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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-β 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.

Background The known risks and benefits of native kidney biopsies are mainly based on the findings of retrospective studies. The aim of this multicentre prospective study was to evaluate the safety of percutaneous renal biopsies and quantify biopsy-related complication rates in Italy. Methods The study examined the results of native kidney biopsies performed in 54 Italian nephrology centres between 2012 and 2020. The primary outcome was the rate of major complications 1 day after the procedure, or for longer if it was necessary to evaluate the evolution of a complication. Centre and patient risk predictors were analysed using multivariate logistic regression. Results Analysis of 5304 biopsies of patients with a median age of 53.2 years revealed 400 major complication events in 273 patients (5.1%): the most frequent was a ≥2 g/dL decrease in haemoglobin levels (2.2%), followed by macrohaematuria (1.2%), blood transfusion (1.1%), gross haematoma (0.9%), artero-venous fistula (0.7%), invasive intervention (0.5%), pain (0.5%), symptomatic hypotension (0.3%), a rapid increase in serum creatinine levels (0.1%) and death (0.02%). The risk factors for major complications were higher plasma creatinine levels [odds ratio (OR) 1.12 for each mg/dL increase, 95% confidence interval (95% CI) 1.08–1.17], liver disease (OR 2.27, 95% CI 1.21–4.25) and a higher number of needle passes (OR for each pass 1.22, 95% CI 1.07–1.39), whereas higher proteinuria levels (OR for each g/day increase 0.95, 95% CI 0.92–0.99) were protective. Conclusions This is the first multicentre prospective study showing that percutaneous native kidney biopsies are associated with a 5% risk of a major post-biopsy complication. Predictors of increased risk include higher plasma creatinine levels, liver disease and a higher number of needle passes.

BACKGROUND AND AIMS AKI is the most frequent complication after respiratory failure in COVID-19. AKI increases mortality risk, length of hospital stay and healthcare costs, with possible progression towards CKD. Study aims: (1) evaluation of AKI incidence in 1020 COVID-19 hospitalized patients; (2) comparison of AKI incidence in COVID-19 versus pre-pandemic period; (3) establishment of out-patient follow-up for monitoring kidney, lung, motor and immune function; (4) creation of a biobank for biomarker discovery studies. METHOD AKI incidence was calculated matching laboratory and administrative data of 26 214 hospitalized patients in 2018–2019 and in 1020 COVID-19 patients in 2020–2021: KDIGO algorithms were applied for AKI grading. After 12 months from discharge, 232 COVID AKI patients and relative controls matched for age and gender were evaluated for kidney (eGFR, biomarkers of tubular damage NGAL, CCl-14, DKK-3), lung (DLCO, CT scan) and neuro-motor (SPPB, 2-min walking test, post-traumatic stress test-IES) function. RESULTS Before the pandemic, in-hospital AKI incidence was 18% (10% KDIGO 1, 5% KDIGO 2, 3% KDIGO 3): median age of AKI patients was 69. In-hospital mortality was 3.5% in non-AKI group versus 15% in AKI group in accordance with KDIGO stages. In COVID patients, AKI incidence increased to 37% (20% KDIGO 1.11% KDIGO 2, 6% KDIGO 3): median age of patients was 54. In-hospital mortality was 31% in the AKI group; AKI is an independent risk factor for death. After 12 months from hospital discharge, COVID AKI patients showed a persistent reduction of respiratory function (severe DLCO impairment CONCLUSION AKI incidence was significantly increased during COVID-19 in respect to the pre-pandemic period, with an association with higher mortality in class 2–3 KDIGO. In the post-COVID follow-up, AKI was associated with lung and neuro-motor function impairment, a defective antibody response and a sudden GFR decline concomitant to the persistence of tubular injury biomarkers. These results suggest the importance of nephrological and multidisciplinary follow-up of frail patients who developed AKI during hospitalization for COVID-19.

Current treatment of primary and secondary glomerulopathies is hampered by many limits and a significant proportion of these disorders still evolves towards end-stage renal disease. A possible answer to this unmet challenge could be represented by therapies with stem cells, which include a variety of progenitor cell types derived from embryonic or adult tissues. Stem cell self-renewal and multi-lineage differentiation ability explain their potential to protect and regenerate injured cells, including kidney tubular cells, podocytes and endothelial cells. In addition, a broad spectrum of anti-inflammatory and immunomodulatory actions appears to interfere with the pathogenic mechanisms of glomerulonephritis. Of note, mesenchymal stromal cells have been particularly investigated as therapy for Lupus Nephritis and Diabetic Nephropathy, whereas initial evidence suggest their beneficial effects in primary glomerulopathies such as IgA nephritis. Extracellular vesicles mediate a complex intercellular communication network, shuttling proteins, nucleic acids and other bioactive molecules from origin to target cells to modulate their functions. Stem cell-derived extracellular vesicles recapitulate beneficial cytoprotective, reparative and immunomodulatory properties of parental cells and are increasingly recognized as a cell-free alternative to stem cell-based therapies for different diseases including glomerulonephritis, also considering the low risk for potential adverse effects such as maldifferentiation and tumorigenesis. We herein summarize the renoprotective potential of therapies with stem cells and extracellular vesicles derived from progenitor cells in glomerulonephritis, with a focus on their different mechanisms of actions. Technological progress and growing knowledge are paving the way for wider clinical application of regenerative medicine to primary and secondary glomerulonephritis: this multi-level, pleiotropic therapy may open new scenarios overcoming the limits and side effects of traditional treatments, although the promising results of experimental models need to be confirmed in the clinical setting.

