Assessment and management of heart failure in patients with chronic kidney disease.

Heart failure (HF) and chronic kidney disease (CKD) are two pathological conditions with a high prevalence in the general population. When they coexist in the same patient, a strict interplay between them is observed, such that patients affected require a clinical multidisciplinary and personalized management. The diagnosis of HF and CKD relies on signs and symptoms of the patient but several additional tools, such as blood-based biomarkers and imaging techniques, are needed to clarify and discriminate the main characteristics of these diseases. Improved survival due to new recommended drugs in HF has increasingly challenged physicians to manage patients with multiple diseases, especially in case of CKD. However, the safe administration of these drugs in patients with HF and CKD is often challenging. Knowing up to which values ​​of creatinine or renal clearance each drug can be administered is fundamental. With this review we sought to give an insight on this sizable and complex topic, in order to get clearer ideas and a more precise reference about the diagnostic assessment and therapeutic management of HF and CKD.

COVID-19: The Dysregulated Response to Infection - Why Consider Polymethylmethacrylate Membrane in Hemodialysis Patients?

Since SARS-CoV-2 spread through China at the end of 2019, COVID-19 has been probably the most difficult challenge in the last decades for healthcare systems all around the world, still representing a danger for fragile patients with different comorbidities. Chronic dialysis patients affected by COVID-19 experienced severe disease with a higher mortality rate compared to the general population. Morbidity and mortality of this severe acute respiratory syndrome depend on both acute respiratory failure and systemic immunological involvement with consequent inflammation-mediated injury. Indeed, the most important determining factor of COVID-19 severity is the strength of the so-called "cytokine storm" associated with SARS-CoV-2 infection. Therefore, this severe infection varies clinically from an asymptomatic condition to a generalized and violent inflammatory response and acute respiratory distress syndrome, with consequent pulmonary interstitial edema and a high risk of multi-organ failure. The use of extracorporeal therapies targeting cytokine clearance to improve patients' outcomes has been widely debated, especially in end-stage kidney disease's patients on maintenance dialysis or in individuals affected by acute kidney injury admitted to intensive care units. Different studies were conducted to demonstrate how specific dialyzers could decrease the COVID-19 inflammatory state. The aim of this narrative review was to summarize main studies about this topic, focusing primarily on the role of polymethylmethacrylate dialyzer and underlining pros and cons of this sorbent.

Updates on C3 Glomerulopathy in Kidney Transplantation: Pathogenesis and Treatment Options.

C3 glomerulopathy is a rare disease, characterized by an abnormal activation of the complement's alternative pathway that leads to the accumulation of the C3 component in the kidney. The disease recurs in more than half of kidney transplant recipients, with a significant impact on graft survival. Recurrence of the primary disease represents the second cause of graft loss after organ rejection. In C3 glomerulopathy, there are several risk factors which can promote a recurrence during transplantation, such as delayed graft function, infection and monoclonal gammopathy. All these events can trigger the alternative complement pathway. In this review, we summarize the impact of C3 glomerulopathy on kidney grafts and present the latest treatment options. The most widely used treatments for the disease include corticosteroids and mycophenolate mofetil, which are already used chronically by kidney transplant recipients; thus, additional treatments for C3 glomerulopathy are required. Currently, several studies using anti-complement drugs (i.e., eculizumab, Ravalizumab, avacopan) for C3 glomerulopathy in kidney transplant patients are ongoing with encouraging results.

Eradication of HCV by direct antiviral agents restores mitochondrial function and energy homeostasis in peripheral blood mononuclear cells.

Hepatitis C virus (HCV) adopts several immune evasion mechanisms such as interfering with innate immunity or promoting T-cell exhaustion. However, the recent direct-antiviral agents (DAAs) rapidly eliminate the virus, and the repercussions in terms of immune system balance are unknown. Here we compared the PBMCs transcriptomic profile of patients with HCV chronic infection at baseline (T0) and 12 weeks after the end of the therapy (SVR12) with DAAs. 3862 genes were differently modulated, identifying oxidative phosphorylation as the top canonical pathway differentially activated. Therefore, we dissected PBMCs bioenergetic profile by analyzing mitochondrial respiration and glycolysis at 4 timepoints: T0, 4 weeks of therapy, end of therapy (EoT), and SVR12. Maximal and reserve respiratory capacity considerably increased at EoT, persisting until SVR12. Notably, over time a significant increase was observed in respiratory chain (RC) complexes protein levels and the enzymatic activity of complexes I, II, and IV. Mitochondrial-DNA integrity improved over time, and the expression of mitochondrial biogenesis key regulators such as TFAM, Nrf-1, and PPARGC1A significantly increased at SVR12; hence, RC complexes synthesis and mitochondrial respiration were supported after treatment. HCV clearance with DAAS profoundly changed PBMCs bioenergetic profile, suggesting the immunometabolism study as a new approach to the understanding of viral immune evasion mechanisms and host adaptations during infections and therapies.

