APPROCCIO ENDOVASCOLARE ALL’EMBOLIZZAZIONE NEL RENE TRAPIANTATO: DESCRIZIONE DELLA NOSTRA CASISTICA

Scopo: Descrivere la nostra casistica di pazienti nefrotrapiantati sottoposti ad embolizzazione arteriosa transcatetere. Materiali e metodi: Nel periodo 2016-2019, 7 pazienti (6 uomini, 1 donna; età media 57, range 46-66 anni) sono stati sottoposti ad embolizzazione transcatetere dopo trapianto renale: 3/7 prima dell’espianto chirurgico di un graft malfunzionante, 4/7 per complicanze vascolari insorte nel rene trapiantato (3 pseudoaneurismi, 1 fistola artero-venosa conseguente a biopsia del graft). Risultati: Le procedure pre-espianto sono state eseguite mediante posizionamento di spirali o plug metallici a cavallo dell’anastomosi chirurgica arteriosa. In tutti casi l’espianto chirurgico è stato eseguito senza complicanze emorragiche. Nei pazienti con pseudoaneurismi intrarenali l’embolizzazione è stata eseguita mediante posizionamento di spirali metalliche “a monte” e “a valle” dello pseudoaneurisma, per escluderlo dalla circolazione sistemica; 1 di queste procedure è stata eseguita in regime d’urgenza a causa della rottura dello pseudoaneurisma entro la pelvi renale. Nel paziente con fistola artero-venosa sono state posizionate microspirali metalliche entro l’arteria afferente la fistola. Nel caso eseguito in urgenza è stato necessaria una seconda procedura per il persistere dell’ematuria secondaria ad incompleta esclusione della sacca pseudoaneurismatica. In tutti i casi la procedura di embolizzazione ha determinato la risoluzione della problematica e la preservazione del graft. Conclusioni: Il trattamento endovascolare può essere un valido aiuto tanto nell’embolizzazione pre-espianto di graft renale quanto nel trattamento delle complicanze vascolari. In quest’ultimo caso l’embolizzazione dev’essere più precisa e selettiva possibile, per evitare l’embolizzazione non target con rischio di perdita di funzione del graft

Systemic and Nonrenal Adverse Effects Occurring in Renal Transplant Patients Treated with mTOR Inhibitors

The mammalian target of rapamycin inhibitors (mTOR-I), sirolimus and everolimus, are immunosuppressive drugs largely used in renal transplantation. The main mechanism of action of these drugs is the inhibition of the mammalian target of rapamycin (mTOR), a regulatory protein kinase involved in lymphocyte proliferation. Additionally, the inhibition of the crosstalk among mTORC1, mTORC2, and PI3K confers the antineoplastic activities of these drugs. Because of their specific pharmacological characteristics and their relative lack of nephrotoxicity, these inhibitors are valid option to calcineurine inhibitors (CNIs) for maintenance immunosuppression in renal transplant recipients with chronic allograft nephropathy. However, as other immunosuppressive drugs, mTOR-I may induce the development of several adverse effects that need to be early recognized and treated to avoid severe illness in renal transplant patients. In particular, mTOR-I may induce systemic nonnephrological side effects including pulmonary toxicity, hematological disorders, dysmetabolism, lymphedema, stomatitis, cutaneous adverse effects, and fertility/gonadic toxicity. Although most of the adverse effects are dose related, it is extremely important for clinicians to early recognize them in order to reduce dosage or discontinue mTOR-I treatment avoiding the onset and development of severe clinical complications

LC3B and ph-S6K are both expressed in epithelioid and classic renal angiomyolipoma: a rationale tissue-based evidence for combining use of autophagic and mTOR targeted drugs

