Mycophenolate mofetil monotherapy: an optimal, safe, and efficacious immunosuppressive maintenance regimen in kidney transplant patients

Mycophenolate Monotherapy in HLA-Matched Kidney Transplant Recipients: A Case Series of 20 Patients

The ideal minimizing strategy for maintenance immunosuppression in HLA-matched kidney transplant recipients (KTR) is unknown. We hypothesized that mycophenolate (MPA) monotherapy is a safe and effective approach for maintenance therapy in this group of KTR.

Methods

Data were abstracted for 6-antigen HLA-matched KTR between 1994 and 2013. Twenty recipients receiving MPA monotherapy secondary to infection, cancer, calcineurin inhibitor (CNI) side effects, or immunosuppression minimization strategies were evaluated in this case series.

Results

MPA monotherapy had a low incidence of death-censored graft failure (3.19/100 person-y), rejection (0/100 person-y), hospitalization (1.62/100 person-y), malignancy (3.61/100 person-y), and infection (1.75/100 person-y). Further, 12-month mean or median serum creatinine (1.29 mg/dL), estimated glomerular filtration rate (64.3 mL/min/1.73 m2), urine protein creatinine ratio (143.2 mg/g), hemoglobin (13.9 g/dL), platelets (237.8 K/uL), and white blood cell count (9.04 K/uL) were favorable. There was a successful conversion rate of 90% (18 of 20) with 2 patients converting back to CNI-based regimens secondary to recurrence of membranous nephropathy and post-transplant lymphoproliferative disorder.

Conclusions

Our findings indicate that MPA monotherapy may be a promising immunosuppression minimization strategy for HLA-matched KTR.

Steroid avoidance or withdrawal for kidney transplant recipients

BACKGROUND

Steroid-sparing strategies have been attempted during the last two decades in order to avoid morbidity in kidney transplant recipients. Previous systematic reviews of steroid withdrawal after kidney transplantation have shown significant increases in acute rejection and an increase in graft failure rates. Steroid avoidance in kidney transplantation is increasingly attempted and the possible benefits or harms have never been a subject of a systematic review.

OBJECTIVES

To assess the safety and efficacy of steroid withdrawal or avoidance in patients receiving a kidney transplant.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE and EMBASE, references lists and abstracts from international transplantation society scientific meetings.

SELECTION CRITERIA

Randomised controlled studies (RCTs) of steroid avoidance or withdrawal were included providing that one treatment arm consisted in steroid avoidance or withdrawal and intention-to-treat rates of acute rejection and graft failure were clearly established after steroid avoidance or use or withdrawal or continuation. Observational studies were tabulated.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and results expressed as risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 30 RCTs (5949 participants). Steroid-sparing strategies showed no effect on mortality or graft loss including death. Patients on any steroid-sparing strategy showed a higher risk of graft loss excluding death than those with conventional steroid use (RR 1.23, 95% CI 1.00 to 1.52), especially in those not receiving MMF/Myf or everolimus (RR 1.70, 95% CI 1.00 to 2.90). Acute rejection was more frequent with a steroid-sparing strategy (RR 1.27, 95% CI 1.14 to 1.40) and more frequent after steroid withdrawal or avoidance when compared with standard steroid treatment when cyclosporin (CsA) was used. Steroid-sparing and withdrawal strategies showed benefits in reducing antihypertensive drug need, serum cholesterol, antihyperlipidaemic drug need, new-onset diabetes after transplantation (NODAT) requiring any treatment and cataracts. Steroid avoidance did not alter serum cholesterol, but was associated with less frequent NODAT requiring any treatment. Cardiovascular events were reduced with steroid avoidance. Reduced antihypertensive drug need and serum cholesterol were similar with CsA or tacrolimus (TAC). Reduced antihyperlipidaemic drug need was only evident with TAC, whereas the reduction in NODAT requiring any treatment was only evident with CsA. Infection was lower in steroid-sparing patients using CsA (RR 0.88, 95% CI 0.78 to 1.00). NODAT requiring any treatment was less frequent with steroid avoidance than with steroid withdrawal.

