Primary Exposure to SARS-CoV-2 via Infection or Vaccination Determines Mucosal Antibody-Dependent ACE2 Binding Inhibition.

BACKGROUND: Mucosal antibodies play a critical role in preventing SARS-CoV-2 infections or reinfections by blocking the interaction of the receptor-binding domain (RBD) with the angiotensin-converting enzyme 2 (ACE2) receptor on the cell surface. In this study, we investigated the difference between the mucosal antibody response after primary infection and vaccination. METHODS: We assessed longitudinal changes in the quantity and capacity of nasal antibodies to neutralize the interaction of RBD with the ACE2 receptor using the spike protein and RBD from ancestral SARS-CoV-2 (Wuhan-Hu-1), as well as the RBD from the Delta and Omicron variants. RESULTS: Significantly higher mucosal IgA concentrations were detected postinfection vs postvaccination, while vaccination induced higher IgG concentrations. However, ACE2-inhibiting activity did not differ between the cohorts. Regarding whether IgA or IgG drove ACE2 inhibition, infection-induced binding inhibition was driven by both isotypes, while postvaccination binding inhibition was mainly driven by IgG. CONCLUSIONS: Our study provides new insights into the relationship between antibody isotypes and neutralization by using a sensitive and high-throughput ACE2 binding inhibition assay. Key differences are highlighted between vaccination and infection at the mucosal level, showing that despite differences in the response quantity, postinfection and postvaccination ACE2 binding inhibition capacity did not differ.

Isavuconazole as prophylaxis and therapy for invasive fungal diseases: a real-life observational study.

BACKGROUND: Isavuconazole is a relatively new antifungal agent indicated for the management of various invasive fungal diseases (IFDs), including invasive aspergillosis. Information on real-world experience with isavuconazole is scarce. This retrospective observational study aimed to describe the usage of isavuconazole in clinical practice with an in-depth evaluation of individual isavuconazole exposure. METHODS: Patients treated with isavuconazole were evaluated based on retrospective data, including therapeutic drug monitoring (TDM) data and efficacy and safety data. Additionally, we calculated the individual isavuconazole exposure described by the average AUC24 over the first 7 days of treatment by means of non-linear mixed-effects modelling and compared this with the currently desired lower target AUC of 60 mg·h/L. RESULTS: Ninety-nine patients treated with isavuconazole were evaluated. In our real-life cohort, isavuconazole was often deployed off-label in patients with non-classical host factors and infections with non-Aspergillus and non-Mucorales species. Isavuconazole was most often chosen for its safety profile, even after prior triazole treatment with manifestations of toxicity. TDM and subsequent dosage adjustments were frequently performed. The individual average AUC24 over 7 days was above 60 mg·h/L in 29 out of 77 (37.7%) patients. CONCLUSIONS: This overview provides practical insights that can aid clinicians in the management of their patients with IFD. Our study shows that isavuconazole was used in a diverse patient population and was well tolerated overall. Individual isavuconazole exposure reflected by the average AUC24 over the first 7 days of treatment was generally low and variable. Dosage adjustments following TDM were frequently performed. Our experience shows that isavuconazole is a feasible alternative after prior azole treatment.

Antibody and T-Cell Responses 6 Months After Coronavirus Disease 2019 Messenger RNA-1273 Vaccination in Patients With Chronic Kidney Disease, on Dialysis, or Living With a Kidney Transplant.

