Rescue Allocation Modes in Eurotransplant Kidney Transplantation: Recipient Oriented Extended Allocation Versus Competitive Rescue Allocation-A Retrospective Multicenter Outcome Analysis

BACKGROUND

Whenever the kidney standard allocation (SA) algorithms according to the Eurotransplant (ET) Kidney Allocation System or the Eurotransplant Senior Program fail, rescue allocation (RA) is initiated. There are 2 procedurally different modes of RA: recipient oriented extended allocation (REAL) and competitive rescue allocation (CRA). The objective of this study was to evaluate the association of patient survival and graft failure with RA mode and whether or not it varied across the different ET countries.

METHODS

The ET database was retrospectively analyzed for donor and recipient clinical and demographic characteristics in association with graft outcomes of deceased donor renal transplantation (DDRT) across all ET countries and centers from 2014 to 2021 using Cox proportional hazards methods.

RESULTS

Seventeen thousand six hundred seventy-nine renal transplantations were included (SA 15 658 [89%], REAL 860 [4.9%], and CRA 1161 [6.6%]). In CRA, donors were older, cold ischemia times were longer, and HLA matches were worse in comparison with REAL and especially SA. Multivariable analyses showed comparable graft and recipient survival between SA and REAL; however, CRA was associated with shorter graft survival. Germany performed 76% of all DDRTs after REAL and CRA and the latter mode reduced waiting times by up to 2.9 y.

CONCLUSIONS

REAL and CRA are used differently in the ET countries according to national donor rates. Both RA schemes optimize graft utilization, lead to acceptable outcomes, and help to stabilize national DDRT programs, especially in Germany.

Riding the Omicron BA.5 Wave: Improved Humoral Response after Vaccination with Bivalent Omicron BA.4-5-Adapted mRNA SARS-CoV-2 Vaccine in Chronic Hemodialysis Patients

Hemodialysis patients faced an excess morbidity and mortality during the COVID-19 pandemic. We evaluated the effect of second-generation mRNA vaccines against Omicron BA.4 and BA.5 variants of SARS-CoV-2 on humoral immunity. The study population comprised 66 adult hemodialysis patients who have encountered four SARS-CoV-2 antigen contacts through vaccination or infection. We assessed their humoral response using an anti-SARS-CoV-2 spike receptor binding domain IgG antibody assay (S-RBD-ab), measuring neutralizing antibodies against ancestral strain of SARS-CoV-2, Delta, and Omicron in a surrogate virus neutralization test (SVNT), and specifically against BA.5 in a plaque reduction neutralization test (PRNT) before and four weeks after vaccination with Comirnaty Original/Omicron BA.4-5. During the following six months, SARS-CoV-2 infections and symptom severity were documented. The bivalent mRNA vaccine led to a 7.6-fold increase in S-RBD-ab levels and an augmented inhibition of the Omicron variant in SVNT by 35% (median). Seroconversion in the Omicron BA.5-specific PRNT was attained by in 78.4% of previously negative patients (29/37). Levels of S-RBD-ab correlated with inhibition in the Omicron-specific SVNT and neutralization titers in the BA.5-PRNT. Eleven SARS-CoV-2 infections occurred in the six-month follow-up, none of which took a life-threatening course. The bivalent mRNA vaccine improved the SARS-CoV-2 virus variant-specific humoral immunity in chronic hemodialysis patients. Measurement of S-RBD-ab can be used in hemodialysis patients to estimate their humoral immunity status against Omicron BA.5.

Five-year follow-up of a phase I trial of donor-derived modified immune cell infusion in kidney transplantation

Background

The administration of modified immune cells (MIC) before kidney transplantation led to specific immunosuppression against the allogeneic donor and a significant increase in regulatory B lymphocytes. We wondered how this approach affected the continued clinical course of these patients.

Methods

Ten patients from a phase I clinical trial who had received MIC infusions prior to kidney transplantation were retrospectively compared to 15 matched standard-risk recipients. Follow-up was until year five after surgery.

Results

The 10 MIC patients had an excellent clinical course with stable kidney graft function, no donor-specific human leukocyte antigen antibodies (DSA) or acute rejections, and no opportunistic infections. In comparison, a retrospectively matched control group receiving standard immunosuppressive therapy had a higher frequency of DSA (log rank P = 0.046) and more opportunistic infections (log rank P = 0.033). Importantly, MIC patients, and in particular the four patients who had received the highest cell number 7 days before surgery and received low immunosuppression during follow-up, continued to show a lack of anti-donor T lymphocyte reactivity in vitro and high CD19⁺CD24^hiCD38^hi transitional and CD19⁺CD24^hiCD27⁺ memory B lymphocytes until year five after surgery.

Conclusions

MIC infusions together with reduced conventional immunosuppression were associated with good graft function during five years of follow-up, no de novo DSA development and no opportunistic infections. In the future, MIC infusions might contribute to graft protection while reducing the side effects of immunosuppressive therapy. However, this approach needs further validation in direct comparison with prospective controls.

Trial registration

https://clinicaltrials.gov/, identifier NCT02560220 (for the TOL-1 Study). EudraCT Number: 2014-002086-30.

Risk of graft loss in kidney transplant recipients after aortic valve replacement

Surgical aortic valve replacement (SAVR) in kidney transplant recipients (KTR) is associated with high morbidity and mortality, and an increased risk of postoperative graft failure potentially leading to graft loss. Transcatheter aortic valve implantation (TAVI) emerged as an alternative in high-risk patients. However, data on TAVI in kidney transplant recipients are limited. We performed a retrospective analysis of 40 KTR in which aortic valve replacement was performed at our center between 2005 and 2015. The outcomes and follow-up of TAVI (n=20; 2010-2015) and SAVR (n=20; 2005-2015) were analyzed with respect to patient and graft survival. Baseline characteristics in both groups were comparable. Hospital stay after TAVI was significantly shorter compared to SAVR (19 [11.5-21.75] days vs. 33 [21-62] days, p=0.001). Acute graft failure occurred more frequently after SAVR (45% vs. 89.5%; p=0.006). Thirty-day mortality was 10% in both groups. However, in-hospital mortality reached 25% in the SAVR group (TAVI 10%), indicating a more complicated course after surgery. Moreover, during a median follow-up time of 1928 days in TAVI patients and 2717 days in patients after SAVR, graft loss occurred only in the surgically treated group (n=7). While one-year survival after TAVR was 90% compared to 69% after SAVR, long-term follow-up showed comparable results (at 5 years: TAVI 58% vs. 52% SAVR; log-rank-test: p=0.86). In KTR, TAVI can be performed with good mid- to long-term results. Compared to SAVR, renal outcomes seem to be improved after TAVI, suggesting better graft survival.

Individualised immunosuppression with intravenously administered donor-derived modified immune cells compared with standard of care in living donor kidney transplantation (TOL-2 Study): protocol for a multicentre, open-label, phase II, randomised controlled trial

INTRODUCTION

Donor-derived modified immune cells (MIC) induced long-term specific immunosuppression against the allogeneic donor in preclinical models of transplantation. In a phase I clinical trial (TOL-1 Study), MIC treatment resulted in a cellular phenotype that was directly and indirectly suppressive to the recipient's immune system allowing for reduction of conventional immunosuppressive therapy. Here, we describe a protocol for a randomised controlled, multicentre phase-IIb clinical trial of individualised immunosuppression with intravenously administered donor MIC compared with standard-of-care (SoC) in living donor kidney transplantation (TOL-2 Study).

