Frontiers in nephrology最新文献

Proteins are filtered from the blood through the glomerular filtration barrier. Filtered proteins are reabsorbed by proximal tubular epithelial cells (PTECs), which have been shown to possess the ability to regulate protein reabsorption. Histologically, these reabsorbed proteins are seen as tubular protein reabsorption droplets (TPRDs). Experimental studies indicate that PTECs play an important role in regulating proteinuria but the correlations between TPRD and the degree of proteinuria in human kidney biopsies have not been investigated in detail. Consecutive native kidney biopsies with non-proliferative glomerular disease performed at the OSUWMC for a 1-year period were analyzed. Cases with acute glomerular diseases and inadequate biopsies were excluded. The staining intensity and the percentage of TPRDs, as well as other morphologic parameters, were assessed. A total of 109 kidney biopsies were included in the study. A reverse correlation was identified between the percentage of albumin TPRDs and proteinuria (p = 0.047). There were positive correlations between proteinuria and the staining intensity for IgG TPRDs (p = 0.05) and the degree of acute tubular necrosis (ATN) (p = 0.015). In patients with no ATN, positive correlations between proteinuria and albumin and IgG TPRDs were seen, whereas in patients with ATN, these correlations were lost. A positive correlation was seen between proteinuria and chronic kidney injury. A strong correlation was noted between the degree of proteinuria and podocyte foot process effacement. Our data indicate that PTECs regulate proteinuria by absorbing proteins from the urine filtrate. Therefore, based on the human renal biopsy material, our study confirms that well-functioning renal PTECs play an important role in the regulation of proteinuria.

Introduction: Circulating anti-podocyte antibodies have been proposed as potential factors contributing to increased permeability in primary podocytopathies, such as Minimal Change Disease (MCD) and Focal Segmental Glomerulosclerosis (FSGS). The aim of the study was to to assess the levels of antibodies targeting synaptopodin and annexin 1 in the blood serum of patients diagnosed with nephrotic syndrome, with the aim of evaluating their potential utility in diagnosing primary podocytopathies and predicting therapeutic response.

Methods: The study included a total of 72 patients diagnosed with nephrotic syndrome, alongside 21 healthy subjects for comparison. Among the patients, 38 were diagnosed with FSGS, 12 with MCD, and 22 with MN. The levels of anti-synaptopodin and anti-annexin-1 antibodies were quantified using Enzyme-Linked Immunosorbent Assay.

Results: The levels of antibodies to annexin 1 and anti-synaptopodin in the blood were found to be higher in patients diagnosed with MCD and FSGS compared to those with MN and healthy individuals. The elevated levels of antibodies to annexin 1 and synaptopodin showed area under the curve values of 0.826 (95% CI 0.732-0.923) and 0.827 (95% CI 0.741-0.879), respectively. However, a model incorporating both antibodies demonstrated higher sensitivity (80.9%) and specificity (81.3%) with an AUC of 0.859 (95% CI 0.760-0.957). Notably, serum levels of annexin 1 and anti-synaptopodin antibodies did not predict the response to prednisolone and/or CNI therapy.

Discussion: Levels of antibodies targeting synaptopodin and annexin 1 were notably elevated in patients diagnosed with MCD and FSGS compared to those with MN and healthy controls. A panel comprising both antibodies demonstrated moderate to high sensitivity and specificity for diagnosis MCD or FSGS.

C3 glomerulopathy (C3G) is an ultra-rare complement-mediated kidney disease caused by to the deregulation of the alternative pathway (AP) of proximal complement. Consequently, all effector loops of the complement are active and can lead to pathologies, such as C3a- and C5a-mediated inflammation, C3b opsonization, surface C3b-mediated AP C3 convertase assembly, C3 cleavage product deposition in the glomerulus, and lytic C5b-9/MAC cell damage. The most common pathologic mechanisms are defective chronic alternative pathway deregulation, mostly occurring in the plasma, often causing C3 consumption, and chronic complement-mediated glomerular damage. C3G develops over several years, and loss of renal function occurs in more than 50% of patients. C3G is triggered by both genetic and autoimmune alterations. Genetic causes include mutations in individual complement genes and chromosomal variations in the form of deletions and duplications affecting genes encoding complement modulators. Many genetic aberrations result in increased AP C3 convertase activity, either due to decreased activity of regulators, increased activity of modulators, or gain-of-function mutations in genes encoding components of the convertase. Autoimmune forms of C3G do also exist. Autoantibodies target individual complement components and regulators or bind to neoepitopes exposed in the central alternative pathway C3 convertase, thereby increasing enzyme activity. Overactive AP C3 convertase is common in C3G patients. Given that C3G is a complement disease mediated by defective alternative pathway action, complement blockade is an emerging concept for therapy. Here, we summarize both the causes of C3G and the rationale for complement inhibition and list the inhibitors that are being used in the most advanced clinical trials for C3G. With several inhibitors in phase II and III trials, it is expected that effectice treatment for C3G will become availabe in the near future.

