High-dimensional mass cytometry identified circulating natural killer T-cell subsets associated with protection from cytomegalovirus infection in kidney transplant recipients.

Cytomegalovirus (CMV) infection is associated with poor kidney transplant outcomes. While innate and adaptive immune cells have been implicated in its prevention, an in-depth characterization of the in vivo kinetics of multiple cell subsets and their role in protecting against CMV infection has not been achieved. Here, we performed high-dimensional immune phenotyping by mass cytometry, and functional assays, on 112 serially collected samples from CMV seropositive kidney transplant recipients. Advanced unsupervised deep learning analysis was used to assess immune cell populations that significantly correlated with prevention against CMV infection and anti-viral immune function. Prior to infection, kidney transplant recipients who developed CMV infection showed significantly lower CMV-specific cell-mediated immune (CMI) frequencies than those that did not. A broad diversity of circulating cell subsets within innate and adaptive immune compartments were associated with CMV infection or protective CMV-specific CMI. While percentages of CMV (tetramer-stained)-specific T cells associated with high CMI responses and clinical protection, circulating CD3+CD8midCD56+ NK-T cells overall strongly associated with low CMI and subsequent infection. However, three NK-T cell subsets sharing the CD11b surface marker associated with CMV protection and correlated with strong anti-viral CMI frequencies in vitro. These data were validated in two external independent cohorts of kidney transplant recipients. Thus, we newly describe the kinetics of a novel NK-T cell subset that may have a protective role in post-transplantation CMV infection. Our findings pave the way to more mechanistic studies aimed at understanding the function of these cells in protection against CMV infection.

Benefits of Living Over Deceased Donor Kidney Transplantation in Elderly Recipients. A Propensity Score Matched Analysis of a Large European Registry Cohort.

Although kidney transplantation from living donors (LD) offers better long-term results than from deceased donors (DD), elderly recipients are less likely to receive LD transplants than younger ones. We analyzed renal transplant outcomes from LD versus DD in elderly recipients with a propensity-matched score. This retrospective, observational study included the first single kidney transplants in recipients aged ≥65 years from two European registry cohorts (2013-2020, n = 4,257). Recipients of LD (n = 408), brain death donors (BDD, n = 3,072), and controlled cardiocirculatory death donors (cDCD, n = 777) were matched for donor and recipient age, sex, dialysis time and recipient diabetes. Major graft and patient outcomes were investigated. Unmatched analyses showed that LD recipients were more likely to be transplanted preemptively and had shorter dialysis times than any DD type. The propensity score matched Cox's regression analysis between LD and BDD (387-pairs) and LD and cDCD (259-pairs) revealing a higher hazard ratio for graft failure with BDD (2.19 [95% CI: 1.16-4.15], p = 0.016) and cDCD (3.38 [95% CI: 1.79-6.39], p < 0.001). One-year eGFR was higher in LD transplants than in BDD and cDCD recipients. In elderly recipients, LD transplantation offers superior graft survival and renal function compared to BDD or cDCD. This strategy should be further promoted to improve transplant outcomes.

Mortality in elderly patients starting hemodialysis program.

BACKGROUND: The incidence of older patients over 80 years old with chronic kidney disease who start hemodialysis (HD) program has been increasing in the last decade. METHODS: We aimed to identify risk factors for morbidity and mortality in patients older than 80 years with end-stage renal disease who started HD. We conducted a retrospective observational study of the Catalan Renal registry (RMRC). RESULTS: A total of 2833 patients equal or older than 80 years (of 15,137) who started HD between 2002 and 2019 from the RMRC were included in the study. In this group, the first dialysis was performed through an arteriovenous fistula in 44%, percutaneous catheter in 28.2%, and tunneled catheter in 26.6%. Conventional dialysis was used in 65.7% and online HD in 34.3%. The most frequent cause of death was cardiac disease (21.8%), followed by social problems (20.4%) and infections (15.9%). Overall survival in older HD during the first year was 84% versus 91% in younger than 80 years (p < 0.001). Cox regression analysis identified the start of HD in the period 2002-2010, chronic obstructive pulmonary disease (COPD), and the onset of HD through vascular graft depicted as risk factors for first-year mortality after dialysis initiation in patients older than 80 years with end-stage renal disease who started HD. CONCLUSIONS: In conclusion, patients older than 80 years who started HD program had higher mortality, especially those who presented exacerbation of kidney disease, those with COPD, and those who started with a vascular graft.

