Recurrent IgA nephropathy is predicted by altered glycosylated IgA, autoantibodies and soluble CD89 complexes.

IgA nephropathy (IgAN), the most common primary glomerulonephritis worldwide, frequently leads to end-stage renal disease and kidney transplantation. However, disease recurrence often occurs after transplantation. Here we evaluated the predictive value of three markers for IgAN recurrence: the presence of galactose-deficient IgA1, IgG anti-IgA autoantibodies, and IgA-soluble (s) CD89 complexes. This was analyzed in 38 kidney transplant recipients with IgAN recurrence and compared with 22 patients transplanted for IgAN but without recurrence and with 17 healthy controls. Pre-transplantation galactose-deficient IgA1 serum levels were significantly higher in the recurrence compared with the no recurrence or control groups. IgA-IgG complexes were significantly elevated in the recurrence group. Both the recurrence and no recurrence groups had increased values of IgA-sCD89 complexes compared with healthy controls, but values were significantly lower in patients with recurrence compared with no recurrence. Areas under the receiver operating curve of the markers in pre-transplantation sera were 0.86 for galactose-deficient-IgA, 0.82 for IgA-IgG, and 0.78 for sCD89-IgA; all significant. Disease recurrence was associated with decreased serum galactose-deficient IgA1 and appearance of mesangial-galactose-deficient IgA1 deposits, whereas increased serum IgA-sCD89 complexes were associated with mesangial sCD89 deposits. Thus, galactose-deficient-IgA1, IgG autoantibodies, and IgA-sCD89 complexes are valuable biomarkers to predict disease recurrence, highlighting major pathogenic mechanisms in IgAN.

Progression of pulse pressure in kidney recipients durably exposed to CsA is a risk factor for epithelial phenotypic changes: an ancillary study of the CONCEPT trial.

In this ancillary study of the CONCEPT trial, we studied the role of CsA withdrawal at 3 months (3M) post-transplant on the intensity of epithelial phenotypic changes (EPC, an early marker for kidney fibrogenesis) on the 12 M surveillance biopsy. Although conversion from CsA to sirolimus (SRL) at 3M was reported to have improved mean graft function at 12 M, it did not reduce the score of EPC (1.73 ± 1.15 in the SRL group vs. 1.87 ± 1 in the CsA group, P = 0.61). Acute rejection, which had occurred twice more frequently in SRL-converted patients included here, was associated with 12 M EPC. Interestingly, we observed that the patients durably exposed to CsA and who developed 12 M EPC had a significant progression of blood pulse pressure (pp) from 1 to 6M post-transplantation (Δpp = +12.3 mmHg, P = 0.0035). Pulse pressure at 4, 6, and 9 M and pp progression from 1 to 6M were significantly associated with the development of EPC at 12 M in renal grafts. Logistic regression analysis revealed that a high 6M pp (≥ 60 mmHg) was an independent risk factor for 12 M EPC with an odds ratio of 2.25 per additional 10 mmHg pp (95%CI: 1.14-4.4, P = 0.02) after adjustment with recipient's and donor's age, acute rejection incidence and immunosuppressive regimen. A post hoc analysis of the data collected in the whole population CONCEPT study revealed that pp was significantly higher at 6 months in patients maintained on CsA and that at this time point pp correlated negatively with GFR at 1 year.

Microbiological diagnosis of severe diarrhea in kidney transplant recipients by use of multiplex PCR assays.

Diarrhea is a frequent complication after kidney transplantation, ascribed to adverse effects of the immunosuppressive therapy in case of negative microbiological examination of the stools. The aim of this study was to improve the microbiological diagnosis by implementing molecular tests. Fifty-four severe diarrhea events that occurred in 49 adult kidney transplant recipients from September 2010 to November 2011 were investigated. One or several enteric pathogens were detected in 13 (23%) stool samples using classical microbiological methods versus 39 (72%) for the seven commercially available multiplex PCR assays used retrospectively (P = 0.006). Interestingly, molecular diagnosis identified 15 multiple infections compared to none using classical techniques. The primary pathogens detected were enteropathogenic Escherichia coli (EPEC) (n = 15; 38%), Campylobacter spp. (n = 15; 38%), and Norovirus (n = 14; 36%). Specificities for Campylobacter and Norovirus infection diagnosis were 75 and 100%, respectively, by comparison to reference methods. Based on molecular findings, a cyclosporine-mycophenolate mofetil combination was identified as a risk factor for developing Norovirus-induced diarrhea. Norovirus infections were also responsible for higher weight loss than all the other causes of diarrhea. In samples from asymptomatic immunocompromised and immunocompetent patients, EPEC but not Norovirus and Campylobacter infections were detected at a frequency similar to that observed in symptomatic kidney transplant recipients. In conclusion, molecular tools significantly improved the detection of single and multiple enteric infections by comparison to classical techniques and could quickly become the key element in the management of severe acute diarrhea in transplant recipients.

