Low-risk delisting strategy in highly sensitized patients without donor offers included in exchange donation programs. One single-center experience.

Donor exchange programs were designed to allocate organs for highly sensitized (HS) patients. The allocation algorithm differs slightly among countries and includes different strategies to improve access to transplants in HS patients. However, many HS patients with a calculated panel reactive of antibodies (cPRA) of 100 % remain on the waiting list for a long time. Some allocation algorithms assume immunological risk, including Imlifidase treatment, to increase the chance of transplantation in very HS patients. Here, we describe our unicenter experience of low-risk delisting strategy in 15 HS patients included in the Spanish donor exchange program without donor offers. After delisting, 7 out of 15 HS patients reduced the cPRA below 99.95 % and impacted the reduction of time on the waiting list (p = 0.01), where 5 out of 7 achieved transplantation. Within those HS that remained above 99.95 %, 1 out of 8 was transplanted. All the HS were transplanted with delisted DSA, and only one with DSA level rebounded early after transplantation. All HS transplanted after delisting maintain graft function. The transplant immunology laboratories are challenged to search intermediate risk assessment methods for delisting high HS patients.

Looking into the Eyes to See the Heart of Chronic Kidney Disease Patients.

In patients with chronic kidney disease (CKD), the main cause of morbidity and mortality is cardiovascular disease (CVD). Both coronary artery calcium scoring by computed tomography (CT) and optical coherence tomography (OCT) are used to identify patients at increased risk for ischemic heart disease, thereby indicating a higher cardiovascular risk profile. Our study aimed to investigate the utility of these techniques in the CKD population. In patients with CKD, OCT was used to measure the choroidal thickness (CHT) and the thickness of the peripapillary retinal nerve fiber layer (pRNFL). A total of 127 patients were included, including 70 men (55%) with an estimated glomerular filtration rate (eGFR) of 39 ± 30 mL/min/1.73 m2. Lower pRNFL thickness was found to be related to high-sensitivity troponin I (r = -0.362, p < 0.001) and total coronary calcification (r = -0.194, p = 0.032). In a multivariate analysis, pRNFL measurements remained associated with age (ß = -0.189; -0.739--0.027; p = 0.035) and high-sensitivity troponin I (ß = -0.301; -0.259--0.071; p < 0.001). Severe coronary calcification (Agatston score ≥ 400 HU) was related to a worse eGFR (p = 0.008), a higher grade of CKD (p = 0.036), and a thinner pRNFL (p = 0.011). The ROC curve confirmed that the pRNFL measurement could determine the patients with an Agatston score of ≥400 HU (AUC 0.638; 95% CI 0.525-0.750; p = 0.015). Our study concludes that measurement of pRNFL thickness using OCT is related to the markers associated with ischemic heart disease, such as coronary calcification and high-sensitivity troponin I, in the CKD population.

Donor-Derived Cell-Free DNA at 1 Month after Kidney Transplantation Relates to HLA Class II Eplet Mismatch Load.

Kidney transplantation is the preferred therapeutic option for end-stage renal disease; however, the alloimmune response is still the leading cause of renal allograft failure. To better identify immunologic disparities in order to evaluate HLA compatibility between the donor and the recipient, the concept of eplet load has arisen. Regular kidney function monitoring is essential for the accurate and timely diagnosis of allograft rejection and the appropriate treatment. Donor-derived cell-free DNA (dd-cfDNA) has been proposed as a potential biomarker of acute rejection and graft failure in kidney transplantation. The proportion of plasma dd-cfDNA was determined in forty-two kidney patients at 1 month after transplantation. A total of eleven (26.2%) patients had a dd-cfDNA proportion of ≥1.0%. The only pretransplant variable related to dd-cfDNA > 1.0% was the HLA class II eplet mismatch load, mainly the HLA-DQB1 eplet mismatch load. Furthermore, dd-cfDNA was able to discriminate the patients with antibody-mediated rejection (AbMR) (AUC 87.3%), acute rejection (AUC 78.2%), and troubled graft (AUC 81.4%). Increased dd-cfDNA levels were associated with kidney allograft deterioration, particularly rejection, as well as a greater HLA class II eplet mismatch load. Consequently, combining dd-cfDNA determination and HLA eplet mismatch load calculation should improve the assessment of the risk of short- and long-term allograft damage.

