A Machine Learning-Driven Virtual Biopsy System For Kidney Transplant Patients.

In kidney transplantation, day-zero biopsies are used to assess organ quality and discriminate between donor-inherited lesions and those acquired post-transplantation. However, many centers do not perform such biopsies since they are invasive, costly and may delay the transplant procedure. We aim to generate a non-invasive virtual biopsy system using routinely collected donor parameters. Using 14,032 day-zero kidney biopsies from 17 international centers, we develop a virtual biopsy system. 11 basic donor parameters are used to predict four Banff kidney lesions: arteriosclerosis, arteriolar hyalinosis, interstitial fibrosis and tubular atrophy, and the percentage of renal sclerotic glomeruli. Six machine learning models are aggregated into an ensemble model. The virtual biopsy system shows good performance in the internal and external validation sets. We confirm the generalizability of the system in various scenarios. This system could assist physicians in assessing organ quality, optimizing allograft allocation together with discriminating between donor derived and acquired lesions post-transplantation.

Overcoming limits: First ABO incompatible living donor paired kidney transplant in an hypersensitized pediatric recipient in Spain.

INTRODUCTION: HLA sensitization is a growing problem in children awaiting kidney transplantation. In some cases, finding an immunologically compatible donor entails contemplating the option of an ABO incompatible transplant or paired transplant. METHODS: Patient with genetic nephrotic syndrome and progressive chronic kidney disease, with a previous thrombosis of a first kidney transplant, resulting hypersensitized and remaining for a long-time on hemodialysis. Despite a desensitization strategy, family members were incompatible and deceased donation options must be ruled out due to the presentation of donor-specific antibodies (DSA). After 4 years, the possibility arises to perform a kidney paired transplant with a 62-year-old woman with an incompatible blood group. Although the current cytotoxicity- and cell-based crossmatches were negative, history of DSA were recorded. RESULTS: An intensive ABO and HLA desensitization protocol was performed in order to combat the isohemagglutinin antibodies and on the memory-HLA, based on rituximab, apheresis sessions, and immunoglobulins. Despite the donor being older in terms of pediatric transplantation, the donor-recipient weight difference, and immunological risk, the transplant was completed successfully. Maintenance of titration of up to 1/2 was confirmed after 3 weeks post-transplant (IgM and IgG). Kidney biopsy at 2 weeks and 6 months without signs of rejection. The patient is currently 12 months post-transplant and has not presented any signs of transplant rejection and has proper renal function. CONCLUSIONS: Kidney paired transplantation is an excellent solution for hypersensitized children, and ABO incompatibility can be considered to increase their options to find a good donor, without thereby obtaining worse results.

Outcomes after 20 years of experience in minimally invasive living-donor nephrectomy.

INTRODUCTION: The transperitoneal laparoscopic approach is considered the gold standard technique for living kidney donation. Other accepted laparoscopic techniques include the retroperitoneal approach, natural orifice transluminal endoscopic surgery (NOTES)-assisted, laparo-endoscopic single-site surgery (LESS), with excellent results in the donor and graft. Many studies have compared these techniques with open ones. Our objective is to describe our experience and results in minimally invasive living-donor nephrectomies (MILDN): laparoscopic, NOTES-assisted, and LESS since their introduction in March 2002. MATERIALS AND METHODS: We conducted a retrospective observational study of donors undergoing MILDN between March 2002 and March 2020. RESULTS: A total of 714 MILDNs were performed at our centre. All were completed, except for one, because of recipient death. The conventional laparoscopic approach was used in 541 cases (75.88%), NOTES in 116 (16.9%), LESS in 55 (7.7%), and one mini open (0.14%). Two-thirds of the donors were females (478 cases). The mean donor age was 52.87 years (SD 10.93). Six donors (0.8%) were diagnosed beforehand with a small renal mass, which was removed before transplantation in bench surgery. The right kidney was removed in 17.8% of cases. Warm ischaemia time was higher in the NOTES and LESS groups. We had eight conversions. The global intraoperative and postoperative complication rates were 6.8% and 4.9%, respectively. None of the donors developed renal disease during follow-up (mean 3.68 years). Five-year recipient and graft survival rates were 98.8% and 96.8%, respectively. CONCLUSIONS: MILDN techniques are safe for donors and grafts, with low complication.

