Glucocorticoids interfere with mycophenolate mofetil bioavailability in kidney transplantation

BACKGROUND: Steroids have been shown to induce the hepatic glucuronyltransferase (GT) expression enhancing the activity of uridine diphosphate-GT, the enzyme responsible for mycophenolic acid (MPA) metabolism. The impact of steroids on MPA pharmacokinetics, however, has not been investigated to date. METHODS: As a part of a steroid-sparing clinical trial, we studied the effect of steroids on MPA bioavailability in 26 kidney transplant recipients. RESULTS: Despite that the MMF dose did not change significantly with time, dose-normalized MPA AUC0-12h was lower during the first month (triple therapy, high doses of steroids) than at month 6 post-surgery (triple therapy, low maintenance dose of steroids (32.94 +/- 10.98 vs. 50.87 +/- 22.37 microg/mL. h; P < 0.01). During the steroid tapering and withdrawal phase (from month 6 to 21 post-Tx), plasma MPA trough and peak concentration as well as AUC0-12h progressively increased, while plasma MPA clearance and MPAG (the major MPA metabolite) trough levels declined. Renal function was stable throughout. Since cyclosporine A (CsA) may interfere with MPA pharmacokinetics, MPA and CsA also were measured in an additional control group of 12 kidney transplant patients at month 21 post-Tx who were still on triple therapy (MMF, CsA and steroids). Despite a similar CsA exposure, the control group had a significantly lower MPA AUC0-12h and higher MPAG trough concentration than patients on dual therapy at month 21 post-Tx. CONCLUSION: These findings indicate that steroids interfere with MPA bioavailability, and that discontinuation of the drug results in higher MPA exposure, which may compensate at least in part for the lower immunosuppressive level achieved with the remaining dual therapy with CsA and MMF.     

Use of basiliximab with mycophenolate mofetil in kidney transplantation

INTRODUCTION: Randomized, placebo-controlled studies have determined that administration of basiliximab (chimeric IL-2 receptor antagonist) decreases the acute rejection rate in kidney transplantation when used in combination with cyclosporine, azathioprine, and steroids. We report our experience using basiliximab with mycophenolate mofetil, a calcineurin inhibitor, and steroids in kidney transplantation. METHODS: We retrospectively analyzed 127 patients who received their first kidney transplant between September 1, 1998, and December 30, 2000, including 59 who received basiliximab (22 living and 37 cadaveric donor recipients) and the 68 that did not receive this antibody (31 living and 37 cadaveric donor recipients). The groups were demographically comparable for risk factors such as race, peak of panel-reactive antibody, delayed graft function, donor age, and cold ischemia time. The analysis assessed serum creatinine levels, acute rejection, cytomegalovirus infection, and posttransplant lymphoproliferative disease incidence as well as patient and graft survival at 6 months. RESULTS: Serum creatinine levels were 3 +/- 3.1 and 2.6 +/- 2.5 mg/dL (P =.346) at discharge, 1.5 +/- 0.6 and 1.7 +/- 1.1 mg/dL (P =.098) at 1 month, and 1.5 +/- 0.7 and 1.6 +/- 0.7 mg/dL (P =.454) at 6 months posttransplantation for patients treated with versus without basiliximab, respectively. Only one episode of acute rejection was seen among patients treated with basiliximab within 1 month posttransplantation versus three episodes among patients treated without basiliximab (P =.382). Three patients (5.1%) treated with basiliximab and two patients (2.9%) treated without basiliximab developed acute rejection within 6 months posttransplantation (P =.536). Patient and graft survivals at 6 months posttransplantation were not significantly different between patients treated with versus without basiliximab (100% and 100% versus 100% and 98.3%, respectively). There was no increased incidence of cytomegalovirus infection with the use of basiliximab (5.1% vs 5.9%, P =.844). There was only one case of posttransplant lymphoproliferative disease within 6 months posttransplantation in a patient treated without basiliximab. CONCLUSION: These data suggest that the routine addition of basiliximab to a mycophenolate mofetil-based regimens does not appear to be warranted. A larger prospective randomized study with longer follow-up is needed to confirm these results.     

