Complete Regression of Psoriatic Arthritis After Belatacept Conversion in a Highly HLA-Sensitized Kidney Transplant Patient

Costimulatory inhibitors (i.e. abatacept and belatacept) effectively abrogate T lymphocyte activation and proliferation and have been shown to be effective for disease control in certain autoimmune disorders as well as in preventing allograft rejection in kidney transplantation. Whether such immunomodulatory agents may be useful for the control of autoimmune flares and allograft acceptance, while avoiding the need of additional strong immunosuppressants, has not been shown. Here, we report the first case of a 47-year-old man affected by a serious debilitating form of psoriatic arthritis that presented during the course of a third, high immunological-risk kidney transplantation. Three years after transplantation, the patient benefited by switching from tacrolimus- to belatacept-based therapy, without additional immunosuppression, by showing complete regression of the arthritic symptoms as well as no progression of severe radiological lesions, which leaded to the recovery of disability and functional impairment. Remarkably, the treatment with belatacept in association with mycophenolate mofetil and steroids also provided a stable normal allograft function over time and abrogated the development of de novo circulating donor-specific alloantibodies after 4 years of follow-up.

Data on genotypic distribution and linkage disequilibrium of several ANRIL polymorphisms in hemodialysis patients

A long non-coding RNA called ANRIL located on chromosome 9p21.3 has been identified as a novel genetic factor associated with cardiovascular disease. Investigation of several single nucleotide polymorphisms (SNPs) of Noncoding Antisense RNA in the INK4 Locus (ANRIL) gene are of particular interest. This article reports data related to the research article entitled: “Association of ANRIL gene polymorphisms with major adverse cardiovascular events in hemodialysis patients” (Arbiol-Roca et al. [1]). Data presented show the genotypic distribution of four selected ANRIL SNPs: rs10757278, rs4977574, rs10757274 and rs6475606 in a cohort constituted by 284 hemodialysis patients. This article analyzes the Hardy-Weinberg disequilibrium of each studied SNP, and the linkage disequilibrium between them.

Long-Term Outcomes in Belatacept- Versus Cyclosporine-Treated Recipients of Extended Criteria Donor Kidneys: Final Results From BENEFIT-EXT, a Phase III Randomized Study

In the Belatacept Evaluation of Nephroprotection and Efficacy as First-Line Immunosuppression Trial-Extended Criteria Donors (BENEFIT-EXT), extended criteria donor kidney recipients were randomized to receive belatacept-based (more intense [MI] or less intense [LI]) or cyclosporine-based immunosuppression. In prior analyses, belatacept was associated with significantly better renal function compared with cyclosporine. In this prospective analysis of the intent-to-treat population, efficacy and safety were compared across regimens at 7 years after transplant. Overall, 128 of 184 belatacept MI-treated, 138 of 175 belatacept LI-treated and 108 of 184 cyclosporine-treated patients contributed data to these analyses. Hazard ratios (HRs) comparing time to death or graft loss were 0.915 (95% confidence interval [CI] 0.625-1.339; p = 0.65) for belatacept MI versus cyclosporine and 0.927 (95% CI 0.634-1.356; p = 0.70) for belatacept LI versus cyclosporine. Mean estimated GFR (eGFR) plus or minus standard error at 7 years was 53.9 ± 1.9, 54.2 ± 1.9, and 35.3 ± 2.0 mL/min per 1.73 m² for belatacept MI, belatacept LI and cyclosporine, respectively (p < 0.001 for overall treatment effect). HRs comparing freedom from death, graft loss or eGFR <20 mL/min per 1.73 m² were 0.754 (95% CI 0.536-1.061; p = 0.10) for belatacept MI versus cyclosporine and 0.706 (95% CI 0.499-0.998; p = 0.05) for belatacept LI versus cyclosporine. Acute rejection rates and safety profiles of belatacept- and cyclosporine-based treatment were similar. De novo donor-specific antibody incidence was lower for belatacept (p ≤ 0.0001). Relative to cyclosporine, belatacept was associated with similar death and graft loss and improved renal function at 7 years after transplant and had a safety profile consistent with previous reports.

Human adipose tissue-derived mesenchymal stem cells abrogate plasmablast formation and induce regulatory B cells independently of T helper cells

Mesenchymal or stromal stem cells (MSC) interact with cells of the immune system in multiple ways. Modulation of the immune system by MSC is believed to be a therapeutic option for autoimmune disease and transplant rejection. In recent years, B cells have moved into the focus of the attention as targets for the treatment of immune disorders. Current B-cell targeting treatment is based on the indiscriminate depletion of B cells. The aim of this study was to examine whether human adipose tissue-derived MSC (ASC) interact with B cells to affect their proliferation, differentiation, and immune function. ASC supported the survival of quiescent B cells predominantly via contact-dependent mechanisms. Coculture of B cells with activated T helper cells led to proliferation and differentiation of B cells into CD19(+) CD27(high) CD38(high) antibody-producing plasmablasts. ASC inhibited the proliferation of B cells and this effect was dependent on the presence of T cells. In contrast, ASC directly targeted B-cell differentiation, independently of T cells. In the presence of ASC, plasmablast formation was reduced and IL-10-producing CD19(+) CD24(high) CD38(high) B cells, known as regulatory B cells, were induced. These results demonstrate that ASC affect B cell biology in vitro, suggesting that they can be a tool for the modulation of the B-cell response in immune disease.

Use of mycophenolate in ANCA-associated renal vasculitis: 13 years of experience at a university hospital

INTRODUCTION

Standard therapy with corticosteroids (CS) and cyclophosphamide (CYC) followed by azathioprine has been shown to improve renal and patient survival in ANCA-associated renal vasculitis (rAAV). Mycophenolate mofetil (MF) has been progressively introduced for the treatment of rAAV in the last years because of its immunosuppressive efficacy combined with a lower toxicity profile. In this study, we retrospectively analyse the results of the introduction of MF for maintenance and induction therapy in rAAV in our institution from 2001 to 2013.

RESULTS

We reported 67 patients treated with MF as a maintenance treatment, divided by baseline serum creatinine (>500 µmol/L: Group 1 and <500 µmol/L: Group 2) and treatment schedule. Twenty-nine of the 67 patients were also treated with MF as induction treatment, mostly in Group 2. During the follow-up (2 years after the diagnosis) creatinine levels for serum glomerular filtration rate, ANCA titres, C-reactive protein and percentage of haematuria decreased in all groups. In Group 2, parameters and also relapse rates were similar at 24 months in patients treated with CYC or MF as an induction treatment (Subgroups 2a and 2b, respectively). Median dose of MF in maintenance treatment was 1000 mg daily and prednisone dose was tapered to 10 mg daily from Month 3. After 24 months, 82% of patients remained on MF therapy, 18% had discontinued the treatment, seven of them due to medical indication and two because of gastrointestinal intolerance. The percentage of patients that started renal replacement therapy was irregular in Group 1 depending on the subgroup (25-100%), and 10% in Group 2. Adverse effects, such as neutropenia, infections and neoplasia, were more prevalent in groups treated with CYC.

CONCLUSION

In conclusion, in our patients with rAAV, MF demonstrated to be an effective and well-tolerated option for maintenance treatment. As an induction treatment, MF seems to be similar to CYC for patients with moderate renal failure in the diagnosis.

De novo use of everolimus with elimination or minimization of cyclosporine in renal transplant recipients

BACKGROUND

The purpose of two similarly designed multicenter, prospective, parallel-group, open-label studies was to evaluate early cyclosporine (CsA) elimination versus minimization from an everolimus-CsA-steroid regimen in de novo renal transplant patients.

METHODS

Within 24 hours after transplantation, 170 renal transplant patients received everolimus (trough levels 3-8 ng/mL), CsA, and steroids. Those eligible (n = 114) were randomized (1:1) at 3 months to have CsA elimination by month 4 to 6 (±1 week) with everolimus trough levels maintained at 6 to 12 ng/mL or CsA minimization, until 12 months. The randomized population excluded those who discontinued the study prior to randomization due to adverse events, acute rejection episodes of Banff grade IIb/III, or worsening renal function during the month prior to randomization.