Influence of Persistent Inflammation in Follow-Up Biopsies After Antibody-Mediated Rejection in Kidney Transplantation.

Background: Despite recent advances in immunosuppression treatment, antibody-mediated rejection (ABMR) remains the leading cause of kidney graft loss. Information about prognostic markers and the efficacy of treatment is scarce. Methods: Retrospective study with kidney recipients diagnosed an active ABMR from January 1, 2004 to December 31, 2019 to explore the influence of persistent inflammation in follow-up biopsies on graft survival after ABMR treatment. Results: About 116 patients were included. Active ABMR were treated with a combination of plasma exchange (PE), intravenous immunoglobulin (IVIg), rituximab, and steroids. At 6 months of treatment, 63 (54.3%) patients presented a stabilization or improvement in kidney-graft function. The effectiveness varied depending on the timepoint of the presentation between transplantation and rejection, which is lower for those with late ABMR (63 vs. 21% for early vs. late ABMR, respectively). Ninety patients (77%) underwent a control biopsy after ABMR treatment, from which 46 (51%) responded to the treatment. Microvascular inflammation (MVI) persisted in 64 (71%) biopsies, whereas tubulitis persisted in 17 (19%) biopsies. Death-censored graft survival at 1 year was significantly lower in patients with persistent MVI (86% vs. 95% without persistent MVI, P = 0.002), or with persistent tubulitis (44% vs. 66% without tubulitis, P = 0.02). In the Cox Regression analysis, the persistence of MVI [hazard ratio (HR), 4.50 (95%CI, 1.35-14.96), P = 0.01] and tubulitis [HR 2.88 95%CI (1.24-6.69), P = 0.01) in follow-up biopsies significantly increased the risk of graft failure. Conclusion: Persistent inflammation in follow-up biopsies after ABMR treatment was associated with an increased risk of graft loss, even without meeting Banff rejection criteria. Study Registration: Agencia Española de Medicamentos y Productos Sanitarios (AEMPS): 14566/RG 24161. Study code: UTRINM-2017-01.

Outcomes From Brain Death Donors With Previous Cardiac Arrest Accepted for Pancreas Transplantation: A Single-center Retrospective Analysis.

OBJECTIVE: The aim of the study was to evaluate the effect of cardiac arrest time (CAT) in donors after brain death (DBD) donors on pancreas transplant outcome. SUMMARY OF BACKGROUND DATA: Results from donors after circulatory death report good outcomes despite warm ischemia times up to 57 minutes. Previous cardiac arrest in DBD has been addressed as a potential risk factor, but duration of the CAT has never been evaluated. METHODS: We conducted a retrospective analysis including 342 pancreas transplants performed at our center from 2000 to 2016, and evaluated the effect of previous cardiac arrest in DBD (caDBD) on pancreas transplant outcomes. RESULTS: A total of 49 (14.3%) caDBD were accepted for transplantation [median CAT of 5.0 min (IQR 2.5-15.0)]. Anoxic encephalopathy was most frequent and P-PASS higher (16.9 vs 15.6) in caDBD group when compared with other DBD. No differences were found in all other characteristics evaluated.Graft survival was similar between both groups, as was the incidence of early graft failure (EGF). CAT increased the risk for EGF [OR 1.09 (95% CI, 1.01-1.17)], and the duration of CPR discriminated for EGF [AUC of 0.86 (95% CI, 0.74-0.98)], with a sensitivity and specificity of 100% and 75% at a cutoff of 15 minutes. When evaluated separately, caDBD >15 min increased over 5 times the risk for EGF [HR 5.80 (95% CI, 1.82-18.56); P = 0.003], and these presented fewer days on the ICU (1.0 vs 3.0 d). CONCLUSION: CaDBD donors are suitable for routine pancreas transplantation without increasing EGF risk, and in those with longer CAT it may be prudent to postpone donation a few days to allow a thorough evaluation of organ damage following cardiac arrest.

