Isatuximab Monotherapy for Desensitization in Highly Sensitized Patients Awaiting Kidney Transplant.

SIGNIFICANCE STATEMENT: There is no standardized desensitization regimen for kidney transplant candidates. CD38, expressed by plasma cells, could be targeted for desensitization to deplete plasma cells producing alloantibodies and donor-specific antibodies. Few studies and case reports are available regarding the use of CD38 antibodies for desensitization in patients awaiting kidney transplant. This study shows that isatuximab, a CD38-targeting therapy, was well tolerated in kidney transplant candidates, with a durable decrease in anti-HLA antibodies and partial desensitization activity. The short treatment period and long follow-up of this study allowed for the understanding of the mechanism and timing for any antibody rebound. Isatuximab could be further investigated as an option for adjunct therapy to existing desensitization for patients on the kidney transplant waitlist. BACKGROUND: Patients with calculated panel reactive antibody (cPRA) ≥80.00%, particularly those with cPRA ≥99.90%, are considered highly sensitized and underserved by the Kidney Allocation System. Desensitization removes circulating reactive antibodies and/or suppresses antibody production to increase the chances of a negative crossmatch. CD38 is expressed highly on plasma cells, thus is a potential target for desensitization. METHODS: This was an open-label single-arm phase 1/2 study investigating the safety, pharmacokinetics, and preliminary efficacy of isatuximab in patients awaiting kidney transplantation. There were two cohorts, cohorts A and B, which enrolled cPRA ≥99.90% and 80.00% to <99.90%, respectively. RESULTS: Twenty-three patients (12 cohort A, 11 cohort B) received isatuximab 10 mg/kg weekly for 4 weeks then every 2 weeks for 8 weeks. Isatuximab was well tolerated with pharmacokinetic and pharmacodynamic profiles that indicated similar exposure to multiple myeloma trials. It resulted in decreases in CD38 + plasmablasts, plasma cells, and NK cells and significant reductions in HLA-specific IgG-producing memory B cells. Overall response rate, on the basis of a predefined composite desensitization end point, was 83.3% and 81.8% in cohorts A and B. Most responders had decreases in anti-HLA antibodies that were maintained for 26 weeks after the last dose. Overall, cPRA values were minimally affected, however, with only 9/23 patients (39%) having cPRA decreases to target levels. By study cutoff (median follow-up of 68 weeks), six patients received transplant offers, of which four were accepted. CONCLUSIONS: In this open-label trial, isatuximab was well tolerated and resulted in a durable decrease in anti-HLA antibodies with partial desensitization activity. CLINICAL TRIAL REGISTRATION NUMBER: NCT04294459 .

Colony stimulating factor-1 receptor drives glomerular parietal epithelial cell activation in focal segmental glomerulosclerosis.

Parietal epithelial cells (PECs) are kidney progenitor cells with similarities to a bone marrow stem cell niche. In focal segmental glomerulosclerosis (FSGS) PECs become activated and contribute to extracellular matrix deposition. Colony stimulating factor-1 (CSF-1), a hematopoietic growth factor, acts via its specific receptor, CSF-1R, and has been implicated in several glomerular diseases, although its role on PEC activation is unknown. Here, we found that CSF-1R was upregulated in PECs and podocytes in biopsies from patients with FSGS. Through in vitro studies, PECs were found to constitutively express CSF-1R. Incubation with CSF-1 induced CSF-1R upregulation and significant transcriptional regulation of genes involved in pathways associated with PEC activation. Specifically, CSF-1/CSF-1R activated the ERK1/2 signaling pathway and upregulated CD44 in PECs, while both ERK and CSF-1R inhibitors reduced CD44 expression. Functional studies showed that CSF-1 induced PEC proliferation and migration, while reducing the differentiation of PECs into podocytes. These results were validated in the Adriamycin-induced FSGS experimental mouse model. Importantly, treatment with either the CSF-1R-specific inhibitor GW2580 or Ki20227 provided a robust therapeutic effect. Thus, we provide evidence of the role of the CSF-1/CSF-1R pathway in PEC activation in FSGS, paving the way for future clinical studies investigating the therapeutic effect of CSF-1R inhibitors on patients with FSGS.