RESULTS

At 12 months, the estimated glomerular filtration rate (Nankivell) with CsA elimination was noninferior versus CsA minimization (P < .0001, α-level 0.05; 90% confidence interval 0.6-8.5) by 7 mL/min/1.73 m(2) (noninferiority margin). Composite efficacy failure was comparable with CsA elimination and CsA minimization (18.9% and 17.5%, respectively, P = 1.000) and no graft loss or death was reported after randomization. Cytomegalovirus infections were rare under everolimus treatment, and no pneumonitis episode was reported.

CONCLUSION

In our selected randomized study population, immediate initiation of everolimus allowed CsA elimination. Renal function was stable on everolimus-based, CsA-free maintenance regimen without compromising efficacy.

Sterile leukocyturia is associated with interstitial fibrosis and tubular atrophy in kidney allograft protocol biopsies

Kidney allograft interstitial fibrosis and tubular atrophy (IF/TA) is associated with a poorer renal function and outcome. In the current clinical practice, an early diagnosis can only be provided by invasive tests. We aimed to investigate the association of sterile leukocyturia with Banff criteria histological findings in kidney allograft protocol biopsies. We studied 348 allograft biopsies from two different European countries performed at 8.5 + 3.5 months after transplantation. In these cases, the presence of sterile leukocyturia (Leuc+, n = 70) or no leukocyturia (Leuc-, n = 278) was analyzed and related to Banff elementary lesions. Only IF/TA was significantly different between Leuc+ and Leuc- groups. IF/TA was present in 85.7% of Leuc+ and 27.7% of Leuc- patients (p < 0.001). IF/TA patients had higher serum creatinine and presence of proteinuria (p < 0.05). Independent predictors of IF/TA were donor age, donor male sex, serum creatinine and Leuc+ (hazard ratio 18.2; 95% confidence interval, 8.1-40.7). The positive predictive value of leukocyturia for predicting IF/TA was 85.7% whereas the negative predictive value was 72.3%. These studies suggest that leukocyturia is a noninvasive and low-cost test to identify IF/TA. An early diagnosis may allow timely interventional measures directed to minimize its impact and improve graft outcome.

Pretransplant immediately early-1-specific T cell responses provide protection for CMV infection after kidney transplantation

Cytomegalovirus (CMV) infection is still a major complication after kidney transplantation. Although cytotoxic CMV-specific T cells play a crucial role controlling CMV survival and replication, current pretransplant risk assessment for CMV infection is only based on donor/recipient (IgG)-serostatus. Here, we evaluated the usefulness of monitoring pre- and 6-month CMV-specific T cell responses against two dominant CMV antigens (IE-1 and pp65) and a CMV lysate, using an IFN-γ Elispot, for predicting the advent of CMV infection in two cohorts of 137 kidney transplant recipients either receiving routine prophylaxis (n = 39) or preemptive treatment (n = 98). Incidence of CMV antigenemia/disease within the prophylaxis and preemptive group was 28%/20% and 22%/12%, respectively. Patients developing CMV infection showed significantly lower anti-IE-1-specific T cell responses than those that did not in both groups (p < 0.05). In a ROC curve analysis, low pretransplant anti-IE-1-specific T cell responses predicted the risk of both primary and late-onset CMV infection with high sensitivity and specificity (AUC > 0.70). Furthermore, when using most sensitive and specific Elispot cut-off values, a higher than 80% and 90% sensitivity and negative predictive value was obtained, respectively. Monitoring IE-1-specific T cell responses before transplantation may be useful for predicting posttransplant risk of CMV infection, thus potentially guiding decision-making regarding CMV preventive treatment.

Cross-validation of IFN-γ Elispot assay for measuring alloreactive memory/effector T cell responses in renal transplant recipients

Assessment of donor-specific alloreactive memory/effector T cell responses using an IFN-γ Elispot assay has been suggested to be a novel immune-monitoring tool for evaluating the cellular immune risk in renal transplantation. Here, we report the cross-validation data of the IFN-γ Elispot assay performed within different European laboratories taking part of the EU RISET consortium. For this purpose, development of a standard operating procedure (SOP), comparisons of lectures of IFN-γ plates assessing intra- and interlaboratory assay variability of allogeneic or peptide stimuli in both healthy and kidney transplant individuals have been the main objectives. We show that the use of a same SOP and count-settings of the Elispot bioreader allow low coefficient variation between laboratories. Frozen and shipped samples display slightly lower detectable IFN-γ frequencies than fresh samples. Importantly, a close correlation between different laboratories is obtained when measuring high frequencies of antigen-specific primed/memory T cell alloresponses. Interestingly, significant high donor-specific alloreactive T cell responses can be similarly detected among different laboratories in kidney transplant patients displaying histological patterns of acute T cell mediated rejection. In conclusion, assessment of circulating alloreactive memory/effector T cells using an INF-γ Elispot assay can be accurately achieved using the same SOP, Elispot bioreader and experienced technicians in kidney transplantation.

Dendritic cells phenotype fitting under hypoxia or lipopolysaccharide; adenosine 5'-triphosphate-binding cassette transporters far beyond an efflux pump

This study examines adenosine 5'-triphosphate-binding cassette (ABC) transporters as a potential therapeutic target in dendritic cell (DC) modulation under hypoxia and lipopolysaccharide (LPS). Functional capacity of dendritic cells (DCs) (mixed lymphocyte reaction: MLR) and maturation of iDCs were evaluated in the presence or absence of specific ABC-transporter inhibitors. Monocyte-derived DCs were cultured in the presence of interleukin (IL)-4/granulocyte-macrophage colony-stimulating factor (GM-CSF). Their maturation under hypoxia or LPS conditions was evaluated by assessing the expression of maturation phenotypes using flow cytometry. The effect of ABC transporters on DC maturation was determined using specific inhibitors for multi-drug resistance (MDR1) and multi-drug resistance proteins (MRPs). Depending on their maturation status to elicit T cell alloresponses, the functional capacity of DCs was studied by MLR. Mature DCs showed higher P-glycoprotein (Pgp) expression with confocal microscopy. Up-regulation of maturation markers was observed in hypoxia and LPS-DC, defining two different DC subpopulation profiles, plasmacytoid versus conventional-like, respectively, and different cytokine release T helper type 2 (Th2) versus Th1, depending on the stimuli. Furthermore, hypoxia-DCs induced more B lymphocyte proliferation than control-iDC (56% versus 9%), while LPS-DCs induced more CD8-lymphocyte proliferation (67% versus 16%). ABC transporter-inhibitors strongly abrogated DC maturation [half maximal inhibitory concentration (IC50 ): P-glycoprotein inhibition using valspodar (PSC833) 5 μM, CAS 115104-28-4 (MK571) 50 μM and probenecid 2·5 μM], induced significantly less lymphocyte proliferation and reduced cytokine release compared with stimulated-DCs without inhibitors. We conclude that diverse stimuli, hypoxia or LPS induce different profiles in the maturation and functionality of DC. Pgp appears to play a role in these DC events. Thus, ABC-transporters emerge as potential targets in immunosuppressive therapies interfering with DCs maturation, thereby abrogating innate immune response when it is activated after ischaemia.

Long-term results of biopsy-guided selection and allocation of kidneys from older donors in older recipients

In our old-for-old program, we discard or allocate older extended criteria donor kidneys to single (SKT) or dual kidney transplantation (DKT) depending on histological Remuzzi's score in recipients older than 60 years. Here, we analyze the long-term results of this program and try to identify independent predictors of patient and graft survival. Between December 1996 and January 2008, we performed 115 SKT and 88 DKT. Discard rate was 15%. Acute rejection incidence was higher in SKT than in DKT (22.6% vs. 11.4%, p = 0.04). Renal function was better in DKT than in SKT up to 5 years after transplantation. Surgical complications were frequent in DKT. Ten-year cumulative graft survival was significantly lower in the SKT group (31% vs. 53%, p = 0.03). In SKT, histological score 4 provided similar graft survival than 3 or less, whereas in DKT score 4, 5 or 6 displayed similar outcome. Finally, independent predictors of graft survival were history of major adverse cardiac event and 1-year serum creatinine, rather than SKT or DKT. In conclusion, this biopsy-guided old-for-old strategy resulted in acceptable long-term graft survival. Our results suggest that DKT should be considered for scores of 5 or 6 only.