B Cell-Derived Extracellular Vesicles Reveal Residual B Cell Activity in Kidney Graft Recipients Undergoing Pre-Transplant Desensitization.

Background: Living-donor kidney transplant (LDKT) recipients undergoing desensitization for Human Leukocyte Antigen (HLA)-incompatibility have a high risk of developing antibody-mediated rejection (ABMR). The purpose of the study is to evaluate if residual B cell activity after desensitization could be estimated by the presence of circulating B cell-derived extracellular vesicles (BEVs). Methods: BEVs were isolated by Sepharose-based size exclusion chromatography and defined as CD19+ and HLA-II+ extracellular vesicles. We analyzed stored serum samples from positive crossmatch LDKT recipients before and after desensitization at first post-transplant biopsy and at 12-month protocol biopsy (n = 11). Control groups were formed by hypersensitized patients who were not submitted to desensitization (n = 10) and by low-risk recipients (n = 9). A prospective validation cohort of 11 patients also included the analysis of B cells subpopulations in recipients' blood and lymph nodes recovered upon graft implantation, along with BEVs analysis before and after desensitization. Results: We found out that CD19+ and HLA-II+BEVs dropped significantly after desensitization and relapse in patients who later developed ABMR was evident. We validated these findings in a proof-of-concept prospective cohort of 6 patients who received the same desensitization protocol and also in a control group of 5 LDKT recipients. In these patients, B cell subpopulations were also studied in recipients' blood and lymph nodes that were recovered before the graft implantation. We confirmed the significant drop in BEVs after desensitization and that this paralleled the reduction in CD19+cells in lymph nodes, while in peripheral blood B cells, this change was almost undetectable. Conclusions: BEVs reflected B cell residual activity after desensitization and this could be a valid surrogate of humoral alloreactivity in this setting.

The impact of functional delayed graft function in the modern era of kidney transplantation - A retrospective study.

The dialysis-based definition of Delayed Graft Function (dDGF) is not necessarily objective as it depends on the individual physician's decision. The functional definition of DGF (fDGF, the failure of serum creatinine to decrease by at least 10% daily on 3 consecutive days during the first week post-transplant), may be more sensitive to reflect recovery after the ischemia-reperfusion injury. We retrospectively analyzed both definitions in 253 deceased donor kidney transplant recipients for predicting death-censored graft failure as primary outcome, using eGFR < 25 ml/min/1.73 m2 as a surrogate end-point for graft failure. Secondary outcome was a composite outcome that included graft failure as above and also patient's death. Median follow-up was 3.22 [2.38-4.21] years. Seventy-nine patients developed dDGF (31.2%) and 127 developed fDGF (50.2%). Sixty-three patients fulfilled criteria for both definitions (24.9%). At multivariable analysis, the two definitions were significantly associated with the primary [HR (95%CI) 2.07 (1.09-3.94), P = 0.026 for fDGF and HR (95%CI) 2.41 (1.33-4.37), P = 0.004 for dDGF] and the secondary composite outcome [HR (95%CI) 1.58 (1.01-2.51), P = 0.047 for fDGF and HR (95%CI) 1.67 (1.05-2.66), P = 0.028 for dDGF]. Patients who met criteria for both definitions had the worst prognosis, with a three-year estimates (95%CI) of survival from the primary and secondary outcomes of 2.31 (2.02-2.59) and 2.20 (1.91-2.49) years for fDGF+/dDGF+, in comparison with the other groups (P < 0.01 for trend). fDGF provides supplementary information about graft outcomes on top of the dDGF definition in a modern series of kidney transplantation.

COVID-19 in transplant recipients: The Spanish experience.