Relative survival in patients with cancer and kidney failure.

BACKGROUND AND HYPOTHESIS: The population with kidney failure is at increased risk of cancer and associated mortality. Relative survival can provide insight into the excess mortality, directly or indirectly, attributed to cancer in the population with kidney failure. METHODS: We estimated relative survival for people all ages receiving dialysis (n = 4089) and kidney transplant recipients (n = 3253) with de novo cancer, and for the general population with cancer in Australia and New Zealand (n = 3 043 166) over the years 1980-2019. The entire general population was the reference group for background mortality, adjusted for sex, age, calendar year and country. We used Poisson regression to quantify excess mortality ratios. RESULTS: Five-year relative survival for all-site cancer was markedly lower than the general population for people receiving dialysis (0.25, 95%CI:0.23-0.26) and kidney transplant recipients (0.55, 95%CI:0.53-0.57). In dialysis, excess mortality was more than double (2.16, 95%CI:2.08-2.25) that of the general population with cancer and for kidney transplant recipients 1.34 higher (95%CI:1.27-2.41). There was no difference in excess mortality from lung cancer between people with kidney failure and the general population with cancer. Comparatively, there was a significant survival deficit for people with kidney failure, compared to the general population with cancer, for melanoma, breast cancer and prostate cancers. CONCLUSION: Decreased cancer survival in kidney failure may reflect differences in multi-morbidity burden, reduced access to treatment, or greater harm from or reduced efficacy of treatments. Our findings support research aimed at investigating these hypotheses.

A prospective controlled, randomized clinical trial of kidney transplant recipients developed personalized tacrolimus dosing using model-based Bayesian Prediction.

For three decades, tacrolimus (Tac) dose adjustment in clinical practice has been calculated empirically according to the manufacturer's labeling based on a patient's body weight. Here, we developed and validated a Population pharmacokinetic (PPK) model including pharmacogenetics (cluster CYP3A4/CYP3A5), age, and hematocrit. Our study aimed to assess the clinical applicability of this PPK model in the achievement of Tac Co (therapeutic trough Tac concentration) compared to the manufacturer's labelling dosage. A prospective two-arm, randomized, clinical trial was conducted to determine Tac starting and subsequent dose adjustments in 90 kidney transplant recipients. Patients were randomized to a control group with Tac adjustment according to the manufacturer's labeling or the PPK group adjusted to reach target Co (6-10 ng/ml) after the first steady state (primary endpoint) using a Bayesian prediction model (NONMEM). A significantly higher percentage of patients from the PPK group (54.8%) compared with the control group (20.8%) achieved the therapeutic target fulfilling 30% of the established superiority margin defined. Patients receiving PPK showed significantly less intra-patient variability compared to the control group, reached the Tac Co target sooner (5 days vs 10 days), and required significantly fewer Tac dose modifications compared to the control group within 90 days following kidney transplant. No statistically significant differences occurred in clinical outcomes. Thus, PPK-based Tac dosing offers significant superiority for starting Tac prescription over classical labeling-based dosing according to the body weight, which may optimize Tac-based therapy in the first days following transplantation.

Post-transplant diabetes mellitus and renal cell cancer after renal transplantation.

