Factor B Inhibition with Iptacopan in Recurrent C3 Glomerulopathy Following Kidney Transplant: A Report of Two Cases.

C3 glomerulopathy is a rare disease caused by fluid phase dysregulation of the alternative complement pathway. Currently, treatment depends on clinical and histological severity and includes nephroprotection, unspecific immunosuppression, and terminal complement blockers (C5), without having an etiological treatment approved. C3 glomerulopathy has high recurrence rates after kidney transplantation with a high risk of graft loss. Fortunately, new molecules are being developed that specifically target the proximal alternative complement pathway, such as iptacopan, a factor B inhibitor that showed promising results in native kidneys and cases of transplant recurrence in a phase 2 clinical trial. We present 2 "real-world" cases of C3 glomerulopathy recurrence in kidney allografts treated with iptacopan, with initial excellent clinical response and safety profile, especially with early introduction. We also present follow-up biopsies that showed no C3 deposition during factor B inhibition. Our cases suggest that proximal blockade of the alternative complement pathway can be effective and safe in the treatment of C3 glomerulopathy recurrence in kidney transplantation, bringing other questions such as dual blockade (eg, in C3 and C5), the optimal patient profile to benefit from factor B inhibition or treatment duration and its potential use in other forms of membranoproliferative glomerulonephritis (eg, immune complex-mediated).

Long-Term Outcomes of Incidental Liver Malignancies in Simultaneous Liver-Kidney Transplant Recipients.

BACKGROUND: The pretransplant diagnosis of liver malignancies in nodular cirrhotic livers remains a diagnostic challenge despite current advances. Although the prognostic impact of incidental hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (iCC) in liver transplant recipients is well documented, there are no data on the impact in simultaneous liver kidney transplant (LKT) recipients. METHODS: This is a single-center observational, retrospective study of all LKT performed from May 1993 to April 2022. Among these patients, demographic data, immunosuppressive therapy, rejection episodes, and prevalence of incidental HCC or iCC were evaluated. RESULTS: One hundred eight LKTs were performed and 6 were excluded. There were 13 patients with incidental carcinomas in the explanted liver: one of them with both an HCC and iCC, one with an iCC, and the remaining with an HCC. One case of iCC died. No other recurrences occurred. There were no cases of incidental HCC nor iCC in patients with a hereditary or metabolic LKT indication. We found no differences in the 5-year patient survival, and death-censored kidney and liver graft survival rates for those LKT with an incidental HCC and those without it (76.9% vs 84.2%, P = .5; 100% vs 91.6%, P = .28; and 100% vs 94.7%, P = 0.39, respectively). Finally, there were no significant associations between explant carcinoma and rejections of the liver (7.7% vs 17.9%, P = .34) or kidney graft (0% vs 16.8%, P = 0.11). CONCLUSION: Despite a high prevalence of incidental HCC or iCC, patient, kidney, and liver graft 5-year survival were unaffected by incidental HCC.

Challenges in perioperative blood transfusions in kidney transplantation and the need for Patient Blood Management.

BACKGROUND: Anemia is highly prevalent in end-stage chronic kidney disease patients, increasing their risk of receiving blood transfusions during and on the days after a kidney transplant (KTx) surgery. However, there is currently a lack of data that thoroughly describes this phenomenon in this population, the associated risk factors, and how they could benefit from the application of Patient Blood Management (PBM) guidelines. MATERIALS AND METHODS: Observational study. All adult patients who received a KTx between January 1st, 2020, and December 31st, 2021, were included and followed up to six months after transplantation. Those who received a multiorgan transplant, whose data was missing in the electronic health records, and who had primary non-function were excluded. We recorded donor and recipient characteristics, cold ischemia time, preoperative hemoglobin concentration, iron status deficiency biomarkers, incidence of delayed graft function and biopsy-proven graft rejections, and graft function at discharge and 6 months after transplantation. RESULTS: We found that a high amount (39%) of KTx recipients required at least one blood transfusion during the perioperative period. And that 1) most of these patients had anemia at the time of transplantation (85.4%), 2) iron status upon admission was associated with the transfusion of more blood units (3.9 vs 2.7, p=0.019), 3) surgical reintervention (OR 7.28, 2.35-22.54) and deceased donor donation (OR 1.99, 1.24-3.21) were associated with an increased risk of transfusion, and finally, 4) there was an association between a higher number of blood units transfused and impaired kidney graft function six months after hospital discharge (1.6 vs 1.9, p=0.02). CONCLUSIONS: In conclusion, PBM guidelines should be applied to patients on the KTx deceased donor waiting list and especially those scheduled to receive a transplant from a living donor. This could potentially increase the utilization efficiency of blood products and avoid transfusion-related severe adverse effects.

