Acute cellular rejection with isolated v-lesions is not associated with more favorable outcomes than vascular rejection with more tubulointerstitial inflammations.

BACKGROUND: The impact of isolated v-lesions on clinical outcome in biopsies with acute cellular rejection (ACR) is unclear. METHODS: Two hundred and sixty-five biopsies showing the highest ACR severity for each patient were recruited and classified into four groups: (i) acute interstitial rejection (AIR) I with minimal tubulointerstitial inflammation (TI), (ii) AIR II with intensive TI, (iii) acute vascular rejection (AVR) I with minimal TI, and (iv) AVR II with intensive TI. RESULTS: The complete reversal rates of AIR I and AIR II groups were marginally higher than AVR I and AVR II groups (p = 0.16). At eight yr of transplantation, the death-censored graft survival (DCGS) rate of AIR I group (93.3%) was significantly higher compared with the AVR I (72.7%) or AVR II (72.9%) group. AVR I group had a similar DCGS rate with AVR II group (72.7% vs. 74.1%), whereas AVR with v1-lesion showed significantly higher graft survival (GS) rate than those with v2-lesion (70.2% vs. 45.5%). The t-lesion of AIR and v-lesion of AVR group were associated with graft loss. CONCLUSION: The extent of TI is non-specifically associated with graft loss in biopsies with AVR; the higher grade v-lesion predicts the lower complete reversal rate and poorer long-term graft survival.

Donor-specific HLA antibodies in a cohort comparing everolimus with cyclosporine after kidney transplantation.

Donor-specific HLA antibodies (DSA) have a negative impact on kidney graft survival. Therefore, we analyzed the occurrence of DSA and antibody-mediated rejection (AMR) in patients from two prospective randomized trials in our center. At 3-4.5 months posttransplant 127 patients were randomized to continue cyclosporine or converted to everolimus therapy. The presence of DSA was prospectively assessed using Luminex assays. AMR was defined according to the Banff 2009 classification. Antibody screening was available in 126 patients with a median follow-up of 1059 days. Seven out of 65 (10.8%) patients on cyclosporine developed DSA after a median of 991 days. In comparison, 14/61 patients (23.0%) randomized to everolimus developed DSA after 551 days (log-rank: p = 0.048). Eight patients on everolimus compared to two patients on cyclosporine developed AMR (log-rank: p = 0.036). Four of 10 patients with AMR-all in the everolimus group-lost their graft. A multivariate regression model revealed everolimus, >3 mismatches and living donor as significant risk factors for DSA. Acute rejection within the first year, >3 mismatches, everolimus and living donor were independent risk factors for AMR. This single center analysis demonstrates for the first time that everolimus-based immunosuppression is associated with an increased risk for the development of DSA and AMR.

Plasma pharmacokinetics of daptomycin in critically ill patients with renal failure and undergoing CVVHD.

BACKGROUND: Daptomycin is a novel antibiotic with primarily renal elimination. METHODS: In an open-label, prospective trial, the pharmacokinetics of daptomycin after single (8 mg/kg BW) and multiple intravenous doses (4 mg/kg BW) at steady state were determined in critically ill, dialysis-dependent patients treated with continuous veno-venous hemodialysis (CVVHD). Daptomycin levels were determined by HPLC. Subjects with normal renal function received one dose of 4 mg/kg BW of daptomycin. RESULTS: In the normal controls, daptomycin administration resulted in a mean maximum concentration (Cmax) of 60.7 ± 10.7 mg/l and an area under the time-versus-concentration curve from 0 to 24 h (AUC0-24) of 402 ± 56 mg × h/l. In the CVVHD-treated patients, a loading dose of 8 mg/kg lead to Cmax of 87.5 ± 15.0 mg/l, AUC0-24 of 537 ± 97 mg × h/l and AUC24-48 of 193 ± 69 mg × h/l, respectively. After multiple doses of 4 mg/kg every 48 h, Cmax was 41.8 ± 5.0 mg/l, AUC0-24 302 ± 43 mg × h/l and AUC 24-48 h 102 ± 24 mg × h/l, respectively. Approximately 40% of the daptomycin dose administered was removed by CVVHD. Mean plasma half-lives of daptomycin in patients were 2 - 3 times longer than in healthy controls. CONCLUSIONS: The dosing regimen of 4 mg/kg TBW of daptomycin administered to CVVHD patients every 48 h is inappropriate to achieve effective antimicrobial plasma concentrations of daptomycin in the second half of the dosing interval (24 - 48 h). Doses of ≥ 4 mg/kg TBW administered intravenously every 24 h are necessary in CVVHD patients to assure that plasma daptomycin levels are comparably high to subjects with normal renal function and to avoid underdosing.