METHODS AND ANALYSIS

Sixty-three living donor kidney transplant recipients from six German transplant centres are randomised 2:1 to treatment with MIC (MIC group, N=42) or no treatment with MIC (control arm, N=21). MIC are manufactured from donor peripheral blood mononuclear cells under Good Manufacturing Practice conditions. The primary objective of this trial is to determine the efficacy of MIC treatment together with reduced conventional immunosuppressive therapy in terms of achieving an operational tolerance-like phenotype compared with SoC 12 months after MIC administration. Key secondary endpoints are the number of patient-relevant infections as well as a composite of biopsy-proven acute rejection, graft loss, graft dysfunction or death. Immunosuppressive therapy of MIC-treated patients is reduced during follow-up under an extended immunological monitoring including human leucocyte antigen-antibody testing, and determination of lymphocyte subsets, for example, regulatory B lymphocytes (Breg) and antidonor T cell response. A Data Safety Monitoring Board has been established to allow an independent assessment of safety and efficacy.

ETHICS AND DISSEMINATION

Ethical approval has been provided by the Ethics Committee of the Medical Faculty of the University of Heidelberg, Heidelberg, Germany (AFmu-580/2021, 17 March 2022) and from the Federal Institute for Vaccines and Biomedicines, Paul-Ehrlich-Institute, Langen, Germany (Vorlage-Nr. 4586/02, 21 March 2022). Written informed consent will be obtained from all patients and respective donors prior to enrolment in the study. The results from the TOL-2 Study will be published in peer-reviewed medical journals and will be presented at symposia and scientific meetings.

TRIAL REGISTRATION NUMBER

NCT05365672.

Modified risk-stratified sequential treatment (subcutaneous rituximab with or without chemotherapy) in B-cell Post-transplant lymphoproliferative disorder (PTLD) after Solid organ transplantation (SOT): the prospective multicentre phase II PTLD-2 trial

The prospective multicentre Phase II PTLD-2 trial (NCT02042391) tested modified risk-stratification in adult SOT recipients with CD20-positive PTLD based on principles established in the PTLD-1 trials: sequential treatment and risk-stratification. After rituximab monotherapy induction, patients in complete remission as well as those in partial remission with IPI < 3 at diagnosis (low-risk) continued with rituximab monotherapy and thus chemotherapy free. Most others (high-risk) received R-CHOP-21. Thoracic SOT recipients who progressed (very-high-risk) received alternating R-CHOP-21 and modified R-DHAOx. The primary endpoint was event-free survival (EFS) in the low-risk group. The PTLD-1 trials provided historical controls. Rituximab was applied subcutaneously. Of 60 patients enrolled, 21 were low-risk, 28 high-risk and 9 very-high-risk. Overall response was 45/48 (94%, 95% CI 83–98). 2-year Kaplan–Meier estimates of time to progression and overall survival were 78% (95% CI 65–90) and 68% (95% CI 55–80) – similar to the PTLD-1 trials. Treatment-related mortality was 4/59 (7%, 95% CI 2–17). In the low-risk group, 2-year EFS was 66% (95% CI 45–86) versus 52% in the historical comparator that received CHOP (p = 0.432). 2-year OS in the low-risk group was 100%. Results with R-CHOP-21 in high-risk patients confirmed previous results. Immunochemotherapy intensification in very-high-risk patients was disappointing.

Impact of Moderna mRNA-1273 Booster Vaccine on Fully Vaccinated High-Risk Chronic Dialysis Patients after Loss of Humoral Response

The long-term effect of protection by two doses of SARS-CoV-2 vaccination in patients receiving chronic intermittent hemodialysis (CIHD) is an urging question. We investigated the humoral and cellular immune response of 42 CIHD patients who had received two doses of SARS-CoV-2 vaccine, and again after a booster vaccine with mRNA-1273 six months later. We measured antibody levels and SARS-CoV-2-specific surrogate neutralizing antibodies (SNA). Functional T cell immune response to vaccination was assessed by quantifying interferon-γ (IFN-γ) and IL-2 secreting T cells specific for SARS-CoV-2 using an ELISpot assay. Our data reveal a moderate immune response after the second dose of vaccination, with significantly decreasing SARS-CoV-2-specific antibody levels and less than half of the study group showed neutralizing antibodies six months afterwards. Booster vaccines increased the humoral response dramatically and led to a response rate of 89.2% for antibody levels and a response rate of 94.6% for SNA. Measurement in a no response/low response (NR/LR) subgroup of our cohort, which differed from the whole group in age and rate of immunosuppressive drugs, indicated failure of a corresponding T cell response after the booster vaccine. We strongly argue in favor of a regular testing of surrogate neutralizing antibodies and consecutive booster vaccinations for CIHD patients to provide a stronger and persistent immunity.

Reduction of immunosuppression combined with whole-brain radiotherapy and concurrent systemic rituximab is an effective yet toxic treatment of primary central nervous system post-transplant lymphoproliferative disorder (pCNS-PTLD): 14 cases from the prospective German PTLD registry

Post-transplant lymphoproliferative disorders (PTLD) exclusively affecting the central nervous system-primary CNS-PTLD (pCNS-PTLD)-are rare. There is no standard therapy, and previous case series have included heterogeneous treatment approaches. We performed a retrospective, multi-centre analysis of 14 patients with pCNS-PTLD after solid organ transplantation (SOT) treated in the prospective German PTLD registry with reduction of immunosuppression (RI), whole-brain radiotherapy (WBRT), and concurrent systemic rituximab between 2001 and 2018. Twelve of fourteen patients were kidney transplant recipients and median age at diagnosis was 65 years. Thirteen of fourteen cases (93%) were monomorphic PTLD of the diffuse large B-cell lymphoma type, and 12/13 were EBV-associated. The median dose of WBRT administered was 40 Gy with a median fraction of 2 Gy. The median number of administered doses of rituximab (375 mg/m²) IV was four. All ten patients evaluated responded to treatment (100%). Median OS was 2.5 years with a 2-year Kaplan-Meier estimate of 63% (95% confidence interval 30-83%) without any recorded relapses after a median follow-up of 2.6 years. Seven of fourteen patients (50%) suffered grade III/IV infections under therapy (fatal in two cases, 14%). During follow-up, imaging demonstrated grey matter changes interpreted as radiation toxicity in 7/10 evaluated patients (70%). The combination of RI, WBRT, and rituximab was an effective yet toxic treatment of pCNS-PTLD in this series of 14 patients. Future treatment approaches in pCNS-PTLD should take into account the significant risk of infections as well as radiation-induced neurotoxicity.

