Stefano Federico

Mycophenolate mofetil versus azathioprine for prevention of acute rejection in renal transplantation (MYSS): a randomised trial

BACKGROUND Mycophenolate mofetil has replaced azathioprine in immunosuppression regimens worldwide to prevent graft rejection. However, evidence that its antirejection activity is better than that of azathioprine has been provided only by registration trials with an old formulation of ciclosporin and steroid. We aimed to compare the antirejection activity of these two drugs with a new formulation of ciclosporin. METHODS The mycophenolate steroids sparing multicentre, prospective, randomised, parallel-group trial compared acute rejections and adverse events in recipients of cadaver-kidney transplants over 6-month treatment with mycophenolate mofetil or azathioprine along with ciclosporin microemulsion (Neoral) and steroids (phase A), and over 15 more months without steroids (phase B). The primary endpoint was occurrence of acute rejection episodes. Analysis was by intention to treat. FINDINGS 168 patients per group entered phase A. 56 (34%) assigned mycophenolate mofetil and 58 (35%) assigned azathioprine had clinical rejections (risk reduction [RR] on mycophenolate mofetil compared with azathioprine 13.7% [95% CI -25.7% to 40.7%], p=0.44). 88 patients in the mycophenolate mofetil group and 89 in the azathioprine group entered phase B. 14 (16%) taking mycophenolate mofetil and 11 (12%) taking azathioprine had clinical rejections (RR -16.2%, [-157.5% to 47.5%], p=0.71). Average per-patient costs of mycophenolate mofetil treatment greatly exceeded those of azathioprine (phase A 2665 Euros [SD 586] vs Euros 184 [62]; phase B 5095 Euros [2658] vs 322 Euros [170], p<0.0001 for both). INTERPRETATION In recipients of cadaver kidney-transplants given ciclosporin microemulsion, mycophenolate mofetil offers no advantages over azathioprine in preventing acute rejections and is about 15 times more expensive. Standard immunosuppression regimens for transplantation should perhaps include azathioprine rather than mycophenolate mofetil, at least for kidney grafts.

Mycophenolate Mofetil versus Azathioprine for Prevention of Chronic Allograft Dysfunction in Renal Transplantation: The MYSS Follow-Up Randomized, Controlled Clinical Trial

The Mycophenolate Steroids Sparing (MYSS) study found that in renal transplant recipients who were on immunosuppressive therapy with the cyclosporine microemulsion Neoral, mycophenolate mofetil (MMF) was not better than azathioprine in preventing acute rejection at 21 mo after transplantation and was 15 times more expensive. The MYSS Follow-up Study, an extension of MYSS, was aimed at comparing long-term outcome of 248 MYSS patients according to their original randomization to MMF (1 g twice daily) or azathioprine (75 to 100 mg/d). Primary outcome was estimated GFR at 5 yr after transplantation. Mean 5-yr GFR difference between azathioprine and mycophenolate was 4.67 ml/min per 1.73 m(2) (95% confidence interval [CI] -0.43 to 9.77 ml/min per 1.73 m(2); P = 0.07). GFR from month 6 (mean +/- SEM: 54.3 +/- 1.6 versus 53.9 +/- 1.5 ml/min per 1.73 m(2); P = 0.83) to month 72 after transplantation (49.5 +/- 2.2 versus 47.3 +/- 2.4 ml/min per 1.73 m(2); P = 0.50); GFR slopes (mean +/- SEM: -1.10 +/- 0.56 versus -1.23 +/- 0.31 ml/min per 1.73 m(2) per year; P = 0.83); and 72-mo patient mortality (4.0 versus 4.0% [P = 0.95]; HR 0.96; 95% CI 0.28 to 3.31; P = 0.95), graft loss (6.8 versus 6.1% [P = 0.82]; HR 0.89; 95% CI 0.32 to 2.46; P = 0.83), incidence of persistent proteinuria (25.0 versus 27.4%; P = 0.72), late (>6 mo after transplantation) rejections (25.3 versus 21.2%; P = 0.53), and adverse events were similar on azathioprine (n = 124) and MMF (n = 124), respectively. Outcomes in the two groups were comparable also among patients with or without steroid therapy, considered separately. In kidney transplantation, the long-term risk/benefit profile of MMF and azathioprine therapy in combination with cyclosporine Neoral is similar. In view of the cost, standard immunosuppression regimens for kidney transplantation should perhaps include azathioprine rather than MMF.

