Ronald J. Hené

A randomized double-blind, multicenter plasma concentration controlled study of the safety and efficacy of oral mycophenolate mofetil for the prevention of acute rejection after kidney transplantation.

BACKGROUNDnAdding a fixed dose of 1 g b.i.d. of mycophenolate mofetil (MMF) to an immunosuppressive regimen consisting of cyclosporine and prednisone results in a 50% reduction in the incidence of acute rejection after kidney transplantation. This study was designed to investigate the relationship between pharmacokinetic data (mycophenolic acid area under the curve; MPA AUC) and the prevention of rejection after kidney transplantation.nnnMETHODSnA total of 154 adult recipients of a primary or secondary cadaveric kidney graft were randomly allocated, in this double-blind trial, to receive MMF treatment aimed at three predefined target MPA AUC values (16.1, 32.2, and 60.6 microg x hr/ml). During the first 6 months after transplantation, plasma samples for nine AUCs were collected. After analysis of the samples, a coded dose adjustment advice was generated using a Bayesian algorithm, maintaining the double blinding. Immunosuppressive therapy further consisted of cyclosporine and prednisone. The primary end point of this study was the occurrence of biopsy-proven acute rejection within the 6-month study period.nnnRESULTSnA total of 150 patients were eligible for analysis. Although after day 21, the mean MMF dose was reduced, the mean MPA AUC gradually increased and target MPA AUC values were exceeded in all three groups. The incidences of biopsy-proven acute rejection in the low, intermediate, and high target MPA AUC groups were 14 of 51 (27.5%), 7 of 47 (14.9%), and 6 of 52 (11.5%), respectively. The incidences of premature withdrawal from the study due to adverse events in the three groups were 4 of 51 (7.8%), 11 of 47 (23.4%), and 23 of 52 (44.2%), respectively. Logistic regression analysis showed a highly statistically significant relationship between median ln(MPA AUC) and the occurrence of a biopsy-proven rejection (P<0.001). The logistic regression using median ln(Cpredose) was also statistically significant for this relationship (P=0.01), whereas it was not when using mean MMF dose (P=0.082). In contrast, the logistic regression using mean MMF dose for comparison of patients who successfully completed the study versus patients experiencing premature withdrawal due to adverse events was highly significant (P<0.001), whereas this was not significant when using median ln(Cpredose) (P=0.512) or median ln(MPA AUC) (P=0.434).nnnCONCLUSIONnMPA Cpredose and MPA AUC are significantly related to the incidence of biopsy-proven rejection after kidney transplantation, whereas MMF dose is significantly related to the occurrence of adverse events.

Prevention of relapses in Wegener's granulomatosis by treatment based on antineutrophil cytoplasmic antibody titre

58 patients with biopsy-proven Wegeners granulomatosis (WG) were prospectively screened for clinical evidence of the disease 3-monthly, with antineutrophil cytoplasmic antibody (ANCA) measurements every month. Over 24 months, ANCA rose in 20 patients, 9 of whom were randomly assigned to receive combined 9 and 3 month courses of cyclophosphamide and prednisolone, respectively, at the time of ANCA rise; and 11 patients who were untreated except if there was a clinical relapse. 6 of 11 untreated patients relapsed within 3 months of ANCA rise. 3 of the remaining 5 patients relapsed after 3 months. There were no early or late relapses in patients randomised to treatment. Patients receiving no treatment at the time of ANCA rise took more cyclophosphamide and prednisolone than patients who were treated. Side-effects did not significantly differ between the two groups.

Effect of cyclosporine on mycophenolic acid trough levels in kidney transplant recipients.