BACKGROUND: The immune response to COVID-19 vaccination is inferior in kidney transplant recipients (KTRs) and to a lesser extent in patients on dialysis or with chronic kidney disease (CKD). We assessed the immune response 6 months after mRNA-1273 vaccination in kidney patients and compared this to controls. METHODS: A total of 152 participants with CKD stages G4/5 (eGFR <30 mL/min/1.73 m2), 145 participants on dialysis, 267 KTRs, and 181 controls were included. SARS-CoV-2 Spike S1 specific IgG antibodies were measured using fluorescent bead-based multiplex-immunoassay, neutralizing antibodies to ancestral, Delta, and Omicron (BA.1) variants by plaque reduction, and T-cell responses by interferon-γ release assay. RESULTS: At 6 months after vaccination, S1-specific antibodies were detected in 100% of controls, 98.7% of CKD G4/5 patients, 95.1% of dialysis patients, and 56.6% of KTRs. These figures were comparable to the response rates at 28 days, but antibody levels waned significantly. Neutralization of the ancestral and Delta variants was detected in most participants, whereas neutralization of Omicron was mostly absent. S-specific T-cell responses were detected at 6 months in 75.0% of controls, 69.4% of CKD G4/5 patients, 52.6% of dialysis patients, and 12.9% of KTRs. T-cell responses at 6 months were significantly lower than responses at 28 days. CONCLUSIONS: Although seropositivity rates at 6 months were comparable to rates at 28 days after vaccination, significantly decreased antibody levels and T-cell responses were observed. The combination of low antibody levels, reduced T-cell responses, and absent neutralization of the newly emerging variants indicates the need for additional boosts or alternative vaccination strategies in KTRs. CLINICAL TRIALS REGISTRATION: NCT04741386.

The role of interleukin-21 in COVID-19 vaccine-induced B cell-mediated immune responses in patients with kidney disease and kidney transplant recipients.

T-cell-mediated help to B cells is required for the development of humoral responses, in which the cytokine interleukin (IL)-21 is key. Here, we studied the mRNA-1273 vaccine-induced SARS-CoV-2-specific memory T-cell IL-21 response, memory B cell response, and immunoglobulin (Ig)G antibody levels in peripheral blood at 28 days after the second vaccination by ELISpot and the fluorescent bead-based multiplex immunoassay, respectively. We included 40 patients with chronic kidney disease (CKD), 34 patients on dialysis, 63 kidney transplant recipients (KTR), and 47 controls. We found that KTR, but not patients with CKD and those receiving dialysis, showed a significantly lower number of SARS-CoV-2-specific IL-21 producing T cells than controls (P < .001). KTR and patients with CKD showed lower numbers of SARS-CoV-2-specific IgG-producing memory B cells when compared with controls (P < .001 and P = .01, respectively). The T-cell IL-21 response was positively associated with the SARS-CoV-2-specific B cell response and the SARS-CoV-2 spike S1-specific IgG antibody levels (both Pearson r = 0.5; P < .001). In addition, SARS-CoV-2-specific B cell responses were shown to be IL-21 dependent. Taken together, we show that IL-21 signaling is important in eliciting robust B cell-mediated immune responses in patients with kidney disease and KTR.

Convolutional Neural Networks for the Evaluation of Chronic and Inflammatory Lesions in Kidney Transplant Biopsies.

In kidney transplant biopsies, both inflammation and chronic changes are important features that predict long-term graft survival. Quantitative scoring of these features is important for transplant diagnostics and kidney research. However, visual scoring is poorly reproducible and labor intensive. The goal of this study was to investigate the potential of convolutional neural networks (CNNs) to quantify inflammation and chronic features in kidney transplant biopsies. A structure segmentation CNN and a lymphocyte detection CNN were applied on 125 whole-slide image pairs of periodic acid-Schiff- and CD3-stained slides. The CNN results were used to quantify healthy and sclerotic glomeruli, interstitial fibrosis, tubular atrophy, and inflammation within both nonatrophic and atrophic tubuli, and in areas of interstitial fibrosis. The computed tissue features showed high correlation with Banff lesion scores of five pathologists (A.A., A.Dend., J.H.B., J.K., and T.N.). Analyses on a small subset showed a moderate correlation toward higher CD3+ cell density within scarred regions and higher CD3+ cell count inside atrophic tubuli correlated with long-term change of estimated glomerular filtration rate. The presented CNNs are valid tools to yield objective quantitative information on glomeruli number, fibrotic tissue, and inflammation within scarred and non-scarred kidney parenchyma in a reproducible manner. CNNs have the potential to improve kidney transplant diagnostics and will benefit the community as a novel method to generate surrogate end points for large-scale clinical studies.

eHealth to Improve Psychological Functioning and Self-Management of People With Chronic Kidney Disease: A Randomized Controlled Trial.