Everolimus with very low-exposure cyclosporine a in de novo kidney transplantation: a multicenter, randomized, controlled trial.

Background. In combination with everolimus (EVL), cyclosporine A (CsA) may be used at low exposure, so reducing the risk of renal dysfunction in renal transplant recipients (RTR). We evaluated whether higher exposure of EVL could allow a further reduction of CsA. Methods. De novo RTR were randomized to standard exposure EVL (C0 3–8 ng/mL) with low-concentration CsA (C2 maintenance levels 350–500 ng/mL, group A) or higher EVL exposure (C0 8–12 ng/mL) with very low-concentration CsA (C2 maintenance levels 150–300 ng/mL, group B). The primary endpoints were 6-month creatinine clearance (CrCl) and biopsy-proven acute rejection (BPAR) rate. After 6 months, patients were followed up (observational extension) to 12 months. Results. Two hundred eighty-five RTR (97% from deceased donors) were enrolled. Two patients per group died (1.4%). The 6-month death-censored graft survival was 90.2% in group A and 97.9% in group B and was unchanged at 12 months (P=0.007). There was no significant difference between groups at 6 months in CrCl (59.9 vs. 57.8 mL/min) and BPAR rates (14.7% vs. 11.9%) and also at 12 months (CrCl 62.5±20.7 vs. 61.3±22.0 mL/min, BPAR 14.7% vs. 14.1%). No significant differences were seen in treated acute rejections, steroid-resistant acute rejections, treatment failures, or delayed graft function, although there was a trend to better results in group B. Conclusions. EVL given at higher exposure for 6 months plus very low CsA concentration may obtain low acute rejection rate and good graft survival in De novo renal transplantation. However, there was no difference between groups in CrCl.

Changes in middle cerebral artery blood velocity in uremic patients after hemodialysis.

Background and Purpose Strokes are a frequent complication in uremic patients on dialysis. We wanted to evaluate the effect of this treatment on cerebral hemodynamic parameters, particularly those of patients with carotid stenosis, who are at higher risk for atherothrombotic ischemic events. Methods We used transcranial Doppler ultrasonography to evaluate blood velocity of the middle cerebral artery in 18 uremic patients before and after hemodialysis. Carotid stenosis was evaluated by echo-Doppler investigation. Six patients were also studied before and after recombinant human erythropoietin treatment. Results Dialysis treatment decreased mean blood velocity in all patients (p<0.001). Eight of 18 patients (44%) with mild (16–50%), moderate (51–80%), or severe (>80%) carotid stenosis had lower velocity than patients with normal carotid arteries (p<0.01), and they experienced a further decrease to even lower levels after hemodialysis (p<0.05). In patients treated with recombinant human erythropoietin, hematocrit increased from 28±8% to 37±5% (p<0.001), and blood velocity had a further decrease by 11%. All changes were associated with modifications toward normality of pH, Paco2, and hematocrit. Conclusions Transcranial Doppler ultrasonography represents a useful method for monitoring cerebral circulation of uremic patients, especially of those at possible risk for ischemia.

Zaleplon improves sleep quality in maintenance hemodialysis patients.

Background/Aim: A recent survey has shown that insomnia is still a very common problem in maintenance hemodialysis (MHD) patients. The aim of the present study was to test the effects of zaleplon (ZAL), a new nonbenzodiazepine hypnotic drug, on the sleep quality of MHD patients with insomnia. Methods: The sleep quality was assessed by the Pittsburgh questionnaire in 10 patients (6 males/4 females) with insomnia on MHD; these patients underwent a randomized double-blind crossover study versus placebo (PLA). The main exclusion criterion was the presence of any possible cause of insomnia related to other concurrent diseases. Results: Treatment with ZAL significantly improved the total score of sleep quality (p < 0.03 vs. PLA). The analysis of the single components revealed that treatment with ZAL was associated with a higher subjective sleep quality (p < 0.01 vs. PLA) and a reduced sleep latency (p < 0.01 vs. PLA). The duration of sleep was not modified by ZAL, whereas a significant improvement was detected in habitual sleep efficacy (p < 0.05 vs. PLA). No peculiar side effect was recorded on ZAL. Blood parameters did not change, nor were differences recorded in the dialysis parameters (body weight gain, blood pressure) throughout the study. Conclusions: This study suggests that ZAL has a positive effect on the sleep quality in MHD patients. The absence of side effects and its pharmacodynamic properties make ZAL a useful drug in uremic patients.