Frequent occurrence of parvovirus B19 DNAemia in the first year after kidney transplantation.

Described for the first time in 1986, Parvovirus B19 (B19V) infection in kidney transplant recipients remains little-known and probably underestimated. The aims of this study were to establish B19V infection frequency during the first year after kidney transplant and to determine predisposing factors and manifestations of the infection in renal transplant recipients. Sixty consecutive adult patients, transplanted less than a year before, were included in this study. B19V and other opportunistic viral infections were detected retrospectively in plasma samples collected every 15 days during the first 3 months and every month from 3 months to 1 year following the kidney transplant. Demographic characteristics, immunosuppressive treatment and biological findings were recorded on each sampling date. Six patients (10%) presented B19V viremia, while eight CMV (13.3%), seven EBV (11.7%), five HHV-6 (8.3%), five BKV (8.3%), and two adenovirus (3.3%) infections were detected. The mean value of B19V viral load was 149 UI/ml. B19V infections were either reactivation or reinfection due to genotype two in five cases, while one case of primary infection with genotype 1 was observed. Neither risk factors nor biological consequences of B19V infection have been identified. These results rank B19V third among opportunistic viral infections occurring during the first year after a kidney transplant. With regard to this high incidence, and even if the risk factors and biological consequences of the infection should be assessed in larger studies, the question of systematic screening and follow-up of B19V infection in kidney transplant recipients is relevant.

Correction of postkidney transplant anemia reduces progression of allograft nephropathy.

Retrospective studies suggest that chronic allograft nephropathy might progress more rapidly in patients with post-transplant anemia, but whether correction of anemia improves renal outcomes is unknown. An open-label, multicenter, randomized controlled trial investigated the effect of epoetin-ß to normalize hemoglobin values (13.0-15.0 g/dl, n=63) compared with partial correction of anemia (10.5-11.5 g/dl, n=62) on progression of nephropathy in transplant recipients with hemoglobin <11.5 g/dl and an estimated creatinine clearance (eCrCl) <50 ml/min per 1.73 m(2). After 2 years, the mean hemoglobin was 12.9 and 11.3 g/dl in the normalization and partial correction groups, respectively (P<0.001). From baseline to year 2, the eCrCl decreased by a mean 2.4 ml/min per 1.73 m(2) in the normalization group compared with 5.9 ml/min per 1.73 m(2) in the partial correction group (P=0.03). Furthermore, fewer patients in the normalization group progressed to ESRD (3 versus 13, P<0.01). Cumulative death-censored graft survival was 95% and 80% in the normalization and partial correction groups, respectively (P<0.01). Complete correction was associated with a significant improvement in quality of life at 6 and 12 months. The number of cardiovascular events was low and similar between groups. In conclusion, this prospective study suggests that targeting hemoglobin values ≥13 g/dl reduces progression of chronic allograft nephropathy in kidney transplant recipients.

Steroid avoidance with early intensified dosing of enteric-coated mycophenolate sodium: a randomized multicentre trial in kidney transplant recipients.

