Glomerular disease frequencies by race, sex and region: results from the International Kidney Biopsy Survey

Essential role of kidney biopsy in diagnosing glomerular diseases amidst evolving biomarkers

The discussion on renal biopsies and biomarkers highlights the essential aspects of nephrology. Although novel diagnostic biomarkers are emerging, renal biopsy remains critical for accurate diagnosis and treatment owing to the lack of sufficiently validated biomarkers with high sensitivity and specificity. Puspitasari et al highlighted the significant changes in renal biopsy indications and histological outcomes before and after the coronavirus disease 2019 (COVID-19) pandemic, reflecting the complex interactions between clinical workflows, public health issues, and patient demographics. Although biomarkers are increasingly utilized in nephrology, their importance remains balanced with traditional practices. Advancements in precision medicine are exemplified by tests like plasma anti-phospholipase A2 receptor levels. However, the COVID-19 pandemic revealed significant vulnerabilities in nephrology services, emphasizing the necessity for adaptable and robust healthcare strategies to manage chronic conditions during global crises. In conclusion, while biomarkers are poised to assume a more prominent role in nephrology, the significance of renal biopsies and thorough histopathological analysis remains paramount in understanding complex disease processes and guiding personalized patient management. The ongoing integration of traditional diagnostic approaches with innovative biomarker strategies promises to improve patient care and long-term health outcomes.

Genotype distribution and clinical association SNP in IgA nephropathy patients: The role of macromolecular protein complements C3

The pathogenesis of IgA nephropathy is not fully understood. In recent years, the complement system has been paid more and more attention in the development of IgA nephropathy, in which the macromolecular protein complement C3 plays a particularly important role. The purpose of this study was to investigate genotype distribution and its correlation with clinical features in patients with IgA nephropathy, with special attention to the role of complement C3. A group of patients diagnosed with IgA nephropathy were selected for the study and clinical data, including medical history and laboratory results, were collected. The genotypic distribution of 8 SNPS (including rs2228570) associated with complement C3 was detected by SNP genotyping. Statistical analysis was also used to evaluate the correlation between different genotypes and clinical features. The results showed that there were significant differences in the genotype distribution of the 8 SNPS in IgA nephropathy patients, and the genotype of rs2228570 was higher in patients. Scatterplot analysis revealed an association between rs2228570 genotype and clinical features, especially renal immunofluorescence markers. Patients with different genotypes showed significant differences in renal function, proteinuria and other clinical manifestations, suggesting that complement C3 may play an important role in the pathological process of IgA nephropathy. This study showed that there was a significant correlation between macromolecular protein complement C3 and genotype distribution and clinical characteristics of patients with IgA nephropathy, suggesting that complement C3 may be a potential biomarker of IgA nephropathy and provide new ideas for its clinical management.

Population Risk Predictors of Major Adverse Kidney Events in Patients with Focal Segmental Glomerulosclerosis from the CURE-CKD Registry

Background

Predictors of major adverse kidney events (MAKE) in focal segmental glomerulosclerosis (FSGS) have not been previously explored within large, real-world populations. The study aim was to evaluate population-level predictors of MAKE for patients with FSGS from health system data.

Methods

The study population was derived from electronic health records from Providence and University of California Los Angeles Health. Cox proportional hazards models were used to estimate the effects of clinical and non-clinical variables including age, gender, race and ethnicity, health system, health insurance, healthcare utilization, estimated glomerular filtration rate (eGFR), diabetes, hypertension, and prescription medications as predictors of MAKE defined as: ≥40% eGFR decline, kidney failure (eGFR <15 mL/min/1.73 m2, administrative codes for kidney failure, dialysis, or transplant) and death.

Results

Adults with FSGS (N=629) were 54% (n=342) men and 53±17 (mean±SD) years old. Baseline eGFR was 60±30 mL/min/1.73 m2, while median (interquartile range) urine albumin/creatinine ratio (UACR) and urine protein/creatinine ratio (UPCR) were 1,430 (520-2,630) mg/g and 1.6 (0.5-3.9) g/g, respectively. Angiotensin converting enzyme inhibitors or angiotensin receptor blockers were prescribed to 76% (n=475), while corticosteroids and other immunomodulators were prescribed in 47% (n=297) and 12% (n=74), respectively. MAKE were observed in 42% (n=262) of study participants over a median of 2.9 (1.4-4.5) years. Higher hazard for MAKE was associated with above-median UACR or UPCR (HR [95% CI] (3.46 [2.28-5.23]) in patients with available measures, prescription for non-corticosteroid immunomodulator (1.87 [1.32-2.65]), non-commercial health insurance (1.78 [1.36-2.33]), hospitalization (1.64 [1.25-2.15]), lower eGFR per 10 mL/min/1.73 m2 1.25 [1.18-1.32]), number of outpatient visits (1.03 [1.01-1.05]) and lower hazard for MAKE was associated with older age (0.89 [0.82-0.98]).

Conclusions

Substantial loss of kidney function or kidney failure occurred in more than four in ten patients with FSGS by a median of three years. MAKE were predicted by unique population level factors, such as healthcare utilization and insurance type, which may help to identify patients with FSGS, who could most benefit from diagnostic testing and interventions to improve clinical outcomes.

CR1 variants contribute to FSGS susceptibility across multiple populations

Focal segmental glomerulosclerosis (FSGS) is a leading cause of nephrotic syndrome, with an annual incidence of 24 cases per million among African-Americans and 5 per million among European-Americans in the United States. It ranks as the second most common glomerular disease in Europe and Latin America and the fifth in Asia. We conducted a case-control study involving 726 FSGS cases and 13,994 controls from diverse ethnic backgrounds, using panel sequencing of ∼2,500 podocyte-expressed genes. Rare variant association tests confirmed known risk genes (KANK1, COLAPOL1) and identified a significant association with the CR1 gene. The CR1 variant rs17047661, which encodes the Sl1/Sl2 (R1601G) allele, was previously linked to cerebral malaria protection and is now identified as a risk variant for FSGS. This highlights an evolutionary trade-off between infectious disease resistance and kidney disease susceptibility, emphasizing the role of adaptive immunity in FSGS pathogenesis and potential therapeutic targets.

Novel Biomarkers as Non-Invasive Diagnostic Tools in IgA Nephropathy: A Comparative Study with Lupus Nephritis and Membranous Nephropathy

Rationale

The diagnostic value of endothelial-associated biomarkers in IgAN and their ability to differentiate it from other kidney diseases have not yet been clarified.

Objective

This study aimed to investigate the diagnostic value of endothelial-associated biomarkers in IgAN patients.

Methods and Results

This is a cross-sectional study involving 96 participants, with IgAN, LN, MN, and healthy subjects recruited in a 1:1:1:1 ratio. Seventy-five percent of the sample was used for developing a classification model, and the remaining 25% was used for constructing a validation cohort. Plasma levels of 12 endothelial-associated biomarkers were detected using multiplex immunoassay technology. Among all the biomarkers evaluated, VLA-4 and VEGFD were prioritized for distinguishing IgAN from other groups (p<0.001), with 85% classification accuracy. These two biomarkers also showed significant correlation with eGFR (VLA-4: r = - 0.291, P = 0.021; VEGFD: r = - 0.271, P = 0.031) and Gd-IgA1 (VLA-4: r = 0.403, P = 0.003; VEGFD: r = 0.412, P = 0.002). These two biomarkers also showed superior diagnostic efficacy (AUC=0.952 and 0.945) compared to Gd-IgA1 (AUC=0.736). Subgroup analysis of IgAN patients revealed clinically relevant effect sizes for the IgA and IgA/C3 ratios between high- and low-VLA-4 and VEGFD groups, with Hedges' g values of 0.962 and 0.819, respectively. The diagnostic efficacy of VLA-4 and VEGFD levels in IgAN was further validated in an independent cohort comprising 24 participants.

Conclusion

VLA-4 and VEGFD emerge as robust, non-invasive biomarkers for IgAN diagnosis and may play significant roles in the pathogenesis of IgAN.

Inflammation in glomerular diseases

The structural and functional integrity of glomerular cells is critical for maintaining normal kidney function. Glomerular diseases, which involve chronic histological damage to the kidney, are related to injury to glomerular cells such as endothelial cells, mesangial cells (MCs), and podocytes. When faced with pathogenic conditions, these cells release pro-inflammatory cytokines such as chemokines, inflammatory factors, and adhesion factors. These substances interact with glomerular cells through specific inflammatory pathways, resulting in damage to the structure and function of the glomeruli, ultimately causing glomerular disease. Although the role of inflammation in chronic kidney diseases is well known, the specific molecular pathways that result in glomerular diseases remain largely unclear. For a long time, it has been believed that only immune cells can secrete inflammatory factors. Therefore, targeted therapies against immune cells were considered the first choice for treating inflammation in glomerular disease. However, emerging research indicates that non-immune cells such as glomerular endothelial cells, MCs, and podocytes can also play a role in renal inflammation by releasing inflammatory factors. Similarly, targeted therapies against glomerular cells should be considered. This review aims to uncover glomerular diseases related to inflammation and pathways in glomerular inflammation, and for the first time summarized that non-immune cells in the glomerulus can participate in glomerular inflammatory damage by secreting inflammatory factors, providing valuable references for future strategies to prevent and treat glomerular diseases. More importantly, we emphasized targeted glomerular cell therapy, which may be a key direction for the future treatment of glomerular diseases.