OBJECTIVE: Psychological distress is common among patients with chronic kidney disease and can interfere with disease self-management. We assessed the effectiveness of the personalized E-GOAL electronic health care pathway with screening and cognitive-behavioral therapy including self-management support, aimed to treat psychological distress and facilitate self-management among people with chronic kidney disease not on dialysis ( N = 121). METHODS: Primary outcome of the open two-arm parallel randomized controlled trial in four Dutch hospitals was psychological distress at posttest directly after the intervention and at 3-month follow-up. Secondary outcomes were physical and mental health-related quality of life, self-efficacy, chronic disease self-management, and personalized outcomes, that is, perceived progress compared with the previous time point on functioning (e.g., mood or social functioning) and self-management (e.g., dietary or medication adherence) outcomes that were prioritized by each individual. RESULTS: Linear mixed-effects analyses showed no significant time-by-group interaction effects for psychological distress, health-related quality of life, self-efficacy, and chronic condition self-management, whereas analyses of covariance showed significantly more perceived progress in the intervention group at posttest on personally prioritized areas of functioning ( b = 0.46, 95% confidence interval = 0.07-0.85) and self-management ( b = 0.55, 95% confidence interval = 0.16-0.95), with Cohen d values of 0.46 and 0.54 (medium effects), respectively. Effects on personalized outcomes were maintained at follow-up. CONCLUSIONS: Compared with regular care only, the electronic health intervention did not reduce psychological distress, whereas personalized outcomes did improve significantly after intervention. Future studies could consider personalized outcomes that reflect individually relevant areas and treatment goals, matching person-tailored treatments. TRIAL REGISTRATION: Registered at the Netherlands Trial Register with study number NTR7555 ( https://trialsearch.who.int/Trial2.aspx?TrialID=NTR7555 ).

Preparing European Nephrology for the next pandemic: lessons from the ERACODA collaboration.

Owing to the vulnerability of patients with chronic kidney disease to infectious diseases, the coronavirus disease 2019 (COVID-19) pandemic has been particularly devastating for the nephrology community. Unfortunately, the possibility of future COVID-19 waves or outbreaks of other infectious diseases with pandemic potential cannot be ruled out. The nephrology community made tremendous efforts to contain the consequences of the COVID-19 pandemic. Despite this, the COVID-19 pandemic has highlighted several shortcomings in our response to the pandemic and has taught us important lessons that can be utilized to improve our preparedness for any future health crises of a similar nature. In this article we draw lessons from the European Renal Association COVID-19 Database (ERACODA) project, a pan-European collaboration initiated in March 2020 to understand the prognosis of COVID-19 in patients on kidney function replacement therapy. We discuss the challenges faced in generating timely and robust evidence for informed management of patients with kidney disease and give recommendations for our preparedness for the next pandemic in Europe. Limited collaboration, the absence of common data architecture and the sub-optimal quality of available data posed challenges in our response to COVID-19. Aligning different research initiatives, strengthening electronic health records, and involving experts in study design and data analysis will be important in our response to the next pandemic. The European Renal Association may take a leading role in aligning research initiatives via its engagement with other scientific societies, national registries, administrators and researchers.

"What matters to you?": The relevance of patient priorities in dialysis care for assessment and clinical practice.

BACKGROUND: Dialysis patients are confronted with numerous, complex problems, which make it difficult to identify individual patient's most prominent problems. The objectives of this study were to (1) identify dialysis patients' most prominent problems from a patient perspective and (2) to calculate disease-specific norms for questionnaires measuring these problems. METHODS: One hundred seventy-five patients treated with hemodialysis or peritoneal dialysis completed a priority list on several domains of functioning (e.g., physical health, mental health, social functioning, and daily activities) and a set of matching questionnaires assessing patient functioning on these domains. Patient priorities were assessed by calculating the importance ranking of each domain on the priority list. Subsequently, disease-specific norm scores were calculated for all questionnaires, both for the overall sample and stratified by patient characteristics. RESULTS: Fatigue was listed as patients' most prominent problem. Priorities differed between male and female patients, younger and older patients, and home and center dialysis patients, which was also reflected in their scores on the corresponding domains of functioning. Therefore, next to general norm scores, we calculated corrections to the general norms to take account of patient characteristics (i.e., sex, age, and dialysis type). CONCLUSIONS: Results highlight the importance of having attention for the specific priorities and needs of each individual patient. Adequate disease-specific, norm-based assessment is not only necessary for diagnostic procedures but is an essential element of patient-centered care: It will help to better understand and respect individual patient needs and tailor treatment accordingly.

