Membranoproliferative Glomerulonephritis over 20 Years at a Tertiary Referral Center in the UK.

Introduction: Membranoproliferative glomerulonephritis (MPGN) is a pattern of injury seen on kidney biopsy, with various underlying etiologies. The component types, including complement-mediated MPGN, are relatively rare. This study presents longitudinal real-world data over 20 years in a tertiary renal center in the UK. Methods: All patients with an MPGN pattern on kidney biopsy between 2000 and 2020 were identified. After applying exclusion criteria, 38 patients remained. Data including patient demographics, details of the renal histology from the kidney biopsy, baseline laboratory results, treatments received, and clinical outcomes including renal replacement therapy and death were collected from the organization's electronic patient record. Results: Twenty-eight of the cohort had immune complex-mediated MPGN, and 10 had complement-mediated MPGN (8 with C3 glomerulonephritis and 2 with dense deposit disease). Median follow-up was 72 months. Median age was 61 years. Overall, 60.5% were female, and 92.1% white. At presentation, median eGFR was 31.5 mL/min/1.73 m2 and uPCR 394 mg/mmol. Here, 78.9% received renin-angiotensin-aldosterone system inhibitors and 71.1% received any immunosuppression. In total, 47.4% progressed to ESKD and 50% died during follow-up. Conclusions: The study found an older patient population than typically reported. Poor outcomes were observed in the overall cohort with progression to ESKD and mortality both at almost 50%. This may be influenced by the older patient population. Individualized management of patients with an MPGN biopsy finding is paramount, with comprehensive evaluation for triggers and complement abnormalities. Going forward, registry enrolment and collaborative studies may enhance knowledge and outcomes.

Ultrasound-guided kidney biopsy: a ten-year retrospective single-center experience and the promising role of clinical hypnosis.

This retrospective analysis investigates the outcomes and complications of 682 kidney biopsies performed at ARNAS G. Brotzu from 2010 to 2021. Our findings indicate a minor complication rate of 9.1%, with severe complications being exceedingly rare at 0.3%. Age did not contribute to an increased risk, underscoring the procedure's safety across age groups. Clinical hypnosis was incorporated into the biopsy protocol in a subset of patients (n = 45) from April 2019 to December 2023. Over 90% of these patients reported no perception of the procedure, and 60% experienced no pain. According to STAY-Y test scores, this approach significantly reduced anxiety post-procedure (p = 0.001); no major or minor complications were observed in this group. While our study reaffirms the very low risk of severe complications in kidney biopsies, it also highlights the potential benefits of adjunct clinical hypnosis in enhancing patient comfort and cooperation during the procedure. This exploration opens a promising avenue for further investigation to improve patient experiences and procedural outcomes in kidney biopsies.

Drug-Related Glomerular Phenotypes: A Global Pharmacovigilance Perspective.

Introduction: Adverse drug reactions are a significant problem in modern society, stemming from the increase in prescribed medications, over-the-counter drugs, and overall polypharmacy. Glomerular disorders are one of the frequently reported renal conditions associated with medication use. VigiBase is a significant tool for evaluating events associated with drug use, and, to the authors' knowledge, no study has yet assessed this database to identify the primary medications associated with glomerular disorders. Materials and Methods: We collected data from VigiBase for 54 years and evaluated data based on global frequencies, disproportionality (IC025 values), nephrotoxic potential, and physiopathological mechanisms. Results: Over the evaluation period, 33.932.051 spontaneous notifications of adverse drug reactions reported in VigiBase were assessed, from which 106.775 notifications of drug-associated glomerular disorders were extracted. The isolated medications were classified as 'potential nephrotoxins' (47.0%), with 40% of the medications lacking scientific references to report any association with the development of glomerular disorders. Among the evaluated medications, Inotersen (IC025 of 8.3), Penicillamine (IC025 6.8), Bevacizumab (IC025 5.9) and Lenvatinib (IC025 5.4) were identified as having the strongest association with these glomerular disorders. For medications classified as 'non-nephrotoxic', a high disproportionality index was observed, suggesting drugs that might be considered as new potential nephrotoxins. Conclusions: Drug-induced glomerular disorders were significantly associated with medications that had no established nephrotoxic role but demonstrated a high disproportionality index in VigiBase. These newly alleged nephrotoxic drugs warrant further evaluation in dedicated studies to assess their true nephrotoxic potential.

Paraneoplastic Glomerular Diseases.