Epidemiology of kidney biopsy from regional referral center in Romania: 10-year review

PURPOSE

To provide epidemiologic data on kidney biopsy from Romania.

METHODS

Retrospective observational study of kidney biopsy records for adult patients from a referral center in the north-western part of Romania, reported for 2014-2023.

RESULTS

556 biopsies were performed, corresponding to an incidence of 12 biopsies/m person-year with over 50% increase over the last reported year. Optimal core for optic microscopy was available in 81.4%, immunofluorescence was performed in 86.3%, and electron microscopy in 35.2% of patients. The mean age at biopsy was 47.12 years, and 53.8% were males. Indications for kidney biopsy were nephrotic syndrome in 63.1% of patients, nephritic in 25.9% of patients, asymptomatic urinary abnormalities in 2.9%, acute kidney injury/ rapid progressive renal failure in 3.6%, and chronic kidney disease in 1.4%. The most frequent diagnostic categories were membranous nephritis (14.7%), IgA nephropathy (13.9%), focal segmental glomerulosclerosis (11,1%), minimal change disease (12,2%), lupus nephritis (10,9%), vasculitis (7.6%), and membranoproliferative glomerulonephritis (8%). The age of diagnosis increased for IgA Nephropathy over time while it decreased for membranous nephritis.

CONCLUSIONS

Our study adds data for the completion of the kidney biopsy map in our region.

Links between oropharyngeal microbiota and IgA nephropathy: A paradigm shift from isolated microbe to microbiome

Immunoglobulin A nephropathy (IgAN) is the most prevalent form of primary glomerulonephritis globally, yet its pathogenesis remains incompletely understood. While much research has focused on the gut microbiome in the development of the disease, emerging evidence suggests that the oropharyngeal microbiota may also be a potential contributor. Studies have revealed significant alterations in oropharyngeal microbial diversity and specific bacterial taxa in IgAN patients, correlating with disease severity and progression. This review aims to comprehensively summarize and discuss the key findings from in vitro, in vivo, and clinical studies into the oropharyngeal bacteria and microbiome alterations in IgAN. Clinical studies have identified associations between certain oropharyngeal bacteria, particularly Cnm+Streptococcus mutans, Campylobacter rectus, and Porphyromonas gingivalis with IgAN patients and severe clinical outcomes with. In vitro and in vivo studies further establish a causal relationship between IgAN and oropharyngeal bacteria such as Streptococcus and Haemophilus. Microbiome analyses demonstrate dysbiotic patterns in IgAN patients and identify new potential bacterial genera that have yet to be explored experimentally but may potentially contribute to the disease's pathogenesis. Additionally, the use of these bacterial genera as diagnostic and prognostic biomarkers of IgAN has achieved promising performance. Overall, the evidence highlights the strong connection between oropharyngeal bacteria and IgAN through both causal and non-causal associations. Further investigation into these newly identified bacterial genera and integration of multi-omics data are necessary to uncover mechanisms, validate their role in IgAN, and potentially develop novel diagnostic and therapeutic approaches.

Development of a Diagnostic Model for Focal Segmental Glomerulosclerosis: Integrating Machine Learning on Activated Pathways and Clinical Validation

Background

Focal segmental glomerulosclerosis (FSGS) represents a major global health challenge, with its incidence rising in parallel with advances in diagnostic techniques and the growing prevalence of chronic diseases. This study seeks to enhance the diagnostic accuracy of FSGS by integrating machine learning approaches to identify activated pathways, complemented by robust clinical validation.

Methods

We analyzed data from 163 FSGS patients and 42 living donors across multiple GEO cohorts via the ComBat algorithm to address batch effects and ensure the comparability of gene expression profiles. Gene set enrichment analysis (GSEA) identified key signaling pathways involved in FSGS pathogenesis. We then developed a highly accurate diagnostic model by integrating nine machine learning algorithms into 101 combinations, achieving near-perfect AUC values across training, validation, and external cohorts. The model identified six genes as potential biomarkers for FSGS. Additionally, immune cell infiltration patterns, particularly those involving natural killer (NK) cells, were explored, revealing the complex interplay between genetics and the immune response in FSGS patients. Immunohistochemical analysis validated the expression of the key markers CD99 and OAZ2 and confirmed the association between NK cells and FSGS.

Results

The glmBoost+Ridge model exhibited exceptional diagnostic accuracy, achieving an AUC of 0.998 using just six genes: BANF1, TUSC2, SMAD3, TGFB1, CD99, and OAZ2. The prediction score was calculated as follows: score = (0.3997×BANF1) + (0.5543×TUSC2) + (0.5279×SMAD3) + (0.4118×TGFB1) + (0.8665×CD99) + (0.5996×OAZ2). Immunohistochemical analysis confirmed significantly elevated expression levels of CD99 and OAZ2 in the glomeruli and tubulointerstitial tissues of FSGS patients compared with those of controls.

Conclusion

This study demonstrates a highly accurate machine learning model for FSGS diagnosis. Immunohistochemical validation confirmed elevated expression of CD99 and OAZ2, offering valuable insights into FSGS pathogenesis and potential biomarkers for clinical application.

Epidemiology of glomerular diseases in a Colombian population

BACKGROUND

Glomerular diseases are a diverse group of conditions with variations in clinical presentation, pathophysiology, diagnosis, and treatment. Renal biopsy is essential for determining their aetiology and prognosis.

OBJECTIVE

To describe the epidemiology of glomerular diseases based on histopathological studies conducted in the Department of Pathology at the School of Medicine, University of Antioquia, Colombia, between 1988 and 2023.

MATERIALS AND METHODS

A retrospective, descriptive, cross-sectional study was conducted on patients with glomerular disease who underwent renal biopsy between 1988 and 2023. A descriptive analysis was performed on their sociodemographic, clinical, laboratory, and pharmacological characteristics.

RESULTS

A total of 4567 histopathology reports were analysed. Of these, 56.6% were from women, with an average age of 32 years. Nephrotic syndrome was the most common indication for renal biopsy (35.0%). Lupus nephritis was the most prevalent diagnosis (28.2%), followed by focal segmental glomerulosclerosis (16.6%). In adults, lupus nephritis and focal segmental glomerulosclerosis were the most frequent diagnoses, while in children, minimal change disease and focal segmental glomerulosclerosis were the most common.

CONCLUSIONS

The type of glomerular disease varies according to sociodemographic factors such as age and sex. Lupus nephritis and focal segmental glomerulosclerosis were the most common glomerular diseases. The main indications for biopsy were nephrotic syndrome and abnormal urinary sediment.

Implementation and first report of the Brazilian Kidney Biopsy Registry

BACKGROUND

Kidney biopsy registries are valuable tools for guiding clinical practice and developing health policies. In 2021, the Brazilian Society of Nephrology (SBN) created the Brazilian Kidney Biopsy Registry (BKBR). This is the first BKBR report, presenting patient data from 2021.

METHODS

BKBR is a web-based platform hosted on the BSN website, which contains patient demographics, clinical data, frequency, and distribution of histologic diagnosis of Brazilian adult native kidney biopsies.

RESULTS

Of the 1012 cases registered in 2021, 954 cases were evaluated after excluding pediatric and kidney transplant cases. Twenty-one centers enrolled patients, with representation from all Brazilian regions. There was a slight predominance of females (52.6%), a mean age of 44.7 ± 16 years, and 13.6% of patients were >65 years old. The main indication for kidney biopsy was renal dysfunction (56%) and nephrotic syndrome (41.4%), respectively. At the time of the biopsy, 47.9% of the patients were hypertensive and 15.2% were diabetic. Although 66.2% of patients had eGFR ≤60ml/min/1.73m2 upon biopsy, the majority (60.2%) had mild interstitial fibrosis and tubular atrophy. The most frequent diagnosis in the BKBR was glomerular disease (74.8%). Lupus nephritis was the most frequent diagnosis of glomerular disease (22.6%), followed by IgA nephropathy (13%) and focal segmental glomerulosclerosis (12.2%).

CONCLUSION

This is the first report of a Nationwide registry of kidney biopsies in Brazil. This data provides pivotal information about the kidney disease profile in this country with continental dimensions.

Design and baseline characteristics of the Finerenone, in addition to standard of care, on the progression of kidney disease in patients with Non-Diabetic Chronic Kidney Disease (FIND-CKD) randomized trial

BACKGROUND

Finerenone, a non-steroidal mineralocorticoid receptor antagonist, improved kidney and cardiovascular outcomes in patients with chronic kidney disease (CKD) and type 2 diabetes in two phase 3 outcome trials. The Finerenone, in addition to standard of care, on the progression of kidney disease in patients with Non-Diabetic Chronic Kidney Disease (FIND-CKD) study investigates the effect of finerenone in adults with CKD without diabetes.

METHODS

FIND-CKD (NCT05047263 and EU CT 2023-506897-11-00) is a randomized, double-blind, placebo-controlled phase 3 trial in patients with CKD of non-diabetic aetiology. Adults with a urinary albumin:creatinine ratio (UACR) ≥200-≤3500 mg/g and an estimated glomerular filtration rate (eGFR) ≥25-<90 ml/min/1.73 m2 receiving a maximum tolerated dose of a renin-angiotensin system inhibitor were randomized 1:1 to once-daily placebo or finerenone 10 or 20 mg depending on eGFR >60 or <60 ml/min/1.73 m2. The primary efficacy outcome is total eGFR slope, defined as the mean annual rate of change in eGFR from baseline to month 32. Secondary efficacy outcomes include a combined cardiorenal composite outcome comprising time to kidney failure, sustained ≥57% decrease in eGFR, hospitalization for heart failure or cardiovascular death, as well as separate kidney and cardiovascular composite outcomes. Adverse events are recorded to assess tolerability and safety.