Tacrolimus and mycophenolate mofetil as first line immunosuppression after lung transplantation

The optimal maintenance therapy after lung transplantation remains to be established. The aim of this study was to analyse the impact of tacrolimus and mycophenolate mofetil (MMF) as first line immunosuppression on long-term survival and Bronchiolitis Obliterans Syndrome (BOS). From January 1996 through December 2006, all 155 recipients receiving tacrolimus and MMF as maintenance immunosuppression were included in this study. Tacrolimus and MMF was discontinued in 36 patients (23.2%). The overall survival rates were 91.6% at 6 months, 86.4% at 1 year, 74.9% at 3 years, 60.3% at 5 years and 32.4% at 10 years. The overall freedom from acute rejection was 74.6%, 63.2% and 59.4% at 1, 3, and 5 years respectively. The overall BOS-free survival was 95.6% at 1 year, 88.4% at 3 years, 69.5% at 5 years and 30.5% at 10 years. The development of BOS ≥ 1 was associated with a significantly increased risk of death and reduced long-term survival. The combination of tacrolimus and MMF offers safe and reliable maintenance immunosuppression after lung transplantation. However, substantial improvements of long-term survival and freedom from BOS might only be achieved by a change in organ allocation policies and patient management beyond differential immunosuppressive protocols.     

Analysis of a single-center experience with mycophenolate mofetil based immunosuppression in renal transplantation

Purpose. Acute rejection continues to be a major clinical issue in renal transplantation. Three large multicenter trials have demonstrated a 50% decline in biopsy‐proven rejection when mycophenolate mofetil (MMF) was given to renal transplant recipients with corticosteroids and cyclosporine. The purpose of this study was to compare the 6‐month outcome of renal transplant recipients using MMF and non‐MMF based immunosuppression protocols over a 4‐year period at a single center.
Methods. This retrospective study analyzed three patient groups defined by their immunosuppression protocol. The first group included patients who received a quadruple immunosuppression regimen of antilymphocyte induction (ATG), cyclosporine (CYA), azathioprine (AZA), and corticosteroids (CCS), and were transplanted between October 1993 and May 1995 (AZA group). The second group included patients who received a triple immunosuppression regimen of CYA, MMF, and CCS, and were transplanted between June 1995 and May 1996 (MMF group). The third group included patients who were transplanted between January 1997 and December 1997, and received an immunosuppression regimen of CYA and MMF with a reduced CCS dosing schema (reduced steroid group (RST)). Data were collected from a retrospective review of inpatient and outpatient clinical records.
Results. A total of 325 patients were included in the study (106 AZA, 106 MMF, 113 RST). The demographic characteristics of the three groups were similar; however, the mean donor age for the AZA group was 40±15.1 years versus 33±14.1 years and 34±13.1 years for the MMF and RST groups, respectively (p<0.043). The incidence of acute, biopsy‐proven rejection at 6 months was significantly less in the MMF group when compared with the AZA group [16 (15.1%) versus 35 (33%) patients, p=0.002]. However, the incidence of acute, biopsy‐proven rejection in the RST group (35 patients, 31%) was similar to that of the AZA group. Kaplan–Meier estimates for the cumulative incidence of acute rejection demonstrated a significant difference between the MMF group and the other two groups (p=0.0059). The AZA group had more severe rejection as demonstrated by the more frequent use of antilymphocyte therapy for rejection treatment (68.4% episodes) compared with the MMF (38.9%) and RST (47.6%) groups. After 6 months of follow‐up, 11 patients had lost their grafts (8, AZA; 1, MMF; 2, RST). One patient died in each of the AZA and RST groups due to hemorrhage and a pulmonary embolus, respectively. Four AZA patients were diagnosed with a malignancy (three post‐transplant lymphoproliferative disorder, one squamous skin cell carcinoma) compared with 2 MMF patients (prostate cancer, basal skin cell carcinoma) and no RST patients. Herpes zoster was the only infection that occurred more frequently in the MMF group (p=0.03). No other differences in infection rates were noted among the three groups. The initial length of hospital stay declined significantly over the 4‐year study period [11±4.3 d (AZA), 7.0±4.0 d (MMF), 6.2±3.3 d (RST), p<0.001]. Total number of hospital days for the first 6 months also followed a similar declining pattern. Despite using intravenous cyclosporine immediately post‐transplant in the MMF and RST groups, the incidence of delayed graft function was similar among the three groups. Average serum creatinine at 1 month was significantly lower in the MMF group (p=0.008), but no difference was noted at 3 and 6 months when compared with the AZA and RST groups.
Conclusion. This retrospective analysis indicates that MMF is an effective immunosuppressant. Decreased length of stay and less steroid resistant rejections with MMF is favorable for decreased hospital costs. However, the rebound in rejection rate with the RST group suggests that further study is needed to define the optimal use of this agent in combination with others to maximize effectiveness and minimize negative side effects.     

