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Federica Maritati, Claudia Bini, Vania Cuna, Francesco Tondolo, Sarah Lerario, Valeria Grandinetti, Marco Busutti, Valeria Corradetti, Gaetano La Manna, Giorgia Comai Nephrology, Dialysis and Renal Transplant Unit, IRCCS-Azienda Ospedaliero-Universitaria di Bologna, Bologna, ItalyCorrespondence: Gaetano La Manna, Nephrology, Dialysis and Renal Transplant Unit, IRCCS-Azienda Ospedaliero-Universitaria di Bologna, Via Giuseppe Massarenti, 13, Bologna, 40138, Italy, Tel +39-051-2142584, Fax +39-051-2142509, Email gaetano.lamanna@unibo.itAbstract: For a long time, ABO incompatible living donor kidney transplantation has been considered contraindicated, due to the presence of isohemagglutinins, natural antibodies reacting with non-self ABO antigens. However, as the demand for kidney transplantation is constantly growing, methods to expand the donor pool have become increasingly important. Thus, in the last decades, specific desensitization strategies for ABOi transplantation have been developed. Nowadays, these regimens consist of transient removal of preformed anti-A or anti-B antibodies by using plasmapheresis or immunoadsorption and B-cell immunity modulation by CD20+ cells depletion with rituximab, in association with maintenance immunosuppression including corticosteroids, tacrolimus and mycophenolate mofetil. The outcome in ABOi kidney transplantation have markedly improved over the years. In fact, although randomized trials are still lacking, recent meta analysis has revealed that there is no difference in terms of graft and patient’s survival between ABOi and ABO compatible kidney transplant, even in the long term. However, many concerns still exist, because ABOi kidney transplantation is associated with an increased risk of bleeding and infectious complications, partly related to the effects of extracorporeal treatments and the strong immunosuppression. Thus, a continuous improvement in desensitization strategies, with the aim of minimize the immunosuppressive burden, on the basis of immune pathogenesis, antibodies titers and/or ABO blood group, is warranted. In this review, we discuss the main immune mechanisms involved in ABOi kidney transplantation, the pathogenesis of tolerance and the desensitization regimens, including immunoadsorption and plasmapheresis and the immunosuppressive protocol. Finally, we provide an overview on outcome and future perspectives in ABOi kidney transplant.Keywords: ABO incompatible kidney transplant, blood group, plasma exchange, rituximab

Olga Baraldi,1 Francesca Bianchi,2,3 Viola Menghi,1 Andrea Angeletti,1 Anna Laura Croci Chiocchini,1 Maria Cappuccilli,1 Valeria Aiello,1 Giorgia Comai,1 Gaetano La Manna1 1Department of Experimental, Diagnostic and Specialty Medicine, Nephrology, Dialysis and Renal Transplant Unit, Sant’Orsola-Malpighi Hospital, University of Bologna, Bologna, 2Stem Wave Institute for Tissue Healing, Gruppo Villa Maria Care & Research – Ettore Sansavini Health Science Foundation, Lugo, Ravenna, 3National Institute of Biostructures and Biosystems at the Department of Experimental, Diagnostic and Specialty Medicine, Sant’Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy Background: Acute kidney injury, known as a major trigger for organ fibrosis and independent predictor of chronic kidney disease, is characterized by mesangial cell proliferation, inflammation and unbalance between biosynthesis and degradation of extracellular matrix. Therapeutic approaches targeting the inhibition of mesangial cell proliferation and matrix expansion may represent a promising opportunity for the treatment of kidney injury. An ester of hyaluronic acid and butyric acid (HB) has shown vasculogenic and regenerative properties in renal ischemic-damaged tissues, resulting in enhanced function recovery and minor degree of inflammation in vivo. This study evaluated the effect of HB treatment in mesangial cell cultures exposed to H2O2-induced oxidative stress.Materials and methods: Lactate dehydrogenase release and caspase-3 activation were measured using mesangial cells prepared from rat kidneys to assess necrosis and apoptosis. Akt and p38 phosphorylation was analyzed to identify the possible mechanism underlying cell response to HB treatment. The relative expressions of matrix metallopeptidase 9 (MPP-9) and collagen type 1 alpha genes were also analyzed by quantitative real-time polymerase chain reaction. Cell proliferation rate and viability were measured using thiazolyl blue assay and flow cytometry analysis of cell cycle with propidium iodide.Results: HB treatment promoted apoptosis of mesangial cells after H2O2-induced damage, decreased cellular proliferation and activated p38 pathway, increasing expression of its target gene MPP-9.Conclusion: This in vitro model shows that HB treatment seems to redirect mesangial cells toward apoptosis after oxidative damage and to reduce cell proliferation through p38 MAPK pathway activation and upregulation of MPP-9 gene expression involved in mesangial matrix remodeling. Keywords: acute kidney injury, apoptosis, hyaluronan ester of butyric acid, mesangial cells