A comprehensive assessment of long-term SARS-CoV-2-specific adaptive immune memory in convalescent COVID-19 Solid Organ Transplant recipients.

Long-term adaptive immune memory has been reported among immunocompetent individuals up to eight months following SARS-CoV-2 infection. However, limited data is available in convalescent patients with a solid organ transplant. To investigate this, we performed a thorough evaluation of adaptive immune memory at different compartments (serological, memory B cells and cytokine [IFN-γ, IL-2, IFN-γ/IL12 and IL-21] producing T cells) specific to SARS-CoV-2 by ELISA and FluoroSpot-based assays in 102 convalescent patients (53 with a solid organ transplants (38 kidney, 5 liver, 5 lung and 5 heart transplant) and 49 immunocompetent controls) with different clinical COVID-19 severity (severe, mild and asymptomatic) beyond six months after infection. While similar detectable memory responses at different immune compartments were detected between those with a solid organ transplant and immunocompetent individuals, these responses were predominantly driven by distinct COVID-19 clinical severities (97.6%, 80.5% and 42.1%, all significantly different, were seropositive; 84% vs 75% vs 35.7%, all significantly different, showed IgG-producing memory B cells and 82.5%, 86.9% and 31.6%, displayed IFN-γ producing T cells; in severe, mild and asymptomatic convalescent patients, respectively). Notably, patients with a solid organ transplant with longer time after transplantation did more likely show detectable long-lasting immune memory, regardless of COVID-19 severity. Thus, our study shows that patients with a solid organ transplant are capable of maintaining long-lasting peripheral immune memory after COVID-19 infection; mainly determined by the degree of infection severity.

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.

Corrigendum: Enteric Budesonide in Transplant and Native IgA Nephropathy: Real-World Clinical Practice.

[This corrects the article DOI: 10.3389/ti.2022.10693.].

Deciphering transplant outcomes of expanded kidney allografts donated after controlled circulatory death in the current transplant era. A call for caution.

Outcomes of kidney transplantation (KT) after controlled circulatory death (cDCD) with highly expanded criteria donors (ECD) and recipients have not been thoroughly evaluated. We analyzed in a multicenter cohort of 1161 consecutive KT, granular baseline donor and recipient factors predicting transplant outcomes, selected by bootstrapping and Cox proportional hazards, and were validated in a contemporaneous European KT cohort (n = 1585). 74.3% were DBD and 25.7% cDCD-KT. ECD-KT showed the poorest graft survival rates, irrespective of cDCD or DBD (log-rank < 0.001). Besides standard ECD classification, dialysis vintage, older age, and previous cardiovascular recipient events together with low class-II-HLA match, long cold ischemia time and combining a diabetic donor with a cDCD predicted graft loss (C-Index 0.715, 95% CI 0.675-0.755). External validation showed good prediction accuracy (C-Index 0.697, 95%CI 0.643-0.741). Recipient older age, male gender, dialysis vintage, previous cardiovascular events, and receiving a cDCD independently predicted patient death. Benefit/risk assessment of undergoing KT was compared with concurrent waitlisted candidates, and despite the fact that undergoing KT outperformed remaining waitlisted, remarkably high mortality rates were predicted if KT was undertaken under the worst risk-prediction model. Strategies to increase the donor pool, including cDCD transplants with highly expanded donor and recipient candidates, should be performed with caution.

COVID-19 in CKD Patients: Lessons from 553 CKD Patients with Biopsy-Proven Kidney Disease.