Effects of transgenic endothelin-2 overexpression on diabetic cardiomyopathy in rats.

BACKGROUND: Transgenic overexpression of human endothelin-2 in rats was used to characterize the contribution of endothelin to diabetic cardiomyopathy. MATERIALS AND METHODS: Diabetes mellitus was induced by streptozotocin in transgenic rats and transgene-negative controls. Nondiabetic animals were included as well to form a 4-group study design. Heart morphological and molecular alterations were analysed following 6 months of hyperglycaemia. RESULTS: Plasma endothelin concentrations were significantly higher in both transgenic groups than in wild-type groups (nondiabetic: 3.5 +/- 0.4 vs. 2.1 +/- 0.2, P < 0.05; diabetic: 4.5 +/- 0.4 vs. 2.5 +/- 0.4 fmol mL(-1), P < 0.01). Diabetes induced cardiac hypertrophy in both wild-type and transgenic rats and showed the highest myocardial interstitial tissue volume density in diabetic transgenic rats (1.5 +/- 0.07%) as compared with nondiabetic transgenic (1.1 +/- 0.03%), nondiabetic wild-type (0.8 +/- 0.01%) and diabetic wild-type rats (1.1 +/- 0.03%; P < 0.01 for all comparisons). A similar pattern with the most severe changes in the enothelin-2 transgenic, diabetic animals was observed for hypertrophy of the large coronary arteries and the small intramyocardial arterioles respectively. Cardiac mRNA expression of endothelin-1, endothelin receptors type A and B were altered in some degree by diabetes or transgenic overexpression of endothelin-2, but not in a uniform manner. Blood pressure did not differ between any of the four groups. CONCLUSIONS: Overexpression of the human endothelin-2 gene in rats aggravates diabetic cardiomyopathy by more severe coronary and intramyocardial vessel hypertrophy and myocardial interstitial fibrosis. This transgenic intervention provides further and independent support for a detrimental, blood pressure-independent role of endothelins in diabetic cardiac changes.

Treatment of PTLD with rituximab and CHOP reduces the risk of renal graft impairment after reduction of immunosuppression.

We addressed the effect of post-transplant lymphoproliferative disorder (PTLD) treatment with rituximab monotherapy or CHOP-based chemotherapy (+/- rituximab) after upfront immunosuppression reduction (IR) on renal graft function in a longitudinal analysis of 58 renal transplant recipients with PTLD and 610 renal transplant controls. Changes in the estimated glomerular filtration rate over time were calculated from a total of 6933 creatinine measurements over a period of >1 year using a linear mixed model with random and fixed effects. Renal graft function significantly improved with treatment of PTLD, especially in the chemotherapy subgroup. Patients treated with IR+chemotherapy +/- rituximab had a noninferior graft function compared with untreated controls suggesting that the negative impact of IR on the renal graft function can be fully compensated by the immunosuppressive effect of CHOP. The immunosuppressive effect of single agent rituximab may partially compensate the negative impact of IR on the graft function. Thus, it is possible to reduce immunosuppression when using chemotherapy to treat PTLD.