RESULTS

Across 24 countries, 3231 patients were screened and 1584 were randomized to study treatment. The most common causes of CKD were chronic glomerulonephritis (57.0%) and hypertensive/ischaemic nephropathy (29.0%). Immunoglobulin A nephropathy was the most common glomerulonephritis (26.3% of the total population). At baseline, mean eGFR and median UACR were 46.7 ml/min/1.73 m2 and 818.9 mg/g, respectively. Diuretics were used by 282 participants (17.8%), statins by 851 (53.7%) and calcium channel blockers by 794 (50.1%). Sodium-glucose co-transporter 2 (SGLT2) inhibitors were used in 16.9% of patients; these individuals had a similar mean eGFR (45.6 versus 46.8 ml/min/1.73 m2) and a slightly higher median UACR (871.9 versus 808.3 mg/g) compared with those not using SGLT2 inhibitors at baseline.

CONCLUSIONS

FIND-CKD is the first phase 3 trial of finerenone in patients with CKD of non-diabetic aetiology.

Systematic review of the application of the Kidney Failure Risk Equation and Oxford classification in estimating prognosis in IgA Nephropathy

BACKGROUND

IgA nephropathy (IgAN) is the most common primary glomerulonephritis in the world and is an important cause of chronic kidney disease (CKD) and kidney failure. Outcomes are heterogeneous, and accurate risk stratification is important to identify the highest risk individuals for treatment and to help prevent disease progression. The Oxford classification (OC) is an internationally adopted standard for renal biopsy reporting in IgAN, which measures the degree of histological abnormalities and predicts prognosis. The kidney failure risk equation (KFRE) was developed to predict kidney failure in all causes of CKD and has been shown to be highly accurate across diverse etiologies. This review aimed to compare the KFRE with formulae incorporating the OC in accurately determining the risk of kidney failure in IgAN.

METHODS

A systematic review was conducted in accordance with the Cochrane library guidelines and PRISMA statement for reporting of systematic reviews. Studies comparing the accuracy of the KFRE with the OC in predicting disease progression and kidney failure in IgAN were evaluated. The search strategy and analysis were performed independently by two reviewers. Studies that were eligible for inclusion compared the KFRE with any tool incorporating the OC in a cohort of individuals with IgAN. Eligible outcomes were reduction of estimated glomerular filtration rate (eGFR) or end-stage renal disease (ESRD), and prognostic tools were required to assess the accuracy of these formulae by discrimination and/or calibration.

RESULTS

After searching several databases, only one study was eligible for inclusion in the review. This study of 2300 Chinese individuals with IgAN had a median follow-up of 2.5 years. Two-hundred eighty-eight individuals had a composite outcome of 50% decline in eGFR or ESRD, and 214 individuals developed ESRD. Both the KFRE and the IgAN Risk Prediction (IRP) tool (incorporating the OC) were highly accurate at predicting ESRD with a C-statistic of 0.90 and 0.91, respectively. Subgroup analysis demonstrated improved performance of IRP over KFRE in discrimination for individuals with preserved eGFR (> 60 ml/min/1.73 m2) at baseline. The risk of bias was high due to insufficient follow-up and handling of missing data, so overall confidence in findings is very low.

CONCLUSION

There is currently insufficient evidence to compare the accuracy of the KFRE and OC in determining outcomes in IgAN. Further research is required in this field.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022364569.

Epidemiology and burden of focal segmental glomerulosclerosis among United States Veterans: An analysis of Veteran's Affairs data

INTRODUCTION

Focal segmental glomerulosclerosis (FSGS) is a rare glomerular disease that can lead to reduced kidney function and kidney failure (KF). The objective of this study was to describe the epidemiology, characteristics, clinical outcomes, healthcare resource utilization, and costs associated with focal segmental glomerulosclerosis (FSGS) in United States (US) veterans.

METHODS

This retrospective cohort study included patients in the National Veterans Affairs Health Care Network with ≥2 FSGS-associated diagnostic codes that were 30-180 days apart (October 1999-February 2021). Annual FSGS incidence and prevalence per 1,000,000 US veterans were calculated. Patient and disease characteristics as of the index date (date of first FSGS diagnosis) and baseline (6-months pre-index) comorbidities were described. Kaplan-Meier analyses were used to assess overall survival and time from index to KF or death, dialysis, and kidney transplant. Post-index medication use, HRU, and direct healthcare costs were summarized.

RESULTS

The study included 2,515 veterans with FSGS who were followed for an average of 8.9 years. The mean age was 57.5 years, most patients were male (94.6%), and the most common comorbidity was hypertension (87.0%). The mean annual incidence and prevalence of FSGS during 2000-2020 were 19.6 and 164.7 per million veterans, respectively. Approximately half (51.5%) died during follow-up (median time: 11.6 years) and 76.9% had kidney failure (4.1 years). Overall, 43.3% underwent dialysis and 5.8% had a kidney transplant. During follow-up, statins and calcium channel blockers were commonly used (81.9% and 75.1%). During the first year post-index, 40% had an inpatient admission and 33% visited the emergency room; mean total healthcare cost per patient in the analysis was $36,543.

CONCLUSIONS

Among US veterans, FSGS is associated with considerable clinical and economic burdens. Better treatments for FSGS are needed to slow kidney disease progression, improve patient outcomes, and reduce the burden.

Risk factors of disease activity and renal damage in patients with systemic lupus erythematosus

PURPOSE

To evaluate the clinical features of patients with Systemic Lupus Erythematosus (SLE) and explore the risk factors of disease activity and renal damage.

METHODS

A retrospective study involving 194 patients were performed. Patients were divided into lupus nephritis (LN) group (63.40%) and non-LN group (36.60%), different disease activity group, and different renal function group according to the clinical data. Multivariate logistic regression analysis showed that albumin (ALB), uric acid (UC), total cholesterol (TC), and anti-dsDNA antibodies were the influencing factors of LN in patients with SLE (P < 0.05); ALB, UC, and complement 3(C3) were the influencing factors of lupus disease activity (P < 0.05); UC, C3, and hemoglobin (HB) were the influencing factors of abnormal renal function in SLE patients.

RESULTS

The results of the ROC curve showed that ALB, UA, and TC had certain predictive value for combined LN in patients with SLE, and the predictive value of ALB was greater than that of TC (P < 0.05); ALB, UA, and C3 being predictors of the activity of patients with SLE; BUN, UA, and HB all had certain predictive value for the abnormal renal function in patients with LN. SLE patients have the high incidence of renal impairment.

CONCLUSION

The results of this study suggest that patients with SLE should regularly monitor the levels of ALB, UA, TC, C3, and HB, as well as pay attention to the intervention of hyperlipidemia and hyperuricemia in patients with SLE to better control disease progression.

Long-term renal survival in patients with IgA nephropathy: a systematic review

The management strategy for IgA nephropathy (IgAN), has undergone constant improvements since the disease entity was first described 50 years ago. However, it is still unknown how these changes affected the long-term renal survival of IgAN patients. We systematically evaluate changes in IgAN renal survival by searching PubMed, Embase, and the Cochrane Library Database of Systematic Reviews from inception to 19 May 2024. We included a large sample of 103076 IgAN cases from 158 studies. Renal survival rates were 94.16% (95% CI: 94.02% to 94.31%), 88.68% (95% CI: 88.48% to 88.87%), and 78.13% (95% CI: 77.82% to 78.43%) at three, five, and ten-year, respectively. Over the past few decades, there haven't been any sound changes in the 3-year and 5-year renal survival rates. The kidney survival rate in developed countries is higher than in developing countries. Researchers consistently show that while proteinuria < 1.0 g/24 h, renal survival rates increase dramatically. In IgAN, long-term renal survival fluctuated rather than continuously improving over time. Our system review's findings indicate that supportive care-the most important recommendation for managing IgAN has shown promising results. The long-term outcomes of IgAN could be significantly improved by the latest developed treatment options.

Prognostic role of mesangial IgM deposition in IgA nephropathy: a long-term cohort study

BACKGROUND

The clinical significance of mesangial immunoglobulin (Ig) M deposition in IgA nephropathy (IgAN) has been less explored and remains a topic of debate. Therefore, our study aimed to investigate the prognostic value of mesangial IgM deposition in a long-term follow-up cohort of IgAN patients.

METHODS

A unicentric retrospective study was conducted on 93 consecutive IgAN patients (median age 41 years, 68% male, eGFR 48.7 mL/min, proteinuria 1.1 g/g) from 2010 to 2015. They were followed until end-stage kidney disease (ESKD), death, or until the end of the study in January 2021, with a median follow-up of 7 years. An independent pathologist evaluated the IgM immunofluorescence pattern, Oxford MEST-C score, and transmission electron microscopy (TEM) lesions following a comprehensive protocol.