BACKGROUND: Short-term intensified dosing using enteric-coated mycophenolate sodium (EC-MPS) reduces rejection after kidney transplantation without compromising safety and may facilitate steroid avoidance. METHODS: In a 6-month, multicentre open-label trial, 222 de novo kidney transplant recipients at low-immunological risk were randomized to steroid avoidance or maintenance steroids with interleukin (IL)-2 receptor antibody (IL-2RA) induction, EC-MPS (2160 mg/day to Week 6, 1440 mg/day thereafter) and cyclosporine. RESULTS: The primary end point; treatment failure at Month 6 [biopsy-proven acute rejection (BPAR), graft loss, death or loss to follow-up], occurred in 17.9% (20/112) of steroid-avoidance patients and 14.5% (16/110) of controls (difference 3.4%, 95% confidence interval -6.3 to 13.1, P = 0.47 for superiority testing). BPAR occurred in 11.6 and 7.3% of patients in the steroid-avoidance and control arms, respectively (P = 0.27). Creatinine clearance was similar at Month 6 (steroid-avoidance 56 ± 18 mL/min/1.73 m(2), controls 60 ± 22 mL/min/1.73 m(2), P = 0.34). Cytomegalovirus infection, as reported by investigators, occurred in 12.5% of steroid-avoidance patients and 22.7% of controls (P = 0.045). CONCLUSIONS: A regimen of early intensified EC-MPS dosing with calcineurin inhibitor and IL-2RA induction permits oral steroid avoidance in adult kidney transplant patients at low-immunological risk without compromising efficacy at 6 months' follow-up.

Impact of pre-transplant dialysis modality on post-transplant diabetes mellitus after kidney transplantation.

Post-transplant diabetes mellitus (PTDM) is a well-known complication in renal transplant recipients (RTRs). While a number of risk factors for PTDM have been identified, the potential impact of pre-transplant dialysis modality on subsequent development of PTDM has not yet been explored. We performed a multicenter retrospective study on 2010 consecutive RTRs who did not have a history of diabetes prior to renal transplantation. PTDM was defined as a need for anti-diabetic therapy in an RTR without a history of diabetes prior to transplantation. Analysis of the risk factors for development of PTDM was performed with respect to pre-transplant dialysis modality. A total of 137 (6.8%) patients developed PTDM; 7% in the hemodialysis group and 6.5% in the peritoneal dialysis (PD) group (p = 0.85). In the multivariate analysis, age (p < 0.001), body mass index (BMI) (p < 0.001), use of tacrolimus (p = 0.002), and rejection episodes (p < 0.001) were identified as independent risk factors for development of PTDM. Patients in the PD group were younger (p = 0.004), had lower BMI (p = 0.07), and were less likely to have a history of hepatitis C (p = 0.007) and autosomal dominant polycystic kidney disease (p = 0.07). Adjustment for these variables did not modify the results. The results of this study suggest that pre-transplant dialysis modality does not have an impact on the subsequent development of PTDM in RTRs.

A 50% reduction in cyclosporine exposure in stable renal transplant recipients: renal function benefits.

BACKGROUND: Although cyclosporine maintenance therapy reduces the risk of acute rejection and increases short-term graft survival in renal transplant recipients, its associated nephrotoxicity increases the risk of chronic graft dysfunction. The dose that allows an optimal risk-to-benefit ratio has not been established. METHODS: This multicentre study enrolled stable renal allograft recipients receiving cyclosporine and mycophenolate mofetil without corticosteroids in their second year post-transplant. Patients were randomized to a cyclosporine dose targeted to a standard area under the concentration-time curve (AUC)(0-12 h) (usual exposure, n = 104) or 50% of the study standard AUC(0-12 h) (low exposure, n = 108) using a three-point pharmacokinetic sampling. The primary endpoint was the percentage of patients with treatment failure at 24 months (graft loss/acute rejection/nephrotoxicity/>15% serum creatinine level increase). RESULTS: Treatment failure was reported in 37 out of 101 (37%) patients in the usual-exposure and 19 out of 106 (18%) patients in the low-exposure groups (P = 0.003). Mean estimated glomerular filtration rate decreased from baseline to 2 years with usual exposure and increased with low exposure (P < 0.001). Mean systolic and diastolic blood pressures were lower with low exposure (P = 0.03 and P = 0.008, respectively). CONCLUSION: In renal transplant recipients receiving maintenance therapy without corticosteroids, a minimization strategy using three-point pharmacokinetic sampling to reduce and maintain cyclosporine exposure to 50% of the usual levels is safe and reduces the risk of graft dysfunction.

Efficacy and safety of de novo or early everolimus with low cyclosporine in deceased-donor kidney transplant recipients at specified risk of delayed graft function: 12-month results of a randomized, multicenter trial.