Effect of everolimus-based drug regimens on CMV-specific T-cell functionality after renal transplantation: 12-month ATHENA subcohort-study results

Post-transplant cytomegalovirus (CMV) infections and increased viral replication are associated with CMV-specific T-cell anergy. In the ATHENA-study, de-novo everolimus (EVR) with reduced-exposure tacrolimus (TAC) or cyclosporine (CyA) showed significant benefit in preventing CMV infections in renal transplant recipients as compared to standard TAC + mycophenolic acid (MPA). However, immunomodulatory mechanisms for this effect remain largely unknown. Ninety patients from the ATHENA-study completing the 12-month visit on-treatment (EVR + TAC n = 28; EVR + CyA n = 19; MPA + TAC n = 43) were included in a posthoc analysis. Total lymphocyte subpopulations were quantified. CMV-specific CD4 T cells were determined after stimulation with CMV-antigen, and cytokine-profiles and various T-cell anergy markers were analyzed using flow cytometry. While 25.6% of MPA + TAC-treated patients had CMV-infections, no such events were reported in EVR-treated patients. Absolute numbers of lymphocyte subpopulations were comparable between arms, whereas the percentage of regulatory T cells was significantly higher with EVR + CyA versus MPA + TAC (p = 0.019). Despite similar percentages of CMV-specific T cells, their median expression of CTLA-4 and PD-1 was lower with EVR + TAC (p < 0.05 for both) or EVR + CyA (p = 0.045 for CTLA-4) compared with MPA + TAC. Moreover, mean percentages of multifunctional CMV-specific T cells were higher with EVR + TAC (27.2%) and EVR + CyA (29.4%) than with MPA + TAC (19.0%). In conclusion, EVR-treated patients retained CMV-specific T-cell functionality, which may contribute to enhanced protection against CMV infections.

CD4+ T cell lymphopenia predicts mortality from Pneumocystis pneumonia in kidney transplant patients

BACKGROUND

Pneumocystis jirovecii pneumonia (PcP) remains a life-threatening opportunistic infection after solid organ transplantation, even in the era of Pneumocystis prophylaxis. The association between risk of developing PcP and low CD4⁺ T cell counts has been well established. However, it is unknown whether lymphopenia in the context of post-renal transplant PcP increases the risk of mortality.

METHODS

We carried out a retrospective analysis of a cohort of kidney transplant patients with PcP (n = 49) to determine the risk factors for mortality associated with PcP. We correlated clinical and demographic data with the outcome of the disease. For CD4⁺ T cell counts, we used the Wilcoxon rank sum test for in-hospital mortality and a Cox proportional-hazards regression model for 60-day mortality.

RESULTS

In univariate analyses, high CRP, high neutrophils, CD4⁺ T cell lymphopenia, mechanical ventilation, and high acute kidney injury network stage were associated with in-hospital mortality following presentation with PcP. In a receiver-operator characteristic (ROC) analysis, an optimum cutoff of ≤200 CD4⁺ T cells/µL predicted in-hospital mortality, CD4⁺ T cell lymphopenia remained a risk factor in a Cox regression model.

CONCLUSIONS

Low CD4⁺ T cell count in kidney transplant recipients is a biomarker for disease severity and a risk factor for in-hospital mortality following presentation with PcP.

An open-label, randomized trial indicates that everolimus with tacrolimus or cyclosporine is comparable to standard immunosuppression in de novo kidney transplant patients

This is a randomized trial (ATHENA study) in de novo kidney transplant patients to compare everolimus versus mycophenolic acid (MPA) with similar tacrolimus exposure in both groups, or everolimus with concomitant tacrolimus or cyclosporine (CsA), in an unselected population. In this 12-month, multicenter, open-label study, de novo kidney transplant recipients were randomized to everolimus with tacrolimus (EVR/TAC), everolimus with CsA (EVR/CsA) or MPA with tacrolimus (MPA/TAC), with similar tacrolimus exposure in both groups. Non-inferiority of the primary end point (estimated glomerular filtration rate [eGFR] at month 12), assessed in the per-protocol population of 338 patients, was not shown for EVR/TAC or EVR/CsA versus MPA/TAC. In 123 patients with TAC levels within the protocol-specified range, eGFR outcomes were comparable between groups. The mean increase in eGFR during months 1 to 12 post-transplant, analyzed post hoc, was similar with EVR/TAC or EVR/CsA versus MPA/TAC. The incidence of treatment failure (biopsy proven acute rejection, graft loss or death) was not significant for EVR/TAC but significant for EVR/CsA versus MPA/TAC. Most biopsy-proven acute rejection events in this study were graded mild (BANFF IA). There were no differences in proteinuria between groups. Cytomegalovirus and BK virus infection were significantly more frequent with MPA/TAC. Thus, everolimus with TAC or CsA showed comparable efficacy to MPA/TAC in de novo kidney transplant patients. Non-inferiority of renal function, when pre-specified, was not shown, but the mean increase in eGFR from month 1 to 12 was comparable to MPA/TAC.

Five-year outcomes in kidney transplant patients randomized to everolimus with cyclosporine withdrawal or low-exposure cyclosporine versus standard therapy

HERAKLES was a 1-year randomized, multicenter trial. Patients were randomized at 3 months after kidney transplantation to remain on cyclosporine-based therapy, switch to everolimus without a calcineurin inhibitor (CNI), or switch to everolimus with low-exposure cyclosporine. Overall, 417 of 497 (83.9%) patients from the core study entered a 4-year extension study. The randomized regimen was continued to year 5 in 75.9%, 41.9% and 24.6% of patients in the standard-CNI, CNI-free and low-CNI groups, respectively. Adjusted estimated GFR at year 5 was significantly higher in the CNI-free group versus standard CNI (difference 7.2 mL/min/1.73 m² , P < .001) or low CNI (difference 7.6 mL/min/1.73 m² , P < .001). For patients who continued randomized therapy for 5 years, differences were 14.4 mL/min/1.73 m²  and 10.1 mL/min/1.73 m² , respectively. Biopsy-proven acute rejection occurred during the 4-year extension study in 7.6%, 8.6%, and 9.0% of patients in the standard-CNI, CNI-free and low-CNI groups, respectively (P = .927). In conclusion, conversion to a CNI-free everolimus regimen 3 months after kidney transplantation improved long-term graft function, particularly in patients who continued the CNI-free regimen. Low CNI with everolimus did not improve renal function. Efficacy was comparable between groups but frequent immunosuppression changes should be taken into account.

Onset and progression of diabetes in kidney transplant patients receiving everolimus or cyclosporine therapy: an analysis of two randomized, multicenter trials

Background

Conversion from calcineurin inhibitor (CNI) therapy to a mammalian target of rapamycin (mTOR) inhibitor following kidney transplantation may help to preserve graft function. Data are sparse, however, concerning the impact of conversion on posttransplant diabetes mellitus (PTDM) or the progression of pre-existing diabetes.

Methods

PTDM and other diabetes-related parameters were assessed post hoc in two large open-label multicenter trials. Kidney transplant recipients were randomized (i) at month 4.5 to switch to everolimus or remain on a standard cyclosporine (CsA)-based regimen (ZEUS, n = 300), or (ii) at month 3 to switch to everolimus, remain on standard CNI therapy or convert to everolimus with reduced-exposure CsA (HERAKLES, n = 497).

Results

There were no significant differences in the incidence of PTDM between treatment groups (log rank p = 0.97 [ZEUS], p = 0.90 [HERAKLES]). The mean change in random blood glucose from randomization to month 12 was also similar between treatment groups in both trials for patients with or without PTDM, and with or without pre-existing diabetes. The change in eGFR from randomization to month 12 showed a benefit for everolimus versus comparator groups in all subpopulations, but only reached significance in larger subgroups (no PTDM or no pre-existing diabetes).

Conclusions

Within the restrictions of this post hoc analysis, including non-standardized diagnostic criteria and limited glycemia laboratory parameters, these data do not indicate any difference in the incidence or severity of PTDM with early conversion from a CsA-based regimen to everolimus, or in the progression of pre-existing diabetes.

Trial registration

clinicaltrials.gov, NCT00154310 (registered September 2005) and NCT00514514 (registered August 2007); EudraCT (2006-007021-32 and 2004-004346-40).

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1031-1) contains supplementary material, which is available to authorized users.