RESULTS

In our cohort, 70% had mesangial IgM-positive deposits, while 30% were IgM-negative. Both groups were similar in age, sex, prevalence of arterial hypertension, Charlson comorbidity scores, kidney function (eGFR and proteinuria), pathology findings (Oxford MEST-C score, IgG and C3 immune deposition), and TEM analysis. Treatment with RASI and immunosuppression, and death rates were also comparable. However, 37% of IgM-positive patients progressed to ESKD, significantly higher than the 11% in the IgM-negative group. Univariate and multivariate Cox proportional hazards regression analyses identified lower eGFR, higher Oxford MEST-C score, and mesangial IgM deposits as independent factors associated with shorter kidney survival.

CONCLUSIONS

Our study highlights mesangial IgM deposition as a potential risk factor for ESKD in patients with advanced IgAN, laying a foundation for further research in this area.

Analysis of the Sensitivity and Specificity of Histopathological Findings for Diagnosing Lupus Nephritis

BACKGROUND

Since the introduction of the SLICC criteria in 2012, biopsy-proven lupus nephritis (LN) has been the only independent diagnostic criterion for systemic lupus erythematosus (SLE). This was reaffirmed by the EULAR/ACR in 2019, emphasizing the importance of renal biopsy in LN. However, the current classification lacks specific histopathological criteria for defining LN. This study describes the histological findings of patients with LN, compares them with those of other glomerular diseases, and evaluates their diagnostic accuracy in a large Latin American population.

METHODS

This retrospective cohort included 731 kidney biopsies from two distinct academic centers. The patients were divided into two groups as follows: a LN group and a control group comprising patients with membranous nephropathy, IgA nephropathy, membranoproliferative glomerulonephritis, pauci-immune glomerulonephritis, and proliferative glomerulonephritis. Sensitivity and specificity analyses were conducted for various histopathological features.

RESULTS

We identified the following five features strongly correlated with LN: mesangial proliferation, subendothelial deposits, C1q staining ≥1+, dominant IgG, and ≥4 positive immunofluorescence elements. Combined, these features yielded an area under the ROC curve of 0.94 (95% CI: 0.91-0.95). These results were validated in a diverse population. In membranous nephropathy, histological features such as mesangial deposits, C1q positivity, and ≥4 positive immunofluorescence elements effectively distinguished class V LN from non-lupus membranous nephropathy, with an area under the ROC curve of 0.85 (95% CI: 0.76-0.93).

CONCLUSIONS

The combination of mesangial proliferation, subendothelial deposits, C1q staining ≥1+, dominant IgG, and ≥4 positive immunofluorescence elements offer good accuracy for diagnosing renal involvement in SLE in a large Latin American population. In the absence of pathognomonic features, combined criteria are valuable diagnostic tools, particularly when other SLE criteria are lacking.

Potential Role of Mineralocorticoid Receptor Antagonists in Nondiabetic Chronic Kidney Disease and Glomerular Disease

Glomerular disease is a leading cause of CKD and ESKD. Although diabetic kidney disease is the most common cause of glomerular disease, nondiabetic causes include malignancy, systemic autoimmune conditions, drug effects, or genetic conditions. Nondiabetic glomerular diseases are rare diseases, with a paucity of high-quality clinical trials in this area. Furthermore, late referral can result in poor patient outcomes. This article reviews the current management of nondiabetic glomerular disease and explores the latest developments in drug treatment in this area. Current treatment of nondiabetic glomerular disease aims to manage complications (edema, hypertension, proteinuria, hyperlipidemia, hypercoagulability, and thrombosis) as well as target the underlying cause of glomerular disease. Treatment options include renin-angiotensin-aldosterone system inhibitors, statins/nonstatin alternatives, loop diuretics, anticoagulation agents, immunosuppressives, and lifestyle and dietary modifications. Effective treatment of nondiabetic glomerular disease is limited by heterogeneity and a lack of understanding of the disease pathogenesis. Sodium-glucose cotransporter-2 inhibitors and nonsteroidal mineralocorticoid receptor antagonists (ns-MRAs, such as finerenone), with their broad anti-inflammatory and antifibrotic effects, have emerged as valuable therapeutic options for a range of cardiorenal conditions, including CKD. ns-MRAs are an evolving drug class of particular interest for the future treatment of nondiabetic glomerular disease, and there is evidence that these agents may improve kidney prognosis in various subgroups of patients with CKD. The benefits offered by ns-MRAs may present an opportunity to reduce the progression of CKD from a spectrum of glomerular disease. Several novel ns-MRA are in clinical development for both diabetic and nondiabetic CKD.

Dual blockade of endothelin A and angiotensin II type 1 receptors with sparsentan as a novel treatment strategy to alleviate IgA nephropathy

INTRODUCTION

Although immunoglobulin A nephropathy (IgAN) had been discovered more than 50 years ago, 30-40% of IgAN patients still have primary glomerular disease that progresses to end-stage renal disease. However, various treatment strategies for IgAN have rapidly expanded in recent years to include endothelin (ET) receptor antagonists.

AREAS COVERED

In this review, we discuss the role of the ET-1/ETA receptor axis in the development of IgAN, especially focusing on the potential of sparsentan, a dual ET and angiotensin receptor antagonist as a novel therapy for IgAN.

EXPERT OPINION

Evaluation of the MEST-C score at the time of renal biopsy in IgAN is important in determining treatment strategies. If lesions are mainly in the acute phase, such as crescents, steroid therapy should be continued. However, if lesions are mainly in the chronic phase, such as glomerulosclerosis, sparsentan rather than steroid or angiotensin II receptor blocker alone may improve renal outcomes. Although further clinical studies are needed to back up these assumptions, appropriate combination of new drugs containing sparsentan and conventional drugs for IgAN treatment at the appropriate disease stage is expected to further inhibit the progression of renal damage.

Mechanistic study of celastrol-mediated inhibition of proinflammatory activation of macrophages in IgA nephropathy via down-regulating ECM1

Increasing evidence suggests that the mononuclear/macrophage system is vital in amplifying the inflammatory cascade in IgA Nephropathy (IgAN). However, the pathogenic mechanism of macrophages in IgAN and targeted treatment strategies still need to be explored. This study found that botanical triterpene celastrol (CLT) effectively alleviated renal lesions, M1-like macrophage infiltration, inflammatory factors production, and improved renal function in IgAN mice. We found that the renal macrophages of IgAN patients had high expression of ECM1, a crucial molecule involved in macrophage inflammatory polarization, positively correlated with the IgAN clinical severity. In murine macrophage Raw 264.7 cells, CLT inhibited macrophage M1-like polarization and the output of TNF-α and IL-6 by downregulating the ECM1/STAT5 pathway. Mechanistically, molecular docking, CESTA, and immunoprecipitation verified that CLT directly bound to ECM1 and increased the ubiquitination of ECM1. Collectively, these results illustrated that CLT inhibited proinflammatory macrophage in IgAN by directly targeting ECM1 to promote ubiquitination degradation of ECM1. Therefore, this study may provide a theoretical basis for exploring the pathogenesis of IgAN and identifying new perspectives for targeted therapy of IgAN.

RNA-Seq-Based Transcriptome Analysis of Chinese Cordyceps Aqueous Extracts Protective Effect against Adriamycin-Induced mpc5 Cell Injury

Pharmacogenomic analysis based on drug transcriptome characteristics is widely used to identify mechanisms of action. The purpose of this study was to elucidate the molecular mechanism of protective effect against adriamycin (ADM)-induced mpc5 cell injury of Chinese cordyceps aqueous extracts (WCCs) by a systematic transcriptomic analysis. The phytochemicals of WCCs were analyzed via the "phenol-sulfuric acid method", high-performance liquid chromatography (HPLC), and HPLC-mass spectrometry (MS). We analyzed the drug-reaction transcriptome profiles of mpc5 cell after treating them with WCCs. RNA-seq analysis revealed that WCCs alleviated ADM-induced mpc5 cell injury via restoring the expression of certain genes to normal level mainly in the one-carbon pool by the folate pathway, followed by the relaxin, apelin, PI3K-Akt, and nucleotide-binding, oligomerization domain (NOD)-like receptor signaling pathway, enhancing DNA synthesis and repair, cell proliferation, fibrosis reduction, and immune regulation. Otherwise, WCCs also modulated the proliferation and survival of the mpc5 cell by regulating metabolic pathways, and partially restores the expression of genes related to human disease pathways. These findings provide an innovative understanding of the molecular mechanism of the protective effect of WCCs on ADM-induced mpc5 cell injury at the molecular transcription level, and Mthfd2, Dhfr, Atf4, Creb5, Apln, and Serpine1, etc., may be potential novel targets for treating nephrotic syndrome.

Shen-yan-yi-hao oral solution ameliorates IgA nephropathy via intestinal IL-17/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis in the world, it is one of the most common causes of kidney disease and can lead to end-stage kidney disease, however, its pathogenesis is still complicated. The Shen-yan-yi-hao oral solution (SOLI) is an effective prescription for the clinical treatment of IgAN while its specific mechanism remains to be further elucidated.

AIM OF THE STUDY

This study investigates SOLI's effects on IgAN in rats, particularly on the intestinal mucosal barrier, and identifies potential therapeutic targets through network pharmacology and molecular docking, validated experimentally.

MATERIALS AND METHODS

Target genes for SOLI in IgAN were identified and analysed through molecular docking and KEGG pathway enrichment. An IgAN rat model examined SOLI's effect on renal biomarkers and cytokines involved in specific pathways, ileum mucosal lesions, and the intestinal immune system. The IL-17 pathway's role was studied in IEC-6 cells with SOLI in vitro.