Citrate anticoagulation protocol for slow extended hemodialysis with the Genius dialysis system in acute renal failure.

BACKGROUND: The Genius dialysis system is increasingly used as an intermittent hemodialysis device in the setting of acute renal failure. Slow extended hemodialysis is preferred in the case of critical ill patients. In this study we established a safe and feasible citrate anticoagulation protocol for slow extended hemodialysis (SLED) with the Genius system. METHODS: We compared six anticoagulation protocols using SLED in 34 critically ill patients with acute renal failure. One group (A) received only citrate anticoagulation. Four groups (B - D) were treated with citrate and different additional systemic anticoagulation. Patients in the last group (F) were anticoagulated with heparin and were free of citrate anticoagulation. The total number of treatments was 103. A 4% sodium citrate solution was infused into the arterial line of the dialysis device for citrate anticoagulation. The dialysis solution contained one mmol/L of calcium. No additional calcium supplementation was done. We monitored electrolyte, acid-base and cardiovascular status prospectively. RESULTS: Hemodialysis was well tolerated hemodynamically. Electrolytes remained stable throughout hemodialysis in all groups. The decrease in ionized and total calcium was within the expected, clinically acceptable range. Bicarbonate and pH levels increased during dialysis, especially if citrate was used. CONCLUSIONS: Slow extended Genius hemodialysis with citrate is well tolerated and offers a safe and effective alternative to systemic anticoagulation.

Endothelin-1 transgenic mice develop glomerulosclerosis, interstitial fibrosis, and renal cysts but not hypertension.

The human endothelin-1 (ET-1) gene under the control of its natural promoter was transferred into the germline of mice. The transgene was expressed predominantly in the brain, lung, and kidney. Transgene expression was associated with a pathological phenotype manifested by signs such as age-dependent development of renal cysts, interstitial fibrosis of the kidneys, and glomerulosclerosis leading to a progressive decrease in glomerular filtration rate. This pathology developed in spite of only slightly elevated plasma and tissue ET-1 concentrations. Blood pressure was not affected even after the development of an impaired glomerular filtration rate. Therefore, these transgenic lines provide a new blood pressure-independent animal model of ET-1-induced renal pathology leading to renal fibrosis and fatal kidney disease.

Efficacy and safety of intermittent hemodialysis using citrate as anticoagulant: a prospective study.

BACKGROUND: The use of trisodium-citrate for regional anticoagulation of the extracorporal circuit during renal replacement therapy (RRT) has received increased interest, particularly in critically ill patients with increased risk of bleeding. Continuous renal replacement therapies are the most extensively investigated and used procedures in this regard. However, when patients recover from critical illness, RRT is often switched to intermittent procedures. In this prospective study, we investigated the efficacy and safety of citrate anticoagulation during intermittent hemodialysis (IHD) performed with a standard roller blood pump device. METHODS: We treated 11 critically ill patients with acute renal failure. These patients received a total of 31 intermittent IHD treatments. The targeted IHD treatment time was 6 h (4.5 l/h treatment dose). For anticoagulation, a 4% trisodium-citrate solution was continuously infused into the arterial line of the extracorporeal circuit. A calcium-free, lactate-based dialysis solution was used in all treatment procedures. Calcium was continuously substituted via a separate central line. Electrolyte and acid-base changes as well as the cardiovascular hemodynamics were analyzed. RESULTS: All patients achieved the targeted filter life time. Filter clotting did not occur. Electrolytes and acid base values were well-maintained throughout the study period. Particularly metabolic derangements were not observed. All treatments were hemodynamically well-tolerated. CONCLUSIONS: Intermittent hemodialysis with citrate anticoagulation can be safely applied in critically ill patients at high risk of bleeding.

Reduced-exposure cyclosporine is safe and efficacious in de novo renal transplant recipients treated with enteric-coated mycophenolic acid and basiliximab.

