Glomerular Disease Research Articles

INF2 mutations cause kidney disease through a gain-of-function mechanism.

Heterozygosity for inverted formin-2 (INF2) mutations causes focal segmental glomerulosclerosis (FSGS) with or without Charcot-Marie-Tooth disease. A key question is whether the disease is caused by gain-of-function effects on INF2 or loss of function (haploinsufficiency). Despite established roles in multiple cellular processes, neither INF2 knockout mice nor mice with a disease-associated point mutation display an evident kidney or neurologic phenotype. Here, we compared responses to puromycin aminonucleoside (PAN)-induced kidney injury between INF2 R218Q and INF2 knockout mice. R218Q INF2 mice are susceptible to glomerular disease, in contrast to INF2 knockout mice. Colocalization, coimmunoprecipitation analyses, and cellular actin measurements showed that INF2 R218Q confers a gain-of-function effect on the actin cytoskeleton. RNA expression analysis showed that adhesion and mitochondria-related pathways were enriched in the PAN-treated R218Q mice. Both podocytes from INF2 R218Q mice and human kidney organoids with an INF2 mutation (S186P) recapitulate adhesion and mitochondrial phenotypes. Thus, gain-of-function mechanisms drive INF2-related FSGS and explain this disease's autosomal dominant inheritance.

Primary glomerular diseases and long-term adverse health outcomes: A nationwide cohort study.

Although glomerular diseases are the third most frequent cause of end-stage kidney disease worldwide, little is known about their long-term outcomes. In patients with chronic kidney disease (CKD) stage 3-5 enrolled in the Swedish Renal Registry, we compared risks of hospitalization, kidney replacement therapy (KRT), major cardiovascular events (MACE), and death of the four most frequent primary glomerular diseases (IgA nephropathy [IgAN], focal segmental glomerulosclerosis [FSGS], minimal change disease [MCD], and membranous nephropathy [MN]), and patients with CKD due to the most common non-communicable diseases (control-CKD). We identified 2396 patients with glomerular disease (97% biopsy-proven, 69% men, 57 years, eGFR 29mL/min/1.73m2, uACR 88mg/mmol, 1524 with IgAN, 398 FSGS, 94 MCD, and 380 MN) and 37,697 controls (64% men, 74 years, eGFR 25mL/min/1.73m2, uACR 23mg/mmol), mainly with diabetic nephropathy and nephroangiosclerosis. The median follow-up was 6.3 (3.3; 9.9) years. Compared with control-CKD, patients with primary glomerular diseases generally had a lower risk of hospitalization, MACE (adjusted hazard ratios [HRs] ranging from 0.44 to 0.88 depending on the etiology) and death (HRs ranging 0.45-0.76). Patients with IgAN and FSGS had a faster eGFR decline and a higher rate of KRT (HRs 1.26 [95%CI: 1.15-1.37] and 1.34 [1.15-1.57], respectively). Conversely, patients with MN and MCD had a lower KRT rate and slower eGFR decline. Despite having a lower relative risk of hospitalization, cardiovascular events and mortality, patients with IgAN and FSGS are at higher risk of CKD progression than the most common etiologies of CKD, emphasizing the need for more stringent treatment strategies in these patients.

The potential of pharmacotranscriptomic markers for predicting mycophenolic acid efficacy in children with steroid-dependent nephrotic syndrome

Nephrotic syndrome is one of the most common glomerular diseases in childhood. It is known that about half of patients with nephrotic syndrome develop dependence on steroid therapy, which requires the inclusion of a treatment regimen of selective immunosuppressive therapy. Mycophenolic acid (MPA) has been identified as a promising drug for steroid-resistant nephrotic syndrome, and it forms the basis of immunosuppressive therapy for this condition. The present study evaluates the importance of determining the expression of genes responsible for the metabolism of mycophenolic acid in patients with steroid-dependent nephrotic syndrome to maintain stable clinical and laboratory remission of the disease. The article demonstrates the significance and role of MDR1, UGT1A7, UGT1A9 and UGT2B7 gene expression as potential markers of increased risk of relapses and opens up prospects for the use of a transcriptomic approach to identify patients who require careful selection of pharmacotherapy. Although the results obtained are promising, changes in the expression of metabolic enzymes are only one of several factors that contribute to the effectiveness of treatment. Based on these data, it may be possible in the future to develop personalized monitoring strategies that can help tailor treatment to individual patients and increase its effectiveness.