Immunomodulatory effect of mesenchymal stem cells on B cells

The research on T cell immunosuppression therapies has attracted most of the attention in clinical transplantation. However, B cells and humoral immune responses are increasingly acknowledged as crucial mediators of chronic allograft rejection. Indeed, humoral immune responses can lead to renal allograft rejection even in patients whose cell-mediated immune responses are well controlled. On the other hand, newly studied B cell subsets with regulatory effects have been linked to tolerance achievement in transplantation. Better understanding of the regulatory and effector B cell responses may therefore lead to new therapeutic approaches. Mesenchymal stem cells (MSC) are arising as a potent therapeutic tool in transplantation due to their regenerative and immunomodulatory properties. The research on MSCs has mainly focused on their effects on T cells and although data regarding the modulatory effects of MSCs on alloantigen-specific humoral response in humans is scarce, it has been demonstrated that MSCs significantly affect B cell functioning. In the present review we will analyze and discuss the results in this field.

Hepatocyte growth factor gene therapy enhances infiltration of macrophages and may induce kidney repair in db/db mice as a model of diabetes

AIMS/HYPOTHESIS

We previously demonstrated hepatocyte growth factor (HGF) gene therapy was able to induce regression of glomerulosclerosis in diabetic nephropathy through local reparative mechanisms. The aim of this study was to test whether bone-marrow-derived cells are also involved in this HGF-induced reparative process.

METHODS

We have created chimeric db/db mice as a model of diabetes that produce enhanced green fluorescent protein (EGFP) in bone marrow cells. We performed treatment with HGF gene therapy either alone or in combination with granulocyte-colony stimulating factor, in order to induce mobilisation of haematopoietic stem cells in these diabetic and chimeric animals.

RESULTS

We find HGF gene therapy enhances renal expression of stromal-cell-derived factor-1 and is subsequently associated with an increased number of bone-marrow-derived cells getting into the injured kidneys. These cells are mainly monocyte-derived macrophages, which may contribute to the renal tissue repair and regeneration consistently observed in our model. Finally, HGF gene therapy is associated with the presence of a small number of Bowman's capsule parietal epithelial cells producing EGFP, suggesting they are fused with bone-marrow-derived cells and are contributing to podocyte repopulation.

CONCLUSIONS/INTERPRETATION

Altogether, our findings provide new evidence about the therapeutic role of HGF and open new opportunities for inducing renal regeneration in diabetic nephropathy.

Determination of ganciclovir in human plasma by ultra performance liquid chromatography-UV detection

OBJECTIVES

Implement a sensitive UHPLC method for the assay of ganciclovir in human plasma.

DESIGN AND METHODS

We developed and validated a chromatographic method coupled to ultraviolet detection for quantification of ganciclovir, with a short run time using a small volume of human plasma. Comparison of system performance was made with respect to analysis time, efficiency and sensitivity.

RESULTS

Correlation coefficients (r) of the calibration curves ranged from 0.999744 to 0.999784. Within-day and between-day imprecision and inaccuracy, specificity and recovery were also evaluated for validation. The method was precise and accurate and the retention time was 0.7 min. The calibration curves were linear between 0.5 and 30 μg/mL. There was a good correlation between HPLC and UHPLC techniques.

CONCLUSIONS

We developed a method that is currently applied in a clinical study assessing GCV plasma concentration variability after ganciclovir and valganciclovir administration.

Intragraft regulatory T cells in protocol biopsies retain foxp3 demethylation and are protective biomarkers for kidney graft outcome

Presence of subclinical rejection (SCR) with IF/TA in protocol biopsies of renal allografts has been shown to be an independent predictor factor of graft loss. Also, intragraft Foxp3+ T(reg) cells in patients with SCR has been suggested to differentiate harmful from potentially protective infiltrates. Nonetheless, whether presence of Foxp3 T(reg) cells in patients with SCR and IF/TA may potentially protect from a deleterious graft outcome has not yet been evaluated. This is a case-control study in which 37 patients with the diagnosis of SCR and 68 control patients with no cellular infiltrates at 6-month protocol biopsies matched for age and time of transplantation were evaluated. We first confirmed that numbers of intragraft Foxp3-expressing T cells in patients with SCR positively correlates with Foxp3 demethylation at the T(reg) -specific demethylation region. Patients with SCR without Foxp3+ T(reg) cells within graft infiltrates showed significantly worse 5-year graft function evolution than patients with SCR and Foxp3+ T(reg) cells and those without SCR. When presence of SCR and IF/TA were assessed together, presence of Foxp3+ T(reg) could discriminate a subgroup of patients showing the same graft outcome as patients with a normal biopsy. Thus, presence of Foxp3+ T(reg) cells in patients with SCR even with IF/TA is associated with a favorable long-term allograft outcome.

In vivo therapeutic efficacy of intra-renal CD40 silencing in a model of humoral acute rejection

The humoral branch of the immune response has an important role in acute and chronic allograft dysfunction. The CD40/CD40L costimulatory pathway is crucial in B- and T- alloresponse. Our group has developed a new small interfering RNA (siRNA) molecule against CD40 that effectively inhibits its expression. The aim of the present study was to prevent rejection in an acute vascular rejection model of kidney transplant by intra-graft gene silencing with anti-CD40 siRNA (siCD40), associated or not with sub-therapeutic rapamycin. Four groups were designed: unspecific siRNA as control; sub-therapeutic rapamycin; siCD40; and combination therapy. Long-surviving rats were found only in both siCD40-treated groups. The CD40 mRNA was overexpressed in control grafts but treatment with siCD40 decreased its expression. Recipient spleen CD40+ B-lymphocytes were reduced in both siCD40-treated groups. Moreover, CD40 silencing reduced donor-specific antibodies, graft complement deposition and immune-inflammatory mediators. The characteristic histological features of humoral rejection were not found in siCD40-treated grafts, which showed a more cellular histological pattern. Therefore, the intra-renal effective blockade of the CD40/CD40L signal reduces the graft inflammation as well as the incidence of humoral vascular acute rejection, finally changing the type of rejection from humoral to cellular.

Tubular epithelial cells transfected with hHGF counteracts monocyte chemotactic protein-1 up-regulation after hypoxia/reoxygenation insult

Acute kidney injury (AKI) which is mainly produced by nephrotoxic or ischemic insults is correlated with a high mortality and morbidity. Proximal tubular epithelial cells (PTEC) play a major role. They are the main target of ischemia/reperfusion injury. PTECs have also been proposed as the effectors of AKI reversibility, but also as the creator of the inflammatory milieu: cytokine, chemokine, and complement expression. An important chemokine implicated in this process is monocyte chemotactic protein-1 (MCP-1) due to its ability to recruit and activate monocytes. Hepatocyte growth factor (HGF) is a pleiotropic factor with mitogenic, anti-apoptotic, and proliferative effects which has recently been studied for its anti-inflammatory and antifibrogenic effects. Our aim was to evaluate the potential inflammatory effect of hypoxia and reoxygenation on rat PTECs. We created a stable human HGF (hHGF) expressing PTEC line that emulated in vivo transfection and analyzed the role of this cell type in the induction and reversibility of AKI. Our results showed the efficiency of transfection with the hHGF gene to promote sustained expression of the protein in the medium (7627.13 +/- 1144.078 to 8211.3 +/- 795.37 pg/mL). When rat PTECs were under a hypoxia/reoxygenation insult, MCP-1 was highly overexpressed (4479.3 +/- 154.3 pg/mL of protein and 5.099 +/- 1.23 times control gene expression). Transfected cells abrogated this effect (288.7 +/- 13.5 pg/mL and 1.169 +/- 0.0759 times control). In conclusion, we observed that the hypoxia/reoxygenation insult stimulated MCP-1 protein secretion in PTECs and that PTECs which were stably transfected and overexpressing hHGF abrogated the inflammatory reaction mediated by hypoxia/reoxygenation, being a suitable model for later studies.

