Federico Oppenheimer

Enteric-coated mycophenolate sodium is therapeutically equivalent to mycophenolate mofetil in de novo renal transplant patients.

The introduction of mycophenolate mofetil (MMF) represented a major advance in transplant medicine, although optimal use may be limited by gastrointestinal (GI) side‐effects. An enteric‐coated formulation of mycophenolate sodium (EC‐MPS; myfortic®) has been developed with the aim of improving the upper GI tolerability of mycophenolic acid. Therapeutic equivalence of EC‐MPS (720 mg b.i.d.) and MMF (1000 mg MMF b.i.d.), with concomitant cyclosporine microemulsion (Neoral®) and corticosteroids, was assessed in 423 de novo kidney transplant patients recruited to a 12‐month, double‐blind study. Efficacy failure (biopsy‐proven acute rejection [BPAR], graft loss, death or loss to follow up) at 6 months (EC‐MPS 25.8% vs. MMF 26.2%; 95% CI: [−8.7, +8.0]) demonstrated therapeutic equivalence. At 12 months, the incidence of BPAR, graft loss or death was 26.3% and 28.1%, and of BPAR alone was 22.5% and 24.3% for EC‐MPS and MMF, respectively. Among those with BPAR, the incidence of severe acute rejection was 2.1% with EC‐MPS and 9.8% with MMF (p = ns). The safety profile and incidence of GI adverse events were similar for both groups. Within 12 months, 15.0% of EC‐MPS patients and 19.5% of MMF patients required dose changes for GI adverse events (p = ns). Enteric‐coated‐MPS 720 mg b.i.d. is therapeutically equivalent to MMF 1000 mg b.i.d. with a comparable safety profile.

Predictors of Success in Conversion from Calcineurin Inhibitor to Sirolimus in Chronic Allograft Dysfunction

Chronic allograft dysfunction (CAD) is a major cause of graft loss in long‐term kidney transplant recipients. To identify predictors of successful conversion from calcineurin inhibitor (CNI) to sirolimus (SRL) we investigated 59 renal transplant patients with CAD without histological signs of acute rejection. They received 12–15 mg SRL once, then 4–5 mg/day, target trough level 8–12 ng/mL. CNI dose was reduced by 50% simultaneously, and withdrawn at 1–2 months. Concomitant immunosuppression remained unchanged. After 1 year patient survival was 100% and graft survival 92%. In responders (54%) creatinine improved (2.75 ± 0.75 to 2.22 ± 0.64 mg/dL; p < 0.01). In nonresponders (46%) creatinine deteriorated (3.15 ± 1.02 to 4.44 ± 1.60 mg/dL; p < 0.01). Baseline renal function did not differ, however, baseline proteinuria (519 ± 516 vs. 1532 ± 867 mg/day, p < 0.01), histological grade of chronic allograft nephropathy (CAN) (1.2 ± 0.5 vs. 1.9 ± 0.6; p < 0.01), grade of vascular fibrous intimal thickening (1.2 ± 0.7 vs. 1.7 ± 0.7; p = 0.048) and number of acute rejections before conversion (0.73 ± 0.69 vs. 1.27 ± 0.96; p < 0.05) differed significantly between responders and nonresponders. In a multivariate analysis low proteinuria was the only independent variable. Proteinuria below 800 mg/day has a positive predictive value of 90%. Proteinuria at conversion below 800 mg/day is the only independent predictor for positive outcome in conversion from CNI to SRL in CAD.

Pharmacokinetics for once- versus twice-daily tacrolimus formulations in de novo kidney transplantation: a randomized, open-label trial.

Tacrolimus, a cornerstone immunosuppressant, is widely available as a twice‐daily formulation (Tacrolimus BID). A once‐daily prolonged‐release formulation (Tacrolimus QD) has been developed that may improve adherence and impart long‐lasting graft protection. This study compared the pharmacokinetics (PK) of tacrolimus in de novo kidney transplant patients treated with Tacrolimus QD or Tacrolimus BID. A 6‐week, open‐label, randomized comparative study was conducted in centers in Europe and Australia. Eligible patients received Tacrolimus QD or Tacrolimus BID. PK profiles were obtained following the first tacrolimus dose (day 1), and twice under steady‐state conditions. As secondary objectives, efficacy and safety parameters were also evaluated. Sixty‐six patients completed all PK profiles (34 Tacrolimus QD, 32 Tacrolimus BID). Mean AUC0–24 of tacrolimus on day 1 was approximately 30% lower for Tacrolimus QD than Tacrolimus BID (232 and 361 ng.h/mL, respectively), but was comparable by day 4. There was a good correlation and a similar relationship between AUC0–24 and Cmin for both formulations. Efficacy and safety data were also comparable over the 6‐week period. Tacrolimus QD can be administered once daily in the morning on the basis of the same systemic exposure and therapeutic drug monitoring concept as Tacrolimus BID.

Effect of cinacalcet on hypercalcemia and bone mineral density in renal transplanted patients with secondary hyperparathyroidism.