BACKGROUNDnTriple drug treatment consisting of mycophenolate mofetil (MMF), in a standard dose of 2 g daily, combined with cyclosporine (CsA) and prednisone, has become the standard immunosuppressive regimen after kidney transplantation in many centers. The need for therapeutic drug monitoring of mycophenolic acid (MPA) has not yet been established. Several drug interactions with MMF are known. We investigated the influence of CsA withdrawal on MPA trough levels in renal transplant patients.nnnMETHODSnFifty-two patients were treated with 1 g of MMF twice daily, and prednisone and CsA targeted between 125 and 175 ng/ml for 6 months after transplantation. At 6 months after transplantation, 19 patients were randomized for continuation of triple therapy (group A), 19 patients discontinued CsA (group B), and 14 patients discontinued prednisone (group C). We compared 12-hr fasted MPA trough levels at 6 and 9 months after transplantation within and between these groups.nnnRESULTSnMPA trough levels during treatment with CsA, MMF, and prednisone were significantly lower than those during treatment with MMF and prednisone only (group B); median levels were 1.87 mg/L (range: 0.56-5.27) vs. 3.16 mg/L (range: 0.32-7.78), respectively (P=0.002). MPA trough levels in groups A and C did not change between 6 and 9 months after transplantation; group A median levels were 1.87 (range: 0.31-4.32) vs. 1.53 mg/L (range: 0.36-3.70), and group C median levels were 1.62 (range: 0.69-10.34) vs. 1.79 mg/L (range: 0.54-6.00), respectively. At 9 months after transplantation, patients in whom CsA was discontinued had higher MPA trough levels as compared with patients who continued the use of triple therapy (P=0.001) or patients in whom steroids were withdrawn (P=0.014).nnnCONCLUSIONnA significant increase of MPA trough levels was found after discontinuation of CsA (6 months after transplantation), resulting in almost a doubling of MPA trough levels at 9 months after transplantation. This resulted in increased MPA levels in patients without CsA as compared to MPA levels in patients continuing triple therapy or discontinuing prednisone.

Withdrawal of Cyclosporine or Prednisone Six Months after Kidney Transplantation in Patients on Triple Drug Therapy: A Randomized, Prospective, Multicenter Study

Uncertainty exists regarding the necessity of continuing triple therapy consisting of mycophenolate mofetil (MMF), cyclosporine (CsA), and prednisone (Pred) after kidney transplantation (RTx). At 6 mo after RTx, 212 patients were randomized to stop CsA (n = 63), stop Pred (n = 76), or continue triple drug therapy (n = 73). The MMF dose was 1000 mg twice daily, target CsA trough levels were 150 ng/ml, and Pred dose was 0.10 mg/kg per d. Follow-up was until 24 mo after RTx. Biopsy-proven acute rejection occurred in 14 (22%) of 63 patients after CsA withdrawal compared with 3 (4%) of 76 in the Pred withdrawal group (P = 0.001) and 1 (1.4%) of 73 in the control group (P = 0.0001). Biopsy-proven chronic rejection was present in one patient in the control group, in nine patients after CsA withdrawal (P = 0.006 versus control group); and in four patients after discontinuation of Pred (NS). Graft loss occurred in two versus one patient after CsA or Pred withdrawal, respectively, and in two patients in the control group (NS). Patients who successfully withdrew CsA had a significantly lower serum creatinine during follow-up. Pred withdrawal resulted in a reduction in mean arterial pressure, and the total cholesterol/HDL ratio increased. In conclusion, rapid CsA withdrawal at 6 mo after RTx results in a significantly increased incidence of biopsy-proven acute and chronic rejection. Pred withdrawal was safe and resulted in a reduction in mean arterial pressure. However, patient and graft survival and renal function 2 yr after RTx were not different among groups.