Maria Cappuccilli,1 Gabriele Donati,1 Giorgia Comai,1 Olga Baraldi,1 Diletta Conte,1 Irene Capelli,1 Valeria Aiello,1 Andrea Pession,2 Gaetano La Manna1 1Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis, and Renal Transplant Unit, 2Molecular Laboratory of Pediatrics, Hematology–Oncology Unit, St Orsola Hospital, University of Bologna, Bologna, Italy Background: The aim of this study was the application of complementarity-determining region-3 spectratyping analysis to determine T-cell-repertoire complexity and to detect T-cell-clone expansion, as a measure of immune response in nonfunctioning kidney transplants (group hemodialysis-transplant [HD-Tx]), nontransplanted dialysis patients (group hemodialysis [HD]), and normal subjects as controls (group C).Patients and methods: Analysis of T-cell receptor (TCR) diversity by spectratyping was applied to peripheral blood samples collected from 21 subjects: eight in group HD-Tx, seven in group HD, and six in group C.Results: Considering the extent of the skew in TCR variable region repertoires as a measure of clonal T cells, we found that the number of altered spectra showed a progressive increase from normal subjects to dialysis patients and to nonfunctioning kidney transplants, respectively. Healthy subjects had the lowest number of altered spectra, and patients with nonfunctioning kidney transplants the highest. Differences were significant for group HD-Tx vs group C (P=0.017) and group HD vs group C (P=0.015), but not between nonfunctioning kidney-transplant recipients and dialysis patients (group HD-Tx vs group HD).Conclusion: Although dialysis appears to be a weaker trigger for clonal expansion of T cells, our data suggest that the utilization of complementarity-determining region-3 spectratyping analysis of the TCR repertoire might be useful to monitor specific immunoactivation in patients before and after kidney transplantation. Keywords: dialysis, nonfunctioning kidney transplant, T-cell repertoire, TCR spectratyping

Irene Capelli, Olga Baraldi, Giorgia Comai, Elisa Sala, Maria Cappuccilli, Chiara Donadei, Vania Cuna, Maria Laura Angelini, Gabriele Donati, Gaetano La Manna Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis and Renal Transplant Unit, St Orsola Hospital, University of Bologna, Bologna, Italy Background: Acute kidney injury occurring after kidney transplantation frequently leads to delayed graft function with detrimental long-term effects on graft survival. Neutrophil gelatinase-associated lipocalin (NGAL) has been validated as a biomarker for posttransplant acute kidney injury. This observational study aimed to assess the effectiveness of urinary NGAL as a predictive marker of delayed graft function.Materials and methods: Forty-three consecutive patients who received renal transplant were included in the study. Urine samples were collected before transplant (if available) and at days 1, 3, 7, 14, and 30 after transplant, and urinary NGAL levels were quantified by enzyme-linked immunosorbent assay.Results: Urinary NGAL progressively decreased after transplant in patients with both delayed and immediate graft function. However, urinary NGAL concentration remained significantly higher in the presence of delayed graft function in the first 14 days after transplant. The area under the receiver operating characteristic curve showed that the ability of urinary NGAL to predict delayed graft function was accurate at 1st and 3rd days after transplant.Conclusion: The relative decrease of urinary NGAL concentration rather than its absolute value may be relevant to predict delayed graft function after renal transplant. In particular, urinary NGAL area under the curve for 3 days seems to be a more valuable parameter of decision making in the early posttransplant period. Keywords: area under the curve, delayed graft function, immediate graft function, kidney transplant, NGAL, acute kidney injury

Renal allograft biopsy is the gold standard for the detection of histological lesions of chronic allograft dysfunction. The identification of a noninvasive routine test would be desirable. Elastosonography is used to assess tissue stiffness according to viscosity, and no data are available on the use of point quantification shear-wave elastography (ElastPQ) for the evaluation of renal chronic lesions.~Introduction~Background~To evaluate the feasibility of ElastPQ to assess cortical allograft stiffness and to determine the correlation of clinical, biological, and pathological factors with the diagnostic accuracy of kidney stiffness values in patients with histological lesions.~Research Question~Objective~Forty-two patients underwent kidney transplant biopsy and 10 valid measurements of ElastPQ, blindly performed by 2 operators. The interobserver reproducibility was assessed according to intraclass correlation coefficient. The ElastPQ measurements and the clinical data were compared using the Spearman correlation analysis.~Design~Methods~97.6% reliable measurements were obtained using ElastPQ, with an excellent interobserver agreement. The kidney stiffness was significantly higher in the patients with a time since transplantation >12 months and was correlated with chronic lesions (interstitial fibrosis, tubular atrophy transplant glomerulopathy, and mesangial matrix), with the interstitial fibrosis/tubular atrophy, score and with the sum of the scores of the chronic lesions. Mesangial matrix increase is the only independent determinant of kidney stiffness.~Results~Results~ElastPQ is a noninvasive, reproducible, and sensitive diagnostic tool able to detect moderate/severe chronic lesions. Its routine use during follow-up can identify patients eligible for biopsy, which remains the gold standard exam for detecting chronic allograft dysfunction.~Discussion~Conclusions [ABSTRACT FROM AUTHOR]