Initiation of hemodialysis treatment leads to improvement of T-cell activation in patients with end-stage renal disease

Efficacy of pre-emptive kidney transplantation for adults with end-stage kidney disease: a systematic review and meta-analysis

BACKGROUND

Pre-emptive kidney transplantation (PEKT), i.e., transplantation performed before initiation of maintenance dialysis, is considered an ideal renal replacement therapy because there is no exposure to long-term dialysis therapy. Therefore, we summarized advantages/disadvantages of PEKT to assist in deciding whether kidney transplantation should be performed pre-emptively.

METHODS

This study was registered with PROSPERO, CRD42021269163. Observational studies comparing clinical outcomes between PEKT and non-PEKT were included; those involving only pediatric recipients or simultaneous multi-organ transplantations were excluded. The PubMed/MEDLINE, Cochrane Library, and Ichushi-Web databases were searched on 1 August 2021. Studies were pooled using the generic inverse-variance method with random effects model, and risk of bias was assessed using ROBINS-I.

RESULTS

Seventy-six studies were included in the systematic review (sample size, 23-121,853; enrollment year, 1968-2019). PEKT patients had lower all-cause mortality (adjusted HR: 0.78 [95% CI 0.66-0.92]), and lower death-censored graft failure (0.81 [0.67-0.98]). Unadjusted RRs for the following outcomes were comparable between the two patient groups: cardiovascular disease, 0.90 (0.58-1.40); biopsy-proven acute rejection, 0.75 (0.55-1.03); cytomegalovirus infection, 1.04 (0.85-1.29); and urinary tract infection, 0.89 (0.61-1.29). Mean differences in post-transplant QOL score were comparable in both groups. The certainty of evidence for mortality and graft failure was moderate and that for other outcomes was very low following the GRADE classification.

CONCLUSIONS

The present meta-analysis shows the potential benefits of PEKT, especially regarding patient and graft survival, and therefore PEKT is recommended for adults with end-stage kidney disease.

Renal function deterioration is an independent mortality determinant in Koreans diagnosed with lupus nephritis

OBJECTIVE

To evaluate the predictors of mortality, mortality rate, and causes of death in patients with lupus nephritis (LN) depending on final renal function.

METHODS

The cohort included 401 Korean patients diagnosed with LN between 1985 and 2019. We retrospectively analyzed the clinical and laboratory indices, treatment response, and the final renal function. The final renal function was defined by the last stable level of eGFR measured in an out-patient department more than 3 times before death occurred and was categorized into five groups depending on CKD stage.

RESULTS

The median follow-up time after the diagnosis of LN was 131 months. No difference in baseline demographic characteristics and laboratory findings was found except for the proportion of Hb less than 10 mg/dl and baseline eGFR (p = 0.011 and 0.037). We found no significant differences in therapeutic parameters, but all the response parameters including treatment response at 6 months (p = 0.004) and 12 months (p = 0.004), time to remission (p < 0.001), final renal response (p < 0.001), and the final renal function (p < 0.001) differed significantly between the two groups. In multivariate Cox proportional hazards analysis, the final renal function was an independent risk factor predicting mortality. The main causes of death were infection and SLE flare. Contrary to existing knowledge, SLE flare also triggered mortality in a few patients with LN progressed to end-stage renal disease (ESRD). Only two cases of mortality occurred in the kidney transplantation (KT) group (n = 25) with a median follow-up period of 224 months. The overall mortality rates calculated using the Kaplan-Meier method were 6.8%, 10.3%, 19.7%, and 28.0% at 5, 10, 20, and 30 years, respectively.

CONCLUSION

Renal function deterioration was an independent determinant of mortality in Korean patients with LN. SLE flare also caused mortality in patients with LN who required maintenance dialysis, suggesting the benefit of KT on lupus activity and survival.

Immune reconstitution inflammatory syndrome in the lung in non-human immunodeficiency virus patients

BACKGROUND

We evaluated immune reconstitution inflammatory syndrome (IRIS) in the lung in non-human immunodeficiency virus (HIV) patients.

METHODS

We reviewed articles related to IRIS occurrence in the lung in non-HIV patients using a PubMed search. The keywords used for the search were "immune reconstitution syndrome" and "non-HIV." Only patients with lung involvement were included. Those with suggested IRIS caused by white blood cell recovery were excluded.

RESULTS

There were 37 cases of IRIS in the lung in non-HIV patients. Complicating infections included tuberculosis (n = 17), histoplasmosis (n = 9), aspergillosis (n = 5), cryptococcosis (n = 4), and Pneumocystis pneumonia (n = 2). We also evaluated the underlying diseases, IRIS pathogenesis, management, and prognosis. IRIS was most commonly encountered in patients treated with anti-tumor necrosis factor (TNF) antibody who developed disseminated or extrapulmonary tuberculosis, leading to treatment discontinuation.

CONCLUSIONS

The diagnosis and management of IRIS in the lung in non-HIV patients should be investigated further, especially in the era of anti-TNF treatment.

Perioperative Comparison of Preemptive and Non-Preemptive Renal Transplant Recipients

Objective

Preemptive transplantation cannot be performed for all patients because of the limited number of donors. This study aimed to evaluate the perioperative effects of dialysis before renal transplantation.

Methods

In this study, we retrospectively investigated 666 patients who underwent kidney transplantation at our centre. We divided patients into two groups: patients with pre-transplant dialysis (67.3%, n=448) and patients with preemptive transplant (32.7%, n=218). We carried out preoperative, intraoperative and postoperative comparisons between groups.

Results

No difference was observed in terms of intraoperative blood transfusion, crystalloid and colloid requirement, inotropic-vasopressor agent administration and hemodynamic parameters between the patients with pre-transplant dialysis and preemptive transplant. It was observed that dialysis requirement, delayed graft function and acute rejection development were significantly higher during the postoperative period in patients who underwent dialysis before transplantation. In patients with non-preemptive transplant, the decrease of serum creatinine levels at the first postoperative month was more prominent when compared to patients with preemptive transplant; however, that difference disappeared in the first year follow-up. No significant difference was found for serum albumin levels and proteinuria alterations of the patients in long-term follow-up. Additionally, patient and graft survival comparisons between patients with non-preemptive and preemptive transplant on three-year follow-up revealed no significant difference.

Conclusion

We think that preemptive transplantation treatment is a better option for patients with end-stage renal failure since patients with preemptive transplantation appear to have less metabolic function impairment, complication risk and more successful outcomes in terms of cost-effectiveness.