BACKGROUND: Diabetes is a risk factor for cancer in the general population. However, few data are available on the association between post-transplant diabetes mellitus (PTDM) and cancer after transplantation. METHODS: We analyzed this issue in a Spanish cohort of patients without diabetes before transplantation. PTDM was diagnosed with consensus criteria at 12 months after transplantation and 12 months before the diagnosis of cancer. The association between PTDM and cancer (overall and specific types) was evaluated with regression analysis. RESULTS: During a follow-up of 12 years (interquartile range 8-14), 85 cases of 603 developed cancer (829/100 000/year) and 164 (27%) PTDM. The most frequent cancers were renal cell cancer (RCC) n = 15, 146/cases/100 000/year), lung (n = 12, 117/cases/100 000/year), colon (n = 9, 88/cases/100 000/year) and prostate (n = 9, 88/cases/100 000/year). In logistic regression, PTDM was not associated with cancer. Eight of the 164 patients with PTDM (4.9%) vs 7 of the 439 without PTDM developed RCC (1.6%) (P = .027). In multivariate analysis, PTDM was independently associated with RCC [odds ratio (OR) 2.92, confidence interval (CI) 1.03-8.27], adjusting for smoking (OR 4.020, 95% CI 1.34-12.02) and other covariates. PTDM was not associated with other types of cancer. CONCLUSIONS: Patients with PTDM must be considered a population at risk for RCC and accordingly, the subject of active surveillance.

Molecular Mechanisms of Kidney Injury and Repair.

Chronic kidney disease (CKD) will become the fifth global cause of death by 2040, thus emphasizing the need to better understand the molecular mechanisms of damage and regeneration in the kidney. CKD predisposes to acute kidney injury (AKI) which, in turn, promotes CKD progression. This implies that CKD or the AKI-to-CKD transition are associated with dysfunctional kidney repair mechanisms. Current therapeutic options slow CKD progression but fail to treat or accelerate recovery from AKI and are unable to promote kidney regeneration. Unraveling the cellular and molecular mechanisms involved in kidney injury and repair, including the failure of this process, may provide novel biomarkers and therapeutic tools. We now review the contribution of different molecular and cellular events to the AKI-to-CKD transition, focusing on the role of macrophages in kidney injury, the different forms of regulated cell death and necroinflammation, cellular senescence and the senescence-associated secretory phenotype (SAPS), polyploidization, and podocyte injury and activation of parietal epithelial cells. Next, we discuss key contributors to repair of kidney injury and opportunities for their therapeutic manipulation, with a focus on resident renal progenitor cells, stem cells and their reparative secretome, certain macrophage subphenotypes within the M2 phenotype and senescent cell clearance.

SARS-CoV-2-specific serological and functional T cell immune responses during acute and early COVID-19 convalescence in solid organ transplant patients.

The description of protective humoral and T cell immune responses specific against SARS-CoV-2 has been reported among immunocompetent (IC) individuals developing COVID-19 infection. However, its characterization and determinants of poorer outcomes among the at-risk solid organ transplant (SOT) patient population have not been thoroughly investigated. Cytokine-producing T cell responses, such as IFN-γ, IL-2, IFN-γ/IL-2, IL-6, IL-21, and IL-5, against main immunogenic SARS-CoV-2 antigens and IgM/IgG serological immunity were tracked in SOT (n = 28) during acute infection and at two consecutive time points over the following 40 days of convalescence and were compared to matched IC (n = 16) patients admitted with similar moderate/severe COVID-19. We describe the development of a robust serological and functional T cell immune responses against SARS-CoV-2 among SOT patients, similar to IC patients during early convalescence. However, at the infection onset, SOT displayed lower IgG seroconversion rates (77% vs. 100%; p = .044), despite no differences on IgG titers, and a trend toward decreased SARS-CoV-2-reactive T cell frequencies, especially against the membrane protein (7 [0-34] vs. 113 [15-245], p = .011, 2 [0-9] vs. 45 [5-74], p = .009, and 0 [0-2] vs. 13 [1-24], p = .020, IFN-γ, IL-2, and IFN-γ/IL-2 spots, respectively). In summary, our data suggest that despite a certain initial delay, SOT population achieve comparable functional immune responses than the general population after moderate/severe COVID-19.

Adoption of a novel smart mobile-health application technology to track chronic immunosuppression adherence in solid organ transplantation: Results of a prospective, observational, multicentre, pilot study.

