time of transplantation.

RESULTS

A total of 375 patients were studied who received the following organ transplants: 231 liver, 52 heart, 26 heart and lung, 32 lung, and 34 kidney. Eleven malignancies were identified for an overall frequency of 2.9% and included three thyroid carcinomas, three carcinoids of the small bowel, two lung carcinomas, one laryngeal carcinoma, one renal cell carcinoma, and one seminoma.

CONCLUSION

The 2.9% frequency of malignancies seen in this study suggests that a small, but significant, number of patients have occult malignancies at the time of transplantation and that these occult tumors contribute substantially to the number of malignancies that present clinically after transplantation.

Immunomodulation for intestinal transplantation by allograft irradiation, adjunct donor bone marrow infusion, or both

BACKGROUND

The passenger leukocytes in the intestine have a lineage profile that predisposes to graft-versus-host disease (GVHD) in some animal models and have inferior tolerogenic qualities compared with the leukocytes in the liver, other solid organs, and bone marrow. Elimination by ex vivo irradiation of mature lymphoid elements from the bowel allografts is known to eliminate the GVHD risk. We hypothesized that infusion of donor bone marrow cells (BMC) in recipients of irradiated intestine would improve tolerogenesis without increasing the risk of GVHD.

METHODS

Orthotopic small intestine transplantation was performed with the GVHD-prone Lewis (LEW)-to-Brown Norway (BN) combination and the reverse GVHD-resistant BN-to-LEW model under a short course of tacrolimus treatment (1 mg/kg/day, days 0-13, 20, 27). Grafts were irradiated ex vivo, using a 137Cs source. In selected experimental groups, donor BMC (2.5 x 10(8)) were infused on the day of small intestine transplantation.

RESULTS

The unmodified LEW intestine remained intact, whether transplanted alone or with adjunct donor BMC infusion, but all of the BN recipients died of GVHD after approximately 2 months. Intestinal graft irradiation (10 Gy) effectively prevented the GVHD and prolonged survival to 92.5 days, but all of the BN recipients died with chronic rejection of the LEW grafts, which was prevented by infusion of adjunct donor BMC without causing GVHD. In the GVHD-resistant reverse strain direction (BN-->LEW), all intestinal recipients treated for 27 days with tacrolimus survived > or =150 days without regard for graft irradiation or adjunct BMC, but chronic rejection was severe in the irradiated intestine, moderate in the unaltered graft, and least in the irradiated intestine transplanted with adjunct BMC. Mild arteritis in the 150 day allografts of both strain combinations (i.e., LEW--> BN and BN-->LEW) may have been irradiation associated, but this was prevented when weekly doses of tacrolimus were continued for the duration of the experiment rather than being stopped at 27 days.

CONCLUSIONS

Recipients are protected from GVHD by irradiating intestinal allografts, but the resulting leukocyte depletion leads to chronic rejection of the transplanted bowel. The chronic rejection is prevented with adjunct donor BMC without causing GVHD. Although application of the strategy may be limited by the possibility of radiation injury, the results are consistent with the paradigm that we have proposed to explain organ-induced graft acceptance, tolerance, and chronic rejection.