Efficacy and safety of oral fosfomycin for asymptomatic bacteriuria in kidney transplant recipients: Results from a Spanish multicenter cohort.

Current guidelines recommend against systematic screening or treating asymptomatic bacteriuria (AB) among kidney transplant (KT) recipients, although the evidence regarding episodes occurring early after transplantation or in the presence of anatomical abnormalities is inconclusive. Oral fosfomycin may constitute a good option for the treatment of post-transplant AB, particularly due to the emergence of multidrug-resistant (MDR) uropathogens. Available clinical evidence supporting its use in this specific setting, however, remains scarce. We performed a retrospective study in 14 Spanish institutions from January 2005 to December 2017. Overall, 137 episodes of AB diagnosed in 133 KT recipients treated with oral fosfomycin (calcium and trometamol salts) with a test-of-cure urine culture within the first 30 days were included. Median time from transplantation to diagnosis was 3.1 months (interquartile range [IQR]: 1.1 - 10.5). Most episodes (96.4% [132/137]) were caused by gram-negative bacteria (GNB), and 56.9% (78/137) were categorized as MDR (extended-spectrum ß-lactamase-producing Enterobacterales [20.4%] and carbapenem-resistant GNB [2.9%]). Rate of microbiological failure at month 1 was 40.1% (95% confidence interval [95%CI]: 31.9 - 48.9) for the whole cohort and 42.3% (95%CI: 31.2 - 54.0) for episodes due to MDR pathogens. Previous urinary tract infection (odds ratio [OR]: 2.42; 95%CI: 1.11 - 5.29; P-value = 0.027) and use of fosfomycin as salvage therapy (OR: 8.31; 95%CI: 1.67 - 41.35; P-value = 0.010) were predictors of microbiological failure. No severe treatment-related adverse event were detected. Oral fosfomycin appears to be a suitable and safe alternative for the treatment (if indicated) of AB after KT, including those episodes due to MDR uropathogens.

Immunoguided Discontinuation of Prophylaxis for Cytomegalovirus Disease in Kidney Transplant Recipients Treated With Antithymocyte Globulin: A Randomized Clinical Trial.

BACKGROUND: Antiviral prophylaxis is recommended in cytomegalovirus (CMV)-seropositive kidney transplant (KT) recipients receiving antithymocyte globulin (ATG) as induction. An alternative strategy of premature discontinuation of prophylaxis after CMV-specific cell-mediated immunity (CMV-CMI) recovery (immunoguided prevention) has not been studied. Our aim was to determine whether it is effective and safe to discontinue prophylaxis when CMV-CMI is detected and to continue with preemptive therapy. METHODS: In this open-label, noninferiority clinical trial, patients were randomized 1:1 to follow an immunoguided strategy, receiving prophylaxis until CMV-CMI recovery or to receive fixed-duration prophylaxis until day 90. After prophylaxis, preemptive therapy (valganciclovir 900 mg twice daily) was indicated in both arms until month 6. The primary and secondary outcomes were incidence of CMV disease and replication, respectively, within the first 12 months. Desirability of outcome ranking (DOOR) assessed 2 deleterious events (CMV disease/replication and neutropenia). RESULTS: A total of 150 CMV-seropositive KT recipients were randomly assigned. There was no difference in the incidence of CMV disease (0% vs 2.7%; P = .149) and replication (17.1% vs 13.5%; log-rank test, P = .422) between both arms. Incidence of neutropenia was lower in the immunoguided arm (9.2% vs 37.8%; odds ratio, 6.0; P < .001). A total of 66.1% of patients in the immunoguided arm showed a better DOOR, indicating a greater likelihood of a better outcome. CONCLUSIONS: Prophylaxis can be prematurely discontinued in CMV-seropositive KT patients receiving ATG when CMV-CMI is recovered since no significant increase in the incidence of CMV replication or disease is observed. CLINICAL TRIALS REGISTRATION: NCT03123627.