Evaluation of Serum Interleukin-6 Levels in the Renal Transplant Recipients: A Systematic Review and Meta-Analysis of Case-Control Studies

AIM:

The purpose of this meta-analysis was the assessment of the serum IL-6 levels in the renal transplant recipients compared to the healthy controls.

MATERIAL AND METHODS:

Four databases including PubMed, Web of Science, Scopus, and Cochrane Library were searched up to July 2018 without language restriction. The quality of studies was evaluated using the Newcastle-Ottawa scale (NOS). A continuous random-effects meta-analysis was used by RevMan 5.3 using the mean difference (MD) and 95% confidence intervals (CIs). Also, a regression model was done by Comprehensive Meta-Analysis version 2 (CMA v2).

RESULTS:

Out of 615 studies identified in the databases, 15 studies included and analysed in the meta-analysis. The studies were reported from 1994 to 2018. The meta-analysis included 1035 renal transplant recipients and 682 healthy controls. The pooled MD of the serum IL-6 levels in the transplant recipients compared to the healthy controls was 3.25 pg/mL [95%CI: 2.17, 4.32; P < 0.00001; I2 = 98% (P < 0.00001)]. Meta-regression analysis showed that one of the reasons of heterogeneity is the year of publication (Correlation coefficient (r) = 0.208, p-value = 0.00002).

CONCLUSION:

An elevated serum IL-6 level in the renal transplant recipients compared to the healthy controls showed that the serum level of this marker could be used for the evaluation of inflammation in ESRD patients undergoing renal transplantation.

High soluble CD30 levels and associated anti-HLA antibodies in patients with failed renal allografts

INTRODUCTION

Serum soluble CD30 (sCD30), a 120-kD glycoprotein that belongs to the tumor necrosis factor receptor family, has been suggested as a marker of rejection in kidney transplant patients. The aim of this study was to evaluate the relationship between sCD30 levels and anti-HLA antibodies, and to compare sCD30 levels in patients undergoing hemodialysis (HD) with and without failed renal allografts and transplant recipients with functioning grafts.

METHODS

100 patients undergoing HD with failed grafts (group 1), 100 patients undergoing HD who had never undergone transplantation (group 2), and 100 kidney transplant recipients (group 3) were included in this study. Associations of serum sCD30 levels and anti-HLA antibody status were analyzed in these groups.

RESULTS

The sCD30 levels of group 1 and group 2 (154 ± 71 U/mL and 103 ± 55 U/mL, respectively) were significantly higher than those of the transplant recipients (group 3) (39 ± 21 U/mL) (p&lt;0.001 and p&lt;0.001). The serum sCD30 levels in group 1 (154 ± 71 U/mL) were also significantly higher than group 2 (103 ± 55 U/mL) (p&lt;0.001). Anti-HLA antibodies were detected in 81 (81%) and 5 (5%) of patients in groups 1 and 2, respectively (p&lt;0.001). When multiple regression analysis was performed to predict sCD30 levels, the independent variables in group 1 were the presence of class I anti-HLA antibodies (β = 0.295; p = 0.003) and age (β = -0.272; p = 0.005), and serum creatinine (β = 0.218; p = 0.027) and presence of class II anti-HLA antibodies (standardized β = 0.194; p = 0.046) in group 3.

CONCLUSIONS

Higher sCD30 levels and anti-HLA antibodies in patients undergoing HD with failed renal allografts may be related to higher inflammatory status in these patients.

Preemptive Living Donor Kidney Transplantation and Kidney Function at the Initial Hospital Visit: A Single-Center Case-Control Study

BACKGROUND

Studies have revealed that patients who undergo preemptive kidney transplantation (PKT) have favorable prognoses compared with those who undergo kidney transplantation after the initiation of dialysis. The number of PKT cases performed worldwide has been increasing. The goal of this study was to determine the clinical characteristics of patients who may successfully receive PKT.

METHODS

A single-center, case-control study was conducted to determine the clinical factors that lead to referral for PKT.

RESULTS

Between April 1, 2009, and August 1, 2015, a total of 118 patients underwent living donor kidney transplantation. Thirty of these patients had not undergone dialysis before their initial visit to the study hospital. Of these, 20 received kidney transplantation before and after dialysis initiation, respectively (group PKT+, successful PKT; group PKT-, failed PKT). The baseline characteristics at the primary visit were compared between groups. The median duration from the first visit to the study institution to PKT was 5.6 ± 0.7 months. Serum creatinine (Cr) levels differed significantly between groups (PKT+ vs PKT-, 6.0 ± 0.3 mg/dL vs 7.5 ± 0.5 mg/dL; P = .03). The receiver-operating characteristic curves revealed that a serum Cr level >5.7 mg/dL at the initial visit to the unit was a cutoff point for predicting the success of PKT (area under the curve, 0.721; P = .02).

CONCLUSIONS

Our results indicate that PKT should be performed within ∼6 months of the initial visit to the transplant center. Serum Cr levels <5.7 mg/dL predict successful PKT.

Changes of immunogenic profiles between a single dose and one booster influenza vaccination in hemodialysis patients - an 18-week, open-label trial

Annual influenza vaccination is recommended, but its efficacy in dialysis population is still controversial. Here we aimed to compare the dynamic changes of immune response between various influenza vaccination protocols in hemodialysis patients. A 18-week open label, non-randomized, controlled trial was conducted during 2011–2012. The efficacy between unvaccinated, one- and two-dose regimens were evaluated in 175 hemodialysis patients. Immunogenic profiles were assessed by hemagglutination-inhibition assays. At 3–9 weeks post-vaccination, antibody responses were similar between the one- and two-dose regimens, while the seroprotection rates (antibody titer ≥1:40) for influenza A were 55.6–82.5% in the adult (18–60 years) and 33.3–66.7% in the elderly (>60 years). Meanwhile, the seroprotection rates for influenza B were low (4.0–25.0%). By 18 weeks post-vaccination, the seroprotection rates for influenza A and B declined (0.0–33.3%) in both the adult and elderly receiving one- or two-dose regimens. Of dialysis patients, at most 2.4% developed moderate to severe adverse effects(myalgia and headache) after vaccination. In conclusion, the two-dose regimen could not improve immune responses than the one-dose regimen in hemodialysis patients; meanwhile the induced protective antibodies of both regimens could not be maintained for more than 4 months. Modification of current influenza vaccination strategy in dialysis population should be re-considered.