Histological findings to five years after early conversion of kidney transplant patients from cyclosporine to everolimus: an analysis from the randomized ZEUS study

Background

Conversion from calcineurin inhibitor (CNI) therapy to everolimus within 6 months after kidney transplantation improves long-term graft function but can increase the risk of mild biopsy-proven acute cellular rejection (BPAR). We performed a post-hoc analysis of histological data from a randomized trial in order to further analyze histologic information obtained from indication and protocol biopsies up to 5 years after transplantation.

Methods

Biopsy samples obtained up to 5 years post-transplant were analyzed from the randomized ZEUS study, in which kidney transplant patients were randomized at month 4.5 to switch to everolimus (n = 154) or remain on cyclosporine (CsA)-based immunosuppression (n = 146). All patients received mycophenolate and steroids.

Results

At least one investigator-initiated biopsy was undertaken in 53 patients in each group between randomization and year 5, with a mean (SD) of 2.6 (1.7) and 2.2 (1.4) biopsies per patient in the everolimus and CsA groups, respectively. In the everolimus and CsA groups, investigator-initiated biopsies showed (i) BPAR in 12.3 and 7.5% (p = 0.182) of patients, respectively, with episodes graded mild in 22/24 and 18/20 cases (ii) CsA toxicity lesions in 4.5 and 10.3% of patients (p = 0.076) (iii) antibody-mediated rejection in 0.6 and 2.7% of patients (p = 0.204), respectively.

Conclusions

This analysis of histological findings in the ZEUS study to 5 years after kidney transplantation shows no increase in antibody-mediated rejection under everolimus-based therapy with a lower rate of CNI-related toxicity compared to a conventional CsA-based regimen, and confirms the preponderance of mild BPAR seen in the main study after the early switch to CsA-free everolimus therapy.

Trial registration

ClinicalTrials.gov NCT00154310. Date of registration: September 12, 2005.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0950-1) contains supplementary material, which is available to authorized users.

Everolimus with cyclosporine withdrawal or low-exposure cyclosporine in kidney transplantation from Month 3: a multicentre, randomized trial

Background.

Randomized trials have shown that early adoption of everolimus-based immunosuppressive regimens without a calcineurin inhibitor (CNI) improves long-term kidney graft function, but the optimal strategy for CNI minimization remains uncertain.

Methods.

In a prospective, randomized, multicentre, 12-month trial, 499 de novo kidney transplant patients were randomized at Month 3 to (i) remain on standard CNI (cyclosporine) therapy with mycophenolic acid, (ii) convert to everolimus with mycophenolic acid or (iii) start everolimus with reduced CNI and no mycophenolic acid (clinical trials registry: ClinicalTrials.gov-NCT00514514).

Results.

The primary endpoint, change in estimated glomerular filtration rate (eGFR) (Nankivell) from randomization to Month 12, was significantly greater in the CNI-free arm versus standard CNI therapy: mean difference 5.6 mL/min/1.73 m 2 [95% confidence interval (CI) 2.8-8.3 mL/min/1.73 m 2 , P < 0.001]. The improvement in eGFR in the CNI-free arm was also higher than in the low-CNI group (mean difference 5.5 mL/min/1.73 m 2 , 95% CI 2.8-8.2 mL/min/1.73 m 2 , P < 0.001), while results were similar in the low-CNI and standard CNI arms. The post-randomization incidence of biopsy-proven acute rejection was 11.7%, 8.1% and 7.9% in the CNI-free, low-CNI and standard CNI groups, respectively (CNI-free versus standard CNI, P = 0.27; low-CNI versus standard CNI, P = 1.00). Adverse events led to study drug discontinuation in 28.7%, 15.5% and 15.2% of CNI-free, low-CNI and standard CNI patients, respectively.

Conclusions.

Everolimus initiation with CNI withdrawal at Month 3 after kidney transplantation achieves a significant improvement in renal function at 12 months, with a similar rate of acute rejection.

CTGF Is Expressed During Cystic Remodeling in the PKD/Mhm (cy/+) Rat Model for Autosomal-Dominant Polycystic Kidney Disease (ADPKD)

Connective tissue growth factor (CTGF, also named CCN2) plays an important role in the development of tubulointerstitial fibrosis, which most critically determines the progression to end-stage renal failure in autosomal-dominant polycystic kidney disease (ADPKD), the most common genetically caused renal disease. We determined CTGF expression in a well-characterized animal model of human ADPKD, the PKD/Mhm (cy/+) rat. Kidneys of 12 weeks old (cy/+) as well as (+/+) non-affected rats were analyzed for CTGF RNA and protein expression by RT-PCR, Northern and Western blot analyses, in situ hybridization, and IHC. Besides the established expression of CTGF in glomerular cells in kidneys of wild-type (+/+) animals, in (cy/+) rats, CTGF mRNA and protein were robustly expressed in interstitial, stellate-shaped cells, located in a scattered pattern underlying the cystic epithelium and in focal areas of advanced tubulointerstitial remodeling. Renal CTGF mRNA and protein expression levels were significantly higher in (cy/+) rats compared with their (+/+) littermates. Detection of CTGF expression in cells adjacent to cystic epithelium and in areas of marked fibrosis suggests a role in the local response to cyst development and indicates that CTGF may be a relevant factor contributing to tubulointerstitial fibrosis in polycystic kidney disease.

Influence of the recipient body mass index on the outcomes after kidney transplantation

PURPOSE

The relationship between the body mass index (BMI) of kidney transplant recipients and outcomes after kidney transplantation (KT) is not fully understood and remains controversial. We studied the influence of BMI on clinically relevant outcomes in kidney transplant recipients.

METHODS

In this retrospective single-centre study, all patients who underwent kidney transplantation at our institution between January 2007 and December 2012 were included. Demographic data and BMI were correlated with the clinical course of the disease, rejection rates, delayed graft function rates, and graft and patient survival.

RESULTS

During the study period, 384 single KTs (130 women and 254 men) were performed. Seventeen percent of the transplants were transplanted within the Eurotransplant Senior Programme (ESP). Most of the transplants were performed using organs that were obtained from donors after brain death (DBD), and living donor kidney transplants were performed in 22.4% of all transplants. The median BMI of the recipients was 25.9 kg/m². Additionally, 13.5% of the recipients had a BMI of 30-34.9 kg/m² and 3.9% had a BMI >35 kg/m². A BMI >30 kg/m² was significantly associated with primary non-function of the kidney (p = 0.047), delayed graft function (p = 0.008), and a higher rate of loss of graft function (p = 0.015). The glomerular filtration rate 12 months after KT was significantly lower in recipients with a BMI >30 kg/m². Multivariate analysis revealed that recipient BMI, among other factors, was an independent risk factor for delayed graft function and graft survival. Patients with a BMI >30 kg/m² had an almost four times higher risk for surgical site infection than did recipients with a lower BMI.

CONCLUSIONS

Increased BMI at kidney transplantation is a predictor of adverse outcomes, including delayed graft function. These findings demonstrate the importance of the careful selection of patients and pre-transplant weight reduction, although the role of weight reduction for improving graft function is not clear.