Diagnosis and Treatment of Renal ANCA Vasculitis: A Summary of the Consensus Document of the Catalan Group for the Study of Glomerular Diseases (GLOMCAT)

The document provides a comprehensive overview of the diagnosis, monitoring, and treatment of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) with renal involvement, focusing on granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). It outlines the definitions, clinical presentation, histopathological classification, monitoring strategies, induction and maintenance treatments, as well as special considerations for relapsing, refractory, and frail patients with renal AAV. The document was prepared by the Catalan Group for the Study of Glomerular Diseases (GLOMCAT), which comprises nephrologists with extensive experience in the diagnosis and treatment of AAV patients. Several virtual and face-to-face meetings were held for coordination, section assignments, and content discussion. An exhaustive and systematic search of the literature was carried out, which included, among others, the following databases: PubMed, EMBASE, Cochrane Library, Google Scholar, and ClinicalTrials.gov, as well as the abstract books of national and international congresses. Overall, the document provides a comprehensive guide for clinicians managing patients with renal AAV, offering evidence-based recommendations for diagnosis, monitoring, and treatment across various clinical scenarios.

Immunofluorescence Use and Techniques in Glomerular Diseases – A Review

Background: Immunofluorescence (IF) studies play an essential role in the evaluation of medical renal biopsies. Particularly, in the study of renal glomerular diseases, where it provides fundamental data for the diagnosis, classification, and etiology of the glomerular pathologies. Diverse techniques may be used to optimize the utilization of IF studies, from variations on the test methodologies to expertise on the interpretation of the results and knowledge of potential pitfalls. Summary: This manuscript presents a brief review on the history of IF and its utilization in kidney pathology, followed by a description of the IF methods, including the use of immunofluorescence on paraffin embedded tissue (paraffin IF), and other novel techniques. Guidelines on how to best report IF findings are reviewed, along with a description of antibodies commonly used in glomerular diseases, highlighting their distribution within the normal kidney and potential pitfalls in interpretation. Finally, the use and interpretation of IF is discussed in more detail in individual entities on a range of glomerular diseases. Key Messages: Immunofluorescence is crucial for interpretation of renal biopsies and diagnosis of glomerular diseases. Knowledge of IF techniques, alternative procedures, its use and proper interpretation is essential for optimal utilization of IF in renal pathology, and this review proposes to serve as a simplified and practical guide on this topic.

Exploring the mediating role of immune cells in the pathogenesis of IgA nephropathy through the inflammatory axis of gut microbiota from a genomic perspective.

IgA nephropathy (IgAN) is a chronic glomerular disease characterized by the deposition of IgA antibodies in the kidney's mesangium. Its pathogenesis involves genetic, immune, and environmental factors, particularly within the mucosal immune system and gut microbiota. Immune cells play a central role in mediating these processes, which this study investigates using Mendelian Randomization (MR) to explore causal relationships among gut microbiota, inflammatory markers, blood cells, and immune cells in IgAN pathogenesis. We conducted a two-sample MR analysis using Genome-Wide Association Study (GWAS) summary data to assess the causal effects of gut microbiota, inflammatory markers, and blood cell traits on IgAN. Data sources included the FinnGen dataset for IgAN and relevant GWAS datasets for immune traits, blood cells, and inflammatory markers. Inverse variance weighting (IVW) was the primary MR method, supported by sensitivity analyses. We particularly examined the mediation effect of immune cells on these exposures' influence on IgAN. Significant associations were found between several factors and IgAN. Gut microbiota traits, such as Firmicutes E and Sporomusales, increased IgAN risk, while Citrobacter A and Herbinix reduced it. Inflammatory markers, including Interleukin-10 and Fibroblast Growth Factor 23, promoted IgAN onset. Blood cell traits like red blood cell perturbation response increased risk, while monocyte perturbation response was protective. Immune traits played a key mediating role, with Transitional %B cells reducing IgAN risk and CD28- CD25 + + CD8br %T cells increasing it. This study highlights the pivotal mediating role of immune cells in the interactions between gut microbiota, inflammatory markers, and IgAN risk. These findings identify potential biomarkers and therapeutic targets, providing new insights into the immune mechanisms underlying IgAN and opportunities for intervention.