Immediate or early use of proliferation signal inhibitor (PSI)/mammalian target of rapamycin (mTOR) inhibitor therapy can avoid high exposure to calcineurin inhibitors but concerns exist relating to the risk of delayed graft function (DGF) and impaired wound healing with the mTOR sirolimus. CALLISTO was a 12-month, prospective, multicenter, open-label study. Deceased-donor kidney transplant patients at protocol-specified risk of DGF were randomized to start everolimus on day 1 (immediate everolimus, IE; n = 65) or week 5 (delayed everolimus, DE; n = 74). Incidence of the primary endpoint (biopsy-proven acute rejection, BPAR; graft loss, death, DGF, wound healing complications related to transplant surgery or loss to follow-up) was 64.6% and 66.2% in the IE and DE groups, respectively, at month 12 (P = 0.860). The overall incidence of BPAR was 20.1%. Median estimated glomerular filtration rate was 48 ml/min/1.73 m(2) and 49 ml/min/1.73 m(2) in the IE and DE groups, respectively, at month 12. DGF and wound healing complications were similar between groups. Adverse events led to study drug discontinuation in 17 IE patients (26.2%) and 28 DE patients (37.8%) (NS). In conclusion, introduction of everolimus immediately or early posttransplant in DGF-risk patients is associated with good efficacy, renal function and safety profile. There seems no benefit in delaying initiation of everolimus.

Effect of the shipment of cadaveric renal allografts on allograft survival.

BACKGROUND: Since 1996, the allocation of grafts in France has been based on a hierarchical three-level system: national, regional and local. The objective of this study was to determine whether the shipment of cadaveric kidneys according to these new exchange rules affects allograft outcome in the Eastern region of France. METHODS: This retrospective study analysed all renal transplants performed in the four centres of the French Eastern region during 3 years (1996 to 1998). All patients were followed up until death, return to dialysis, last information date or the end of June 2003. Information regarding the donors, recipients and treatments, as well as patient and graft outcome, was recorded. Factors associated with graft loss were analysed using Cox proportional hazard methods. RESULTS: 542 transplants were analysed, 287 (53%) kidneys were transplanted locally, 229 (42.2%) kidneys coming from exchanges within the region and 26 (4.8%) from another region. There were statistically significant differences between the four centres for donors' and recipient' characteristics and for immunosuppressive treatment, but there was no difference between centres regarding patient survival (94.4% at 5 years), graft survival (83.7% at 5 years) or death-censored graft survival (87.8% at 5 years). Compared to locally transplanted grafts, shipped grafts had significantly better human leukocyte antigen (HLA) matching (2.5 +/- 1.3 versus 2.1 +/- 1.0 matches, P = 0.0005 but a longer cold ischaemia time (23.2 +/- 7.9 versus 19.2 +/- 7.8 h, P < 0.0001). Three independent factors were associated with a reduced graft survival: at least one acute rejection, delayed graft function and a shipped graft. CONCLUSION: The results of this study suggest that the shipment of cadaveric renal allografts in a regional distribution system is associated with better HLA matching but is a significant predictor of graft loss at 5 years. It would be advisable to restrict graft sharing to patients whose access to transplantation is limited, taking special care to avoid any additional factors having a detrimental effect on the outcome.

CMV infections after two doses of daclizumab versus thymoglobulin in renal transplant patients receiving mycophenolate mofetil, steroids and delayed cyclosporine A.

BACKGROUND: Cytomegalovirus (CMV) infection is a major complication after renal transplantation and is involved in graft rejection. The anti-interleukin-2-receptor antibody daclizumab reduces the incidence of acute rejection without increasing the incidence of CMV infection. METHODS: This multicentre, randomized trial compared safety and efficacy, at 1 year, of two doses of daclizumab (54 patients, group D) with thymoglobulin (55 patients, group T) plus delayed cyclosporine (CsA), MMF (mycophenolate mofetil) and steroids in first cadaver kidney transplant patients. Primary criterion was CMV infection/syndrome/disease. D+/R- patients received oral ganciclovir prophylaxis for 90 days. RESULTS: Status for CMV was identical in the both groups. The incidence of CMV infection/syndrome/disease was 39% in group D versus 51% in group T (NS). Time to onset of CMV replication was delayed in group D (P = 0.015) and mean number of pp65-positive cells was lower at 4 and 6 months (P < 0.001). Incidence of symptomatic CMV episodes was not reduced in whole group D (5.6% versus 16.4%, NS), but lower in D+/R+ and D-/R+ patients without chemoprophylaxis, compared to group T (2.8% versus 21.6%, P = 0.028). Patient and graft survivals and incidence of biopsy-proven acute rejection were identical. CONCLUSIONS: Limited dosing regimen of daclizumab with MMF, steroids and delayed CsA introduction was safe and effective. The incidence of CMV infection was not significantly different, but without chemoprophylaxis, clinical manifestations and viral replication were reduced with this regimen.