RESULT

Rats developed increased proteinuria and kidney damage marked by IgA deposition and inflammation. SOLI treatment significantly ameliorated these symptoms, reduced galactose-deficient Ig A1 (Gd-IgA1), and decreased cytokines like IL-17, TNF-α, IL-6 and IL-1β etc. SOLI also normalized intestinal tight junction protein expression, ameliorated intestinal damage, and regulated intestinal immune response (focused on IL-17/NF-κB signal pathway). SOLI moderated the abnormally activated IL-17 pathway, which damages intestinal epithelial cells, suggesting IgAN treatment potential.

CONCLUSION

SOLI reduces proteinuria and enhances intestinal mucosal function in IgAN rats, kidney protection in the IgAN rat model may initiate from modulating the intestinal IL-17/NF-κB pathway and subsequent Gd-IgA1 accumulation.

IgA Nephropathy: Epidemiology and Disease Risk Across the World

Despite decades of research, our knowledge of the global epidemiology of IgA nephropathy remains limited. Much of what we know about IgA nephropathy incidence comes from biopsy registry studies that are subject to bias related to differences in screening programs, referral patterns, and access to healthcare. Fewer epidemiologic studies used an appropriate data infrastructure that includes a well-defined source population. Nonetheless, all these studies show considerable geographic variation in disease incidence with an increase from west to east and south to north across Eurasia. This pattern is partly explained by the distribution of genetic risk alleles in individuals of European and East Asian ancestry. Although historically thought to be an indolent disease, recent long-term follow-up studies have demonstrated an exceptionally high lifetime risk of kidney failure. The International IgA Nephropathy Prediction Tool, derived and validated in multiple ethnically diverse cohorts, has improved our ability to identify patients at high risk of progression who may benefit from therapies being tested in clinical trials. The earlier identification of high-risk patients, evaluation of novel risk factors, and accurate assessment of global disease burden require high-quality regional data infrastructures and broad collaborative efforts to ensure the impact of new treatments is maximized.

The Etiology of Advanced Chronic Kidney Disease in Southeast Asia: A Meta-analysis

INTRODUCTION

Chronic kidney disease (CKD) etiology varies greatly between developed and developing countries. In addition, differences in underlying pathogenesis and therapeutic options affect the progression towards advanced-CKD. This meta-analysis aims to identify the etiology of advanced-CKD in Southeast Asia.

METHODS

A systematic search in four electronic-databases and complementary search on national kidney registries and repository libraries was conducted until July 20, 2023. The risk of bias was assessed using Newcastle-Ottawa Scale for observational studies and Version-2 of Cochrane for intervention studies. A random-effects model was used to estimate pooled prevalence. The protocol is registered in the International Prospective Register of Systematic Reviews PROSPERO; Registration ID:CRD42022300786.

RESULTS

We analyzed 81 studies involving 32,834 subjects. The pooled prevalence of advanced-CKD etiologies are diabetic kidney disease (DKD) 29.2% (95%CI 23.88-34.78), glomerulonephritis 20.0% (95%CI 16.84-23.38), hypertension 16.8% (95%CI 14.05-19.70), other 8.6% (95%CI 6.97-10.47), unknown 7.5% (95%CI 4.32-11.50), and polycystic kidney disease 0.7% (95%CI 0.40-1.16). We found a significant increase in DKD prevalence from 21% (9.2%, 95%CI 0.00-33.01) to 30% (95%CI 24.59-35.97) before and after the year 2000. Among upper-middle-income and high-income countries, DKD is the most prevalent (26.8%, 95%CI 21.42-32.60 and 38.9%, 95%CI 29.33-48.79, respectively), while glomerulonephritis is common in lower-middle-income countries (33.8%, 95%CI 15.62-54.81).

CONCLUSION

The leading cause of advanced-CKD in Southeast Asia is DKD, with a substantial proportion of glomerulonephritis. An efficient screening program targeting high-risk populations (diabetes mellitus and glomerulonephritis) is needed, with the aim to delay CKD progression.

Nephrotic Syndrome Throughout Childhood: Diagnosing Podocytopathies From the Womb to the Dorm

The etiologies of podocyte dysfunction that lead to pediatric nephrotic syndrome (NS) are vast and vary with age at presentation. The discovery of numerous novel genetic podocytopathies and the evolution of diagnostic technologies has transformed the investigation of steroid-resistant NS while simultaneously promoting the replacement of traditional morphology-based disease classifications with a mechanistic approach. Podocytopathies associated with primary and secondary steroid-resistant NS manifest as diffuse mesangial sclerosis, minimal change disease, focal segmental glomerulosclerosis, and collapsing glomerulopathy. Molecular testing, once an ancillary option, has become a vital component of the clinical investigation and when paired with kidney biopsy findings, provides data that can optimize treatment and prognosis. This review focuses on the causes including selected monogenic defects, clinical phenotypes, histopathologic findings, and age-appropriate differential diagnoses of nephrotic syndrome in the pediatric population with an emphasis on podocytopathies.

IgAN Across the Age Spectrum: The Pediatric Perspective

IgA nephropathy (IgAN) presents with different expressions and natural histories across ages. The direct comparison of incidence and progression of IgAN in children and adults is difficult due to different policies for performing kidney biopsy in different ages and countries. In the past decade the focus has been on assessing the individual risk profile at kidney biopsy or after 1 year of follow-up in children and adults. This would help avoid overtreatment and unnecessary drug exposure in benign cases of IgAN, and promptly initiate an aggressive therapy in progressive ones. This issue is particularly relevant in children. This review addresses some recent insights into the similarities and differences of IgAN across the age spectrum, with a particular focus on the prognostic predictors of progression in children and in adults, aiming at offering some critical elements useful for treatment choices for IgAN across ages.

Post-transplant IgA Nephropathy

Immunoglobulin A (IgA) nephropathy is the most common glomerulonephritis in many countries. Most patients progress to kidney failure for which kidney transplantation is the optimal therapy. Unfortunately, IgA nephropathy commonly recurs post transplant and shortens allograft survival. Multiple recipient and donor characteristics have been associated with the risk of recurrence, although these have varied between different cohorts. The clinical expression of post-transplant IgA nephropathy is modified by immunosuppression. Biomarkers have been identified and studied in native-kidney IgA nephropathy but need validation in transplantation. Treatment of recurrent IgA nephropathy hinges on supportive measures derived largely from evidence in native-kidney IgA nephropathy. The improved understanding of the autoimmune mechanisms of disease in native-kidney IgA nephropathy has led to promising new targets for treatment, which may in turn be deployed in post-transplant IgA nephropathy.

IgA Vasculitis and IgA Nephropathy: Two Sides of the Same Coin?

IgA vasculitis (IgAV) is considered a systemic form of IgA nephropathy (IgAN). The two diseases share similar geographic and ethnic distribution, along with common variants in genetic association studies. The pathophysiology of IgAN and IgA vasculitis nephritis (IgAVN) can be explained by the four-hit hypothesis. Key molecules involved at each step in both diseases were evaluated as diagnostic and prognostic biomarkers with many common factors, most prominently serum galactose-deficient IgA1. On kidney biopsy, the two diseases are indistinguishable, and the established histological Oxford classification for IgAN will soon be validated for IgAVN. Chronic lesions (segmental glomerulosclerosis and tubular atrophy / interstitial fibrosis) seem more frequent in IgAN, while proliferative lesions (endocapillary hypercellularity and crescents) are more frequent in IgAVN, which could explain the worse IgAN renal prognosis. Due to characteristic skin rash, IgAVN patients are diagnosed precociously. Conversely, the frequent absence of overt clinical signs in IgAN leads to a delayed diagnostic kidney biopsy in the disease evolution, which explains the chronic pathologic lesions. From a therapeutic perspective, while impressive advances have been made in recent years for IgAN, there is a glaring lack of evidence-based guidelines for the treatment of IgAVN. Large therapeutic clinical studies are required, and future IgAN trials should include IgAVN.

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.

Are children with IgA nephropathy different from adult patients?

BACKGROUND

Previously, several studies have indicated that pediatric IgA nephropathy (IgAN) might be different from adult IgAN, and treatment strategies might be also different between pediatric IgAN and adult IgAN.

METHODS

We analyzed two prospective cohorts established by pediatric and adult nephrologists, respectively. A comprehensive analysis was performed investigating the difference in clinical and pathological characteristics, treatment, and prognosis between children and adults with IgAN.

RESULTS

A total of 1015 children and 1911 adults with IgAN were eligible for analysis. More frequent gross hematuria (88% vs. 20%, p < 0.0001) and higher proteinuria (1.8 vs. 1.3 g/d, p < 0.0001) were seen in children compared to adults. In comparison, the estimated glomerular filtration rate (eGFR) was lower in adults (80.4 vs. 163 ml/min/1.73 m2, p < 0.0001). Hypertension was more prevalent in adult patients. Pathologically, a higher proportion of M1 was revealed (62% vs. 39%, p < 0.0001) in children than in adults. S1 (62% vs. 28%, p < 0.0001) and T1-2 (34% vs. 8%, p < 0.0001) were more frequent in adults. Adjusted by proteinuria, eGFR, and hypertension, children were more likely to be treated with glucocorticoids than adults (87% vs. 45%, p < 0.0001). After propensity score matching, in IgAN with proteinuria > 1 g/d, children treated with steroids were 1.87 (95% CI 1.16-3.02, p = 0.01) times more likely to reach complete remission of proteinuria compared with adults treated with steroids.