Paraneoplastic glomerular disease (PGD) develops from tumor cell products, leading to renal dysfunction. Unlike direct tumor effects, PGD illustrates the complex association between cancer and diverse clinical presentations and outcomes. Initially detected in a Hodgkin's disease patient, current research has defined diagnostic criteria based on PGD symptoms and cancer progression. PGDs, although rare (found in <1% of adult cancer patients with overt renal manifestations), are crucial, as they can signal cancer onset and frequently resist standard glomerulonephritis treatments. The emerging field of onconephrology studies this relationship between kidney disorders and cancers. The exact cause of many PGD cases remains unknown. This review examines PGDs, their clinicopathological features, related cancers, and mechanisms, emphasizing the need for early diagnosis and tailored treatment for kidney disease and linked cancer.

Network Pharmacology and Molecular Docking Validation to Explore the Pharmacological Mechanism of Zhuling Decoction against Nephrotic Syndrome.

BACKGROUND: In recent years, the incidence and prevalence of Nephrotic Syndrome (NS) have been increasing. Zhuling Decoction (ZLD), a classical Chinese medicine, has been clinically proven to be effective for the treatment of NS. However, its underlying mechanism and pharmacodynamic substances remain unclear. OBJECTIVE: This study aimed to explore the mechanism of action and chemical components of ZLD against NS using network pharmacology and molecular docking. METHODS: Traditional Chinese Medicine Systems Pharmacology (TCMSP), Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicines (BATMAN-TCM), and SwissTargetPrediction databases were used to screen the principal ingredients and the associated targets of ZLD. NS-related targets were obtained from the Online Mendelian Inheritance in Man (OMIM), GeneCards, Therapeutic Target Database (TTD), and Drugbank databases. Shared targets were derived by the intersection of ZLD- and NS-associated targets. Protein-interaction relationships were analyzed using the STRING database and Cytoscape. A visualized drug-active compound-target network of ZLD was established using Cytoscape. Analyses of gene enrichment were performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) methods by the Database for Annotation, Visualization, and Integrated Discovery (DAVID) database. Molecular docking was performed to assess the binding activity between active components and hub targets. RESULTS: Polyporusterone E, cerevisterol, alisol B, and alisol B 23-acetate were the primary potential ingredients of ZLD. HMGCR, HSD11B1, NOS2, NR3C1, and NR3C2 were the hub targets of ZLD against NS. Molecular docking showed that polyporusterone E, cerevisterol, and alisol B had high binding activities with targets HMGCR, HSD11B1, and NOS2. CONCLUSION: In summary, this study suggests that the main active compounds (polyporusterone E, cerevisterol, alisol B) may have important roles for ZLD acting against NS by binding to hub targets (HMGCR, HSD11B1, and NOS2) and modulating PI3K-Akt, Ras, MAPK, and HIF-1 signaling pathways.

Clinicopathological Characteristics and Disease Chronicity in Glomerular Diseases: A Decade-Long Study at Romania's Largest Kidney Biopsy Reference Center.

Glomerular diseases (GDs), significant causes of end-stage kidney disease, are better understood through epidemiological studies based on kidney biopsies (KBs), which provide important insights into their prevalence and characteristics. This study aims to analyze the clinicopathological features of GDs diagnosed from 2008 to 2017 at Romania's largest reference center. In this decade-long study, 1254 adult patients diagnosed with GDs were included. The local previously validated renal histopathological prognostic score was calculated for each KB using four histopathologic lesions: global glomerulosclerosis, tubular atrophy, interstitial fibrosis and fibrocellular/fibrous crescents. The mean patient age was 50 years, with a male predominance (57%). The primary referral reasons were nephrotic syndrome (46%), nephritic syndrome (37%), chronic kidney disease (12%), asymptomatic urinary abnormalities (4%), and acute kidney injury (1%). Immunoglobulin A nephropathy (IgAN) was the most frequently diagnosed GD (20%), aligning with frequencies reported in European registries. Diabetic glomerular nephropathy was the most common secondary GD (10%). It also presented the highest median renal histopathological prognostic score (2), indicating a poorer prognosis. Lower eGFR and higher proteinuria were independently associated with higher scores. This decade-long study highlights IgAN as the most frequent GD diagnosed by KB. Diabetic glomerular nephropathy was identified as the most common secondary GD. The renal histopathological prognostic score, notably high in diabetic glomerular nephropathy patients, was correlated with lower eGFR and higher proteinuria, underlining its clinical relevance.