Desidustat is a small molecule inhibitor of hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) discovered and developed by Zydus Lifesciences for the treatment of anemia associated with chronic kidney disease (CKD). This review summarizes the preclinical and clinical profile of desidustat which led to its approval and clinical use in India.

Introduction: This study aimed to describe the clinical course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with glomerular diseases (GDs) and its impact on the probability of relapse.

Methods: Patients with biopsy-proven GD and positive PCR test for SARS-CoV-2 from glomerular clinics across Greece were studied retrospectively. Those who received the GD diagnosis after the SARS-CoV-2 vaccination or coronavirus disease 2019 (COVID-19) or ended in ESKD prior to infection were excluded. Demographics, histopathological diagnoses, past medical history, immunosuppression, and GD activity status were recorded.

Results: A total of 219 patients with GDs and documented SARS-CoV-2 infection were included. The mean time from the diagnostic kidney biopsy to SARS-CoV-2 infection was 67.6 ( ± 59.3) months. Among the participants, 82.5% had been vaccinated against SARS-CoV-2 with three doses (range: 2.5-3) without subsequent GD reactivation in 96.2% of them. Twenty-two patients (10%) were hospitalized for COVID-19 and one (0.5%) required mechanical ventilation. Four (1.8%) died due to COVID-19 and one (0.5%) had long COVID-19 symptoms. Among patients in remission prior to SARS-CoV-2 infection, 22 (11.2%) experienced a GD relapse within 2.2 (range: 1.5-3.7) months from the diagnostic test. The relapse-free survival after COVID-19 was significantly shorter for patients with minimal change disease, pauci-immune glomerulonephritis, and focal segmental glomerulosclerosis. No difference was observed in the relapse-free survival post-COVID-19 based on the history of SARS-CoV-2 vaccination.

Conclusions: SARS-CoV-2 infection appears to have a symptomatic but uncomplicated sequence in vaccinated patients with GDs, with a significant impact on the clinical course of GD, associated with an increased probability of relapse in certain histopathological types.

Objectives: The Inside CKD programme implemented a microsimulation modelling approach to project the clinical and economic burden of chronic kidney disease (CKD) between 2024 and 2027 in Hungary.

Methods: Using the peer-reviewed Inside CKD microsimulation, a virtual Hungarian population was generated that was derived from national records, local demographic data and published epidemiological data. These inputs defined the likelihood of a change in health state for each individual as they progressed through the model in annual increments. Individual CKD status, including disease progression, cardiorenal complications and associated costs, was tracked annually to generate the population-level projections of the clinical and economic burden of CKD.

Results: By 2027, people with CKD were projected to constitute 13.3% of the Hungarian national population. The prevalence of heart failure, myocardial infarction and stroke in people with CKD were projected to remain consistently high, reaching 323 447, 69 188 and 120 118 by 2027, respectively. Kidney replacement therapy cases were predicted to remain high at 20 515 in 2024 and 22 325 in 2027, with associated costs increasing from 71.4 billion HUF in 2024 to 79.6 billion HUF in 2027. Total annual healthcare costs associated with treating CKD were projected to constitute 5.4% of the overall national healthcare budget in 2027.

Conclusions: Inside CKD demonstrates that the future burden of CKD in Hungary will be substantial unless current management strategies change. The high prevalence of undiagnosed CKD and associated cardiorenal complications highlight the urgent need for policy interventions focused on early diagnosis and timely intervention to mitigate the future burden of CKD.

Introduction: Renal transplant biopsies provide insights into graft health and support decision making. The current evidence on links between biopsy scores and transplant outcomes suggests there may be numerous factors affecting biopsy scores. Here we adopt measurement science approach to investigate the sources of uncertainty in biopsy assessment and suggest techniques to improve its robustness.

Methods: Histological assessments, Remuzzi scores, biopsy processing and clinical variables are obtained from 144 repeat biopsies originating from 16 deceased-donor kidneys. We conducted sensitivity analysis to find the morphometric features with highest discriminating power and studied the dependencies of these features on biopsy and stain type. The analysis results formed a basis for recommendations on reducing the assessment variability.