Risk of end-stage kidney disease in kidney transplant recipients versus patients with native chronic kidney disease: multicentre unmatched and propensity-score matched analyses.

BACKGROUND: In kidney transplant recipients (KTR), the end-stage kidney disease (ESKD) risk dependent on the risk factors acting in native chronic kidney disease (CKD) remains undefined. METHODS: We compared risk and determinants of ESKD between 757 adult KTR and 1940 patients with native CKD before and after propensity-score (PS) analysis matched for unmodifiable risk factors [(age, sex, diabetes, cardiovascular disease and estimated glomerular filtration rate (eGFR)]. RESULTS: In unmatched cohorts, eGFR was lower in CKD versus KTR (45.9 ± 11.3 versus 59.2 ± 13.4 mL/min/1.73 m2, P < 0.001). During a median follow-up of 5.4 years, the unadjusted cumulative incidence of ESKD was consistently lower in unmatched KTR versus CKD. Conversely, in PS-matched analysis, the risk of ESKD in KTR was 78% lower versus CKD at 1 year of follow-up while progressively increased over time resulting similar to that of native CKD patients after 5 years and 2.3-fold higher than that observed in CKD at 10 years. R2 analysis in unmatched patients showed that the proportion of the outcome variance explained by traditional ESKD determinants was smaller in KTR versus native CKD (31% versus 70%). After PS matching, the risk of ESKD [hazard ratio (HR), 95% confidence interval (95% CI)] was significantly associated with systolic blood pressure (1.02, 1.01-1.02), phosphorus (1.31, 1.05-1.64), 24-h proteinuria (1.11, 1.05-1.17) and haemoglobin (0.85, 0.78-0.93) irrespective of KTR status. Similar data were obtained after matching also for modifiable risk factors. CONCLUSIONS: In KTR, when compared with matched native CKD patients, the risk of ESKD is lower in the first 5 years and higher later on. Traditional determinants of ESKD account for one-third of the variability of time-to-graft failure.

Underlying Genetics of aHUS: Which Connection with Outcome and Treatment Discontinuation?

Atypical hemolytic uremic syndrome (aHUS) is a rare disease caused by a genetic dysregulation of the alternative complement pathway, characterized by thrombocytopenia, hemolytic anemia, and acute kidney injury, and included in the group of thrombotic microangiopathies. With the introduction of humanized monoclonal antibodies that inhibit C5 activation, the natural history of aHUS completely changed, with a better prognosis, a quick recovery of renal function, and a significant reduction of end-stage renal disease incidence. Nowadays, there is an increasing interest in the molecular and genetic bases of this severe disease. The aim of this narrative review is to provide readers with a practical guide about different possible involved genes, elucidating the specific role of each transcribed protein in the pathogenesis of aHUS. Moreover, we analyzed the main current evidence about the relationship among genetic mutations, outcomes, and the risk of recurrence of this manifold disease.

Extracellular vesicles derived from patients with antibody-mediated rejection induce tubular senescence and endothelial to mesenchymal transition in renal cells.