BACKGROUND: The lower limit of exposure to calcineurin inhibitors has not yet been established in de novo renal transplant patients receiving mycophenolic acid therapy with basiliximab. METHODS: A 12-month, multicenter, randomized, open-label trial was carried out in which de novo renal transplant patients received enteric-coated mycophenolate sodium, cyclosporine microemulsion, steroids and basiliximab. Patients were randomized to receive standard-exposure (n = 45) or reduced-exposure (n = 44) cyclosporine, based on differing C2 target ranges, after the first month post-transplant. RESULTS: Cyclosporine exposure gradually increased over the first month and was lower than previously recommended. Mean calculated creatinine clearance (primary end-point) was similar in the standard-exposure and reduced-exposure groups at month 6 (55.3+/-3.2 ml/min and 61.5+/-3.7 ml/min respectively, n.s.). There were 4 deaths but no death-censored graft losses, resulting in 95.5% patient and graft survival at one year in both groups. At 6 and 12 months, the incidence of biopsy-proven acute rejection was 17.8% and 17.8% in the standard-exposure group, and 13.6% and 15.9% in the reduced-exposure group. Adverse events were similar between treatment groups. Exploratory analyses could not identify a lower limit for the optimal CsA exposure range, but results suggested that high exposure at one year was associated with deteriorating renal function. CONCLUSIONS: These results indicate that enteric-coated mycophenolate sodium with reduced-exposure cyclosporine, steroids and basiliximab induction has an excellent therapeutic effect and is safe in de novo kidney transplant recipients. Lower C2 targets than previously recommended, particularly early post-transplant, do not appear to be associated with compromised efficacy.

Beta2-microglobulin removal and plasma albumin levels with high cut-off hemodialysis.

PURPOSE: beta2-microglobulin (beta2MG) is pivotal to the pathogenesis of dialysis-related amyloidosis. We compared the effects of high cut-off hemodialysis (HCO-HD) with those of standard high-flux hemodialysis (HF-HD) regarding the concentration and clearance of beta2MG and albumin. DESIGN: We enrolled ten patients with acute renal failure in a double-blind, cross-over, randomized controlled trial. PROCEDURES: Each patient received four hours of HCO-HD (estimated in vivo cutoff 50-60 kDa) and four hours of HF-HD (estimated in vivo cutoff 15-20 kDa) in random order. Statistical methods and outcome measures: As data lacked normal distribution, we used nonparametric statistical analysis. Plasma and dialysate concentrations of beta2MG and albumin were measured at baseline and after four hours of each study treatment. MAIN FINDINGS: We found significantly greater diffusive beta2MG clearances for HCO-HD compared to HF-HD (at the start: 71.8 ml/min vs. 5.1 ml/min; P=0.008 and at the end: 68.8 ml/min vs. 5.7 ml/min; P=0.008). We found a reduction in plasma beta2MG concentrations of -31.6% during HCO-HD compared to an increase by 25.7% during HF-HD; P=0.008. At baseline (HCO-HD: 26.0 g/L vs. HF-HD: 26.5 g/L), and at the end of both treatments, plasma albumin concentrations were comparable (HCO-HD: 25.5 g/L vs. HF-HD: 26.5 g/L; P=0.25). During HCO-HD, albumin clearance was 1.9 ml/min at the start and decreased significantly to 0.8 ml/min at the end; P=0.008. HF-HD had an albumin clearance of 0.01 ml/min. CONCLUSIONS: HCO-HD was more effective in decreasing plasma beta2MG concentrations than standard HF-HD and did not reduce plasma albumin levels. Further studies of HCO-HD in the treatment of dialysis-related beta2MG accumulation appear warranted.

Long-term safety and efficacy after conversion of maintenance renal transplant recipients from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPA, myfortic).