The Clinical Frailty Scale as a triage tool for ICU admission of dialysis patients with COVID-19: an ERACODA analysis.

BACKGROUND: Several guidelines recommend using the Clinical Frailty Scale (CFS) for triage of critically ill coronavirus disease 2019 (COVID-19) patients. This study evaluates the impact of CFS on intensive care unit (ICU) admission rate and hospital and ICU mortality rates in hospitalized dialysis patients with COVID-19. METHODS: We analysed data of dialysis patients diagnosed with COVID-19 from the European Renal Association COVID-19 Database. The primary outcome was ICU admission rate and secondary outcomes were hospital and ICU mortality until 3 months after COVID-19 diagnosis. Cox regression analyses were performed to assess associations between CFS and outcomes. RESULTS: A total of 1501 dialysis patients were hospitalized due to COVID-19, of whom 219 (15%) were admitted to an ICU. The ICU admission rate was lowest (5%) in patients >75 years of age with a CFS of 7-9 and highest (27%) in patients 65-75 years of age with a CFS of 5. A CFS of 7-9 was associated with a lower ICU admission rate than a CFS of 1-3 [relative risk 0.49 (95% confidence interval 0.27-0.87)]. Overall, mortality at 3 months was 34% in hospitalized patients, 65% in ICU-admitted patients and highest in patients >75 years of age with a CFS of 7-9 (69%). Only 9% of patients with a CFS ≥6 survived after ICU admission. After adjustment for age and sex, each CFS category ≥4 was associated with higher hospital and ICU mortality compared with a CFS of 1-3. CONCLUSIONS: Frail dialysis patients with COVID-19 were less frequently admitted to the ICU. Large differences in mortality rates between fit and frail patients suggest that the CFS may be a useful complementary triage tool for ICU admission in dialysis patients with COVID-19.

Recovery of dialysis patients with COVID-19: health outcomes 3 months after diagnosis in ERACODA.

BACKGROUND: Coronavirus disease 2019 (COVID-19)-related short-term mortality is high in dialysis patients, but longer-term outcomes are largely unknown. We therefore assessed patient recovery in a large cohort of dialysis patients 3 months after their COVID-19 diagnosis. METHODS: We analyzed data on dialysis patients diagnosed with COVID-19 from 1 February 2020 to 31 March 2021 from the European Renal Association COVID-19 Database (ERACODA). The outcomes studied were patient survival, residence and functional and mental health status (estimated by their treating physician) 3 months after COVID-19 diagnosis. Complete follow-up data were available for 854 surviving patients. Patient characteristics associated with recovery were analyzed using logistic regression. RESULTS: In 2449 hemodialysis patients (mean ± SD age 67.5 ± 14.4 years, 62% male), survival probabilities at 3 months after COVID-19 diagnosis were 90% for nonhospitalized patients (n = 1087), 73% for patients admitted to the hospital but not to an intensive care unit (ICU) (n = 1165) and 40% for those admitted to an ICU (n = 197). Patient survival hardly decreased between 28 days and 3 months after COVID-19 diagnosis. At 3 months, 87% functioned at their pre-existent functional and 94% at their pre-existent mental level. Only few of the surviving patients were still admitted to the hospital (0.8-6.3%) or a nursing home (∼5%). A higher age and frailty score at presentation and ICU admission were associated with worse functional outcome. CONCLUSIONS: Mortality between 28 days and 3 months after COVID-19 diagnosis was low and the majority of patients who survived COVID-19 recovered to their pre-existent functional and mental health level at 3 months after diagnosis.