Association of severe preeclampsia and vascular damage assessed by noninvasive markers of arterial stiffness.

BACKGROUND: Preeclampsia (PE) is a hypertensive disorder of pregnancy associated with high maternal and fetal morbidity and mortality and increased future risk of cardiovascular complications. OBJECTIVE: To analyze whether women who have had PE with severe features in their pregnancy have higher arterial stiffness (AS) parameters than those whose PE course was without signs of severity. METHODS: Sixty-five women who developed PE during their gestation were evaluated, divided into two groups: PE group without severe features or non-severe PE (n=30) and PE group with severe features or severe PE (n=35). Carotid-femoral pulse wave velocity (cfPWV), central augmentation index corrected to a heart rate of 75 beats per minute (AIxc75) and central augmentation pressure (cAP) were determined one month and six months postpartum. Comparison of proportions was carried out using the chi-square test, comparison of means between groups using the Student's t-test or the Mann-Whitney test, and comparison of means of the same group at different evolutionary moments, using the t-test or the Wilcoxon test. Correlation, with and between hemodynamic parameters, was carried out with Spearman's correlation coefficient and the association between demographic variables, personal history and hemodynamic parameters, and altered arterial stiffness parameters was carried out using linear and logistic regression models. RESULTS: Women with severe PE presented, both at 1 and 6 months postpartum, higher values of blood pressure, both central and peripheral, as well as AR and pulse amplification parameters, than those women whose PE was not severe. Central augmentation index (cAIx) values at 1 month and 6 months postpartum were higher, although not significantly, in the severe PE group compared to the non-severe PE group (24.0 (16.5-34.3) vs. 19.0% (14-29) and 24.0 (14.0-30.0) vs. 20.0% (12.3-26.8), respectively). Carotid-femoral pulse wave velocity (cfPWV) was significantly higher at both 1 and 6 months postpartum in the severe PE group compared to the non-severe PE group (10.2 (8.8-10.7) vs. 8.8m/s (8.3-9.6) and 10.0 (8.8-10.6) vs. 8.8m/s (8.3-9.3), respectively). Central systolic pressure and central pulse pressure amplification were also higher, although not significantly, in the severe PE group in comparison with the non-severe PE group. CONCLUSIONS: Women who have had severe PE have more pronounced arterial stiffness parameters than those in whom PE was not particularly severe. The determination of cAIx and cfPWV, as a strategy for the assessment of cardiovascular risk, should be evaluated among women who have had PE.

Non-HLA Antibodies and Their Role in Highly Sensitized Patients.

BACKGROUND: The role of non-HLA antibody is gaining special attention in solid-organ transplantation and in highly sensitized (HS) patients because of its potential involvement in graft loss (GL) and/or antibody-mediated rejection (ABMR). The identification of non-HLA antibodies while listed may provide deeper information about the increased immunologic risk prior to transplant. We aimed to identify non-HLA antibodies pretransplant that could involve GL in HS patients. METHODS: Nineteen pretransplant samples from HS patients who underwent transplant at the Marqués de Valdecilla University Hospital were studied for both HLA antibodies and a panel of 39 non-HLA antigens analyzed based on Luminex platform. RESULTS: Eleven patient (57.9%) maintained the graft (KT group), whereas 8 (42.1%) had a GL within a median of 30 days. The median fluorescent intensity (MFI) of the 39 non-HLA antigens were compared within the groups, obtaining a statistically significant differences in protein tyrosine phosphatase receptor type N (P < .04) with a MFI mean of 1408 vs 4931 for KT and GL groups, respectively. However, no significant differences were observed in non-HLA MFI between ABMR and non-ABMR KT recipients. CONCLUSIONS: The presence of non-HLA antibodies in HS is high. The levels of anti-protein tyrosine phosphatase receptor type N before transplant could indicate a potential risk of GL, although longitudinal studies with large number of cases are needed to define anti-non-HLA profiles of risk of ABMR.

Increased induction of de novo serum ANCA and ANCA-associated vasculitis after mass vaccination against SARS-CoV-2.