Early kinetics of donor-derived cell-free DNA after transplantation predicts renal graft recovery and long-term function.

BACKGROUND: Ischemia-reperfusion injury (IRI) upon transplantation is one of the most impactful events that the kidney graft suffers during its life. Its clinical manifestation in the recipient, delayed graft function (DGF), has serious prognostic consequences. However, the different definitions of DGF are subject to physicians' choices and centers' policies, and a more objective tool to quantify IRI is needed. Here, we propose the use of donor-derived cell-free DNA (ddcfDNA) for this scope. METHODS: ddcfDNA was assessed in 61 kidney transplant recipients of either living or deceased donors at 24 h, and 7, 14 and 30 days after transplantation using the AlloSeq cfDNA Kit (CareDx, San Francisco, CA, USA). Patients were followed-up for 6 months and 7-year graft survival was estimated through the complete and functional iBox tool. RESULTS: Twenty-four-hour ddcfDNA was associated with functional DGF [7.20% (2.35%-15.50%) in patients with functional DGF versus 2.70% (1.55%-4.05%) in patients without it, P = .023] and 6-month estimated glomerular filtration rate (r = -0.311, P = .023). At Day 7 after transplantation, ddcfDNA was associated with dialysis duration in DGF patients (r = 0.612, P = .005) and worse 7-year iBox-estimated graft survival probability (ß -0.42, P = .001) at multivariable analysis. Patients with early normalization of ddcfDNA (<0.5% at 1 week) had improved functional iBox-estimated probability of graft survival (79.5 ± 16.8%) in comparison with patients with 7-day ddcfDNA ≥0.5% (67.7 ± 24.1%) (P = .047). CONCLUSIONS: ddcfDNA early kinetics after transplantation reflect recovery from IRI and are associated with short-, medium- and long-term graft outcome. This may provide a more objective estimate of IRI severity in comparison with the clinical-based definitions of DGF.

Outcome of Kidney Transplants from Viremic and Non-Viremic Hepatitis C Virus Positive Donors into Negative Recipients: Results of the Spanish Registry.

Historically, donor infection with hepatitis-C virus (HCV) has been a barrier to kidney transplantation. However, in recent years, it has been reported that HCV positive kidney donors transplanted into HCV negative recipients offer acceptable mid-term results. However, acceptance of HCV donors, especially viremic, has not broadened in the clinical practice. This is an observational, multicenter, retrospective study including kidney transplants from HCV positive donors into negative recipients reported to the Spanish group from 2013 to 2021. Recipients from viremic donors received peri-transplant treatment with direct antiviral agents (DAA) for 8-12 weeks. We included 75 recipients from 44 HCV non-viremic donors and 41 from 25 HCV viremic donors. Primary non function, delayed graft function, acute rejection rate, renal function at the end of follow up, and patient and graft survival were not different between groups. Viral replication was not detected in recipients from non-viremic donors. Recipient treatment with DAA started pre-transplant avoids (n = 21) or attenuates (n = 5) viral replication but leads to non-different outcomes to post-transplant treatment with DAA (n = 15). HCV seroconversion was more frequent in recipients from viremic donors (73% vs. 16%, p < 0.001). One recipient of a viremic donor died due to hepatocellular carcinoma at 38 months. Donor HCV viremia seems not to be a risk factor for kidney transplant recipients receiving peri-transplant DAA, but continuous surveillance should be advised.

