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Background and objectives Forkhead box P3 regulatory T cells control inflammatory responses, but it remains unclear whether they inhibit brain death-initiated inflammation and tissue injury in deceased kidney donors. Design, setting, participants, & measurement To study the actions of regulatory T cells at various stages of the donation and transplantation procedure, forkhead box P3, regulatory and inflammatory cytokine expression, and tissue injury markers were determined in time 0 kidney biopsies from deceased and living donors. Additionally, the interaction between forkhead box P3+ T cells and kidney injury molecule-1 by activated primary tubular epithelial cells was studied. Results After cold storage, the deceased donor kidneys expressed the higher mRNA levels of kidney injury molecule-1 and CD3e. In these samples, the inflammatory cytokines IL-8 and IFN-γ and markers associated with regulation (forkhead box P3, TGF-β, and IL-10) were highly expressed compared with living donor kidneys. Correlations were found between mRNA expression levels of forkhead box P3 and kidney injury molecule-1 and forkhead box P3 and IFN-γ. Immunohistochemical analysis confirmed the presence of forkhead box P3+ T cells in donor kidneys. Renal function (analyzed by serum creatinine levels) at the first week posttransplantation correlated with kidney injury molecule-1 and forkhead box P3 mRNA levels. In vitro studies showed that kidney injury molecule-1 expression by primary tubular epithelial cells was 63% (mean) lower when cocultured with regulatory T cells compared with control T cells. Conclusions These results show that donor forkhead box P3+ T cells infiltrate the deceased donor kidney, where they may control inflammatory and injury responses.

In this Phase 2b study, 331 low-to-moderate risk de novo kidney transplant patients (approximately 60% deceased donors) were randomized to a more intensive (MI) or less intensive (LI) regimen of tofacitinib (CP-690, 550), an oral Janus kinase inhibitor or cyclosporine (CsA). All patients received basiliximab induction, mycophenolic acid and corticosteroids. Primary endpoints were: incidence of biopsy-proven acute rejection (BPAR) with a serum creatinine increase of =0.3 mg/dL and =20% (clinical BPAR) at Month 6 and measured GFR at Month 12. Similar 6-month incidences of clinical BPAR (11%, 7% and 9%) were observed for MI, LI and CsA. Measured GFRs were higher (p < 0.01) at Month 12 for MI and LI versus CsA (65 mL/min, 65 mL/min vs. 54 mL/min). Fewer (p < 0.05) patients in MI or LI developed chronic allograft nephropathy at Month 12 compared with CsA (25%, 24% vs. 48%). Serious infections developed in 45%, 37% and 25% of patients in MI, LI and CsA, respectively. Anemia, neutropenia and posttransplant lymphoproliferative disorder occurred more frequently in MI and LI compared with CsA. Tofacitinib was equivalent to CsA in preventing acute rejection, was associated with improved renal function and less chronic allograft histological injury, but had side-effects at the doses evaluated.

Incentives for organ donation, currently prohibited in most countries, may increase donation and save lives. Discussion of incentives has focused on two areas: (1) whether or not there are ethical principles that justify the current prohibition and (2) whether incentives would do more good than harm. We herein address the second concern and propose for discussion standards and guidelines for an acceptable system of incentives for donation. We believe that if systems based on these guidelines were developed, harms would be no greater than those to today's conventional donors. Ultimately, until there are trials of incentives, the question of benefits and harms cannot be satisfactorily answered.

Immunosuppressive drugs used in organ transplantation are highly effective in preventing acute rejection. However, the clinical use of these drugs is complicated by the fact that they display highly variable pharmacokinetics and pharmacodynamics between individual patients. The influence of genetic variation on the interindividual variability in immunosuppressive drug disposition, efficacy, and toxicity has been explored in recent years. The polymorphically-expressed ATP-binding cassette (ABC) transporter proteins, in particular ABCB1 and ABCC2, have been investigated extensively because they play an important role in the absorption, distribution and elimination of many immunosuppressive drugs in use today. From these studies it can be concluded that polymorphisms in ABCB1 and ABCC2 have no consistent effect on immunosuppressant pharmacokinetics and toxicity although polymorphisms in ABCB1 appear to be related to the risk of developing calcineurin inhibitor-related nephrotoxicity. However, the latter needs to be replicated before an individual's ABCB1 genotype can become a useful marker that is applied in clinical practice. Future studies evaluating the influence of ABC transporter gene polymorphisms should explore the relationship with intracellular rather than systemic drug concentrations further in well-designed clinical studies. Until then, single-nucleotide polymorphisms in ABC transporter genes are not suitable to act as biomarkers for solid organ transplantation. (C) 2011 Elsevier B.V. All rights reserved.

BACKGROUND The common γ-chain (γ(c)) cytokines signal through the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway and play pivotal roles in lymphocyte activation. We investigated the effect of immunosuppressive drugs targeting this pathway, the JAK inhibitor tofacitinib (CP-690,550) and the anti-interleukin (IL)-2R antibody basiliximab, as part of a phase 2 study. METHODS After whole-blood activation with the γ(c) cytokines IL-2, IL-7, and IL-15, STAT5 phosphorylation was determined in T cells of de novo kidney transplantation patients treated with tofacitinib/basiliximab (n=5), calcineurin inhibitor (CNI) (cyclosporine A)/basiliximab (n=4) or CNI (tacrolimus)-based immunosuppression (n=6). The IC(50) for phosphorylated STAT (P-STAT) 5 inhibition by tofacitinib was determined in cytokine-activated CD4(+) and CD8(+) T cells from healthy individuals (n=4). RESULTS IC(50) was 26, 72, and 37 ng/mL for IL-2, IL-7, and IL-15 activation, in CD4(+) T cells, respectively; and 35, 61, and 76 ng/mL for IL-2, IL-7, and IL-15 activation, in CD8(+) T cells, respectively. In kidney transplantation patients, 7 days after starting tofacitinib/basiliximab treatment, cytokine-induced P-STAT5 was inhibited in CD4(+) T cells (92% for IL-2 activation, 60% for IL-7, and 75% for IL-15), which persisted for the 2-month study period. In contrast, CNI/basiliximab treatment did not affect IL-7-activated or IL-15-activated P-STAT5; only IL-2-activated P-STAT5 was reduced by 77% on day 7 and recovered to pretreatment levels within 2 months. CD8(+) T cells showed a comparable profile to CD4(+) T cells. P-STAT5 was not inhibited in CNI-treated control patients. CONCLUSIONS Tofacitinib therapy strongly inhibits γ(c) cytokine-induced JAK/STAT5 activation, whereas basiliximab suppresses IL-2-stimulated activation only. Pharmacodynamic monitoring offers a unique tool to evaluate the biologic effects of immunosuppressive drugs.