AIM: A 12-month multicenter, double-blind trial in which maintenance renal transplant patients were randomized to remain on mycophenolate mofetil (MMF) or convert to enteric-coated mycophenolate sodium (EC-MPS, myfortic) has demonstrated that conversion from MMF to EC-MPS is safe. Patients completing the study were invited to enter an open-label extension. Upon entry to the extension, patients who had received MMF during the randomized phase were converted to EC-MPS ("newly-exposed EC-MPS" group) and were monitored separately from those who had been randomized to EC-MPS ("long-term EC-MPS" group). The aim of the extension study was to collect long-term safety and efficacy data on EC-MPS, and to confirm the safety of conversion from MMF to EC-MPS in a larger patient population. METHODS: All patients received EC-MPS 720 mg b.i.d. with cyclosporine microemulsion and corticosteroids per local practice. Data derived from the analysis of the first 24 months of the extension phase are presented. RESULTS: Of the 297 patients who completed the core study, 260 (88%) entered the extension; 195 (75%) completed the 24-month extension visit. For on-treatment patients > 95% of the planned daily dose of EC-MPS was administered, and < 13% of patients in both groups had discontinued EC-MPS due to adverse events by 24 months. The overall incidence of adverse events during the extension phase, including infections and hematological abnormalities, was comparable to that seen in the core study, with a similar safety profile in the newly-exposed and long-term EC-MPS groups. There were 3 deaths during the first 24 months of the extension, and 2 graft failures in both the "newly-exposed" and "long-term" EC-MPS groups. CONCLUSIONS: These data demonstrate that long-term use of EC-MPS is effective and has an acceptable tolerability profile in renal transplant patients, and confirm that conversion of maintenance renal transplant patients from MMF to EC-MPS is a safe therapeutic option.

Effect of mycophenolate mofetil monotherapy on T-cell functions and inosine monophosphate dehydrogenase activity in patients undergoing a kidney transplantation.

The aim of this study was to assess the effects of 1 g of mycophenolate mofetil (MMF) on T-cell function and inosine monophosphate dehydrogenase (IMPDH) activity among patients undergoing kidney transplantation. Five patients undergoing renal transplantation from a living donor were enrolled in this study. Compared to baseline (before MMF intake), CD25 and CD71 expression were significantly decreased during the first hour following MMF intake. T-cell proliferation and IMPDH activity also decreased dramatically. Thereafter, all biomarker levels increased over time. At 4 hours, CD25 and CD71 levels, as well as IMPDH activity, returned to almost baseline values, whereas T-cell proliferation remained below baseline. Intracytoplasmic IL-2 expression remained unchanged after MMF ingestions. In conclusion, administration of 1 g of MMF was associated with a transient decrease in CD25 expression in addition to a temporary dramatic decrease in both T-cell proliferation and IMPDH activity.

[Modern immunosuppression following renal transplantation. Standard or tailor made?]. / Moderne Immunsuppressiva nach Nierentransplantation Standard oder massgeschneidert?

Renal transplantation is by far the best therapeutic option for end-stage kidney disease with respect to quality of life, psychosocial rehabilitation, and even patient survival. Optimal immunosuppressive therapy should provide effective prophylaxis of both acute rejection and chronic allograft dysfunction. Thus immunosuppressive therapy should help to maintain good renal function and could help to prevent premature death of the recipient. With the introduction of new immunosuppressants over the last decade a dramatic reduction of acute rejection rates from approximately 50% to 15-30% could be achieved. However, the search for novel immunosuppressive drugs continues, drugs which not only lead to effective prevention of acute rejection, but also have an impact on chronic allograft dysfunction and prevent further deterioration of this multifactorial process. Based on a short presentation of the "three signal model" of immunoactivation, the most important mechanisms and characteristics of the presently available immunosuppressants are described. Because the immunosuppressive objectives change over time, a phase-dependent adaptation is necessary. At present, most centers in Germany use an immunosuppressive combination therapy, consisting of a calcineurin inhibitor (CNI; cyclosporine or tacrolimus), a glucocorticoid (prednisolone or methylprednisolone), and mycophenolic acid (MPA), which is eventually combined with an antibody (e.g., IL-2R antibody) for induction. In contrast to the clear situation 10 years ago, highly specialized knowledge is required today with respect to mechanism of action, side effects, and potential interactions. This may enable the physician to adopt patient-oriented optimal immunosuppression. In the near future more individualized treatment options will be employed, which are adapted to the characteristics and side effects of the immunosuppressant, as well as to the characteristics of the donor, the recipient, and the transplanted organ such as immunology and ischemia. Another aspect is the reduction or elimination of some immunosuppressants at the earliest possible time. With new diagnostic and genetic markers the relationship between recipient and transplanted organ will be characterized better in the future and therapy will become more individualized. Altogether, these measures as well as optimized supportive therapy will help to further improve the longevity of the transplanted organ.