Preemptive simultaneous pancreas kidney transplantation has survival benefit to patients.

Several organ allocation protocols give priority to wait-listed simultaneous kidney-pancreas (SPK) transplant recipients to mitigate the higher cardiovascular risk of patients with diabetes mellitus on dialysis. The available information regarding the impact of preemptive simultaneous kidney-pancreas transplantation on recipient and graft outcomes is nonetheless controversial. To help resolve this, we explored the influence of preemptive simultaneous kidney-pancreas transplants on patient and graft survival through a retrospective analysis of the OPTN/UNOS database, encompassing 9690 simultaneous transplant recipients between 2000 and 2017. Statistical analysis was performed applying a propensity score analysis to minimize bias. Of these patients, 1796 (19%) were transplanted preemptively. At ten years, recipient survival was significantly superior in the preemptive group when compared to the non-preemptive group (78.9% vs 71.8%). Dialysis at simultaneous kidney-pancreas transplantation was an independent significant risk for patient survival (hazard ratio 1.66 [95% confidence interval 1.32-2.09]), especially if the dialysis duration was 12 months or longer. Preemptive transplantation was also associated with significant superior kidney graft survival compared to those on dialysis (death-censored: 84.3% vs 75.4%, respectively; estimated half-life of 38.57 [38.33 -38.81] vs 22.35 [22.17 - 22.53] years, respectively). No differences were observed between both groups neither for pancreas graft survival nor for post-transplant surgical complications. Thus, our results sustain the relevance of early referral for pancreas transplantation and the importance of pancreas allocation priority in reducing patient mortality after simultaneous kidney-pancreas transplantation.

Donor-derived Cell-free DNA Shows High Sensitivity for the Diagnosis of Pancreas Graft Rejection in Simultaneous Pancreas-kidney Transplantation.

BACKGROUND: Pancreas graft status in simultaneous pancreas-kidney transplant (SPKTx) is currently assessed by nonspecific biochemical markers, typically amylase or lipase. Identifying a noninvasive biomarker with good sensitivity in detecting early pancreas graft rejection could improve SPKTx management. METHODS: Here, we developed a pilot study to explore donor-derived cell-free DNA (dd-cfDNA) performance in predicting biopsy-proven acute rejection (P-BPAR) of the pancreas graft in a cohort of 36 SPKTx recipients with biopsy-matched plasma samples. dd-cfDNA was measured using the Prospera test (Natera, Inc.) and reported both as a fraction of the total cfDNA (fraction; %) and as concentration in the recipient's plasma (quantity; copies/mL). RESULTS: In the absence of P-BPAR, dd-cfDNA was significantly higher in samples collected within the first 45 d after SPKTx compared with those measured afterward (median, 1.00% versus 0.30%; median, 128.2 versus 35.3 cp/mL, respectively with both; P = 0.001). In samples obtained beyond day 45, P-BPAR samples presented a significantly higher dd-cfDNA fraction (0.83 versus 0.30%; P = 0.006) and quantity (81.3 versus 35.3 cp/mL; P = 0.001) than stable samples. Incorporating dd-cfDNA quantity along with dd-cfDNA fraction outperformed dd-cfDNA fraction alone to detect active rejection. Notably, when using a quantity cutoff of 70 cp/mL, dd-cfDNA detected P-BPAR with a sensitivity of 85.7% and a specificity of 93.7%, which was more accurate than current biomarkers (area under curve of 0.89 for dd-cfDNA (cp/ml) compared with 0.74 of lipase and 0.46 for amylase). CONCLUSIONS: dd-cfDNA measurement through a simple noninvasive blood test could be incorporated into clinical practice to help inform graft management in SPKTx patients.

Outcomes in older kidney recipients from older donors: A propensity score analysis.