BACKGROUND: Low adherence to chronic immunosuppression is associated with suboptimal transplantation outcomes. Mobile-health technology is a promising tool to monitor medication adherence, but data on patient engagement to these tools are lacking. METHODS: Prospective, observational, multicenter, 2-phase trial in kidney and liver transplant recipients, investigating the degree of engagement to TrackYourMed® (TYM), a novel m-Health technology with a QR code-scan app to track immunosuppression adherence and its association with drug monitoring. RESULTS: Out of 204 consecutive transplant patients, 90 patients were eligible to participate. 61 (68%) used TYM regularly, 21 (23%) never or barely used it, 5 (5.5%) were irregular users, and 3 (3.3%) were lost to follow-up. 6-month total correct intakes (CIN) ranged between 69%-76%, 12%-19% intakes were out-of-time (OUT), and 9%-12% were missed (MIS). Notably, a rate of intakes out of the scheduled time higher than 20% in the 6 days prior to blood immunosuppressant trough levels was associated with a higher intra-patient variability (17 IQR 13-21% vs. 29 IQR 23%-36%, p = .001), and with a higher dose-adjustment (p < .001). At 1 year, 53(59%) patients were still active users of TYM. CONCLUSIONS: Implementing m-Health technologies promoting immunosuppression adherence may be useful for a relevant number of transplant patients and help transplant physicians identifying erratic immunosuppression adherence.

Deciphering transplant outcomes of expanded kidney allografts donated after controlled circulatory death in the current transplant era. A call for caution.

Outcomes of kidney transplantation (KT) after controlled circulatory death (cDCD) with highly expanded criteria donors (ECD) and recipients have not been thoroughly evaluated. We analyzed in a multicenter cohort of 1161 consecutive KT, granular baseline donor and recipient factors predicting transplant outcomes, selected by bootstrapping and Cox proportional hazards, and were validated in a contemporaneous European KT cohort (n = 1585). 74.3% were DBD and 25.7% cDCD-KT. ECD-KT showed the poorest graft survival rates, irrespective of cDCD or DBD (log-rank < 0.001). Besides standard ECD classification, dialysis vintage, older age, and previous cardiovascular recipient events together with low class-II-HLA match, long cold ischemia time and combining a diabetic donor with a cDCD predicted graft loss (C-Index 0.715, 95% CI 0.675-0.755). External validation showed good prediction accuracy (C-Index 0.697, 95%CI 0.643-0.741). Recipient older age, male gender, dialysis vintage, previous cardiovascular events, and receiving a cDCD independently predicted patient death. Benefit/risk assessment of undergoing KT was compared with concurrent waitlisted candidates, and despite the fact that undergoing KT outperformed remaining waitlisted, remarkably high mortality rates were predicted if KT was undertaken under the worst risk-prediction model. Strategies to increase the donor pool, including cDCD transplants with highly expanded donor and recipient candidates, should be performed with caution.

Functional immune monitoring of BK Virus and donor-specific T-cell effector immune responses to guide treatment decision-making after kidney transplantation; an illustrative case report and literature review.

Differential diagnosis between Polyoma virus associated-nephropathy (PVAN) and T-cell mediated rejection (TCMR) might be challenging, as respective treatment approaches are totally opposite. Here we report the illustrative case of a kidney transplant recipient with PVAN who developed a persistent acute TCMR after full abrogation of viral infection through immunosuppression modulation. By simultaneous functional immune monitoring of BKV and donor-specific T-cell responses using IFN-γELISPOT assay, we retrospectively demonstrated the predominant effector mechanisms responsible of allograft injury and thus, potential guidance for treatment decision-making. Furthermore, the evidence of an efficient T-cell alloimmunity abrogation accompanied by a sustained anti-viral response after sirolimus addition, promotes the potential benefit of converting patients to an mTOR-based immunosuppression in case of PVAN.

Tuberculosis prevention in patients undergoing kidney transplantation: A nurse-led program for screening and treatment.