Pharmacokinetic Interaction between Levofloxacin and Ciclosporin or Tacrolimus in Kidney Transplant Recipients: Ciclosporin, Tacrolimus and Levofloxacin in Renal Transplantation

Background and objectiveBacterial infections are common complications after organ transplantation. Fluoroquinolones are frequently used for treatment because of their broad spectrum of activity; but some of them, such as Ciprofloxacin and norfloxacin, are reported to increase blood concentration of Ciclosporin because they are metabolised by the liver through the same enzymatic pathway, the cytochrome P450 system. This study was performed to establish whether levofloxacin, a more recent fluoroquinolone that undergoes limited hepatic metabolism, interferes with metabolism and excretion of either Ciclosporin microemulsion or tacrolimus.MethodsPharmacokinetic studies were carried out in two groups of renal transplant patients, on either Ciclosporin or tacrolimus treatment, before and at the sixth day of treatment with levofloxacin.ResultsLevofloxacin significantly increased the mean area under the blood concentration-time curve (AUC) and the other pharmacokinetic parameters of Ciclosporin and tacrolimus by about 25%. The interference of levofloxacin on the hepatic metabolism of these drugs was demonstrated by the concomitant decrease by 5% of polyclonal Ciclosporin concentration, which is the expression of parent drug and its metabolites. Both before and during levofloxacin treatment we observed trough concentrations of monoclonal and polyclonal Ciclosporin significantly lower in the evening (C12) than in the morning (C0); this observation suggests a circadian variation in the metabolism of this drug. However, no difference between C0 and C12 was observed with tacrolimus, confirming its more predictable bioavailability.ConclusionOur data demonstrate that levofloxacin partially inhibits the metabolism of both Ciclosporin microemulsion and tacrolimus, and therefore close therapeutic monitoring of these two drugs should be recommended during levofloxacin therapy.

Evalutation of mycophenolic acid systemic exposure by limited sampling strategy in kidney transplant recipients receiving enteric-coated mycophenolate sodium (EC-MPS) and cyclosporine

BACKGROUND Enteric-coated mycophenolate sodium (EC-MPS) and mycophenolate mofetil (MMF) are prodrugs of mycophenolic acid (MPA). Although many patients still receive MMF as an inosine monophosphate dehydrogenase inhibitor, EC-MPS could be considered a reliable alternative to MMF in the immunosuppressive protocols of kidney transplant recipients. MPA shows high pharmacokinetic variability and consequently a 12-h area under the curve (AUC(0-12)) should be used to guide the therapeutic dosage. However, patient compliance and economic costs make MPA AUC(0-12) an unpractical approach. Limited sampling strategies or predictive systemic drug exposure equation models based on limited sampling times are available only for MMF but lack for EC-MPS. METHODS The present study enrolled 26 kidney transplant recipients receiving EC-MPS as part of their immunosuppressive therapy. Twenty-six full MPA AUC(0-12) were performed. By using multiple stepwise regression analysis, we obtained several predictive equations of MPA systemic exposure in this group of patients. The value of the selected equations was tested in a subsequently enrolled group of 26 kidney transplant recipients. RESULTS The best equations obtained in the first group of patients were the following: 22.906 + 3.880·C(0) + 1.117·C(1) + 7.527·C(8) (r = 0.901) and 35.064 +3.784·C(0) + 1.002·C(1) + 1.192·C(2) (r = 0.846). These equation models showed an optimal agreement between the full AUCs and estimated AUCs by using the validation group of patients. CONCLUSIONS Limited sampling strategies are useful for MPA AUC(0-12) estimation in patients receiving EC-MPS and cyclosporine. The choice of one or the other equation model depends on the pharmacokinetic characteristics of the patients, in particular the potential presence of enterohepatic recirculation.