Background: The age of patients referred for kidney transplantation has increased progressively. However, the precise influence of age on transplant outcomes is controversial. Methods: Etrospective study in which graft and recipient survival were assessed in a cohort of ≥75 years old kidney recipients and compared with a contemporary younger one aged 60-65 years through a propensity score analysis. Results: We included 106 recipients between 60-65 and 57 patients of ≥75 years old with a median follow-up of 31 [13-54] months. Unadjusted one- and five-year recipient survival did not significantly differ between the older (91% and 74%) and the younger group (95% and 82%, P=0.06). In the IPTW weighted Cox regression analysis, recipient age was not associated with an increased risk of death (HR 1.88 95%CI [0.81-4.37], P=0.14). Unadjusted one- and five-year death-censored graft survival did not significantly differ between both groups (96% and 83% for the older and 99% and 89% for the younger group, respectively, P=0.08). After IPTW weighted Cox Regression analysis, recipient age ≥75 years was no associated with an increased risk of graft loss (HR 1.95, 95%CI [0.65-5.82], P=0.23). Conclusions: These results suggest that recipient age should not be considered itself as an absolute contraindication for kidney transplant.

Antiphospholipase A2 receptor antibody-positive membranous nephropathy in the kidney donor: Lessons from a serendipitous transplantation.

Primary membranous nephropathy (PMN) is an autoimmune disease limited to the kidney that is characterized by the presence of circulating PLAR2 antibodies in 70% of the cases and usually positivity for PLA2R and IgG4 by immunohistochemistry (IHC) staining. We report the first documented case of PMN (PLA2R positive) in a deceased kidney donor, transplanted to two different recipients and their clinical and immunological evolution through serial biopsies. Recipient A's first allograft biopsy (Day 26) was compatible with a MN with both positive PLA2R and IgG4 subepithelial deposits in IHC. The donor's preimplantation kidney biopsies were retrieved and reexamined, revealing MN, with high intensity for PLA2R and IgG4 in IHC. Recipient B's protocol allograft biopsy, performed later at 3 months, also revealed histology compatible with MN but without the presence of PLA2R nor IgG4 in IHC. At 1-year follow-up, both recipients maintain graft function. Serial protocol biopsies were performed in both patients showing disappearance of IgG4 in recipient A but the persistence of PLA2R in IHC. We can conclude that, given the reversal of PMN changes in the grafts, it could be considered to transplant a patient from an asymptomatic deceased donor with PMN as long as he maintains unaltered renal function.

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.

Impact of insulin therapy before donation on graft outcomes in pancreas transplantation: An analysis of the OPTN/UNOS database.

AIMS: Information on the impact of insulin therapy before pancreas donation on pancreas outcomes is scarce. We aim to explore the influence of insulin therapy before donation on recipient and pancreas graft survival. METHODS: Registry study including 12,841 pancreas recipients from the OPTN/UNOS registry performed between 2000 and 2017. Inverse probability of treatment weighting (IPTW) was used to account for covariate imbalance between recipients from a donor with and without insulin requirements. RESULTS: A total of 7765 (60%) patients received a pancreas from a donor with insulin before donation (IBD). Pancreas graft survival (death-censored) was similar between recipients from IBD and non-IBD donors at 1, 5 and 10 years (89% vs 89%, 78% vs 79 and 69% vs 70%, respectively, P = 0.35). Recipients from IBD donors presented a similar 90-days pancreas graft survival. After IPTW weighting, IBD donors were neither associated with any post-transplant surgical complication (HR 1.11 [95% CI 0.98-1.24], P = 0.06), nor with risk for recipient death (HR 0.94 [95% CI 0.85-1.04], P = 0.26), nor pancreas graft failure (HR 1.06 [95% CI 0.98-1.16], P = 0.15). CONCLUSIONS: Insulin therapy before donation in accepted pancreas donors was not associated, per se, with an impaired pancreas graft and patient survival.

Protocol for Optimizing the Use of Kidneys From Donors With Seropositivity for Hepatitis C Virus in Seronegative Recipients.