We report the nationwide experience with solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients diagnosed with coronavirus disease 2019 (COVID-19) in Spain until 13 July 2020. We compiled information for 778 (423 kidney, 113 HSCT, 110 liver, 69 heart, 54 lung, 8 pancreas, 1 multivisceral) recipients. Median age at diagnosis was 61 years (interquartile range [IQR]: 52-70), and 66% were male. The incidence of COVID-19 in SOT recipients was two-fold higher compared to the Spanish general population. The median interval from transplantation was 59 months (IQR: 18-131). Infection was hospital-acquired in 13% of cases. No donor-derived COVID-19 was suspected. Most patients (89%) were admitted to the hospital. Therapies included hydroxychloroquine (84%), azithromycin (53%), protease inhibitors (37%), and interferon-ß (5%), whereas immunomodulation was based on corticosteroids (41%) and tocilizumab (21%). Adjustment of immunosuppression was performed in 85% of patients. At the time of analysis, complete follow-up was available from 652 patients. Acute respiratory distress syndrome occurred in 35% of patients. Ultimately, 174 (27%) patients died. In univariate analysis, risk factors for death were lung transplantation (odds ratio [OR]: 2.5; 95% CI: 1.4-4.6), age >60 years (OR: 3.7; 95% CI: 2.5-5.5), and hospital-acquired COVID-19 (OR: 3.0; 95% CI: 1.9-4.9).

Psychosocial risk factors for impaired health-related quality of life in living kidney donors: results from the ELIPSY prospective study.

Living kidney donors' follow-up is usually focused on the assessment of the surgical and medical outcomes. Whilst the psychosocial follow-up is advocated in literature. It is still not entirely clear which exact psychosocial factors are related to a poor psychosocial outcome of donors. The aim of our study is to prospectively assess the donors' psychosocial risks factors to impaired health-related quality of life at 1-year post-donation and link their psychosocial profile before donation with their respective outcomes. The influence of the recipient's medical outcomes on their donor's psychosocial outcome was also examined. Sixty donors completed a battery of standardized psychometric instruments (quality of life, mental health, coping strategies, personality, socio-economic status), and ad hoc items regarding the donation process (e.g., motivations for donation, decision-making, risk assessment, and donor-recipient relationship). Donors' 1-year psychosocial follow-up was favorable and comparable with the general population. So far, cluster-analysis identified a subgroup of donors (28%) with a post-donation reduction of their health-related quality of life. This subgroup expressed comparatively to the rest, the need for more pre-donation information regarding surgery risks, and elevated fear of losing the recipient and commitment to stop their suffering.

Impact of Discards for Living Donor Kidney Transplantation in a Transplant Program.

OBJECTIVE: Living donor kidney transplantation (LDKT) is the best treatment for end-stage renal disease. In this setting, a significant percentage of transplants are not undertaken because of medical and nonmedical reasons of both donors and recipients. However, the impact of these discards in a transplant program has not been identified thoroughly so far. Our objective was to clarify key reasons for exclusion of LDKTs and the consequences for the discarded transplant candidates in the following 5 years. METHODS: Analysis of donors' and recipients' characteristics of 781 couples evaluated in our hospital from January 2005 to December 2013. The consequences of discards in transplant candidates were analyzed in the cohort 2012 to 2013 (n = 106) and followed up until October 2018. RESULTS: In our study group, 402 (51.5%) LDKT couples were successfully donated, and 379 (48.5%) were excluded. Donor and transplant recipient candidates discarded were older at the evaluation (55.07 ± 12.14 years vs 51.73 ± 10.93 years, P < .001; 48.81 ± 14.05 years vs 44.62 ± 13.91 years, P < .001, respectively). The most frequent reason for kidney discard was medical contraindication found in the potential donor (47.5%; low eGFR, diabetes mellitus, impaired glucose tolerance, high blood pressure, cardiovascular pathology casually found during evaluation, and proteinuria). Of the discarded candidates from 2012 to 2013, 36.8% received a deceased donor kidney transplant, 17% a LDKT with another donor, 7.5% stayed on the waiting list, 18.9% died, 3.8% were excluded from the waiting list, and 14.2% were lost to follow-up. CONCLUSIONS: In most cases, transplantation was not undertaken because of donor pathology. Fifty-three percent of the discarded patients were eventually transplanted, with a 31.4% probability to receive an organ from another living donor.