Excellent outcome of ABO-incompatible living kidney transplantation under pretransplantation immunosuppression with tacrolimus, mycophenolate mofetil, and steroid

INTRODUCTION: ABO-incompatible living kidney transplantation (LKT) has been performed to widen the indications for kidney transplantation. Since 2001, using a 7-day period of pretransplantation immunosuppression with tacrolimus (FK) plus mycophenolate mofetil (MMF) plus methylprednisolone (MP), we have observed a marked reduction in acute humoral/vascular rejection without any serious complications. PATIENTS AND METHODS: Forty-five adult patients underwent ABO-incompatible LKT at our institute between January 2000 and September 2002. There were 20 men and 25 women of mean age 33 years. Plasmapheresis was performed to remove anti-AB antibodies prior to kidney transplantation. In 2000, 13 patients were treated with FK plus MMF plus MP without 7-day pretransplantation immunosuppression (group 1). Since January 2001, we have administered FK (0.1 mg/kg/d) plus MMF (1-2 g/d) plus MP (125 mg/d) concomitantly with plasmapheresis starting from 7 days before transplantation in 32 patients (group 2). Splenectomy was performed at the time of kidney transplantation in all patients. RESULTS: Patient survival rate was 100% in both treatment groups. Graft survival rate was 92% and 97% in groups 1 and 2, respectively. One patient in group 1 lost the graft due to severe pancreatitis and 1 patient in group 2, due to severe humoral rejection. The incidence of acute rejection was 56% and 19% in group 1 and group 2, respectively. No patient experienced any lethal infectious complication. CONCLUSION: Pretransplantation immunosuppression for 7 days using FK, MMF, and MP in ABO-incompatible LKT provides an excellent outcome without severe infectious complications.     

The role of mycophenolate mofetil in kidney transplantation revisited

Since its regulatory approval in 1995, mycophenolate mofetil (MMF) has largely replaced azathioprine (AZA) as the anti-metabolite immunosuppressive of choice in kidney transplantation. While the initial industry-sponsored clinical trials suggested strong reductions in the incidence of acute rejection in the first six months post transplantation, long-term follow-up studies have failed to demonstrate a similar degree of benefit in overall graft and patient survival. In addition, several subsequent studies have raised questions on the potential attenuating effects of calcineurin inhibitor choice on MMF efficacy when compared to AZA. This review will revisit the question of whether the available evidence continues to support the superiority of MMF over AZA in kidney transplantation outcomes while comprehensively reviewing the available evidence from clinical trial data, systematic reviews, and registry studies.     

Corticosteroid-free immunosuppression with tacrolimus, mycophenolate mofetil, and daclizumab induction in renal transplantation

BACKGROUND: Corticosteroid-free maintenance immunosuppression after organ transplantation eliminates the well-known corticosteroid-related side effects and may help to improve long-term outcome. We investigated whether a corticosteroid-free tacrolimus (Tac)/mycophenolate mofetil (MMF) regimen, in combination with daclizumab (Dac) induction therapy, provides adequate immunosuppression after renal transplantation. METHODS: This 6-month, open-label, multicenter, parallel-group study involved 538 renal patients randomized (1:1) to a Dac/Tac/MMF regimen (n = 260) or a Tac/MMF/corticosteroids regimen (n = 278) as a control group. RESULTS: Of the patients who completed the study, 88.8% in the Dac/Tac/MMF group were free from corticosteroid therapy at month 6. The incidence of biopsy-proven acute rejection was 16.5% in both treatment groups; the incidence of biopsy-proven corticosteroid-resistant acute rejection was 4.3% and 5.0% with Tac/MMF/corticosteroids and Dac/Tac/MMF, respectively (P = NS for both comparisons). Renal function was also similar in both groups: median serum creatinine at month 6 was 125.0 micromol/L (Tac/MMF/corticosteroids) and 131.0 microml/L (Dac/Tac/MMF), P = 0.277. The overall safety profile was similar with both regimens. However, compared with the Tac/MMF/steroid regimen, a significantly reduced incidence of new-onset insulin-dependent diabetes mellitus (5.4% vs. 0.4%, P = 0.003) was found with steroid-free immunosuppression. Moreover, mean total cholesterol concentrations increased from baseline in the Tac/MMF/corticosteroids group by 0.19 mmol/L, whereas in the Dac/Tac/MMF group, levels decreased by 0.19 mmol/L, P = 0.005. CONCLUSIONS: Corticosteroid-free immunosuppression with a Dac/Tac/MMF regimen is as effective at preventing acute rejection after renal transplantation as a standard triple regimen of Tac/MMF/corticosteroids. Furthermore, the safety benefits reported with Dac/Tac/MMF treatment may help improve the long-term outcome for renal-transplant patients.     