CONCLUSIONS

Children present significantly differently from adults with IgAN in clinical and pathological manifestations and disease progression. Steroid response might be better in children.

Role of serum complement C3 and C4 on kidney outcomes in IgA nephropathy

IgA Nephropathy (IgAN) is the most prevalent glomerular disease worldwide. Complement system activation is crucial in its pathogenesis. Few studies correlated serum C3 and C4 with disease activity and prognosis. This retrospective study investigated the prognostic value of serum complement at the time of diagnosis in patients with IgAN. Specifically we evaluated whether adding serum C3 and C4 levels to established predictive models-one based on variables related to chronic kidney disease (CKD) progression and another incorporating variables from the International IgA Prediction Tool (IntIgAPT)-enhances the accuracy of outcome prediction. A composite renal outcome was defined as 50% decline in eGFR or onset of kidney failure. 101 patients were stratified according to baseline C3 levels in three groups (Low, Medium and High). During a median follow-up of 54 months, the Low group exhibited higher incidence of primary outcome (16.3 events vs 2.9 and 1.7 events × 100 pts/year, p = 0.0026). Model-1 (M1), consisting of CKD progression variables, and Model-3 (M3), comprising IntIgANPT variables, were implemented with baseline C3 and C4 to create Model-2 (M2) and Model-4 (M4), respectively. M2 demonstrated better predictive performance over M1, showing higher discrimination (lower AIC and BIC, higher C-index and NR2). Similarly, M4 outperformed M3, showing enhanced outcome prediction when C3 and C4 levels were added. Implementation of serum C3 and C4 can enhance prediction accuracy of already-validated prognostic models in IgAN. Lower C3 and higher C4 levels were associated with poorer prognosis, highlighting a more 'Complement-Pathic' subset of patients.

Hidden genetics behind glomerular scars: an opportunity to understand the heterogeneity of focal segmental glomerulosclerosis?

Focal segmental glomerulosclerosis (FSGS) is a complex disease which describes different kinds of kidney defects, not exclusively linked with podocyte defects. Since nephrin mutation was first described in association with early-onset nephrotic syndrome (NS), many advancements have been made in understanding genetic patterns associated with FSGS. New genetic causes of FSGS have been discovered, displaying unexpected genotypes, and recognizing possible site of damage. Many recent large-scale sequencing analyses on patients affected by idiopathic chronic kidney disease (CKD), kidney failure (KF) of unknown origin, or classified as FSGS, have revealed collagen alpha IV genes, as one of the most frequent sites of pathogenic mutations. Also, recent interest in complex and systemic lysosomal storage diseases, such as Fabry disease, has highlighted GLA mutations as possible causes of FSGS. Tubulointerstitial disease, recently classified by KDIGO based on genetic subtypes, when associated with UMOD variants, may phenotypically gain FSGS features, as well as ciliopathy genes or others, otherwise leading to completely different phenotypes, but found carrying pathogenic variants with associated FSGS phenotype. Thus, glomerulosclerosis may conceal different heterogeneous conditions. When a kidney biopsy is performed, the principal objective is to provide an accurate diagnosis. The broad spectrum of phenotypic expression and genetic complexity is demonstrating that a combined path of management needs to be applied. Genetic investigation should not be reserved only to selected cases, but rather part of medical management, integrating with clinical and renal pathology records. FSGS heterogeneity should be interpreted as an interesting opportunity to discover new pathways of CKD, requiring prompt genotype-phenotype correlation. In this review, we aim to highlight how FSGS represents a peculiar kidney condition, demanding multidisciplinary management, and in which genetic analysis may solve some otherwise unrevealed idiopathic cases. Unfortunately there is not a uniform correlation between specific mutations and FSGS morphological classes, as the same variants may be identified in familial cases or sporadic FSGS/NS or manifest a variable spectrum of the same disease. These non-specific features make diagnosis challenging. The complexity of FSGS genotypes requires new directions. Old morphological classification does not provide much information about the responsible cause of disease and misdiagnoses may expose patients to immunosuppressive therapy side effects, mistaken genetic counseling, and misguided kidney transplant programs.

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.

Rationale and design of the Japanese Biomarkers in Nephrotic Syndrome (J-MARINE) study

INTRODUCTION

Disease subtyping and monitoring are essential for the management of nephrotic syndrome (NS). Although various biomarkers for NS have been reported, their clinical efficacy has not been comprehensively validated in adult Japanese patients.

METHODS

The Japanese Biomarkers in Nephrotic Syndrome (J-MARINE) study is a nationwide, multicenter, and prospective cohort study in Japan, enrolling adult (≥18 years) patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), membranoproliferative glomerulonephritis (MPGN), C3 glomerulopathy (C3G), and lupus nephritis (LN). Baseline clinical information and plasma and urine samples will be collected at the time of immunosuppressive therapy initiation or biopsy. Follow-up data and plasma and urine samples will be collected longitudinally based on the designated protocols. Candidate biomarkers will be measured: CD80, cytotoxic T-lymphocyte antigen 4, and soluble urokinase plasminogen activator receptor for MCD and FSGS; anti-phospholipase A2 receptor and thrombospondin type-1 domain-containing protein 7A antibodies for MN; fragment Ba, C3a, factor I, and properdin for MPGN/C3G; and CD11b, CD16b, and CD163 for LN. Outcomes include complete and partial remission, relapse of proteinuria, a 30% reduction in estimated glomerular filtration rate (eGFR), eGFR decline, and initiation of renal replacement therapy. The diagnostic accuracy and predictive ability for clinical outcomes will be assessed for each biomarker.

RESULTS

From April 2019 to April 2023, 365 patients were enrolled: 145, 21, 138, 10, and 51 cases of MCD, FSGS, MN, MPGN/C3G, and LN, respectively.

CONCLUSION

This study will provide valuable insights into biomarkers for NS and serve as a biorepository for future studies.

Epidemiological, immunological, and treatment response profile of patients with lupus nephritis in Brazil

BACKGROUND AND HYPOTHESIS

Brazil has the largest number of individuals of African descent outside Africa and a very admixed population. Among cases of lupus nephritis (LN) in the country, there are differences in incidence, and even in severity, depending on the location and characteristics of the population studied. The aim of this study was to describe the clinical and epidemiological characteristics of LN in Brazil, as well as to determine which of those characteristics would be risk factors for a poor renal prognosis.

METHODS

This was a retrospective, descriptive observational study of patients diagnosed with LN who underwent kidney biopsy between 1999 and 2015 in the Nephrology Department of the Hospital das Clínicas, in São Paulo, Brazil. Data were collected from electronic medical records.

RESULTS

We evaluated 398 patients, among who 94.1% and 77.7% tested positive for antinuclear antibodies and anti-DNA antibodies, respectively, whereas 33.7% showed the full-house pattern. The time from LN symptom onset to biopsy was <6 months in 47.5% (early biopsy group) and ≥6 months in 52.5% (late biopsy group). In the early biopsy group, the chronicity index was lower and the activity index was higher. Multivariate analysis showed that a higher chronicity index was the only independent risk factor for progression to requiring kidney replacement therapy.

CONCLUSION

Late biopsy seems to be associated with negative renal outcomes in LN. However, it seems that a higher chronicity index is the main predictor of a poor renal outcome among patients with LN in Brazil.

C3 Hypocomplementemia Predicts the Progression of CKD towards End-Stage Kidney Disease in IgA Nephropathy, Irrespective of Histological Evidence of Thrombotic Microangiopathy

Background: IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. IgAN causes end-stage kidney disease (ESKD) in 30-40% of all cases. The activation of the complement system by pathological circulating IgAs, which is often associated with low serum C3 levels (LowC3), seems to play a crucial role. Previous studies have shown an association between histological evidence of TMA, which is the result of alternative complement activation, and poor outcomes. However, it is not known to what extent the decrease in serum C3 levels reflects ongoing TMA injury. Our study aimed at assessing the association between LowC3 and ESKD and whether this association reflects ongoing TMA. Methods: We enrolled all patients with biopsy-proven IgAN and followed-up patients until their last visit, ESKD, or death. Results: Of the 56 patients included in the study, 12 (21%) presented low serum C3 (LowC3) at the time of renal biopsy. TMA was significantly more frequent in the LowC3 group [7/12 (58%) vs. 9/44 (20%), p = 0.02]. After adjusting for potential confounders, LowC3 was strongly associated with an increased hazard of ESKD (hazard ratio [HR]: 5.84 [95%CI: 1.69, 20.15; p = 0.005). The association was not affected by adjusting for TMA. The estimated overall proportion of the relation between C3 and ESKD mediated by TMA was low and not statistically significant. Conclusions: Our study provides evidence that C3 hypocomplementemia is associated with an increased risk of ESKD through mechanisms that are largely independent from TMA.

Focal Segmental Glomerulosclerosis Patient Baseline Characteristics in the Sparsentan Phase 3 DUPLEX Study

Introduction

The phase 3 DUPLEX trial is evaluating sparsentan, a novel, nonimmunosuppressive, single-molecule dual endothelin angiotensin receptor antagonist, in patients with focal segmental glomerulosclerosis (FSGS).

