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Objective: The objective of this study is to investigate the diagnostic utility of microRNAs (miRNAs) for distinguishing between urine samples from patients with Diabetic Kidney Disease (DKD) and those with Focal Segmental Glomerulosclerosis (FSGS)., Methods: In this multicentric, cross-sectional investigation, we enrolled patients diagnosed with DKD, individuals with primary biopsy-proven FSGS, and healthy controls. The top 5 miRNAs (hsa-mir-21, hsa-mir-30a, hsa-mir-193a, hsa-mir-196a, hsa-mir-200a) were selected to quantify miRNAs in urine samples. Isolation of targeted miRNAs was performed from urinary exosomes, and the quantitative profile of the isolated miRNAs was measured by RT-qPCR. The ΔΔCt method was implemented to calculate the fold differences between disease and control samples., Results: Thirteen DKD patients, 11 FSGS patients, and 14 healthy controls were included in this study. Hsa-mir-21 and hsa-mir-30a exhibited distinct regulation in both groups, with upregulation observed in FSGS and downregulation in DKD (hsa-mir-21 in DKD (0.668 ± 0.25, p < 0.0005) and FSGS (2.267 ± 1.138, p < 0.0077); hsa-mir-30a in DKD (0.874 ± 0.254, p = 0.079) and FSGS (1.378 ± 0.312, p < 0.0006)). Hsa-mir-193a exhibited significant dysregulation in DKD (1.017 ± 0.413, p < 0.029) but not in FSGS (4.18 ± 1.528, p = 0.058). Hsa-mir-196a and hsa-mir-200a showed upregulation in patient groups (hsa-mir-196a in DKD (1.278 ± 0.527, p = 0.074) and FSGS (2.47 ± 0.911, p < 0.0003); hsa-mir-200a in DKD (1.909 ± 0.825, p = 0.082) and FSGS (1.301 ± 0.358, p < 0.008))., Conclusion: Specific miRNAs, particularly miR-21, miR-30a, miR-196a, and miR-200a, might play a role in the pathogenesis of kidney diseases and could potentially serve as biomarkers to distinguish between FSGS and DKD patients., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Trabulus et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Podocytopathies, including minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), and collapsing glomerulopathy (CG), are kidney diseases that damage glomerular podocytes, leading to heavy proteinuria and nephrotic syndrome (NS). Inflammation plays a critical role in the progression of chronic kidney disease (CKD), with recent studies linking inflammatory biomarkers to declining kidney function. Tumor necrosis factor-alpha (TNF-α), an essential inflammatory cytokine, interacts with its circulating receptors, TNFR1 and TNFR2. The TNF-α pathway has been implicated in the pathogenesis of FSGS and MCD. Increased circulating TNFR2 levels have been associated with worsening renal function in podocytopathies, suggesting that the TNF-α inflammatory pathway significantly contributes to disease progression., Methods: We conducted a study involving 53 patients with biopsy-proven MCD or FSGS and 53 healthy, age- and gender-matched controls. All patients were followed for 18 months. We analyzed serum and urine TNFR2 levels and gene expression at baseline and after three months. To assess the ability of TNFR2 to predict persistent decline in estimated glomerular filtration rate (eGFR < 30 mL/min/1.73m 2 ), remission, and relapse, we employed Cox regression analysis. Additionally, we evaluated its prognostic utility for predicting progression to stage 4 CKD using ROC curve analysis., Results: Serum and urine TNFR2 levels were significantly elevated in patients compared to controls. Serum TNFR2 was a significant predictor in univariate Cox regression analysis for persistent eGFR decline (HR 1.017, 95% CI: 1.003 to 1.032, p = 0.018), remission (HR 0.995, 95% CI: 0.992 to 0.999, p = 0.006), and relapse (HR 1.005, 95% CI: 1.001 to 1.010, p = 0.029). The ROC curve analysis demonstrated that serum TNFR2 levels had a strong prognostic ability for predicting progression to stage 4 CKD, with an AUC of 0.848 (95% CI: 0.737-0.960), sensitivity of 81%, and specificity of 71%., Conclusion: This study underscores the critical role of circulating TNFR2 in kidney injury among patients with primary podocytopathy. Elevated TNFR2 levels are significant predictors of persistent eGFR decline and disease relapse, highlighting their potential as biomarkers for disease progression and prognosis., (© 2024. The Author(s).)