The glomerular circadian clock temporally regulates basement membrane dynamics and the podocyte glucocorticoid response.

Kidney physiology shows diurnal variation, and a disrupted circadian rhythm is associated with kidney disease. However, it remains largely unknown whether glomeruli, the filtering units in the kidney, are under circadian control. Here, we investigated core circadian clock components in glomeruli, together with their rhythmic targets and modes of regulation. With clock gene reporter mice, cell-autonomous glomerular clocks which likely govern rhythmic fluctuations in glomerular physiology were identified. Using circadian time-series transcriptomic profiling, the first circadian glomerular transcriptome with 375 rhythmic transcripts, enriched for extracellular matrix and glucocorticoid receptor signaling ontologies, were identified. Subsets of rhythmic matrix-related genes required for basement membrane assembly and turnover, and circadian variation in matrix ultrastructure, coinciding with peak abundance of rhythmic basement membrane proteins, were uncovered. This provided multiomic evidence for interactions between glomerular matrix and intracellular time-keeping mechanisms. Furthermore, glucocorticoids, which are frequently used to treat glomerular disease, reset the podocyte clock and induce rhythmic expression of potential glomerular disease genes associated with nephrotic syndrome that included NPHS1 (nephrin) and NPHS2 (podocin). Disruption of the clock with pharmacological inhibition altered the expression of these disease genes, indicating an interplay between clock gene expression and key genes required for podocyte health. Thus, our results provide a strong basis for future investigations of the functional implications and therapeutic potential of chronotherapy in glomerular health and disease.

Evaluating the risk of cardiovascular events associated with different immunosuppression treatments for glomerular diseases.

Patients with glomerular disease are at high risk of cardiovascular disease but the contribution of immunosuppression to this risk is unclear. In this retrospective cohort study of 1912 patients (comprised of 759 with IgA nephropathy, 540 with focal segmental glomerulosclerosis, 387 with membranous nephropathy and 226 with minimal change disease) from British Columbia, Canada, we evaluated the association between exposure to specific immunosuppressive medications and a composite outcome including coronary artery, cerebrovascular and peripheral arterial events. Survival models were adjusted for baseline cardiovascular risk factors, type of glomerular disease, estimated glomerular filtration rate (eGFR) and proteinuria over time. During a median follow-up of 6.8 years, 212 patients (11.1%) experienced the primary outcome. Corticosteroid exposure was not significantly associated with the primary outcome after adjusting for cardiovascular risk factors. In fully adjusted models, cumulative calcineurin inhibitor exposure at modest (150-300 defined daily doses [DDD]) and higher (300 or more DDD) doses were associated with a 2-fold higher risk of cardiovascular events (hazard ratio 2.98, 95% confidence interval 1.27-6.95) and (2.78, 1.32-5.84), respectively. A peak daily dose of antimetabolite (azathioprine, mycophenolate mofetil and mycophenolate sodium) of 0.5 or more DDD was associated with higher risk of cardiovascular events after adjustment for baseline risk factors and type of glomerular disease, but not after adjusting for time-varying eGFR and proteinuria (1.70, 0.91-3.20). Each 10 grams of cumulative cyclophosphamide exposure was associated with a 1.5-fold higher risk of cardiovascular events in a fully adjusted model (1.46, 1.22-1.75) Thus, our findings suggest that immunosuppressive therapies used in the treatment of glomerular disease may have different cardiovascular risk profiles, which should be considered when deciding on immunosuppression for individual patients and as a safety endpoint in future clinical trials.

Mechanisms of podocyte injury in genetic kidney disease.