BACKGROUND: Systematic screening for, and treatment of, latent tuberculosis (TB) infection is recommended prior to kidney transplant. However, little is known about patient compliance with, or the safety profile of, preventive therapies used in clinical practice. METHODS: This was a retrospective observational study of patients who were eligible for kidney transplant and were evaluated for TB infection between January 2013 and June 2019 at the TB clinic of a tertiary care teaching hospital. All patient data were registered prospectively as part of our nurse-led program before kidney transplant. We assessed completion rates, tolerance with therapy, development of TB, and associated workload. RESULTS: In total, 1568 patients were referred to our TB clinic for evaluation. Preventive therapy was given to 385 patients and completed by 340 (88.3%). Of these, 89 (23.1%) experienced some intolerance, with 27 requiring full discontinuation. After a median follow-up of 45 months (1426 patient-years), 206 (53.5%) of the treated patients received a kidney transplant; only one patient, who failed to complete treatment, developed post-transplant TB (7.01 cases per 10 000 patient-years; 95% confidence interval, 0.35-34.59). Extra nurse or medical visits were required by 268 (69.6%) patients. CONCLUSION: Despite the complexity and workload generated by patients with ESRD awaiting kidney transplant, preventive therapy for TB is effective in most cases. Our experience provides important evidence on the feasibility of preventive therapy for TB before kidney transplant when delivered as part of a comprehensive nurse-led program.

Cellular Immunity to Predict the Risk of Cytomegalovirus Infection in Kidney Transplantation: A Prospective, Interventional, Multicenter Clinical Trial.

BACKGROUND: Improving cytomegalovirus (CMV) immune-risk stratification in kidney transplantation is highly needed to establish guided preventive strategies. METHODS: This prospective, interventional, multicenter clinical trial assessed the value of monitoring pretransplant CMV-specific cell-mediated immunity (CMI) using an interferon-γ release assay to predict CMV infection in kidney transplantation. One hundred sixty donor/recipient CMV-seropositive (D+/R+) patients, stratified by their baseline CMV (immediate-early protein 1)-specific CMI risk, were randomized to receive either preemptive or 3-month antiviral prophylaxis. Also, 15-day posttransplant CMI risk stratification and CMI specific to the 65 kDa phosphoprotein (pp65) CMV antigen were investigated. Immunosuppression consisted of basiliximab, tacrolimus, mycophenolate mofetil, and corticosteroids in 80% of patients, whereas 20% received thymoglobulin induction therapy. RESULTS: Patients at high risk for CMV based on pretransplant CMI developed significantly higher CMV infection rates than those deemed to be at low risk with both preemptive (73.3% vs 44.4%; odds ratio [OR], 3.44 [95% confidence interval {CI}, 1.30-9.08]) and prophylaxis (33.3% vs 4.1%; OR, 11.75 [95% CI, 2.31-59.71]) approaches. The predictive capacity for CMV-specific CMI was only found in basiliximab-treated patients for both preemptive and prophylaxis therapy. Fifteen-day CMI risk stratification better predicted CMV infection (81.3% vs 9.1%; OR, 43.33 [95% CI, 7.89-237.96]). CONCLUSIONS: Pretransplant CMV-specific CMI identifies D+/R+ kidney recipients at high risk of developing CMV infection if not receiving T-cell-depleting antibodies. Monitoring CMV-specific CMI soon after transplantation further defines the CMV infection prediction risk. Monitoring CMV-specific CMI may guide decision making regarding the type of CMV preventive strategy in kidney transplantation. CLINICAL TRIALS REGISTRATION: NCT02550639.

Clinical characteristics and risk factors for severe COVID-19 in hospitalized kidney transplant recipients: A multicentric cohort study.

Kidney transplant recipients might be at higher risk for severe coronavirus disease 2019 (COVID-19). However, risk factors for relevant outcomes remain uncertain in this population. This is a multicentric kidney transplant cohort including 104 hospitalized patients between March 4 and April 17, 2020. Risk factors for death and acute respiratory distress syndrome (ARDS) were investigated, and clinical and laboratory data were analyzed. The mean age was 60 years. Forty-seven patients (54.8%) developed ARDS. Obesity was associated to ARDS development (OR 2.63; P = .04). Significant age differences were not found among patients developing and not developing ARDS (61.3 vs 57.8 years, P = .16). Seventy-six (73%) patients were discharged, and 28 (27%) died. Death was more common among the elderly (55 and 70.8 years, P < .001) and those with preexisting pulmonary disease (OR 2.89, P = .009). At admission, higher baseline lactate dehydrogenase (257 vs 358 IU/mL, P = .001) or ARDS conferred higher risk of death (HR 2.09, P = .044). In our cohort, ARDS was equally present among young and old kidney recipients. However, the elderly might be at higher risk of death, along with those showing higher baseline LDH at admission.