Similar lipid profile but improved long-term outcomes with sirolimus after cyclosporine withdrawal compared to sirolimus with continuous cyclosporine

Renal transplant recipients show an increased risk of cardiovascular disease compared with a nontransplant population. Herein we have shown an analysis of a randomized controlled trial wherein 525 patients receiving a first or second (9.7%) renal allograft from a deceased (89.1%), a living-related (7.8%), or a living-unrelated donor (3.1%) received sirolimus (SRL), cyclosporine (CsA), and steroids (ST) at the time of transplantation with randomization at 3 months after transplantation of 430 eligible patients to continue on SRL-CsA-ST or to have CsA withdrawn with increased SRL trough targets (SRL-ST group). Graft survival, patient survival, and renal function at 5 years were analyzed by average fasting total cholesterol (<or=200 or >200 mg/dL) and triglyceride (<or=240 or >240 mg/dL) subgroups. At 5 years, total, high-density lipoprotein (HDL), and low-density lipoprotein [LDL] cholesterol and triglyceride values were similar between the groups. Statins ( approximately 80% of patients of both groups) were most effective to lower cholesterol ( approximately 50 mg/dL; P < .001; both groups), and fibrates ( approximately 25% of patients of both groups) were most effective to decrease triglycerides ( approximately 100 mg/dL; P < .001; both groups). Renal function and blood pressure were significantly better with SRL-ST. Hypercholesterolemia and hypertriglyceridemia were associated with reduced graft survival, patient survival, and calculated GFR, but the only significant difference was lower graft survival among SRL-CsA-ST patients with hypertriglyceridemia. Cardiovascular-related deaths were reported in 3.7% and 2.8% of patients in the SRL-CsA-ST and SRL-ST groups, respectively. In conclusion, when compared with continuous SRL-CsA-ST, CsA withdrawal at 3 months followed by SRL-ST significantly improved glomerular filtration rate (GFR) and blood pressure without a further increase in lipid parameters or an incidence of untoward effects from hyperlipidemia, despite a 2-fold higher SRL exposure.

Population pharmacokinetics of ganciclovir after intravenous ganciclovir and oral valganciclovir administration in solid organ transplant patients infected with cytomegalovirus

A population pharmacokinetics analysis was performed after intravenous ganciclovir and oral valganciclovir in solid organ transplant patients with cytomegalovirus. Patients received ganciclovir at 5 mg/kg of body weight (5 days) and then 900 mg of valganciclovir (16 days), both twice daily with dose adjustment for renal function. A total of 382 serum concentrations from days 5 and 15 were analyzed with NONMEM VI. Renal function given by creatinine clearance (CL(CR)) was the most influential covariate in CL. The final pharmacokinetic parameters were as follows: ganciclovir clearance (CL) was 7.49.(CL(CR)/57) liter/h (57 was the mean population value of CL(CR)); the central and peripheral distribution volumes were 31.9 liters and 32.0 liters, respectively; intercompartmental clearance was 10.2 liter/h; the first-order absorption rate constant was 0.895 h(-1); bioavailability was 0.825; and lag time was 0.382 h. The CL(CR) was the best predictor of CL, making dose adjustment by this covariate important to achieve the most efficacious ganciclovir exposure.

Successful renal transplantation in a patient with atypical hemolytic uremic syndrome carrying mutations in both factor I and MCP

Kidney transplantation in patients with atypical hemolytic uremic syndrome (aHUS) carrying mutations in the soluble complement regulators factor H (CFH) or factor I (CFI) is associated with elevated risk of disease recurrence and almost certain graft loss. In contrast, recurrence is unusual in patients with mutations in the membrane-associated complement regulator membrane cofactor protein (MCP) (CD46). Therefore, a panel of experts recently recommended the combined liver-kidney transplantation to minimize aHUS recurrence in patients with mutations in CFH or CFI. There was, however, very limited information regarding transplantation in patients carrying mutations in both soluble and membrane-associated complement regulators to support a recommendation. Here, we report the case of an aHUS patient with a heterozygous mutation in both CFI and MCP who received an isolated kidney transplant expressing normal MCP levels. Critically, the patient suffered from a severe antibody-mediated rejection that was successfully treated with plasmapheresis and IvIgG. Most important, despite the complement activation in the allograft, there was no evidence of thrombotic microangiopathy, suggesting that the normal MCP levels in the grafted kidney were sufficient to prevent the aHUS recurrence. Our results suggest that isolated kidney transplantation may be a good first option for care in aHUS patients carrying CFI/MCP combined heterozygous mutations.

[Renal involvement in benign monoclonal gammopathies: an underdiagnosed condition]

Renal involvement is observed frequently in association with malignant gammopathies, mainly those related to light chain deposition, although has also been described in non-malignant monoclonal gammopathy. This study reports the clinicopathological findings and outcome in 9 patients with nephropaty secondary to monoclonal immunoglobulin deposit in absence of malignancy. They were three men and six women and they were 59.2+/-12 years old. All patients presented proteinuria and different levels of renal insufficiency (mean creatinin = 315+/-187 micromol/L) at the moment of diagnostic. Two patients required dialysis at the time of renal biopsy. The pathology studies revealed a nodular sclerosing glomerulopathy in four cases, mesangiocapilary glomerulonephritis in three cases, only tubular lesions in one and mesangial lesions in the other one. The treatment applied was: Prednisone alone (two cases), with chemotherapy associated (melfalan in two, clorambucil in one and ciclophosphamide in another one). One patient received plasmapheresis and mycophenolate and another patient undergone a bone marrow authotransplant associated to mycophenolate and prednisone. One of the two patients who required dialysis at the moment of presentation was not treated. After a follow-up of more than 4 years (4.89 +/-DE: 3.69) renal function improved or remained stable in three patients and proteinuria was disappeared in more than 50% of patients. Four patients had a worsening of renal function and they required dialysis during the time of follow-up (in 2,4 years +/- DE: 4,3). In any case malignitation was observed. Chemotherapy stabilized or improved renal function in 3 of nine patients (33%) with non-malignant monoclonal gammopathy. Non-malignant monoclonal gammopathy could go unnoticed. Appearance of abnormalities in renal routine tests deserves more in-depth diagnostic procedures, including renal biopsy. Evolution to end stage renal disease could probably be avoided or reduced in severity with early detection and treatment of this entity.

Immunephenotype of glomerular and interstitial infiltrating cells in protocol renal allograft biopsies and histological diagnosis

Patients with a protocol renal allograft biopsy simultaneously displaying interstitial fibrosis/tubular atrophy (IF/TA) and subclinical rejection (SCR) have a shortened graft survival than patients with a normal biopsy, or with a biopsy only displaying IF/TA or SCR. The poor outcome of these patients could be related with a more severe inflammation. We evaluate the immunophenotype of infiltrating cells in these diagnostic categories. Nonexhausted paraffin blocks from protocol biopsies done during the first year were stained with anti-CD45, CD3, CD20, CD68 and CD15 monoclonal antibodies. Glomerular and interstitial positive cells were counted. C4d deposition in peritubular capillaries was evaluated. Histological diagnoses were: normal (n = 80), SCR (n = 17), IF/TA (n = 42) and IF/TA + SCR (n = 17). Only interstitial CD20 positive cells were significantly increased in patients displaying IF/TA + SCR; normal (137 +/- 117), SCR (202 +/- 145), IF/TA (208 +/- 151) and IF/TA + SCR (307 +/- 180 cells/mm(2)), p < 0.01. The proportion of biopsies displaying C4d deposition was not different among groups. The upper tertile of CD20 positive interstitial cells was associated with a decreased death-censored graft survival (relative risk: 3.01, 95% confidence interval: 1.23-7.35; p = 0.015). These data suggest that B-cell interstitial infiltrates are associated with histological damage and outcome, but do not distinguish whether these infiltrates were the cause or the consequence of chronic tubulo-interstitial damage.

Donor Structural and Functional Parameters Are Independent Predictors of Renal Function at 3 Months

INTRODUCTION

Epidemiological studies have shown that demographic, clinical, and histological donor characteristics influence renal function after transplantation, but whether these variables are independent predictors has not been established. The aim of this study was to evaluate the relative contribution of different donor variables on glomerular filtration rates (GFRs) at 3 months.

PATIENTS AND METHODS

We analyzed single renal transplants performed at our center from January 2000 to July 2004. Donor variables included age, gender, weight and height, cause of death, duration of brain death, serum creatinine at admission and preprocurement, history of arterial hypertension or diabetes mellitus, and smoking habit. Donor chronic damage score was calculated in preimplantation biopsies as was the addition of interstitial fibrosis, fibrous intimal thickening, and glomerulosclerosis (<10% = 0, >10% = 1). Donor and recipient GFRs were calculated according to the Cockroft-Gault formula.