INTRODUCTION: Chronic kidney disease (CKD) patients infected with COVID-19 are at risk of serious complications such as hospitalization and death. The prognosis and lethality of COVID-19 infection in patients with established kidney disease has not been widely studied. METHODS: Data included patients who underwent kidney biopsy at the Vall d'Hebron Hospital between January 2013 and February 2020 with COVID-19 diagnosis during the period from March 1 to May 15, 2020. RESULTS: Thirty-nine (7%) patients were diagnosed with COVID-19 infection. Mean age was 63 ± 15 years and 48.7% were male. Hypertension was present in 79.5%, CKD without renal replacement therapy in 76.9%, and cardiovascular disease in 64.1%. Nasopharyngeal swab was performed in 26 patients; older (p = 0.01), hypertensive (p = 0.005), and immunosuppressed (p = 0.01) patients, those using RAS-blocking drugs (p = 0.04), and those with gastrointestinal symptoms (p = 0.02) were more likely to be tested for CO-VID-19. Twenty-two patients required hospitalization and 15.4% died. In bivariate analysis, mortality was associated with older age (p = 0.03), cardiovascular disease (p = 0.05), chronic obstructive pulmonary disease (p = 0.05), and low hemoglobin levels (p = 0.006). Adjusted Cox regression showed that low hemoglobin levels at admission had 1.81 greater risk of mortality. CONCLUSIONS: Patients with CO-VID-19 infection and kidney disease confirmed by kidney biopsy presented a mortality of 15.4%. Swab test for COVID-19 was more likely to be performed in older, hypertensive, and immunosuppressed patients, those using RAS-blocking drugs, and those with gastrointestinal symptoms. Low hemoglobin is a risk factor for mortality.

Clinical characteristics and risk factors for severe COVID-19 in hospitalized kidney transplant recipients: A multicentric cohort study.

Kidney transplant recipients might be at higher risk for severe coronavirus disease 2019 (COVID-19). However, risk factors for relevant outcomes remain uncertain in this population. This is a multicentric kidney transplant cohort including 104 hospitalized patients between March 4 and April 17, 2020. Risk factors for death and acute respiratory distress syndrome (ARDS) were investigated, and clinical and laboratory data were analyzed. The mean age was 60 years. Forty-seven patients (54.8%) developed ARDS. Obesity was associated to ARDS development (OR 2.63; P = .04). Significant age differences were not found among patients developing and not developing ARDS (61.3 vs 57.8 years, P = .16). Seventy-six (73%) patients were discharged, and 28 (27%) died. Death was more common among the elderly (55 and 70.8 years, P < .001) and those with preexisting pulmonary disease (OR 2.89, P = .009). At admission, higher baseline lactate dehydrogenase (257 vs 358 IU/mL, P = .001) or ARDS conferred higher risk of death (HR 2.09, P = .044). In our cohort, ARDS was equally present among young and old kidney recipients. However, the elderly might be at higher risk of death, along with those showing higher baseline LDH at admission.

Plasma Exchange: An Effective Rescue Therapy in Critically Ill Patients With Coronavirus Disease 2019 Infection.

OBJECTIVES: Infection by severe acute respiratory syndrome coronavirus-2 can induce uncontrolled systemic inflammation and multiple organ failure. The aim of this study was to evaluate if plasma exchange, through the removal of circulating mediators, can be used as rescue therapy in these patients. DESIGN: Single center case series. SETTING: Local study. SUBJECTS: Four critically ill adults with coronavirus disease 19 pneumonia that failed conventional interventions. INTERVENTIONS: Plasma exchange. Two to six sessions (1.2 plasma volumes). Human albumin (5%) was used as the main replacement fluid. Fresh frozen plasma and immunoglobulins were administered after each session to avoid coagulopathy and hypogammaglobulinemia. MEASUREMENTS AND MAIN RESULTS: Serum markers of inflammation and macrophage activation. All patients showed a dramatic reduction in inflammatory markers, including the main cytokines, and improved severity scores after plasma exchange. All survived to ICU admission. CONCLUSIONS: Plasma exchange mitigates cytokine storm, reverses organ failure, and could improve survival in critically ill patients with coronavirus disease 2019 infection.

A Rejection Gene Expression Score in Indication and Surveillance Biopsies Is Associated with Graft Outcome.