Long-term results of a randomized study comparing parathyroidectomy with cinacalcet for treating tertiary hyperparathyroidism.

Tertiary hyperparathyroidism is a common cause of hypercalcemia after kidney transplantation (KT) and has been associated with renal dysfunction, bone mineral density loss, and increased risk of fracture and cardiovascular events. In a previous 12-month clinical trial, we demonstrated that subtotal parathyroidectomy was more effective than cinacalcet for controlling hypercalcemia. In the current study, we retrospectively evaluate whether this effect is maintained after 5 years of follow-up. In total, 24 patients had data available at 5 years, 13 in the cinacalcet group and 11 in the parathyroidectomy group. At 5 years, 7 of 11 patients (64%) in the parathyroidectomy group and 6 of 13 patients (46%) in the cinacalcet group (P = .44) showed normocalcemia. However, recurrence of hypercalcemia was only observed in the cinacalcet group (P = .016). Subtotal parathyroidectomy retained a greater reduction in intact parathyroid hormone (iPTH) compared with cinacalcet group. No differences were observed in kidney function and incidence of fragility fractures between both groups. Cinacalcet was discontinued in 5 out of 13 patients. In conclusion, in kidney transplant patients with tertiary hyperparathyroidism recurrence of hypercalcemia after 5-year follow-up is more frequent in cinacalcet than after subtotal parathyroidectomy.

Chronic Kidney Disease-Associated Inflammation Increases the Risks of Acute Kidney Injury and Mortality after Cardiac Surgery.

Cardiovascular mortality increases with decreasing renal function although the cause is yet unknown. Here, we have investigated whether low chronic inflammation in chronic kidney diseases (CKD) could contribute to increased risk for coronary artery diseases (CAD). Thus, a prospective case-control study was conducted in patients with CAD and CKD undergoing coronary artery bypass graft surgery with the aim of detecting differences in cardiovascular outcomes, epicardial adipose tissue volume, and inflammatory marker activity associated with renal dysfunction. Expression of membrane CD14 and CD16, inflammatory cytokines and chemokines, mitogen-activated protein (MAP) kinases and hsa-miR-30a-5p were analyzed in peripheral blood mononuclear cells (PBMCs). Epicardial fat volume and tissue inflammation in perivascular adipose tissue and in the aorta were also studied. In the present study, 151 patients were included, 110 with CAD (51 with CKD) and 41 nonCAD controls (15 with CKD). CKD increased the risk of cardiac surgery-associated acute kidney injury (CSA-AKI) as well as the 30-day mortality after cardiac surgery. Higher counts of CD14++CD16+ monocytes were associated with vascular inflammation, with an increased expression of IL1ß, and with CKD in CAD patients. Expression of hsa-miR-30a-5p was correlated with hypertension. We conclude that CKD patients show an increased risk of CSA-AKI and mortality after cardiovascular surgery, associated with the expansion of the CD14++CD16+ subset of proinflammatory monocytes and with IL1ß expression. We propose that inflammation associated with CKD may contribute to atherosclerosis (ATH) pathogenesis.

Integrated miRNA/mRNA Counter-Expression Analysis Highlights Oxidative Stress-Related Genes CCR7 and FOXO1 as Blood Markers of Coronary Arterial Disease.