Pretransplant CMV-Specific T-Cell Immunity But Not Dose of Antithymocyte Globulin Is Associated With Recovery of Specific Immunity After Kidney Transplantation.

BACKGROUND: This is a prospective, multicenter, observational study in cytomegalovirus (CMV)-seropositive kidney transplant recipients with pretransplant CMV-specific cell-mediated immunity (CMV-CMI) receiving antithymocyte globulin (ATG). We aimed to investigate posttransplant CMV-CMI over time and the impact of the dose-dependent ATG. METHODS: CMV-CMI was assessed at days +30, +45, +60, and +90 after transplantation with the QuantiFERON-CMV assay. A reactive result (interferon-γ [IFN-γ] ≥ 0.2 IU/mL) indicated a positive CMV-CMI. RESULTS: A total of 78 positive CMV-CMI patients were enrolled in the study, of which 59.5% had a positive CMV-CMI at day +30 and 82.7% at day +90. Multivariate logistic regression analysis showed that ATG dose was not associated with positive CMV-CMI at any point. However, pretransplant IFN-γ level (>12 IU/mL vs ≤12 IU/mL) was associated with positive CMV-CMI at day +30 (odds ratio, 12.9; 95% confidence interval, 3.1-53.3; P < .001). In addition, all the patients who did not recover CMV-CMI at day +90 had a pretransplant IFN-γ level ≤12 IU/mL. CONCLUSIONS: More than half of CMV-seropositive kidney transplant recipients receiving ATG recover (or maintain) CMV-CMI by the first month after transplantation. The pretransplant IFN-γ level, but not the ATG dose, shows a strong association with the kinetics of this recovery.

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).

Oral fosfomycin for the treatment of lower urinary tract infections among kidney transplant recipients-Results of a Spanish multicenter cohort.

Oral fosfomycin may constitute an alternative for the treatment of lower urinary tract infections (UTIs) in kidney transplant recipients (KTRs), particularly in view of recent safety concerns with fluroquinolones. Specific data on the efficacy and safety of fosfomycin in KTR are scarce. We performed a retrospective study in 14 Spanish hospitals including KTRs treated with oral fosfomycin (calcium and trometamol salts) for posttransplant cystitis between January 2005 and December 2017. A total of 133 KTRs developed 143 episodes of cystitis. Most episodes (131 [91.6%]) were produced by gram-negative bacilli (GNB), and 78 (54.5%) were categorized as multidrug resistant (including extended-spectrum ß-lactamase-producing Enterobacteriaceae [14%] or carbapenem-resistant GNB [3.5%]). A median daily dose of 1.5 g of fosfomycin (interquartile range [IQR]: 1.5-2) was administered for a median of 7 days (IQR: 3-10). Clinical cure (remission of UTI-attributable symptoms at the end of therapy) was achieved in 83.9% (120/143) episodes. Among those episodes with follow-up urine culture, microbiological cure at month 1 was achieved in 70.2% (59/84) episodes. Percutaneous nephrostomy was associated with a lower probability of clinical cure (adjusted odds ratio: 10.50; 95% confidence interval: 0.98-112.29; P = 0.052). In conclusion, fosfomycin is an effective orally available alternative for treating cystitis among KTRs.

Use of tocilizumab in kidney transplant recipients with COVID-19.