RESULTS

We analyzed 202 transplants obtained from 113 deceased donors. A renal biopsy was available in 111 transplants. Recipient GFR at 3 months correlated negatively with donor age (R = -0.32, P < .01) and donor chronic damage score (R = 0.32, P < .01). GFR was lower among recipients of female versus male donors (50 +/- 15 vs 60 +/- 20 mL/min; P < .01). Donor cerebrovascular accident death (53 +/- 19 vs 63 +/- 19 mL/min; P < .01) and hypertension (48 +/- 16 vs 59 +/- 20 mL/min; P < .01) were also associated with lower GFR at 3 months. There was a positive correlation between GFR at admission, GFR preprocurement, and GFR at 3 months (R = 0.32 and R = 0.18 respectively; P < .01). Stepwise regression analysis included chronic damage score, GFR at admission, and donor gender but not donor age as independent predictors of GFR at 3 months (R = 0.50; P < .01).

CONCLUSION

Donor structural and functional parameters are independent predictors of renal function at 3 months.

New immunosuppresor strategies in the treatment of murine lupus nephritis

Renal involvement in systemic lupus erythematosus is a common complication that significantly worsens morbidity and mortality. Although treatment with corticosteroids and cytotoxic drugs may be useful in many cases, morbidity associated with these drugs and the relapsing nature of the disease make it necessary to develop new treatment strategies. Five-month old female NZB/W F1 mice were divided into the following groups: CYP group (n = 10), cyclophosphamide (CYP) 50 mg/kg intraperitoneally every 10 days; RAPA 1 group (n = 10) oral daily sirolimus (SRL), 1 mg/kg; RAPA 12 group (n = 13), oral daily SRL, 12mg/kg; FTY group (n = 10), oral fingolimod (FTY720), 2 mg/kg three times per week. An additional group of 13 non-treated mice were used as a control (control group). Follow-up was performed over four months. Animal survival, body weight, anti-DNA antibodies and proteinuria were determined. Kidneys were processed for conventional histology and immunofluorescence for IgG and complement. Total histological score (HS) was the sum of mesangial expansion, endocapillary proliferation glomerular deposits, extracapillary proliferation, interstitial infiltrates, tubular atrophy and interstitial fibrosis. All treated groups had lower proteinuria at the end of the follow-up with respect to the control group (P < 0.0001). Serum anti-DNA antibodies were appropriately controlled in RAPA 1 and CYP groups, but not in FTY or RAPA 12 groups. SRL and CYP arrested, and perhaps reversed almost all histological lesions. FTY720 ameliorated histological lesions but did not control mesangial expansion or interstitial infiltrates. SRL produces great improvement in murine lupus nephritis, while FTY720 seems a promising alternative if used in appropriate doses.

Immunosuppression for dual kidney transplantation with marginal organs: the old is better yet

Immunosuppressive protocols in dual kidney transplantation (DKT) are based on calcineurin inhibitors (CNI). We wonder whether a CNI-free immunosuppression can improve outcome in older patients receiving a DKT with marginal donor organs. Thirty-six were treated with CsA, MMF and prednisone (CsA group) and 42 with rATG, SRL, MMF and prednisone (SRL group). Incidence of delayed graft function and acute rejection was 44% and 11% in the CsA group, and 40% and 8% in the SRL group. CMV infection incidence was low in both protocols. Three-year patient survival was 89% in the CsA and 76% in the SRL group. One- and 3-year graft survival after censoring for dead with a functioning allograft was 94.2% and 94% in CsA and 95% and 90% in SRL, respectively. Renal function was similar in both groups whereas proteinuria was higher in the SRL group. Uninephrectomy due to graft thrombosis or urinary-related complications was numerically higher in the SRL (21%) than in the CsA group (8%) (p = 0.13) and it was associated with renal failure and proteinuria. In DKT, a new induction immunosuppressive protocol based on rATG, SRL, MMF and prednisone does not offer any advantage in comparison to the old CsA, MMF and prednisone.

Mycophenolate mofetil and sirolimus combination in renal transplantation

Mycophenolate mofetil (MMF) and sirolimus (SRL) are potent non-nephrotoxic xenobiotic immunosuppressants. Their complementary properties may provide the rationale for their combination in induction and maintenance regimens. MMF, a reversible inhibitor of inosin monophosphate dehydrogenase (IMPDH) acts as an antiproliferative drug; and SRL, an mTOR (mammalian target of rapamycin) inhibitor, inhibits cell proliferation driven by growth factors. Early experiences with the use of the SRL, MMF and steroid combination yielded insufficient prophylaxis of acute rejection. However, the introduction of induction therapy with mono- or polyclonal antilymphocyte antibodies to the SRL-MMF and steroid combination brings an efficient acute rejection prophylaxis, while improving renal function and/or reducing of chronic allograft nephropathy (CAN). However, adverse events related to the use of this drug combination (mainly haematological and surgery-related) result in a high rate of discontinuations in some trials, which may hamper the potential benefits of this calcineurin-inhibitor (CNI)-free strategy. Also, currently under investigation is whether in long-term immunosuppression, in MMF-treated patients, CNIs can be replaced by SRL to avoid and/or halt progression of chronic nephropathy and to improve graft survival. However, some authors reported a high proportion of patients with oral ulcers and proteinuria after switching to SRL. In short, refining the use of MMF and SRL may provide a better risk/benefit ratio to pave the way towards non-nephrotoxic immunosuppression.

Mycophenolate mofetil and sirolimus combination in renal transplantation

Mycophenolate mofetil (MMF) and sirolimus (SRL) are potent non-nephrotoxic xenobiotic immunosuppressants. Their complementary properties may provide the rationale for their combination in induction and maintenance regimens. MMF, a reversible inhibitor of inosin monophosphate dehydrogenase (IMPDH) acts as an antiproliferative drug; and SRL, an mTOR (mammalian target of rapamycin) inhibitor, inhibits cell proliferation driven by growth factors. Early experiences with the use of the SRL, MMF and steroid combination yielded insufficient prophylaxis of acute rejection. However, the introduction of induction therapy with mono- or polyclonal antilymphocyte antibodies to the SRL-MMF and steroid combination brings an efficient acute rejection prophylaxis, while improving renal function and/or reducing of chronic allograft nephropathy (CAN). However, adverse events related to the use of this drug combination (mainly haematological and surgery-related) result in a high rate of discontinuations in some trials, which may hamper the potential benefits of this calcineurin-inhibitor (CNI)-free strategy. Also, currently under investigation is whether in long-term immunosuppression, in MMF-treated patients, CNIs can be replaced by SRL to avoid and/or halt progression of chronic nephropathy and to improve graft survival. However, some authors reported a high proportion of patients with oral ulcers and proteinuria after switching to SRL. In short, refining the use of MMF and SRL may provide a better risk/benefit ratio to pave the way towards non-nephrotoxic immunosuppression.

Subclinical rejection impairs glomerular adaptation after renal transplantation

After transplantation, glomerular volumes increases and large glomerular volume at 4 months is associated with better renal function. The aim is to characterize glomerular adaptation after the fourth month in two serial protocol biopsies and its relationship with subclinical rejection and chronic allograft nephropathy (CAN). Mean glomerular volume (Vg) was estimated according to the Weibel and Gomez method in a 4-month and 1-year serial protocol biopsies in 61 stable grafts. Glomerular enlargement (deltaVg) was calculated as the Vg difference between both biopsies. Banff schema was used to evaluate renal biopsies. Vg increased from 4.4+/-2.4 to 5.7+/-2.6 x 10(6) microm3 (P<0.001). Mean deltaVg was 1.0 x 10(6) microm3. Patients with deltaVg<1 were considered as patients with impaired glomerular enlargement (n=29). Impaired glomerular enlargement was associated with increased acute index score in the 4-month (1.83+/-1.56 vs 1.06+/-1.48; P<0.05) and 1-year protocol biopsies (1.52+/-1.59 vs 0.62+/-1.07; P<0.05). Impaired glomerular enlargement was also associated with increased progression of chronic lesions between the 4-month and 1-year biopsy in the glomerular (0.17+/-0.38 vs 0.55+/-0.63; P<0.01), tubular (0.38+/-0.56 vs 0.83+/-0.85; P<0.01), and interstitial compartment (0.41+/-0.57 vs 0.90+/-0.86; P<0.01). The proportion of sclerotic glomeruli between both biopsies increased in patients with impaired glomerular enlargement (1.5+/-3.9 to 5.3+/-10.1, P<0.05) while it did not modify in patients with glomerular enlargement (2.1+/-7.3 vs 2.6+/-4.5; P=NS). During the first year, glomeruli enlarge but this adaptation mechanism is impaired in patients with subclinical rejection. Moreover, impaired glomerular enlargement is associated with progression of CAN.

