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.

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.

Contribution of Population Pharmacokinetics to Dose Optimization of Ganciclovir-Valganciclovir in Solid-Organ Transplant Patients.

Treatment of solid-organ transplant (SOT) patients with ganciclovir (GCV)-valganciclovir (VGCV) according to the manufacturer's recommendations may result in over- or underexposure. Bayesian prediction based on a population pharmacokinetics model may optimize GCV-VGCV dosing, achieving the area under the curve (AUC) therapeutic target. We conducted a two-arm, randomized, open-label, 40% superiority trial in adult SOT patients receiving GCV-VGCV as prophylaxis or treatment of cytomegalovirus infection. Group A was treated according to the manufacturer's recommendations. For group B, the dosing was adjusted based on target exposures using a Bayesian prediction model (NONMEM). Fifty-three patients were recruited (27 in group A and 26 in group B). About 88.6% of patients in group B and 22.2% in group A reached target AUC, achieving the 40% superiority margin (P< 0.001; 95% confidence interval [CI] difference, 47 to 86%). The time to reach target AUC was significantly longer in group A than in group B (55.9 ± 8.2 versus 15.8 ± 2.3 days,P< 0.001). A shorter time to viral clearance was observed in group B than in group A (12.5 versus 17.6 days;P= 0.125). The incidences of relapse (group A, 66.67%, and group B, 9.01%) and late-onset infection (group A, 36.7%, and group B, 7.7%) were higher in group A. Neutropenia and anemia were related to GCV overexposure. GCV-VCGV dose adjustment based on a population pharmacokinetics Bayesian prediction model optimizes GCV-VGCV exposure. (This study has been registered at ClinicalTrials.gov under registration no. NCT01446445.).

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.

Novel once-daily extended-release tacrolimus (LCPT) versus twice-daily tacrolimus in de novo kidney transplants: one-year results of Phase III, double-blind, randomized trial.

This Phase III randomized trial examined efficacy and safety of a novel once-daily extended-release tacrolimus formulation (LCP-Tacro [LCPT]) versus twice-daily tacrolimus in de novo kidney transplantation. Primary efficacy end point was proportion of patients with treatment failure (death, graft failure, biopsy-proven acute rejection or lost to follow-up) within 12 months. Starting doses were, LCPT: 0.17 mg/kg/day and tacrolimus twice-daily: 0.1 mg/kg/day; 543 patients were randomized, LCPT: n = 268; tacrolimus twice-daily: n = 275. At 12 months treatment failure was LCPT: 18.3% and tacrolimus twice-daily: 19.6%; the upper 95% CI of the treatment difference was +5.27%, below the predefined +10% noninferiority criteria. There were no significant differences in the incidence of individual efficacy events or adverse events. Target tacrolimus trough levels were more rapidly achieved in the LCPT group. Following initial dose, 36.6% of patients in the LCPT group had rapidly attained trough levels within 6-11 ng/mL versus 18.5% of tacrolimus twice-daily patients; majority of tacrolimus twice-daily patients (74.7%) had troughs <6 ng/mL compared with 33.5% in the LCPT group. Overall, cumulative study dose was 14% lower for LCPT. Results suggest that use of once-daily LCPT in de novo kidney transplantation is efficacious and safe. Lower LCPT dose reflects the improved absorption provided by the novel formulation.

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.

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.

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.

Three-year outcomes from BENEFIT-EXT: a phase III study of belatacept versus cyclosporine in recipients of extended criteria donor kidneys.

Recipients of extended-criteria donor (ECD) kidneys have poorer long-term outcomes compared to standard-criteria donor kidney recipients. We report 3-year outcomes from a randomized, phase III study in recipients of de novo ECD kidneys (n = 543) assigned (1:1:1) to either a more intensive (MI) or less intensive (LI) belatacept regimen, or cyclosporine. Three hundred twenty-three patients completed treatment by year 3. Patient survival with a functioning graft was comparable between groups (80% in MI, 82% in LI, 80% in cyclosporine). Mean calculated GFR (cGFR) was 11 mL/min higher in belatacept-treated versus cyclosporine-treated patients (42.7 in MI, 42.2 in LI, 31.5 mL/min in cyclosporine). More cyclosporine-treated patients (44%) progressed to GFR <30 mL/min (chronic kidney disease [CKD] stage 4/5) than belatacept-treated patients (27-30%). Acute rejection rates were similar between groups. Posttransplant lymphoproliferative disorder (PTLD) occurrence was higher in belatacept-treated patients (two in MI, three in LI), most of which occurred during the first 18 months; four additional cases (3 in LI, 1 in cyclosporine) occurred after 3 years. Tuberculosis was reported in two MI, four LI and no cyclosporine patients. In conclusion, at 3 years after transplantation, immunosuppression with belatacept resulted in similar patient survival, graft survival and acute rejection, with better renal function compared with cyclosporine. As previously reported, PTLD and tuberculosis were the principal safety findings associated with belatacept in this study population.