Preemptive kidney transplantation--a team experience in Uruguay

Kidney transplantation is the best treatment for end-stage chronic renal disease. In Uruguay, the prevalence of patients on dialysis is 757 patients per millon inhabitants, plus 316 alive with a functioning renal graft. We install a preemptive renal transplantation program. Twenty-five patients received grafts without dialysis from 2004 to 2013, 5 receiving their 2nd transplantation and 17 from cadaveric donors, with 7.4 ± 7.7 months in the waiting list. At 24 months, patients' survival rate was 100% and the grafts' 97%, with a serum creatinine of 1.4 ± 0.6 mg%. The developed programs of dialysis and renal health care contributed install our preemptive kidney transplantation. Kidney transplantation should be proposed to selected patients with chronic renal failure as primary therapy of substitution of renal function.

Lupus flares in two established end-stage renal disease patients with on-line hemodiafiltration during pregnancy - case series

Many patients with established end-stage renal disease on maintenance dialysis as a result of lupus nephritis are young females in their reproductive years. We report two such patients dialyzed with on-line hemodiafiltration who developed reactivation of lupus disease activity only when they conceived after initial systemic lupus erythematosus burnout. We believe that the flare was triggered by both efficient dialysis and hormonal changes during pregnancy. The flares were treated with oral corticosteroids with an excellent response. Both patients had live births but delivered preterm.

Comparison of preemptive kidney transplant recipients with nonpreemptive kidney recipients in single center: 5 years of follow-up

BACKGROUND

For suitable patients with end-stage renal disease, kidney transplantation (KT) is the best renal replacement therapy, resulting in lower morbidity and mortality rates and improved quality of life. Preemptive kidney transplantation (PKT) is defined as transplantation performed before initiation of maintenance dialysis and reported to be associated with superior outcomes of graft and patient survival. In our study, we aimed to compare the 5-year outcomes of PKT and nonpreemptive kidney transplantation (NPKT) patients who received KT in our center, to define the differences according to complications, comorbidities, adverse effects, clinical symptoms, periodical laboratory parameters, rejection episodes, graft, and patient survival.

METHODS

One hundred kidney transplantation (37 PKT, 63 NPKT) recipients were included in our study. All patients were evaluated for adverse effects, complications, comorbidities, clinical symptoms, monthly laboratory parameters, acute rejection episodes, graft, and patient survival.

RESULTS

Acute rejection episodes were found to be significantly correlated with graft loss in both groups (P = 0.02 and P = 0.01, respectively). Hypertension after transplantation was diagnosed by ambulatory blood pressure measurement in 74 of 100 patients. Twenty-five of 37 (67.6%) of Group 1 (PKT) recipients had hypertension while 54 of 63 (85.4%) of Group 2 (NPKT) had hypertension. The incidence of hypertension between two groups was statistically significant (P = 0.03), but this finding was not correlated to graft survival (P = 0.07). Some patients had serious infections, requiring hospitalization, and were treated immediately. Infection rates between the two groups were 10.8% for Group 1 patients and 31.7% for Group 2 patients and were statistically significant (P = 0.02). Infection, requiring hospitalization, was found to be statistically correlated to graft loss in only NPKT patients (P = 0.00).

CONCLUSION

While the comparison of PKT and graft and patient survival with NPKT is poorer than we expected, lower morbidity rates of hypertension and infection are similar with recent data. Avoidance of dialysis-associated comorbidities, diminished immune response, and cardiovascular complications are the main benefits of PKT.

A specific immune transcriptomic profile discriminates chronic kidney disease patients in predialysis from hemodialyzed patients

BACKGROUND

Chronic kidney disease (CKD) patients present a complex interaction between the innate and adaptive immune systems, in which immune activation (hypercytokinemia and acute-phase response) and immune suppression (impairment of response to infections and poor development of adaptive immunity) coexist. In this setting, circulating uremic toxins and microinflammation play a critical role. This condition, already present in the last stages of renal damage, seems to be enhanced by the contact of blood with bioincompatible extracorporeal hemodialysis (HD) devices. However, although largely described, the cellular machinery associated to the CKD- and HD-related immune-dysfunction is still poorly defined. Understanding the mechanisms behind this important complication may generate a perspective for improving patients outcome.

METHODS

To better recognize the biological bases of the CKD-related immune dysfunction and to identify differences between CKD patients in conservative (CKD) from those in HD treatment, we used an high-throughput strategy (microarray) combined with classical bio-molecular approaches.

RESULTS

Immune transcriptomic screening of peripheral blood mononuclear cells (1030 gene probe sets selected by Gene-Ontology) showed that 275 gene probe sets (corresponding to 213 genes) discriminated 9 CKD patients stage III-IV (mean±SD of eGFR: 32.27+/-14.7 ml/min) from 17 HD patients (p<0.0001, FDR=5%). Seventy-one genes were up- and 142 down-regulated in HD patients. Functional analysis revealed, then, close biological links among the selected genes with a pivotal role of PTX3, IL-15 (up-regulated in HD) and HLA-G (down-regulated in HD). ELISA, performed on an independent testing-group [11 CKD stage III-IV (mean±SD of eGFR: 30.26±14.89 ml/min) and 13 HD] confirmed that HLA-G, a protein with inhibition effects on several immunological cell lines including natural killers (NK), was down-expressed in HD (p=0.04). Additionally, in the testing-group, protein levels of CX3CR1, an highly selective chemokine receptor and surface marker for cytotoxic effector lymphocytes, resulted higher expressed in HD compared to CKD (p<0.01).

CONCLUSION

Taken together our results show, for the first time, that HD patients present a different immune-pattern compared to the un-dialyzed CKD patients. Among the selected genes, some of them encode for important biological elements involved in proliferation/activation of cytotoxic effector lymphocytes and in the immune-inflammatory cellular machinery. Additionally, this study reveals new potential diagnostic bio-markers and therapeutic targets.

Acute kidney injury: effect of hemodialysis membrane on Hgf and recovery of renal function

OBJECTIVES

Acute kidney injury (AKI) is associated with a high mortality and morbidity rate. In this study we investigated whether dialysis membranes influence the recovery of renal function, through the regulation of hepatocyte growth factor (HGF).

DESIGN AND METHODS

21 patients were enrolled and assigned to hemodialysis (HD) with cellulose (CE, N=11) versus polymethylacrylate (PMMA, N=10) membranes in alternating order. HGF and IL-1 were measured in serum and in peripheral blood mononuclear cells (PBMC) supernatants collected immediately before the first HD session (T0), at 15 minutes (T15), at 240 minutes (T240) and after the last HD, when renal recovery occurred. Eight healthy volunteers were the controls (CON).