Response to Rituximab Induction Is a Predictive Marker in B-Cell Post-Transplant Lymphoproliferative Disorder and Allows Successful Stratification Into Rituximab or R-CHOP Consolidation in an International, Prospective, Multicenter Phase II Trial

Purpose The Sequential Treatment of CD20-Positive Posttransplant Lymphoproliferative Disorder (PTLD-1) trial ( ClinicalTrials.gov identifier, NCT01458548) established sequential treatment with four cycles of rituximab followed by four cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy as a standard in the management of post-transplant lymphoproliferative disorder (PTLD) and identified response to rituximab induction as a prognostic factor for overall survival. We hypothesized that rituximab consolidation might be sufficient treatment for patients with a complete response after rituximab induction. Patients and Methods In this prospective, international, multicenter phase II trial, 152 treatment-naive adult solid organ transplant recipients, with CD20⁺ PTLD unresponsive to immunosuppression reduction, were treated with four weekly doses of rituximab induction. After restaging, complete responders continued with four courses of rituximab consolidation every 21 days; all others received four courses of rituximab plus CHOP chemotherapy every 21 days. The primary end point was treatment efficacy measured as the response rate in patients who completed therapy and the response duration in those who completed therapy and responded. Secondary end points were frequency of infections, treatment-related mortality, and overall survival in the intention-to-treat population. Results One hundred eleven of 126 patients had a complete or partial response (88%; 95% CI, 81% to 93%), of whom 88 had a complete response (70%; 95% CI, 61% to 77%). Median response duration was not reached. The 3-year estimate was 82% (95% CI, 74% to 90%). Median overall survival was 6.6 years (95% CI, 5.5 to 7.6 years). The frequency of grade 3 or 4 infections and of treatment-related mortality was 34% (95% CI, 27% to 42%) and 8% (95% CI, 5% to 14%), respectively. Response to rituximab induction remained a prognostic factor for overall survival despite treatment stratification. Conclusion In B-cell PTLD, treatment stratification into rituximab or rituximab plus CHOP consolidation on the basis of response to rituximab induction is feasible, safe, and effective.

Design and rationale of the ATHENA study--A 12-month, multicentre, prospective study evaluating the outcomes of a de novo everolimus-based regimen in combination with reduced cyclosporine or tacrolimus versus a standard regimen in kidney transplant patients: study protocol for a randomised controlled trial

Background

Immunosuppression with calcineurin inhibitors remains the mainstay of treatment after kidney transplantation; however, long-term use of these drugs may be associated with nephrotoxicity. In this regard, the current approach is to optimise available immunosuppressive regimens to reduce the calcineurin inhibitor dose while protecting renal function without affecting the efficacy. The ATHENA study is designed to evaluate renal function in two regimens: an everolimus and reduced calcineurin inhibitor-based regimen versus a standard treatment protocol with mycophenolic acid and tacrolimus in de novo kidney transplant recipients.

Method/Design

ATHENA is a 12-month, multicentre, open-label, prospective, randomised, parallel-group study in de novo kidney transplant recipients (aged 18 years or older) receiving renal allografts from deceased or living donors. Eligible patients are randomised (1:1:1) prior to transplantation to one of the following three treatment arms: everolimus (starting dose 1.5 mg/day; C0 3–8 ng/mL) with cyclosporine or everolimus (starting dose 3 mg/day; C0 3–8 ng/mL) with tacrolimus or mycophenolic acid (enteric-coated mycophenolate sodium at 1.44 g/day or mycophenolate mofetil at 2 g/day) with tacrolimus; in combination with corticosteroids. All patients receive induction therapy with basiliximab. The primary objective is to demonstrate non-inferiority of renal function (eGFR by the Nankivell formula) in one of the everolimus arms compared with the standard group at month 12 post transplantation. The key secondary objective is to assess the incidence of treatment failure, defined as biopsy-proven acute rejection, graft loss, or death, among the treatment groups. Other objectives include assessment of the individual components of treatment failure, incidence and severity of viral infections, incidence and duration of delayed graft function, incidence of indication biopsies, slow graft function and wound healing complications, and overall safety and tolerability. Exploratory objectives include evaluation of left ventricular hypertrophy assessed by the left ventricular mass index, evolution of human leukocyte antigen and non-human leukocyte antigen antibodies, and a cytomegalovirus substudy.

Discussion

As one of the largest European multicentre kidney transplant studies, ATHENA will determine whether a de novo everolimus-based regimen can preserve renal function versus the standard of care. This study further assesses a number of clinical issues which impact long-term outcomes post transplantation; hence, its results will have a major clinical impact.

Trial registration

Clinicaltrials.gov: NCT01843348, date of registration – 18 April 2013; EUDRACT number: 2011-005238-21, date of registration – 20 March 2012

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1220-9) contains supplementary material, which is available to authorized users.

Activation of the peroxisome proliferator-activated receptor γ counteracts sepsis-induced T cell cytotoxicity toward alloantigenic target cells

Sepsis still emerges as a major cause of patient death in intensive care units. Therefore, new therapeutic approaches are mandatory. Because during sepsis progression cytotoxic T lymphocytes (CTLs) can be activated in an autoimmune fashion contributing to multiorgan damage, it remains unclear whether CTLs are activated toward alloantigenic cells. This is important for patients receiving an immunosuppressive therapy to permit organ transplantation and, thus, known to be at high risk for developing sepsis. Therefore, we analyzed whether sepsis activates CTL toward alloantigenic target cells and whether this can be inhibited by PPARγ activation, known to block T helper cell responses. To mimic septic conditions, CTLs were isolated from cecal ligation and puncture-operated mice. CTL cytotoxicity was analyzed following a direct alloantigenic activation regime or following classical ex vivo splenocyte-driven activation in a cytotoxicity assay. With this readout, we found that CTL derived from septic mice enhanced cytotoxicity toward alloantigenic target cells, which was lowered by in vivo and ex vivo PPARγ activation. With CTL derived from T cell-specific PPARγ knockout mice, PPARγ activation was ineffective, pointing to a PPARγ-dependent mechanism. In vivo and ex vivo PPARγ activation reduced Fas and granzyme B expression in activated CTL.

KEY MESSAGE

In the sepsis CLP mouse model, CTLs are activated toward alloantigenic target cells. Sepsis-mediated alloantigenic CTL activation is blocked in vivo by PPARγ activation. PPARγ deletion or antagonization restored rosiglitazone-dependent inhibition of CTL cytotoxicity. PPARγ inhibits the expression of Fas and granzyme B in CTLs.

Efficacy and safety of conversion from cyclosporine to everolimus in living-donor kidney transplant recipients: an analysis from the ZEUS study

Conversion of living-donor kidney transplant patients from calcineurin inhibitor therapy to an mTOR inhibitor is poorly documented. In the prospective, multicentre ZEUS study, 300 kidney transplant recipients without prior rejection (Banff grade >1) and serum creatinine ≤265 μmol/l were randomized to continue cyclosporine or convert to everolimus at 4.5 months post-transplant. In a post hoc analysis of 80 living-donor recipients, adjusted estimated GFR (Nankivell) at month 12 (the primary endpoint) was 74.3 (95% CI [70.7, 77.9]) ml/min/1.73 m(2) with everolimus versus 63.8 (95% CI [60.0, 67.7]) ml/min/1.73 m(2) ) with cyclosporine, a difference of 10.5 ml/min/1.73 m(2) in favour of everolimus (P < 0.001). From randomization to month 12, adjusted estimated GFR increased by a mean of 9.8 (95% CI [6.2, 13.4]) ml/min/1.73 m(2) with everolimus versus -0.7 (95% CI [-4.6, 3.1]) ml/min/1.73 m(2) ) (P < 0.001) with cyclosporine. There were six biopsy-proven acute rejection episodes in everolimus-treated patients (five Banff grade I) and one episode in cyclosporine-treated patients (Banff grade 1). Overall safety profile was similar between groups. Discontinuation due to adverse events occurred in three everolimus patients (7.1%) and five cyclosporine patients (13.2%) between randomization and month 12. Initiation of everolimus with early elimination of calcineurin therapy is associated with a significant renal benefit at 12 months post-transplant that is observed in both living and deceased-donor recipients. (clinicaltrials.gov NCT00154310).