HGF gene therapy attenuates renal allograft scarring by preventing the profibrotic inflammatory-induced mechanisms

Inflammatory processes and tissue scarring are characteristic features of chronic allograft nephropathy. Hepatocyte growth factor (HGF) has beneficial effects on renal fibrosis and it also ameliorates renal interstitial inflammation as it has been recently described. Contrarily to protein administration, intramuscular gene electrotransfer allows sustained release of HGF. So, here we hypothesized that gene therapy with human HGF would diminish the characteristic scarring of chronic allograft nephropathy either by antagonizing tissue fibrosis mechanisms or by reducing inflammation. Lewis rats transplanted with cold preserved Fischer kidneys received vehicle (NoHGF) or intramuscular plasmid DNA encoding HGF plus electroporation either before transplantation (IniHGF, early post-transplant cytoprotection of tubular cells) or 8/10 weeks after transplantation (DelHGF, delayed prevention of chronic mechanisms). Serum creatinine and proteinuria were measured every 4 weeks for 24 weeks. Grafts at 12 or 24 weeks were evaluated for glomerulosclerosis, fibrosis inflammatory cells and mediators, cell regeneration and tubulo-interstitial damage. Nontreated animals developed renal insufficiency, progressive proteinuria and fibrosis among other characteristic histological features of chronic allograft nephropathy. Treatment with human HGF, especially when delayed until the onset of fibrogenic mechanisms, reduced renal failure and mortality, diminished tubule-interstitial damage, induced cell regeneration, decreased inflammation, NF-kappaB activation, and profibrotic markers at 12 weeks and prevented late interstitial fibrosis and glomerulosclerosis. The effectiveness of HGF-gene therapy in the prevention of renal allograft scarring is related with the halt of profibrotic inflammatory-induced mechanisms.

Subclinical rejection associated with chronic allograft nephropathy in protocol biopsies as a risk factor for late graft loss

Chronic allograft nephropathy (CAN) in protocol biopsies is associated with graft loss while the association between subclinical rejection (SCR) and outcome has yielded contradictory results. We analyze the predictive value of SCR and/or CAN in protocol biopsies on death-censored graft survival. Since 1988, a protocol biopsy was done during the first 6 months in stable grafts with serum creatinine <300 micromol/L and proteinuria <1 g/day. Biopsies were evaluated according to Banff criteria. Borderline changes and acute rejection were grouped as SCR. CAN was defined as presence of interstitial fibrosis and tubular atrophy. Mean follow-up was 91 +/- 46 months. Sufficient tissue was obtained in 435 transplants. Biopsies were classified as normal (n = 186), SCR (n = 74), CAN (n = 110) and SCR with CAN (n = 65). Presence of SCR with CAN was associated with old donors, percentage of panel reactive antibodies and presence of acute rejection before protocol biopsy. Cox regression analysis showed that SCR with CAN (relative risk [RR]: 1.86, 95% confidence interval [CI]: 1.11-3.12; p = 0.02) and hepatitis C virus (RR: 2.27, 95% CI: 1.38-3.75; p = 0.01) were independent predictors of graft survival. In protocol biopsies, the detrimental effect of interstitial fibrosis/tubular atrophy on long-term graft survival is modulated by SCR.

Long-term effect of hepatitis C virus chronic infection on patient and renal graft survival

BACKGROUND

Hepatitis C virus (HCV) infection increases morbimortality in renal transplantation. The immune response against the HVC is not predictable in a great proportion of patients developing into chronic liver disease, glomerulonephritis, or both.

PATIENTS

We analyzed the impact of posttransplant chronic hepatitis development on patient and graft survival in 200 HCV-positive/HBsAg-negative renal allograft recipients transplanted between 1981 and 2003.

RESULTS

Ninety-eight patients developed chronic ALT elevation (ALT+), while 102 did not (ALT-). There was no difference in acute rejection episodes (ARE), acute tubular necrosis, donor and recipient age, gender, HLA mismatches, and number of previous renal transplants. Development of ALT+ was associated with a worse patient survival (90% vs 65% at 15 years of follow-up, P = .007; RR = 3.8, CI = 1.4-10.1), an effect that was independent of other variables as time on dialysis and age. The main causes of death among ALT+ were chronic liver disease (52%), cardiovascular (26%), and infection (13%), whereas in ALT- they were cardiovascular (33%), cancer (33%), and chronic liver disease (16%). Conversely, graft survival (censoring for patient death with a functioning graft) was higher among ALT+ (50% vs 35% at 15 years of follow-up, P = .04; RR = 1.5, CI = 1.19-2.22). Causes of graft loss in ALT- patients were chronic allograft nephropathy (CAN, 53%), glomerulonephritis (GN, 18%), acute rejection episode (AR, 22%), and death (5%), whereas among ALT+ they were CAN (36%), GN (31%), ARE (10%), and death (21%; P = .01). By multivariate analysis, ALT- (RR = 1.6, CI = 1.07-2.55, P = .02) and de novo GN (RR = 2, CI = 1.29-3.09, P = .002) were associated with worse renal allograft survival.

CONCLUSION

Our results suggested that a better immune response against the HCV lead to greater patient survival but poorer graft survival.

Calcineurin-inhibitor-sparing immunosuppressive protocols

Calcineurin inhibitors (CNI) have played an important role in improving graft survival. However, the balance between preventing immunologic allograft losses and the management of CNI-related nephrotoxicity is still an issue in renal transplantation. There are three major CNI-sparing strategies. CNI MINIMIZATION: The advent of mycophenolate mofetil (MMF) allows cyclosporine (CsA) reduction to ameliorate renal function in patients with chronic renal allograft dysfunction, without increasing acute rejection rates. In combination with mTOR inhibitors, very low CNI levels may be sufficient to prevent acute rejection. However, in this association, CNI nephrotoxicity is magnified by pharmacokinetic interaction. CNI WITHDRAWAL: CNI withdrawal has been attempted in regimens containing MMF or sirolimus (SRL). Introduction of MMF in patients with chronic allograft nephropathy (CAN) followed by CNI withdrawal resulted in stabilization or improvement of renal function and hypertension profile, although there is some risk of acute rejection. In regimes based on SRL, CNI withdrawal is a safety strategy, achieving a sustained improvement of renal function, histology, and graft survival. There is not consensus at all whether MMF should be added or not in patients converted from CNI to mTOR inhibitor. CNI AVOIDANCE: Polyclonal-based regimens with MMF and steroids have shown acceptable acute rejection rates, but high rates of cytomegalovirus (CMV) and opportunistic infections. Conversely, anti-IL-2R in combination with MMF and steroids resulted in 50% incidence of acute rejection, thus suggesting that CNI avoidance is not feasible in a regimen based on MMF. Alternatively, a protocol based on anti-IL-2R induction therapy combined with SRL, MMF, and prednisone has shown an efficient prevention of acute rejection, higher creatinine clearance and lower rate of CAN in comparison with a group treated with CNI. New strategies using costimulation blockade may help in the development of safe CNI-free regimens. In summary, in renal transplantation the new immunosuppressive medications have made feasible old aspirations such as minimization, withdrawal, or even avoidance of CNI.

Glomerular size in early protocol biopsies is associated with graft outcome

Long-term consequences of glomerular enlargement after transplantation are not well understood. The aim is to evaluate the relationship between glomerular volume (Vg) estimated in protocol biopsies, graft function and graft survival. Vg and Banff chronic damage score were evaluated in protocol biopsies at 4 months. Creatinine clearance (CrCl) was estimated by the Cockroft-Gault formula. Vg estimated in 144 patients was 4.8 +/- 2.0 x 10(6)mu(3). It was associated with donor age (r = 0.23, p < 0.01), recipient body mass index (r = 0.17, p = 0.04), delayed graft function (Vg = 5.9 +/- 2.3 vs. 4.6 +/- 1.9 x 10(6)mu(3), p < 0.01) and CrCl (r = 0.17, p = 0.04). The best cutoff of Vg, Banff chronic damage score and CrCl was determined by Cox regression analysis, being 5.0 x 10(6)mu(3) for Vg (relative risk (RR): 2.4, 95% confidence interval (CI): 1.03-5.6), >2 for chronic damage score (RR: 3.4, 95% CI: 1.03-8.9) and 60 mL/min for CrCl (RR: 3.5, 95% CI: 1.04-11.9). These variables were independent predictors of death-censored graft survival. According to Vg and CrCl, four groups of patients were defined. Patients with small glomeruli and high CrCl had a 95% graft survival while patients with large glomeruli and low CrCl had a 45% graft survival at 15 years (p < 0.01). Large glomerular volume, high Banff chronic score and poor early renal function in stable grafts are independently associated with death-censored graft survival.