Background: End-stage renal disease (ESRD) is associated with T-cell dysregulation, leading to a variable degree of lymphopenia and increased T-cell differentiation. This may cause a relevant reduction in T-cell immunity, yielding a lowered risk for acute rejection (AR) of kidney allografts. Methods: Before kidney transplantation, circulating CD4 and CD8 + T-cell differentiation was established by determining the frequency of naive T cells, central memory and effector memory T cells, and the highly differentiated CD8 + Temra cells. In addition, the frequency of differentiated T cells without expression of the costimulatory molecule CD28 + was measured. Results: In 47 patients of the 185 patients included, a biopsy-proven AR occurred. Compared with healthy controls, T cells of patients with ESRD were significantly more differentiated. Patients with AR showed the least signs of T-cell dysregulation with significantly more T cells, more naive T cells, and less terminal differentiation of memory T cells compared with nonrejecting patients. After multivariate analysis, only the frequency of terminally differentiated CD8 + Temra cells (per percent, 4% decrease of risk [P=0.006]; per tertile, 34% decrease in risk [P=0.002]) and the number of human leukocyte antigen mismatches (per mismatch, 33% [P=0.005]) predicted the risk for AR. Functional analysis showed that CD8 Temra cells have a highly proinflammatory and cytotoxic profile. In vitro T-cell proliferation assays did not reveal a suppressor function of these cells. Conclusions: Advanced ESRD-related T-cell dysregulation that is associated with a relative increase of terminally differentiated CD8 + Temra cells protects against AR after kidney transplantation.

The Declaration of Istanbul is the first document that has been established by the international transplant community that defines and prohibits transplant commercialism and organ trafficking. Its Custodian Group has successfully led various countries to implement legislation against trafficking and commercialism. The question arises, however, whether efforts to prohibit organ trade are realistic and effective. The Declaration differentiates trafficking from commercialism, yet it does not mention how both acts should be approached by policy. Policies that address transplant commercialism work differently from policies that tackle organ trafficking. There is considerable room for improvement in the current prohibitive approach to commercialism and organ trafficking. The Custodian Group and World Health Organization (WHO) should address commercialism by encouraging the expansion of living donation in the same manner as they encourage deceased donation. Furthermore, the Custodian Group and the WHO can improve their strategy to combat organ trafficking by raising awareness for enforcement. To achieve a consistent and effective prohibition of trafficking, legislation and law enforcement must go hand in hand. Ideally, this can best be achieved by close collaboration between the medical field and (international) criminal justice agencies.

Cytokines of the IL-2 receptor family act via activation of the JAK-STAT (janus tyrosine kinase-signal transducer and activator of transcription) signaling pathway. These cytokines are pivotal for the development and function of lymphocyte subsets involved in the immune response after organ transplantation including T. B and natural killer cells. The new small drug molecule and JAK1/3 inhibitor, tofacitinib, is currently being tested in phase II and III clinical trials for rheumatoid arthritis, psoriasis and in organ transplantation. This agent specifically targets the JAK-STAT signaling pathway. Here we discuss phosphospecific flow cytometry as a novel tool to monitor the JAR-STAT signaling pathway in kidney transplant patients and speculate that through the use of this pharmacodynamic tool the efficacy of immunosuppressive drugs can be assessed enabling optimization of the immunosuppressive therapy for individual transplant patients. (C) 2012 Elsevier B.V. All rights reserved.

Summary Imagine a Samaritan living kidney donor, who some time ago has anonymously donated one of his kidneys to a patient on top of the waiting list. He now contacts the transplantation centre once again, to donate part of his liver. The Centre, startled by this idea, refers him to the regular screening procedure for all Samaritan donations. It turns out that his wish is well-informed, voluntarily made and that he is competent to decide. We acknowledge that a donor’s wish should not be followed in all cases, even though this wish is a clear expression of his own free will. However, a refusal must be based on sound moral reasons and it is less clear what reasons these might be. We outline the most common arguments for refusal, assess these arguments in terms of strengths and weaknesses, and show which arguments, if any at all, are most promising. We conclude, firstly, that we should only assess risks (which include motivations), not judge relationships, and secondly, that it is not a transplant centre’s mission to carry out a donor’s life project.

Background The association of CYP3A5, CYP3A4, and ABCB1 single nucleotide polymorphisms (SNPs) with cyclosporine (CsA) pharmacokinetics is controversial. The authors studied the influence of these SNPs on CsA pharmacokinetics as well as on the incidence of biopsy-proven acute rejection (BPAR) and renal function after kidney transplantation. Method One hundred seventy-one patients participating in an international, randomized controlled trial were genotyped for CYP3A5*3, CYP3A4*1B and the ABCB1 1236 C>T, 2677 G>T/A, and 3435 C>T SNPs. The patients were treated with CsA, mycophenolate mofetil, and glucocorticoids. CsA was dosed to reach predose concentrations (C0) or two hours postdose concentrations (C2). Pharmacokinetic parameters were measured on Days 3 and 10 and Months 1, 3, 6, and 12 after transplantation. Renal function was assessed by measuring serum creatinine and calculating the creatinine clearance. The incidence of BPAR and delayed-graft function was recorded. Results CYP3A5, CYP3A4, and ABCB1 genotype were not associated with dose-adjusted CsA C0 or C2. The incidence of BPAR in this cohort was 16% and was comparable between the different ABCB1 genotype groups. No significant difference in the incidence of BPAR was found between CYP3A5 expressers (10%) and nonexpressers (18%) (P = 0.24) nor was there a difference in the incidence of BPAR between CYP3A4*1 homozygotes (5%) versus CYP3A4*1B carriers (18%) (P = 0.13). There were no differences with regard to creatinine clearance between the different CYP3A and ABCB1 genotype groups. Conclusion According to the results, determination of CYP3A and ABCB1 SNPs pretransplantation is not helpful in determining the CsA starting dose and does not aid in predicting the risk of BPAR or worse renal function in an individual patient.

The safety of older live kidney donors, especially the decline in glomerular filtration rate (GFR) after donation, has been debated. In this study we evaluated long-term renal outcome in older live kidney donors. From 1994 to 2006 follow-up data of 539 consecutive live kidney donations were prospectively collected, during yearly visits to the outpatient clinic. Donors were categorized into two groups, based on age: < 60 (n = 422) and >= 60 (n = 117). Elderly had lower GFR predonation (80 vs. 96 mL/min respectively, p < 0.001). During median follow-up of 5.5 years, maximum decline in eGFR was 38% +/- 9% and the percentage maximum decline was not different in both groups. On long-term follow-up, significantly more elderly had an eGFR < 60 mL/min (131 (80%) vs. 94 (31%), p < 0.001). However, renal function was stable and no eGFR of less than 30 mL/min was seen. In multivariate analysis higher body mass index (HR 1.09, 95%CI 1.03-1.14) and more HLA mismatches (HR 1.17, 95%CI 1.03-1.34) were significantly correlated with worse graft survival. Donor age did not influence graft survival. After kidney donation decline in eGFR is similar in younger and older donors. As kidney function does not progressively decline, live kidney donation by elderly is considered safe.

This article reports the case of a 57-year-old woman who was diagnosed with primary aldosteronism after renal transplantation. The authors discuss the challenges of diagnosing this syndrome in patients with chronic kidney disease, the importance of identifying this condition owing to its association with cardiovascular risk and renal function impairment, and available treatment options. Background. A 57-year-old woman was referred to a nephrology clinic because of chronic hypokalemia. She had a history of polycystic kidney disease, resistant hypertension, atrial fibrillation, type 2 diabetes, stroke, and end-stage renal disease, and had received a kidney transplant from a deceased donor at the age of 48 years. At presentation, the patient described symptoms of chronic fatigue and muscle aches, but she did not report pareses. Her medications included four antihypertensive agents, glucose-lowering drugs, immunosuppressants, digoxin, a coumarin derivative, and potassium chloride. Investigations. Full history, physical examination, laboratory testing of blood and urine, including aldosterone-torenin ratio, and a saline infusion test. Diagnosis. Primary aldosteronism. Management. Treatment with spironolactone resulted in prompt control of hypertension and hypokalemia, allowing discontinuation of potassium chloride and reduction in antihypertensive medication.