Acute respiratory distress syndrome associated with coronavirus infection is related to a cytokine storm with large interleukin-6 (IL-6) release. The IL-6-receptor blocker tocilizumab may control the aberrant host immune response in patients with coronavirus disease 2019 (COVID-19) . In this pandemic, kidney transplant (KT) recipients are a high-risk population for severe infection and showed poor outcomes. We present a multicenter cohort study of 80 KT patients with severe COVID-19 treated with tocilizumab during hospital admission. High mortality rate was identified (32.5%), related with older age (hazard ratio [HR] 3.12 for those older than 60 years, P = .039). IL-6 and other inflammatory markers, including lactic acid dehydrogenase, ferritin, and D-dimer increased early after tocilizumab administration and their values were higher in nonsurvivors. Instead, C-reactive protein (CRP) levels decreased after tocilizumab, and this decrease positively correlated with survival (mean 12.3 mg/L in survivors vs. 33 mg/L in nonsurvivors). Each mg/L of CRP soon after tocilizumab increased the risk of death by 1% (HR 1.01 [confidence interval 1.004-1.024], P = .003). Although patients who died presented with worse respiratory situation at admission, this was not significantly different at tocilizumab administration and did not have an impact on outcome in the multivariate analysis. Tocilizumab may be effective in controlling cytokine storm in COVID-19 but randomized trials are needed.

Pre-transplant assessment of pp65-specific CD4 T cell responses identifies CMV-seropositive patients treated with rATG at risk of late onset infection.

Assessment of CMV-specific T cell immunity might be a useful tool in predicting CMV infection after solid organ transplantation. We have investigated CD4 and CD8 T-cell responses to CMV pp65 and IE-1 antigens in a prospective study of 28 CMV-seropositive kidney transplant recipients who were administered lymphocyte-depleting antibodies (Thymoglobulin®) as induction treatment and with universal prophylaxis for CMV infection. The response was analyzed by intracellular flow cytometry analysis of IFN-γ production in pretransplant samples and at 1, 6, 12 and 24 months post-transplant. Overall, only pretransplant CD4 T-cell responses to pp65 were significantly lower (p = .004) in patients with CMV replication post-transplant. ROC curve analysis showed that pre-transplant frequencies of pp65-specific CD4 + T cells below 0.10% could predict CMV infection with 75% sensitivity and 83.33% specificity (AUC: 0.847; 95% CI: 0.693-1.001; p = .0054) and seem to be mandatory for efficient control of CMV viral replication by the host immune system. In conclusion, the functional assessment of CMV-specific CD4 T-cell immunity pretransplant in seropositive patients may allow the identification of Thymoglobulin®-treated kidney transplant recipients at risk of developing CMV infection post-transplantation.

Tubulo-interstitial inflammation increases the risk of graft loss after the recurrence of IgA nephropathy.

Background: Immunoglobulin A nephropathy (IgAN) is the most frequent recurrent disease in kidney transplant recipients and its recurrence contributes to reducing graft survival. Several variables at the time of recurrence have been associated with a higher risk of graft loss. The presence of clinical or subclinical inflammation has been associated with a higher risk of kidney graft loss, but it is not precisely known how it influences the outcome of patients with recurrent IgAN. Methods: We performed a multicentre retrospective study including kidney transplant recipients with biopsy-proven recurrence of IgAN in which Banff and Oxford classification scores were available. 'Tubulo-interstitial inflammation' (TII) was defined when 't' or 'i' were ≥2. The main endpoint was progression to chronic kidney disease (CKD) stage 5 or to death censored-graft loss (CKD5/DCGL). Results: A total of 119 kidney transplant recipients with IgAN recurrence were included and 23 of them showed TII. Median follow-up was 102.9 months and 39 (32.8%) patients reached CKD5/DCGL. TII related to a higher risk of CKD5/DCGL (3 years 18.0% vs 45.3%, log-rank 7.588, P = .006). After multivariate analysis, TII remained related to the risk of CKD5/DCGL (HR 2.344, 95% CI 1.119-4.910, P = .024) independently of other histologic and clinical variables. Conclusions: In kidney transplant recipients with IgAN recurrence, TII contributes to increasing the risk of CKD5/DCGL independently of previously well-known variables. We suggest adding TII along with the Oxford classification to the clinical variables to identify recurrent IgAN patients at increased risk of graft loss who might benefit from intensified immunosuppression or specific IgAN therapies.

Management of immunosuppressive therapy in kidney transplant recipients with COVID-19. A multicentre national study derived from the Spanish Society of Nephrology COVID registry.