Glomerular diseases are a leading cause of chronic kidney disease worldwide. Both acquired and hereditary glomerulopathies frequently share a common final disease mechanism: disruption of the glomerular filtration barrier, podocyte injury, and ultimately podocyte death and detachment. Over 70 monogenic causes of proteinuric kidney disease have been identified, and most of these genes are highly expressed in podocytes, regulating key processes such as maintenance of the slit diaphragm, regulation of actin cytoskeleton remodeling, and modulation of downstream transcriptional pathways. Collectively, these are increasingly being referred to as hereditary "podocytopathies," in which podocyte injury is the central feature driving proteinuria and kidney dysfunction. In this review, we provide an overview of the monogenic podocytopathies and discuss the molecular mechanisms by which single-gene defects lead to podocyte injury and ultimately glomerulosclerosis. We review how advances in genomic technology and a better understanding of the cell biological basis of disease have led to the development of more targeted and personalized therapeutic strategies, including an overview of small molecule and gene therapy approaches.

What is the spectrum of kidney pathology associated with COVID-19?

Kidney involvement occurs in almost one third of patients hospitalised with coronavirus disease 2019 (COVID-19) and is associated with increased disease severity. This review aims to outline the spectrum of kidney pathology involved in COVID-19. Literature was reviewed systematically on the databases Medline OVID and Scopus in search of case reports, case series, cohort studies and autopsy studies of patients with COVID-19 who underwent kidney biopsies. Studies were published between August 2020 and November 2021. Fourteen studies consisting of 159 patients were included in this review. Acute tubular necrosis is the most common pathology followed by collapsing glomerulopathy, occurring in 40.1% and 28.9% of patients respectively. Of the 46 patients with collapsing glomerulopathy, 44 were of African descent with high-risk apolipoprotein L1 genotypes. Less common glomerular diseases include membranous nephropathy, secondary focal segmental glomerulosclerosis, minimal change disease and primary focal segmental glomerulosclerosis occurring in 5%, 4.4%, 3.1% and 2.5% of patients respectively. Glomerulonephritis occurred in a minority of patients. Direct viral infection has not been found as a definitive aetiology. Acute kidney injury occurs frequently in hospitalised COVID-19 patients and is associated with increased morbidity and mortality. The mechanisms underpinning acute kidney injury are multifactorial. Acute tubular necrosis is the most common. Collapsing glomerulopathy is the most common glomerular injury and is strongly linked to apolipoprotein L1 genotypes. Improved understanding of COVID-19-related kidney pathologies can guide treatment to improve patient outcomes and reduce progression of chronic kidney disease. The longitudinal impact of COVID-19-related kidney disease requires further research.

Combined transcriptome and proteome profiling reveal cell-type-specific functions of Drosophila garland and pericardial nephrocytes

Drosophila nephrocytes are specialised cells that share critical functional, morphological, and molecular features with mammalian podocytes. Accordingly, nephrocytes represent a preferred invertebrate model for human glomerular disease. Here, we established a method for cell-specific isolation of the two types of Drosophila nephrocytes, garland and pericardial cells, from animals of different developmental stages and ages. Mass spectrometry-based proteomics and RNA-Seq-based transcriptomics were applied to characterise the proteome and transcriptome of the respective cells in an integrated and complementary manner. We observed characteristic changes in the proteome and transcriptome due to cellular ageing. Furthermore, functional enrichment analyses suggested that larval and adult nephrocytes, as well as garland and pericardial nephrocytes, fulfil distinct physiological functions. In addition, the pericardial nephrocytes were characterised by transcriptomic and proteomic profiles suggesting an atypical energy metabolism with very low oxidative phosphorylation rates. Moreover, the nephrocytes displayed typical signatures of extensive immune signalling and showed an active antimicrobial response to an infection. Factor-specific comparisons identified novel candidate proteins either expressed and secreted by the nephrocytes or sequestered by them. The data generated in this study represent a valuable basis for a more specific application of the Drosophila model in analysing renal cell function in health and disease.

Proteinuria and proximal tubular epithelial cells: correlation between immunofluorescence, histology, and degree of proteinuria.