Safe conversion of mycophenolate mofetil to azathioprine in kidney transplant recipients with sirolimus-based immunosuppression

Aim:   Mycophenolate mofetil (MMF) is a powerful immunosuppressive drug with established efficacy and safety. The long-term use of MMF may bring increased risk of for infection and malignancy and also increased cost of transplantation. The search for minimization of immunosuppressive protocol has led to an open randomized clinical trial of conversion from MMF to azathioprine (AZA).
Methods:   A total of 50 kidney allograft recipients treated with prednisone, sirolimus and MMF were randomized into two groups: converted (AZA group) and continuing (MMF group). The average duration of MMF therapy prior to conversion was 43 months in each group. Inclusion criteria included: patients with serum creatinine levels of less than 200 µmol/L; no past history of acute vascular rejection or recent acute rejection 6 months before randomization; and normal liver function tests.
Results:   Baseline demographics were similar in the two groups. During the 12 month observation period, there were no acute rejection episodes in either group. There were no significant differences in overall patient or graft survival or function. AZA-treated patients had a lower incidence of gastrointestinal complications ( P  = 0.03). Daily cost reduction in the AZA group was more than $US8.79/day per patient.
Conclusion:   In general, replacing MMF with AZA in stable renal transplant recipients is well tolerated and was cost effective with no increased risk of rejection. As the this study was on relatively small samples, larger and longer follow-up studies will be needed to confirm these expected advantages for the long-term outcome and to assess the long-term safety of this minimization of immunosuppressive therapy.     

Bilateral hand transplantation: bone healing under immunosuppression with tacrolimus, mycophenolate mofetil, and prednisolone

PURPOSE: Little is known about bone healing after composite tissue transplantation that requires pharmacologic immunosuppression. Bone integration and callus development were assessed in bilateral hand transplantation. METHODS: In this study the course of callus development and callus maturation were assessed by color Doppler sonography and radiography in a double hand transplant and compared with forearm replantation. RESULTS: After hand transplantation, ingrowth of small vessels at the bone junction was observed at week 3, calcified callus became visible at month 4, and bone union was completed at month 11. A similar time course of bone integration was observed after replantation. Plating offered sufficient stability. A recipient periostal flap is thought to have improved blood supply and favored development and induction of callus. CONCLUSIONS: Bone healing after hand transplantation under immunosuppression with tacrolimus, mycophenolate mofetil, and prednisolone is identical to that after forearm replantation.     

Maintenance therapy with mycophenolate mofetil after rituximab in pediatric patients with steroid-dependent nephrotic syndrome

Rituximab (RTX) has a significant steroid-sparing effect in children with steroid-dependent nephrotic syndrome (SDNS). However, patients are likely to relapse with the recovery of CD20+ cells. We conducted a small prospective cohort study with a historical control to evaluate the effect of RTX infusion followed by mycophenolate mofetil (MMF) as a maintenance therapy. Nine patients with SDNS who stopped their steroid treatment but were treated with MMF after RTX infusion were prospectively observed (group A). Seven patients with SDNS who discontinued steroid and immunosuppressive agents after RTX administration served as a control (group B). During the first year after the administration of RTX, six patients in group A and one patient in group B did not suffer a relapse (p < 0.05). The number of patients who relapsed during the 1 year preceding RTX treatment did not differ between the two groups [4.1 (A) vs. 5.7 (B)], but it was significantly lower in the MMF-treated group 1 year after the RTX treatment [0.4 (A) vs. 2.3 (B), p < 0.005]. The daily amount of prednisolone after the RTX treatment was lower in group A than in group B (0.11 vs. 0.46 mg/kg/day, respectively; p < 0.05). Three patients in group A and five patients in group B relapsed to SDNS and needed additional RTX treatment(s) within 1 year (odds ratio 5.0). Based on these results, we conclude that maintenance therapy with MMF after RTX is a good clinical option.     