Introduction: Since 1995, several immunosuppressive drugs have entered the field of organ transplantation: tacrolimus, mycophenolate and the mTOR-inhibitors. Now treating physicians have a choice. Areas covered: The authors review the important studies on immunosuppressive drugs used at present after kidney transplantation, published in the last three decades. This review also discusses the available evidence for selecting one of the calcineurin inhibitors, antiproliferative agents and induction therapy. Interesting new drugs are discussed briefly. Expert opinion: Calcineurin inhibitors (CNIs) are considered, especially in de novo transplantation, to be the most effective maintenance drugs to prevent acute rejection. Combining CNI with mycophenolate or an mTOR-inhibitor has made it possible to reduce CNI dose and diminish nephrotoxicity. Uniform treatment regimes according to guidelines are useful but should leave room for adjustment to the needs of individual patients. Longer follow-up studies are needed to decide on the optimal maintenance treatment.

This study investigated specific gene expression profiles in patients with donor-specific cytotoxic-hyporesponsiveness, reflected by cytotoxic T-lymphocyte precursor frequency (CTLpf). The effect of calcineurin inhibitor (CNI) withdrawal was studied on markers for cytotoxicity (perforin, granzyme B), apoptosis (Fas,FasL), Th1 and Th2 cytokines (IL-2, IL-10), Th1 and Th2 transcription factors (T-bet, GATA 3), Th17 transcription factor and cytokine (RORγt, IL-17), and for immune regulation/activation (CD25, FOXP3). Peripheral blood samples from renal allograft recipients (n = 18) more than two yr after transplantation with stable renal function were analyzed before and four months after CNI withdrawal. Additionally, systolic and diastolic blood pressure, cholesterol, serum creatinine and proteinuria were evaluated, and no significant differences were measured before and after CNI withdrawal. However, CNIs' discontinuation influenced peripheral gene expression profiles. After CNI withdrawal, the mRNA expression of Granzyme B, Perforin, Fas, FasL, T-bet, GATA3 and CD25 were significantly lower than during CNI treatment. After CNI discontinuation, donor-specific CTLpf decreased, while FOXP3 expression discriminated between detectable and non-detectable donor-specific cytolysis reactivity; FOXP3 transcript values were highest in absence of donor-specific cytotoxicity (p < 0.01). Our study shows CNI withdrawal in stable kidney transplant recipients two yr after transplantation is safe. Moreover, discontinuation of CNIs' treatment allows FOXP3+ regulatory T-cells development, resulting in a significant decrease of anti-donor immune reactivity.

Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD) and may present after kidney transplantation, a condition known as posttransplantation EPS. The prevalence and impact of posttransplantation EPS on survival after kidney transplantation is unknown. From January 1, 1996 until July 1, 2007, 1241 PD patients were transplanted. Thirty-eight cases of posttransplantation EPS (3%) were identified from the Dutch multicenter EPS study. In EPS patients the mean pretransplant dialysis duration was longer than in the controls (71.4 ± 37.5 months vs. 34.7 ± 25.5, p < 0.0001). The majority of EPS cases were observed within the first 2 years after transplantation, but some cases appeared many years after transplantation. Two hundred and one (16.2%) patients died after transplantation, of which 17 were EPS patients. After infection (23.9%), cardiovascular disease (21.9%) and malignancy (10.9%), EPS (8.5%) was the fourth known cause of death after transplantation. Kaplan-Meier analysis showed a significant decreased survival for transplanted patients with posttransplantation EPS compared to transplanted patients without EPS. In conclusion, posttransplantation EPS is rare but carries a high mortality. A prolonged clinical vigilance and a high index of suspicion for the diagnosis are warranted, specifically in PD patients with a relatively long cumulative pretransplant duration of PD.

Item does not contain fulltext INTRODUCTION: Malignancy is a well-known complication after renal transplantation. We studied the influence of cancer on patient survival in the Dutch renal transplant population in a nested case-controlled analysis. METHODS: Between March 1966 and May 2008, 15,227 renal transplantations in 12,805 recipients were registered in the Netherlands Organ Transplant Registry database. Total follow-up was 89,651 person years. We performed an analysis of patient and graft survival both from the day of transplantation and the diagnosis of cancer in recipients with invasive cancer. Recipients without invasive cancer, matched for gender, age, and year of transplantation, served as a control group. For the survival analysis after the diagnosis of cancer, the matched control group consisted of patients with a functioning graft at the moment the index patient was diagnosed with cancer. RESULTS: Cancer had been registered in 908 (7.1%) patients, 630 (69%) of them died with functioning kidney, 510 (81%) because of their malignancy (at 8.2 years after transplantation, median). The median patient survival after transplantation was 11.9 vs. 16.8 years in the study and control group, respectively (P

SummaryLiving donor kidney exchange programs offer incompatible donor–recipientpairs the opportunity to be transplanted. To increase the number of thesetransplants, we examined in our actual donor–recipient couples how to reachthe maximum number of matches by using different chain lengths. We per-formed 20 match procedures in which we constructed four different chainlengths: two, up to three, up to four and unlimited. The actual inflow and out-flow of donor–recipient couples for each run were taken into consideration inthis analysis. The total number of matched pairs increased from 148 pairs foronly two-way exchanges to 168 for three-way exchanges. When a chain lengthof 4 was allowed five extra couples could be matched over a period of 5 years.Unlimited chain length did not significantly affect the results. The optimalchain length for living donor kidney exchange programs is 3. Longer chainswith their inherent logistic burden do not lead to significantly more trans-plants. Transplant International ISSN 0934-0874

Background. Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis (PD) with an increasing incidence. There is no clear consensus on the treatment of EPS, but anecdotal reports indicate improvement in EPS patients treated with tamoxifen. At present, there is no evidence for the effect of tamoxifen treatment in EPS patients. This study investigates the effect of treatment with tamoxifen on survival in EPS patients. Methods. This study is a retrospective analysis of survival in EPS patients as part of the Dutch multicentre EPS study in the period January 1996 to July 2007. Sixty-three patients with severe EPS were followed up until August 2008. Demographic, patient and PD-related variables of EPS patients were investigated. Patients treated with tamoxifen were compared to patients not treated with tamoxifen. Survival was analysed with multivariate Cox regression analysis. Results. Twenty-four patients were treated with tamoxifen, and 39 were not treated with tamoxifen. The clinical and demographic characteristics were similar for the tamoxifen-treated and non-treated groups. The mortality rate was significantly lower in tamoxifen-treated patients compared to EPS patients not treated with tamoxifen (45.8% vs 74.4%, P = 0.03). Survival in tamoxifen-treated patients, adjusted for calendar time, age, use of corticosteroids, presence of functioning transplantation, use of parental nutrition and centre influences was longer in comparison to not-treated patients (HR 0.39, P = 0.056). Conclusions. Tamoxifen treatment in EPS patients is associated with lower mortality and shows a trend to an increased multivariate-adjusted survival. This supports additional use of tamoxifen to treat patients with severe EPS.