Direct acute tubular damage contributes to Shigatoxin-mediated kidney failure

The pathogenesis and therapy of Shigatoxin 2 (Stx2)-mediated kidney failure remain controversial. Our aim was to test whether, during an infection with Stx2-producing E. coli (STEC), Stx2 exerts direct effects on renal tubular epithelium and thereby possibly contributes to acute renal failure. Mice represent a suitable model because they, like humans, express the Stx2-receptor Gb3 in the tubular epithelium but, in contrast to humans, not in glomerular endothelia, and are thus free of glomerular thrombotic microangiopathy (TMA). In wild-type mice, Stx2 caused acute tubular dysfunction with consequent electrolyte disturbance, which was most likely the cause of death. Tubule-specific depletion of Gb3 protected the mice from acute renal failure. In vitro, Stx2 induced secretion of proinflammatory cytokines and apoptosis in human tubular epithelial cells, thus implicating a direct effect of Stx2 on the tubular epithelium. To correlate these results to human disease, kidney biopsies and outcome were analysed in patients with Stx2-associated kidney failure (n = 11, aged 22–44 years). The majority of kidney biopsies showed different stages of an ongoing TMA; however, no glomerular complement activation could be demonstrated. All biopsies, including those without TMA, showed severe acute tubular damage. Due to these findings, patients were treated with supportive therapy without complement-inhibiting antibodies (eculizumab) or immunoadsorption. Despite the severity of the initial disease [creatinine 6.34 (1.31–17.60) mg/dl, lactate dehydrogenase 1944 (753–2792) U/l, platelets 33 (19–124)/nl and haemoglobin 6.2 (5.2–7.8) g/dl; median (range)], all patients were discharged after 33 (range 19–43) days with no neurological symptoms and no dialysis requirement [creatinine 1.39 (range 0.84–2.86) mg/dl]. The creatinine decreased further to 0.90 (range 0.66–1.27) mg/dl after 24 months. Based on these data, one may surmise that acute tubular damage represents a separate pathophysiological mechanism, importantly contributing to Stx2-mediated acute kidney failure. Specifically in young adults, an excellent outcome can be achieved by supportive therapy only. © 2014 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Transcatheter aortic valve implantation improves outcome compared to open-heart surgery in kidney transplant recipients requiring aortic valve replacement

BACKGROUND

Cardiovascular disease is the most frequent cause of mortality for kidney transplant recipients. Open heart surgery has particularly high mortality and morbidity. As an alternative to traditional aortic valve replacement (AVR) for patients with high-grade aortic stenosis, transcatheter aortic valve implantation (TAVI) was developed as an innovative therapy for patients considered at high surgical risk.

METHODS

We considered all kidney transplant recipients as high-risk patients, which are candidates for TAVI. In 2010 and 2011, eight kidney transplant recipients with severe aortic stenosis underwent TAVI (6 transfemoral; 2 transapical; group I). The outcome of these patients was compared retrospectively to 18 kidney transplant recipients with aortic stenosis, who underwent conventional AVR (group II).

RESULTS

Both groups had similar baseline characteristics, including estimated perioperative risk (EuroSCORE group I vs. group II: 9.5±5.9 vs. 10.4±10.5; p=0.829). All TAVI procedures were performed successfully with excellent functional results. In the TAVI group (group I), all patients were alive at the 12-month follow-up with one cardiovascular event (stroke). In contrast, the surgical group experienced a 30-day-mortality of 11.1% (n=2) and a 1-year-mortality of 16.7% (n=3).

CONCLUSIONS

Based on our center's experience, TAVI appears to be an effective and safe alternative to conventional surgery for AVR in patients with prior renal transplantation. Renal transplantation is not currently identified as a risk factor in our traditional scoring system, and may need to be considered independently when weighing alternatives for AVR.

Treatment of active lupus nephritis with the novel immunosuppressant 15-deoxyspergualin: an open-label dose escalation study

INTRODUCTION

As the immunosuppressive potency of 15-deoxyspergualin (DSG) has been shown in the therapy of renal transplant rejection and Wegener's granulomatosis, the intention of this study was to evaluate the safety of DSG in the therapy of lupus nephritis (LN).

METHODS

Patients with histologically proven active LN after prior treatment with at least one immunosuppressant were treated with 0.5 mg/kg normal body weight/day DSG, injected subcutaneously for 14 days, followed by a break of one week. These cycles were repeated to a maximum of nine times. Doses of oral corticosteroids were gradually reduced to 7.5 mg/day or lower by cycle 4. Response was measured according to a predefined decision pattern. The dose of DSG was adjusted depending on the efficacy and side effects.

RESULTS

A total of 21 patients were included in this phase-I/II study. After the first DSG injection, one patient was excluded from the study due to renal failure. Five patients dropped out due to adverse events or serious adverse events including fever, leukopenia, oral candidiasis, herpes zoster or pneumonia. Eleven out of 20 patients achieved partial (4) or complete responses (7), 8 were judged as treatment failures and 1 patient was not assessable. Twelve patients completed all nine cycles; in those patients, proteinuria decreased from 5.88 g/day to 3.37 g/day (P = 0.028), Selena-SLEDAI (Safety of Estrogens in Lupus Erythematosus-National Assessment-systemic lupus erythematosus disease activity index) decreased from 17.6 to 11.7. In 13 out of 20 patients, proteinuria decreased by at least 50%; in 7 patients to less than 1 g/day.

CONCLUSIONS

Although the number of patients was small, we could demonstrate that DSG provides a tolerably safe treatment for LN. The improvement in proteinuria encourages larger controlled trials.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00709722.

Risk factors for Pneumocystis jiroveci pneumonia (PcP) in renal transplant recipients

BACKGROUND

Pneumocystis jiroveci pneumonia (PcP) is a potentially life-threatening complication in renal transplant recipients with increased reports during the past few years. Individual risk factors for susceptibility to PcP are incompletely understood.

METHODS

We retrospectively analysed 60 cases of confirmed PcP, diagnosed in six German transplant centres between 2004 and 2008, as well as 60 matched controls.

RESULTS

Compared with controls, PcP cases revealed the following significant differences: PcP cases had a poorer renal function (eGFR 31 vs. 42 mL/min in controls), more biopsy-proven rejections (18 vs. 5 patients), more frequent treatment with mycophenolate mofetil (53 vs. 44 patients) and less frequent treatment with interleukin-2 receptor antagonist (20 vs. 32 patients). According to centre policy, in those years, none of the patients or controls had received PcP prophylaxis after transplantation. Of the 60 patients with PcP, 30% developed the disease after the currently recommended duration of prophylactic treatment, 27% died in the course of the disease and 45% required treatment in the ICU.

CONCLUSIONS

Our case-control study reveals a novel risk profile for PcP. Renal transplant recipients with more pronounced renal insufficiency following rejection episodes and treated with intensified immunosuppression are at particular risk for PcP.