Extracellular vesicles (EV) are emerging mediators in several diseases. However, their role in the pathophysiology of antibody-mediated allograft rejection (AMR) has been poorly investigated. Here, we investigated the role of EV isolated from AMR patients in inducing tubular senescence and endothelial to mesenchymal transition (EndMT) and analyzed their miRNA expression profile. By multiplex bead flow cytometry, we characterized the immunophenotype of plasma AMR-derived EV and found a prevalent platelet and endothelial cell origin. In vitro, AMR-derived EV induced tubular senescence by upregulating SA-ß Gal and CDKN1A mRNA. Furthermore, AMR-derived EV induced EndMT. The occurrence of tubular senescence and EndMT was confirmed by analysis of renal biopsies from the same AMR patients. Moreover, AMR-derived EV induced C3 gene upregulation and CFH downregulation in tubular epithelial cells, with C4d deposition on endothelial cells. Interestingly, RNase-mediated digestion of EV cargo completely abrogated tubular senescence and EndMT. By microarray analysis, miR-604, miR-515-3p, miR-let-7d-5p, and miR-590-3p were significantly upregulated in EV from AMR group compared with transplant controls, whereas miR-24-3p and miR-29a-3p were downregulated. Therefore, EV-associated miRNA could act as active player in AMR pathogenesis, unraveling potential mechanisms of accelerated graft senescence, complement activation and early fibrosis that might lead to new therapeutic intervention.

Altered Phosphorylation of Cytoskeleton Proteins in Peripheral Blood Mononuclear Cells Characterizes Chronic Antibody-Mediated Rejection in Kidney Transplantation.

Chronic antibody-mediated rejection (CAMR) is the major cause of kidney transplant failure. The molecular mechanisms underlying this event are still poorly defined and this lack of knowledge deeply influences the potential therapeutic strategies. The aim of our study was to analyze the phosphoproteome of peripheral blood mononuclear cells (PBMCs), to identify cellular signaling networks differentially activated in CAMR. Phosphoproteins isolated from PBMCs of biopsy proven CAMR, kidney transplant recipients with normal graft function and histology and healthy immunocompetent individuals, have been investigated by proteomic analysis. Phosphoproteomic results were confirmed by Western blot and PBMCs' confocal microscopy analyses. Overall, 38 PBMCs samples were analyzed. A differential analysis of PBMCs' phosphoproteomes revealed an increase of lactotransferrin, actin-related protein 2 (ARPC2) and calgranulin-B in antibody-mediated rejection patients, compared to controls. Increased expression of phosphorylated ARPC2 and its correlation to F-actin filaments were confirmed in CAMR patients. Our results are the first evidence of altered cytoskeleton organization in circulating immune cells of CAMR patients. The increased expression of phosphorylated ARPC2 found in the PBMCs of our patients, and its association with derangement of F-actin filaments, might suggest that proteins regulating actin dynamics in immune cells could be involved in the mechanism of CAMR of kidney grafts.

LPS removal reduces CD80-mediated albuminuria in critically ill patients with Gram-negative sepsis.

LPS-induced sepsis is a leading cause of acute kidney injury (AKI) in critically ill patients. LPS may induce CD80 expression in podocytes with subsequent onset of proteinuria, a risk factor for progressive chronic kidney disease (CKD) frequently observed after AKI. This study aimed to investigate the therapeutic efficacy of LPS removal in decreasing albuminuria through the reduction of podocyte CD80 expression. Between January 2015 and December 2017, 70 consecutive patients with Gram-negative sepsis-induced AKI were randomized to either have coupled plasma filtration and adsorption (CPFA) added to the standard care ( n = 35) or not ( n = 35). To elucidate the possible relationship between LPS-induced renal damage, proteinuria, and CD80 expression in Gram sepsis, a swine model of LPS-induced AKI was set up. Three hours after LPS infusion, animals were treated or not with CPFA for 6 h. Treatment with CPFA significantly reduced serum cytokines, C-reactive protein, procalcitonin, and endotoxin levels in patients with Gram-negative sepsis-induced AKI. CPFA significantly lowered also proteinuria and CD80 urinary excretion. In the swine model of LPS-induced AKI, CD80 glomerular expression, which was undetectable in control pigs, was markedly increased at the podocyte level in LPS-exposed animals. CPFA significantly reduced LPS-induced proteinuria and podocyte CD80 expression in septic pigs. Our data indicate that LPS induces albuminuria via podocyte expression of CD80 and suggest a possible role of timely LPS removal in preventing the maladaptive repair of the podocytes and the consequent increased risk of CKD in sepsis-induced AKI.

Summary of the International Conference on Onco-Nephrology: an emerging field in medicine.