Liver Disease-Associated Glomerulopathies.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infect a significant number of individuals globally and their extra-hepatic manifestations, including glomerular disease, are well established. Additionally, liver disease-associated IgA nephropathy is the leading cause of secondary IgA nephropathy with disease course varying from asymptomatic urinary abnormalities to progressive kidney injury. Herein we provide an updated review on the epidemiology, pathogenesis, clinical manifestations, and treatment of HBV- and HCV-related glomerulonephritis as well as IgA nephropathy in patients with liver disease. The most common HBV-related glomerulonephritis is membranous nephropathy, although membranoproliferative glomerulonephritis and podocytopathies have been described. The best described HCV-related glomerulonephritis is cryoglobulinemic glomerulonephritis occurring in about 30% of patients with mixed cryoglobulinemic vasculitis. The mainstay of treatment for HBV-GN and HCV-GN is antiviral therapy, with significant improvement in outcomes since the emergence of the direct-acting antivirals. However, cases with severe pathology and/or a more aggressive disease trajectory can be offered a course of immunosuppression, commonly anti-CD20 therapy, particularly in the case of cryoglobulinemic glomerulonephritis.

Challenges and Opportunities for the Clinical Translation of Spatial Transcriptomics Technologies.

Background: The first spatially resolved transcriptomics platforms, GeoMx (Nanostring) and Visium (10x Genomics) were launched in 2019 and were recognized as the method of the year by Nature Methods in 2020. The subsequent refinement and expansion of these and other technologies to increase -plex, work with formalin-fixed paraffin-embedded tissue, and analyze protein in addition to gene expression have only added to their significance and impact on the biomedical sciences. In this perspective, we focus on two platforms for spatial transcriptomics, GeoMx and Visium, and how these platforms have been used to provide novel insight into kidney disease. The choice of platform will depend largely on experimental questions and design. The application of these technologies to clinically sourced biopsies presents the opportunity to identify specific tissue biomarkers that help define disease etiology and more precisely target therapeutic interventions in the future. Summary: In this review, we provide a description of the existing and emerging technologies that can be used to capture spatially resolved gene and protein expression data from tissue. These technologies have provided new insight into the spatial heterogeneity of diseases, how reactions to disease are distributed within a tissue, which cells are affected, and molecular pathways that predict disease and response to therapy. Key Message: The upcoming years will see intense use of spatial transcriptomics technologies to better define the pathophysiology of kidney diseases and develop novel diagnostic tests to guide personalized treatments for patients.

Type I IFN in Glomerular Disease: Scarring beyond the STING.

The field of nephrology has recently directed a considerable amount of attention towards the stimulator of interferon genes (STING) molecule since it appears to be a potent driver of chronic kidney disease (CKD). STING and its activator, the cyclic GMP-AMP synthase (cGAS), along with intracellular RIG-like receptors (RLRs) and toll-like receptors (TLRs), are potent inducers of type I interferon (IFN-I) expression. These cytokines have been long recognized as part of the mechanism used by the innate immune system to battle viral infections; however, their involvement in sterile inflammation remains unclear. Mounting evidence pointing to the involvement of the IFN-I pathway in sterile kidney inflammation provides potential insights into the complex interplay between the innate immune system and damage to the most sensitive segment of the nephron, the glomerulus. The STING pathway is often cited as one cause of renal disease not attributed to viral infections. Instead, this pathway can recognize and signal in response to host-derived nucleic acids, which are also recognized by RLRs and TLRs. It is still unclear, however, whether the development of renal diseases depends on subsequent IFN-I induction or other processes involved. This review aims to explore the main endogenous inducers of IFN-I in glomerular cells, to discuss what effects autocrine and paracrine signaling have on IFN-I induction, and to identify the pathways that are implicated in the development of glomerular damage.

Non-Invasive Biomarkers for Diagnosis, Risk Prediction, and Therapy Guidance of Glomerular Kidney Diseases: A Comprehensive Review.

Effective management of glomerular kidney disease, one of the main categories of chronic kidney disease (CKD), requires accurate diagnosis, prognosis of progression, assessment of therapeutic efficacy, and, ideally, prediction of drug response. Multiple biomarkers and algorithms for the assessment of specific aspects of glomerular diseases have been reported in the literature. Though, the vast majority of these have not been implemented in clinical practice or are not available on a global scale due to limited access, missing medical infrastructure, or economical as well as political reasons. The aim of this review is to compile all currently available information on the diagnostic, prognostic, and predictive biomarkers currently available for the management of glomerular diseases, and provide guidance on the application of these biomarkers. As a result of the compiled evidence for the different biomarkers available, we present a decision tree for a non-invasive, biomarker-guided diagnostic path. The data currently available demonstrate that for the large majority of patients with glomerular diseases, valid biomarkers are available. However, despite the obvious disadvantages of kidney biopsy, being invasive and not applicable for monitoring, especially in the context of rare CKD etiologies, kidney biopsy still cannot be replaced by non-invasive strategies.