Background and Aims Very few information about COVID-19 in kidney transplant recipients (KTRs) are known and the available evidence are based on limited case series. In KTRs, Acute Kidney Injury (AKI) of different causes is known to be associated with a decreased graft survival: direct viral infection and local inflammation may potentially lead to a premature loss of graft function and to an increased risk of death in COVID-19 patients. To evaluate prevalence, stage, causes of AKI and mortality in KTRs with a positive pharyngeal swab for SARS-CoV-2 in our transplant center located in a 500-bed University Hospital. Method In March-June 2020, we evaluated in 25 COVID-19 KTRs demographic and transplant characteristics, comorbidities, immunosuppressive therapies (IT). Patients were screened for type of symptoms, management of IT, complications and outcome. AKI was graded according to 2012 KDIGO guidelines and causes were investigated basing on both clinical and laboratory variables. AKI prevalence in KTRs was compared to that observed in the whole hospitalized COVID-19 patients. Results During the first wave of pandemic, a total of 945 patients were admitted to our hospital with a reported AKI prevalence of 37%. AKI classified using 2012 KDIGO guidelines associated with an increased mortality risk in the whole population. In this setting, we observed that 25 KTRs followed-up in our University Hospital had a positive molecular diagnosis for COVID-19: median age was 58 years and 80% were males. Considering the most frequent comorbidities, 100% of KTRs had hypertension and 7/25 (29%) had diabetes. Clinical symptoms at enrollment were fever (95%), cough (47%), dyspnea (30%). Regarding IT, 100% of patients were taking CNI, 64% antimetabolite agents and 76% steroids. Of note, 19/25 patients (76%) were hospitalized and 6/19 (31.5%) were admitted to Intensive Care Unit (ICU). Mean length of hospital stay was 23 days. At admission, all KTRs stopped MMF and increased steroid doses, concomitantly decreasing CNI levels. AKI occurred in 60% of KTRs (12/25), AKI KDIGO grading as follow: stage 1 4/12 (33.3%), stage 2 3/12 (25%), stage 3 5/12 (41.7%); development favored by low eGFR/increased serum creatinine (mean serum creatinine 2.06 mg/dl): 4/25 (16%) required hemodialysis and the most frequent cause of AKI was sepsis or septic shock. Overall mortality in KTRs was 37,5% (9/25): of note, 88% (8/9) of patients with a worse outcome had developed AKI. Conclusion AKI prevalence was significantly higher in KTRs than in non-transplanted COVID-19 patients. AKI development was associated with an increased risk of mortality: of note, mortality rate in KTRs was significantly higher than that observed in the non-transplanted patients. COVID-19 lead to a difficult management of IT, in particular for elevated tacrolimus levels due to associated antiviral and antibiotic therapies. COVID-19-associated AKI in KTRs may lead to an increased risk of rejection and premature loss of graft function with the need of skilled nephrological follow-up.