Onco-nephrology is an emerging field in medicine. Patients with cancer may suffer from kidney diseases because of the cancer itself and cancer-related therapy. It is critical for nephrologists to be knowledgeable of cancer biology and therapy in order to be fully integrated in the multidisciplinary team and optimally manage patients with cancer and kidney diseases. In a recent international meeting, the key issues in this challenging clinical interface were addressed, including many unresolved basic science questions, such as the high tumor incidence in kidney transplant recipients. To this end, 70 highly qualified faculty members were gathered from all over the world to discuss these issues in 8 plenary sessions, including 5 keynote lectures. In addition, 48 young nephrologists and oncologists were invited to present their original observations that were highlighted in 2 large poster sessions.

Interleukin-27 is a potential marker for the onset of post-transplant malignancies.

Background: Malignancies represent the third leading cause of post-transplant mortality worldwide. The main challenge for transplant physicians is a timely diagnosis of this condition. The aim of the study was to identify a soluble diagnostic marker for monitoring the development of post-transplant malignancies. Methods: This is a multicentre, observational, perspective, case-control study. We enrolled 47 patients with post-transplant solid neoplasia. As a control group we employed 106 transplant recipients without a history of neoplasia and matched them with cases for the main demographic and clinical features. We investigated the transcriptomic profiles of peripheral blood mononuclear cells from kidney graft recipients with and without post-transplant malignancies enrolled in two of the participating centres, randomly selected from the whole study population. Microarray results were confirmed by quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) in the remaining patients from the same transplant centres and validated in a further independent group enrolled in two different transplant centres. Results: We identified 535 differentially expressed genes comparing patients with and without post-transplant malignancies (fold change ≥2.5; false discovery rate <5%). The cancer pathway was closely related to gene expression data, and one of the most down-regulated genes in this pathway was interleukin-27 (IL-27), a cytokine regulating anti-tumour immunity. Quantitative PCR and ELISA confirmed the microarray data. Interestingly, IL-27 plasma levels were able to discriminate patients with post-transplant neoplasia with a specificity of 80% and a sensitivity of 81%. This observation was confirmed in an independent set of patients from two different transplant centres. Conclusions: Our data suggest that IL-27 may represent a potential immunological marker for the timely identification of post-transplant neoplasia.

mTOR and Aging: An Old Fashioned Dress.

Aging is a physiologic/pathologic process characterized by a progressive impairment of cellular functions, supported by the alterations of several molecular pathways, leading to an increased cell susceptibility to injury. This deterioration is the primary risk factor for several major human pathologies. Numerous cellular processes, including genomic instability, telomere erosion, epigenetic alterations, loss of proteostasis, deregulated nutrient-sensing, mitochondrial dysfunction, stem cell exhaustion, and altered intercellular signal transduction represent common denominators of aging in different organisms. Mammalian target of rapamycin (mTOR) is an evolutionarily conserved nutrient sensing protein kinase that regulates growth and metabolism in all eukaryotic cells. Studies in flies, worms, yeast, and mice support the hypothesis that the mTOR signalling network plays a pivotal role in modulating aging. mTOR is emerging as the most robust mediator of the protective effects of various forms of dietary restriction, which has been shown to extend lifespan and slow the onset of age-related diseases across species. Herein we discuss the role of mTor signalling network in the development of classic age-related diseases, focused on cardiovascular system, immune response, and cancer.

LPS-Binding Protein Modulates Acute Renal Fibrosis by Inducing Pericyte-to-Myofibroblast Trans-Differentiation through TLR-4 Signaling.

During sepsis, the increased synthesis of circulating lipopolysaccharide (LPS)-binding protein (LBP) activates LPS/TLR4 signaling in renal resident cells, leading to acute kidney injury (AKI). Pericytes are the major source of myofibroblasts during chronic kidney disease (CKD), but their involvement in AKI is poorly understood. Here, we investigate the occurrence of pericyte-to-myofibroblast trans-differentiation (PMT) in sepsis-induced AKI. In a swine model of sepsis-induced AKI, PMT was detected within 9 h from LPS injection, as evaluated by the reduction of physiologic PDGFRß expression and the dysfunctional α-SMA increase in peritubular pericytes. The therapeutic intervention by citrate-based coupled plasma filtration adsorption (CPFA) significantly reduced LBP, TGF-ß, and endothelin-1 (ET-1) serum levels, and furthermore preserved PDGFRß and decreased α-SMA expression in renal biopsies. In vitro, both LPS and septic sera led to PMT with a significant increase in Collagen I synthesis and α-SMA reorganization in contractile fibers by both SMAD2/3-dependent and -independent TGF-ß signaling. Interestingly, the removal of LBP from septic plasma inhibited PMT. Finally, LPS-stimulated pericytes secreted LBP and TGF-ß and underwent PMT also upon TGF-ß receptor-blocking, indicating the crucial pro-fibrotic role of TLR4 signaling. Our data demonstrate that the selective removal of LBP may represent a therapeutic option to prevent PMT and the development of acute renal fibrosis in sepsis-induced AKI.