Different immune-mediated diseases have been described after SARS-CoV-2 vaccination, with antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) being one of the possible side effects. In this study, a total of 35 patients presented ANCA for the first time during 2021, with the number during 2019 being 15. Twenty-seven out of thirty-five patients developed ANCA after vaccination. Two of them developed these antibodies after receiving the first dose (7.4%), and 25 patients developed ANCA after the second dose of the vaccine (92.6%), with BNT162b2 being the main vaccine received by these patients. In 97.1% of the patients who developed ANCA during 2021, the positivity of ANCA was accompanied by systemic involvement, with renal and respiratory tracts being the main organs affected. Therefore, an increase in the development of AAV has been observed during 2021 in comparison with 2019, which could be due to the administration of SARS-CoV-2 vaccine.

The ERA Registry Annual Report 2019: summary and age comparisons.

BACKGROUND: Data on renal replacement therapy (RRT) for end-stage renal disease were collected by the European Renal Association (ERA) Registry via national and regional renal registries in Europe and countries bordering the Mediterranean Sea. This article provides a summary of the 2019 ERA Registry Annual Report, including data from 34 countries and additional age comparisons. METHODS: Individual patient data for 2019 were provided by 35 registries and aggregated data by 17 registries. Using these data, the incidence and prevalence of RRT, the kidney transplantation activity and the survival probabilities were calculated. RESULTS: In 2019, a general population of 680.8 million people was covered by the ERA Registry. Overall, the incidence of RRT was 132 per million population (p.m.p.). Of these patients, 62% were men, 54% were ≥65 years of age and 21% had diabetes mellitus as primary renal disease (PRD), and 84% had haemodialysis (HD), 11% had peritoneal dialysis (PD) and 5% had pre-emptive kidney transplantation as an initial treatment modality. The overall prevalence of RRT on 31 December 2019 was 893 p.m.p., with 58% of patients on HD, 5% on PD and 37% living with a kidney transplant. The overall kidney transplant rate was 35 p.m.p. and 29% of the kidney grafts were from a living donor. The unadjusted 5-year survival probability was 42.3% for patients commencing dialysis, 86.6% for recipients of deceased donor grafts and 94.4% for recipients of living donor grafts in the period 2010-14. When comparing age categories, there were substantial differences in the distribution of PRD, treatment modality and kidney donor type, and in the survival probabilities.

Growth Differentiation Factor 15 Is Superior to Troponin I in the Evaluation of Kidney Transplant Candidates.

INTRODUCTION: Pretransplant cardiac troponin I (cTNI) has demonstrated its predicting value in survival after kidney transplant. Growth differentiation factor 15 (GDF-15) is a biomarker currently studied as a predictor of mortality and cardiovascular events (CVE) in different scenarios. The aim of this study was to compare the utility of these two biomarkers in the prediction of events after kidney transplant. METHODS: We included 359 kidney transplants performed in our center between 2005 and 2015. cTNI and GDF-15 were measured on stored serum samples obtained pretransplant. RESULTS: Median GDF-15 was 5,346.4 pg/mL, and cTNI was 5.6 ng/L. After follow-up, 77 (21.5%) patients died, and the incidence of cerebrovascular accident (CVA), acute coronary syndrome (ACS), and major adverse CVEs (MACE) was 6.38%, 12.68%, and 20.56%, respectively. Patients were stratified in tertiles according to GDF-15 and cTNT levels. By multivariate cox regression analysis including both biomarkers and different clinical characteristics, we found a significant relation between GDF-15 and mortality, CVAs, and MACE (highest tertile hazard ratio [HR] 2.2 95% confidence interval [CI] [1.2-4.1], p = 0.01, HR 9.7 CI 95% [2.2-43.1], p = 0.003 and HR 2.7 CI 95% [1.4-5.1], p = 0.002). On the contrary, posttransplant ACS was related to cTNI (highest cTNI tertile HR 3.2 CI 95% [1.5-7.3], p = 0.003). DISCUSSION: Our study indicates the potential utility of GDF-15 as a mortality and CVE predictor after kidney transplant and its superiority compared to cTNI. By contrast, probably due to its tissue specificity, cardiac troponin showed a stronger correlation with acute coronary events. Although more studies are needed to confirm our findings, these two molecules could be used in conjunction with other tools to predict adverse events after transplant and ideally find strategies to minimize them.