Effect of immunosuppression in miRNAs from extracellular vesicles of colorectal cancer and their influence on the pre-metastatic niche.

Colorectal cancer (CRC) occurs with more aggressiveness in kidney transplant recipients compared to the general population. Immunosuppressive therapy plays a crucial role in the development of post-transplant malignancy. Concretely, cyclosporine A (CsA) has intrinsic pro-oncologic properties, while several studies report a regression of cancer after the introduction of rapamycin (RAPA). However, their effect on the extracellular vesicle (EV) content from CRC cell lines and their relevance in the pre-metastatic niche have not yet been studied. Here, we investigated the effect of RAPA and CsA in EV-miRNAs from metastatic and non-metastatic CRC cell lines and the role of relevant miRNAs transferred into a pre-metastatic niche model. EV-miRNA profiles showed a significant upregulation of miR-6127, miR-6746-5p, and miR-6787-5p under RAPA treatment compared to CsA and untreated conditions in metastatic cell lines that were not observed in non-metastatic cells. From gene expression analysis of transfected lung fibroblasts, we identified 22 shared downregulated genes mostly represented by the histone family involved in chromatin organization, DNA packaging, and cell cycle. These results suggest that EV-miR-6127, miR-6746-5p and miR-6787-5p could be a potential epigenetic mechanism induced by RAPA therapy in the regulation of the pre-metastatic niche of post-transplant colorectal cancer.

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

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

The development of a predictive model of graft function in uncontrolled donors after circulatory death: validity of a pulsatile renal preservation machine cut-off value for kidney acceptance.

BACKGROUND: The criteria for kidney suitability in uncontrolled donors after circulatory death (uDCD) procured after regional normothermic perfusion are based on macroscopic appearance and renal haemodynamic values with final renal resistance (FRR). However, these criteria have not been analysed to predict the future graft function. This study presents a model to predict the outcome in uDCD kidneys and define the predictive FRR value. METHODS: All uDCD kidney transplants performed in our hospital from 2004 to 2016 were included. Donors and recipients and pre-transplantation data are described. The endpoint was glomerular filtration rate (GFR) ≥30 mL/min at 6 months after transplantation. RESULTS: A total of 194 recipients were included. FRR in donors ≥60 years old was (mean ± SD) 0.27 ± 0.11 versus 0.22 ± 0.09 mmHg/mL/min in donors <60 years (P = 0.042). Kidney survival was 88.2% versus 84% at 12 months and 60.7% versus 30.8% at 120 months (P = 0.067). For the group of recipients from donors ≥60 years, the FRR was 0.37 ± 0.08 mmHg/mL/min in the GFR <30 mL/min group versus 0.18 ± 0.06 mmHg/mL/min in the GFR ≥30 mL/min group (P < 0.001). The value FRR ≥0.3 mmHg/mL/min predicts 59-79% of GFR <30 mL/min [odds ratio = 2.16, 95% confidence interval (CI) 1.80-6.40; P < 0.001]. The predictive accuracy of FRR for GFR by ROC curve was 0.968 (95% CI). The best cut-off for FRR was 0.3 mmHg/mL/min to predict GFR at 6 months with a sensitivity of 67%, specificity of 100%, positive predictive value of 83% and negative predictive value of 92%. CONCLUSIONS: Our results suggest that in uDCD donors the combination of donor age ≥60 years together with FRR ≥0.3 mmHg/mL/min could predict poor outcome at 6 months after transplantation in low immunological risk recipients.

Rituximab, plasma exchange and immunoglobulins: an ineffective treatment for chronic active antibody-mediated rejection.