Background and Aims In 2020, SARS-CoV-2 pandemic had a devastating impact on individuals and on national health systems worldwide. Although being primarily a lung disease, COVID-19-associated systemic inflammation and activation of coagulation/complement cascades lead to multiple organ dysfunction including Acute Kidney Injury (AKI). Our aim is to evaluate AKI prevalence and mortality in hospitalized patients during COVID-19 pandemic in a 500-bed University Hospital. Method Observational study on 945 COVID-19 patients (March-May 2020). Data collection from Board Hospital Discharge and serum creatinine (Lab database). AKI stratification in accordance to KDIGO criteria and evaluation of outcome in the different subgroups. The same methodology was adopted to assess AKI prevalence and outcome in 2018-2019. Results 351/945 (37.14%) of all hospital admissions for COVID-19 showed AKI further sub-classified as follows: 173 (18.3%) stage 1, 112 (11.9%) stage 2 and 66 (6.9%) stage 3: the control NO AKI group was 594/945 (62.86%). COVID-associated AKI prevalence was higher than that observed in 2018 (total AKI 17.9%, stage 1 10.7%, stage 2 4.5%, stage 3 2.7%) and 2019 (total AKI 17.2%, stage 1 10.1%, stage 2 4.5%, stage 3 2.6%). During COVID-19 pandemic, in-hospital mortality was 27% for NO AKI group, 28% for total AKI group, further subdivided 24% for stage 1, 45% for stage 2 and 42% for stage 3 group, respectively. Mortality was different from that observed during 2018 (NO AKI 3.77%, total AKI 15.2%, stage 1 9.69%, stage 2 17.24%, stage 3 18.9%) and 2019 (NO AKI 3.56%, total AKI 18.35%, stage 1 10.6%, stage 2 20.1%, stage 3 24.3%). In COVID-19 patients, mean age of NO AKI group was 64.6 ys vs. 71.7 ys of total AKI group divided in 71.6 ys for stage 1, 74.3 ys for stage 2 and 67.9 ys for stage 3, respectively. Mean eGFR at admission was 74.2 ml/min for NO AKI group, 61.3 ml/min for total AKI group divided in 64.3 ml/min for stage 1, 57.8 ml/min for stage 2 and 52.5 ml/min for stage 3. Mean serum creatinine at admission was 1.17 mg/dl in NO AKI group, 1.43 mg/dl for total AKI group divided in1.22 mg/dl for stage 1, 1.4 mg/dl for stage 2 and 2.25 mg/dl for stage 3. Among evaluated comorbidities, only diabetes (p=0,048) and cognitive impairment (p=0,001) were associated with a significant increased risk for AKI development. ICU admission rate was 5% for NO AKI group and 18% for total AKI group divided in 14% for stage 1, 22% for stage 2 and 44% for stage 3. Mean length of hospital stay for NO AKI group was 7.22 days vs 15.08 days for total AKI group divided in 13.67 for stage 1, 15.83 for stage 2 and 21.82 for stage 3. Of note, all different therapies administered to COVID-19 patients did not correlate with AKI incidence. Mean eGFR at discharge was 76 ml/min for NO AKI group vs 66 ml/min for total AKI group divided in 68.7 ml/min for stage 1, 59.3 ml/min for stage 2 and 59.3 ml/min for stage 3. Mean serum creatinine at discharge was 1.14 mg/dl for NO AKI group vs 1.45 mg/dl for total AKI group divided in 1.28 mg/dl for stage 1, 1.58 mg/dl for stage 2 and 2.05 mg/dl for stage 3. Conclusion COVID-19 pandemic is associated with an increased AKI prevalence in hospitalized patients (2-fold increase in all KDIGO stages). AKI associated with an increased risk of mortality: of note, AKI stage2-3 had a strong impact on mortality in comparison to NO AKI group (OR 2.59 and 2.11, respectively). The presence of eGFR >60 ml/min and serum creatinine < 1.2 mg/dl at admission were associated with a lower risk of AKI development: reduced eGFR levels were observed at discharge particularly in AKI stage 2-3. The length of hospital stay and risk of ICU admission depended on AKI incidence and severity. COVID-19 lead to an increased burden for Nephrologists due to increased AKI prevalence: a nephrological follow-up is needed to avoid progression from AKI to chronic kidney disease (CKD).

A causal link between viral infections and autoimmunity has been studied for a long time and the role of some viruses in the induction or exacerbation of systemic lupus erythematosus (SLE) in genetically predisposed patients has been proved. The strength of the association between different viral agents and SLE is variable. Epstein–Barr virus (EBV), parvovirus B19 (B19V), and human endogenous retroviruses (HERVs) are involved in SLE pathogenesis, whereas other viruses such as Cytomegalovirus (CMV) probably play a less prominent role. However, the mechanisms of viral–host interactions and the impact of viruses on disease course have yet to be elucidated. In addition to classical mechanisms of viral-triggered autoimmunity, such as molecular mimicry and epitope spreading, there has been a growing appreciation of the role of direct activation of innate response by viral nucleic acids and epigenetic modulation of interferon-related immune response. The latter is especially important for HERVs, which may represent the molecular link between environmental triggers and critical immune genes. Virus-specific proteins modulating interaction with the host immune system have been characterized especially for Epstein–Barr virus and explain immune evasion, persistent infection and self-reactive B-cell “immortalization”. Knowledge has also been expanding on key viral proteins of B19-V and CMV and their possible association with specific phenotypes such as antiphospholipid syndrome. This progress may pave the way to new therapeutic perspectives, including the use of known or new antiviral drugs, postviral immune response modulation and innate immunity inhibition. We herein describe the state-of-the-art knowledge on the role of viral infections in SLE, with a focus on their mechanisms of action and potential therapeutic targets.