Interindividual variability in the concentration-effect relationship of antilymphocyte globulins - a possible influence of FcgammaRIIIa genetic polymorphism.

AIMS: Polyclonal antilymphocyte globulins (ALGs) are currently used in transplantation, but the sources of interindividual variability of their effect are poorly understood. No pharmacokinetic-pharmacodynamic (PK-PD) study of ALG is available. Moreover, the genetic polymorphism of FcgammaRIIIa, a receptor for the Fc portion of immunoglobulins involved in antibody-dependent cellular cytotoxicity (ADCC), may influence their concentration-effect relationship. METHODS: Fourteen kidney transplant patients treated by horse ALG were included in a prospective, noncomparative study. A population two-compartment PK model including a time dependence of the central volume of distribution was developed. Total lymphocyte count was used as biomarker of effect. Concentration-effect data were described using a physiological indirect response model, combining concentration-dependent and -independent inhibitions of lymphocyte input into the circulation. In addition, six kidney transplant patients in whom ALG concentrations were not available were included retrospectively. All patients were genotyped for FCGR3A. RESULTS: Both the PK and the PK-PD model described the data satisfactorily and showed high interindividual variability. Asymptotic T(1/2)-alpha and T(1/2)-beta-values were 1.3 and 25 days, respectively. The concentration of ALG leading to a 50% inhibition of lymphocyte input (IC(50)) was lower in FCGR3A-V carriers than in FCGR3A-F/F patients (383 +/- 199 vs. 593 +/- 209 mg l(-1), P = 0.008). CONCLUSIONS: This is the first description of the ALG effect on lymphocyte count using PK-PD modelling. Our results show that part of the variability in their concentration-effect relationship may be explained by FcgammaRIIIa genetic polymorphism and therefore that horse ALG may deplete lymphocytes by ADCC.

[Incidence and management of anemia in renal transplantation: an observational-French study]. / Incidence et prise en charge de l'anémie en transplantation rénale: une étude observationnelle française.

The management of anemia after kidney transplantation remains poorly explored. The Management of Anemia in French Kidney Transplant Patients (MATRIX) study is an observational study conducted in 10 academic hospitals among kidney-transplant patients designed to evaluate the prevalence, associated factors and management of post-transplant anemia. Over two consecutive weeks, 418 recipients (males: 248; age: 50.8+/-12.7 years) were included, all were transplanted for more than six months. Mean serum creatinine (Scr) was 152+/-67 micromol/l and mean hemoglobin (Hb) was 12.4+/-1.8 g/dl (males: 12.8+/-1.9 g/dl; females 11.9+/-1.6 g/dl). Irrespective of the delay following transplantation, 23% of patients (n=95) were severely anemic (Hb < or = 11 g/dl). Eighteen percent of the patients received an antianemic treatment (10% oral iron, 7% erythropoiesis stimulating agents (ESA), 4% folic acid) and only 35% of the severely anemic patients were actually treated (n=33). A significantly-negative correlation was observed between eGFR and Hb levels (R= -0.347, p<0.02). Ninety-six percent of the 193 patients transplanted for more than six months and a Scr greater than 150 micromol/l (n=185) suffered at least one comorbidity (89% hypertension, 32% hypercholesterolemia, 13% diabetes); this group represent the second cohort. Seventy-four percent of them were treated with mycophenolate mofetil, 16% with azathioprine, and 62% with an ACEI or angiotensin II receptor antagonists. Since the transplantation, 127 patients (66%) have been anemic (Hb < or = 11 g/dl) and 58% (n=112) were treated (iron and/or ESA, respectively 81 and 55%). Among the patients not treated for anemia, 74% had an Hb level below 12g/dl. ESA-treated patients received a mean dose of 8500 UI+/-2800 per week. Anemia is under-diagnosed and under-treated in renal-transplant recipients, despite its high prevalence. As expected, a correlation between renal function and Hb levels was observed, as in CKD patients. Prospective studies are underway to assess the consequences of postkidney transplant anemia on quality of life, cardiovascular morbidity and chronic allograft nephropathy and to define the benefit of the treatment.