The efficacy and safety of 200 days valganciclovir cytomegalovirus prophylaxis in high-risk kidney transplant recipients

Late-onset cytomegalovirus (CMV) disease is a significant problem with a standard 3-month prophylaxis regimen. This multicentre, double-blind, randomized controlled trial compared the efficacy and safety of 200 days' versus 100 days' valganciclovir prophylaxis (900 mg once daily) in 326 high-risk (D+/R-) kidney allograft recipients. Significantly fewer patients in the 200-day group versus the 100-day group developed confirmed CMV disease up to month 12 posttransplant (16.1% vs. 36.8%; p < 0.0001). Confirmed CMV viremia was also significantly lower in the 200-day group (37.4% vs. 50.9%; p = 0.015 at month 12). There was no significant difference in the rate of biopsy-proven acute rejection between the groups (11% vs. 17%, respectively, p = 0.114). Adverse events occurred at similar rates between the groups and the majority were rated mild-to-moderate in intensity and not related to study medication. In conclusion, this study demonstrates that extending valganciclovir prophylaxis (900 mg once daily) to 200 days significantly reduces the incidence of CMV disease and viremia through to 12 months compared with 100 days' prophylaxis, without significant additional safety concerns associated with longer treatment. The number needed to treat to avoid one additional patient with CMV disease up to 12 months posttransplant is approximately 5.

ADAM10 is expressed in human podocytes and found in urinary vesicles of patients with glomerular kidney diseases

Background

The importance of the Notch signaling in the development of glomerular diseases has been recently described. Therefore we analyzed in podocytes the expression and activity of ADAM10, one important component of the Notch signaling complex.

Methods

By Western blot, immunofluorescence and immunohistochemistry analysis we characterized the expression of ADAM10 in human podocytes, human urine and human renal tissue.

Results

We present evidence, that differentiated human podocytes possessed increased amounts of mature ADAM10 and released elevated levels of L1 adhesion molecule, one well known substrate of ADAM10. By using specific siRNA and metalloproteinase inhibitors we demonstrate that ADAM10 is involved in the cleavage of L1 in human podocytes. Injury of podocytes enhanced the ADAM10 mediated cleavage of L1. In addition, we detected ADAM10 in urinary podocytes from patients with kidney diseases and in tissue sections of normal human kidney. Finally, we found elevated levels of ADAM10 in urinary vesicles of patients with glomerular kidney diseases.

Conclusions

The activity of ADAM10 in human podocytes may play an important role in the development of glomerular kidney diseases.

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.

CXCL16 is expressed in podocytes and acts as a scavenger receptor for oxidized low-density lipoprotein

Podocytes are a crucial cell type in the kidney and play an important role in the pathology of glomerular kidney diseases like membranous nephropathy (MN). The identification of new factors involved in the progression of glomerular kidney diseases is of great importance to the development of new strategies for the treatment of renal injury. Here we demonstrate that CXCL16 and ADAM10 are constitutively expressed in human podocytes in normal renal tissue. Proinflammatory cytokines like interferon-gamma and tumor necrosis factor-alpha induced the expression of cellular CXCL16 and the release of its soluble form from human podocytes. Using different metalloproteinase inhibitors, we provide evidence that ADAM10 is involved in the interferon-gamma- and tumor necrosis factor-alpha-induced shedding of CXCL16 from human podocytes. In addition, ADAM10 knockdown by siRNA significantly increased both CXCL16 levels and, surprisingly, its ADAM17-mediated release. Notably, targeting of CXCL16 in human podocytes both decreased the chemotaxis of CXCR6-expressing T cells and strongly reduced oxidized low-density lipoprotein uptake in human podocytes. Importantly, in kidney biopsies of patients with MN, increased glomerular CXCL16 expression was accompanied by high levels of oxidized low-density lipoprotein and decreased expression of ADAM10. In addition, we found increased glomerular ADAM17 expression in patients diagnosed with MN. In summary, we presume important roles for CXCL16, ADAM10, and ADAM17 in the development of MN, suggesting these proteins as new therapeutic targets in this glomerular kidney disease.

Cholesterol-crystal embolism presenting with delayed graft function and impaired long-term function in renal transplant recipients: two case reports

Introduction

Impaired renal function and/or pre-existing atherosclerosis in the deceased donor increase the risk of delayed graft function and impaired long-term renal function in kidney transplant recipients.

Case presentation

We report delayed graft function occurring simultaneously in two kidney transplant recipients, aged 57-years-old and 39-years-old, who received renal allografts from the same deceased donor. The 62-year-old donor died of cardiac arrest during an asthmatic state. Renal-allograft biopsies performed in both kidney recipients because of delayed graft function revealed cholesterol-crystal embolism. An empiric statin therapy in addition to low-dose acetylsalicylic acid was initiated. After 10 and 6 hemodialysis sessions every 48 hours, respectively, both renal allografts started to function. Glomerular filtration rates at discharge were 26 ml/min/1.73m² and 23.9 ml/min/1.73m², and remained stable in follow-up examinations. Possible donor and surgical procedure-dependent causes for cholesterol-crystal embolism are discussed.

Conclusion

Cholesterol-crystal embolism should be considered as a cause for delayed graft function and long-term impaired renal allograft function, especially in the older donor population.

Reactivation of hepatitis B two years after rituximab therapy in a renal transplant patient with recurrent focal segmental glomerulosclerosis: a note of caution

We report on the reactivation of hepatitis B in a renal transplant patient who had been treated with rituximab for recurrent focal segmental glomerulosclerosis two and a half yr previously. He lost his anti-hepatitis B surface antigens and anti-hepatitis B core antigen antibodies and developed hepatitis B virus (HBV)-DNA positive hepatitis. Hepatitis C, which had been successfully treated by alpha interferon 10 yr before, remained quiescent. We suggest regular controls of HBV-DNA, anti-HBV antibodies and transaminases for prolonged periods in patients with status post-hepatitis B treated with rituximab. Prophylactic therapy with lamivudine and/or hepatitis B hyperimmune globulin may be considered in patients with a decrease in anti-HBV antibodies.

Synergistic induction of osteopontin by aldosterone and inflammatory cytokines in mesangial cells

Hypertensive nephrosclerosis is characterized by activation of the renin-angiotensin-aldosterone system in combination with an inflammatory response characterized by an infiltration of T-cells and mononuclear cells, which release proinflammatory cytokines like IL-1beta/TNFalpha. In various models of experimental hypertensive disease the chemokine osteopontin (OPN) enhances further leukocyte infiltration. Therefore, we investigated the induction of OPN expression in renal mesangial cells (MCs) by aldosterone and the inflammatory cytokines IL-1beta/TNFalpha. Incubation with aldosterone resulted in a time- and concentration-dependent increase in OPN mRNA and protein. OPN mRNA expression followed a biphasic time course with an early increase between 4 and 8 h and the second phase starting at 14 h. The early phase was independent of protein synthesis, indicating a direct effect of aldosterone. Aldosterone-mediated induction of OPN was prevented by spironolactone, indicative of a receptor-mediated aldosterone effect. The mineralocorticoid receptor (MR) was identified in MCs by RT-PCR and immunoprecipitation, and shown to interact with a putative aldosterone-response element of the OPN promoter. The proinflammatory cytokines IL-1beta and TNFalpha only marginally affected OPN expression in MCs. However, coincubation of aldosterone and the cytokines synergistically increased OPN mRNA and protein levels. Since the synergistic effect on OPN mRNA was inhibited by diphenyleneiodonium, we assume an involvement of reactive oxygen species (ROS). We conclude that the chemokine OPN is a target gene of aldosterone in renal MCs, which is activated via the MR, and that proinflammatory cytokines enhance aldosterone-dependent OPN expression. In vivo, this may result in further leukocyte infiltration aggravating hypertensive nephrosclerosis.