P>Laparoscopic donor nephrectomy (LDN) is less traumatic and painful than the open approach, with shorter convalescence time. Hand-assisted retroperitoneoscopic (HARP) donor nephrectomy may have benefits, particularly in left-sided nephrectomy, including shorter operation and warm-ischemia time (WIT) and improved safety. We evaluated outcomes of HARP alongside LDN. From July 2006 to May 2008, 20 left-sided HARP procedures and 40 left-sided LDNs were performed. Intra and postoperative data were prospectively collected and analysis on outcome of both techniques was performed. More female patients underwent HARP compared to LDN (75% vs. 40%, P = 0.017). Other baseline characteristics were not significantly different. Median operation time and WIT were shorter in HARP (180 vs. 225 min, P = 0.002 and 3 vs. 5 min, P = 0.007 respectively). Blood loss did not differ (200 ml vs.150 ml, P = 0.39). Intra and postoperative complication rates for HARP and LDN (respectively 10% vs. 25%, P = 0.17 and 5% vs. 15%, P = 0.25) were not significantly different. During median follow-up of 18 months estimated glomerular filtration rates in donors and recipients and graft- and recipient survival did not differ between groups. Hand-assisted retroperitoneoscopic donor nephrectomy reduces operation and warm ischemia times, and provides at least equal safety. Hand-assisted retroperitoneoscopic may be a valuable alternative for left-sided LDN.

Background We hypothesized that a high within-patient variability in clearance of tacrolimus and mycophenolate mofetil (MMF) would put patients at risk for periods of over- or underimmunosuppression and would thus lead to long-term chronic allograft nephropathy and graft loss after transplantation. Methods From 297 patients transplanted between 1 January 2000 and 31 December 2004, the within-patient variability in clearance was calculated from tacrolimus whole-blood concentrations and mycophenolic acid (MPA) plasma concentrations drawn between 6 and 12 months post-transplantation. As a primary outcome, a composite end point consisting of graft loss, biopsy-proven chronic allograft nephropathy and 'doubling in plasma creatinine concentration in the period between t = 12 months post-transplantation and last follow-up' was used. Results In the study population of 297 patients, 34 patients reached the primary end point of graft failure. The within-patient variability in the clearance of tacrolimus and three other covariates are significant risk factors for reaching the composite end point of failure [P-values for intraindividual tacrolimus variability = 0.003, biopsy-proven acute rejection (BPAR) = 0.003, recipient age at transplantation = 0.005]. The mean tacrolimus concentration for controls [7.4 (+/- 2.9) ng/mL] and for failures [6.9 (+/- 2.5) ng/mL] was similar. Within-patient variability in the clearance of MPA was not related to reaching the composite end point of failure. Conclusions This study shows a significant relationship between the high within-patient variability in the clearance of tacrolimus, but not for MPA, and long-term graft failure.

Background. Cytomegalovirus seropositivity is associated with an increased risk for cardiovascular disease in end-stage renal disease (ESRD) patients. Circulating pro-inflammatory CD4posCD28null T cells are expanded in cytomegalovirus-seropositive ESRD patients and potentially could mediate atherosclerotic plaque instability and rupture. Methods. In this study, we tested the hypothesis that increased numbers of circulating CD4posCD28null T cells may represent a risk factor for cardiovascular disease in ESRD patients. Prospectively collected data from 240 cytomegalovirus-seropositive stable ESRD patients were analysed. Results. Traditional cardiovascular risk factors (age, smoking, hypercholesterolaemia and diabetes mellitus) and the percentage and absolute number of CD4posCD28null T cells were significantly associated with the presence of atherosclerotic disease, after univariate and multivariate statistical analysis. An similar to 2-3-fold increase in the prevalence of atherosclerotic disease was noted between patients with the highest and lowest number of CD4posCD28null cells. CD8posCD28null T-cell populationswere also significantly expanded in cytomegalovirus-seropositive ESRD patients and closely correlated with the number of CD4posCD28null T cells. However, this cell population was not related to an increased prevalence of cardiovascular disease. Conclusions. Cytomegalovirus- seropositive ESRD patients may have substantially increased numbers of circulating pro-inflammatory CD4posCD28null T cells that are independently associated with the presence of atherosclerotic disease. The expansion of these cells may therefore represent a novel non-traditional cardiovascular risk factor for ESRD patients.

Mesenchymal stromal cells regulate immune cell function via the secretion of soluble factors. Cell membrane interactions between these cell types may play an additional role. Here, we demonstrate that subpopulations of allo-activated T cells are capable of binding to human adipose-derived stromal cells (ASC). The bound T-cell population contained CD8+ T cells and was enriched for CD4-CD8- T cells, whereas the proportion of CD4+ T cells was decreased compared with the non-bound T-cell population. Bound CD4+ T cells had high proliferative activity and increased CD25 and FoxP3 expression. However, they also expressed CD127, excluding regulatory T-cell function. In CD8+ T cells, IL-2 sensitivity, as determined by the analysis of phosphorylated STAT5, was lower in the presence of ASC and even lower in bound cells. In contrast, IL-2-induced phosphorylated STAT5 levels were higher in bound CD4+ T cells than in non-bound CD4+ T cells. Additionally, pro-proliferative TGF-beta signalling via endoglin and SMAD1/5/8 phosphorylation was detected in bound CD4+ T cells. Even after prolonged co-culture with ASC, the activated phenotype of bound CD4+ T cells persisted. In conclusion, these results demonstrate that the binding of lymphocytes to ASC represents an immunomodulatory mechanism in which CD8+ T cells are inhibited in their responsiveness to pro-inflammatory stimuli and reactive CD4+ T cells are depleted from the immune response.

Objectives The active metabolite of mycophenolate mofetil (MMF), mycophenolic acid, inhibits the activity of the target enzyme inosine monophosphate dehydrogenase (IMPDH). The aim of this study was to correlate eight different single nucleotide polymorphisms of the IMPDH type II gene to the activity of the IMPDH enzyme to explain between-patient differences in IMPDH activity. Methods and results In a prospective study, we measured IMPDH activity, mycophenolic acid plasma concentrations, and eight polymorphisms of IMPDH type II in de novo kidney transplant recipients, 6 days posttransplantation while on MMF treatment Polymorphisms in the IMPDH type II gene were only observed for the IMPDH type II 3757T > C (rs11706052) single nucleotide polymorphism. Ten of 101 patients (10%) were heterozygous and two of 101 patients (2%) homozygous for IMPDH type II 3757T > C. The allele frequency was 6.9%. The IMPDH activity over 12 h (AUC(act)) was 49% higher for patients with an IMPDH type II 3757C variant [n = 12 vs. n = 68; 336 (95% confidence interval: 216-521) vs. 227 (95% confidence interval: 198-260) h mu mol/s/mol adenosine monophosphate; P=0.04]. The IMPDH activity measured before transplantation (Act(pre-Tx)) was not significantly different between IMPDH type II 3757TT wild-type and variant carrier patients (P=0.99). Conclusion We report that the IMPDH type II 3757T > C polymorphism is associated with an increased IMPDH activity in MMF-treated renal transplant patients. This polymorphism explains 8.0% of the interpatient variability in IMPDH activity. Pharmacogenetics and Genomics 19:626-634 (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Immune reactivity after HLA-identical living related (LR) kidney transplantation can be caused by minor histocompatibility antigen and non-HLA antigen mismatches between donor and recipient. In our center, HLA-identical LR kidney transplant recipients receive azathioprine (AZA) or mycophenolate mofetil (MMF) in combination with corticosteroids for 1 year after transplantation. Thereafter, AZA or MMF was withdrawn, and the patients were treated with steroid monotherapy as maintenance therapy. We questioned whether withdrawal of AZA or MMF affected the donor-specific lymphocyte proliferation and cytokine production. Donor and third-party T-cell reactivities were determined by mixed lymphocyte reactions and by cytokine production using multiplex bead array technique. The donor and third-party proliferative capacities were not affected after withdrawal of AZA or MMF. Thirteen of 17 cytokines were detected by the multiplex bead array technique. No differences were observed after third-party induced cytokine production after withdrawal of AZA or MMF. However, production of donor-specific interferon-gamma and macrophage inflammatory protein-1 beta increased after discontinuation of AZA or MMF, but no clinically relevant acute rejection was observed. In conclusion, after HLA-identical LR kidney transplantation, donor-specific cytokine responses can be found when AZA or MMF therapy is discontinued. The clinical relevance of this phenomenon is still not evident.