Hyperhydration with cisplatin does not influence pemetrexed exposure.

Pemetrexed is a cytotoxic drug for first-line treatment of lung cancer. It is often combined with other anticancer drugs such as cisplatin or carboplatin. In clinical practice, hyperhydration regimens are applied to overcome cisplatin-related nephrotoxicity. As pemetrexed is almost completely eliminated from the body by the kidneys, hyperhydration can result in augmented clearance. Furthermore, administration of large quantities of fluid may increase the volume of distribution of pemetrexed. Pharmacokinetics and, thus, efficacy and toxicity may be influenced by hyperhydration. This has not yet been properly studied. We performed a population pharmacokinetic analysis to assess hyperhydration as a covariate for pemetrexed clearance and for volume of distribution A relevant change was defined as >25% increase in clearance or volume of distribution. In our extensive dataset of 133 individuals, we found that hyperhydration did not significantly or relevantly explain variability in pemetrexed clearance (unchanged, P = .196) or volume of distribution (+7% change, P = .002), despite a power of >99% to detect a relevant change. Therefore, dose adjustments of pemetrexed are not required during hyperhydration with cisplatin.

Employment and ability to work after kidney transplantation in the Netherlands: The impact of preemptive versus non-preemptive kidney transplantation.

BACKGROUND: Work can have a major positive impact on health and wellbeing. Employment of kidney transplant recipients (KTR) of working age is much lower than in the general population. The first aim of this study was to examine the impact of a preemptive kidney transplantation (PKT) on employment, in addition to other possible influencing factors. The second aim was to explore differences in work ability, absenteeism and work performance among employed KTR with different types of transplantations. METHODS: A cross-sectional survey study was conducted between 2018 and 2019 in nine Dutch hospitals. PKT as potential predictor of employment was examined. Furthermore, work ability, absenteeism and loss of work performance were compared between employed preemptive recipients with a living donor (L-PKT) and non-preemptive recipients with a living donor (L-nPKT) and with a deceased donor (D-nPKT). RESULTS: Two hundred and twenty four KTR participated; 71% reported having paid work. Paid work was more common among PKT recipients (82% vs. 65% in L-nPKT and 55% in D-nPKT) and recipients who were younger (OR .950, 95%CI .913-.989), had no comorbidities (1 comorbidity: OR .397, 95%CI .167-.942; 2 comorbidities: OR .347, 95%CI .142-.844), had less fatigue (OR .974, 95%CI .962-.987) and had mentally demanding work tasks (only in comparison with physically demanding tasks, OR .342, 95%CI .145-.806). If recipients were employed, D-nPKT recipients worked fewer hours (mean 24.6±11.3 vs. PKT 31.1±9.6, L-nPKT 30.1±9.5) and D-nPKT and L-nPKT recipients received more often supplemental disability benefits (32 and 33.3%, respectively) compared to PKT recipients (9.9%). No differences were found for self-reported ability to work, sick leave (absenteeism) and loss of work performance with the exception of limitations in functioning at work. CONCLUSIONS: Preemptive kidney transplantation recipients with a kidney from a living donor are employed more often, work more hours per week (only in comparison with D-nPKT) and have a partial disability benefit less often than nPKT recipients. More knowledge regarding treatments supporting sustainable participation in the labor force is needed as work has a positive impact on recipients' health and wellbeing and is also beneficial for society as a whole.

Kidney transplantation or dialysis in older adults-an interview study on the decision-making process.