Long-term survival of renal transplantation in patients with lupus nephritis: experience from a single university centre.

OBJECTIVES: Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE). Unfortunately, 10-20% of patients with LN develop end-stage renal disease (ESRD), and renal transplantation may be a therapeutic option. However, concerns about LN recurrence after transplant have been reported. We aimed to assess long-term post-transplant graft and patient survival in LN compared to patients with non-autoimmune nephropathy (polycystic kidney disease - PCKD). METHODS: We carried out a single-centre retrospective study of all patients who underwent renal transplantation due to LN in a referral unit between 1980 and 2018. This cohort was compared with a group of PCKD patients. The main outcome variables were graft and patient survival for up to 20 years, and the time-course of serum creatinine and proteinuria in the first 5 years after transplantation. Cumulative survival rates were estimated by the Kaplan-Meier method and compared using the log-rank test. RESULTS: We included 53 patients: LN group (n=21) and PCKD group (n=32). Baseline clinical characteristics were similar in both groups, except age at transplantation (39.8±11.3 years in the LN group and 46.6±5.0 years in the PCKD group; p=0.004). No significant differences were found regarding graft (p=0.59) or patient survival (p=0.087) at 20 years of follow-up. CONCLUSIONS: Despite concerns about LN recurrence after renal transplantation, this study shows that this procedure might be a safe alternative therapy for ESRD related to SLE and may provide long-term survival.

Safety and immediate humoral response of COVID-19 vaccines in chronic kidney disease patients: the SENCOVAC study.

BACKGROUND: Chronic kidney disease (CKD) patients are at high-risk for severe coronavirus disease 2019 (COVID-19). The multicentric, observational and prospective SENCOVAC study aims to describe the humoral response and safety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in CKD patients. Safety and immediate humoral response results are reported here. METHODS: Four cohorts of patients were included: kidney transplant (KT) recipients, and haemodialysis (HD), peritoneal dialysis (PD) and non-dialysis CKD patients from 50 Spanish centres. Adverse events after vaccine doses were recorded. At baseline and on Day 28 after the last vaccine dose, anti-Spike antibodies were measured and compared between cohorts. Factors associated with development of anti-Spike antibodies were analysed. RESULTS: A total of 1746 participants were recruited: 1116 HD, 171 PD, 176 non-dialysis CKD patients and 283 KT recipients. Most patients (98%) received mRNA vaccines. At least one vaccine reaction developed after the first dose in 763 (53.5%) and after the second dose in 741 (54.5%) of patients. Anti-Spike antibodies were measured in the first 301 patients. At 28 days, 95% of patients had developed antibodies: 79% of KT, 98% of HD, 99% of PD and 100% of non-dialysis CKD patients (P < 0.001). In a multivariate adjusted analysis, absence of an antibody response was independently associated with KT (odds ratio 20.56, P = 0.001) and with BNT162b2 vaccine (odds ratio 6.03, P = 0.023). CONCLUSION: The rate of anti-Spike antibody development after vaccination in KT patients was low but in other CKD patients it approached 100%, suggesting that KT patients require persistent isolation measures and booster doses of a COVID-19 vaccine. Potential differences between COVID-19 vaccines should be explored in prospective controlled studies.

Oral decontamination with colistin plus neomycin in solid organ transplant recipients colonized by multidrug-resistant Enterobacterales: a multicentre, randomized, controlled, open-label, parallel-group clinical trial.