Background. CD4(+)CD25(bright+)FoxP3(+) regulatory T cells are suppressors of antigen-activated immune reactivity. Here, we assessed the clinically relevant role of these cells in the control of immune responses directed to a transplanted heart. Methods. We investigated the phenotype and function of peripheral CD4(+)CD25(bright+)FoxP3(+) T cells in heart transplant patients free from acute rejections (n=9) and in rejectors (n=12) before and during acute cellular rejection. Results. Between rejectors and nonrejectors, the proportion of CD(4+)CD25(bright+) T cells and of FOxP3(+) cells within this population was comparable. Yet, CD(4+)CD25(bright+)FoxP3(+) T cells of rejectors had a higher CD127 expression than those of nonrejectors (P

Background. Human mesenchymal stem cells (MSC) have immunosuppressive capacities. Although their efficacy is currently studied in graft-versus-host disease, their effect on alloreactivity in solid organ transplant patients is unknown. In this study, the immunosuppressive effect of MSC on recipient anti-donor reactivity was examined before and after clinical kidney transplantation. Methods. Anti-donor reactivity was established in pretransplant and posttransplant mixed lymphocyte reactions (MLR) of 14 living-kidney donor-recipient pairs. MSC from donors and third-party controls were added to the MLR in a ratio of 1:5. Results. MSC were isolated from donor perirenal fat and showed multilineage differentiation potential and the capacity to inhibit lymphocyte proliferation. The immunosuppressive effect of MSC was dose dependent and mediated by cell-membrane contact and soluble factors, including interleukin-10 and indoleamine 2,3-dioxygenase. Donor-derived MSC significantly inhibited the recipient anti-donor reactivity before and 1 month after transplantation. This effect was independent of human leukocyte antigen background of MSC. Flow cytometric analysis showed that MSC inhibited the proliferation of CD4(+) and CD8(+) T-lymphocyte subsets in pretransplant and posttransplant donor-directed MLR, whereas MSC had no effect on B- or natural killer-cell proliferation. Conclusion. Donor MSC significantly inhibited the proliferation of alloactivated recipient T cells before and after kidney transplantation. We believe these findings should encourage MSC-based intervention in clinical organ transplantation.

Background. Living-related (LR) human leukocyte antigen (HLA)-identical renal transplant (RTx) recipients often receive standard immunosuppression, despite the absence of mismatched major HLA-antigens and the known complications of long-term use of immunosuppression. No data are available on the need for immunosuppression for these specific patients. We wondered whether their immunosuppressive load could be radically reduced. Method. Between November 1982 and November 2005, 83 LR HLA-identical RTx were performed in our center. Their unadjusted graft survival was 74% at 10 years. In 29 patients (median time after transplantation 5.6 [range 1.0-21.4] years) with stable uncompromised renal function, we tapered their immunosuppression from triple or dual therapy to prednisolone 5 mg/day. Follow up on prednisolone monotherapy was at least 24 months. Results. In 27 of 29 patients reduction of immunosuppression to prednisolone monotherapy was uneventful. One patient, using dual therapy, developed JC-virus nephropathy resulting in graft loss. One refused further discontinuation of his medication. Four (15%) of the 27 patients on monotherapy developed biopsy-proven recurrence of their original disease. Only one of them showed a transient decline in renal function. One additional patient developed minor proteinuria and a rise in serum creatinine level, as a result of chronic urinary tract infections. The remaining 23 of 27 patients (85%) had an uneventful follow up during 24 months prednisolone monotherapy. Conclusion. We conclude that HLA-identical LR RTx recipients who are at least 1 year after transplantation might be treated with low-dose steroid monotherapy. Close surveillance of patients for recurrence of their original disease is recommended to allow for potential early therapeutic intervention.

In Europe, living kidney donation rates differ considerably from country to country. These differences are related to deceased kidney donation rates: countries with higher deceased donation rates have lower living donation rates. Despite the differences, all Countries have one thing in common, namely, the shortage of kidneys for transplantation. Living kidney donation is a good option to alleviate these shortages. In our center, 60% to 70% of all kidney transplants come from living donors. This article describes various strategies that may have contributed to these high living donation rates: learn attitude, educational materials and meetings, and alternative donation programs (exchange donation, domino-paired donation, Good Samaritan donation). Also described are some less conventional strategies for increasing rate of living kidney donation that are not used in the Netherlands but may offer some good perspectives (eg, the "Norwegian approach" and home-based educational programs). (Progress in Transplantation. 2009; 19:71-75)

Background. Prevention of alloreactivity by rabbit anti-thymocyte globulins (rATG) may not only result from immunodepletion but also from the induction of T cells that control allogeneic immune responses. In the present prospective and controlled study, we investigated the effect of rATG on the frequency, function and phenotype of peripheral immunoregulatory CD4(+) T cells in kidney transplant (KTx) patients. Methods. After transplantation, 16 patients received ATG-induction therapy and triple therapy consisting of tacrolimus, MMF and steroids. The control group (n = 18) received triple therapy only. By flow cytometry, T cells were analysed for CD25, FoxP3, CD127, CD45RO and CCR7. To study their suppressive capacities, CD25(bright) T cells were co-cultured with CD25(-/dim) effector T cells (Teff) in mixed lymphocyte reactions (MLR), stimulated with donor and third party (3P) antigens. Results. Pre-transplant levels of FoxP3(+)CD127(-/low) T cells were 6% of CD4(+) T cells. One week post-ATG treatment, no measurable numbers of regulatory T cells were present (P < 0.01). After 4 weeks, the cell numbers of CD4(+)FoxP3(+)CD127(-/low) T cells slowly reappeared and thereafter remained low (P < 0.01). At 14 weeks, a significant shift towards the CD45RO(+)CCR7(+) (central memory) phenotype within CD4(+)FoxP3(+) T cells was observed (P < 0.01). At 26 weeks, the proliferative alloresponses of the PBMC and CD25(-/dim) Teff profoundly decreased compared to pre-transplant (P = 0.01 and P = 0.02 respectively), while the regulatory capacity of the CD25(bright) T cells, of which 90% consisted of FoxP3(+)CD127(-/low) T cells, remained unaffected. The CD25(bright) T cells suppressed the anti-donor (94%) and 3P responses (93%). Conclusion. Our findings show that rATG therapy does not spare peripheral immunoregulatory T cells in vivo, but after regeneration preserves their suppressive activity.