INTRODUCTION: SARS CoV2 infection has had a major impact on renal transplant patients with a high mortality in the first months of the pandemic. Intentional reduction of immunosuppressive therapy has been postulated as one of the cornerstone in the management of the infection in the absence of targeted antiviral treatment. This has been modified according to the patient`s clinical situation and its effect on renal function or anti-HLA antibodies in the medium term has not been evaluated. OBJECTIVES: Evaluate the management of immunosuppressive therapy made during SARS-CoV2 infection, as well as renal function and anti-HLA antibodies in kidney transplant patients 6 months after COVID19 diagnosis. MATERIAL AND METHODS: Retrospective, national multicentre, retrospective study (30 centres) of kidney transplant recipients with COVID19 from 01/02/20 to 31/12/20. Clinical variables were collected from medical records and included in an anonymised database. SPSS statistical software was used for data analysis. RESULTS: renal transplant recipients with COVID19 were included (62.6% male), with a mean age of 57.5 years. The predominant immunosuppressive treatment prior to COVID19 was triple therapy with prednisone, tacrolimus and mycophenolic acid (54.6%) followed by m-TOR inhibitor regimens (18.6%). After diagnosis of infection, mycophenolic acid was discontinued in 73.8% of patients, m-TOR inhibitor in 41.4%, tacrolimus in 10.5% and cyclosporin A in 10%. In turn, 26.9% received dexamethasone and 50.9% were started on or had their baseline prednisone dose increased. Mean creatinine before diagnosis of COVID19, at diagnosis and at 6 months was: 1.7 ±â€¯0.8, 2.1 ±â€¯1.2 and 1.8 ±â€¯1 mg/dl respectively (p < 0.001). 56.9% of the patients (N = 350) were monitored for anti-HLA antibodies. 94% (N = 329) had no anti-HLA changes, while 6% (N = 21) had positive anti-HLA antibodies. Among the patients with donor-specific antibodies post-COVID19 (N = 9), 7 patients (3.1%) had one immunosuppressant discontinued (5 patients had mycophenolic acid and 2 had tacrolimus), 1 patient had both immunosuppressants discontinued (3.4%) and 1 patient had no change in immunosuppression (1.1%), these differences were not significant. CONCLUSIONS: The management of immunosuppressive therapy after diagnosis of COVID19 was primarily based on discontinuation of mycophenolic acid with very discrete reductions or discontinuations of calcineurin inhibitors. This immunosuppression management did not influence renal function or changes in anti-HLA antibodies 6 months after diagnosis.

[Management of immunosuppressive therapy in kidney transplant recipients with COVID19. A multicentre national study derived form the S.E.N. COVID registry.] / Manejo de la inmunosupresión en pacientes trasplantados de riñón con COVID19. Estudio multicéntrico nacional derivado del registro COVID de la S.E.N.