Background: Targeted drugs to the autophagy processes are emerging in clinical trials. The aim of this work is to assess the magnitude of autophagic expression in renal angiomyolipoma. Methods: Fourteen cases of renal angiomyolipoma were recruited. Anti-LC3B-II and anti-phospho-S6K were detected by Western blot analysis. For immunohistochemical staining, sections were stained with the antibodies LC3B-II and cathepsin-K. LC3B-II was also analyzed by immunofluorescence. We have also carried out electron microscopy analysis on tumor cells. Results: 13 classic and 1 epithelioid renal angiomyolipoma were recruited. The Western-blot LC3B-II analysis shows increasing in protein expression in all cases, however quantitative protein expression ranged from 1 to 15 (mean 5). The autophagosome protein LC3B-I also significantly increased in all tumor extraction. The expression of LC3B-II protein was confirmed in tumoral samples by immunofluorescence. The lysosomal marker cathepsin-K was observed by immunohistochemistry on all tumours. The Western-blot ph-S6K analysis showed significant protein overexpression along all cases after evaluation of the quantitative S6K/Ponceaus ratio. In 6/14 (52%) the expression was high, with a quantitative increase of 653 fold induction in 4 angiomyolipoma compared to normal tissue. At electron microscopy, cancer cells evidenced round or oval electron-dense granules associated with membranes and granules with double membrane. Conclusion: Both autophagic LC3B-II and ph-S6K molecules are over-represented in both epithelioid and classic renal angiomyolipoma and a combined use of inhibitors to the autophagic and mTOR processes may be designed in clinical trials, when enrolling patients affected by tumours in tuberous sclerosis or angiomyolipoma at risk of bledding

Predictive model for delayed graft function based on easily available pre-renal transplant variables

Identification of pre-transplant factors influencing delayed graft function (DGF) could have an important clinical impact. This could allow clinicians to early identify dialyzed chronic kidney disease (CKD) patients eligible for special transplant programs, preventive therapeutic strategies and specific post-transplant immunosuppressive treatments. To achieve these objectives, we retrospectively analyzed main demographic and clinical features, follow-up events and outcomes registered in a large dedicated dataset including 2,755 patients compiled collaboratively by four Italian renal/transplant units. The years of transplant ranged from 1984 to 2012. Statistical analysis clearly demonstrated that some recipients' characteristics at the time of transplantation (age and body weight) and dialysis-related variables (modality and duration) were significantly associated with DGF development (p ≤ 0.001). The area under the receiver-operating characteristic (ROC) curve of the final model based on the four identified variables predicting DGF was 0.63 (95 % CI 0.61, 0.65). Additionally, deciles of the score were significantly associated with the incidence of DGF (p value for trend <0.001). Therefore, in conclusion, in our study we identified a pre-operative predictive model for DGF, based on inexpensive and easily available variables, potentially useful in routine clinical practice in most of the Italian and European dialysis units

Digital reporting of whole-slide images is safe and suitable for assessing organ quality in preimplantation renal biopsies

Digital pathology allows networks of "remote" specialist pathologists to report the findings of preimplantation kidney biopsies. We sought to validate the assessment of preimplantation kidney transplant biopsies for diagnostic purposes using whole-slide images according to the recommendations of the College of American Pathologists. Sixty-two consecutive, previously reported, preimplantation kidney biopsies were scanned using the ScanScope Digital Slide Scanner at 0.5 \u3bcm/pixel (20 7 objective). The slides were assessed for percent glomerulosclerosis, tubular atrophy, interstitial fibrosis and vascular narrowing using the Remuzzi criteria by two pathologists, one using glass slides and the other using the whole-slide images viewed on a widescreen computer monitor. After a 2-week washout period, all of the slides were re-assessed by the same pathologists using the opposite mode of reporting to that used in the first evaluation. Very high glass-digital intraobserver concordance was achieved for the overall score and for individual grades by both pathologists (\u3ba range, 0.841-0.973). The overall scores obtained by both pathologists and using both methods were identical. The times needed to assess the biopsies were 14 minutes when using a light microscope and 18 minutes, including scanning time, which averaged 2 minutes 20 seconds per slide, when using digital microscopy. Digital microscopy is a reliable, fast, and safe method for the assessment of preimplantation kidney biopsies

Advantages of Using a Web-based Digital Platform for Kidney Preimplantation Biopsies