We evaluated whether the regulatory function of CD4(+)CD25(high+)FoxP3(+) T-cells from patients on tacrolimus and mycophenolate mofetil (MMF) is affected by preceding steroid and anti-CD25 mAb induction therapy and whether this function is associated with rejection after kidney transplantation. Kidney recipients (N=15) were randomized to receive either anti-CD25 mAb induction (i.e., daclizumab) or steroids for 4 months. We analyzed the presence and suppressive activity of CD4(+)CD25(high+)FoxP3(+) peripheral T-cells in samples obtained at pre and 4-6 months after transplantation. Anti-CD25 mAb therapy and treatment with steroids did not significantly affect protein expression of FoxP3. However, at the functional level, significant differences were found in the regulatory activities of CD4(+)CD25(high+) T-cells from the anti-CD25 group vs those from the steroid group. At 4-6 months after transplantation, the regulatory activities of CD4(+)CD25(high+) T-cells were comparable to those before anti-CD25 mAb therapy; 49 +/- 13% (mean +/- SEM) vs 40 +/- 14% at a 1:20 ratio (CD25(high+):CD25(-/dim)), respectively. In contrast, the regulatory capacities of CD(+)D25(bright+) T-cells from the steroid patient group became significantly impaired. The percentage inhibition of the anti-donor response decreased from 57 +/- 12% before transplantation to 12 +/- 7% after transplantation (p

Background In many transplant centers, human leukocyte antigen (HLA)-identical living-related (LR) renal transplant recipients receive standard maintenance immunosuppression from 1 year after transplantation. We questioned whether discontinuation of azathioprine (AZA) or mycophenolate mofetil (MMF) influenced T-cell reactivity, circulating dendritic cell (DC) subsets numbers and their maturation status. Methods Twenty-nine HLA-identical LR renal transplant recipients were withdrawn from AZA or MMF. Thereafter, the patients received only prednisolone. T-cell reactivity was determined by interferon-gamma (n=23), interleukin (IL)-10 (n=16), and granzyme B (n=10) Elispot assays. Circulating DC subset numbers and their maturation status determined by CCR2, CCR5, CCR7, and CD83 expression were measured by flow cytometry (n=12). Results The number of donor, third-party, and tetanus toxoid-reactive interferon-gamma and granzyme-B producing cells was not affected after withdrawal of immunosuppression. Discontinuation of AZA or MMF resulted in significant increased numbers of third-party (P=0.003) and tetanus toxoid-reactive (P=0.008) IL-10 producing cells, and a trend in higher numbers of donor-reactive IL-10 producing cells (P=0.06). No effect was found on the number of circulating DC subsets, but DC was shifted toward a more mature phenotype. Conclusions In HLA-identical LR renal transplant recipients, therapy with AZA and MMF suppress the IL-10 production and the maturation of DC. This suggests that these immunosuppressants may hinder suppression of immune responses in general, including allogeneic responses.

Background. We previously reported that no cytotoxic T-lymphocyte precursor frequencies (CTLpf) were found in 60% of patients on azathioprine or mycophenolate mofetil+Pred long after kidney transplantation. We questioned whether the absence of donor-specific CTLpf was associated with low levels Of stimulator), Th1 (tumor necrosis factor [TNF]-alpha, interferon [IFN]-gamma) or high levels of regulatory Th2 (interleukin [IL]-4, IL-6, IL-10) cytokines. Methods. In this study, peripheral blood monocyte cells (PBMC) were stimulated with irradiated donor cells. After 7 days, cytokine production was determined by cytokine bead array, and CTLpf by limiting dilution assay. Results. Patients with detectable CTLpf (>= 10/10(6) PBMC) had significantly higher levels of TNF-alpha (P=0.04) and IFN-gamma (P=0.02) than patients with nondetectable CTLpf (

P>CD4(+) CD25(bright+) FoxP3(+) regulatory T cells (Tregs) may control donor-specific allogeneic responses in kidney transplant recipients. Recent evidence demonstrated that three phenotypical Treg-subsets, naive (CCR7(+)CD45RO(-)), central-memory (CCR7(+)CD45RO(+)) and effector-memory (CCR7(-)CD45RO(+)), are essential for the development and function of antigen-specific suppression in the lymphoid and peripheral tissues. Also, it has been appreciated that Tregs are affected by immunosuppressive agents. In clinical practice, however, the effect of a single drug remains to be determined. Therefore, we analyzed the effect of several immunosuppressive agents on the number, phenotype and function of peripheral Tregs from 46 stable kidney transplant recipients. These patients were converted to monotherapy with tacrolimus (n = 15), rapamycin (n = 17) or mycophenolate mofetil (n = 14). Blood was obtained at inclusion and 6 months thereafter. The number of Tregs increased significantly in patients on monotherapy with rapamycin (P < 0.001), which was caused by increased numbers of Tregs with a central-memory and an effector-memory phenotype (both P < 0.05). At 6 months after conversion, however, the suppressive function of Tregs did not significantly change in co-cultures stimulated with donor-Ag. Therefore, monotherapy with rapamycin allows the signals that are needed to increase the number of functional Tregs with a memory phenotype, thereby enhancing the potential capacity to regulate donor-specific responses in the lymphoid and the peripheral tissues.

Cytomegalovirus (CMV)-seropositive patients with ESRD may have more CD4(+) T cells lacking the co-stimulatory molecule CD28 (CD4(+)CD28null) than CMV-seronegative patients. Increased numbers of CD28null T cells associates with epoetin nonresponsiveness in patients with ESRD, but whether expansion of CD4+CD28null T cells in CMV-seropositive patients associates with demand for epoetin is unknown. In a cohort of 129 stable patients with ESRD, CMV seropositivity significantly associated with a lower hemoglobin level in predialysis patients (12.5 versus 11.5 g/dl; P < 0.02). CMV seropositivity did not associate with average hemoglobin level in hemodialysis patients, but CMV-seropositive patients required significantly more epoetin (median 12,000 versus 6300 U/wk; P = 0.02). Multivariate linear regression analysis identified CMV seropositivity as the only variable significantly associated with hemoglobin levels in predialysis patients and epoetin dosages in hemodialysis patients. In CMV-seropositive hemodialysis patients, the number of circulating CD4(+)CD28null T cells positively correlated with epoetin dosage. These CD4(+)CD28null T cells were proinflammatory; they were capable of producing large amounts of IFN-gamma and TNF-alpha. In conclusion, expansion of CD4(+)CD28null T cells in CMV-seropositive patients with ESRD associates with increased demand for epoetin.

Purpose of review As the knowledge of CD4(+)CD25(bright+)FoxP3(+) regulatory T cells in experimental transplant models grows, we need to understand how and to what extent these suppressor cells regulate donor-directed immune events in the transplantation clinic. pp This review focuses on the function of regulatory T cells in the peripheral blood and the transplanted organ of patients after heart transplantation during immunological quiescence and rejection. Recent findings Here, we present data that peripheral CD4(+)CD25(bright+)FoxP3(+) T cells of heart transplant patients who experience acute rejection have inadequate immune regulatory function in vitro compared with those of nonrejecting patients. During rejection, potent donor-specific T-cell suppressors are present in the transplanted organ. Summary The studies in transplant patients' show that the function of CD4(+)CD25(bright+)FoxP3(+) regulatory T cells in alloimmunity is to inhibit the activation of effector T cells, to prevent rejection, and to control the antidonor response at the graft itself at later stages of immune reactivity.