Lysine 63 ubiquitination is involved in the progression of tubular damage in diabetic nephropathy.

The purpose of our study was to evaluate how hyperglycemia (HG) influences Lys63 protein ubiquitination and its involvement in tubular damage and fibrosis in diabetic nephropathy (DN). Gene and protein expression of UBE2v1, a ubiquitin-conjugating E2-enzyme variant that mediates Lys63-linked ubiquitination, and Lys63-ubiquitinated proteins increased in HK2 tubular cells under HG. Matrix-assisted laser desorption/ionization-time of flight/tandem mass spectrometry identified 30 Lys63-ubiquitinated proteins, mainly involved in cellular organization, such as ß-actin, whose Lys63 ubiquitination increased under HG, leading to cytoskeleton disorganization. This effect was reversed by the inhibitor of the Ubc13/UBE2v1 complex NSC697923. Western blot analysis confirmed that UBE2v1 silencing in HK2 under HG, restored Lys63-ß-actin ubiquitination levels to the basal condition. Immunohistochemistry on patients with type 2 diabetic (T2D) revealed an increase in UBE2v1- and Lys63-ubiquitinated proteins, particularly in kidneys of patients with DN compared with control kidneys and other nondiabetic renal diseases, such as membranous nephropathy. Increased Lys63 ubiquitination both in vivo in patients with DN and in vitro, correlated with α-SMA expression, whereas UBE2v1 silencing reduced HG-induced α-SMA protein levels, returning them to basal expression. In conclusion, UBE2v1- and Lys63-ubiquitinated proteins increase in vitro under HG, as well as in vivo in T2D, is augmented in patients with DN, and may affect cytoskeleton organization and influence epithelial-to-mesenchymal transition. This process may drive the progression of tubular damage and interstitial fibrosis in patients with DN.-Pontrelli, P., Conserva, F., Papale, M., Oranger, A., Barozzino, M., Vocino, G., Rochetti, M. T., Gigante, M., Castellano, G., Rossini, M., Simone, S., Laviola, L., Giorgino, F., Grandaliano, G., Di Paolo, S., Gesualdo, L. Lysine 63 ubiquitination is involved in the progression of tubular damage in diabetic nephropathy.

Neutrophil-dependent pentraxin-3 and reactive oxygen species production modulate endothelial dysfunction in haemodialysis patients.

BACKGROUND: The aim of this study was to investigate neutrophil activation and its role in long pentraxin-3 (PTX3) release and oxidative stress generation during haemodialysis (HD) and to correlate neutrophil PTX3 and oxidant expression with endothelial dysfunction. METHODS: Forty-seven uraemic patients on stable HD, 12 healthy subjects and 15 patients with congestive heart failure (New York Heart Association classes III and IV) were enrolled. Neutrophil PTX3 protein expression was evaluated by confocal microscopy. l -selectin expression, intracellular PTX3 localization and reactive oxygen species (ROS) generation in human neutrophils were measured by flow cytometry. NADPH-dependent superoxide generation was investigated by chemiluminescence. PTX3 plasma concentrations were measured by ELISA. Endothelial dysfunction was studied by flow-mediated dilation (FMD). RESULTS: The low baseline levels of FMD significantly improved after HD, but worsened by 24 h. A significant up-regulation of PTX3 protein expression, localized within secondary granules, was detected in neutrophils isolated at 30 and 240 min of HD, along with an increase in l -selectin expression. The up-regulation in intracellular PTX3 in neutrophils was associated with a significant increase in PTX3 plasma concentrations at 240 min. HD increased ROS production and NADPH oxidase activity in neutrophils. In a univariate analysis, pre-treatment with FMD was inversely correlated with PTX3 expression and ROS generation in neutrophils. In a multivariate analysis, both circulating pre-HD PTX3 and intracellular ROS generation by neutrophils were independent predictors of abnormal FMD. CONCLUSIONS: Neutrophil overexpression of PTX3 is associated with ROS overproduction and endothelial dysfunction and may represent an emerging marker of vascular damage progression in HD patients.