BACKGROUND: The rapid identification of the viral load from hepatitis C virus (HCV) in seropositive donors enables the determination of their infection capacity and the subsequent design of a strategy to optimize the use of direct-action antivirals (DAA) in seronegative recipients. In 2017, we designed an optimization protocol; this study aims to assess its efficacy and safety. METHODS: This is a prospective, multicenter observational study that complies with the Declarations of Helsinki and Istanbul. Donors were HCV seropositive. The HCV and human immunodeficiency virus loads were immediately determined in the donors. For viremic donors, recipients were treated with DAA for 8 weeks. For nonviremic donors, DAA was started if a viral load was detected during the follow-up period. The minimum follow-up period was 6 months posttransplant. RESULTS: This study recruited 28 donors. Just over half of the donors (n = 15; 53.5%) had a nonactive history of injection drug use. Eight (22.4%) donors were viremic, and 20 (87.6%) were nonviremic; 13 (65%) had been treated previously. Nine grafts were ineligible for the protocol. We performed a total of 47 transplants. Procedure I (viremic donors) was performed in 13 recipients (27.7%). Posttransplant viremia was observed in 6 participants. Posttransplant viremia was low (<100 IU/mL) in 4 participants but high (36,000 and 138,000 IU/mL) in 2 participants who had initiated DAA after the transplant; all these patients had a sustained viral response. Seroconversion was observed in 11 of 13 (84.6%) patients. Procedure II (nonviremic donors) was undertaken in 34 (82.3%) patients. No positive viral loads were observed. Seroconversion occurred in 7 of 34 (20.5%) recipients. All recipients maintained kidney function at 6 months posttransplant, except 1 patient with a graft that had never been functional and another patient who died of pancreatitis. Both patients had received kidneys from nonviremic donors. CONCLUSIONS: Our experience supports the efficacy and safety of this protocol.

There Are 33,784 Functioning Kidney Grafts in Spain: Who Monitors Them and How?

BACKGROUND: As of December 31, 2018, Spain's National Transplant Organization estimated that there were 61,764 people under renal replacement therapy across the country. Of this population, 33,784 (54.7%) had a functioning kidney graft. METHODS: Through the use of a survey to all Spanish hospitals involved in kidney transplantations, we studied the distribution of these recipients nationally, along with who was monitoring them and how. Data collected include the ratio of recipients to transplant nephrologists, median number of recipients followed in each center, and median number of transplant nephrologists per hospital. Of the 806 centers in the Spanish hospital network, 43 (5.3%) were involved in kidney transplants, including 39 transplant hospitals and 4 associated hospitals. The median number of transplants per center was 800 (interquartile range [IQR] = 510-1200). There were 3 nephrologists (IQR 2-5), and the ratio of recipients to transplant nephrologists was 270 (IQR = 190-323). RESULTS: There were no significant differences in these data between autonomous communities, except in the case of the Canary Islands, which had a significantly lower ratio of recipients to transplant nephrologists (146; IQR = 100-185) compared with the rest of the country (ratio 277; IQR = 207-329; P < .001). Of the 39 hospitals, 29 (74.4%) referred patients to centers that did not perform transplants. CONCLUSIONS: All in all, few Spanish hospitals perform kidney transplants. The ratio of recipients to transplant nephrologists is very high, compelling most hospitals to refer patients to nontransplant hospitals for follow-up. There are important differences in the distribution of recipients in hospitals in the Canary Islands vs the rest of the country, a difference that is undoubtedly attributable to its geographic peculiarities.

Kidney Transplantation in Monoclonal Immunoglobulin Deposition Disease: A Report of 6 Cases.

Monoclonal immunoglobulin deposition disease (MIDD) usually leads to kidney failure. Treatment of patients with a bortezomib-based regimen followed by autologous stem cell transplantation (SCT) has been increasingly used, with improvements in the response rates and allograft outcomes in kidney transplant recipients. The objective of this report was to analyze the outcomes of 6 patients who underwent kidney transplantation in our institution after treatment of MIDD between 2010 and 2019. Monoclonal immunoglobulin deposition disease was initially treated with bortezomib-based therapy followed by high-dose melphalan and autologous SCT with complete hematologic response, although all patients remained on dialysis. During a median follow-up of 20.5 months from kidney transplant (54 months from SCT), 1 patient experienced hematologic relapse and 2 had hematologic progression (one of them with MIDD relapse in the allograft) requiring treatment. The patient with organ relapse received daratumumab monotherapy, achieving complete hematologic response but with graft failure. The other 5 patients had functional grafts with median serum creatinine 1.68 mg/dL. These results support that, in patients with MIDD and sustained complete hematologic response, a kidney transplant can be considered. The optimal approach to treatment of hematologic relapse or recurrence of MIDD after kidney transplant remains to be determined.