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.

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.

Sotrastaurin, a novel small molecule inhibiting protein kinase C: first clinical results in renal-transplant recipients.

Sotrastaurin, a novel protein-kinase-C inhibitor, blocks early T-cell activation. In this 12-month, Phase II study, de novo renal-transplant patients were randomized to sotrastaurin (200 mg b.i.d.) + standard-exposure tacrolimus (SET) or reduced-exposure tacrolimus (RET) (SET: n = 76; RET: n = 66), or control (SET + mycophenolic acid [MPA, 720 mg b.i.d.]; n = 74). In both sotrastaurin groups, patients were converted from tacrolimus to MPA after Month 3, achieving calcineurin inhibitor-free immunosuppression. The primary endpoint was composite efficacy failure (treated biopsy-proven acute rejection, graft loss, death or loss to follow-up). The key secondary endpoint was glomerular filtration rate (GFR). Composite efficacy failure rates were: 4.1%, 5.4% and 1.5% at Month 3 (preconversion) and 7.8%, 44.8% and 34.1% at study end in the control, sotrastaurin + SET and sotrastaurin + RET groups, respectively; these results led to premature study discontinuation. Median GFR at Month 6 was: 57.0, 53.0 and 60.0 mL/min/1.73 m(2), respectively. Study-drug discontinuations due to adverse events occurred in 16.2%, 18.4% and 12.1%, respectively. Leukopenia and neutropenia occurred more frequently preconversion in control versus sotrastaurin groups: 13.7%, 5.6%, and 4.6%; and 11.1%, 4.3% and 3.1%, respectively. The initial sotrastaurin + tacrolimus regimen was efficacious and well tolerated but the postconversion sotrastaurin + MPA regimen showed inadequate efficacy. Longer-term evaluation of sotrastaurin + tacrolimus is warranted.

Sequential treatment of cytomegalovirus infection or disease with a short course of intravenous ganciclovir followed by oral valganciclovir: efficacy, safety, and pharmacokinetics.

Oral (p.o.) or intravenous (IV) ganciclovir (GCV) has been the first-line agent for prevention and treatment of cytomegalovirus (CMV) infection and disease in solid organ transplantation (SOT). The introduction of p.o. valganciclovir, with higher bioavailability than p.o. GCV, has proven to be a suitable approach toward outpatient p.o. therapy for CMV infection/disease. The present single-arm, exploratory pilot trial performed with 21 patients investigates the efficacy and safety of a short therapeutic course (21 days) based on an initial IV treatment with GCV (5 mg/kg twice daily, for 5 days) followed by p.o. valganciclovir (900 mg twice daily, for 16 days) for CMV infection/disease in SOT patients. In all cases, doses were adjusted for renal function. Moreover, the study allowed comparison of exposure to GCV after p.o. valganciclovir with respect to IV GCV in the same patients. Response to treatment was monitored until day 180. Viral load eradication was achieved in 66.7% of patients, on day 21. Although not statistically significant, a trend was seen toward increased persistence of viral load on day 21 for patients with donor positive/recipient negative CMV serostatus or receiving either anti-rejection therapy or polyclonal anti-thymocyte globulin. CMV clinical infection recurred in 14.3% of patients, with higher recurrence rates in patients with risk factors for persistence of viremia. Exposures to GCV after using IV GCV or p.o. valganciclovir showed comparable values (P=0.054). This short course, combining initial IV GCV and subsequent p.o. valganciclovir, may provide effective exposure and therapeutic response in the treatment of CMV infection in SOT patients with adequate drug exposure and with the additional potential benefit of shortening the length of hospital stay, which may result in cost reduction and improved patient comfort.

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.

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.

Hypoxia stimulus: An adaptive immune response during dendritic cell maturation.

The 'injury hypothesis' in organ transplantation suggests that ischemia-reperfusion injury is involved in the adaptative alloimmune response. We previously found that a strong immune/inflammatory response was induced by ischemia during kidney transplantation in rats. We show here that immature dendritic cells (DCs) undergo hypoxia-mediated differentiation comparable to allogeneic stimulation. Hypoxia-differentiated DCs overexpress hypoxia inducible factor-1alpha (HIF-1alpha) and its downstream target genes, such as vascular endothelial growth factor or glucose transporter-1. Rapamycin attenuated DC differentiation, HIF-1alpha expression, and its target gene expression in a dose-dependent manner along with downregulated interleukin-10 secretion. Coculture of hypoxia-differentiated DCs with CD3 lymphocytes induced proliferation of lymphocytes, a process also neutralized by rapamycin. Furthermore, in vivo examination of ischemia-reperfusion-injured mouse kidneys showed a clear maturation of resident DCs that was blunted by rapamycin pretreatment. Our results suggest that hypoxia is a central part of the 'injury hypothesis' triggering DC differentiation under hypoxic conditions. Rapamycin attenuates the hypoxic immune-inflammatory response through inhibition of the HIF-1alpha pathway.