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.

Clinical findings, prognostic factors, and outcome of protein-losing nephropathy in cats: A retrospective study.

Primary glomerular disease resulting in protein-losing nephropathy (PLN) is an uncommon cause of chronic kidney disease in cats, yet is important to recognize because it warrants specific treatment that impacts outcome. Characterize clinicopathologic findings, prognostic indicators, and short- (≤30 days) and long-term survival of cats with PLN. Thirty-seven cats with naturally occurring PLN. Medical records of cats with PLN admitted to a veterinary teaching hospital were retrospectively reviewed. Median age was 3 years (range, 1.5-11.5 years) and 17/37 (46%) were males. Short-term survival was 57%. The estimated median survival time of all cats was 424 days (95% confidence interval [CI], 0-1098 days). Common clinical signs included lethargy (57%), edema (46%) and weight loss (35%). Edema was more common in short-term survivors compared with nonsurvivors (odds ratio [OR], 0.21; 95% CI, 0.05-0.86-20.4; P = .04). Serum creatinine concentration at presentation was negatively associated with long-term survival (OR, 1.3; 95% CI, 1.03-1.52; P = .01). Administration of immunosuppressive and antiproteinuric medications was more common among short-term survivors compared with nonsurvivors (18/20 [90%] vs 9/16 [56%]; OR, 7.0; 95% CI, 1.2-40.8; P = .05 and 17/20 [85%] vs 7/16 [44%]; OR, 7.3; 95% CI, 1.5-35.2; P = .01, respectively). Partial or complete remission was documented in 11/31 (36%) cats and was associated with both short (OR, 3.3; 95% CI, 1.7-6.5; P < .001) and long-term survival (P = .003). Cats with PLN have a guarded prognosis, but achieving remission improves outcome. Cats presented with edema rather than azotemia are more likely to respond to treatment.

Development and internal and external validation of a nomogram model for predicting the risk of chronic kidney disease progression in IgA nephropathy patients.

IgA nephropathy (IgAN) is the most common primary glomerular disease in chronic kidney disease (CKD), exhibiting significant heterogeneity in both clinical and pathological presentations. We aimed to explore the risk factors influencing short-term prognosis (≥90 days) and to construct a nomogram model for evaluating the risk of CKD progression in IgAN patients. Clinical and pathological data of patients diagnosed with IgAN through biopsy at two centers were retrospectively collected. Logistic regression was employed to analyze the training cohort dataset and identify the independent predictors to construct a nomogram model based on the final variables. The predictive model was validated both internally and externally, with its performance assessed using the area under the curve (AUC), calibration curves, and decision curve analysis. Out of the patients in the modeling group, 129 individuals (41.6%) did not achieve remission following 3 months of treatment, indicating a high risk of CKD progression. A multivariate logistic regression analysis demonstrated that body mass index, urinary protein excretion, and tubular atrophy/interstitial fibrosis were identified as independent predictors for risk stratification. A nomogram model was formulated utilizing the final variables. The AUCs for the training set, internal validation set, and external validation set were 0.746 (95% confidence intervals (CI) [0.691-0.8]), 0.764 (95% CI [0.68-0.85]), and 0.749 (95% CI [0.65-0.85]), respectively. The validation of the subgroup analysis also demonstrated a satisfactory AUC. This study developed and validated a practical nomogram that can individually predict short-term treatment outcomes (≥90 days) and the risk of CKD progression in IgAN patients. It provides reliable guidance for timely and personalized intervention and treatment strategies.

Clinicopathological Features of Membranous Nephropathy Complicated by IgA Nephropathy: A Retrospective Analysis of Seven Cases.