Mucormycosis associated with COVID-19 in two kidney transplant patients.

Coronavirus disease 2019 (COVID-19) predisposes patients to bacterial and fungal superinfections due to the impairment of the immunological system. Among the associated opportunistic fungal infections, mucormycosis is one of the least frequent but with the highest mortality. We describe two cases of mucormycosis in two kidney transplant recipients, while they were hospitalized for SARS-CoV-2 pneumonia, with rhinosinusal and musculoskeletal involvement, respectively.

A hybrid data envelopment analysis-artificial neural network prediction model for COVID-19 severity in transplant recipients.

In an overwhelming demand scenario, such as the SARS-CoV-2 pandemic, pressure over health systems may outburst their predicted capacity to deal with such extreme situations. Therefore, in order to successfully face a health emergency, scientific evidence and validated models are needed to provide real-time information that could be applied by any health center, especially for high-risk populations, such as transplant recipients. We have developed a hybrid prediction model whose accuracy relative to several alternative configurations has been validated through a battery of clustering techniques. Using hospital admission data from a cohort of hospitalized transplant patients, our hybrid Data Envelopment Analysis (DEA)-Artificial Neural Network (ANN) model extrapolates the progression towards severe COVID-19 disease with an accuracy of 96.3%, outperforming any competing model, such as logistic regression (65.5%) and random forest (44.8%). In this regard, DEA-ANN allows us to categorize the evolution of patients through the values of the analyses performed at hospital admission. Our prediction model may help guiding COVID-19 management through the identification of key predictors that permit a sustainable management of resources in a patient-centered model. Supplementary Information: The online version contains supplementary material available at 10.1007/s10462-021-10008-0.

A case of recurrent anemia due to chronic parvovirus B19 infection in a kidney transplant recipient. Can everolimus make a difference?

Parvovirus B19 (PB19) is a common infection among solid transplant recipients. Usually, it is asymptomatic, but sometimes it can become a real therapeutic challenge. We report a case of a kidney transplant recipient with relapsing pure red cell aplasia due to PB19 infection. Our patient was initially managed with standard treatment consisting of intravenous immunoglobulins and minimization of immunosuppressive treatment. However, when this approach became ineffective, conversion from tacrolimus to everolimus was done, with favorable results. This paper explores infection by PB19 in kidney transplant recipients and the potential benefits of a calcineurin inhibitor-free immunosuppression and the antiviral properties of mTOR inhibitors.

Increasing kidney grafts for transplantation.

INTRODUCTION: The current pool of organs available for transplantation does not cover requirements, for this reason non-standard risk donors need to be incorporated into the pool. In this way, donors with small renal tumour are considered for transplantation after bench tumour excision. The aim of our study was to analyse our experience in using these grafts for transplantation. MATERIALS AND METHODS: Retrospective analysis from our prospective accrued database of donors with incidental renal mass used for kidney transplantation between January 2007 and August 2018. RESULTS: Twenty kidney transplantations were performed, thirteen cases received the affected kidney (after tumour removal) and seven the contralateral kidney; from six living and eleven deceased donors. Donor and recipient median age was 58 years (range 22-82) and 56.5 years (range 38-74), respectively. Mean tumour diameter was 12.7 mm (SD 9.5). Tumours resulted in two benign lesions and fifteen renal cell carcinoma. Surgical margins were negative. Two cases presented with bleeding after reperfusion was solved without repercussion. One case presented with immediate vein thrombosis. None of them present delayed graft function. After a 69 month follow-up none of the donors or the recipients presented tumour recurrence. CONCLUSIONS: Kidneys with small incidental tumours seem to be a good option for kidney transplantation in selected patients after bench surgery excision with good functional and oncologic results. More studies and longer follow-up are needed to confirm these results.