Hemodynamic effects of immunoadsorption and subsequent immunoglobulin substitution in dilated cardiomyopathy: three-month results from a randomized study.

OBJECTIVES: The objective of our study was to assess the hemodynamic effects of immunoadsorption (IA) and subsequent immunoglobulin G (IgG) substitution in comparison with the effects of conventional medical treatment in patients with dilated cardiomyopathy (DCM). BACKGROUND: Various circulating cardiac autoantibodies have been detected among patients suffering from DCM. These antibodies are extractable by IA. METHODS: Patients with DCM (n = 18, New York Heart Association III-IV, left ventricular ejection fraction <30%) and who were on stable medication participated in the study. Hemodynamic measurements were performed using a Swan-Ganz thermodilution catheter. The patients were randomly assigned either to the treatment group with IA and subsequent IgG substitution (IA/IgG group, n = 9) or to the control group without IA/IgG (n = 9). In the IA/IgG group, the patients were initially treated in one IA session daily on three consecutive days. After the final IA session, 0.5 g/kg of polyclonal IgG was substituted. At one-month intervals, IA was then repeated for three further courses with one IA session daily on two consecutive days, until the third month. RESULTS: After the first IA course and IgG substitution, cardiac index (CI) increased from 2.1 (+/-0.1) to 2.8 (+/-0.1) L/min/m2 (p < 0.01) and stroke volume index (SVI) increased from 27.8 (+/-2.3) to 36.2 (+/-2.5) ml/m2 (p < 0.01). Systemic vascular resistance (SVR) decreased from 1,428 (+/-74) to 997 (+/-55) dyne x s x cm(-5) (p < 0.01). The improvement in CI, SVI and SVR persisted after three months. In contrast, hemodynamics did not change throughout the three months in the control group. CONCLUSIONS: Immunoadsorption and subsequent IgG substitution improves cardiovascular function in DCM.

Impaired sodium excretion, decreased glomerular filtration rate and elevated blood pressure in endothelin receptor type B deficient rats.

The renal endothelin (ET) system, particularly the ET type B receptor, has been implicated in the regulation of sodium excretion and glomerular filtration rate (GFR). We analyzed kidney morphology and function in a rat strain characterized by complete absence of a functional ETB receptor. Due to Hirschsprung's disease limiting lifetime in these rats, studies were performed in 23-day-old rats. Kidney size and morphology (glomerular and interstitial matrix content, glomerular size and cell density and intrarenal vascular morphology) were normal in ETB-deficient rats. There were also no evidence of altered kidney cell cycle regulation in these rats. GFR was significantly lower, by 72% (P<0.001), in homozygous ETB-deficient rats than in wild-type rats. Fractional sodium excretion was likewise markedly reduced by 84% in homozygous ETB-deficient rats (P<0.001 versus wild-type rats). Treatment with the specific epithelial sodium channel blocker amiloride led to a much higher increase in fractional sodium excretion in ETB-deficient rats (934.2+/-73% in ETB-deficient rats versus 297+/-20% in wild-type rats, expressed as percentage of corresponding placebo treated control; P<0.001). Mean arterial blood pressure was elevated by 7.9 mmHg in homozygous ETB-deficient rats (P<0.05 versus wild-type rats). Our study demonstrates that ETB-deficiency causes early onset kidney dysfunction characterized by a markedly reduced sodium excretion, decreased GFR, and slightly elevated blood pressure. The complete absence of the ETB receptor causes in the kidney--in contrast to the colon--a functional rather than a developmental, neural crest cell dependent disease, since kidney morphology was normal in ETB-deficient rats. The much higher increase in the fractional sodium excretion in ETB-deficient rats after pharmacological blockade of the epithelial sodium channel indicates that the decreased fractional sodium excretion in ETB-deficient rats is most probably due to a lack of the inhibitory property of the ETB receptor on the epithelial sodium channel activity.