Background A cyclic corticosteroid-cyclophosphamide regimen is the first-line therapy for membranous nephropathy. Compared with this regimen, rituximab therapy might have a more favorable safety profile, but a head-to-head comparison is lacking. Methods We randomly assigned 74 adults with membranous nephropathy and proteinuria >3.5 g/d to rituximab (1 g) on days 1 and 15, or a 6-month cyclic regimen with corticosteroids alternated with cyclophosphamide every other month. The primary outcome was complete remission of proteinuria at 12 months. Other outcomes included determination of complete or partial remission at 24 months and occurrence of adverse events. Results At 12 months, six of 37 patients (16%) randomized to rituximab and 12 of 37 patients (32%) randomized to the cyclic regimen experienced complete remission (odds ratio [OR], 0.4; 95% CI, 0.13 to 1.23); 23 of 37 (62%) receiving rituximab and 27 of 37 (73%) receiving the cyclic regimen had complete or partial remission (OR, 0.61; 95% CI, 0.23 to 1.63). At 24 months, the probabilities of complete and of complete or partial remission with rituximab were 0.42 (95% CI, 0.26 to 0.62) and 0.83 (95% CI, 0.65 to 0.95), respectively, and 0.43 (95% CI, 0.28 to 0.61) and 0.82 (95% CI, 0.68 to 0.93), respectively, with the cyclic regimen. Serious adverse events occurred in 19% of patients receiving rituximab and in 14% receiving the cyclic regimen. Conclusions This pilot trial found no signal of more benefit or less harm associated with rituximab versus a cyclic corticosteroid-cyclophosphamide regimen in the treatment of membranous nephropathy. A head-to-head, pragmatic comparison of the cyclic regimen versus rituximab may require a global noninferiority trial. Clinical trial registry name and registration number Rituximab versus Steroids and Cyclophosphamide in the Treatment of Idiopathic Membranous Nephropathy (RI-CYCLO), NCT03018535.

New biomarkers of early and late graft dysfunction are needed in renal transplant to improve management of complications and prolong graft survival. A wide range of potential diagnostic and prognostic biomarkers, measured in different biological fluids (serum, plasma, urine) and in renal tissues, have been proposed for post-transplant delayed graft function (DGF), acute rejection (AR), and chronic allograft dysfunction (CAD). This review investigates old and new potential biomarkers for each of these clinical domains, seeking to underline their limits and strengths. OMICs technology has allowed identifying many candidate biomarkers, providing diagnostic and prognostic information at very early stages of pathological processes, such as AR. Donor-derived cell-free DNA (ddcfDNA) and extracellular vesicles (EVs) are further promising tools. Although most of these biomarkers still need to be validated in multiple independent cohorts and standardized, they are paving the way for substantial advances, such as the possibility of accurately predicting risk of DGF before graft is implanted, of making a “molecular” diagnosis of subclinical rejection even before histological lesions develop, or of dissecting etiology of CAD. Identification of “immunoquiescent” or even tolerant patients to guide minimization of immunosuppressive therapy is another area of active research. The parallel progress in imaging techniques, bioinformatics, and artificial intelligence (AI) is helping to fully exploit the wealth of information provided by biomarkers, leading to improved disease nosology of old entities such as transplant glomerulopathy. Prospective studies are needed to assess whether introduction of these new sets of biomarkers into clinical practice could actually reduce the need for renal biopsy, integrate traditional tools, and ultimately improve graft survival compared to current management.

Background and Aims EVs (Extracellular vesicles) are circulating microparticles able to mediate cell-to cell communication by carrying proteins, DNA, RNA or antibodies on their surface. EV are emerging as pivotal in renal Antibody-mediated rejection (AMR), one of the major causes of transplant failure associated to a massive complement activation. AMR is characterized by endothelial to mesenchymal transition (EndMT) and the occurrence of tubular accelerated senescence process, known as graft “Inflammaging”. However, the potential role of EVs in accelerating the renal aging and graft fibrosis after AMR is not well understood. Method Plasma EVs were isolated from 10 Acute AMR (AAMR), 10 Chronic AMR (CAMR) patients, 5 stable graft transplanted patients and 5 healthy volunteers. EVs were isolated by ultracentrifugation at 100.000 g for 1h at 4°C, quantified by Nanoparticle Tracking Analysis (Nanosight, NTA EV/ml) and characterized by FACS (Attune Nxt). RPTEC and endothelial cell culture were incubated with EVs (5e+4 EVs/cells target for 24h. MTT test was performed to assess cell viability. Cellular senescence was investigated by qPCR for p21, p53, Klotho and CYP1B1 and SA-β-gal staining were performed. To assess EndMT analysis for CD31, VE-cadherin, Vimentin, Collagen I was performed by FACS. mRNA level of C3 and CFH were also measured by qPCR and C4d deposits were evaluated in endothelial cell colture by IF. Renal biopsies were then analyzed for inflammaging (p16INK4a) and EndMT markers (CD31/αSMA) by IHC and IF. Results The Nanosight analysis showed significant differences in the amount of-EVs count per ml of plasma in AMR patients compared to healthy subjects. EVs appeared to be significantly augmented in acute AMR, in a higher manner than chronic AMR (NTA, p=0.0154). By cytofluorimetric analysis, the endothelial markers CD31 and VE- cadherin appeared to be significantly increased compared of healthy control, indicating a predominant endothelial EV origin (p Conclusion These results suggest a putative role for circulating AMR derived-EVs in inducing the tubular inflammaging by local complement activation and early fibrosis by EndMT. The EVs cargo characterization that is ongoing might highlight novel targets for therapeutic intervention.