Results: Most morphometric variables are influenced by the biopsy and stain types. The variables with the highest discriminatory power are sclerotic glomeruli counts, healthy glomeruli counts per unit area, percentages of interstitial fibrosis and tubular atrophy as well as diameter and lumen of the worst artery. A revised glomeruli adequacy score is proposed to improve the robustness of the glomeruli statistics, whereby a minimum of 104 µm² of cortex tissue is recommended to keep type 1 and type 2 error probabilities below 0.15 and 0.2.

Discussion: The findings are transferable to several biopsy scoring systems. We hope that this work will help practitioners to understand the sources of statistical uncertainty and improve the utility of renal biopsy.

Purpose of symposium: From September 6 - 8 2022, the Life/2022 Membrane Symposium was held in Frankfurt, Germany, and transmitted live to a worldwide internet audience. The event was part of the Life/Nephrology Campus initiative, a continuous educational platform for the nephrology community to expand knowledge and share expertise on contemporary topics in chronic kidney disease. We describe recent questions and advances in the field, and we underline challenges in the care of dialysis patients and opportunities for integration of new findings into clinical practice to improve patient outcomes in end stage kidney disease patients.

Topics: Most patients with kidney failure are on maintenance hemodialysis (MHD). The scientific program of the symposium was developed around topics about the role, functional determinants, technical aspects, limitations, and clinical implications of membranes presently in use. International experts with clinical or technical expertise as well as scientific recognition within the nephrology community were asked to prepare their presentations based on their own experiences, perceptions, opinions, and sources of information. The symposium devoted a major portion to discussing novel approaches for improving membranes and treatment quality, including updates on innovative concepts that may could potentially transform the landscape of kidney replacement therapy for chronic kidney disease patients in the future.

Implications: The intent was to provide insights into current attention points for healthcare professionals new to the field of MHD, and to test a unique forum for continuing medical education integrating physician and patient experiences to promote changes in clinical practice. Furthermore, the symposium premiered a specifically developed mixed reality holographic 3D model to demonstrate recent dialyzer innovation diminishing protein fouling on membrane surfaces. As a continuous online educational platform for scientific exchange, this Life/2022 event provided online learning opportunities with on-demand content, with all symposium lectures freely available on nephrologycampus.com.

Point-of-care ultrasonography (POCUS) is gaining heightened significance in critical care settings as it allows for quick decision-making at the bedside. While computerized tomography is still considered the standard imaging modality for many diseases, the risks and delays associated with transferring a critically ill patient out of the intensive care unit (ICU) have prompted physicians to explore alternative tools. Ultrasound guidance has increased the safety of invasive procedures in the ICU, such as the placement of vascular catheters and drainage of collections. Ultrasonography is now seen as an extension of the clinical examination, providing quick answers for rapidly deteriorating patients in the ICU. The field of nephrology is increasingly acknowledging the value of diagnostic point-of-care ultrasound (POCUS). By employing multi-organ POCUS, nephrologists can address specific queries that arise during the diagnosis and treatment of patients with acute kidney injury. This approach aids in ruling out hydronephrosis and offers immediate information on hemodynamics, thereby consolidating patient data and facilitating the development of personalized treatment strategies.

Renal hypouricemia (RHUC) is a rare genetic disorder characterized by impaired uric acid reabsorption which leads to persistently low serum uric acid levels. This condition predisposes individuals to complications such as uric acid kidney stones and exercise-induced acute kidney injury (EIAKI). Although mutations in SLC22A12 and SLC2A9 are commonly implicated in RHUC, the precise pathophysiological mechanisms, particularly those contributing to AKI, remain incompletely understood. We report the case of a 30-year-old male who experienced recurrent episodes of EIAKI despite the absence of high-intensity exercise, suggesting the involvement of factors beyond the traditional risk. Genetic analysis confirmed the diagnosis of RHUC type 2 (RHUC2) and identified compound heterozygous variants of SLC2A9. Although these variants are not novel, this case contributes to the limited literature on RHUC2, particularly in male patients with recurrent EIAKI. These findings highlight the importance of maintaining a high index of suspicion for RHUC in cases of unexplained AKI, especially when recurrent episodes follow physical activity, and the need for targeted genetic testing for an accurate diagnosis. The genomic data related to this case are available in Mendeley Data: Vukkadala, Muralinath; Paladugu, Niranjana Rekha (2024), "Renal hypouricemia," Mendeley Data, V2, doi: 10.17632/7z84mkdgn9.2.