RESULTS

Time to renal function recovery was lower in CE than in PMMA patients. Serum HGF in HD patients was significantly higher than in CON. HGF levels were higher in CE than in PMMA patients at T15 (13.4±2.7 vs 8.9±3.0 ng/mL, P=0.004) and T240. At recovery, HGF levels decreased. IL-1 serum levels showed a similar trend (at T15 CE: 20.5±2.9 vs PMMA: 16.9±3.2 pg/mL, P=0.005). HGF release significantly increased in the course of HD, resulting in higher levels in CE than that in PMMA patients. Considering all the patients, basal HGF release negatively correlated with time to renal recovery (r2=0.42, P<0.01).

CONCLUSIONS

Here we demonstrated that dialysis membranes influence the cytokine profile in AKI patients, HGF release being higher in patients treated with the CE membrane, in comparison to PMMA. Our results suggest that treatment with CE might improve clinical outcomes, possibly through increased release of HGF.

Alloantigen-stimulated induction and release of CD30 in patients with end-stage renal failure

High serum levels of soluble CD30 (sCD30) are associated with poor renal allograft survival, and regulatory T cells (Tregs) influence allograft survival depending on CD30 signaling. However, how sCD30 modulates alloimmune responses remains poorly understood. We measured the level of Tregs and sCD30 in patients with end-stage renal failure (ESRF) and analyzed whether allo- or polyclonal stimulation of the patients' T cells results in the expression and release of CD30. ESRF patients showed increased serum sCD30 levels and lower percentages of circulating Tregs as compared to healthy controls (HC) (p<0.001 and 0.024). Polyclonal and allogeneic stimulation resulted in higher expression of CD30, and after polyclonal stimulation, ESRF patients showed higher percentages of CD30-expressing T cells than HC (p<0.001). Compared to autologous stimulation, allogeneic stimulation induced significantly higher expression of CD30 on T cells of ESRF patients only. After polyclonal as well as allogeneic stimulation, an increased sCD30 content was found in culture supernatants of both ESRF patients and HC (p<0.001). Together with decreased Tregs, high serum sCD30 and increased induction of CD30 on T cells after polyclonal stimulation may explain exacerbated alloimmune responses and poor allograft survival in ESRF patients in whom immunosuppression is not able to control the alloimmune response.

Increased oxidative stress in foam cells obtained from hemodialysis patients

Premature atherosclerosis represents the main cause of mortality among end-stage renal disease patients (ESRD). Increased inflammation and oxidative stress are involved in initiation and progression of the atherosclerotic plaque. As foam cells are capable of producing significant amounts of inflammatory mediators and free radicals, we hypothesized that foam cells from uremic patients could produce more inflammation and oxidative stress than foam cells from normal people and be, somehow, involved in the accelerated atherosclerosis of uremia. To test this hypothesis, the levels of a few markers of inflammation and oxidative stress: Tumor necrosis factor-α, inducible nitric oxide synthase, malondialdehyde, nitric oxide by-products were measured in the supernatants of macrophage-derived foam cells cultures from 18 hemodialysis patients and 18 apparently healthy individuals controls. Malondialdehyde levels in the supernatant of cell cultures (macrophages stimulated or not with native and oxidized lipoprotein) were significantly increased in uremic patients; no statistically significant difference was found between the supernatant concentrations of nitric oxide by-products, inducible nitric oxide synthase activity, and tumor necrosis factor-α between patients and controls. Our results, obtained with human macrophages and macrophage-derived foam cells, are compatible with the theory that increased cellular oxidative stress and inflammatory activity in ESRD patients could accelerate the atherosclerotic process. The present culture protocol showed it is possible to use human mononuclear cells to evaluate the oxidative metabolism of foam cells, which are considered to be the initial step of atherosclerotic lesions.

Oxidized LDL to autoantibodies against oxLDL ratio - the new biomarker associated with carotid atherosclerosis and cardiovascular complications in dialyzed patients

OBJECTIVE

To investigate the role of autoantibodies against oxidized LDL (oxLDL-Ab) in clearing of oxLDL from circulation in dialyzed uremic patients, as well as the significance of this process in the carotid atherosclerosis and cardiovascular complications.

METHODS

oxLDL, oxLDL-Ab and intima-media thickness (IMT) were measured in 132 uremic patients on hemodialysis (HD), peritoneal dialysis (PD) or conservative treatment both with and without cardiovascular disease (CVD) and in 29 healthy controls. The ratio of oxLDL to oxLDL-Ab (oxLDL/oxLDL-Ab), reflecting the balance between in vivo oxidative LDL modification and the clearance of oxLDL from circulation was also calculated.

RESULTS

oxLDL were lower, whereas oxLDL-Ab were higher in patients without CVD compared to those with CVD. oxLDL/oxLDL-Ab ratio was also significantly lower in dialyzed subjects without CVD compared to their counterparts with CVD and healthy controls. IMT values were significantly higher in uremic patients compared with controls, and patients with CVD had particularly elevated IMT compared with those without CVD. The inverse correlation was between IMT and oxLDL-Ab, whereas the IMT was strongly and positively associated with oxLDL/oxLDL-Ab ratio. There was the weak inverse relationship between oxLDL and oxLDL-Ab levels in dialyzed patients. Multiple stepwise regression analysis identified oxLDL/oxLDL-Ab ratio as one of the predictors of IMT in the whole dialyzed group.

CONCLUSIONS

oxLDL/oxLDL-Ab ratio could be a new biomarker significantly and independently associated with carotid atherosclerosis in dialyzed patients. A titer of oxLDL-Ab and oxLDL/oxLDL-Ab ratio seem to play an important role for distinguishing patients with and without cardiovascular complications.

The kidney-first initiative: what is the current status of preemptive transplantation?

Preemptive kidney transplant (PKT)-defined as transplant before dialysis-has numerous advantages as a treatment approach for patients with advanced renal disease. In the past 15 years, PKT has become more common and has been performed at higher levels of estimated glomerular filtration rate, particularly among recipients of live-donor transplants, among whom timing of transplantation is easier to control. However, recent studies have raised important new concerns about unintended consequences of early versus late PKT. In this article, we review the convincing evidence that PKT offers diverse advantages for patients, discuss potential problems that might emerge from PKT at higher levels of renal function, examine the feasibility of a "just-in-time" PKT strategy for transplant centers, and discuss whether a new kidney allocation system could affect rates of PKT.

Paradoxical cryptococcal immune reconstitution inflammatory syndrome in advanced chronic kidney disease

Cryptococcal-related immune reconstitution inflammatory syndrome (IRIS) is frequently seen in immunocompromised patients. A 45-year-old man with advanced chronic kidney disease (CKD) received intensive antifungal treatment for pulmonary cryptococcosis. Despite negative pleural effusion cultures and declining serum cryptococcal antigen titers, the patient presented with progressive pulmonary infiltration, intermittent fever, and elevated C-reactive protein. Steroids were given for suspected IRIS, and the clinical condition improved dramatically. This is the first report on paradoxical cryptococcal IRIS in a patient with advanced CKD.