BACKGROUND: In older patients with end-stage kidney disease (ESKD), the choice between kidney transplantation (KT) and dialysis may be more complex than in younger patients because of a higher prevalence of comorbidities and frailty. This study aims to provide greater insight into the current decision-making process by exploring the expectations, experiences and health outcome priorities of all stakeholders. METHODS: We performed semi-structured interviews with patients ≥65 years with ESKD (eGFR <15 ml/min/1.73m2, KT recipient or treated with dialysis), patients' relatives and healthcare professionals (nephrologists, nurses and medical social workers). Interviews were conducted until data saturation and thematically analysed. RESULTS: We performed 36 interviews (patients n = 18, relatives n = 5, healthcare professionals n = 13). Thematic analysis revealed five themes. Older patients' health outcome priorities were mostly related to quality of life (QOL). Individual older patients showed marked differences in the preferred level of engagement during the decision-making process (varying from 'wants to be in the lead' to 'follows the nephrologist') and in informational needs (varying from evidence-based to experience-based). On the contrary, healthcare professionals were quite unanimous on all aspects. They focused on determining eligibility for KT as start of the decision-making process, on clear and extensive information provision and on classical, medical outcomes. CONCLUSIONS: The decision-making process could benefit from early identification of older patients' values, needs and health outcome priorities, in parallel with assessment of KT eligibility and before discussing the treatment options, and the explicit use of this information in further steps of the decision-making process.

Quantitative assessment of inflammatory infiltrates in kidney transplant biopsies using multiplex tyramide signal amplification and deep learning.

Delayed graft function (DGF) is a strong risk factor for development of interstitial fibrosis and tubular atrophy (IFTA) in kidney transplants. Quantitative assessment of inflammatory infiltrates in kidney biopsies of DGF patients can reveal predictive markers for IFTA development. In this study, we combined multiplex tyramide signal amplification (mTSA) and convolutional neural networks (CNNs) to assess the inflammatory microenvironment in kidney biopsies of DGF patients (n = 22) taken at 6 weeks post-transplantation. Patients were stratified for IFTA development (<10% versus ≥10%) from 6 weeks to 6 months post-transplantation, based on histopathological assessment by three kidney pathologists. One mTSA panel was developed for visualization of capillaries, T- and B-lymphocytes and macrophages and a second mTSA panel for T-helper cell and macrophage subsets. The slides were multi spectrally imaged and custom-made python scripts enabled conversion to artificial brightfield whole-slide images (WSI). We used an existing CNN for the detection of lymphocytes with cytoplasmatic staining patterns in immunohistochemistry and developed two new CNNs for the detection of macrophages and nuclear-stained lymphocytes. F1-scores were 0.77 (nuclear-stained lymphocytes), 0.81 (cytoplasmatic-stained lymphocytes), and 0.82 (macrophages) on a test set of artificial brightfield WSI. The CNNs were used to detect inflammatory cells, after which we assessed the peritubular capillary extent, cell density, cell ratios, and cell distance in the two patient groups. In this cohort, distance of macrophages to other immune cells and peritubular capillary extent did not vary significantly at 6 weeks post-transplantation between patient groups. CD163+ cell density was higher in patients with ≥10% IFTA development 6 months post-transplantation (p < 0.05). CD3+CD8-/CD3+CD8+ ratios were higher in patients with <10% IFTA development (p < 0.05). We observed a high correlation between CD163+ and CD4+GATA3+ cell density (R = 0.74, p < 0.001). Our study demonstrates that CNNs can be used to leverage reliable, quantitative results from mTSA-stained, multi spectrally imaged slides of kidney transplant biopsies.

Implementation of the kidney team at home intervention: Evaluating generalizability, implementation process, and effects.

Research has shown that a home-based educational intervention for patients with chronic kidney disease results in better knowledge and communication, and more living donor kidney transplantations (LDKT). Implementation research in the field of renal care is almost nonexistent. The aims of this study were (1) to demonstrate generalizability, (2) evaluate the implementation process, and (3) to assess the relationship of intervention effects on LDKT-activity. Eight hospitals participated in the project. Patients eligible for all kidney replacement therapies (KRT) were invited to participate. Effect outcomes were KRT-knowledge and KRT-communication, and treatment choice. Feasibility, fidelity, and intervention costs were assessed as part of the process evaluation. Three hundred and thirty-two patients completed the intervention. There was a significant increase in KRT-knowledge and KRT-communication among participants. One hundred and twenty-nine out of 332 patients (39%) had LDKT-activity, which was in line with the results of the clinical trials. Protocol adherence, knowledge, and age were correlated with LDKT-activity. This unique implementation study shows that the results in practice are comparable to the previous trials, and show that the intervention can be implemented, while maintaining quality. Results from the project resulted in the uptake of the intervention in standard care. We urge other countries to investigate the uptake of the intervention.