BACKGROUND: Chronic active antibody-mediated rejection (c-aABMR) is an important cause of allograft failure and graft loss in long-term kidney transplants. METHODS: To determine the efficacy and safety of combined therapy with rituximab, plasma exchange (PE) and intravenous immunoglobulins (IVIG), a cohort of patients with transplant glomerulopathy (TG) that met criteria of active cABMR, according to BANFF'17 classification, was identified. RESULTS: We identified 62 patients with active c-aABMR and TG (cg ≥ 1). Twenty-three patients were treated with the combination therapy and, 39 patients did not receive treatment and were considered the control group. There were no significant differences in the graft survival between the two groups. The number of graft losses at 12 and 24 months and the decline of eGFR were not different and independent of the treatment. A decrease of eGFR≥13 ml/min between 6 months before and c-aABMR diagnosis, was an independent risk factor for graft loss at 24 months (OR = 5; P = 0.01). Infections that required hospitalization during the first year after c-aABMR diagnosis were significantly more frequent in treated patients (OR = 4.22; P = 0.013), with a ratio infection/patient-year of 0.65 and 0.20 respectively. CONCLUSIONS: Treatment with rituximab, PE, and IVIG in kidney transplants with c-aABMR did not improve graft survival and was associated with a significant increase in severe infectious complications. TRIAL REGISTRATION: Agencia Española de Medicametos y Productos Sanitarios (AEMPS): 14566/RG 24161. Study code: UTR-INM-2017-01.

Everolimus with Reduced Calcineurin Inhibitor Exposure in Renal Transplantation.

Background Everolimus permits reduced calcineurin inhibitor (CNI) exposure, but the efficacy and safety outcomes of this treatment after kidney transplant require confirmation.Methods In a multicenter noninferiority trial, we randomized 2037 de novo kidney transplant recipients to receive, in combination with induction therapy and corticosteroids, everolimus with reduced-exposure CNI (everolimus arm) or mycophenolic acid (MPA) with standard-exposure CNI (MPA arm). The primary end point was treated biopsy-proven acute rejection or eGFR<50 ml/min per 1.73 m2 at post-transplant month 12 using a 10% noninferiority margin.Results In the intent-to-treat population (everolimus n=1022, MPA n=1015), the primary end point incidence was 48.2% (493) with everolimus and 45.1% (457) with MPA (difference 3.2%; 95% confidence interval, -1.3% to 7.6%). Similar between-treatment differences in incidence were observed in the subgroups of patients who received tacrolimus or cyclosporine. Treated biopsy-proven acute rejection, graft loss, or death at post-transplant month 12 occurred in 14.9% and 12.5% of patients treated with everolimus and MPA, respectively (difference 2.3%; 95% confidence interval, -1.7% to 6.4%). De novo donor-specific antibody incidence at 12 months and antibody-mediated rejection rate did not differ between arms. Cytomegalovirus (3.6% versus 13.3%) and BK virus infections (4.3% versus 8.0%) were less frequent in the everolimus arm than in the MPA arm. Overall, 23.0% and 11.9% of patients treated with everolimus and MPA, respectively, discontinued the study drug because of adverse events.Conclusions In kidney transplant recipients at mild-to-moderate immunologic risk, everolimus was noninferior to MPA for a binary composite end point assessing immunosuppressive efficacy and preservation of graft function.

Complement-Activating Anti-HLA Antibodies in Kidney Transplantation: Allograft Gene Expression Profiling and Response to Treatment.

Complement-activating anti-HLA donor-specific antibodies (DSAs) are associated with impaired kidney transplant outcome; however, whether these antibodies induce a specific rejection phenotype and influence response to therapy remains undetermined. We prospectively screened 931 kidney recipients for complement-activating DSAs and used histopathology, immunostaining, and allograft gene expression to assess rejection phenotypes. Effector cells were evaluated using in vitro human cell cultures. Additionally, we assessed the effect of complement inhibition on kidney allograft rejection phenotype and the clinical response to complement inhibition in 116 independent kidney recipients with DSAs at transplant receiving rejection prophylaxis with eculizumab or standard of care (plasma exchange and intravenous Ig) at ten international centers. The histomolecular rejection phenotype associated with complement-activating DSA was characterized by complement deposition and accumulation of natural killer cells and monocytes/macrophages in capillaries and increased expression of five biologically relevant genes (CXCL11, CCL4, MS4A7, MS4A6A, and FCGR3A) indicative of endothelial activation, IFNγ response, CD16-mediated natural killer cell activation, and monocyte/macrophage activation. Compared with standard of care, eculizumab specifically abrogated this histomolecular rejection phenotype and associated with a decreased 3-month rejection incidence rate in patients with complement-activating DSAs (56%; 95% confidence interval [95% CI], 38% to 74% versus 19%; 95% CI, 8% to 35%; P=0.001) but not in those with noncomplement-activating DSAs (9%; 95% CI, 2% to 25% versus 13%; 95% CI, 2% to 40%; P=0.65). In conclusion, circulating complement-activating anti-HLA DSAs are associated with a specific histomolecular kidney allograft rejection phenotype that can be abrogated by complement inhibition.