CYP3A5*3 influences sirolimus oral clearance in de novo and stable renal transplant recipients.

BACKGROUND: The low and highly variable oral bioavailability of the immunosuppressant sirolimus is thought to result partly from genetic polymorphism of the CYP3A5 gene. METHODS: This study aimed to evaluate the contribution of the CYP3A5 single-nucleotide polymorphism A6986G to the interindividual variability of sirolimus pharmacokinetics in 47 renal transplant patients at steady state, 21 of whom were also followed up for the first 3 months after transplantation. The patients were administered sirolimus, mycophenolate mofetil, and corticosteroids but no calcineurin inhibitor. They were genotyped for CYP3A5*3 by use of real-time quantitative polymerase chain reaction based on the 5'-nuclease allelic discrimination assay. Full sirolimus blood concentration profiles were measured at steady state (3 months after transplantation or more) in all patients, as well as at weeks 1 and 2 and month 1 in 21 of these patients, by use of liquid chromatography-tandem mass spectrometry. The sirolimus area under the concentration-time curve (AUC) was calculated via the standard noncompartmental approach. Maximal concentration (C(max)) and trough level (C(0)) values were measured. RESULTS: Significantly lower AUC/dose, C(max)/dose, and C(0)/dose values were found at steady state (n = 47) in individuals carrying at least 1 CYP3A5*1 allele (n = 6) than in *3/*3 patients (26.6 +/- 15.7 versus 51.1 +/- 21.1 [P = .008], 4.8 +/- 3.3 versus 7.7 +/- 3.3 [P = .02], and 1.5 +/- 0.8 versus 3.0 +/- 1.5 [P = .01], respectively), as well as during all posttransplant periods in the subgroup of 21 patients who were followed up for the first 3 months after transplantation (n = 21) (P < .05 always). Patients with the CYP3A5*1/*1 and *1/*3 genotypes required a significantly higher sirolimus daily dose to achieve the same blood concentration at steady state as *3/*3 patients. In patients followed up for the first 3 months after transplantation, C(0) levels within the target range were only achieved after 1 to 3 months of repeated dosing and dose adjustment in both genotypic groups. CONCLUSION: These results confirm that sirolimus metabolic activity and oral clearance are significantly decreased in patients who are homozygous for the CYP3A5*3 single-nucleotide polymorphism and suggest that the determination of this polymorphism could be useful for a priori dose adjustment of sirolimus, given the long half-life of this drug.

Sirolimus population pharmacokinetic/pharmacogenetic analysis and bayesian modelling in kidney transplant recipients.

OBJECTIVES: The objectives of the present study were: (i) to analyse the population pharmacokinetics of sirolimus in renal transplant recipients co-administered mycophenolate mofetil, but no calcineurin inhibitor over the first 3 months post-transplantation and study the influence of different potential covariates, including genetic polymorphisms of cytochrome P450 (CYP) metabolic enzymes and active transporters, on pharmacokinetic parameters; and (ii) to develop a Bayesian estimator able to reliably estimate the individual pharmacokinetic parameters and exposure indices in this population. METHODS: Twenty-two adult renal transplant patients treated with sirolimus participated in this study. Ninety concentration-time profiles (938 sirolimus whole blood samples) were collected at days 7 and 14, and months 1 and 3 post-transplantation. The population pharmacokinetic study was conducted using the nonlinear mixed effects model software, NONMEM, and validated using both the bootstrap and the cross-validation approaches. Finally, a Bayesian estimator based on a limited sampling strategy was built using the post hoc option. RESULTS: A two-compartment open model with first-order elimination and Erlang's distribution (to describe the absorption phase) best fitted the data. The mean pharmacokinetic parameter estimates were 5.25 h(-1), 218L and 292L for the transfer rate constant, the apparent volume of the central and peripheral compartments, respectively. The CYP3A5*1/*3 polymorphism significantly influenced the apparent oral clearance: mean oral clearance = 14.1 L/h for CYP3A5 non expressers (CYP3A5*3/*3 genotype) versus 28.3 L/h for CYP3A5 expressers (CYP3A5*1/*3 and *1/*1 genotypes). The standard errors of all the parameter estimates were <15%. Maximum a posteriori Bayesian forecasting allowed accurate prediction of sirolimus area under the concentration-time curve from 0 to 24 hours using a combination of only three sampling times (0, 1 and 3 hours post-dose), with a non-significant bias of -2.1% (range -22.2% to +25.9%), and a good precision (root mean square error = 10.3%). This combination is also easy to implement in clinical practice. CONCLUSION: This study presents an accurate population pharmacokinetic model showing the significant influence of the CYP3A5*1/*3 polymorphism on sirolimus apparent oral clearance, and a Bayesian estimator accurately predicting sirolimus pharmacokinetics in patients co-administered mycophenolate mofetil, but no calcineurin inhibitor.