COVID-19-related mortality in kidney transplant and dialysis patients: results of the ERACODA collaboration.

BACKGROUND: Patients on kidney replacement therapy comprise a vulnerable population and may be at increased risk of death from coronavirus disease 2019 (COVID-19). Currently, only limited data are available on outcomes in this patient population. METHODS: We set up the ERACODA (European Renal Association COVID-19 Database) database, which is specifically designed to prospectively collect detailed data on kidney transplant and dialysis patients with COVID-19. For this analysis, patients were included who presented between 1 February and 1 May 2020 and had complete information available on the primary outcome parameter, 28-day mortality. RESULTS: Of the 1073 patients enrolled, 305 (28%) were kidney transplant and 768 (72%) dialysis patients with a mean age of 60 ± 13 and 67 ± 14 years, respectively. The 28-day probability of death was 21.3% [95% confidence interval (95% CI) 14.3-30.2%] in kidney transplant and 25.0% (95% CI 20.2-30.0%) in dialysis patients. Mortality was primarily associated with advanced age in kidney transplant patients, and with age and frailty in dialysis patients. After adjusting for sex, age and frailty, in-hospital mortality did not significantly differ between transplant and dialysis patients [hazard ratio (HR) 0.81, 95% CI 0.59-1.10, P = 0.18]. In the subset of dialysis patients who were a candidate for transplantation (n = 148), 8 patients died within 28 days, as compared with 7 deaths in 23 patients who underwent a kidney transplantation <1 year before presentation (HR adjusted for sex, age and frailty 0.20, 95% CI 0.07-0.56, P < 0.01). CONCLUSIONS: The 28-day case-fatality rate is high in patients on kidney replacement therapy with COVID-19 and is primarily driven by the risk factors age and frailty. Furthermore, in the first year after kidney transplantation, patients may be at increased risk of COVID-19-related mortality as compared with dialysis patients on the waiting list for transplantation. This information is important in guiding clinical decision-making, and for informing the public and healthcare authorities on the COVID-19-related mortality risk in kidney transplant and dialysis patients.

Histopathological examination of removed kidney allografts: Is it useful? A retrospective cohort study.

The incidence and relevance of histological findings in removed allografts is unknown. In this study, we investigated the outcome of routine histopathological examination of removed allografts. We performed a retrospective cohort study in patients with kidney graft failure ≥3 months after transplantation. In this cohort, 244 allograft nephrectomies were performed. We routinely sent removed grafts for histopathological examination. In 197 cases, a pathology report was available for analysis. In 21 of the 197 grafts, gross necrosis precluded adequate interpretation. Signs of rejection were reported in 163 of the remaining 176 allografts. Recurrences of the original disease were found in 13 cases. These were all known from prior biopsies. Relevant secondary findings were present in eight cases: renal cell carcinoma (n = 2), urothelial cell carcinoma, candida pyelonephritis (n = 2), post-transplant lymphoproliferative disease, polyomavirus inclusions, and membranous nephropathy. All conditions were diagnosed before graft nephrectomy, except for one case of papillary renal cell carcinoma of 0.8 cm. As expected, signs of acute and/or chronic rejection are the main histopathological finding in grafts that are removed after late graft failure. Unexpected secondary findings are very rare. Therefore, it is justifiable to restrict histopathological examination of removed kidney allografts to specific cases.

Deep Learning-Based Histopathologic Assessment of Kidney Tissue.