Preemptive deceased-donor renal transplant in adults: single-center experience and outcome

OBJECTIVES

Preemptive renal transplant has been associated with better survival of both the allograft and the recipient than has conventional renal transplant. It remains unclear, however, whether preemptive transplant is optimal for renal replacement therapy. We describe our experience with preemptive renal transplant.

MATERIALS AND METHODS

We retrospectively analyzed 32 preemptive and 132 nonpreemptive deceased-donor renal transplants performed in our center between January 2006 and January 2008.

RESULTS

The mean follow-up was 47.44 ± 11.92 months in the preemptive group, compared with 47.49 ± 14.87 months in the nonpreemptive group. The 1-, 3-, and 5-year patient survival rates were 93.8%, 90.6%, and 90.6% in the preemptive group, and 92.4%, 90.9%, and 87.6% in the nonpreemptive group; and the 1-, 3-, and 5-year graft survival rates were 93.8%, 93.8%, and 93.8% in the preemptive, and 89.4%, 85.6%, and 73.8% in the nonpreemptive group. None of these differences was statistically significant. Rates of acute rejection (P = .04) and delayed graft function (P = .03) were significantly lower in the preemptive group. The mean plasma creatinine levels at 1 day before transplant and at 1 and 12 months after transplant were 715.16 ± 114.92 μmol/L, 113.15 ± 29.17 μmol/L, and 94.59 ± 18.56 μmol/L in the preemptive group, and 772.62 ± 111.38 μmol/L, 118.46 ± 30.94 μmol/L, and 100.78 ± 15.03 μmol/L in the nonpreemptive group. None of these differences was statistically significant.

CONCLUSIONS

Preemptive transplant can yield outcomes comparable to those of renal transplant after dialysis, and result in better quality of life for patients with end-stage renal disease, as well as reduced cost. Preemptive transplant is a better choice for renal replacement therapy, if possible.

Increased interleukin-17 producing effector memory T cells in the end-stage renal disease patients

Patients with end-stage renal disease (ESRD) exhibit immune dysregulation, but the precise immunological profile and the effect of hemodialysis (HD) on it has not been investigated fully. Thirty-eight ESRD patients (22 on HD and 16 in pre-dialysis) and 24 healthy volunteers were included. We compared the T cell immune profiles as in these patients. Among the effector T cell subset, the percentages of Th17 and Th2 cells were significantly higher in the ESRD group than in the healthy controls (P<0.05). The percentage of Th1 cells did not differ significantly between these groups. The percentages of Th1, Th2 and Th17 cells did not differ significantly (P>0.05) between the two subgroups within the ESRD group. The CCR4(-)CCR6(+)/CD4(+) T cell percentage was also significantly higher in the ESRD group. The naïve T cell (T(naïve)) percentage was significantly lower in the ESRD group, and the difference between patients and controls was greater in the pre-dialysis patients than in the HD patients (P<0.05, for each comparison). By contrast, the percentages of central memory T cells (T(CM)) and effector memory T (T(EM)) cells were significantly higher in the ESRD group. Interleukin-17 production by T(EM) cells was significantly higher in the ESRD group. The severity of uremia was related negatively to the T(naïve) cell percentage but positively to the T(CM) and T(EM) cell percentages. The percentages of T(EM) and CD45RA(+) T effector memory subsets of CD8(+) T cells were significantly higher in the ESRD group (P<0.05). The result of this study showed significantly altered T cell-associated immunity and that it could not be corrected with hemodialysis.

Bio-incompatibility and Th2 polarization during regular dialysis treatment

Long-term hemodialysis treatment results in chronic monocyte activation with cytokine release. It generates Treg induction with potential immune dysfunction and associated clinical complications. Recent immunological data and preliminary clinical evidence suggest that synthetic polymers and vitamin E coated membranes are associated with a significant improvement in hemodialysis tolerance when compared to cellulose membranes. The aim of this review is to update cytokine release, T-cell polarization, and its clinical impact in patients under extracorporeal hemodialysis comparing traditional cellulose to synthetic/vitamin E coated membranes.

Clinical outcome of preemptive kidney transplantation in patients with diabetes mellitus

End-stage renal disease (ESRD) caused by diabetic nephropathy is increasing throughout the world. The survival of diabetic patients treated by transplantation has improved nowadays. Although recent studies have demonstrated preemptive kidney transplantation to be associated with better graft survival in CKD patients, the effect of pre-transplantation dialysis on graft outcomes among diabetic ESRD patients is unclear. This analysis summarized our experience with preemptive kidney transplantation in diabetic ESRD patients by retrospectively comparing 70 such patients transplanted between 1995 and 2009. These 70 patients were divided into two groups: 30 patients underwent preemptive and the other 40 transplantation after maintenance hemodialysis or peritoneal dialysis. We compared graft survivals, acute rejection episodes, postoperative complications, and delayed graft function rates. The 10-year patient survival of 100% in the preemptive group was similar to that of the nonpreemptive group (85%, P = .11). But the 10 year graft survival was higher among the preemptive than the nonpreemptive group (100% vs 75%, P = .02). Pre-transplantation modality did not affect graft survival. Therefore, preemptive kidney transplantation should be applied to eligible patients with diabetic ESRD.

Indications for and barriers to preemptive kidney transplantation: a review

Preemptive kidney transplantation is the treatment of choice for end-stage renal disease. Compared with nonpreemptive transplantation, preemptive transplantation is significantly associated with improved kidney allograft survival in recipients of either cadaver or living-donor transplants. This seems to be related to better patient survival. It can be proposed to all patients, but still needs to be evaluated for repeat transplantation. The main barriers are organ-allocation policies and late referral of patients to transplantation centers.

Comparison of parameters of chronic kidney disease following paediatric preemptive versus non-preemptive renal transplantation

PRT is the preferred modality for renal replacement therapy in children. Despite this, there are no studies CKD parameters as per K/DOQI criteria between PRT and NPRT in children. This was a single-centre cross-sectional study of RTR with at least one yr of post-transplant follow-up. CKD parameters as per K/DOQI were compared between PRT and NPRT. Thirty percent (39/129) of our study population was PRT. Despite similar baseline characteristics at the time of transplantation and similar post-transplantation follow-up period, a significantly lower proportion of PRT (1, 2%) were in Stage 4 CKD in contrast to NPRT (14, 16%); p = 0.03. This was also reflected in better CKD parameters among PRT with significantly lower incidences of hypertension and acidosis (p = 0.02). CKD medications were also more commonly prescribed in NPRT (p = 0.002). We demonstrated improved CKD parameters and lower use of CKD medications among PRT when compared with NPRT. This finding should act as an added impetus for PRT programmes.