Pretransplant Donor-Specific HLA Class-I and -II Antibodies Are Associated With an Increased Risk for Kidney Graft Failure

Pretransplant risk assessment of graft failure is important for donor selection and choice of immunosuppressive treatment. We examined the relation between kidney graft failure and presence of IgG donor specific HLA antibodies (DSA) or C1q‐fixing DSA, detected by single antigen bead array (SAB) in pretransplant sera from 837 transplantations. IgG‐DSA were found in 290 (35%) sera, whereas only 30 (4%) sera had C1q‐fixing DSA. Patients with both class‐I plus ‐II DSA had a 10 yr graft survival of 30% versus 72% in patients without HLA antibodies (p < 0.001). No significant difference was observed in graft survival between patients with or without C1q‐fixing DSA. Direct comparison of both assays showed that high mean fluorescence intensity values on the pan‐IgG SAB assay are generally related to C1q‐fixation. We conclude that the presence of class‐I plus ‐II IgG DSA as detected by SAB in pretransplant sera of crossmatch negative kidney recipients is indicative for an increased risk for graft failure, whereas the clinical significance of C1q‐fixing IgG‐DSA could not be assessed due to their low prevalence.

Oral ulcers in kidney transplant recipients treated with sirolimus and mycophenolate mofetil.

Background. In an attempt to reduce calcineurin inhibitor toxicity, transplant patients treated with tacrolimus can be switched to maintenance treatment with sirolimus. Methods. In a prospective, randomized, multicenter trial, 33 kidney transplant recipients on steroid-free maintenance treatment with tacrolimus and mycophenolate mofetil continued tacrolimus and mycophenolate mofetil (control group, n=18) or were converted from tacrolimus to sirolimus (study group, n=15) at 1 year after transplantation. Results. The study was prematurely stopped as a result of a cluster of nine patients suffering from painful oral ulcerations in the study group. Oral ulcerations did not occur in the control group. The authors here report on the individual cases suffering from this side effect of the instituted immunosuppressive regimen. Conclusions. The authors review the literature with respect to the occurrence of oral ulcers associated with the use of sirolimus or mycophenolate mofetil and speculate on the causes of the high incidence of oral ulcers in their study group. Possible explanations are overimmunosuppression during the period of the conversion from tacrolimus to sirolimus without antiviral prophylaxis, the use of the oral emulsion instead of tablets, or the lack of corticosteroid co-administration.

The influence of obesity on short- and long-term graft and patient survival after renal transplantation

To determine short‐ and long‐term patient and graft survival in obese [body mass index (BMI)u2003≥u200330u2003kg/m2] and nonobese (BMIu2003<u200330u2003kg/m2) renal transplant patients we retrospectively analyzed our national‐database. Patients 18u2003years or older receiving a primary transplant after 1993 were included. A total of 1871 patients were included in the nonobese group and 196 in the obese group. In the obese group there were significantly more females (52% vs. 38.6%, Pu2003<u20030.01) and patients were significantly older [52u2003years (43–59) vs. 48u2003years (37–58); Pu2003<u20030.05]. Patient survival and graft survival were significantly decreased in obese renal transplant recipients (1 and 5u2003year patient survival were respectively 94% vs. 97% and 81% vs. 89%, Pu2003<u20030.01; 1 and 5u2003year graft survival were respectively 86% vs. 92% and 71% vs. 80%, Pu2003<u20030.01). Initial BMI was an independent predictor for patient death and graft failure. This large retrospective study shows that both graft and patient survival are significantly lower in obese renal transplant recipients.

Kidneys from Donors after Cardiac Death Provide Survival Benefit

The continuing shortage of kidneys for transplantation requires major efforts to expand the donor pool. Donation after cardiac death (DCD) increases the number of available kidneys, but it is unknown whether patients who receive a DCD kidney live longer than patients who remain on dialysis and wait for a conventional kidney from a brain-dead donor (DBD). This observational cohort study included all 2575 patients who were registered on the Dutch waiting list for a first kidney transplant between January 1, 1999, and December 31, 2004. From listing until the earliest of death, living-donor kidney transplantation, or December 31, 2005, 459 patients received a DCD transplant and 680 patients received a DBD transplant. Graft failure during the first 3 months after transplantation was twice as likely for DCD kidneys than DBD kidneys (12 versus 6.3%; P=0.001). Standard-criteria DCD transplantation associated with a 56% reduced risk for mortality (hazard ratio 0.44; 95% confidence interval 0.24 to 0.80) compared with continuing on dialysis and awaiting a standard-criteria DBD kidney. This reduction in mortality translates into 2.4-month additional expected lifetime during the first 4 years after transplantation for recipients of DCD kidneys compared with patients who await a DBD kidney. In summary, standard-criteria DCD kidney transplantation associates with increased survival of patients who have ESRD and are on the transplant waiting list.