Background. Persistent secondary hyperparathyroidism (SHP) is the most frequent cause of hypercalcemia observed in approximately 10% of renal transplanted (RT) patients 1 year after surgery. Persistent SHP with hypercalcemia is an important factor of bone loss after renal transplantation. This study prospectively evaluates the effects of Cinacalcet therapy on serum calcium (SCa) and parathyroid hormone (PTH) blood levels, and basically on bone mineral density (BMD) in RT patients with persistent hyperparathyroidism. Methods. Nine RT patients (eight women, one man) with allograft function more than 6 months were included based on total SCa more than 10.5 mg/dL and intact parathyroid hormone (iPTH) concentration more than 65 pg/mL. After inclusion, patients started on a single daily oral dose of 30 mg of Cinacalcet. At inclusion and every study visit blood levels of creatinine, Ca, P, alkaline phosphatase, iPTH 1,25- dihydroxyvitamin D3, and 25-hydroxyvitamin D3 were assessed. Baseline and at the end of study radial BMD were measured. Study follow-up was 12 months. Results. During the study period, SCa decreased from 11.72±0.39 to 10.03±0.54 mg/dL (P<0.001). iPTH decreased from 308.85±120.12 to 214.66±53.75 mg/dL (P<0.05). The mean serum creatinine decreased from 1.58±0.34 to 1.25±0.27 mg/dL (P=0.03) and the mean radial BMD increased from 0.881±0.155 to 0.965±0.123 gr/cm2 (P<0.05). There were no significant changes in the other parameters assessed. One patient was excluded for gastrointestinal intolerance. Conclusions. In RT patients with hypercalcemia secondary to persistent SHP, Cinacalcet corrects hypercalcemia and PTH, simultaneously improving BMD.

Efficacy of eculizumab in the treatment of recurrent atypical hemolytic-uremic syndrome after renal transplantation.

REFERENCES 1. Tilney N, Murray J, Thistlethwaite R, et al. Promotion of altruistic donation. Transplantation 2009; 88: 847. 2. Nejatisafa AA, Mortaz-Hedjri S, Malakoutian T, et al. Quality of life and life events of living unrelated kidney donors in Iran: A multicenter study. Transplantation 2008; 86: 937. 3. Hippen B. Organ sales and moral travails: Lessons from the Living Kidney Vendor Program in Iran. Policy Analysis no 614. Washington, DC, Cato Institute 2008. 4. Ghods AJ. Renal transplantation in Iran. Nephrol Dial Transplant 2002; 17: 222. 5. Ghods AJ, Ossareh S, Khosravani P. Comparison of some socioeconomic characteristics of donors and recipients in a controlled living unrelated donor renal transplantation program. Transplant Proc 2001; 33: 2626. 6. Zargooshi J. Quality of life of Iranian kidney “donors.” J Urol 2001; 166: 1790. 7. Schold JD, Srinivas TR, Kayler LK, et al. The overlapping risk profile between dialysis patients listed and not listed for renal transplantation. Am J Transplant 2008; 8: 58.

The pharmacokinetics of mycophenolate mofetil in renal transplant recipients receiving standard-dose or low-dose cyclosporine, low-dose tacrolimus or low-dose sirolimus: the Symphony pharmacokinetic substudy

BACKGROUND Exposure to mycophenolic acid (MPA), the primary active metabolite of mycophenolate mofetil (MMF), is correlated with therapeutic efficacy of MMF but varies depending on the concomitantly administered immunosuppressive drugs. METHODS A 3-month pharmacokinetic substudy of the prospective, randomized, multicentre, open-label Symphony study was performed. Eighty-three adult renal transplant patients received standard-dose cyclosporine, MMF 2 g/day and corticosteroids, or daclizumab induction, MMF 2 g/day and corticosteroids plus low-dose cyclosporine, low-dose tacrolimus or low-dose sirolimus. The area under the concentration-time curve (AUC(0-12)) of MPA and its metabolites between treatment groups was compared. Pharmacokinetic sampling was performed before MMF administration and at 20, 40, 75 min; 2, 3, 6, 8, 10 and 12 h post-dose on Day 7 and Months 1 and 3. RESULTS Compared with standard-dose cyclosporine, patients receiving low-dose tacrolimus or low-dose sirolimus had significantly higher AUC(0-12) values for MPA at Day 7 and Month 1 and for free MPA at Day 7, and significantly lower AUC(0-12) values for 7-O-MPA-glucuronide (MPAG) at Month 1 and for acyl-glucuronide at Months 1 and 3 (P < 0.05). AUC(0-12) of MPA and free MPA was significantly greater with low-dose tacrolimus and low-dose sirolimus than with low-dose cyclosporine in the first month (P < 0.05). The ratio of MPA to MPAG exposure was significantly higher in the three low-dose groups than in the standard-dose cyclosporine group (P < 0.05). CONCLUSIONS Standard- and low-dose cyclosporine reduces the exposure of MPA and free MPA compared to low-dose tacrolimus or low-dose sirolimus in patients given the same dose of MMF.