Complement Activation in Nephrotic Glomerular Diseases.

The nephrotic syndrome holds significant clinical importance and is characterized by a substantial protein loss in the urine. Damage to the glomerular basement membrane or podocytes frequently underlies renal protein loss. There is an increasing belief in the involvement of the complement system, a part of the innate immune system, in these conditions. Understanding the interactions between the complement system and glomerular structures continually evolves, challenging the traditional view of the blood-urine barrier as a passive filter. Clinical studies suggest that a precise inhibition of the complement system at various points may soon become feasible. However, a thorough understanding of current knowledge is imperative for planning future therapies in nephrotic glomerular diseases such as membranous glomerulopathy, membranoproliferative glomerulonephritis, lupus nephritis, focal segmental glomerulosclerosis, and minimal change disease. This review provides an overview of the complement system, its interactions with glomerular structures, and insights into specific glomerular diseases exhibiting a nephrotic course. Additionally, we explore new diagnostic tools and future therapeutic approaches.

Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of ANCA-Associated Vasculitis.

In 2021, the Kidney Disease: Improving Global Outcomes (KDIGO) Guideline for the Management of Glomerular Diseases was published. KDIGO is committed to providing the nephrology community with periodic updates, based on new developments for each disease. For patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), avacopan received regulatory approval in late 2021, leading to this KDIGO guideline update. In addition, the evidence supporting a lower-dose glucocorticoid induction regimen or even complete replacement of glucocorticoids has become stronger. Herein, an executive summary of the most important guideline changes from the AAV chapter is provided as a quick reference.

An Update on Current Therapeutic Options in IgA Nephropathy.

Immunoglobulin A nephropathy (IgAN) remains the leading cause of primary glomerular disease worldwide. Outcomes are poor with high rates of progressive chronic kidney disease and kidney failure, which contributes to global healthcare costs. Although this disease entity has been described, there were no disease-specific treatments until recently, with the current standard of care focusing on optimal supportive measures including lifestyle modifications and optimization of the renin-angiotensin-aldosterone blockade. However, with significant advances in the understanding of the pathogenesis of IgAN in the past decade, and the acceptance of surrogate outcomes for accelerated drug approval, there have been many new investigational agents tested to target this disease. As these agents become available, we envision a multi-pronged treatment strategy that simultaneously targets the consequences of ongoing nephron loss, stopping any glomerular inflammation, inhibiting pro-fibrotic signals in the glomerulus and tubulo-interstitium, and inhibiting the production of pathogenic IgA molecules. This review is an update on a previous review published in 2021, and we aim to summarize the developments and updates in therapeutic strategies in IgAN and highlight the promising discoveries that are likely to add to our armamentarium.

Implementation of Kidney Biopsy in One of the Poorest Countries in the World: Experience from Zinder Hospital (Niger).

Kidney biopsy (KB) has become essential in the nephrologist's approach to kidney diseases, both for diagnosis, treatment, and prognosis. Our objective is to describe the preliminary results of KBs in Niger, one of the poorest countries in the world. This is a descriptive cross-sectional study that took place over 36 months in the nephrology/dialysis department of the Zinder National Hospital. Biopsy results were obtained in less than 5 working days. Patients were responsible for covering the cost of the kidney biopsy. The data collected were analyzed using Epi Info V7 software. We performed 120 kidney biopsies during the study period. The average age of the patients was 35 years ± 15.4 [5-68]. The male/female sex ratio was 2:1. Patients' medical history included herbal medicine use in 33% of cases and high blood pressure in 27.5% of cases. Proteinuria was present at a rate of ≥3 g/24 h in 46.6% of them. The primary indication for kidney biopsy was glomerular syndrome in 62.5% of cases, including 50% with nephrotic syndrome. All kidney biopsies were performed with real-time ultrasound guidance, using an automatic gun fitted with a 16G needle. Regarding complications, macroscopic hematuria was present in 12.5% of cases. Inadequate kidney biopsy was infrequent (5.8% of cases). The most common findings were (i) glomerular diseases (58.4%), such as membranoproliferative glomerulonephritis (13.3%), focal-segmental glomerulosclerosis (10.6%), lupus nephritis (8.8%), minimal change disease (8%), and membranous nephropathy (2.7%), and (ii) tubulointerstitial changes (31.8%). Diabetic nephropathy was rare (2.6%), as was IgA nephropathy (0.9%). We have demonstrated that implementing a sustainable kidney biopsy program in a very poor country is feasible, thanks to the dedication of a specialized renal pathologist. Having a clear diagnosis can assist in properly treating these renal patients according to international guidelines, thereby delaying the progression to end-stage kidney disease.

Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of Lupus Nephritis.

The Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for the Management of Glomerular Diseases was published in 2021. Since then, the pace of drug development for glomerular diseases has accelerated, due in large part to rapidly accumulating insights into disease pathogenesis from genetic and molecular studies of afflicted patients. To keep the Glomerular Diseases Guideline as current as possible, KDIGO made a commitment to the nephrology community to provide periodic updates, based on new developments for each disease. After the 2021 guideline was published, two novel drugs received regulatory approval for the management of lupus nephritis, leading to the first KDIGO guideline update. Herein, an executive summary of the most important guideline changes from the Lupus Nephritis chapter is provided as a quick reference.

Central role of podocytes in mediating cellular cross talk in glomerular health and disease.

Podocytes are highly specialized epithelial cells that surround the capillaries of the glomeruli in the kidney. Together with the glomerular endothelial cells, these postmitotic cells are responsible for regulating filtrate from the circulating blood with their organized network of interdigitating foot processes that wrap around the glomerular basement membrane. Although podocyte injury and subsequent loss is the hallmark of many glomerular diseases, recent evidence suggests that the cell-cell communication between podocytes and other glomerular and nonglomerular cells is critical for the development and progression of kidney disease. In this review, we highlight these key cellular pathways of communication and how they might be a potential target for therapy in glomerular disease. We also postulate that podocytes might serve as a central hub for communication in the kidney under basal conditions and in response to cellular stress, which may have implications for the development and progression of glomerular diseases.

Early growth response 1 as a podocyte injury marker in human glomerular diseases.

Background: In human glomerular diseases, visualizing podocyte injury is desirable since podocytes do not regenerate and podocyte injury leads to podocyte loss. Herein, we investigated the utility of immunostaining for early growth response 1 (EGR1), which is expressed in injured podocytes from the early stages of injury in animal experiments, as a podocyte injury marker in human glomerular diseases. Methods: This study included 102 patients with biopsy-proven glomerular diseases between 2018 and 2021. The proportion of EGR1 expression in podocytes (%EGR1pod) was analyzed in relation to clinical and histopathological features, including glomerular and urinary podocyte-specific markers. Results: %EGR1pod correlated significantly with the urinary protein:creatinine ratio, urinary nephrin and podocin mRNA levels, and glomerular podocin staining (rho = 0.361, 0.514, 0.487 and -0.417, respectively; adjusted P = .002, <.001, <.001 and <.001, respectively). Additionally, %EGR1pod correlated with cellular/fibrocellular crescents (rho = 0.479, adjusted P <.001). %EGR1pod was high in patients with glomerulonephritis, such as immunoglobulin A nephropathy (IgAN), lupus nephritis and antineutrophil cytoplasmic antibody-associated glomerulonephritis, and in those with podocytopathies, such as membranous nephropathy and primary focal segmental glomerulosclerosis, while %EGR1pod was low in patients with minimal change disease. In a subgroup analysis of IgAN, %EGR1pod was higher in Oxford C1 patients than in C0 patients. However, unexpectedly, patients with higher %EGR1pod were more prone to attain proteinuria remission, suggesting that EGR1 in the context of IgAN reflects reversible early injury. Conclusions: Our findings indicate that EGR1 is a promising potential marker for identifying active early podocyte injury in human glomerular diseases.

Underlying Mechanisms and Treatment of Hypertension in Glomerular Diseases.

PURPOSE OF REVIEW: This review aims to explore the underlying mechanisms that lead to hypertension in glomerular diseases and the advancements in treatment strategies and to provide clinicians with valuable insights into the pathophysiological mechanisms and evidence-based therapeutic approaches for managing hypertension in patients with glomerular diseases. RECENT FINDINGS: In recent years, there have been remarkable advancements in our understanding of the immune and non-immune mechanisms that are involved in the pathogenesis of hypertension in glomerular diseases. Furthermore, this review will encompass the latest data on management strategies, including RAAS inhibition, endothelin receptor blockers, SGLT2 inhibitors, and immune-based therapies. Hypertension (HTN) and cardiovascular diseases are leading causes of mortality in glomerular diseases. The latter are intricately related with hypertension and share common pathophysiological mechanisms. Hypertension in glomerular disease represents a complex and multifaceted interplay between kidney dysfunction, immune-mediated, and non-immune-mediated pathology. Understanding the complex mechanisms involved in this relationship has evolved significantly over the years, shedding light on the pathophysiological processes underlying the development and progression of glomerular disease-associated HTN, and is crucial for developing effective therapeutic strategies and improving patients' outcomes.