Rejection-associated gene expression has been characterized in renal allograft biopsies for cause. The aim is to evaluate rejection gene expression in subclinical rejection and in biopsies with borderline changes or interstitial fibrosis and tubular atrophy (IFTA). We included 96 biopsies. Most differentially expressed genes between normal surveillance biopsies (n = 17) and clinical rejection (n = 12) were obtained. A rejection-associated gene (RAG) score was defined as its geometric mean. The following groups were considered: (a) subclinical rejection (REJ-S, n = 6); (b) borderline changes in biopsies for cause (BL-C, n = 13); (c) borderline changes in surveillance biopsies (BL-S, n = 12); (d) IFTA in biopsies for cause (IFTA-C, n = 20); and (e) IFTA in surveillance biopsies (IFTA-S, n = 16). The outcome variable was death-censored graft loss or glomerular filtration rate decline ≥ 30 % at 2 years. A RAG score containing 109 genes derived from normal and clinical rejection (area under the curve, AUC = 1) was employed to classify the study groups. A positive RAG score was observed in 83% REJ-S, 38% BL-C, 17% BL-S, 25% IFTA-C, and 5% IFTA-S. A positive RAG score was an independent predictor of graft outcome from histological diagnosis (hazard ratio: 3.5 and 95% confidence interval: 1.1-10.9; p = 0.031). A positive RAG score predicts graft outcome in surveillance and for cause biopsies with a less severe phenotype than clinical rejection.

Pilot monitoring study in patients with diabetic kidney disease using NORA application.

INTRODUCTION: Diabetic Kidney Disease (DKD) is the most common cause of end-stage chronic kidney disease (CKD), conditioning these patients to a worse renal prognosis and higher cardiovascular mortality and/or requirement for renal replacement therapy. The use of novel information and communication technologies (ICTs) focused on the field of health, may facilitates a better quality of life and disease control in these patients. Our objective is to evaluate the effect of monitoring DKD patients using NORA-app. MATERIAL AND METHODS: Prospective feasibility/validation study of NORA-app in patients with DKD stage G3bA3 or higher, followed in outpatient clinics of a tertiary care hospital. NORA-app is an application for smartphones designed to control risk factors, share educational medical information, communicate via chat with health professionals, increase treatment compliance (Morisky-Green), and collect patient reported outcomes such as anxiety and depression using HADs scale. Clinical-laboratory variables were collected at 3 months and compared to control patients who declined using NORA-app. RESULTS: From 01/01/2021 to 03/03/2022 the use of NORA-app was offered to 118 patients, 82 accepted and 36 declined (controls). After a mean follow-up period of 6,04 months and at the time of data extraction 71 (86.6%) NORA-app patients remain active users, 2 have completed the follow-up at one year and 9 are inactive (3 due to death and 6 due to non-locatable). There were no differences in baseline characteristics including Creatinine [2.1 (1.6-2.4) vs. 1.9 (1.5-2.5)] mg/dL and alb/creat [962 (475-1784) vs. 1036 (560-2183)] mg/gr between Nora and control patients respectively. The therapeutic compliance rate in the NORA-app group was 77%, improving at 90 days to 91%. Patients in the NORA-group showed significantly lower levels of alb/creat than controls (768(411-1971) mg/g Vs 2039 (974-3214) p = 0.047) at 90-day follow-up. CONCLUSIONS: In patients with DKD the use of NORA-app was maintained in the long-term, leading to high levels of treatment compliance, and achieving a better disease control. Our study suggests that the generalized use of ICTs may help in the personalized monitoring of these patients to delay the progression of kidney disease.

Role of SARS-CoV-2-specific memory B cells promoting immune protection after booster vaccination in solid organ transplantation.