Autosomal Dominant Tubulointerstitial Kidney Diseases (ADTKD) are a group of autosomal dominant hereditary nephropathies which share a rather aspecific pathological picture of interstitial fibrosis...

Kidney transplantation (KT) may restore fertility in chronic kidney disease (CKD). The reasons why maternofetal outcomes are still inferior to the overall population are only partially known. Comparison with the CKD population may offer some useful insights for management and counselling.Aim of this study was to analyse the outcomes of pregnancy after KT, compared with a large population of nontransplanted CKD patients and with low-risk control pregnancies, observed in Italy the new millennium.We selected 121 live-born singletons after KT (Italian study group of kidney in pregnancy, national coverage about 75%), 610 live-born singletons in CKD, and 1418 low-risk controls recruited in 2 large Italian Units in the same period (2000-2014). The following outcomes were considered: maternal and fetal death; malformations; preterm delivery; small for gestational age (SGA) baby; need for the neonatal intensive care unit; doubling of serum creatinine or increase in CKD stage. Data were analyzed according to kidney diseases, renal function (staging according to CKD-epidemiology collaboration), hypertension, maternal age, parity, ethnicity.Maternofetal outcomes are less favourable in CKD and KT as compared with the low-risk population. CKD stage and hypertension are important determinants of results. Kidney transplantation patients with estimated glomerular filtration rate greater than 90 have worse outcomes compared with CKD stage 1 patients; the differences level off when only CKD patients affected by glomerulonephritis or systemic diseases ("progressive CKD") are compared with KT. In the multivariate analysis, risk for preterm and early-preterm delivery was linked to CKD stage (2-5 vs 1: relative risk 3.42 and 3.78) and hypertension (RR 3.68 and 3.16) while no difference was associated with being a KT or a CKD patient.The maternofetal outcomes in patients with kidney transplantation are comparable with those of nontransplanted CKD patients with similar levels of kidney function impairment and progressive and/or immunologic kidney disease.

Immune cell-derived extracellular vesicles (EVs) are known immune-modulators and exert a critical role in kidney transplantation (KTx). EV bioactive cargo includes graft antigens, costimulatory/inhibitory molecules, cytokines, growth factors and functional microRNAs (miRNAs) that modulate expression of recipient cell target genes. At cellular level, neutrophil- and macrophage-derived EVs exert respectively immunosuppressive and immune-stimulating effects on dendritic cells. Dendritic cell-derived EVs mediate alloantigen spreading among them and modulate antigen-presentation to T lymphocytes. At systemic level, EVs exert pleiotropic effects on complement and coagulation. Depending on their biogenesis, they can amplify complement activation, or shed complement-inhibitors and prevent cell lysis. Likewise, endothelial and platelet-derived EVs can exert pro-coagulant/pro-thrombotic effects but also promote endothelial survival and angiogenesis after ischemic injury. Kidney endothelial and tubular-derived EVs play a key-role in ischemia-reperfusion injury and, during the healing process, can trigger rejection by inducing both allo- and autoimmune responses. Endothelial EVs have pro-coagulant/pro-inflammatory effects and can release sequestered self-antigens, triggering a tissue-specific autoimmunity. Renal tubule-derived EVs shuttle pro-fibrotic mediators (TGFβ, miR21) to interstitial fibroblasts and modulate neutrophil and T-lymphocyte influx. These processes can lead to peritubular capillary rarefaction and interstitial fibrosis-tubular atrophy. Different EVs, including those from mesenchymal stromal cells, have been employed as therapeutic tool in experimental models of rejection and ischemia-reperfusion injury. These particles protect tubular and endothelial cells (by inhibition of apoptosis and inflammation-fibrogenesis and autophagy induction) and stimulate tissue regeneration (by triggering angiogenesis, cell proliferation and migration). Finally, urinary and serum EVs represent potential biomarkers for delayed graft function and acute rejection. In conclusion, EVs sustain an intricate cross talk between graft tissue and innate/adaptive immune systems. EVs play a major role in allorecognition, ischemia-reperfusion injury, auto- and alloimmunity, and are promising as biomarkers and therapeutic tools in KTx.