Methods

DUPLEX (NCT03493685) is a global, multicenter, randomized, double-blind, parallel-group, active-controlled study evaluating the efficacy and safety of sparsentan 800 mg once daily versus irbesartan 300 mg once daily in patients aged 8 to 75 years (USA/UK) and 18 to 75 years (ex-USA/UK) weighing ≥20 kg with biopsy-proven FSGS or documented genetic mutation in a podocyte protein associated with FSGS, and urine protein-to-creatinine ratio (UP/C) ≥1.5 g/g. Baseline characteristics blinded to treatment allocation are reported descriptively.

Results

The primary analysis population includes 371 patients (336 adult, 35 pediatric [<18 years]) who were randomized and received study drug (median age, 42 years). Patients were White (73.0%), Asian (13.2%), Black/African American (6.7%), or Other race (7.0%); and from North America (38.8%), Europe (36.1%), South America (12.7%), or Asia Pacific (12.4%). Baseline median UP/C was 3.0 g/g; 42.6% in nephrotic-range (UP/C >3.5 g/g [adults]; >2.0 g/g [pediatrics]). Patients were evenly distributed across estimated glomerular filtration rate (eGFR) categories corresponding to chronic kidney disease (CKD) stages 1 to 3b. Thirty-three patients (9.4% of 352 evaluable samples) had pathogenic or likely pathogenic (P/LP) variants of genes essential to podocyte structural integrity and function, 27 (7.7%) had P/LP collagen gene (COL4A3/4/5) variants, and 14 (4.0%) had high-risk APOL1 genotypes.

Conclusions

Patient enrollment in DUPLEX, the largest interventional study in FSGS to date, will enable important characterization of the treatment effect of sparsentan in a geographically broad and clinically diverse FSGS population.

Clinical and histopathological characteristics of primary focal segmental glomerulosclerosis in Turkish adults

The data regarding primary FSGS (pFSGS) from different parts of the world differ. While the prevalence of pFSGS has been increasing in Western countries like the USA, it follows an inconsistent trend in Europe and Asia and a decreasing trend in Far Eastern countries such as China in the last two decades. There are undetermined factors to explain those national and geographic discrepancies. Herein, we aimed to reveal the current prevalence with clinical and histopathological characteristics of pFSGS in Turkish adults. This study includes the biopsy-proven pFSGS patients data recorded between 2009 and 2019, obtained from the national multicenter primary glomerulonephritis registry system of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) database. 850 of the 3875 primer glomerulonephritis patients(21.9%) have pFSGS. The mean age is 40.5 ± 14.2 and 435 (51.2%) of patients are male. Nephrotic syndrome is the most common biopsy indication (59.2%). 32.6% of patients have hematuria, 15.2% have leukocyturia and 7.8% have both. Serum creatinine, albumin, and proteinuria are 1.0 mg/dL (IQR = 0.7-1.4) mg/dl, 3.4 ± 0.9 g/dl, 3400 mg/day(IQR, 1774-5740), respectively. Females have lower mean arterial pressure (- 2.2 mmHg), higher eGFR (+ 10.0 mL/min/1.73 m2), and BMI (+ 1.6 kg/m2) than males. Thickened basal membrane(76.6%) and mesangial proliferation (53.5%) on light microscopy are the major findings after segmental sclerosis. IgM (32.7%) and C3 (32.9%) depositions are the most common findings on immunofluorescence microscopy. IgM positivity is related to lower eGFR, serum albumin, and higher proteinuria. The prevalence of pFSGS is stable although slightly increasing in Turkish adults. The characteristics of the patients are similar to those seen in Western countries.

The CXCR4-AT1 axis plays a vital role in glomerular injury via mediating the crosstalk between podocyte and mesangial cell

Glomeruli stand at the center of nephrons to accomplish filtration and albumin interception. Podocytes and mesangial cells are the major constituents in the glomeruli. However, their interdependency in glomerular injury has rarely been reported. Herein, we investigated the role of C-X-C chemokine receptor type 4 (CXCR4) in mediating the crosstalk between podocytes and mesangial cells. We found CXCR4 and angiotensin II (AngII) increased primarily in injured podocytes. However, type-1 receptor of angiotensin II (AT1) and stromal cell-derived factor 1α (SDF-1α), a ligand of CXCR4, were evidently upregulated in mesangial cells following the progression of podocyte injury. Ectopic expression of CXCR4 in 5/6 nephrectomy mice increased the decline of renal function and glomerular injury, accelerated podocyte injury and mesangial cell activation, and initiated CXCR4-AT1 axis signals. Additionally, treatment with losartan, an AT1 blocker, interrupted the cycle of podocyte injury and mesangial matrix deposition triggered by CXCR4. Podocyte-specific ablation of CXCR4 gene blocked podocyte injury and mesangial cell activation. In vitro, CXCR4 overexpression induced oxidative stress and renin angiotensin system (RAS) activation in podocytes, and triggered the communication between podocytes and mesangial cells. In cultured mesangial cells, AngII treatment induced the expression of SDF-1α, which was secreted into the supernatant to further promote oxidative stress and cell injury in podocytes. Collectively, these results demonstrate that the CXCR4-AT1 axis plays a vital role in glomerular injury via mediating pathologic crosstalk between podocytes and mesangial cells. Our findings uncover a novel pathogenic mechanism by which the CXCR4-AT1 axis promotes glomerular injury.

The Impact of Obesity on Kidney Disease: Observational Cohort Study Analyzing 14,492 Kidney Biopsy Cases

BACKGROUND

The obesity epidemic is associated with the emergence of new kidney diseases including obesity-related glomerulopathy (ORG) and metabolic syndrome-associated disorders. However, the effects of obesity on prevalence and outcome of biopsy-proven kidney disease are not well known.

METHODS

We analyzed 14,492 kidney biopsies in 18 hospitals from 1979 to 2018 in Korea. Obesity was defined as a body mass index value of ≥ 30 kg/m².

RESULTS

The most common disease was IgA nephropathy (IgAN) in both obese and non-obese participants (33.7% vs. 38.9%). Obesity was associated with a higher risk of focal segmental glomerulosclerosis (FSGS) and hypertensive nephropathy (HT-N) (odds ratio [OR], 1.72, 95% confidence interval [CI], 1.37-2.17; OR, 1.96, 95% CI, 1.21-3.19) and a lower risk of IgAN (OR, 0.74, 95% CI, 0.62-0.88). During the median follow up of 93.1 ± 88.7 months, obesity increased the risk of end-stage kidney disease (ESKD) in patients with IgAN (relative risk [RR], 1.49, 95% CI, 1.01-2.20) and lupus nephritis (LN) (RR, 3.43, 95% CI, 1.36-8.67). Of 947 obese individuals, ORG was detected in 298 (31.5%), and 230 participants had other kidney diseases, most commonly, IgAN (40.9%) followed by diabetic nephropathy (15.2%). Participants with ORG, when combined with other renal diseases, showed higher risks for developing ESKD compared to those with ORG alone (RR, 2.48, 95% CI, 1.09-5.64).

CONCLUSION

Obesity is associated with an increased risk of FSGS and HT-N, and also increase the ESKD risk in IgAN and LN patients. ORG in obese participants may have favorable renal outcomes if it occurs alone without any other renal disease.

Treatment of IgA Nephropathy: A Rapidly Evolving Field

The pivotal event in the pathophysiology of IgA nephropathy is the binding of circulating IgA-containing immune complexes to mesangial cells, with secondary glomerular and tubulointerstitial inflammation and fibrosis. The paramount difficulty in the management of IgA nephropathy is the heterogeneity in its clinical presentation and prognosis, requiring an individualized treatment approach. Goal-directed supportive care remains the bedrock of therapy for all patients, regardless of risk of progression. Sodium-glucose transporter 2 inhibitors and sparsentan should be integral to contemporary supportive care, particularly in patients with chronic kidney damage. Pending the development of reliable biomarkers, it remains a challenge to identify patients prone to progression due to active disease and most likely to derive a net benefit from immunosuppression. The use of clinical parameters, including the degree of proteinuria, the presence of persistent microscopic hematuria, and the rate of eGFR loss, combined with the mesangial hypercellularity, endocapillary hypercellularity, segmental glomerulosclerosis, tubular atrophy/interstitial fibrosis, crescents score, is currently the best approach. Systemic glucocorticoids are indicated in high-risk patients, but the beneficial effects wane after withdrawal and come at the price of substantial treatment-associated toxicity. Therapies with direct effect on disease pathogenesis are increasingly becoming available. While targeted-release budesonide has garnered the most attention, anti-B-cell strategies and selective complement inhibition will most likely prove their added value. We propose a comprehensive approach that tackles the different targets in the pathophysiology of IgA nephropathy according to their relevance in the individual patient.

Differences in the epidemiology, management and outcomes of kidney disease in men and women

Improved understanding of differences in kidney disease epidemiology, management and outcomes in men and women could help nephrologists to better meet the needs of their patients from a sex- and gender-specific perspective. Evidence of sex differences in the risk and outcomes of acute kidney injury is mixed and dependent on aetiology. Women have a higher prevalence of chronic kidney disease (CKD) stages 3-5 than men, whereas men have a higher prevalence of albuminuria and hence CKD stages 1-2. Men show a faster decline in kidney function, progress more frequently to kidney failure and have higher mortality and risk of cardiovascular disease than women. However, the protective effect of female sex is reduced with CKD progression. Women are less likely than men to be aware of, screened for and diagnosed with CKD, started on antiproteinuric medication and referred to nephrologist care. They also consistently report a poorer health-related quality of life and a higher symptom burden than men. Women experience greater barriers than men to access the waiting list for kidney transplantation, particularly with respect to older age and obesity. However, women also have longer survival than men after transplantation, which may partly explain the comparable prevalence of transplantation between the sexes.