OBJECTIVES: To evaluate the efficacy of oral colistin-neomycin in preventing multidrug-resistant Enterobacterales (MDR-E) infections in solid organ transplant (SOT) recipients. METHODS: Multicentre, open-label, parallel-group, controlled trial with balanced (1:1) randomization in five transplant units. SOT recipients were screened for MDR-E intestinal colonization (extended-spectrum ß-lactamase or carbapenemase producing) before transplantation and +7 and + 14 days after transplantation and assigned 1:1 to receive treatment with colistin sulfate plus neomycin sulfate for 14 days (decolonization treatment (DT) group) or no treatment (no decolonization treatment (NDT) group). The primary outcome was diagnosis of an MDR-E infection. Safety outcomes were appearance of adverse effects, mainly diarrhoea, rash, nausea and vomiting. Patients were monitored weekly until 30 days after treatment. Intention-to-treat analysis was performed. RESULTS: MDR-E rectal colonization was assessed in 768 SOT recipients; 105 colonized patients were included in the clinical trial, 53 receiving DT and 52 NDT. No significant decrease in the risk of infection by MDR-E was observed in the DT group (9.4%, 5/53) compared to the NDT group (13.5%, 7/52) (relative risk 0.70; 95% confidence interval 0.24-2.08; p 0.517). Four patients (5.6%), three (5.6%) in the DT group and one (1.9%) in the NDT group, developed colistin resistance. Twelve patients (22.7%) in the DT group had diarrhoea, eight related to treatment (15.0%); one patient (1.8%) developed skin rash and another (1.8%) nausea and vomiting. Two patients (3.8%) in the NDT group developed diarrhoea. CONCLUSIONS: DT does not reduce MDR-E infections in SOT. Colistin resistance and adverse effects such as diarrhoea are a potential issue that must be taken seriously.

Advanced Chronic Kidney Disease Units in Spain: a national survey on standards of structure, resources, results and patient safety. / Unidades de Enfermedad Renal Crónica Avanzada en España: una encuesta nacional sobre los estándares de estructura, recursos, resultados y seguridad del paciente.

BACKGROUND AND OBJECTIVE: Recently, the Advanced Chronic Kidney Disease Units (UERCA, in Spanish) have been developed in Spain to offer a better quality of life to patients with advanced chronic kidney disease (ACKD), improving their survival and reducing morbidity in this phase of the disease. Nowadays, there is not much evidence in the Spanish and international literature regarding the structure and how to achieve these objectives in the UERCA. From the ERCA working group of the Spanish Society of Nephrology (SEN), this project is promoted to improve care for ERCA patients through the definition of quality standards for the operation of the UERCA. MATERIAL AND METHODS: An initial proposal for quality standards concerning the operation of the UERCA was configured through consultation with the main sources of references and the advice of an expert working group through face-to-face and telematic meetings. Base on this initial proposal of standards, a survey was conducted and sent it via email to 121 nephrology specialist and nursing professionals with experience in Spanish UERCA to find out, among others, the suitability of each standards, that is, its mandatory nature or recommendation as standards. The access to the survey was allowed between July 16th, 2018, until September 26th, 2018. RESULTS: A total of 95 (78.5%) professionals participated out of the 121 who were invited to participate. Of these, 80 of the participants were nephrology specialists and 15 nursing professionals, obtaining a varied representation of professionals from the Spanish geography. After analyzing the opinions of these participants, the standards were defined to a total of 68, 37 of them (54.4%) mandatory and 31 of them (45.5%) recommended. Besides, it was observed that the volume of patients attended in the UERCA is usually above 100 patients, and the referral criteria is generally below 25-29 mL/min/1.73 m2 of glomerular filtration. CONCLUSIONS: This work constitutes a first proposal of quality standards for the operation of UERCA in Spain. The definition of these standards has made it possible to establish the bases for the standardization of the organization of UERCA, and to subsequently work on the configuration of a standards manual for the accreditation of ERCA Units.

Strict selection criteria in uncontrolled donation after circulatory death provide excellent long-term kidney graft survival.

BACKGROUND: We aimed to report our experience in uncontrolled donation after circulatory death (uDCD) kidney transplantation applying a strict donor selection and preservation criteria. METHODS: All kidney recipients received a graft from a local uDCD. As controls, we included all renal transplants from local standard criteria donation after brain death (SDBD) donors. Normothermic regional perfusion was the preservation method in all cases. RESULTS: A total of 19 kidneys from uDCD donors were included and 67 controls. Delayed graft function (DGF) was higher in the uDCD group (42.1% vs 17.9%; P = .033), whereas no differences were observed in primary nonfunction (0% cases vs 3% controls; P = .605). The estimated glomerular filtration rate was identical in both groups. No differences were observed in graft survival censored for death between the uDCD and the SDBD groups at 1-year (100% vs 95%) or 5-year follow-up (92% vs 91%). uDCD kidney recipients did not have higher risk of graft loss in the multivariate analysis adjusted by recipient age, cold ischemic time, presence of DGF, and second kidney transplant (HR: 0.4; 95% CI 0.02-6; P = .509). CONCLUSIONS: Obtaining renal grafts from uDCD is feasible in a small city and provides similar outcomes compared to standard DBD donors.