BACKGROUND Chronic T cell-mediated rejection (TCMR) in kidney graft is characterized by reduction of the vessel lumen with marked intimal thickening, fibrous hyperplasia of the small renal arteries and leukocyte infiltrates. The aim of this study was to find specific gene expression profiles in chronic TCMR kidney biopsies. METHODS RNA extracted from archival formalin-fixed, paraffin-embedded renal biopsies was used for gene expression profiling. Our study included 14 patients with chronic TCMR and 10 with acute TCMR. Fifty-two cadaveric donors were used as controls. The results were validated in an independent set of kidney biopsies. RESULTS We identified 616 and 243 differentially expressed genes with a fold change ≥1.5 and a false discovery rate

Renal tubular acidosis (RTA) refers to a group of disorders of multiple etiology characterised by a hyperchloremic, normal anion-gap metabolic acidosis caused by different defects affecting several mechanisms of urinary acidification: an impaired secretion of protons by collecting duct in distal hypokalemic RTA (type 1), impaired resorption of bicarbonate in proximal RTA (type 2), a mixed proximal and distal defect in RTA type 3 and an impaired ammoniagenesis due to an absolute or functional hypoaldosteronism in distal hyperkalemic RTA (type 4). Etiology is heterogeneous and ranges from primitive genetic forms to secondary RTA within a multi-system disorder such as autoimmune disease, paraproteinemia and calcium-phosphate disorders. Drug-induced RTA has been increasingly reported over the last decade due to widespread use of some molecules (e.g. antiviral and oncologic agents, inhibitors of renin-angiotensin system). The diagnosis of RTA is based on assessment of serum and urine anion-gap, whereas differe...

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host-response to infections. Osteopontin (OPN) is an extracellular matrix protein involved in the inflammatory response. Our aim was to evaluate the diagnostic and prognostic performance in sepsis of a single OPN determination in the Emergency Department (ED). We conducted a single-centre prospective observational study in an Italian ED where we enrolled 102 consecutive patients presenting with suspected infection and qSOFA &ge, 2. OPN plasma concentration was found to be an independent predictor of sepsis (OR = 1.020, 95% CI 1.002&ndash, 1.039, P = 0.031) and the diagnostic receiver operating characteristic (ROC) curve resulted in an area under the curve (AUC) of 0.878. OPN levels were positively correlated to plasma creatinine (r = 0.401 with p = 0.0001), but this relation was not explained by the development of acute kidney injury (AKI), since no difference was found in OPN concentration between AKI and non-AKI patients. The analysis of 30-days mortality showed no significant difference in OPN levels between alive and dead patients (p = 0.482). In conclusion, a single determination of OPN concentration helped to identify patients with sepsis in the ED, but it was not able to predict poor prognosis in our cohort of patients.

Aim: To perform a systematic review and meta-analysis of studies evaluating the influence of recipient angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism on kidney function in renal transplant recipients. Materials & methods: A comprehensive search was performed through PubMed, Web of Knowledge and Cochrane databases up to December 2014. The methodological quality of identified studies was assessed using the MINORS criteria. Results: A total of 15 studies evaluating the role of recipient ACE I/D were included in the meta-analysis. In overall analyzes and subsequent subgroup and sensitivity analyzes, no evidence emerged of an effect of ACE I/D on serum creatinine levels, creatinine clearance or glomerular filtration rate. Conclusion: Although further investigation is still needed to determine the role of donor ACE genotype, recipient ACE I/D does not play a significant role on kidney function in renal transplant patients.

Rituximab (RTX), a B-lymphocytes depleting monoclonal antibody, deeply changed the therapeutic landscape of secondary glomerulonephritis in the past decade.RTX has proved to be as effective as cyclophosphamide in inducing remission in ANCA-associated vasculitis and better than azathioprine as maintenance therapy in three different RCT. Treatment's duration and modality, however, remain debated.RTX has been widely used in resistant or relapsing proliferative lupus nephritis (LN), with positive results reported by retrospective studies; however, when employed as an “add-on” induction therapy in a RCT, it did not show a definite additive effect to standard therapy with mycophenolate mofetil and steroid in moderate forms of LN. In prospect, it remains a promising tool both as second-line therapy for resistant forms and as a “steroid-sparing” agent to strengthen induction and to allow reduced or minimal maintenance therapy.RTX is effective in the treatment of HCV-related cryoglobulinemic vasculitis, including ...

Background The renal assist device (RAD) is a blood purification system containing viable renal tubular epithelial cells (TECs) that has been proposed for the treatment of acute kidney injury (AKI) and multiple organ failure. Perfluorocarbons (PFCs) are oxygen carriers used for organ preservation in transplantation. The aim of this study was to investigate the effect of PFCs on hypoxia- and sepsis-induced TEC injury and on renal CD133+ progenitor differentiation in a microenvironment similar to the RAD. Methods TECs were seeded in a polysulphone hollow fibre under hypoxia or cultured with plasma from 10 patients with sepsis-associated AKI in the presence or absence of PFCs and were tested for cytotoxicity (XTT assay), apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling assay, caspases, enzyme-linked immunosorbent assay, Fas/Fas Ligand pathway activation), mitochondrial activity, cell polarity [transepithelial electrical resistance (TEER)] and adenosine triphosphate production. The effect of PFCs on proliferation and differentiation of human CD133+ progenitors was also studied. Results In the presence of PFCs, TECs seeded into the polysulphone hollow fibre showed increased viability and expression of insulin-like growth factor 1, hepatocyte growth factor and macrophage-stimulating protein. Plasma from septic patients induced TEC apoptosis, disruption of oxidative metabolism, alteration of cell polarity and albumin uptake, down-regulation of the tight junction protein ZO-1 and the endocytic receptor megalin on the TEC surface. These detrimental effects were significantly reduced by PFCs. Moreover, PFCs induced CD133+ renal progenitor cell proliferation and differentiation towards an epithelial/tubular-like phenotype. Conclusions PFCs improved the viability and metabolic function of TECs seeded within a polysulphone hollow fibre and subjected to plasma from septic AKI patients. Additionally, PFCs promoted differentiation towards a tubular/epithelial phenotype of CD133+ renal progenitor cells.