EC-MPS permits lower gastrointestinal symptom burden despite higher MPA exposure in patients with severe MMF-related gastrointestinal side-effects

Gastrointestinal (GI) adverse events in renal transplant patients are a common cause of mycophenolate mofetil (MMF) dose reductions, which result in an increased risk of graft rejection because of a low immunosuppression. This study investigated whether conversion from MMF to enteric‐coated mycophenolate sodium (EC‐MPS) in renal transplant patients with serious GI side‐effects, alleviated these symptoms and allowed administration of higher doses of EC‐MPS. Nineteen renal transplant patients with severe MMF‐related GI side‐effects underwent a progressive reduction in MMF dose until symptoms disappeared. At this point, 12‐h AUCMMF was evaluated and patients were shifted to an equimolar dose of EC‐MPS. The EC‐MPS dose was then progressively increased until the highest recommended dose was reached or GI symptoms re‐appeared. Four weeks post‐conversion, AUCEC‐MPS was determined. Conversion led to a mean increase in EC‐MPS dose of 68% (P < 0.0001), with a corresponding rise in AUC0‐12 (60.5%, P < 0.0006) associated with significant benefits in terms of both quality of life (Kidney Transplant Questionnaire, P < 0.01) and GI symptoms (Gastrointestinal Symptom Rating Scale, P < 0.0001), using validated questionnaires. In five of 19 patients, the EC‐MPS dose could not be increased because of the prompt insurgence of GI symptoms. Renal function and biochemical parameters remained stable post‐conversion and no rejection episodes occurred. These findings suggest that, in selected patients, EC‐MPS may be better tolerated than MMF when GI symptoms are particularly important and permits higher mycophenolic acid exposure, when required.

A Pharmacokinetic Interaction Between Clarithromycin and Sirolimus in Kidney Transplant Recipient

Bacterial infection is a frequent event in renal transplant recipients and often requires the use of antimicrobial agents. In this paper it is reported an evidence of pharmacokinetic interaction between clarithromycin and sirolimus in a kidney transplanted woman, suffering from pulmonary infection sustained by a bacterial pathogen, in particular Hemophilus Influenzae. In the present case report, the concomitant administration of clarithromycin and sirolimus determined impressive increase of sirolimus trough blood concentrations from 6.2 up to 54 ng/mL and this increase was associated with an acute impairment of renal function, almost completely reversed upon both drugs discontinuation. This drug-drug interaction is due to a likely inhibition of activity of both cytochrome P450 3A4 and P-glycoprotein. Although this interaction could be predicted, it represents the first reported clinical evidence.

Efficacy of a reduced pill burden on therapeutic adherence to calcineurin inhibitors in renal transplant recipients: an observational study

Purpose The aim of this study was to determine the prevalence of nonadherence in a cohort of renal transplant recipients (RTRs) and to evaluate prospectively whether more intense clinical surveillance and reduced pill number enhanced adherence. Patients and methods The study was carried out in 310 stable RTRs in whom adherence, life satisfaction, and transplant care were evaluated by specific questionnaires (time 0). The patients under tacrolimus (TAC; bis in die [BID]) were then shifted to once-daily TAC (D-TAC) to reduce their pill burden (Shift group) and were followed up for 6 months to reevaluate the same parameters. Patients on cyclosporin or still on BID-TAC constituted a time-control group. Results The prevalence of nonadherence was 23.5% and was associated with previous rejection episodes (P<0.002), and was inversely related to Life Satisfaction Index, anxiety, and low glomerular filtration rate (minimum P<0.03). Nonadherent patients were significantly less satisfied with their medical care and their relationships with the medical staff. A shift from BID-TAC to D-TAC was performed in 121 patients, and the questionnaires were repeated after 3 and 6 months. In the Shift group, a reduction in pill number was observed (P<0.01), associated with improved adherence after 3 and 6 months (+36%, P<0.05 versus basal), with no change in controls. Decreased TAC trough levels after 3 and 6 months (−9%), despite a slight increase in drug dosage (+6.5%), were observed in the Shift group, with no clinical side effects. Conclusion The reduced pill burden improves patients’ compliance to calcineurin-inhibitors, but major efforts in preventing nonadherence are needed.