Single centre experience with mycophenolate mofetil for refractory rejection in cadaveric renal transplantation

Long-term graft outcome in patients with chronic allograft nephropathy after immunosuppression modifications

BACKGROUND/AIM

This retrospective study was conducted to assess the efficacy and safety of immunosuppression conversion on progression of chronic allograft nephropathy (CAN).

METHODS

One-hundred and seventy-four cyclosporin (CsA)-treated renal transplant recipients were studied. Patients were included if they had a biopsy-proven CAN (mild to moderate) with serum creatinine < or =3.5 mg/dL. Patient treatment was switched to either: (A) MMF/reduced dose CsA (MMF for azathioprine (Aza); n = 132); or (B) Aza/Tac for CsA (n = 42). Patient records were checked for graft function and survival, and for co-morbidities after conversion.

RESULTS

Mean follow-up before conversion was 52.2 +/- 31.1 and 47.9 +/- 27.4 months for groups A and B, respectively. There was significant deterioration of graft function in group B after five years (P < 0.5). Ten-year actuarial graft survival was 38% in group A and 19% in group B (P = 0.04). Nine patients (five patients and four patients in groups A and B, respectively) started dialysis within 12 months. Tacrolimus-treated patients had a lower insignificant incidence of hyperlipidemia (P = 0.05), but a significantly higher incidence of diabetes mellitus (P = 0.04).There was no significant change or difference in blood pressure between groups.

CONCLUSIONS

Our results suggest that in patients with CAN and deteriorating allograft function, CsA minimization and addition of MMF achieved favorable efficacies in retarding the decline of graft function. Further prospective studies with larger cohorts are needed for validation.

Upper gastrointestinal complications after renal transplantation: a 3-yr sequential study

BACKGROUND

Upper gastrointestinal complications have historically resulted in considerable morbidity and mortality to renal transplant recipients. Over the last decade, antiulcer prophylaxis with proton-pump inhibitors and immunosuppression with tacrolimus-based regimes have been introduced. Little has been written about foregut complications after renal transplantation since the use of these agents. The aim of this study was to compare the frequency of upper gastrointestinal complications after renal transplantation in patients treated with (i) omeprazole vs. ranitidine, and (ii) tacrolimus vs. cyclosporin based immunosuppression.

METHODS

Information on 236 patients undergoing renal transplantation between January 1996 and December 1998 was collected prospectively onto a computerized database.

RESULTS

Overall, 20 patients (8%) developed upper gastrointestinal complications, opportunistic infections accounted for 9/20 (45%). No patient developed gastroduodenal ulceration, required laparotomy, suffered graft loss or died. There was no significant difference in the frequency of complications between patients that received antisecretory therapy with omeprazole (9/118, 8%) and those that received ranitidine (11/118, 9%), nor between those that were on tacrolimus (7/101, 7%) and those on cyclosporin (13/135, 10%) based immunosuppression regimes. Patients that developed foregut complications were significantly older than those not developing complications (mean age 50 vs. 43 yrs, p=0.05). Further, patients that developed opportunistic infections were more frequently diabetic than those in whom opportunistic infections were not seen (4/31, 13% vs. 5/205, 2%), p=0.02.

CONCLUSIONS

We observed a low frequency (8%) of upper gastrointestinal tract complications after renal transplantation. There was no difference in the frequency of complications between patients on tacrolimus and those on cyclosporin based immunosuppression. Furthermore, the complication rates were similar in those that received omeprazole and those that received ranitidine as antiulcer prophylaxis, indicating the equivalence of these two agents in this setting.

The use of mycophenolate mofetil in transplant recipients

With the development of new immunosuppressive agents, the focus of anti-rejection therapy has shifted from prevention of acute allograft rejection to an emphasis on sufficient immunosuppression with minimal toxicity. Mycophenolate mofetil (MMF) is a recently developed immunosuppressive drug, which acts to inhibit T and B cell proliferation by blocking the production of guanosine nucleotides required for DNA synthesis. It also prevents the glycosylation of adhesion molecules that are involved in attachment of lymphocytes to endothelium and potentially in leukocyte infiltration of an allograft during an immune response. High-quality randomized clinical trials have demonstrated that MMF, when used with cyclosporine (CsA) and steroids, reduces the frequency and severity of acute rejection episodes in kidney and heart transplants, improves patient and graft survival in heart allograft recipients and increases renal allograft survival at 3 years. It has also been effective in reversing acute and resistant rejection episodes in heart, kidney and liver recipients. The ability of MMF to facilitate sparing of other immunosuppressive agents, particularly in CsA-related nephrotoxicity, is also promising. By permitting reduction in CsA doses, MMF may stabilize or improve renal graft function in patients with CsA-related nephrotoxicity or chronic allograft nephropathy. Early results of phase I and II trials evaluating MMF therapy in liver and combined pancreas/kidney transplant recipients are encouraging. The main adverse effects associated with oral or intravenous MMF are gastrointestinal and hematologic in nature. Although the direct costs of using MMF vs. azathioprine (AZA) are higher, the decreased incidence and treatment of acute rejection in patients treated with MMF supports its use as a cost-effective option during the first year following transplantation.Thus, MMF has become an important therapeutic tool in the transplant clinician's armamentarium. Ongoing issues to be resolved in clinical trials include the role of MMF in the absence of other potent agents, e.g., as monotherapy or with a steroid but without calcineurin inhibitor; whether MMF will have an impact on chronic allograft dysfunction; and the cost-effectiveness of treatment following the first year of transplantation.