Safety of Eplerenone for Kidney-Transplant Recipients with Impaired Renal Function and Receiving Cyclosporine A.

BACKGROUND: Animal studies have highlighted the role of vascular mineralocorticoid receptor during Cyclosporine A-induced nephrotoxicity. Mineralocorticoid receptor antagonists could improve kidney survival but are not commonly used during renal impairment and in association with several immunosuppressive drugs due to a supposed higher risk of adverse events. We tested the tolerance of eplerenone according to its expected adverse events: hyperkalemia, metabolic acidosis, hypotension, acute kidney failure, or any other adverse event. METHODS: We conducted a single-center, prospective, open-label study in 31 kidney-transplant recipients with impaired renal function (30 and 50 mL/min/1.73 m2) and receiving cyclosporine A. All patients received eplerenone 25 mg/d for 8 weeks. Serum potassium, renal function and expected adverse events were closely monitored. RESULTS: Eight patients experienced mild hyperkalemia (>5 mmol/L), one moderate hyperkalemia (>5.5 mmol/L) and had to receive potassium-exchange resin. No severe hyperkalemia (>6 mmol/L) occurred. One acute kidney failure was observed, secondary to diarrhea. Basal serum potassium and bicarbonate were independently associated with a higher risk of developing mild hyperkalemia (>5 mmol/L) under treatment (OR 6.5, p = 0.003 and 0.7, p = 0.007, respectively). A cut-off value of 4.35 mmol/L for basal serum potassium was the best factor to predict the risk of developing mild hyperkalemia (>5 mmol/L). CONCLUSIONS: Until eGFR falls to 30 mL/min/1.73 m2, eplerenone could be safely given to kidney-transplant recipients receiving cyclosporine A, if kalemia is closely monitored. When renal function is impaired and if basal kalemia is >4.35 mmol/L, then clinicians should properly balance risk and benefit of eplerenone use and offer dietary advice. An adequately powered prospective randomized study is now needed to test its efficiency (and safety) in this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT01834768.

One-year Results of the Effects of Rituximab on Acute Antibody-Mediated Rejection in Renal Transplantation: RITUX ERAH, a Multicenter Double-blind Randomized Placebo-controlled Trial.

BACKGROUND: Treatment of acute antibody-mediated rejection (AMR) is based on a combination of plasma exchange (PE), IVIg, corticosteroids (CS), and rituximab, but the place of rituximab is not clearly specified in the absence of randomized trials. METHODS: In this phase III, multicenter, double-blind, placebo-controlled trial, we randomly assigned patients with biopsy-proven AMR to receive rituximab (375 mg/m) or placebo at day 5. All patients received PE, IVIg, and CS. The primary endpoint was a composite of graft loss or no improvement in renal function at day 12. RESULTS: Among the 38 patients included, at 1 year, no deaths occurred, but 1 graft loss occurred in each group. The primary endpoint frequency was 52.6% (10/19) and 57.9% (11/19) in the rituximab and placebo groups, respectively (P = 0.744). Renal function improved in both groups, as soon as day 12 with no difference in serum creatinine level and proteinuria at 1, 3, 6, and 12 months. Supplementary administration of rituximab and total number of IVIg and PE treatments did not differ between the 2 groups. Both groups showed improved histological features of AMR and Banff scores at 1 and 6 months, with no significant difference between groups but with a trend in favor of the rituximab group. Both groups showed decreased mean fluorescence intensity of donor-specific antibodies as soon as day 12, with no significant difference between them but with a trend in favor of the rituximab group at 12 months. CONCLUSIONS: After 1 year of follow-up, we observed no additional effect of rituximab in patients receiving PE, IVIg, and CS for AMR. Nevertheless, our study was underpowered and important differences between groups may have been missed. Complementary trials with long-term follow-up are needed.