Aims/Background Both membranous nephropathy (MN) and immunoglobulin A nephropathy (IgAN) are immune complex-mediated glomerular diseases, but the concurrent occurrence of these two conditions in the same patient is not common, a phenomenon that is currently not supported by clinical data in terms of treatment and prognosis. This study explores the clinical and pathological characteristics, as well as the treatment outcomes, of patients affected by MN and IgAN simultaneously. Methods The clinical data, pathological features, and diagnostic and therapeutic information of seven cases of MN complicated by IgAN, treated between December 2015 and December 2022, were retrospectively analyzed. Results Among the seven cases, there were two male and five female patients, with an average age of 57.3 ± 9.2 years. All patients presented with clinical manifestations of proteinuria and edema upon admission, with an average 24-hour urine protein of 3716.6 ± 1519.4 mg/24 h. Phospholipase A2 receptor (PLA2R) expression was detected in all seven cases, and nephrotic syndrome was clinically diagnosed in five cases. Additionally, all seven cases showed microscopic hematuria, with intermittent gross hematuria in two cases. All seven patients included in this study underwent renal biopsy. After disease staging, the patients had MN stages I-III and IgAN stages II-III. Pathological findings revealed abnormal glomerular basement membrane (GBM) and diffuse immunoglobulin G (IgG) deposition in the subepithelial space, predominantly of the IgG4 subtype. Simultaneously, there was diffuse mesangial zone deposition of immunoglobulin A (IgA) to varying degrees, co-localization of complement component C3 and IgA, and mesangial cell proliferation. Treatment strategies included angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) in combination with steroids or immunosuppressive therapies such as tacrolimus, cyclophosphamide, and rituximab. After 2-6 months of treatment, all patients achieved complete remission with a favourable prognosis. Conclusion MN accompanied by IgAN tends to occur more frequently in middle-aged and elderly individuals, with a relatively low incidence. The latent feature of the comorbidities manifests as a form of IgAN superimposed on the background of MN. Utilizing ACEI or ARB in combination with steroids or various immunosuppressive therapies represents a potentially effective treatment strategy.

Therapeutic Profile of IgA Nephropathy Regarding Pharyngeal Kidney Theory

IgA nephropathy (IgAN) is the most common glomerular disease, which is one of the main causes of chronic kidney disease. The course of this disease is prolonged, and the condition is often recurrent, and most of the disease changes after respiratory, gastrointestinal, and urinary infections, and respiratory infections are the most common of the three, which makes the treatment more difficult. In Chinese medicine, there is no direct name for this disease, but according to its symptoms, it can be categorized as "hematuria", "edema", "urolithiasis", "slow kidney wind" and other diseases. The disease is often caused by the recurrence of exogenous infections. For the recurrence of this disease due to exogenous infection, Chinese medicine treats IgA nephropathy from the pharynx according to the theory of "pharyngeal and renal correlation", which has achieved good clinical efficacy, and this point of view has received more and more attention nowadays. This article focuses on the treatment of IgA nephropathy from the pharyngeal-renal theory.

Modeling a biofluid-derived extracellular vesicle surface signature to differentiate pediatric idiopathic nephrotic syndrome clinical subgroups

Idiopathic Nephrotic Syndrome (INS) is a common childhood glomerular disease requiring intense immunosuppressive drug treatments. Prediction of treatment response and the occurrence of relapses remains challenging. Biofluid-derived extracellular vesicles (EVs) may serve as novel liquid biopsies for INS classification and monitoring. Our cohort was composed of 105 INS children at different clinical time points (onset, relapse, and persistent proteinuria, remission, respectively), and 19 healthy controls. The expression of 37 surface EV surface markers was evaluated by flow cytometry in serum (n = 83) and urine (n = 74) from INS children (mean age = 10.1, 58% males) at different time points. Urine EVs (n = 7) and serum EVs (n = 11) from age-matched healthy children (mean age = 7.8, 94% males) were also analyzed. Tetraspanin expression in urine EVs was enhanced during active disease phase in respect to the remission group and positively correlates with proteinuria levels. Unsupervised clustering analysis identified an INS signature of 8 markers related to immunity and angiogenesis/adhesion processes. The CD41b, CD29, and CD105 showed the best diagnostic scores separating the INS active phase from the healthy condition. Interestingly, combining urinary and serum EV markers from the same patient improved the precision of clinical staging separation. Three urinary biomarkers (CD19, CD44, and CD8) were able to classify INS based on steroid sensitivity. Biofluid EVs offer a non-invasive tool for INS clinical subclassification and “personalized” interventions.