Everolimus plus early tacrolimus minimization: a phase III, randomized, open-label, multicentre trial in renal transplantation

There is increasing interest in tacrolimus‐minimization regimens. ASSET was an open‐label, randomized, 12‐month study of everolimus plus tacrolimus in de‐novo renal‐transplant recipients. Everolimus trough targets were 3–8u2003ng/ml throughout the study. Tacrolimus trough targets were 4–7u2003ng/ml during the first 3u2003months and 1.5–3u2003ng/ml (nu2003=u2003107) or 4–7u2003ng/ml (nu2003=u2003117) from Month 4. All patients received basiliximab induction and corticosteroids. The primary objective was to demonstrate superior estimated glomerular filtration rate (eGFR; MDRD‐4) at Month 12 in the tacrolimus 1.5–3u2003ng/ml versus the 4–7u2003ng/ml group. Secondary endpoints included incidence of biopsy‐proven acute rejection (BPAR; Months 4–12) and serious adverse events (SAEs; Months 0–12). Statistical significance was not achieved for the primary endpoint (mean eGFR: 57.1 vs. 51.7u2003ml/min/1.73u2003m2), potentially due to overlapping of achieved tacrolimus exposure levels (Month 12 meanu2003±u2003SD, tacrolimus 1.5–3u2003ng/ml: 3.4u2003±u20031.4; tacrolimus 4–7u2003ng/ml: 5.5u2003±u20032.0u2003ng/ml). BPAR (months 4–12) and SAE rates were comparable between groups (2.7% vs. 1.1% and 58.7% vs. 51.3%; respectively). Everolimus‐facilitated tacrolimus minimization, to levels lower than previously investigated, achieved good renal function, low BPAR and graft‐loss rates, and an acceptable safety profile in renal transplantation over 12u2003months although statistically superior renal function of the 1.5–3u2003ng/ml tacrolimus group was not achieved. (ClinicalTrials.gov: NCT00369161) is registered at http://www.clinicaltrials.gov.

The significance of pretransplant donor‐specific antibodies reactive with intact or denatured human leucocyte antigen in kidney transplantation

Antibodies recognizing denatured human leucocyte antigen (HLA) can co‐react with epitopes on intact HLA or recognize cryptic epitopes which are normally unaccessible to HLA antibodies. Their specificity cannot be distinguished by single antigen beads (SAB) alone, as they carry a mixture of intact and denatured HLA. In this study, we selected pretransplant sera containing donor‐specific HLA class I antibodies (DSA) according to regular SAB analysis from 156 kidney transplant recipients. These sera were analysed using a SAB preparation (iBeads) which is largely devoid of denatured HLA class I, and SAB coated with denatured HLA class I antigens. A total of 241 class I DSA were found by regular SAB analysis, of which 152 (63%) were also found by iBeads, whereas 28 (11%) were caused by reactivity with denatured DNA. Patients with DSA defined either by regular SAB or iBeads showed a significantly lower graft survival rate (Pu2009=u20090·007) compared to those without HLA class I DSA, whereas reactivity to exclusively denatured HLA was not associated with decreased graft survival. In addition, DSA defined by reactivity to class I SAB or class I iBeads occurred more frequently in female patients and in patients with historic HLA sensitization, whereas reactivity to denatured HLA class I was not associated with any of these parameters. Our data suggest that pretransplant donor‐specific antibodies against denatured HLA are clinically irrelevant in patients already sensitized against intact HLA.