Hepatitis C virus screening and clinical monitoring of biomarkers in patients undergoing hemodialysis

In this study, 395 volunteers were enrolled to investigate the seroprevalence of hepatitis C virus, the immunological and the alanine aminotransferase (ALT) biomarkers amongst hemodialysis patients, living in Manaus, Brazil. An overall seroprevalence of 13.9% was found in the hemodialysis patients. Analysis of seroconversion patterns demonstrated that most patients with HCV seroconverted up to 10 years following the first hemodialysis session. Anti-NS5 antibody was detectable in 60.4% of patients with HCV. A lower percentage of circulating CD3(+) and CD4(+) T-cells was found in patients seronegative for HCV, whereas a higher frequency of CD8(+) T-cells was the hallmark of patients with HCV. An overall low activation state of monocytes and eosinophils were observed in hemodialysis patients. In contrast, a higher frequency of activated neutrophils was observed in patients with HCV, selectively in the NS5+ subgroup. All hemodialysis patients had a higher percentage of activated lymphocytes, with the higher activation state in patients with NS5- reactivity. Higher ALT levels were observed in patients with HCV, especially in the NS5+ subgroup. Interestingly, the ALT levels were correlated negatively with the lymphocyte activation state, selectively in the NS5- subgroup, suggesting a protective role of these activated lymphocytes in patients with HCV. These findings reinforce the importance of the transmission of HCV among hemodialysis patients, suggesting that apart from the HCV screening, the serological and ALT biomarkers may represent important predictors of morbidity and/or mortality among patients undergoing hemodialysis.

Preemptive transplantation and long-term outcome in living donor kidney transplantation, single-center experience

Although preemptive transplantation of kidneys from living donors without the previous initiation of dialysis is associated with longer allograft survival in a USRDS cohort, the effect of pretransplantation dialysis on graft outcome is still controversial in Korea. The purpose of this study was to evaluate the differential effects on long-term outcomes of living donor kidney transplantation according to initiation of dialysis and its duration or no dialysis. We performed a retrospective cohort study of 494 patients who received a first kidney transplant from a living donor between 1990 and 2006. The mean duration for dialysis was 14.5+/-22.2 months. The 10-year patient survival of 98.0% in the preemptive group was not significantly higher than the dialysis group (91.2%, P>.05). However, 10-year graft survival was higher in the preemptive than the dialysis group (preemptive 94.4%, dialysis 76.5%; P<.05). The differential effect of pretransplant dialysis either by hemodialysis or peritoneal dialysis was not significant, although peritoneal dialysis as a pretransplant treatment seemed to be beneficial on long-term graft survival (5-year graft survival; peritoneal 94.8% and hemodialysis 89.2%). The duration of dialysis did not affect graft survival in our study cohort. In conclusion, we suggest that preemptive transplantation should be applied to eligible patients.

Preemptive kidney transplantation in patients with diabetes mellitus

Kidney transplantation is the most preferred treatment for end-stage renal disease because it improves not only the patient's survival compared with dialysis, but also the quality of life. Preemptive transplantation is transplantation performed prior to the initiation of renal dialysis. Recent observational studies have shown increased patient and graft survival with preemptive transplantation, compared to patients receiving transplantation after the initiation of dialysis. Preemptive simultaneous pancreas and kidney transplantation in type 1 diabetic recipients has also been shown to improve patient survival. These results indicate the importance of early referral of patients who have chronic kidney disease to nephrologists and transplant centers.

Disturbances of acquired immunity in hemodialysis patients

Acquired immunity disturbances in hemodialysis (HD) patients are many and diverse. They are caused by uremia per se, the HD procedure, chronic renal failure complications, and therapeutic interventions for their treatment. Current data suggest that acquired immunity disturbances in HD patients concern mainly the T-lymphocyte and the antigen-presenting cell (APC). The T-lymphocyte-dependent immune response is deficient, predisposing to infections and inadequate response to vaccinations. In addition, APCs are preactivated, which seems to be responsible for the malnutrition-inflammation-atherosclerosis syndrome, and also affects T-lymphocyte function. At the molecular level it is assumed that the interaction between the APC and the T-lymphocyte is impaired. This disturbance is likely to concern the signal that results from the interaction between the major histocompatibility complex:peptide complex on APC surfaces and T-cell receptors on T-lymphocyte surfaces, or the signal that results from the interaction among the co-receptors of these two cells. The aim of the present review was to collect and classify the available clinical and experimental data in this area. Although many pieces are still missing from the puzzle, a better understanding of the responsible molecular mechanisms, will potentially lead to increased survival and a better quality of life in HD patients.

A review of critical periods for opportunistic infection in the new transplantation era

BACKGROUND

The risk of opportunistic infection (OI) is considered to be maximum during the first six months after solid organ transplantation. The aim of this study was to know the incidence and risk factors for OI in the late period (>6 months) compared with the early period (<6 months) after solid organ transplantation.

METHODS

We used the online database of the Spanish Network of Infection in Transplantation (RESITRA), which prospectively analyzed 2,702 solid organ transplantation recipients from August 2003 to February 2005. Univariate and multivariate analyses were performed to calculate the risk factors associated with the development of late OI.

RESULTS

A total of 131 patients (6%) developed 176 infectious episodes in the late period. Although the incidence of infection and cytomegalovirus disease (0.4 per 1000 transplant days and 0.05 per 1000 transplant days, respectively) was lower than in the early period (3.5 per 1000 transplant days and 0.8 per 1000 transplant days; P<0.0001), the incidence of other OIs was similar in both periods (0.05 per 1000 transplant days versus 0.03 per 1000 transplant-days, P=0.5). Patients with the higher risk for developing late OI were those receiving early cytomegalovirus prophylaxis, patients who developed two or more episodes of acute rejection during the early period, patients with recurrent bacterial infection during the early period, patients with renal failure requiring dialysis, and patients with chronic graft malfunction.

CONCLUSIONS

Our data suggest that in some high-risk patients, the critical period of risk for OI must be expanded beyond the first six months after transplant.