Background: In the setting of kidney transplantation, histopathology of kidney biopsies is a key element in the organ assessment and allocation. Despite the broad diffusion of the Remuzzi-Karpinski score on preimplantation kidney biopsies, scientific evidence of its correlation to the transplantation outcome is controversial. The main issues affecting the prognostic value of histopathology are the referral to general on-call pathologists and the semiquantitative feature of the score, which can raise issues of interpretation. Digital pathology has shown very reliable and effective in the oncological diagnosis and treatment; however, the spread of such technologies is lagging behind in the field of transplantation. The aim of our study was to create a digital online platform where whole-slide images (WSI) of preimplantation kidney biopsies could be uploaded and stored. Methods: We included 210 kidney biopsies collected between January 2015 and December 2019 from the joint collaboration of the transplantation centers of Padua and Verona. The selected slides, stained with hematoxylin and eosin, were digitized and uploaded on a shared web platform. For each case, the on-call pathologists' Remuzzi grades were obtained from the original report, together with the clinical data and the posttransplantation follow-up. Results: The storage of WSI of preimplantation kidney biopsies would have several clinical, scientific, and educational advantages. The clinical utility relies on the possibility to consult online expert pathologists and real-time quality checks of diagnosis. From the perspective of follow-up, the archived digitized biopsies can offer a useful comparison to posttransplantation biopsies. In addition, the digital online platform is a precious tool for multidisciplinary meetings aimed both at the clinical discussion and at the design of research projects. Furthermore, this archive of readily available WSI is an important educational resource for the training of professionals. Conclusions: Finally, the web platform lays the foundation for the introduction of artificial intelligence in the field of transplantation that would help create new diagnostic algorithms and tools with the final aim of increasing the precision of organ assessment and its predictive value for transplant outcome

Incidence and clinical predictors of primary opportunistic deep cutaneous mycoses in solid organ transplant recipients: a multicenter cohort study

Primary opportunistic deep cutaneous fungal infections may cause significant morbidity and mortality in solid organ transplant recipients (OTR), but no data exist about their incidence, timing, and clinical predictors in a long-term follow-up. Patients and methods: A series of 3293 consecutive OTR including 1991 kidney, 929 heart, and 373 liver transplant recipients were enrolled. Patients were regularly followed up since time at transplantation (mean 5.5 yr ±5.9 SD) and primary opportunistic fungal infections registered. Persons-year at risk (PYs), incidence rates (IR), incidence rate ratios (IRR), and 95% confidence intervals were computed. Results: Twenty-two cases of deep cutaneous mycoses were detected, (IR 1.2 cases per 1000 PYs) after a mean follow-up time since transplantation of 2.5 yr ± 2.0 SD (median 1.8 yr). Six patients had subsequent systemic involvement and three patients died of systemic dissemination. A higher risk for mycoses was observed in the first two yr after transplantation, (IRR 35.9, p &lt; 0.0001), in renal transplant recipients (IRR 5.1 p = 0.030), and in patients transplanted after the age of 50 (IRR 11.5 p = 0.020). Conclusions: Primary deep cutaneous opportunistic mycoses in OTR occur mainly in the first two yr after transplantation, in renal transplant recipients, and in older patients. © 2009 John Wiley &amp; Sons A/S

Histopathology and Long-Term Outcome of Kidneys Transplanted From Donors With Severe Acute Kidney Injury

Background: Acute kidney injury is a treatable entity although difficult to recognize without diagnostic biopsy.We investigated the potential association between clinically defined deceased donors and acute kidney injury with preimplantation histological findings and recipient outcomes. Methods: Kidney biopsies from donors were classified using the Acute Kidney Injury Network criteria and assessed for percentage glomerulosclerosis, tubular atrophy, interstitial fibrosis, and vascular narrowing with the Remuzzi score and for acute tubular necrosis. Differences in incidence rates of delayed graft function (DGF) and cumulative rejection episodes were compared between recipients transplanted with normal and 3 levels of acute kidney injury using the analysis of variance with Bonferroni correction (P \ubc .0012). Results: Sixteen out of 335 donors showed a severe acute kidney injury level 3 with a median serum creatinine of 458 mmol/L. Fourteen (88%) had 0-3 Remuzzi score and were used for single kidney transplantation and 2 (12%) were used for dual kidney transplantation (score: 4-6). Recipients who received a kidney from a donorwith level 3 acute kidney injury had a higher percentage ofDGF (47%) without statistical significance (P \ubc .008). The rate of cumulative rejection (45%) at 2 years was not significantly increased (P \ubc .09). Conclusions: Recipients receiving level 3 acute kidney injury kidneys, selected with Remuzzi histopathological score and acute tubular necrosis assessment, had a greater incidence of DGF but a similar long-term cumulative rejection compared to no injury and level 1 and level 2 acute kidney injury donors. The application of the histopathological examination allowed expansion of the kidney donor pool