Characteristic pattern of chromosomal imbalances in posttransplantation lymphoproliferative disorders: correlation with histopathological subcategories and EBV status.

BACKGROUND: Posttransplantation lymphoproliferative disorders (PTLDs) are a spectrum of lymphoid proliferations, occurring in immunosuppressed organ transplant recipients. They comprise early lesions, polymorphic (P-PTLD), monomorphic (M-PTLD), and Hodgkin/Hodgkin-like lymphoma PTLD (HL-PTLD) lesions. Most of them are associated with Epstein-Barr virus (EBV). Little is known about their genetic changes. MATERIALS AND METHODS: We have studied 35 PTLDs[7 P-PTLDs (3/7 polyclonal IgH), 26 M-PTLDs (22 B-cell PTLD, 4 T-cell PTLD), 2 HL-PTLDs], using comparative genomic hybridization (CGH), a DNA-based technique allowing a screening of chromosomal imbalances without needing cultured cells. RESULTS.: Overall incidence of chromosomal imbalances: 51.5 %. The most frequent gains involved 8q24, 3q27 [4 cases each]; 2p24p25, 5p, 9q22q34, 11, 12q22q24, 14q32, 17q, 18q21 [2 cases each]. Nonrandom losses were 17p13 [4 cases]; 1p36, 4q [3 cases each]; 17q23q25, Xp [2 cases each]. Three high-level amplifications were detected: 4p16, 9p22p24, 18q21q23. In this latter imbalance, involvement of Bcl2 has been confirmed by FISH. The nonrandom CGH imbalances occurring in M-PTLD are usually described in lymphomas of immunocompetent patients and contain genes known to be involved in lymphomagenesis, while genomic abnormalities detected in half cases of EBV positive P-PTLD are mostly unknown. CONCLUSION: This study reported nonrandom chromosomal imbalances in PTLD and also identified early genomic alterations in EBV positive P-PTLD. These results raise two questions: the role of such lesions in the development and progression of those EBV induced-lymphoproliferations and their clinical significance especially in P-PTLD.

A double absorption-phase model adequately describes mycophenolic acid plasma profiles in de novo renal transplant recipients given oral mycophenolate mofetil.

BACKGROUND: Mycophenolic acid (MPA) shows complex plasma concentration-time profiles, particularly in the immediate (first month) post-transplantation phase for which no relevant pharmacokinetic model has been proposed thus far. OBJECTIVE: The aim of this study was to develop a model to accurately describe the time profile of plasma MPA concentrations after oral administration of mycophenolate mofetil in adult kidney transplant patients, in any post-transplantation period. METHOD: Full interdose pharmacokinetic profiles were collected in 45 adult renal transplant patients who were orally administered mycophenolate mofetil and ciclosporin; 25 patients were de novo transplant patients for whom individual pharmacokinetics were assessed at three post-transplantation periods (days 3, 7 and 30) and 20 patients were stable transplant patients (>3 months post-transplantation). MPA was determined in plasma by liquid chromatography-mass spectrometry. Models combining a single- or double-input (described as single or double gamma distributions) with one- or two-compartments were developed using in-house software and fitted to the individual profiles by nonlinear regression. RESULTS: Visual inspection of the pharmacokinetic profiles showed highly variable absorption profiles and secondary peaks of various intensity. The pharmacokinetic models including a double gamma distribution best fitted these various profiles in the immediate post-transplantation period (mean bias and precision of -0.92% and 20.19%; -1.5% and 18.02%, on day 7 and day 30, respectively), while in the stable post-grafting phase (beyond 3 months), the single- and double-absorption models performed similarly (mean bias and precision of -3.37% and 17.64%; -3.12% and 18.44%, on day 7 and day 30, respectively). CONCLUSION: The proposed pharmacokinetic models adequately describe the concentration-time profiles of MPA in renal transplant patients and could be helpful in the development of tools for MPA monitoring.