Emerging role of Lipopolysaccharide binding protein in sepsis-induced acute kidney injury.

Sepsis remains a serious cause of morbidity and mortality in critically ill patients, with limited therapeutic options available. Of the several disorders connected with sepsis, acute kidney injury (AKI) is one of the major complications. The pathophysiology of sepsis-induced AKI is characterized by severe inflammation in renal parenchyma with endothelial dysfunction, intra-glomerular thrombosis and tubular injury. Endothelial dysfunction is regulated by several mechanisms implicated in cellular de-differentiation, such as endothelial-to-mesenchymal transition (EndMT). Gram-negative bacteria and their cell wall component lipopolysaccharides (LPSs) are frequently involved in the pathogenesis of AKI. The host recognition of LPS requires a specific receptor, which belongs to the Toll-like receptor (TLR) family of proteins, called TLR4, and two carrier proteins, namely the LPS-binding protein (LBP) and cluster of differentiation 14 (CD14). In particular, LBP is released as a consequence of Gram-negative infection and maximizes the activation of TLR4 signalling. Recent findings regarding the emerging role of LBP in mediating sepsis-induced AKI, and the possible beneficial effects resulting from the removal of this endogenous adaptor protein, will be discussed in this review.

mTOR inhibitors effects on regulatory T cells and on dendritic cells.

The mammalian target of rapamycin (mTOR), a cytoplasmic serine/threonine kinase, represents a key biologic "switch" modulating cell metabolisms in response to environmental signals and is now recognized as a central regulator of the immune system. There is an increasing body of evidence supporting the hypothesis that mTOR inhibitors exhibit several biological properties in addition to immunosuppression, including anti-neoplastic effects, cardio-protective activities, and an array of immunomodulatory actions facilitating the development of an operational graft tolerance. The biological mechanisms explaining how mTOR inhibition can enable a tolerogenic state are still largely unclear. The induction of transplant tolerance might at the same time decrease rejection rate and minimize immunosuppression-related side effects, leading to an improvement in long-term graft outcome. In this scenario, T cell immunoregulation has been defined as the hallmark of peripheral tolerance. Two main immunologic cell populations have been reported to play a central role in this setting: regulatory T cells (Tregs) and dendritic cells (DCs). In this review we focus on mTOR inhibitors effects on Treg and DCs differentiation, activation, and function in the transplantation setting.

A type I interferon signature characterizes chronic antibody-mediated rejection in kidney transplantation.

Chronic antibody-mediated rejection (CAMR) represents the main cause of kidney graft loss. To uncover the molecular mechanisms underlying this condition, we characterized the molecular signature of peripheral blood mononuclear cells (PBMCs) and, separately, of CD4(+) T lymphocytes isolated from CAMR patients, compared to kidney transplant recipients with normal graft function and histology. We enrolled 29 patients with biopsy-proven CAMR, 29 stable transplant recipients (controls), and 8 transplant recipients with clinical and histological evidence of interstitial fibrosis/tubular atrophy. Messenger RNA and microRNA profiling of PBMCs and CD4(+) T lymphocytes was performed using Agilent microarrays in eight randomly selected patients per group from CAMR and control subjects. Results were evaluated statistically and by functional pathway analysis (Ingenuity Pathway Analysis) and validated in the remaining subjects. In PBMCs, 45 genes were differentially expressed between the two groups, most of which were up-regulated in CAMR and were involved in type I interferon signalling. In the same patients, 16 microRNAs were down-regulated in CAMR subjects compared to controls: four were predicted modulators of six mRNAs identified in the transcriptional analysis. In silico functional analysis supported the involvement of type I interferon signalling. To further confirm this result, we investigated the transcriptomic profiles of CD4(+) T lymphocytes in an independent group of patients, observing that the activation of type I interferon signalling was a specific hallmark of CAMR. In addition, in CAMR patients, we detected a reduction of circulating BDCA2(+) dendritic cells, the natural type I interferon-producing cells, and their recruitment into the graft along with increased expression of MXA, a type I interferon-induced protein, at the tubulointerstitial and vascular level. Finally, interferon alpha mRNA expression was significantly increased in CAMR compared to control biopsies. We conclude that type I interferon signalling may represent the molecular signature of CAMR.