AUTHORS' CONCLUSIONS

This review confirms that steroid avoidance and steroid withdrawal strategies in kidney transplantation are not associated with increased mortality or graft loss despite an increase in acute rejection. These immunosuppression strategies may allow safe steroid avoidance or elimination a few days after kidney transplantation if antibody induction treatment is prescribed or after three to six months if such induction is not used.

Toxicity-sparing protocols using mycophenolate mofetil in renal transplantation

The introduction of triple-therapy regimens that include a calcineurin inhibitor (CNI), steroids, and azathioprine greatly reduced the risk of acute rejection in renal transplantation. However, the long-term use of both CNIs and steroids is associated with serious toxicities that ultimately can impact patient/graft survival. Mycophenolate mofetil (MMF), a highly effective immunosuppressant with no known nephrotoxicity, has been shown to provide benefits in preserving long-term renal allograft function relative to azathioprine. For these reasons, MMF has become an integral component of toxicity-sparing maintenance regimens that seek to minimize patient exposure to CNIs and steroids. This paper provides an overview of current strategies for reducing the toxicities associated with these agents, which include both withdrawal and avoidance regimens with or without induction therapy. Data are accumulating that toxicity-sparing regimens involving MMF are safe and decrease the risk of side effects that accompany the use of CNIs and steroids. Future studies will determine how to best implement these regimens in the renal transplant population.

Tacrolimus and mycophenolate mofetil provide effective immunosuppression in rat laryngeal transplantation

OBJECTIVES/HYPOTHESIS

Tacrolimus is efficacious in several transplantation settings. Some studies have demonstrated improved results using combination therapy with mycophenolate mofetil. Our primary objective was to evaluate the efficacy and optimal dosing of tacrolimus in preventing rejection, using an established rat model of laryngeal transplantation. Further, the ability of mycophenolate to allow lower dosing of tacrolimus while achieving equivalent immunosuppression was investigated.

STUDY DESIGN

A dosage efficacy study with 10 experimental arms was conducted.

METHODS

Dosage groups were 0.1, 0.2, 0.3, and 0.6 mg/kg tacrolimus alone and 0.1 mg/kg tacrolimus combined with 15 mg/kg mycophenolate mofetil, 0.1 mg/kg tacrolimus combined with 30 mg/kg mycophenolate mofetil, 0.1 mg/kg tacrolimus combined with 40 mg/kg mycophenolate mofetil, 0.2 mg/kg tacrolimus combined with 15 mg/kg mycophenolate mofetil, 0.2 mg/kg tacrolimus combined with 30 mg/kg mycophenolate mofetil (30 d only), and 0.2 mg/kg tacrolimus combined with 40 mg/kg mycophenolate mofetil. Each group contained 8 to 10 rats. Grafts were harvested for histopathological analysis on day 15 or 30 after transplantation. Histopathological appearance of the graft was blindly graded according to an established scale. Dosage groups were compared on rejection score using Wilcoxon's rank sum test and the Jonckheere-Terpstra test for trend.

RESULTS

There was a significant association between increasing dose of tacrolimus and decreasing rejection score at both 15 and 30 days (P <.001). In the groups treated with 0.1 mg/kg T, an increasing dose of mycophenolate was associated with lower rejection scores at both 15 and 30 days (P =.001). In the group treated with 0.2 mg/kg T, there was no evidence that the addition of mycophenolate resulted in lower rejection at 15 days. However, at 30 days, combination therapy with increasing doses of mycophenolate was associated with decreasing rejection score (P =.002).

CONCLUSIONS

Tacrolimus is an effective immunosuppressive agent for laryngeal transplantation. Mycophenolate mofetil allows lower doses of tacrolimus to be used while preserving graft viability in the early post-transplantation period.