The impact of SARS-CoV-2 infection on renal function in patients with biopsy-proven kidney diseases

BACKGROUND

We sought to evaluate the long-term effects of COVID-19 on renal function in patients with biopsy-proven kidney diseases.

METHODS

A total of 451 patients with biopsy-proven kidney disease and at least 12 months of follow-up subsequent to COVID-19 pandemic onset were included in the study. The primary study endpoint was a composite of a persistent decline of more than 30% in eGFR or ESRD.

RESULTS

23.1% of patients had COVID-19 during a follow-up period of 2.5 y (0.8-2.6), while 17.6% of patients reached the composite endpoint. Those with COVID-19 were more likely to reach the composite endpoint [26.7% vs. 14.8%; OR, 2.1 (95%CI, 1.23-3.58), p = 0.006). There was a significant eGFR change in the first year of follow-up between the two study groups [-2.24 (95%CI,-4.86; 0.37) vs. +2.31 (95%CI, 0.78; 3.85) ml/min, p = 0.004], with an adjusted mean difference of -4.68 ml/min (95%CI,-7.7; -1.59)(p = 0.03). The trend for worse renal outcomes remained consistent in patients with IgAN, MN and FSGS, but not in those with LN. After multivariate adjustment, the independent predictors of the composite endpoint were baseline eGFR (HR, 0.94; 95%CI, 0.92-0.95), COVID-19 (HR, 1.91; 1.16-3.12) and male gender (HR, 1.64; 95%CI, 1.01-2.66). In multivariate linear regression analysis, COVID-19 independently determined a reduction of eGFR at 12 months by 4.62 ml/min/1.73m2 (β coefficient, -4.62; 95%CI, -7.74 to -1.5, p = 0.004).

CONCLUSIONS

There is a significant impact of COVID-19 on long-term renal function in patients with biopsy-proven kidney diseases, leading to a greater decline of eGFR and a worse renal survival.

Changes in spectrum of biopsy-proven kidney diseases within decade: an analysis based on 10 199 cases from South China

PURPOSE

To assess the regional epidemiological trends of kidney diseases over time in the South China using renal biopsy-proven cases.

METHODS

This retrospective observational cohort study was conducted at the Institute of Nephrology, Second Xiangya Hospital of Central South University, and encompasses all patients diagnosed with kidney disease via biopsy from 2012 to 2021.

RESULTS

The study sample consisted of 10 199 native kidneys, with a male-to-female ratio of 0.91:1 and an average age of 38.74 (±14.53) years. Primary glomerular nephropathy, systemic glomerular nephropathy (SGN), tubulointerstitial disease, and hereditary renal diseases accounted for 66.92 (6825)%, 24.49 (2498)%, 8.06 (822)%, and 0.53 (54)%, respectively. The leading pathologies of primary glomerular nephropathy remained the IgA nephropathy. The frequencies of IgA nephropathy and membranous nephropathy increased significantly, whereas the frequencies of minimal change disease and focal segmental glomerulosclerosis decreased (P < .001) between 2017 and 2021 than in the years 2012 and 2016. An earlier onset of membranous nephropathy was observed in the age group of 45-59 years compared to previous studies. The leading pathologies of SGN were found to be lupus nephritis (758 cases, 30.45%) and hypertension nephropathy (527 cases, 21.17%). The frequencies of hypertension nephropathy and diabetic nephropathy increased between 2017 and 2021 compared to 2012 and 2016 (P < .001), gradually becoming the leading pathological types of SGN. In elderly patients diagnosed with nephrotic syndrome, the frequencies of amyloidosis significantly increased (P < .01).

CONCLUSION

Our study may provide insights for kidney disease prevention and public health strategies. What is already known on this topic The pathological spectrum of kidney diseases has undergone significant transformations in the past decade, driven by the escalating incidence of chronic diseases. Although there are studies exploring the renal biopsy findings from various regions in China which present both similarities and differences in epidemiology, few large-scale reports from the South China in recent decades were published. What this study adds Our findings reveal the following key observations: (i) increased proportion of middle-aged patients leading to the increasing average age at the time of biopsy；(ii) the frequencies of IgA nephropathy and membranous nephropathy (MN) increased significantly, whereas the frequencies of minimal change disease and focal segmental glomerulosclerosis decreased (P < .001) between 2017 and 2021 than in the years 2012 and 2016; (iii) earlier onset of MN in the age group of 45-59 years old was found in our study; and (iv) a higher frequency of hypertension nephropathy and DN presented over time, and frequency of amyloidosis increased in elderly patients diagnosed with NS. How this study might affect research, practice, or policy This single-center yet a large-scale study of the kidney disease spectrum in South China may provide a reference point for the diagnosis, treatment, and prevention of chronic kidney disease.

Ethnicity and IgA nephropathy: worldwide differences in epidemiology, timing of diagnosis, clinical manifestations, management and prognosis

Immunoglobulin A nephropathy (IgAN), the most common primary glomerulonephritis, is one of the major causes of end-stage renal disease. Significant variances in epidemiology, clinical manifestation, timing of diagnosis, management and renal prognosis of IgAN have been reported worldwide. The incidence of IgAN is the most frequent in Asia, followed by Europe, and lower in Africa. Moreover, Asian patients show more frequent acute lesions in renal histology and present poorer renal outcomes compared with Caucasians. The comorbidities also show the difference between Asians and Caucasians. Although the frequency of gross hematuria with upper respiratory tract infection is not different, comorbidities with gastrointestinal diseases are reported to be higher in Europe. Recently, genetic studies for variant ethnic patients revealed widely ranging genetic risks in each ethnicity. A genetic risk score is most elevated in Asians, intermediate in Europeans and lowest in Africans, consistent with the disease prevalence of IgAN globally. Ethnic variance might be highly affected by the difference in genetic background. However, it is also essential to mention that the different timing of diagnosis due to variant urinary screening systems and the indication for renal biopsy in different countries may also contribute to these variances. The management of IgAN also varies internationally. Currently, several novel therapies based on the pathogenesis of IgAN are being assessed and are expected to become available soon. Further understanding the ethnic variance of IgAN might help establish individualized care for this disease. Here, we review the issues of ethnic heterogeneities of IgAN.

Global trends and hotspots in IgA nephropathy: a bibliometric analysis and knowledge map visualization from 2012 to 2023

OBJECTIVES

This study aimed to investigate the distribution patterns and research frontiers of international literature and thus present a holistic bibliometric evaluation of the studies on IgA nephropathy.

METHODS

The Web of Science Core Collection database was searched for studies of IgA nephropathy from January 2012 to March 2023. The keywords and references are analyzed by CiteSpace, while the countries and institutions are analyzed by VOSviewer.

RESULTS

A total of 2987 publications on IgA nephropathy were included. The country with the most publications was China (n = 1299), and the institution with the most publications was Peking University (n = 139). The most frequent keywords were IgA nephropathy (n = 2013), Oxford classification (n = 482), and diseases (n = 433). The keywords that continue to burst out at high intensity are multicenter study and gut microbiota. Moreover, the top five references for burst strength were also listed.

CONCLUSIONS

IgA nephropathy has attracted widespread research interest, particularly in high-prevalence areas. From 2012 to 2023, publications on IgA nephropathy show a linear increase. China is the country with the highest number of publications and Peking University is the institution with the highest number of publications. Current research hotspots and frontiers are mainly multicenter studies related to IgA nephropathy and its exploration with gut microbiota. Overall, we have provided a comprehensive scientometric analysis of IgA nephropathy that will inform researchers and healthcare practitioners.

Long-term follow-up of an IgA nephropathy cohort: outcomes and risk factors

AIM

IgA nephropathy (IgAN), the most common glomerulopathy worldwide and in Uruguay, raised treatment controversies. The study aimed to analyze long-term IgAN outcomes and treatment.

METHODS

A retrospective analysis of a Uruguayan IgAN cohort, enrolled between 1985 and 2009 and followed up until 2020, was performed. The Ethics Committee approved the study. The inclusion criteria were (a) biopsy-proven IgAN; (b) age ≥12 years; and (c) available clinical, histologic, and treatment data. The patients were divided into two groups, with immunosuppressive (IS) or without (NoIS) treatment. Outcomes (end-stage kidney disease/kidney replacement therapy [ESKD/KRT] or all-cause death) were obtained from mandatory national registries.

RESULTS

The study population included 241 patients (64.7% men), median age 32 (19.5) years, baseline blood pressure <130/80 mmHg in 37%, and microhematuria in 67.5% of patients. Baseline proteinuria, glomerulosclerosis, and a higher crescent percentage were significantly more frequent in the IS group. Proteinuria improved in both groups. Renal survival at 20 years was 74.6% without difference between groups. In the overall population and in the NoIS group, bivariate Cox regression analysis showed that baseline proteinuria, endocapillary hypercellularity, tubule interstitial damage, and crescents were associated with a higher risk of ESKD/KRT or death, but in the IS group, proteinuria and endocapillary hypercellularity were not. In the multivariate Cox analysis, proteinuria in the NoIS group, crescents in the IS group and tubule interstitial damage in both groups were independent risk factors.

CONCLUSION

The IS group had more severe risk factors than the NoIS group but attained a similar outcome.