Our interest in the mechanisms of atherosclerosis progression (ATHp) has led to the recent identification of 13 miRNAs and 1285 mRNAs whose expression was altered during ATHp. Here, we deepen the functional relationship among these 13 miRNAs and genes associated to oxidative stress, a crucial step in the onset and progression of vascular disease. We first compiled a list of genes associated to the response to oxidative stress (Oxstress genes) by performing a reverse Gene Ontology analysis (rGO, from the GO terms to the genes) with the GO terms GO0006979, GO1902882, GO1902883 and GO1902884, which included a total of 417 unique Oxstress genes. Next, we identified 108 putative targets of the 13 miRNAs among these unique Oxstress genes, which were validated by an integrated miRNA/mRNA counter-expression analysis with the 1285 mRNAs that yielded 14 genes, Map2k1, Mapk1, Mapk9, Dapk1, Atp2a2, Gata4, Fos, Egfr, Foxo1, Ccr7, Vkorc1l1, Rnf7, Kcnh3, and Mgat3. GO enrichment analysis and a protein-protein-interaction network analysis (PPI) identified most of the validated Oxstress transcripts as components of signaling pathways, highlighting a role for MAP signaling in ATHp. Lastly, expression of these Oxstress transcripts was measured in PBMCs from patients suffering severe coronary artery disease, a serious consequence of ATHp. This allowed the identification of FOXO1 and CCR7 as blood markers downregulated in CAD. These results are discussed in the context of the interaction of the Oxstress transcripts with the ATHp-associated miRNAs.

Exploring macrophage cell therapy on Diabetic Kidney Disease.

Alternatively activated macrophages (M2) have regenerative properties and shown promise as cell therapy in chronic kidney disease. However, M2 plasticity is one of the major hurdles to overcome. Our previous studies showed that genetically modified macrophages stabilized by neutrophil gelatinase-associated lipocalin (NGAL) were able to preserve their M2 phenotype. Nowadays, little is known about M2 macrophage effects in diabetic kidney disease (DKD). The aim of the study was to investigate the therapeutic effect of both bone marrow-derived M2 (BM-фM2) and ф-NGAL macrophages in the db/db mice. Seventeen-week-old mice with established DKD were divided into five treatment groups with their controls: D+BM-фM2; D+ф-BM; D+ф-NGAL; D+ф-RAW; D+SHAM and non-diabetic (ND) (db/- and C57bl/6J) animals. We infused 1 × 106 macrophages twice, at baseline and 2 weeks thereafter. BM-фM2 did not show any therapeutic effect whereas ф-NGAL significantly reduced albuminuria and renal fibrosis. The ф-NGAL therapy increased the anti-inflammatory IL-10 and reduced some pro-inflammatory cytokines, reduced the proportion of M1 glomerular macrophages and podocyte loss and was associated with a significant decrease of renal TGF-ß1. Overall, our study provides evidence that ф-NGAL macrophage cell therapy has a therapeutic effect on DKD probably by modulation of the renal inflammatory response caused by the diabetic milieu.

Value of monitoring circulating donor-reactive memory B cells to characterize antibody-mediated rejection after kidney transplantation.

Antibody-mediated rejection (ABMR) is defined by specific histopathological lesions and evidence of circulating donor-specific antibodies (DSA). Although DSA are not always detectable, monitoring donor-reactive memory B cells (mBC) could identify patients at risk of developing ABMR. Peripheral donor-reactive mBC using a novel HLA B cell ELISpot assay, serum DSA, and numbers of different B cell subsets were assessed in 175 consecutive kidney transplants undergoing either for-cause or 6- and 24-month surveillance biopsies for their association with main histological lesions of ABMR and impact on allograft outcome. In 85 incident for-cause biopsies, high frequencies of donor-reactive mBC were detected in all 16 (100%) acute ABMR/DSA+ and most chronic ABMR, with or without DSA (24/30[80%] and 21/29[72.4%], respectively). In a longitudinal cohort of 90 nonsensitized patients, a progressively higher expansion of donor-reactive mBC than de novo DSA was observed at 6 and 24 months (8.8% vs 7.7% and 15.5% vs 11.1%, respectively) and accurately identified patients with ongoing subclinical ABMR (area under the curve = 0.917 and area under the curve = 0.809, respectively). An unsupervised hierarchical cluster analysis revealed a strong association between donor-reactive mBC with main fundamental allograft lesions associated with ABMR and conferred a significant deleterious impact on graft outcome. Monitoring donor-reactive mBC may be useful to further characterize humoral rejection after kidney transplantation.