Contains fulltext : 81930.pdf (Publisher’s version ) (Closed access) BACKGROUND: Female renal transplant candidates are prone to be sensitized by prior pregnancies, and undetected historical sensitization might decrease transplantation outcome. Hypothesis of our study was that pre-transplant blood transfusions (PTFs) can elucidate historical sensitization and that the avoidance of the associated antigens can improve transplantation outcome. METHODS: Data from all female non-immunized renal transplant candidates who received a random PTF (rPTF) (n = 620), matched PTF (mPTF) (one HLA-A and B and one HLA-DR match) (n = 86) or donor-specific blood transfusion (DST) (n = 100) between 1996 and 2006 were collected. Complement-dependent cytoxicity was used to detect anti-HLA antibodies. Sensitization and transplantation outcomes after a PTF were analyzed. Non-immunized female renal transplant recipients who did not receive a PTF were used as the control group. RESULTS: In 165 patients, anti-HLA antibodies (IgG) were detected after the PTF. Both historical and primary sensitizations were found. A DST induced donor-specific anti-HLA antibodies in 25% of the DST recipients. Our policy did not improve transplantation outcome in recipients of a kidney from a deceased donor (n = 368) or in recipients of a living donor [DST (n = 49) and mPTF (n = 66)]. CONCLUSIONS: A PTF did elucidate historical sensitization but induce primary sensitization as well. No beneficial effect of PTFs on transplantation outcome was found, and PTFs with the intention to detect historical sensitization are therefore not suggested.

Background: It has been reported that donor-reactive T-cell responses may decrease during the first year after HLA-mismatched organ transplantation. We wondered whether donor-reactive T-cell responses directed to minor histocompatibility antigens (mHAgs) or other non-HLA antigens also decrease after HLA-identical living-related (LR) kidney transplantation. Methods: We studied donor-reactive T-cell responses by IFN-γ and granzyme B (GrB) Elispot assays in 15 HLA-identical LR kidney transplant recipients before, six months and one yr after transplantation. Third-party reactivity was used as control. Patient and donor peripheral blood mononuclear cells were typed for 11 known mHAgs. Results: During the study period, 60% and 36% of the patients demonstrated donor-reactive IFN-γ and GrB producing cells (pc), respectively. The number of donor-reactive IFN-γ and GrB pc was significantly lower than the number of third-party reactive IFN-γ and GrB pc. After transplantation, donor-reactivity and third-party reactivity were comparable to pre-transplant values. No relation was found in mHAg mismatches between donor and recipient and donor-reactive T-cell response. Conclusions: Donor-reactivity could be detected before and after HLA-identical LR kidney transplantation, but was not related with the number of mHAg mismatches, and did not decrease after transplantation.

Introduction. CP-690,550 inhibits Janus kinase 3 (JAK3) which mediates signal transduction of receptors of the common gamma-chain cytokines. These cytokines play key roles in lymphocyte function and homeostasis. As part of a phase 1 trial, we evaluated the effect of CP-690,550 on immune parameters. Material. Stable kidney transplant recipients (n=8) receiving mycophenolate mofetil and prednisolone were treated with CP-690,550, 30 mg twice daily orally for 29 days. Blood samples were collected oil days 1 (before first dose), 15, 29 (end of treatment), and 57. Results. Two patients experienced minor infections (One urinary tract infection and one mild respirator), tract infection). Leukocyte counts remained stable, whereas a mean decrease in hemoglobulin of 8% was measured (P=0.01). CP-690,550 treatment for 29 days resulted in statistically significant changes in the number of circulating CD19(+) B cells (P=0.05), CD3(-)CD16(+)CD56(+) natural killer-cells (P

Mesenchymal stem cells (MSC) are characterized by their multilineage differentiation capacity and immunosuppressive properties. They are resident in virtually all tissues and we have recently characterized MSC from the human heart. Clinical heart transplantation offers a model to study the fate of transplanted human MSC. In this study, we isolated and expanded MSC from heart tissue taken before, and 1 week up to 6 years after heart transplantation. MSC from posttransplantation tissue were all of donor origin, demonstrating the longevity of endogenous MSC and suggesting an absence of immigration of recipient MSC into the heart. MSC isolated from transplanted tissue showed an immunophenotype that was characteristic for MSC and maintained cardiomyogenic and osteogenic differentiation capacity. They furthermore preserved their ability to inhibit the proliferative response of donor-stimulated recipient peripheral blood mononuclear cells. In conclusion, functional MSC of donor origin remain present in the heart for several years after transplantation.

Measurement of the pharmacodynamic biomarker inosine monophosphate dehydrogenase (IMPDH) activity in renal transplant recipients has been proposed to reflect the biological effect better than using pharmacokinetic parameters to monitor mycophenolate mofetil therapy, The IMPDH assays are however labor intensive and this complicates implementation into patient care. Quantification of IMPDH messenger RNA (mRNA) could form an attractive alternative. This study was designed to correlate IMPDH mRNA levels with IMPDH activity and clinical outcome in renal transplant recipients. From a cohort of 101 renal transplant patients, blood samples were drawn pre transplantation and at 4 times after transplantation. IMPDH activity, IMPDH type 1 and type 2 mRNA levels, and mycophenolic acid concentrations were measured and correlated to clinical outcomes. No correlation was found between IMPDH type 1 and type 2 mRNA levels and IMPDH activity in pre- and posttransplant samples. A significant increase in IMPDH mRNA levels was found between day 6 and day 140 after transplantation. IMPDH type 1 and type 2 mRNA levels before transplant showed a trend toward statistically significant higher levels in patients with an acute rejection (P = 0.052 and P = 0.058). After transplant, the IMPDH type 1 and type 2 mRNA levels were significantly lower in patients with an acute rejection (P = 0.026 and P = 0.007). We conclude that IMPDH mRNA levels do not correlate with IMPDH activity but are nevertheless correlated with acute rejections. Furthermore, although the regulation of the expression of the 2 isoforms is presumed to be different, in this study, the changes in the expression of type 1 mRNA closely paralleled those of type 2.

Over the last decade, there has been a rising interest in the use of mesenchymal stem cells (MSCs) for clinical applications. This interest stems from the beneficial properties of MSCs, which include multi-lineage differentiation and immunosuppressive ability, suggesting there is a role for MSC therapy for tissue regeneration and in immunologic disease. Despite recent clinical trials investigating the use of MSCs in treating immune-mediated disease, their applicability in solid-organ transplantation is still unknown. In this review, we identified topics that are important when considering MSC therapy in clinical organ transplantation. Whereas, from other clinical studies, it would appear that administration of MSCs is safe, issues like dosing, timing, route of administration, and in particular the use of autologous or donor-derived MSCs may be of crucial importance for the functional outcome of MSCs treatment in organ transplantation. We discuss these topics and assess the feasibility of MSCs therapy in organ transplantation.

Background: Dysregulation of dendritic cell (DC) mediated immune responses towards auto-antigens, is considered an important feature in the maintenance of experimentally induced heart failure (HF). In order to evaluate the role of blood DCs in cardiomyopathies of different origins, we examined myeloid (mDC) and plasmacytoid (pDC) subset levels and maturation characteristics, according to HF severity and etiology in humans. Methods: Absolute numbers of mDCs and pDCs in 12 New York Heart Association (NYHA) class-II, 28 NYHA class III-IV HF patients and 18 healthy controls, were studied by 4-colour whole blood flow cytometry. Results: End-stage (NYHA III-IV) HF patients had comparable circulating DC subset levels to NYHA-II patients and controls. However, within the NYHA III-IV group total DC levels in patients with non-ischemic dilated cardiomyopathy (DCM) were higher (P