Pharmacokinetics of the immunosuppressant everolimus in maintenance renal transplant patients.

The novel macrocyclic immunosuppressant everolimus has been approved for use in renal and heart transplantation. The objective of this randomized, double-blind, placebo-controlled, dose-escalating Phase 1 study was to evaluate the pharmacokinetic profile of different dosing regimens of everolimus. Fifty-four subjects were randomized for 4-weeks treatment with everolimus (n = 44) or placebo (n = 10). Steady state was reached by day 4 of multiple dosing with evidence for dose-proportionality over the dose range tested. Systemic accumulation was 1.6- to 2.2-fold with multiple dosing. Steady-state predose trough concentrations were well correlated with AUC (r = 0.87, p < 0.001). Within-subject coefficients of variation for the tablet formulation ranged from 10-19% and between-subject coefficients from 34-60% for Cmax and AUC. There was no effect of common demographic parameters (age, sex, weight) on variability in steady-state exposure. These results support the clinical use of everolimus in renal transplantation.

Problems of cyclosporine absorption profiling using C2-monitoring.

UNLABELLED: The present study sought to validate the concept of C2 monitoring in 41 de-novo transplant patients treated with microemulsion of cyclosporine, mycophenolatesodium, steroids and basiliximab. RESULTS: After 6 months patient and graft survival was 98%, rejection rate was 19%. In the first week only a few patients achieved the suggested C2 levels (19% > 1500, 50% > 1200 ng/ml) despite an increased cyclosporine (CsA) dose. After 14 days 63% of patients reached C2 > 1500 ng/ml (83% C2 > 1200) despite decreased CsA dose. 35% of patients had intermittent high C0 (> 300) and low C2 (< 800), suggesting poor and/or slow absorption. Most of them suffered from CsA toxicity. There was a significant (p < 0.05) change of absorption as measured by C2/C0 leading to an increase of C2/dose. CONCLUSIONS: C2 monitoring may be useful to better estimate the CsA exposure in individual patients; however our results indicate some limitations of the current concept of C2 monitoring. Despite increase of dosage many patients do not reach the proposed levels. A significant proportion of patients are poor and/or slow absorbers. CsA toxicity may not be detected by C2 monitoring alone. With the use of basiliximab and mycophenolatesodium lower target levels seem to be sufficient.

Differences in reporting of acute rejections between American and European publications of large immunosuppressive trials impair comparability of study results.