Introduction: Solid organ transplant (SOT) recipients display weak seroconversion and neutralizing antibody (NAb) responses after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and remain at risk of severe coronavirus disease 2019 (COVID-19). While B-cell memory is the hallmark of serological immunity, its role in driving successful vaccine responses and providing immune protection in SOT patients remains unclear. Methods: We investigated the function and interplay of SARS-CoV-2-specific memory B cells (mBc), different cytokineproducing T cells, and cross-reactive NAb in driving seroconversion and protection against COVID-19 in two cohorts. First, we studied a large cohort of 148 SOT recipients and 32 immunocompetent individuals who underwent several vaccinations. Subsequently, we assessed 25 SOT patients participating in a randomized controlled trial to compare two different immunosuppressive strategies for allowing successful seroconversion and memory-cell responses after booster vaccination. Results: We corroborate previous findings that B- and T-cell memory responses are weaker and more delayed in SOT patients than in immunocompetent (IC) individuals; however, within the SOT cohort, we found that these responses are relatively stronger and more robust in patients not receiving mycophenolate mofetil (MMF)-based therapies. Anti- spike IgG titers strongly correlated with RBD-specific IgG-producing mBc, with both displaying broad viral cross reactivity. Prebooster SARS-CoV-2-specific mBc and IL-2- producing T cells accurately predicted Nab seroconversion (AUC, 0.828) and protection against severe COVID-19. While switching unresponsive SOT patients from calcineurin inhibitors (CNI)/MMF to a low-exposure CNI/mTOR-i regimen favored wider SARS-CoV-2-specific immune responses after a fourth booster vaccination, preformed RBD-specific mBc predicted NAb seroconversion. Discussion: Our study adds new insights into the pathobiology of immune memory and highlights the pivotal role of SARS-CoV-2-specific mBc in promoting immune protection inSOT patients.

The role of low health literacy in shared treatment decision-making in patients with kidney failure.

The classic paternalist medicine in nephrology has been modified to a shared decision-making model that clearly offers a benefit in patients with kidney disease. One of the cornerstones of shared treatment decision in patients with kidney failure is the understanding of kidney disease. As kidney disease is silent until advanced stages and is also an entity with a complex pathophysiology with little knowledge in the general population, its presence and understanding are difficult for most people. Health literacy (HL) plays a crucial role in the care of patients with kidney disease and the shared treatment decision. Limited HL has been associated with inefficient use of health services, non-compliance of medications, worse quality of life and increased mortality. In this review, we will address the importance of low HL in nephrology in terms of diagnosis, measurement, its effect on shared decision-making and how to increase it in people with kidney disease.

Epidemiology of Immune-Mediated Glomerulopathies before and after SARS-CoV-2 Vaccination: A Tertiary Referral Hospital Experience.

BACKGROUND: Vaccination is a known trigger for the appearance of immune-mediated glomerulopathies (IMG). The appearance of IMG after SARS-CoV-2 vaccination with suspected causality has been described. Our aim is to analyze the incidence of IMG flares before and after SARS-CoV-2 vaccination in our center. METHODS: All persons with native kidney biopsy (KB) from January 2019 to March 2022 in our center were included in the study. We compared the incidence of IMG before and after the start of vaccination. We also collected information about whether the patients had received a SARS-CoV-2 vaccine or have suffered from COVID in the six weeks before the IMG. We also evaluated the analytical characteristics of the outbreaks. RESULTS: A total of 386 KB were studied. Of them, 86/218 (39.4%) were IMG performed pre- and 85/168 (50.6%) post-SV (029). The incidence of idiopathic nephrotic syndrome (INS), studied separately, was also significantly increased post-vaccination (n = 18 (10.7%)) compared to pre-vaccination (n = 11 (5%)) (p = 0.036). There were no differences in the incidence of vasculitis or IgA nephropathy. Up to 17 (20%) flares occurred 6 weeks before SARS-CoV-2 vaccination and only 2 (2.4%) within the first 6 weeks after SARS-CoV-2 infection. Within those 17 flares, the most common diagnosis was IgAN (n = 5 (29.4%)); a total of 14 (82.4%) received an mRNA vaccine and 9 (52.9%) took place after the 1st vaccine dose. There were 13 cases of minimal change disease (MCD) with debut/recurrence pre-SV and 20 MCD with debut/recurrence post-SV (p = 0.002). CONCLUSIONS: The incidence of IMG, INS and MCD flares in our center increased significantly after SARS-CoV-2 vaccination. Importantly, 20% of IMG flares took place within the first 6 weeks after receiving a vaccine dose, with the first dose being the riskiest one and IgAN the most frequent diagnosis.