Objective: Kidney transplantation with a living donor has proved to be an effective solution for kidney patients on the waiting list for transplantation. Nevertheless, it may be difficult to find a living kidney donor. The purpose of this explorative study is to investigate how kidney transplant candidates may, or may not, find a living donor in the Netherlands. Methods: We compared a group of 42 patients who did not find a living donor with a group of 42 patients who did, using semi-structured interviews. Results: We found that, although almost all patients recognized the advantages of living kidney donation and were willing to accept the offer of a living kidney donor, many found it very difficult to ask a potential donor directly. This was true for both groups. Conclusion: Patients may gain from professional support to deal with this situation in ways that balance their medical needs and their personal relationships. Practice Implications: Support programs should be developed to assist patients in developing strategies for discussing living kidney donation with potential donors. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

Background. The defensive immune system in patients with end-stage renal failure is impaired at multiple levels. This state of immune incompetence is associated with continuous activation of the immune system. An additional explanation for this state of activation may be the disturbed function of CD4(+)CD25(bright+)FoxP3(+) regulatory T-cells. Methods. The phenotype and function of peripheral regulatory T-cells from patients with end-stage renal failure (N = 80) and healthy controls (N = 17) was studied by flow cytometry, RT-PCR and mixed lymphocyte reaction. Patients were on haemodialysis (N = 40), peritoneal dialysis (N = 26) or not treated with dialysis yet (N = 14). The latter group had a glomerular filtration rate of < 20 ml/min/ 1.73 m(2). Results. The basal IL-2 mRNA level was high in patient-PBMC (P = 0.0002 versus healthy controls). The absolute number of CD4(+)CD25(bright+) T-cells was low in patients (P < 0.05 versus healthy controls). Furthermore, proliferation of patient-PBMC upon allogeneic stimulation was impaired (P < 0.0001 versus healthy controls). The regulatory function of CD4(+)CD25(bright+) T-cells was determined in the setting of direct allorecognition. First, the effect of depletion of CD25(bright+) cells from patient-PBMC on proliferation was low. Second, co-culture of CD25(bright+) cells with CD25(neg/dim) cells (1:10 ratio) showed impaired regulatory function (P < 0.001 versus healthy controls), which was especially pronounced in patients on dialysis. The FOXP3 mRNA level was also low upon stimulation (P = 0.0002 versus healthy controls). Conclusions. In line with previous studies, we observed an overactivated but functionally compromised immune system in patients with end-stage renal failure. It now appears that in this setting, regulation by CD4(+)CD25(bright+)FoxP3(+) T-cells is also impaired.

Contains fulltext : 69969.pdf (Publisher’s version ) (Closed access) The prevalence of cardiovascular risk factors in renal transplant candidates is high. A better understanding of the relation between these risk factors and cardiovascular morbidity and mortality is mandatory to improve transplantation outcome. In this retrospective cohort study 2187 adult patients who received a first kidney transplant between 1984 and 1997 were included. We analyzed the incidence of post-transplant cardiovascular events and tried to identify independent pretransplant risk factors for post-transplant cardiovascular events and all-cause mortality. The cumulative incidence of post-transplant cardiovascular events was 40%. The incidence was highest in the first 3 months after transplantation. Independent pretransplant risk factors for a post-transplant cardiovascular event were diabetic nephropathy [Hazard ratio (HR) 3.02; 95% CI 2.85-3.98], claudication [HR 2.17 (1.42-3.31)], cardiac event [HR 1.76 (1.32-2.33)], cerebrovascular accident HR 1.53 (1.03-2.28), time-on-dialysis [HR 1.06 (1.02-1.11)], recipient age [HR 1.04 (1.04-1.05)], and body mass index [HR 1.03 (1.00-1.05)]. Diabetic nephropathy and cardiovascular disease were also important predictors for all-cause mortality. Diabetic nephropathy and cardiovascular disease were the most important predictors for cardiovascular events and all-cause mortality after renal transplantation. Early treatment of cardiovascular risk factors and pretransplant cardiovascular evaluation might improve transplantation outcome.

Background: The role of CD4+ CD25bright regulatory T cells (Treg) in controlling alloreactivity is established, but little is known whether antigen-specific Treg are induced in fully immunosuppressed kidney transplant patients. Methods: The frequency and function of CD25bright T cells of nine stable kidney transplant patients before and 0.5–2 yr after transplantation were measured. Patients received triple therapy consisting of cyclosporine, mycophenolate mofetil and prednisone. To investigate the influence of transplantation and immunosuppression on Treg function, we compared their suppressive capacities pre- and post-transplantation using mixed lymphocyte reactions and kept the CD25−/dim effector T-cell (Teff) population constant. Results: After transplantation, the percentage of CD4+ CD25bright T cells significantly decreased from 8.5% pre-transplant to 6.9% post-transplant (median, p = 0.05). However, the lower percentage of post-transplant CD4+ CD25bright T cells was not associated with reduced, but rather improved suppressor function of these cells. The proliferative response of pre-transplant Teff to donor-antigens was more profoundly suppressed by post-transplant Treg than by pre-transplant Treg (pre-transplant 18% vs. post-transplant 55% median, p = 0.03) and was comparable against third party antigens at a CD25bright:CD25−/dim ratio of 1:20. Conclusions: In immunosuppressed kidney transplant patients, the donor-directed suppressive capacity of CD4+ CD25bright regulatory T cells improved, which may contribute to the development of donor-specific hyporesponsiveness against the graft.

Background. After HLA-identical living-related (LR) kidney transplantation, only non-HLA antigen mismatches between donor and recipient may exist. We questioned whether donor-reactive responses against non-HLA antigens could be found after HLA-identical LR kidney transplantation, and wondered whether donor reactivity in the HLA-identical setting was different from the HLA-mismatched setting during immunological quiescence. Healthy individuals served as controls. Methods. Elispot assays were performed to determine the number of alloreactive IFN-gamma-producing cells (pc), IL-10 pc, granzyme B (GrB) pc and IL-13 pc from peripheral blood mononuclear cells (PBMC) of HLA-identical, HLA-mismatched LR kidney transplant recipients and healthy individuals. Results. The frequency of alloreactive IFN-gamma pc, IL-13 pc and GrB pc was higher in healthy individuals compared to both transplant patient groups. In the HLA-identical group, significantly higher numbers of donor-reactive IL-10 pc were found compared to their autologous control. These frequencies were also higher compared to the HLA-mismatched and healthy control group. The number of donor-reactive GrB pc was higher in the HLA-mismatched group than in the HLA-identical group. Donor-reactive IFN-gamma pc and IL-13 pc were comparable in both transplant groups. Conclusions. In recipients of HLA-identical LR kidney transplant, high donor-reactive IL-10 pc, in combination with low donor-reactive IFN-gamma pc, IL-13 pc and GrB pc, suggests active downregulation of reactivity against non-HLA molecules.

The role of regulatory T cells in the induction and maintenance of transplant tolerance has been widely investigated in experimental animal models. Their involvement in the regulation of allogeneic immune reactivity in immunosuppressed organ transplant patients, however, remains unclear. Measurements of regulatory T cells after clinical organ transplantation may contribute to understanding their role in anti-donor immune responses. Several studies have investigated the frequency and/or immune regulatory function of peripheral regulatory T-cell populations, such as, the CD4(+)CD25(+) regulatory T cells or the CD8(+)CD28(-) suppressor T cells, in clinically stable organ transplant patients and patients with acute or chronic rejection. This review summarizes these studies and discusses the correlations found between the number and function of regulatory T cells and the immunological state of the patient. This knowledge is warranted for a better understanding of the control of allogeneic immune responses by regulatory T cells. Subsequently, monitoring regulatory T cells may help us to identify patients in whom the anti-donor reactivity is actively suppressed.