Mycophenolate mofetil prevents the progression of chronic kidney allograft nephropathy

Mycophenolate Mofetil in Pediatric Renal Transplantation

INTRODUCTION

Since kidney transplantation is the therapy of choice for children with end-stage renal disease (ESRD), we investigated the effects of mycophenolate mofetil (MMF) in pediatric renal transplantation.

METHODS AND SUBJECTS

Two hundred sixteen children received renal transplants between 1985 and 2003: 100 patients received MMF with cyclosporine and prednisolone (cases), and 116 patients, azathioprine with cyclosporine and prednisolone (controls).

RESULTS

The MMF group (100 patients) showed better graft survival and function than the AZA group (116 patients). Patients who received MMF immediately after transplantation experienced less graft loss and acute rejection episodes in the first 3 months after transplantation (P < .05). Patients who received MMF at the time of diagnosis of chronic rejection had stable renal function and remarkably better graft survival than those with chronic rejection who received AZA instead of MMF (P < .05).

CONCLUSION

This study suggests that MMF may stop persistent graft dysfunction in chronic rejection, improving graft survival in the short and long terms posttransplantation.

Improvement in long-term graft survival in cadaveric renal transplant recipients treated with mycophenolate mofetil

Though mycophenolate mofetil has markedly reduced the incidence of acute rejection in renal transplantation, a significant improvement in graft survival has been more difficult to demonstrate. This retrospective study compares an historical control group of 210 consecutive renal transplant patients, who had received ATG induction associated with cyclosporin, prednisolone and azathioprine, with 187 patients receiving mycophenolate instead of azathioprine. The incidence of acute rejection was decreased with mycophenolate. In rejection-free patients, the 3-year graft survival rates were equivalent. In contrast, graft survival at 3 years improved significantly for patients who experienced a rejection crisis and remained under the initial triple drug regimen with mycophenolate compared to the patients of the historical group who were kept on azathioprine after a rejection episode. In conclusion, mycophenolate mofetil is not only able to reduce the incidence of acute rejection but could also improve the prognostic significance of acute rejection crises.

Cyclosporine withdrawal and mycophenolate mofetil treatment effects on the progression of chronic cyclosporine nephrotoxicity

BACKGROUND

Recent clinical trials of mycophenolate mofetil (MMF) in chronic allograft nephropathy (CAN) demonstrated that the dose of cyclosporine A (CsA) is one of the critical factors in determining graft function in CAN, but the effect of MMF on chronic CsA nephropathy is undetermined. We undertook this study to evaluate the effect of MMF on CsA-induced nephrotoxicity in an animal model of chronic CsA nephropathy.

METHODS

In the first experiment, Sprague-Dawley rats on a low-salt diet were treated with CsA (7.5 mg/kg per day) for 10 weeks, or were treated with CsA for five weeks and then MMF (20 mg/kg per day) was administered five weeks later. In the second experiment, rats were treated with CsA for five weeks, and CsA was then withdrawn for five weeks with or without MMF treatment. Renal function, histologic parameters (tubulointerstitial fibrosis, arteriolopathy, ED-1-positive cells, renin-positive glomeruli, TUNEL-positive cells) and the expression of osteopontin and transforming growth factor (TGF)-beta1 mRNA expressions were compared for different treatment groups.

RESULTS

CsA-treated rats showed decreased renal function and increased histologic parameters compared with the vehicle (VH)-treated rats. The addition of MMF did not improve these parameters compared with the CsA-treated rats. With CsA withdrawal, renal function and histologic parameters were significantly improved compared with the CsA-treated rats, and MMF treatment after CsA withdrawal further improved the histologic parameters. At the molecular level, the addition of MMF did not decrease the expression of osteopontin and transforming growth factor-beta1 (TGF-beta1) mRNAs, which were increased in the CsA-treated rat kidney. With CsA withdrawal, the expression of both mRNAs was significantly decreased compared with the CsA group, and a further decrease was observed with MMF treatment after CsA was withdrawn.

CONCLUSION

The combined treatment of CsA and MMF does not prevent the development of chronic CsA nephrotoxicity, but MMF treatment after CsA withdrawal does improve chronic CsA nephrotoxicity. This finding provides a rationale for MMF treatment in chronic CsA nephrotoxicity.