INTRODUCTION: SARS CoV2 infection has had a major impact on renal transplant patients with a high mortality in the first months of the pandemic. Intentional reduction of immunosuppressive therapy has been postulated as one of the cornerstone in the management of the infection in the absence of targeted antiviral treatment. This has been modified according to the patient`s clinical situation and its effect on renal function or anti-HLA antibodies in the medium term has not been evaluated. OBJECTIVES: Evaluate the management of immunosuppressive therapy made during SARS-CoV2 infection, as well as renal function and anti-HLA antibodies in kidney transplant patients 6 months after COVID19 diagnosis. MATERIAL AND METHODS: Retrospective, national multicentre, retrospective study (30 centres) of kidney transplant recipients with COVID19 from 01/02/20 to 31/12/20. Clinical variables were collected from medical records and included in an anonymised database. SPSS statistical software was used for data analysis. RESULTS: 615 renal transplant recipients with COVID19 were included (62.6% male), with a mean age of 57.5 years.The predominant immunosuppressive treatment prior to COVID19 was triple therapy with prednisone, tacrolimus and mycophenolic acid (54.6%) followed by m-TOR inhibitor regimens (18.6%). After diagnosis of infection, mycophenolic acid was discontinued in 73.8% of patients, m-TOR inhibitor in 41.4%, tacrolimus in 10.5% and cyclosporin A in 10%. In turn, 26.9% received dexamethasone and 50.9% were started on or had their baseline prednisone dose increased.Mean creatinine before diagnosis of COVID19, at diagnosis and at 6 months was: 1.7±0.8, 2.1±1.2 and 1.8±1 mg/dl respectively (p<0.001).56.9% of the patients (N=350) were monitored for anti-HLA antibodies. 94% (N=329) had no anti-HLA changes, while 6% (N=21) had positive anti-HLA antibodies. Among the patients with donor-specific antibodies post-COVID19 (N=9), 7 patients (3.1%) had one immunosuppressant discontinued (5 patients had mycophenolic acid and 2 had tacrolimus), 1 patient had both immunosuppressants discontinued (3.4%) and 1 patient had no change in immunosuppression (1.1%), these differences were not significant. CONCLUSIONS: The management of immunosuppressive therapy after diagnosis of COVID19 was primarily based on discontinuation of mycophenolic acid with very discrete reductions or discontinuations of calcineurin inhibitors. This immunosuppression management did not influence renal function or changes in anti-HLA antibodies 6 months after diagnosis.

The Immunobiogram, a Novel In Vitro Assay to Evaluate Treatment Resistance in Patients Receiving Immunosuppressive Therapy.

Immunosuppressive drugs are widely used to treat several autoimmune disorders and prevent rejection after organ transplantation. However, intra-individual variations in the pharmacological response to immunosuppressive therapy critically influence its efficacy, often resulting in poor treatment responses and serious side effects. Effective diagnostic tools that help clinicians to tailor immunosuppressive therapy to the needs and immunological profile of the individual patient thus constitute a major unmet clinical need. In vitro assays that measure immune cell responses to immunosuppressive drugs constitute a promising approach to individualized immunosuppressive therapy. Here, we present the Immunobiogram, a functional pharmacodynamic immune cell-based assay for simultaneous quantitative measurement of a patient's immune response to a battery of immunosuppressive drugs. Peripheral blood mononuclear cells collected from patients are immunologically stimulated to induce activation and proliferation and embedded in a hydrogel mixture in which they are exposed to a concentration gradient of the immunosuppressants of interest. Analysis of samples from kidney transplant patients using this procedure revealed an association between the sensitivity of individual patients to the immunosuppressive regimen and their immunological risk of transplant rejection. Incorporation of the Immunobiogram assay into clinical settings could greatly facilitate personalized optimization and monitoring of immunosuppressive therapy, and study of the mechanisms underlying resistance to immunosuppressants.

Manejo de la inmunosupresión en pacientes trasplantados de riñón con COVID19. Estudio multicéntrico nacional derivado del registro COVID de la Sociedad Española de Nefrología / Management of immunosuppressive therapy in kidney transplant recipients with COVID-19. A multicentre national study derived from the Spanish Society of Nephrology. COVID registry

Introducción: La infección por SARS-CoV2 ha impactado de forma importante en los pacientes con trasplante renal causando una elevada mortalidad en los primeros meses de la pandemia. La reducción intencionada de la inmunosupresión se ha postulado como uno de los pilares en el manejo de la infección ante la falta de un tratamiento antiviral dirigido. Esta se ha modificado de acuerdo con la situación clínica de los pacientes, y su efecto sobre la función renal o los anticuerpos anti-HLA a medio plazo no ha sido evaluado. Objetivos: Evaluar los cambios de inmunosupresión realizados durante la infección por SARS-CoV2, así como la función renal y los anticuerpos anti-HLA de los pacientes trasplantados de riñón a los 6 meses del diagnóstico de COVID19. Material y métodos: Estudio retrospectivo, multicéntrico nacional (30 centros) de pacientes trasplantados de riñón con COVID19 desde el 01/02/20 al 31/12/20. Se recogieron las variables de la historia clínica y se incluyeron en una base de datos anonimizada. Se utilizó el programa estadístico SPSS para el análisis de resultados. (AU)