Combined immunosuppression of mycophenolate mofetil and FK506 for myoblast transplantation in mdx mice

BACKGROUND: Overcoming adverse effects of immunosuppressors can be achieved by combining different drugs, thus allowing a dosage reduction. Myoblast transplantation is a potential therapy for Duchenne muscular dystrophy. Our research group previously established that FK506 (tacrolimus) is an effective immunosuppressive drug for myoblast transplantation in mice and monkeys. METHODS: In the present study, a reduced dose of FK506 at 1.0 mg/kg/day was used in combination with mycophenolate mofetil (MMF; 80 mg/kg/day) as an immunosuppressive protocol for myoblast transplantation. Graft success was evaluated by quantifying the number of dystrophin-positive fibers per muscle section that were injected with normal cells. RESULTS: MMF used alone could not prevent immune rejection of the transplanted myoblasts. MMF given in combination with FK506 immediately after transplantation reduced the success of myoblast transplantation by about 50%. A low dose of FK506 combined with MMF after the establishment of the graft (3 weeks) maintained graft success and controlled immune infiltration compared with a low dose of FK506 alone. However, lymphocyte infiltration was observed at longer term using a low dose of FK506 combined with MMF. CONCLUSIONS: The diminution of graft success when combining FK506 and MMF by the time of myoblast transplantation could be attributed to the inhibition of myoblast fusion by MMF. The use of MMF and FK506 after the establishment of the graft did not reduce graft success, however, this combination was not effective at controlling long-term immune rejection in comparison with the optimal dose of FK506 alone.     

Age-dependency of mycophenolate mofetil dosing in combination with tacrolimus after pediatric renal transplantation

BACKGROUND: Dosing of mycophenolate mofetil (MMF) must be lower in combination therapy with Tacrolimus (Tac) than with Cyclosporine. One study with mostly adolescent recipients recommended an MMF dose of 250 mg/m2 BID. Because this dose resulted in low area-under-the-curve (AUC) in our infant population, we retrospectively analyzed all available pharmacokinetic (PK) profiles in pediatric renal transplant patients on MMF plus Tac therapy to propose appropriate MMF dosing in pediatric patients of all ages. PATIENTS AND METHODS: Forty-four PK profiles were performed in 27 patients (median age, 11.6 years; range, 1.8-20.7 years). The investigations were performed at a median of 299 days (range, 24-3424) after transplantation. Ten patients were converted to Tac plus MMF, all others received this as primary therapy. For patients with repeated measurements, we calculated the average AUC and doses. We used first-order PK modeling to calculate the doses for a mycophenolic acid (MPA) AUC of 60 ug*h/mL and a Tac AUC of 150 ng*h/mL. RESULTS: The mean Tac dose was 2.6 +/- 1.2 mg/m2/d or 0.086 +/- 0.038 mg/kg/d, resulting in an average AUC of 120.6 +/- 30.4 ng*h/mL. The MMF dose was not normally distributed; the median dose was 549 mg/m2/d (range, 146-1413) and the median MPA AUC was 49.8 ug*h/mL (range, 26.7-156.0). The mean dose for a Tac AUC of 150 ng*h/mL was 3.50 +/- 1.77 mg/m2/d (0.117 +/- 0.058 mg/kg) and was independent of age or time after transplantation. By contrast, we found a negative relationship between the dose per m2 (r2 = 0.29; P = 0.0038) or per kg (r2 = 0.58; P < .0001) required for an MPA AUC of 60 ug*h/mL and patient age. Converted and primary patients behaved identically. The dosing requirement decreased from 500 mg/m2 BID in 2-year-old patients to 250 mg/m2 in adolescents. There was substantial interpatient variability of 44%. CONCLUSIONS: Higher MMF doses are required for young children. Our data suggest a starting dose for infants of 500 mg/m2 BID, with PK monitoring of MPA due to substantial interpatient variability.