APOL1 Bi- and Monoallelic Variants and Chronic Kidney Disease in West Africans.

Apolipoprotein L1 gene (APOL1) variants are risk factors for chronic kidney disease (CKD) among Black Americans. Data are sparse on the genetic epidemiology of CKD and the clinical association of APOL1 variants with CKD in West Africans, a major group in the Black population. We conducted a case-control study involving participants from Ghana and Nigeria who had CKD stages 2 through 5, biopsy-proven glomerular disease, or no kidney disease. We analyzed the association of CKD with APOL1 variants among participants with high-risk genotypes (two APOL1 risk alleles) and those with low-risk genotypes (fewer than two APOL1 risk alleles) by fitting logistic-regression models that controlled for covariates, including clinical site, age, and sex. Among 8355 participants (4712 with CKD stages 2 through 5, 866 with glomerular diseases, and 2777 with no kidney disease), the prevalence of monoallelic APOL1 variants was 43.0% and that of biallelic APOL1 variants was 29.7%. Participants with two APOL1 risk alleles had higher odds of having CKD than those with one risk allele or no risk alleles (adjusted odds ratio, 1.25; 95% confidence interval [CI], 1.11 to 1.40), as well as higher odds of focal segmental glomerulosclerosis (adjusted odds ratio, 1.84; 95% CI, 1.30 to 2.61). Participants with one APOL1 risk allele had higher odds of having CKD than those with no risk alleles (adjusted odds ratio, 1.18; 95% CI, 1.04 to 1.33), as well as higher odds of focal segmental glomerulosclerosis (adjusted odds ratio, 1.61; 95% CI, 1.04 to 2.48). The inclusion of covariates did not modify the association of monoallelic and biallelic APOL1 variants with CKD or focal segmental glomerulosclerosis. In this study, monoallelic APOL1 variants were associated with 18% higher odds of CKD and 61% higher odds of focal segmental glomerulosclerosis; biallelic APOL1 variants were associated with 25% higher odds of CKD and 84% higher odds of focal segmental glomerulosclerosis. (Funded by the National Human Genome Research Institute and others.).

Kidney Health Consequences of Patients with Glomerulonephritis; Before and After SARS-COV2 Infection

Objective: The virus that causes severe acute respiratory syndrome (SARS-CoV-2) was first identified in Wuhan, China, in December 2019. Recent studies have proven that SARS-CoV-2 is also a nephrotrophic virus. Methods: Our study aimed to evaluate kidney function and general kidney health of patients with previously diagnosed glomerular diseases and follow-up after SARS-CoV-2 infection. For this purpose, the data of 36 patients who were diagnosed with and routinely followed up for glomerulonephritis and had SARS-CoV-2 infection at the Kocaeli University Faculty of Medicine Hospital nephrology outpatient clinics between January 2020 and January 2022 were examined before and after the infection. Results: No significant differences were observed in serum creatinine, estimated glomerular filtration rate, and 24-hour urine protein values after infection. There was an increase in platelet and albumin levels following the SARS-CoV-2 infection. A significant decrease was detected in 24-hour urine creatinine values. Conclusion: The results of the study showed that kidney function and general kidney health of patients with SARS-CoV-2 infection diagnosed with glomerulonephritis were not different when compared to their condition before SARS-CoV-2 infection.

Post-transplant glomerular diseases: update on pathophysiology, risk factors, and management strategies

Abstract In recent years, advancements in immunosuppressive medications and post-transplant management have led to a significant decrease in acute rejection rates in renal allografts and consequent improvement in short-term graft survival. In contrast, recent data have shown an increased incidence of post-transplant glomerular diseases, which currently represent a leading cause of allograft loss. Although pathogenesis is not fully understood, growing evidence supports the role of inherited and immunological factors and has identified potential pre- and post-transplant predictors. In this review, we illustrate recent advancements in the pathogenesis of post-transplant glomerular disease and the role of risk factors and immunological triggers. In addition, we discuss potential prevention and management strategies.