Role of Cold Ischemia in Acute Rejection: Characterization of a Humoral-Like Acute Rejection in Experimental Renal Transplantation

The aim of the study was to characterize the role of cold ischemia in the process of acute rejection using an experimental renal transplant model. Syngeneic renal transplants were performed between Wistar Agouti rats and allogeneic grafts using Wistar-Agouti rats as recipients of Brown-Norway kidneys. For cold ischemia (CI), kidneys were preserved in Euro-Collins (4 degrees C/ 2.5 hours). Rats were bilaterally nephrectomized at the moment of renal transplant and did not receive any immunosuppressant. The groups were NoAR (n = 6): immediate syngeneic transplant; CI-NoAR (n = 6): syngeneic transplant with CI; AR (n = 13): immediate allogeneic graft; CI-AR (n = 6): allogeneic graft with CI. Allogeneic rats were followed for the survival study. Syngeneic rats, with mean survival time beyond 6 months, were sacrificed on the day 7 to compare grafts with those in the allogeneic groups. H&E- and PAS-stained grafts were evaluated using the Banff criteria. Tissue INF-gamma and TNF-alpha were quantified by RT-real time-PCR on the kidney grafts. Renal insufficiency did not appear in the NoAR group, but it did from the posttransplant day 5 in both acute rejection groups. While NoAR kidneys showed well-conserved renal architecture, then AR group displayed variable degrees of tubular necrosis with scarce cellular infiltration, interstitial hemorrhage, vascular damage with fibrinoid necrosis, perivascular edema, and nuclear disruption. Cold ischemia in rejecting animals increased the mortality rate due to renal insufficiency and accelerated acute rejection. Independently of CI, the proinflammatory cytokines TNF-alpha and INF-gamma were increased in both rejection groups. In conclusion, addition of CI overactivates the acute rejection process via a humoral component.

Arterial Elasticity Measurement in Renal Transplant Patients Under Anticalcineurin Immunosuppression

INTRODUCTION

Calcineurin inhibitors may be associated with decreased arterial elasticity and increased vascular risk. We measured pulse wave velocity (PWV) in large or small arteries as an index of elasticity. The aim of our study was to determine aortic and radial arterial elasticity in 30 stable kidney transplant patients treated with calcineurin inhibitor immunosuppression.

PATIENTS AND METHODS

In stable kidney transplant patients we determined the usual biochemical parameters as well as lipid profiles, 24-hour blood pressure (BP) monitoring (CBPM) using a chronobiological program (Garapa), and PWV with a HDI-PWV CR-2000 monitor.

RESULTS

Sixteen patients received cyclosporine (CsA, G-1) and 14 tacrolimus (G-2) immunosuppression. There were no baseline differences regarding age (G-1: 56 +/- 12 years, G-2: 56 +/- 14 years), renal transplant follow-up (G-1: 7 +/- 3 years, G-2: 7.5 +/- 3 years), Systolic BP, pulse pressure or plasma creatinine (G-1: 163 +/- 35 umol/L, G-2: 173 +/- 26 umol/L). Patients in the G-1 showed higher diastolic BP (79 +/- 11 vs 74 +/- 8 mm Hg), greater proteinuria (1.26 +/- 0.4 vs 0.6 +/- 0.2 g/d, P < .05), total cholesterol (5.51 +/- 1.2 mmol/L) and low-density lipoprotein (3.08 +/- 0.3 vs 2.99 +/- 0.3 mmol/L, P = NS). Aortic arterial elasticity was decreased in G-1 patients (10.4 +/- 6 vs 14.3 +/- 2 mL/mm Hg x10, P < .05) as well as that in the radial artery (G-1: 5.52 +/- 1 vs 5.57 +/- 1.2 mL/mm Hg x100, P = NS). Almost 100% of the patients presented normal diurnal BP with high nocturnal BP in a nondipper pattern in both groups.

CONCLUSION

Calcineurin immunosuppression may contribute to arterial stiffness in kidney transplant patients. No differences between CsA or tacrolimus were observed in our study. CBPM and PWV are useful tools to evaluate subclinical atherosclerosis in renal transplant patients.

Therapy With Plasmapheresis and Intravenous Immunoglobulin for Acute Humoral Rejection in Kidney Transplantation

BACKGROUND

Acute humoral rejection (AHR) is characterized by acute graft dysfunction associated with de novo production of donor-specific alloantibodies (DSA) and C4d deposition in peritubular capillaries of the renal allograft. It has been reported the combination of plasmapheresis (PP) and intravenous gamma globulin (IVIG) as effective rescue therapy for established AHR.

METHODS

Between 1999 and 2004, seven kidney allografts recipients suffered from AHR diagnosed by severe rejection and C4d staining in peritubular capillaries. All patients had a negative cross-match before renal transplantation.

RESULTS

All patients were treated with daily sessions of PP and in four cases IVIG was added after the last PP session. Tacrolimus and mycophenolate mofetil were employed as maintenance immunosuppressive regimen. In one case, rituximab was added to PP and IVIG owing to refractory humoral rejection. At 1 year, patient survival was 100%, allograft survival was 70%, and the mean serum creatinine was 201 micromol/L.

CONCLUSIONS

AHR is a severe form of rejection associated with a poor prognosis, but its early diagnosis and treatment with PP and IVIG allows reversal of AHR reaching a 70% graft survival at 1 year.

Direct electrotransfer of hHGF gene into kidney ameliorates ischemic acute renal failure

In the early phase of kidney transplantation, the transplanted kidney is exposed to insults like ischemia/reperfusion, which is a leading cause of acute renal failure (ARF). ARF in the context of renal transplantation predisposes the graft to developing chronic damage and to long-term graft loss. Hepatocyte growth factor (HGF) has been suggested to support the intrinsic ability of the kidney to regenerate in response to injury by its morphogenic, mitogenic, motogenic and antiapoptotic activities. In the present paper, we examine whether human HGF (hHGF) gene electrotransfer helps in the recovery from ARF in a model of rat renal warm ischemia. We also assess the advantages of this form of gene therapy by direct electroporation of the kidney, given that transplantation offers the possibility of manipulating the organ in vivo. We have compared the therapeutic efficiency of two electroporation methodologies in a rat ARF model. Although they both targeted the same organ, the two methods were applied to different parts of the animal: muscle and kidney. Kidney direct electrotransfer was shown to be more efficient not only in pharmacokinetic but also in therapeutic terms, so it may become a clinically practical alternative in renal transplantation.

Beneficial effect of concomitant induction with antilymphoblast globulin, cyclosporine, and steroids on long-term renal allograft outcome

BACKGROUND

The addition of induction therapy with antilymphocytic antibodies to cyclosporine (CsA) based immunosuppression, has reduced acute rejection incidence and improved short-term survivals, but has not had well-established effects on long-term renal transplant survival.

PATIENTS

We analyzed the long-term allograft outcome of patients included in a prospective randomized clinical study conducted in our center 15 years ago by comparing two strategies: (A) horse antilymphoblast globulin (ALG) given at 10 mg/kg on alternate days to a maximum of 6 doses with low-dose CsA started at 8 mg/kg per day and prednisone at 0.25 mg/kg per day, versus (B) CsA started at 15 mg/kg per day and prednisone at 0.5 mg/kg per day. Diabetic and highly sensitized patients (PRA > 70%) were excluded from the study.