Naïve and central memory T-cell lymphopenia in end-stage renal disease

End-stage renal disease (ESRD) is associated with increased propensity to infections, diminished response to vaccination, impaired cell-mediated immunity, and reduced CD4+/CD8+ T-lymphocyte ratio. Four subsets of CD4+ and CD8+ T cells have been recently identified: naïve cells (as yet uncommitted), central memory (CM) cells (previously programmed), and CD45RA-positive and CD45RA-negative effector memory (EM) cells (programmed to perform specific effector functions). The effect of ESRD on subpopulations of T lymphocytes is unclear and was studied here. Twenty-one hemodialysis patients and 21 age-matched controls were studied. Pre- and post-dialysis blood samples were obtained and analyzed by three-color flow cytometry. CD4+/CD8+ ratio and the numbers of the naïve and CM CD4+ and CD8+ T cells were significantly reduced, whereas the numbers of EM CD4+ and CD8+ T cells were unchanged in the ESRD group. The reduction of the naïve and CM T-cell counts in the ESRD group was associated with increased apoptosis of these cells. Negative correlations were found between severity of azotemia, oxidative stress, and hyperphosphatemia with the number of naïve T cells. Comparison of diabetic with non-diabetic ESRD patients revealed higher numbers of total CD8+ cells and EM CD8+ T cells in the diabetic group. Dialysis did not significantly change the naïve and CM CD4+ or CD8+ cell counts, but significantly lowered CD8+ EM cell count. Thus, ESRD results in increased apoptosis and diminished populations of naïve and CM T lymphocytes. This phenomenon may, in part, contribute to the impaired immune response in this population.

Risk factors for invasive aspergillosis in solid-organ transplant recipients: a case-control study

BACKGROUND

To facilitate the design of strategies for prevention of invasive aspergillosis in solid-organ transplant recipients, this study investigates whether the development of early-onset and late-onset aspergillosis are related to different risk factors, thereby distinguishing 2 risk populations for this serious complication.

METHODS

A retrospective case-control study was performed, including 156 cases of proven or probable invasive aspergillosis in patients recruited from 11 Spanish centers since the start of the centers' transplantation programs.

RESULTS

Among all patients, 57% had early-onset IA (i.e., occurred during the first 3 months after transplantation). Risk factor analysis in this group identified as significantly associated risk factors a more complicated postoperative period, repeated bacterial infections or cytomegalovirus disease, and renal failure or the need for dialysis. Among patients with late-onset infections (i.e., occurred > 3 months after transplantation), who comprised 43% of cases, the patients at risk were older, were in an overimmunosuppressed state because of chronic transplant rejection or allograft dysfunction, and had posttransplantation renal failure.

CONCLUSIONS

Risk factors in patients with early-onset cases and patients with late-onset cases of posttransplantation invasive aspergillosis are not the same, a fact that could have implications for the preventive approaches used for this infection.

Impact of simultaneous kidney-pancreas transplant and timing of transplant on kidney allograft survival

Since 1988 over 10 000 simultaneous cadaveric pancreas-kidney transplants (SPK) have been performed in the United States among patients with end-stage renal disease due to Type 1 diabetes (T1DM). The two aims of this study were to assess the impact on kidney allograft survival of (i) SPK versus transplantation of a kidney alone (KA), and (ii) SPK prior to versus after initiation of chronic dialysis. This retrospective, non-concurrent cohort study examined registry data collected from 8323 patients waitlisted in the United States for an SPK and transplanted with either an SPK or a KA during January 1, 1990 - October 31, 2002. SPK recipients had an adjusted hazard ratio for kidney allograft loss of 0.63 (95% CI: 0.51-0.77, p < 0.001) compared to transplantation without pancreas allograft. SPK recipients who received their allografts prior to beginning chronic dialysis had a lower rate of kidney allograft loss than SPK recipients who received their transplant after initiation of chronic dialysis (adjusted hazard rates (HR) = 0.83, 95% CI: 0.69-0.99, p = 0.042). Simultaneous transplantation of pancreas-kidney compared to kidney transplantation alone and SPK prior to the initiation of chronic dialysis compared to SPK after initiation of dialysis were both associated with longer kidney allograft survival.

The imbalance in the ratio of Th1 and Th2 helper lymphocytes in uraemia is mediated by an increased apoptosis of Th1 subset

BACKGROUND

In uraemia there is a reduction in the total number of T lymphocytes and an imbalance in the ratio of Th1/Th2 T-helper (Th) lymphocytes. A higher rate of apoptosis in T lymphocytes has been reported in haemodialysis patients. The aims of the present study were to assess the Th1/Th2 pattern in uraemia and to evaluate whether a relative increase in Th1 apoptosis may explain the Th1/Th2 imbalance observed in uraemic patients.

METHODS

Seventeen non-dialysed uraemic patients were evaluated; eight healthy volunteers served as controls. Intracellular interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) were measured by direct intracellular immunofluorescence and flow cytometry. Apoptosis was determined by flow cytometry using annexin V or TUNEL. Mechanisms of apoptosis were assessed by determination of Fas and Bcl-2 expression.

RESULTS

Cell production of cytokines is significantly higher in uraemic patients than in controls. In addition, in uraemic patients only 5.1+/-2.1% of the T lymphocytes contained IFN-gamma (Th1 cells) while 61.9 +/- 14.8% contained IL-4 (Th2 cells) (P < 0.0001). The percentage of apoptosis was 29.6 +/- 6.3% and 4.7 +/- 1.6% in Th1 and Th2 lymphocytes, respectively (P < 0.001). Fas expression was higher in Th1 than in Th2 cells and the expression of Bcl-2 was lower in Th1 than in Th2 cells. The apoptosis induced by anti-Fas antibodies was similar in both types of lymphocytes.

CONCLUSIONS

In uraemia there is a reduction in the proportion of Th1 lymphocytes due to a higher rate of apoptosis in this subset of lymphocytes. Th1 from uraemic patients show a higher expression of Fas and a lower expression of Bcl-2 than Th2. This makes uraemic Th1 cells more susceptible to apoptosis. The Th1/Th2 imbalance may contribute to alterations in cellular immunity observed in chronic kidney disease patients.

[Association of humans leucocitary antigens with humoral nonresponsive to hepatitis B vaccine in chronic hemodialysis patients]

Vaccination using surface antigen from hepatitis B virus has not been successfully responded by hemodialysis patients. The present study was aimed at assessing a possible relationship between human leukocyte antigens and the low production of protective antibodies (anti-HbS) against the surface antigen from hepatitis B by patients with chronic renal failure submitted to hemodialysis programs. The antigens HLA-DR and HLA-DQ were identified in 76 hemodialysis patients through classic microlymphotoxicity. Our results showed that 34.2% of the patients were non-responsive to the vaccine VHB. The most frequent HLA specificity were: HLA-DR3, DR-7 and DQ2 with a significant association for HLA-DR3 (p=0.0025; OR 5.1; IC 95% 1.36-19.10). Such data suggest an association between genes from HLA class II antigens and the humoral non-response to the vaccine VHB.