Introduction: SARS-CoV-2 infection has had a major impact on renal transplant patients with a high mortality in the first months of the pandemic. Intentional reduction of immunosuppressive therapy has been postulated as one of the cornerstone in the management of the infection in the absence of targeted antiviral treatment. This has been modified according to the patient's clinical situation and its effect on renal function or anti-HLA antibodies in the medium term has not been evaluated. Objectives: Evaluate the management of immunosuppressive therapy made during SARS-CoV-2 infection, as well as renal function and anti-HLA antibodies in kidney transplant patients 6 months after COVID-19 diagnosis. Material and methods: Retrospective, national multicentre, retrospective study (30 centres) of kidney transplant recipients with COVID19 from 01/02/20 to 31/12/20. Clinical variables were collected from medical records and included in an anonymised database. SPSS statistical software was used for data analysis. (AU)

[Complications associated with renal graft biopsy in transplant patients]. / Complicaciones asociadas a la biopsia de injertos renales en pacientes trasplantados.

BACKGROUND: Percutaneous biopsy of renal grafts is a diagnostic method for the assessment, management and clinical monitoring of renal transplant, so it is necessary to know its complications. There are few data in the literature regarding complications from biopsies in renal grafts. OBJECTIVE: To evaluate the rate of complications in renal graft biopsies performed at our centre. PATIENTS AND METHOD: We performed a retrospective observational study, including data from patients who underwent renal graft biopsies from January 2000 to September 2012. Major complications were defined as: anemia requiring blood transfusion, intraparenchymal arteriovenous fistula or arterial bleeding requiring embolisation, nephrectomy, other surgery and exitus. And as minor complications: anemia without blood transfusion, intraparenchymal arteriovenous fistula without embolisation, haematomas or perirenal collections, hematuria and fever. Kidney biopsies were performed with ultrasound guidance and automatic devices. RESULTS: We performed 390 kidney graft biopsies. 49 complications occurred. 22 were major: 12 per anemia that required blood transfusion, 6 requiring embolisation (5 arteriovenous fistulae and 1 arterial bleeding), 2 exitus, 1 trasplantectomy and 1 surgery (haematoma). 27 were minor: 12 perirenal collections, 9 arteriovenous fistulae without embolisation, 3 hematuria, 2 anemisation without blood transfusion and 1 fever. CONCLUSIONS: The rate of complications related to renal graft biopsy observed in our centre is similar to those described for native kidneys, therefore we believe it remains a safe and effective technique, and an important diagnostic tool.

Pretransplant peritoneal dialysis relative to hemodialysis improves long-term survival of kidney transplant patients: a single-center observational study.

BACKGROUND: Kidney transplantation is the best option for the treatment of end-stage renal disease in terms of survival and quality of life. These results can be influenced by the pretransplant dialysis modality. The aim of this study was to evaluate whether the pretransplantation dialysis modality influences patient and allograft survival beyond 10 years and examine the potential risk factors associated with the outcomes. METHODS: We conducted an observational, retrospective, single-center clinical study that included 236 patients [118 undergoing peritoneal dialysis (PD) and 118 undergoing hemodialysis (HD)] who proceeded to transplantation during the period December 1990-2002. Donor and recipient data were collected from our hospital's clinical registries. The follow-up period extended to the patient's death, the loss of the allograft, or loss to follow-up. The end date of the study was set at March 2012. RESULTS: In the multivariate analysis, the long-term patient survival rate was higher for the PD group than for the HD group [HR = 2.62 (1.01-6.8); p = 0.04]; however, the allograft survival rate was not significantly different between the two groups [HR = 0.68 (0.41-1.10); p = 0.12]. CONCLUSION: Pretransplantation dialysis modality is associated with long-term patient survival, with outcomes favoring peritoneal dialysis over hemodialysis. However, the pretransplant dialysis modality does not influence long-term graft loss risk.