A randomized, multicenter study of steroid avoidance, early steroid withdrawal or standard steroid therapy in kidney transplant recipients

In a randomized, open-label, multicenter study, de novo renal transplant patients received no steroids (n = 112), steroids to day 7 (n = 115), or standard steroids (n = 109) with cyclosporine microemulsion (CsA-ME), enteric-coated mycophenolate sodium (EC-MPS) and basiliximab. The primary objective, to demonstrate noninferiority of 12-month GFR in the steroid-free or steroid-withdrawal groups versus standard steroids, was not met in the intent-to-treat population. However, investigational groups were not inferior to standard steroids in the observed-case analysis. Median 12-month GFR was not significantly different in the steroid-free or steroid-withdrawal groups (58.6 mL/min/1.73 m(2) and 59.1 mL/min/1.73 m(2)) versus standard steroids (60.8 mL/min/1.73 m(2)). The 12-month incidence of biopsy-proven acute rejection (BPAR), graft loss or death was 36.0% in the steroid-free group (p = 0.007 vs. standard steroids), 29.6% with steroid withdrawal (N.S.) and 19.3% with standard steroids. BPAR was significantly less frequent with standard steroids than either of the other two regimens. Reduced de novo use of antidiabetic and lipid-lowering medication, triglycerides and weight gain were observed in one or both steroid-minimization group versus standard steroids. For standard-risk renal transplant patients receiving CsA-ME, EC-MPS and basiliximab, steroid withdrawal by the end of week 1 achieves similar 1-year renal function to a standard-steroids regimen, and may be more desirable than complete steroid avoidance.

A randomized, multicenter study of steroid avoidance, early steroid withdrawal or standard steroid therapy in kidney transplant recipients

In a randomized, open-label, multicenter study, de novo renal transplant patients received no steroids (n = 112), steroids to day 7 (n = 115), or standard steroids (n = 109) with cyclosporine microemulsion (CsA-ME), enteric-coated mycophenolate sodium (EC-MPS) and basiliximab. The primary objective, to demonstrate noninferiority of 12-month GFR in the steroid-free or steroid-withdrawal groups versus standard steroids, was not met in the intent-to-treat population. However, investigational groups were not inferior to standard steroids in the observed-case analysis. Median 12-month GFR was not significantly different in the steroid-free or steroid-withdrawal groups (58.6 mL/min/1.73 m(2) and 59.1 mL/min/1.73 m(2)) versus standard steroids (60.8 mL/min/1.73 m(2)). The 12-month incidence of biopsy-proven acute rejection (BPAR), graft loss or death was 36.0% in the steroid-free group (p = 0.007 vs. standard steroids), 29.6% with steroid withdrawal (N.S.) and 19.3% with standard steroids. BPAR was significantly less frequent with standard steroids than either of the other two regimens. Reduced de novo use of antidiabetic and lipid-lowering medication, triglycerides and weight gain were observed in one or both steroid-minimization group versus standard steroids. For standard-risk renal transplant patients receiving CsA-ME, EC-MPS and basiliximab, steroid withdrawal by the end of week 1 achieves similar 1-year renal function to a standard-steroids regimen, and may be more desirable than complete steroid avoidance.

Renal transplantation in the elderly: surgical complications and outcome with special emphasis on the Eurotransplant Senior Programme

BACKGROUND

The purpose of this retrospective study was to evaluate the results of the Eurotransplant Senior Programme (ESP) within our centre compared to elderly recipients >or=60 years from the regular Eurotransplant Kidney Allocation System (ETKAS), specifically focusing on surgical aspects.

METHODS

Data from 73 ESP patients (average donor/recipient age: 71.1/67.1) were compared with those from 51 patients (49.7/63.6) treated within the framework of the ETKAS program between the years 1999 and 2006. The mean follow-up was 39.5 months.

RESULTS

Cold ischaemic time (ESP versus ETKAS: 10.3 versus 15.0 h), duration of renal replacement therapy (42.2 versus 76.8 months), donor glomerular filtration rate (81.7 versus 109.9 ml/min/1.73 m(2)) and HLA mismatches (4.1 versus 2.4) were significantly different between the two groups (all P < 0.001). Primary graft function was seen in 74% ESP versus 69% of ETKAS patients (P > 0.05). The rate of surgical complications in the ESP versus ETKAS group was 47% versus 28% (P = 0.031) and the revision rate, 33% versus 24% (P = 0.259). Three-year patient and censored graft survival was 84% versus 92% and 85% versus 88% in the ESP and ETKAS group, respectively (all P > 0.05). Ninety-five percent of all deceased patients died with a functioning graft.

CONCLUSIONS

The donor and recipient pool has been markedly expanded through ESP with similar patient and graft survival compared to elderly recipients grafted according to ETKAS criteria. However, patients and their physicians should be aware of the high surgical complication rate in elderly recipients, particularly when receiving elderly donor kidneys. This might seriously influence postoperative patient management but ultimately does not compromise the transplant outcome.

IL-18 is expressed in the intercalated cell of human kidney

We determined the cellular location of interleukin-18 (IL-18) and caspase-1 and the purinergic receptor P2X7, two proteins necessary for its activation and secretion. The mRNA and protein of IL-18 were detectable in normal human kidney by means of polymerase chain reaction (PCR), in situ hybridization, and Western blot. Immunohistochemistry located IL-18 to nephron segments containing calbinbin-D28k or aquaporin-2 that suggest location in the distal convoluted and the connecting tubule and to parts of the collecting duct. IL-18 was not detected in the thick ascending limb of Henle. Confocal microscopy showed that IL-18 was expressed in cells negative for calbindin-D28k and for aquaporin-2 but positive for the vacuolar H(+)-ATPase. This demonstrates that the intercalated cells produce IL-18. These segments were also positive for caspase-1 and P2X7 that are essential for IL-18 secretion. Our results show that IL-18 is constitutively expressed by intercalated cells of the late distal convoluted tubule, the connecting tubule, and the collecting duct of the healthy human kidney. Since IL-18 is an early component of the inflammatory cytokine cascade, its location suggests that renal intercalated cells may contribute to immediate immune response of the kidney.

Abrogation of nephrotic proteinuria by rituximab treatment in a renal transplant patient with relapsed focal segmental glomerulosclerosis

Relapse of focal segmental glomerulosclerosis (FSGS) after renal transplantation is 20-40%. Recurrence after a first relapse is 80%. The only current treatment is plasmapheresis and/or cyclophosphamide. We report successful treatment of a second relapse in a 48-year-old patient. At age 33, FSGS was diagnosed. The patient began hemodialysis 1 year later. In her first renal transplant, she developed recurrent FSGS and reached terminal transplant failure 3 years later. Eight years later, a second transplant was performed. Immunosuppressive regimen: steroids, mycophenolate mofetil (MMF), tacrolimus (TAC), and rabbit anti-thymocyte globulin. Proteinuria of 2-6 g/day was detected and a biopsy showed recurrent FSGS. Plasmapheresis was started without success. Another biopsy still showed FSGS. The patient received two doses of rituximab (375 mg/m2 each) i.v. Three weeks later, proteinuria was 350 mg/day (serum-creatinine 1.6 mg/dl). Twelve months later, proteinuria was at 90 mg/day. Rituximab might be an option for recurrent FSGS after renal transplantation.