Preemptive renal transplantation: why not?

Dialysis has been the long-established initial choice of treatment for persons with end-stage renal disease. Transplantation before dialysis, or preemptive renal transplantation (PRT), has been controversial because of the paucity of clinical evidence that has clarified the benefits vs. risks of this approach. However, several recent observational analyses indicate that PRT is the optimal strategy to benefit patients requiring renal replacement therapy. This current review will discuss the advantages that are associated with PRT, and will summarize studies that have investigated the impact of the timing of transplantation on outcomes. We will also discuss the utility of PRT from various perspectives, and describe the challenges ahead in expanding the opportunity of PRT for more patients.

Acute ischemia/reperfusion injury after isogeneic kidney transplantation is mitigated in a rat model of chronic renal failure

The influence of chronic renal failure on renal susceptibility to an acute ischemic insult was evaluated. Recipient Lewis rats were randomly assigned to undergo 5/6 nephrectomy (chronic renal failure, CRF) or sham operation (normal renal function, NRF). After 11 weeks, normal kidneys of Lewis donor rats were transplanted in the recipients. The outcome of the isografts was assessed. Filtration capacity of the isografts in the CRF rats was preserved to approximately one-quarter of its normal capacity on the 1st day post-transplantation, whereas it fell to 0 in the NRF rats. This was reflected by a significantly higher increase in serum creatinine in the latter group. The isografts in the CRF rats had a significantly lower degree of acute tubular necrosis and no increase in the number of macrophages and T lymphocytes in the first 24 h in contrast to the NRF rats. Epithelial regeneration and repair started earlier in the CRF group. In conclusion, the present study indicated that CRF blunted ischemia/reperfusion injury of a transplanted kidney, and that its regeneration capacity was certainly not hampered by the presence of chronic uremia. These results will be the basis for studies on modulation of early leukocyte-endothelial interactions resulting from immunological disturbances inherent to the uremic environment.

Mortality, malnutrition, and atherosclerosis in ESRD: what is the role of interleukin-6?

There is growing evidence that increased plasma concentrations of CRP strongly predict cardiovascular death in both non-renal and renal patient populations. The interleukin-6 (IL-6) system activity, which is the major mediator of the acute phase response, is often markedly up-regulated in uremic patients and has also been shown to predict outcome. This raises the issue of whether or not IL-6 per se may contribute to increased mortality from malnutrition and atherosclerotic cardiovascular disease in uremic patients. The causes of elevated IL-6 levels in the uremic circulation are not fully understood, although a number of factors prevalent in uremic patients, such as hypertension, adiposity, infections, and chronic heart failure may all contribute. However, factors associated with the dialysis procedure, such as bioincompatibility and non-sterile dialysate, may stimulate IL-6 production. Furthermore, available evidence suggests that genetic factors may also have an impact on circulating plasma IL-6 levels. We advance the hypothesis that IL-6 may play a central role in the genesis of inflammatory-driven malnutrition and that it may be regarded as a significant proatherogenic cytokine. This hypothesis may provide a rationale to test if targeted anti-cytokine therapy may be one way to combat the unacceptable high cardiovascular mortality rate among dialysis patients.

Effect of the use or nonuse of long-term dialysis on the subsequent survival of renal transplants from living donors

BACKGROUND

The effect on allograft survival of the transplantation of kidneys from living donors without the previous initiation of long-term dialysis is controversial.

METHODS

Using data from the U.S. Renal Data System, we performed a retrospective cohort study of 8481 patients who were or who were not treated by long-term dialysis before receiving a kidney transplant from a living donor. The relative rate of allograft failure for patients who received a transplant without previously undergoing long-term dialysis, as compared with patients who underwent long-term dialysis before transplantation, was assessed by proportional-hazards analysis, with adjustment for potential confounding variables, including the transplantation center and median household income. The association between the receipt of a kidney transplant from a living donor without previous dialysis ("preemptive transplantation") and the risk of biopsy-confirmed acute rejection within six months after transplantation was evaluated by conditional logistic-regression analysis, with adjustment for the transplantation center.

RESULTS

Transplantation of a kidney from a living donor without previous long-term dialysis was associated with a 52 percent reduction in the risk of allograft failure during the first year after transplantation (rate ratio, 0.48; P=0.002), an 82 percent reduction during the second year (rate ratio, 0.18; P=0.001), and an 86 percent reduction during subsequent years (rate ratio, 0.14; P=0.001), as compared with transplantation after dialysis. The reduction in the rate of allograft failure during the first year was attenuated when adjustment was made for the timing of acute rejection within the first year (rate ratio, 0.69; 95 percent confidence interval, 0.44 to 1.10; P=0.10). Increasing duration of dialysis was associated with increasing odds of rejection within six months after transplantation (P=0.001).

CONCLUSIONS

Preemptive transplantation of kidneys from living donors without the previous initiation of dialysis is associated with longer allograft survival than transplantation performed after the initiation of dialysis.

Molecular aspects of T- and B-cell function in uremia

Chronic renal failure is associated with severe alterations of the immune system. Infections are responsible for a large part of the mortality in hemodialysis patients, and vaccination is mostly ineffective. Global tests of the immune function show greatly diminished activation of T cells. However, the intrinsic function of T and B cells is normal when they are provided with normal signaling from antigen-presenting cells (APCs). Patients with chronic renal failure show a defective function of costimulation derived from APCs leading to impaired activation of effector lymphocytes. Two major components of immune deviation are relevant: reduced signaling caused by impaired expression of the costimulatory molecule B7-2 (CD86) on monocytes leads to low activation of helper T cells. This dysfunction is associated with uremia and may be improved by high-efficiency renal replacement therapy. The other component is inflammatory activation of APCs mainly due to the hemodialysis procedure. Inflammation, characterized by overproduction of cytokines such as interleukin-1beta (IL-1beta) or IL-6, correlates with low effector activation. Furthermore, inflammatory cytokines such as IL-12 deviate the functional pattern of T-cell activation toward Th1 differentiation, thus leading to an additional reduction of Th2- and B-cell function. The individual severity of inflammatory alterations is partially controlled by the negatively regulating cytokine IL-10, which, on a genetic basis, can be up-regulated to a different extent in individual patients. Therapeutic interventions to improve immune dysfunction include the enhancement of dialysis efficiency and the reduction of inflammatory alterations by the use of highly biocompatible dialyzers.