Two-year outcomes in de novo renal transplant recipients receiving everolimus-facilitated calcineurin inhibitor reduction regimen from the TRANSFORM study.

TRANSFORM (TRANSplant eFficacy and safety Outcomes with an eveRolimus-based regiMen) was a 24-month, prospective, open-label trial in 2037 de novo renal transplant recipients randomized (1:1) within 24 hours of transplantation to receive everolimus (EVR) with reduced-exposure calcineurin inhibitor (EVR + rCNI) or mycophenolate with standard-exposure CNI. Consistent with previously reported 12-month findings, noninferiority of the EVR + rCNI regimen for the primary endpoint of treated biopsy-proven acute rejection (tBPAR) or estimated glomerular filtration rate (eGFR) <50 mL/min per 1.73 m2 was achieved at month 24 (47.9% vs 43.7%; difference = 4.2%; 95% confidence interval = -0.3, 8.7; P = .006). Mean eGFR was stable up to month 24 (52.6 vs 54.9 mL/min per 1.73 m2 ) in both arms. The incidence of de novo donor-specific antibodies (dnDSA) was lower in the EVR + rCNI arm (12.3% vs 17.6%) among on-treatment patients. Although discontinuation rates due to adverse events were higher with EVR + rCNI (27.2% vs 15.0%), rates of cytomegalovirus (2.8% vs 13.5%) and BK virus (5.8% vs 10.3%) infections were lower. Cytomegalovirus infection rates were significantly lower with EVR + rCNI even in the D+/R- high-risk group (P < .0001). In conclusion, the EVR + rCNI regimen offers comparable efficacy and graft function with low tBPAR and dnDSA rates and significantly lower incidence of viral infections relative to standard-of-care up to 24 months. Clinicaltrials.gov number: NCT01950819.

Antioxidant and Anti-Inflammatory Strategies Based on the Potentiation of Glutathione Peroxidase Activity Prevent Endothelial Dysfunction in Chronic Kidney Disease.

BACKGROUND/AIMS: Accelerated atherosclerosis in chronic kidney disease (CKD) is preceded by endothelial dysfunction (ED), which exhibits a proinflammatory and prothrombotic phenotype and enhanced oxidative stress. In this study, the effect of several compounds with anti-inflammatory and/or antioxidant properties on uremia-induced endothelial dysfunction has been evaluated in an in vitro model. METHODS: Endothelial cells (ECs) were exposed to sera from uremic patients in the absence and presence of the flavonoids apigenin, genistein and quercetin, the antioxidant enzyme mimetics (AEM) ebselen (glutathione peroxidase mimetic), EUK-134 and EUK-118 (both superoxide dismutase mimetics), and the pharmacological drug N-acetylcysteine (NAC). We explored changes in the expression of adhesion receptors on the cell surface, by immunofluorescence, the production of radical oxygen species (ROS), by fluorescence detection, and the activation of signaling proteins related to inflammation, by both a phosphospecific antibody cell-based ELISA and immunoblotting techniques. RESULTS: Uremic media induced a significantly increased expression of ICAM-1, overproduction of radical oxygen species (ROS) and activation of p38 mitogen activated protein kinase (p38MAPK) and Nuclear Factor kB (NFkB) in ECs. Quercetin, the AEM and NAC showed a significant inhibitory effect on both ICAM-1 expression and ROS generation (p<0.05). All the compounds reduced p38MAPK activation, but only the AEM, especially ebselen, and NAC, both potentiating the glutathione peroxidase pathway, also inhibited NFkB activation. These two compounds were capable of increasing endothelial glutathione levels, especially in response to uremia. CONCLUSION: Our results indicate that the potentiation of the antioxidant pathways can be an effective strategy to improve endothelial dysfunction in uremia and a potential target to reduce the cardiovascular risk in this population.