Regional differences in the management and outcome of kidney transplantation in patients with human immunodeficiency virus infection: A 3-year retrospective cohort study.

BACKGROUND: In the developed world, kidney transplantation (KT) in patients with human immunodeficiency virus (HIV) infection is well established. Developing countries concentrate 90% of the people living with HIV, but their experience is underreported. Regional differences may affect outcomes. OBJECTIVES: We compared the 3-year outcomes of patients with HIV infection receiving a KT in two different countries, in terms of incomes and development. METHODS: This was an observational, retrospective, double-center study, including all HIV-infected patients >18 years old undergoing KT. RESULTS: Between 2005 and 2015, 54 KTs were performed (39 in a Brazilian center, and 15 in a Spanish center). Brazilians had less hepatitis C virus co-infection (5% vs 27%, P=.024). Median cold ischemia time was higher in Brazil (25 vs 18 hours, P=.001). Biopsy-proven acute rejection (AR) was higher in Brazil (33% vs 13%, P=.187), as were the number of AR episodes (22 vs 4, P=.063). Patient survival at 3 years was 91.3% in Brazil and 100% in Spain; P=.663. All three cases of death in Brazil were a result of bacterial infections within the first year post transplant. At 3 years, survival free from immunosuppressive changes was lower in Brazil (56% vs 90.9%, P=.036). Raltegravir-based treatment to avoid interaction with calcineurin inhibitor was more prevalent in Spain (80% vs 3%; P<.001). HIV infection remained under control in all patients, with undetectable viral load and no opportunistic infections. CONCLUSION: Important regional differences exist in the demographics and management of immunosuppression and antiretroviral therapy. These details may influence AR and infectious complications. Non-AIDS infections leading to early mortality in Brazil deserve special attention.

Histopathological evaluation of pretransplant donor biopsies in expanded criteria donors with high kidney donor profile index: a retrospective observational cohort study.

There is no consensus on the allocation of renal transplants from expanded criteria donors (ECD). The Kidney Donor Profile Index (KDPI) is used without the need for pretransplant donor biopsies (PTDB). We explored whether PTDB based on Remuzzi Score (RS) allows identification of those marginal kidneys in the highest calculated KDPI risk group (>91%) that appropriate for single transplantation. A retrospective study was conducted of 485 consecutive kidneys procured from a single center and transplanted if the RS was ≤4. We compared 5-year kidney and patients survival between KDPI groups and between RS <4 or =4 in the highest KDPI group. The median KDPI (interquartile range) was 71 (66-76) for KDPI <80% (n = 77), 86 (81-90) for KDPI 81-90% (n = 82), and 97 (94-100) for KDPI >91% (n = 205). Patient survival at 5 years was 85.7%, 85.3%, and 76.09% (P = 0.058) and death-censored graft survival was 84.4%, 86.5%, 73.6% (P = 0.015), respectively for each KDPI group. In >91% calculated KDPI group, there were no differences in graft survival depending on the RS (<4 vs. =4) (P = 0.714). The implementation of PTDB based on RS used for allocation of organs with the highest KDPI range could support to the acceptance of suitable organs for single transplantation with good patient and graft survival rate.