Estimated one-year glomerular filtration rate is the best predictor of long-term graft function following renal transplant

Background. Long-term success of renal transplantation depends upon the quality of the donor organ, avoidance of peritransplant and early posttransplant damage (rejection), and optimal maintenance of graft function after the first 6–12 months. Glomerular filtration rate (GFR) at 1 year is a standard way to evaluate short-term success, whereas calculated GFR at 5 years gives a better appreciation of long-term outcomes. The objective of this study was to assess the effect of various demographic and transplant-related parameters on renal function via GFR at 1 year and 5 years post transplantation, using univariate and multivariate data analysis. Methods. Data on 1-year GFR were available from 10,397 patients, whereas 2,889 patients provided data on both 1-year and 5-year GFR. All patients were enrolled in the Neoral Multinational Observational Study in Transplantation (Neoral-MOST), an ongoing, prospective, observational study of adult renal transplant recipients. Results. One-year GFR was the most relevant predictor for 5-year GFR. In a multifactorial analysis (ANCOVA) using 1-year GFR as a continuous variable, the effects of several highly relevant parameters from univariate analysis (such as acute rejection and delayed graft function) on 5-year GFR appeared to be fully mediated by their influence on 1-year GFR, whereas immunological risk factors like HLA match or previous transplantation had an ongoing effect on graft function beyond year 1. Conclusions. The findings of this study corroborate and augment data from previous registry surveys, and confirm the importance of observational studies in investigating the role of peritransplant parameters on long-term graft outcome.

mTOR inhibitor–associated proteinuria in kidney transplant recipients

The use of mammalian target of rapamycin inhibitor (mTOR-I) after kidney transplantation has been associated with a higher incidence of proteinuria compared with calcineurin inhibitors (CNIs). This review will focus on mTOR-I-associated proteinuria in different settings after kidney transplantation: de novo mTOR-I treatment in combination with CNI, de novo mTOR-I-containing and CNI-free treatment, early conversion from a CNI-based regimen to an mTOR-I-based regimen, and late conversion. Some possible mechanisms of mTOR-I-induced proteinuria will also be reviewed.

FTY720/Cyclosporine Regimens in De Novo Renal Transplantation: A 1-Year Dose-Finding Study

FTY720 is a novel immunomodulator being investigated for rejection prophylaxis in renal transplantation when combined with full‐dose cyclosporine (CsA; FDC). This 1‐year phase II study compared FTY720 plus FDC (Neoral®) with FTY720 plus reduced‐dose CsA (RDC) and mycophenolate mofetil (MMF) plus FDC in de novo renal transplant patients. Patients were randomized 2:2:2:1 to FTY720 5 mg plus RDC (n = 72); FTY720 2.5 mg plus RDC (n = 74); FTY720 2.5 mg plus FDC (n = 76); or MMF plus FDC (n = 39) for 12 months. CsA exposure in the RDC group was reduced on average by 50% as assessed by C2 monitoring. The primary efficacy endpoint was the composite incidence of biopsy‐proven acute rejection (BPAR), graft loss, death or premature study discontinuation. The incidences for this composite endpoint were 24% and 22%, respectively, for FTY720 5 mg plus RDC and FTY720 2.5 mg plus FDC versus 39% for MMF plus FDC. Patients receiving FTY720 2.5 mg plus RDC were discontinued from treatment due to risk of under‐immunosuppression. FTY720 2.5 mg plus FDC and FTY720 5 mg plus RDC were safe and effective in de novo renal transplant patients over 12 months.

Risk factors for graft loss and mortality after renal transplantation according to recipient age: a prospective multicentre study

Background To describe the causes of graft loss, patient death and survival figures in kidney transplant patients in Spain based on the recipients age. Methods The results at 5 years of post-transplant cardiovascular disease (CVD) patients, taken from a database on CVD, were prospectively analysed, i.e. a total of 2600 transplanted patients during 2000–2002 in 14 Spanish renal transplant units, most of them receiving their organ from cadaver donors. Patients were grouped according to the recipients age: Group A: <40 years, Group B: 40–60 years and Group C: >60 years. The most frequent immunosuppressive regimen included tacrolimus, mycophenolate mofetil and steroids. Results Patients were distributed as follows: 25.85% in Group A (>40 years), 50.9% in Group B (40–60 years) and 23.19% in Group C (>60). The 5-year survival for the different age groups was 97.4, 90.8 and 77.7%, respectively. Death-censored graft survival was 88, 84.2 and 79.1%, respectively, and non death-censored graft survival was 82.1, 80.3 and 64.7%, respectively. Across all age groups, CVD and infections were the most frequent cause of death. The main causes of graft loss were chronic allograft dysfunction in patients <40 years old and death with functioning graft in the two remaining groups. In the multivariate analysis for graft survival, only elevated creatinine levels and proteinuria >1 g at 6 months post-transplantation were statistically significant in the three age groups. The patient survival multivariate analysis did not achieve a statistically significant common factor in the three age groups. Conclusions Five-year results show an excellent recipient survival and graft survival, especially in the youngest age group. Death with functioning graft is the leading cause of graft loss in patients >40 years. Early improvement of renal function and proteinuria together with strict control of cardiovascular risk factors are mandatory.