Despite the growing interest in daily hemodialysis (DHD), logistic and economic factors limit its dissemination. Not the least of these factors is the lack of uniform criteria for measuring efficiency. From November 1998 to November 2000, 19 patients were on DHD in our unit. The dialysis prescription was bicarbonate buffer; 6 sessions per week; 2 - 3 hours; blood flow 250 - 350 mL/min; individual K, HCO3 , and Na levels; membrane 1.6 - 2 m2 (polysulfone, polycarbonate). The prescription represented the minimum dialysis requirement; patients were free to add up to 30 minutes per session, further increase or any decreases needed confirmation by the caregivers. The aim of the study was to assess Kt/Vurea variability in this clinical setting, and to identify the minimum number of dialysis sessions required to obtain a reliable estimate of weekly Kt/Vurea [relative error (RE) < 10%]. We studied 169 dialysis sessions in 13 clinically stable patients on DHD for ≥ 3 months, with ≥ 3 Kt/Vurea measurements within 2 weeks (median: 10; range: 3 - 32 sessions), tested in the same laboratory. To assess variability, we employed the simplest formula (the Lowrie Kt/Vurea ), the widely used Daugirdas II formula, and the derived single-pool equivalent renal clearance (EKRc ), according to Casino. The variability of Kt/Vurea per session was high (Lowrie: RE = 2.5% - 22.1%; Daugirdas II and EKRc : RE = 3.6% - 24%). Averaging several dialysis sessions leads to a more reliable estimate of weekly efficiency (6 sessions: RE = 0; 3 sessions, Lowrie formula: Kt/Vurea RE = 1.1% - 9.7%; Daugirdas II and EKRc : RE = 1.6% - 10.6%). In patients with wide time variations, variability may be lower if weekly efficiency is determined on the basis of "average hourly Kt/Vurea ," which is calculated by dividing Kt/Vurea by the number of hours in the studied sessions, and then multiplying by the hours of dialysis performed in the whole week (Lowrie formula, Kt/Vurea : RE = 4.8% - 16.6% for 1 session, 2.1% - 7.3% for 3 sessions). Once again, the RE decreases sharply when data from 3 sessions are considered. Therefore, for flexible DHD, we suggest averaging the data from ≥ 3 sessions for weekly Kt/Vurea assessment.

Daily hemodialysis (DHD) is a promising option; however, logistic obstacles and clinical perplexities limit its dissemination. Understanding the mechanisms of, and the time until, the onset of improved well-being may help to quantify clinical advantages and to define the minimum length of a "trial" of daily dialysis. By following 30 patients treated in 4 centers, this study aimed to determine how long a period of time is needed until a patient experiences subjective improvement. From November 1998 to November 2000, 30 patients tried at least 2 weeks of short daily dialysis in four Northern Italian centers of Piemonte and Valle d'Aosta. The DHD (2 - 3 hours; blood flow 270 - 350 mL/min; individual HCO3 , Na, K) was performed at home or in a center. Motivations to try DHD, fears and concerns regarding DHD, and changes in perceived well-being were assessed by semi-structured interview. The main clinical indications for a trial of DHD were poor tolerance of conventional treatment, cardiovascular disease, and hypertension or hypotension; only 6 patients had no comorbidity at start. The patients' main reasons for choosing DHD were related to job problems and the search for a better treatment. Most of the patients continued DHD because of improved well-being; logistic reasons accounted for the drop-outs (5 patients). The main fears were related to logistic aspects, vascular access problems, and excessive involvement of the partner on home dialysis. Improved well-being was reported by 28 of 30 patients; 2 patients reported no difference. Subjective improvement was perceived within 2 weeks in 22 of 30 patients, and within 1 month in 28 of 30 patients. An offer of a 2 - 4 week trial of DHD may help patients and caregivers to determine whether subjective and objective benefits outweigh logistic problems and whether a permanent transfer to DHD is worthwhile.