This study examined the use of different definitions for acute rejection in recent large multicenter trials performed in America and Europe in order to assess whether systematic differences exist between both scientific cultures. We systematically selected recent publications on multicenter randomized controlled trials, investigating immunosuppressive regimens in de novo kidney transplant recipients. Publications included were classified according to the type of acute rejection reported: group 1 reported no or only one type of rejection rate (biopsy-proven or treated); group 2 reported information on both treated and biopsy-proven rates. Other potential factors (journal's impact-factor, study size) were compared within the subgroups. To determine the rates of treated but not biopsy-proven acute rejections, additional analyses were performed within subgroup 2. The reviewed publications were 24/44 (54.5%) European (E) and 20/44 (45.5%) American (A) origin. Eighteen of 44 publications reported no or only one type of rejection rate (group 1); 26 publications reported treated as well as biopsy-proven rates (group 2). Significantly more European publications reported both treated and biopsy-proven rates (E: 18/24 [75.0%] vs A: 8/20 [40.0%]; P = .019). Group 1 American papers were published in higher-ranked journals than European ones. The rate of blindly treated rejections did not differ significantly (A: 6.13% [range 0% to 12.8%] vs E: 8.43% [range 0% to 16.9%]) and the proportion of blindly treated rejections was slightly lower in American studies (A: 18.5% vs E: 26.5%). Our systematic review showed large discrepancies with a trend to report biopsy-proven rejection rates only in recent years.

Accurate prediction of kidney allograft outcome based on creatinine course in the first 6 months posttransplant.

Most attempts to predict early kidney allograft loss are based on the patient and donor characteristics at baseline. We investigated how the early posttransplant creatinine course compares to baseline information in the prediction of kidney graft failure within the first 4 years after transplantation. Two approaches to create a prediction rule for early graft failure were evaluated. First, the whole data set was analysed using a decision-tree building software. The software, rpart, builds classification or regression models; the resulting models can be represented as binary trees. In the second approach, a Hill-Climbing algorithm was applied to define cut-off values for the median creatinine level and creatinine slope in the period between day 60 and 180 after transplantation. Of the 497 patients available for analysis, 52 (10.5%) experienced an early graft loss (graft loss within the first 4 years after transplantation). From the rpart algorithm, a single decision criterion emerged: Median creatinine value on days 60 to 180 higher than 3.1 mg/dL predicts early graft failure (accuracy 95.2% but sensitivity = 42.3%). In contrast, the Hill-Climbing algorithm delivered a cut-off of 1.8 mg/dL for the median creatinine level and a cut-off of 0.3 mg/dL per month for the creatinine slope (sensitivity = 69.5% and specificity 79.0%). Prediction rules based on median and slope of creatinine levels in the first half year after transplantation allow early identification of patients who are at risk of loosing their graft early after transplantation. These patients may benefit from therapeutic measures tailored for this high-risk setting.

Safety and efficacy after conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium: results of a 1-year extension study.

Enteric-coated mycophenolate sodium (EC-MPS) is an enteric-coated formulation of mycophenolic acid. A 12-month, multicenter, double-blind, randomized clinical study demonstrated that converting maintenance renal transplant patients from mycophenolate mofetil (MMF) to EC-MPS is safe and does not affect efficacy. In an open-label study extension, 130 patients initially randomized to MMF were converted to EC-MPS (newly exposed); 130 initially randomized to EC-MPS continued on EC-MPS (EC-MPS long-term). A composite endpoint of biopsy-proven acute rejection (BPAR), graft loss, or death occurred in 3 (2.3%) newly exposed and 2 (1.5%) EC-MPS long-term patients during the extension phase. One patient died and one lost his graft. BPAR occurred in 3 (2.3%) newly exposed patients and 1 (0.8%) EC-MPS long-term patient. During the first 12 months of the extension phase, incidence and type of adverse events was similar in both groups and comparable to that seen in the core study. Nine cases of malignancy were reported, mainly nonmelanoma skin cancers. EC-MPS dose adjustments for adverse events were required in <12% of patients. At the end of the 12-month extension, 58 (44.6%) and 64 (49.2%) newly exposed and EC-MPS long-term patients, respectively, had reported at least one gastrointestinal adverse event. Mean serum creatinine remained stable at the 12-month visit of the extension study (137 micromol/L in the newly exposed and 142 micromol/L in the EC-MPS long-term groups). The results of this study demonstrate the long-term safety of EC-MPS and reconfirm the safety of converting MMF maintenance renal transplant patients to EC-MPS.