Immunosuppression with Calcineurin Inhibitor after Renal Transplant Failure Inhibits Allosensitization.

Immunosuppression withdrawal after graft failure seems to favor sensitization. A high percentage of calculated panel-reactive antibody (cPRA) and the development of de novo donor specific antibodies (dnDSA) indicate human leukocyte antigen (HLA) sensitization and may hinder the option of retransplantation. There are no established protocols on the immunosuppressive treatment that should be maintained after transplant failure. A retrospective analysis including 77 patients who lost their first renal graft between 1 January 2006-31 December 2015 was performed. Two sera were selected per patient, one immediately prior to graft loss and another one after graft failure. cPRA was calculated by Single Antigen in all patients. It was possible to analyze the development of dnDSA in 73 patients. By multivariate logistic regression analysis, the absence of calcineurin inhibitor (CNI) at 6 months after graft failure was related to cPRA > 75% (OR 4.8, CI 95% 1.5-15.0, p = 0.006). The absence of calcineurin inhibitor (CNI) at 6 months after graft loss was significantly associated with dnDSA development (OR 23.2, CI 95% 5.3-100.6, p < 0.001). Our results suggest that the absence of CNI at the sixth month after graft loss is a risk factor for sensitization. Therefore, maintenance of an immunosuppressive regimen based on CNI after transplant failure should be considered when a new transplant is planned, since it seems to prevent HLA allosensitization.

High Pretransplant BAFF Levels and B-cell Subset Polarized towards a Memory Phenotype as Predictive Biomarkers for Antibody-Mediated Rejection.

Antibody-mediated rejection (AbMR) is one of the leading causes of graft loss in kidney transplantation and B cells play an important role in the development of it. A B-cell activating factor (BAFF) is a cytokine involved in B cell ontogeny. Here, we analyzed whether B cell maturation and the effect of B cell soluble factors, such as BAFF could be involved in AbMR. Serum BAFF levels and B and T cell subpopulations were analyzed 109 kidney transplant patients before transplantation and at 6 and 12 months after kidney transplantation. Pretransplant serum BAFF levels as well as memory B cell subpopulations were significantly higher in those patients who suffered clinical AbMR during the first 12 months after kidney transplantation. Similar results were observed in the prospective analysis of patients with subclinical antibody-mediated rejection detected in the surveillance biopsy performed at 12 months after kidney transplantation. A multivariate analysis confirmed the independent role of BAFF in the development of AbMR, irrespective of other classical variables. Pretransplant serum BAFF levels could be an important non-invasive biomarker for the prediction of the development of AbMR and posttransplant increased serum BAFF levels contribute to AbMR.

Growth Differentiation Factor 15: A Biomarker with High Clinical Potential in the Evaluation of Kidney Transplant Candidates.

Kidney transplantation implies a significant improvement in patient survival. Nevertheless, early mortality after transplant remains high. Growth differentiation factor 15 (GDF-15) is a novel biomarker under study as a mortality predictor in multiple scenarios. The aim of this study is to assess the utility of GDF-15 to predict survival in kidney transplant candidates. For this purpose, 395 kidney transplant recipients with pretransplant stored serum samples were included. The median GDF-15 was 5331.3 (50.49-16242.3) pg/mL. After a mean of 90.6 ± 41.5 months of follow-up, 82 (20.8%) patients died. Patients with higher GDF-15 levels (high risk tertile) had a doubled risk of mortality after adjustment by clinical characteristics (p = 0.009). After adjustment by EPTS (Estimated Post Transplant Survival score) the association remained significant for medium hazards ratios (HR) 3.24 95%CI (1.2-8.8), p = 0.021 and high risk tertiles HR 4.3 95%CI (1.65-11.54), p = 0.003. GDF-15 improved the prognostic accuracy of EPTS at 1-year (ΔAUC = 0.09, p = 0.039) and 3-year mortality (ΔAUC = 0.11, p = 0.036). Our study suggests an independent association between higher GDF-15 levels and mortality after kidney transplant, adding accuracy to the EPTS score, an established risk prediction model currently used in kidney transplant candidates.