Switch to belatacept in kidney graft recipients / Cambio a belatacept en trasplante renal

No disponible

Complicaciones asociadas a la biopsia de injertos renales en pacientes trasplantados / Complications Associated with Renal Graft Biopsy in Transplant Patients

Antecedentes: La biopsia percutánea de injertos renales es un método diagnóstico para la evaluación, manejo y seguimiento clínico del trasplante renal, por lo cual es necesario conocer sus complicaciones. Existen pocos datos en la literatura en relación con las complicaciones derivadas de las biopsias en injertos renales. Objetivo: Evaluar la tasa de complicaciones de las biopsias realizadas en injertos renales en nuestro centro. Pacientes y métodos: Estudio observacional retrospectivo. Se incluyeron las biopsias de injertos renales realizadas entre enero de 2000 y septiembre de 2012. Se definieron como complicaciones mayores: anemización que requirió transfusión sanguínea, fístula arteriovenosa intraparenquimatosa o sangrado arterial que requirieron embolización, trasplantectomía, otro tipo de cirugía y exitus. Y como complicaciones menores: anemización sin transfusión sanguínea, fístula arteriovenosa intraparenquimatosa sin embolización, hematomas o colecciones perirrenales, hematuria y fiebre. Las biopsias renales fueron realizadas bajo control ecográfico y con dispositivos automáticos. Resultados: Se realizaron 390 biopsias a injertos renales. Se produjeron 49 complicaciones. Veintidós fueron mayores: 12 por anemización que precisaron transfusión sanguínea, 6 requirieron embolización (5 por fístulas arteriovenosas y 1 por sangrado arterial), 2 exitus, 1 trasplantectomía y 1 intervención quirúrgica (por hematoma). Veintisiete fueron menores: 12 colecciones perirrenales, 9 fístulas arteriovenosas sin embolización, 3 hematurias, 2 anemizaciones sin transfusión sanguínea y 1 fiebre. Conclusión: La tasa de complicaciones relacionadas con la biopsia del injerto renal observada en nuestro centro es similar a las descritas sobre riñones nativos; por lo tanto, consideramos que es también una técnica segura y eficaz, y una importante herramienta diagnóstica (AU)

Background: Percutaneous biopsy of renal grafts is a diagnostic method for the assessment, management and clinical monitoring of renal transplant, so it is necessary to know its complications. There are few data in the literature regarding complications from biopsies in renal grafts. Objective: To evaluate the rate of complications in renal graft biopsies performed at our centre. Patients and Method: We performed a retrospective observational study, including data from patients who underwent renal graft biopsies from January 2000 to September 2012. Major complications were defined as: anemia requiring blood transfusion, intraparenchymal arteriovenous fistula or arterial bleeding requiring embolisation, nephrectomy, other surgery and exitus. And as minor complications: anemia without blood transfusion, intraparenchymal arteriovenous fistula without embolisation, haematomas or perirenal collections, hematuria and fever. Kidney biopsies were performed with ultrasound guidance and automatic devices. Results: We performed 390 kidney graft biopsies. 49 complications occurred. 22 were major: 12 per anemia that required blood transfusion, 6 requiring embolisation (5 arteriovenous fistulae and 1 arterial bleeding), 2 exitus, 1 trasplantectomy and 1 surgery (haematoma). 27 were minor: 12 perirenal collections, 9 arteriovenous fistulae without embolisation, 3 hematuria, 2 anemisation without blood transfusion and 1 fever. Conclusions: The rate of complications related to renal graft biopsy observed in our centre is similar to those described for native kidneys, therefore we believe it remains a safe and effective technique, and an important diagnostic tool (AU)