RESULTS

The characteristics of the 50 patients enrolled in each group were not different. Although patient survival was not different (88% in group A vs 77% in group B), recipients treated with ALG showed a lower incidence of acute rejection episodes (20% vs 44%, P = .01) and better death-censored renal allograft survival (57% vs 41%, P = .03). Among rejection-free patients, graft survival was 15% higher in group A (60% vs 45%, P = .12). Multivariate Cox regression analysis showed that an acute rejection episode (relative risk [RR]: 2.44, 95% confidence interval [CI] 1.36-4.39; P = .0029) rather than ALG immunosuppression (RR 0.74, 95% CI 0.41-1.33; P = NS) was an independent predictor of death-censored graft survival.

CONCLUSIONS

In summary, we confirmed that concomitant induction therapy with ALG, CsA, and steroids improves long-term renal allograft survival.

Cyclosporine nephrotoxicity

The polypeptide immunosuppressant cyclosporine is a prodrug that binds an intracellular immunophilin. The complex cyclosporine-cyclophilin binds and inhibits the phosphatase activity of calcineurin interfering with the dephosphorilation of members of the nuclear factor of activated T cells, which is involved in the regulation of genes encoding many cytokines. However, calcineurin is not exclusive from T cells; it is also present in many organs, such as the kidney, and their inhibition accounts for both the immunosuppressive and the nephrotoxic effects of cyclosporine. In renal transplantation, it was shown that graft survival improved progressively between 1998 to 1996, mainly due to reduction of acute rejection episodes. There is no doubt that cyclosporine contributed to that success. After 20 years, cyclosporine targets for maintenance immunosuppression have not been defined and the magnitude of chronic cyclosporine nephrotoxicity in renal allografts is not known, in part by the limitations of histologic classification of chronic allograft nephropathy. In the future, the new technology based on DNA microarrays can be a valuable tool to separate chronic drug toxicity from other causes of graft deterioration. On the other hand, in the cyclosporine era, chronic renal failure has emerged as a frequent adverse event after transplantation of nonrenal organs and it is associated with increased risk of death. Although there is not yet enough evidence to support a generalization of calcineurin-free immunosuppression, we should open our minds to the upcoming new concepts on immunosuppression.

Optimizing cadaveric organ procurement: the catalan and Spanish experience

The need to face the increasing gap between the supply and the demand of transplants has led to the development of a permanent network of trained medical staff responsible for the organ donation and removal process in all centers accredited for that process. In Spain, this activity received a specific budget, like any other medical activity in hospitals, and the responsible staff became accountable for performance. This system dramatically increased the number of potential donors referred, not only young donors with trauma, but also elderly donors dying from stroke. The effect was that the donation rate increased by more than 100% in 10 years (from 14 to 34 donors per million population). Consequently, so did all the transplant figures. In some areas, such as Catalonia, it has been demonstrated that sustained kidney transplant activity of over 60 procedures per million population can maintain or slightly decrease the waiting list, despite increasing incidence and prevalence of end-stage renal failure. Quality monitoring of the donation and retrieval process shows that there are still opportunities for improvement if all potential donors are referred and all technical problems are overcome. Living donation and nonheart beating organ retrieval should also be promoted.

Doxazosin GITS trough to peak ratio and 24-hour blood pressure monitoring in the management of hypertension in renal transplant patients

We have studied 20 patients, 10 male, 10 female, mean age 52.5+/-10.9 years, who received a cadaver kidney transplant between June 1996 and January 1999. The patients presented with mild or moderate high BP and were treated on a maintained immunosuppression with an anti-calcineurin agent and steroids, associated or not to mycophenolate-mofetil. At baseline, a 24-hour ambulatory BP monitoring was performed. General biochemical parameters were determined and doxazosin GITS (Gastro-Intestinal Therapeutic System) in a single dose of 4 mg/d was started. Doxazosin GITS was titrated four weeks after up to 8 mg/d if the BP was greater than 140/90 mm Hg. At week 12, biochemical analysis were repeated as well as the 24-hour BP monitoring and the T/P ratio was calculated.

RESULTS

The patients were divided in responders, T/P index >50%, n=10 or not-responders, T/P index <50%, n=10 patients). No differences in systolic BP (SBP), diastolic BP(DBP), plasma creatinine or proteinuria were seen at base-line. DBP was lower in responders than in non-responders (P=ns). Doxazosin doses were 5.5+/-3 mg/d vs 5.8+/-3 and T/P ratio 0.70+/-0.13 vs 0.17+/-0.14, (P=.001). There were no variations in pl. t. cholesterol, triglycerides, glucose or uric acid.

CONCLUSIONS

Treatment was safe and efficient, not increasing metabolic adverse effects. Doxazosin GITS is a safe agent which can reduce cardiovascular risk. In our patients, the good T/P ratio has been associated with a best diastolic BP control. This good profile should be taken into account for 24-hour BP control in hypertensive renal transplant patients.

[Effect of cyclosporin and tacrolimus on lipoprotein oxidation after renal transplantation]

BACKGROUND

Cyclosporin A is a lipogenic immunosuppressor that can induce posttransplant hyperlipidaemia. Oxidation of low-density lipoprotein (LDL) has been recognized as a major atherogenic factor. Tacrolimus seems to be less lipogenic with an apparently better cardiovascular profile than CsA.

METHODS

We have studied the lipidic profile and the oxidation of HDL and LDL in 20 renal transplant patients, 12 male and 8 female, mean age 45 +/- 10 year, who where switched from CsA to tacrolimus due to CsA adverse effects. LDL were determined by ultracentrifugation. Oxidation study before and 6 months after conversion to tacrolimus was performed by adding CuSO4.

RESULTS

After conversion, systolic blood pressure (BP) decreased from 154 +/- 21 to 133 +/- 21 mm Hg (p = 0.008), diastolic BP from 97 +/- 13 to 77 +/- 15 mm Hg (p = 0.016), total cholesterol from 6.08 +/- 0.9 to 5.68 +/- 1.1 mmol/l (p = 0.02), LDL-chol from 3.29 +/- 1.01 to 2.96 +/- 0.3 mmol/l (p = 0.04) and apo-B lipoprotein from 1.42 +/- 0.28 to 1.15 +/- 0.34 mg/dl (p = 0.003). The oxidation of LDL improved after conversion: the initial dienic compounds decreased from 95 +/- 20 to 63 +/- 12 umol/g and the final DC from 207 +/- 56 to 107 +/- 35 umol/g. Lag-phase increased from 33 +/- 21 to 45 +/- 17 min (p < 0.05).

CONCLUSION

Tacrolimus has improved hyperlipidaemia in our cyclosporin previously treated patients and increased the resistance to oxidation of high and low-density lipoproteins.

Hepatitis C virus infection and de novo glomerular lesions in renal allografts

In the present study we examine whether hepatitis C virus (HCV) infection status influences glomerular pathologic findings in renal allografts and its effect on graft outcome. Renal allograft biopsies performed between January 1991 and June 1999 were considered. Exclusion criteria were insufficient sample, unknown HCV serological status at time of biopsy and final diagnosis of acute rejection. Light microscopy and immunofluorescence studies were performed on all biopsies. According to a predefined protocol, electron microscopy was carried out. Of 138 eligible renal allograft biopsies, 42 fulfilled at least one exclusion criterion. Of 96 biopsies selected for the study, 44 (45.8%) were from HCV-positive and 52 from HCV-negative recipients. Renal biopsy was performed 74 +/- 55 and 60 +/- 39 months after transplantation in HCV-positive and HCV-negative groups, respectively (p = 0.12). Of 44 HCV-positive biopsies, 20 (45.4%) showed membranoproliferative glomerulonephritis (MPGN) (16 type I and 4 type III). Conversely, in HCV-negative biopsies there were only three cases of MPGN (2 type I and 1 type III). De novo membranous GN (MGN) was diagnosed in 8/44 (18.2%) HCV-positive and in 4/52 (7.7%) HCV-negative cases. The prevalence of chronic transplant glomerulopathy was similar in HCV-positive and HCV-negative groups (11.4% and 11.5%, respectively). The prognosis of de novo GN (either MPGN or MGN) was worse in HCV-positive than in HCV-negative recipients (relative risk 4.89; 95% confidence interval, 1.15-20.69; p = 0.03). By multivariate analysis, HCV-positive serology infection was the only independent predictor of graft loss (relative risk 2.64; 95% confidence interval, 1.35-5.17; p = 0.005). In diagnostic renal allograft biopsies the presence of de novo immune-mediated glomerulonephritis, especially type I MPGN, is strongly associated with HCV infection and results in accelerated loss of the graft.