BACKGROUND: The development of deep neural networks is facilitating more advanced digital analysis of histopathologic images. We trained a convolutional neural network for multiclass segmentation of digitized kidney tissue sections stained with periodic acid-Schiff (PAS). METHODS: We trained the network using multiclass annotations from 40 whole-slide images of stained kidney transplant biopsies and applied it to four independent data sets. We assessed multiclass segmentation performance by calculating Dice coefficients for ten tissue classes on ten transplant biopsies from the Radboud University Medical Center in Nijmegen, The Netherlands, and on ten transplant biopsies from an external center for validation. We also fully segmented 15 nephrectomy samples and calculated the network's glomerular detection rates and compared network-based measures with visually scored histologic components (Banff classification) in 82 kidney transplant biopsies. RESULTS: The weighted mean Dice coefficients of all classes were 0.80 and 0.84 in ten kidney transplant biopsies from the Radboud center and the external center, respectively. The best segmented class was "glomeruli" in both data sets (Dice coefficients, 0.95 and 0.94, respectively), followed by "tubuli combined" and "interstitium." The network detected 92.7% of all glomeruli in nephrectomy samples, with 10.4% false positives. In whole transplant biopsies, the mean intraclass correlation coefficient for glomerular counting performed by pathologists versus the network was 0.94. We found significant correlations between visually scored histologic components and network-based measures. CONCLUSIONS: This study presents the first convolutional neural network for multiclass segmentation of PAS-stained nephrectomy samples and transplant biopsies. Our network may have utility for quantitative studies involving kidney histopathology across centers and provide opportunities for deep learning applications in routine diagnostics.

Latest developments in living kidney donation.

PURPOSE OF REVIEW: Although the first successful kidney transplantation 65 years ago was performed with a living donor kidney, the number of living donor kidney transplantations has increased especially during the last 2 decades. The enlargement of living donor programs was made possible by new modes of living donation and by expansion of the living donor pool. At the same time, the long-term risks of kidney donation have been better delineated. In this review, the latest developments on these topics are summarized. RECENT FINDINGS: While the results of ABO-incompatible living kidney transplantation are superior to those of deceased donor transplantation, recent meta-analyses show a reduced patient and graft survival as compared with ABO compatible transplantation as well as increased risk of severe infection and bleeding. Kidney paired donation programs can be extended by including compatible couples and by advanced donation, although the latter raises ethical concerns. Living donors appear to have a higher risk of end-stage renal disease and this is especially true for obese donors and probably also for black donors with an APOL1 high-risk genotype. The importance of psychosocial outcomes after living kidney donation is increasingly recognized. SUMMARY: Living donor kidney transplantation remains the optimal treatment option for patients with end-stage renal disease. To increase the donor pool, a well developed paired kidney donation program and sufficient reimbursement of costs associated with donation are essential ingredients. Other ways of expanding the donor pool, such as ABO-incompatible transplantation, use of higher risk donors, providing donors with financial incentives and advanced donation are associated with medical, ethical and logistical complications. There should be a careful selection and follow-up of living kidney donors with attention for medical consequences as well as for psychosocial outcomes.

Allocation to highly sensitized patients based on acceptable mismatches results in low rejection rates comparable to nonsensitized patients.

Whereas regular allocation avoids unacceptable mismatches on the donor organ, allocation to highly sensitized patients within the Eurotransplant Acceptable Mismatch (AM) program is based on the patient's HLA phenotype plus acceptable antigens. These are HLA antigens to which the patient never made antibodies, as determined by extensive laboratory testing. AM patients have superior long-term graft survival compared with highly sensitized patients in regular allocation. Here, we questioned whether the AM program also results in lower rejection rates. From the PROCARE cohort, consisting of all Dutch kidney transplants in 1995-2005, we selected deceased donor single transplants with a minimum of 1 HLA mismatch and determined the cumulative 6-month rejection incidence for patients in AM or regular allocation. Additionally, we determined the effect of minimal matching criteria of 1 HLA-B plus 1 HLA-DR, or 2 HLA-DR antigens on rejection incidence. AM patients showed significantly lower rejection rates than highly immunized patients in regular allocation, comparable to nonsensitized patients, independent of other risk factors for rejection. In contrast to highly sensitized patients in regular allocation, minimal matching criteria did not affect rejection rates in AM patients. Allocation based on acceptable antigens leads to relatively low-risk transplants for highly sensitized patients with rejection rates similar to those of nonimmunized individuals.