Trasplante renal grupo sanguíneo ABO incompatible. Experiencia colaborativa inédita España y Perú / Incompatible ABO blood group renal transplant. Unprecedented collaborative experience between Spain and Peru

La incompatibilidad de grupo sanguíneo ABO y la sensibilización al HLA constituyen grandes barreras a vencer en pro de la óptima utilización de riñones de donante vivo. Describimos en nuestro medio el primer trasplante renal exitoso ABO incompatible en un paciente de 24 años, retrasplantado renal, altamente sensibilizado (PRA: 89%) y sin opción alguna en disponer de donantes cadavéricos ni familiares. Sin embargo, su único donante vivo HLA compatible era de grupo sanguíneo A incompatible con el grupo O del receptor. El paciente requirió de un régimen precondicionante consistente en recambios plasmáticos, rituximab, imunoglobulina y terapia inmunosupresora cuádruple, a fin de reducir los títulos elevados de isoaglutininas anti A de 1:128 a niveles de seguridad de 1:8, para el éxito del trasplante. Este fue realizado en Coordinación con la Unidad de Trasplante Renal del Hospital Clínic de Barcelona España (HCB). La ausencia de rechazo mediado por isoaglutininas muestra el potencial beneficio del protocolo al remover los anticuerpos anti grupo sanguíneo. A los dos años del trasplante, la función renal se mantiene estable con niveles de creatinina 1,5 mg%. Concluimos que el trasplante renal ABO incompatible (ABOi) es opción viable para pacientes cuyo único donante sea grupo sanguíneo incompatible, y entre nosotros representa esperanzadora fuente de órganos.

ABO blood group incompatibility and HLA sensitization are major barriers that need to be overcome in order to make optimum use of kidneys from living donors possible. We report the first successful ABO- incompatible kidney transplant in a 24-year old, highly sensitized (panel reactive antibodies (PRA) 89% kidney retransplantation patient, who lacked any option to get a cadaveric or family donor. However, the patient's sole HLA-compatible living donor had group A blood incompatible with the recipient's O blood group. The < patient required a pre-conditioning regime that consisted of plasma exchange, rituximab, immunoglobulin, and quadruple immunosuppressive therapy in order to reduce high titers of anti-A isoagglutinins from 1:128 to a safe level of 1:8, for successful transplant. This was performed in coordination with the Renal Transplant Unit of Hospital Clinic de Barcelona (HCB), Spain. Absence of rejection mediated by isoagglutinins shows the potential benefit of a protocol consisting in removing antibodies from the anti-blood group. Two yearsafter transplantation, the kidney function remains stable, with creatinine levels of 1.5 mg%. We conclude that an ABO-incompatible kidney transplant is a viable option for patients whose only donor has blood of an incompatible blood group and for us this represents a hope-inspiring source of organs .

Role of HHV-8 and mTOR pathway in post-transplant Kaposi sarcoma staging.

Kaposi's sarcoma (KS) is one of the most frequent transplant related tumors. Several pathways are involved; however, the impact of the molecular phenotype associated to the tumor stage and the behavior-depending resultant therapy is still unknown. The aim of our study was to analyze the role of HHV-8 and mTOR pathway in tumor stages of skin KS after renal transplantation. Twelve renal transplant recipients with cutaneous KS from five transplant centers (1980-2007) under reduction of immunosuppression or conversion to mTOR inhibitor were included. The expression of HHV-8, PTEN, TGFß, VEGF, phospho-mTOR, and phospho-P70S6K in tumoral tissue was analyzed. KS lesions were classified as patch, plaque, and nodule state. HHV-8 infection was found in all tissue samples. KS lesions showed high activation of VEGF, p-mTOR and p-P70S6K, low PTEN, and null TGFß expression. The only pathway activated in a staging-dependent manner was mTOR with higher p-mTOR and p-P70S6K expression in nodule versus patch stage. KS lesions disappeared after 5.24 months in all converted patients without any recurrence in 14.05 years of mean follow-up. The activation of mTOR pathway according to KS stages supports the rational of the mTOR inhibitor in post-transplant Kaposi.