Complex interactions between tumor and host cells regulate systemic tumor dissemination, a process that begins early at the primary tumor site and goes on until tumor cells detach themselves from the tumor mass and start migrating into the blood or lymphatic vessels. Metastatic cells colonize the target organs and are capable of surviving and growing at distant sites. In this context, osteopontin (OPN) appears to be a key determinant of the crosstalk between cancer cells and the host microenvironment, which in turn modulates immune evasion. OPN is overexpressed in several human carcinomas and has been implicated in inflammation, tumor progression, and metastasis. Thus, it represents one of the most attracting targets for cancer therapy. Within the tumor mass, OPN is secreted in various forms either by the tumor itself or by stroma cells, and it can exert either pro- or antitumorigenic effects according to the cell type and tumor microenvironment. Thus, targeting OPN for therapeutic purposes needs to take into account the heterogeneous functions of the multiple OPN forms with regard to cancer formation and progression. In this review, we will describe the role of systemic, tumor-derived, and stroma-derived OPN, highlighting its pivotal role at the crossroads of inflammation and tumor progression.

TCF7L2 rs7903146 CT polymorphism is associated with diabetes in the general population but its independent impact on cardiovascular disease is debated. On this basis, we investigated its association with major adverse cardiac events (MACE) in a single-center cohort of non-diabetic kidney transplant recipients (KTRs).Patients with pretransplant diabetes were excluded and patients who developed post-transplant diabetes were censored at time of diagnosis.rs7903146 CT polymorphism appeared to modulate the risk of MACE: 5-year prevalence was 0.8% in CC patients, 7.2% in CT patients and 9.7% in TT patients (P.001). TCF7L2 rs7903146 was an independent predictor of MACE in a multivariate Cox regression model (for each T allele, HR: 2.99, 95%CI: 1.62-5.52, P.001), together with history of cardiac ischemic events (HR: 8.69, 95%CI: 3.57-21.16, P.001), DGF (HR: 2.42, 95%CI: 0.98-5.95, P=.056) and HLA-mismatches (for each mismatch: HR: 1.55, 95%CI: 1.00-2.43, P=.053). Introduction of rs7903146 CT polymorphism into a model based on these clinical variables significantly increased predictive power for MACE (P=.003).TCF7L2 rs7903146 T allele may be strongly and independently associated with MACE in non-diabetic KTRs. These findings suggest the possibility of employing this SNP to more accurately stratify cardiological risk in KTRs.

Type IV renal tubular acidosis (RTA IV) is a form of hyperchloremic RTA caused by an absolute or functional hypoaldosteronism that determines a distal acidification defect by inhibiting ammoniagene...

The aim of this study was to determine whether detection of β-HPV gene products, as defined in epidermodysplasia verruciformis skin cancer, could also be observed in lesions from kidney transplant recipients alongside the viral DNA. A total of 111 samples, corresponding to 79 skin lesions abscised from 17 kidney transplant recipients, have been analyzed. The initial PCR analysis demonstrated that β-HPV-DNA was highly present in our tumor series (85%). Using a combination of antibodies raised against the E4 and L1 proteins of the β-genotypes, we were able to visualize productive infection in 4 out of 19 actinic keratoses, and in the pathological borders of 1 out of 14 squamous cell carcinomas and 1 out of 31 basal cell carcinomas. Increased expression of the cellular proliferation marker minichromosome maintenance protein 7 (MCM7), that extended into the upper epithelial layers, was a common feature of all the E4-positive areas, indicating that cells were driven into the cell cycle in areas of productive viral infections. Although the present study does not directly demonstrate a causal role of these viruses, the detection of E4 and L1 positivity in actinic keratosis and the adjacent pathological epithelium of skin cancer, clearly shows that β-HPV are actively replicating in the intraepidermal precursor lesions of kidney transplant recipients and can therefore cooperate with other carcinogenic agents, such as UVB, favoring skin cancer promotion.

Background Patients with a rare genetic disease may receive renal transplantation (KTx) without a correct diagnosis of causal nephropathy and therefore develop unexpected and even severe complications. The aim of the study was to describe the cases of rare genetic disorders diagnosed after KTx, in order to draw clinical lessons for the transplant physician. Methods We retrospectively assessed all patients who had received a diagnosis of a rare genetic disorder after KTx. Results In our center, more than 30% (278/911) of kidney transplant (KTx) recipients were diagnosed with a causal nephropathy: Prevalence of rare genetic disorders in this group was 4.32% (12/278), including 2,8-dihydroxyadeninuria (2,8-DHA) disease (n = 2), HNF-1B-associated nephropathy (n = 2), UMOD-related nephropathy (n = 5), Fabry disease (n = 1), INF2 focal segmental glomerulosclerosis (n = 1), and Senior-Loken syndrome (n = 1). 2,8-DHA nephropathy relapsed in both patients causing an acute renal failure and jeopardizing the graft. Conclusions Kidney transplant recipients without a diagnosis of causal nephropathy appear to be a selected population in which rare genetic diseases might be more common than expected. As even a belated diagnosis after KTx can have a significant impact on graft and patient survival and on other family members, this possibility should be evaluated in KTx recipients without a known causal nephropathy.