Proteinuria selectivity index (PSI) is a potential tool for histological classification and prediction of treatment response in nephrotic syndrome, but evidence is insufficient. Clinical relevance of fractional excretion of sodium (FENa) in nephrotic syndrome remains largely unexplored. This multicenter retrospective study included patients with nephrotic syndrome who underwent kidney biopsy between January 2012 and June 2022. Optimal cutoffs for predicting complete remission based on PSI and FENa were determined using receiver operating characteristic curves. Patients were divided into two groups using these cutoffs and followed until complete remission. Of the 611 patients included, 177 had minimal change disease (MCD), 52 had focal segmental glomerulosclerosis (FSGS), and 149 had membranous nephropathy (MN). Median (interquartile range) PSI were 0.14 (0.09-0.19) for MCD, 0.33 (0.23-0.40) for FSGS, and 0.20 (0.14-0.30) for MN. FENa were 0.24 (0.09-0.68), 1.03 (0.50-2.14), and 0.78 (0.41-1.28). Patients with low PSI and FENa had a higher incidence of complete remission. Cox regression analyses demonstrated that both parameters were associated with achieving complete remission (HR 2.73 [95% CI 1.97-3.81] and HR 1.93 [95% CI 1.46-2.55], respectively). PSI and FENa may be useful for histological classification and predicting remission in nephrotic syndrome., (© 2024. The Author(s).)

Background: Sparsentan has shown positive effects on managing different subtypes of glomerulonephritis. The recent results of trials require a pooled analysis to validate these results., Aim: We aim to assess the safety and efficacy of sparsentan versus irbesartan for patients with IgA nephropathy and focal glomerulosclerosis (FSGS)., Methods: We conducted a systematic review and meta-analysis of randomized controlled trials retrieved by systematically searching PubMed, Web of Science, Scopus, and Cochrane through March 2024. We used Review Manager v.5.4 to pool dichotomous data using risk ratio (RR) and continuous data using mean difference (MD) with a 95% confidence interval (CI)., Results: Three studies with a total of 884 patients were included. Sparsentan was superior to irbesartan in improving urine protein to creatinine ratio (UP/C) (ratio of percentage reduction 0.66, 95% CI [0.58 to 0.74], P < 0.001); as well as the proportion of patients achieved complete and partial remission of proteinuria (RR = 2.57, 95% CI [1.73 to 3.81], P < 0.001) and (RR = 1.63, 95% CI [1.4 to 1.91], P < 0.001) respectively. Regarding the effect on the glomerular filtration rate, the results estimate did not favor either sparsentan or irbesartan (MD = 1.98 ml/min per 1.73mm2, 95% CI [-1.05 to 5.01], P = 0.2). There were no significant differences in adverse events except for hypotension, which showed higher rates in the sparsentan group (RR = 2.02, 95% CI [1.3 to 3.16], P = 0.002)., Conclusion: Sparsentan is effective and has a good safety profile for treating FSGS and patients with IgA nephropathy. However, more well-designed RCTs against ARBs, ACE inhibitors, and steroids with larger sample sizes are needed to get conclusive evidence., (© 2024. The Author(s).)

Background: Immunoglobulin A (IgA) vasculitis nephritis (IgAVN) is the most common secondary IgA nephropathy (IgAN). Urinary C4d have been identified associated with the development and progression in primary IgAN; however, its role in kidney disease progression of IgAVN is still unclear., Methods: This study enrolled 139 patients with IgAVN, 18 healthy subjects, 23 focal segmental glomerulosclerosis patients and 38 IgAN patients. Urinary C4d levels at kidney biopsy were measured using enzyme-linked immunosorbent assay. The association between urinary C4d/creatinine and kidney disease progression event, defined as 40% estimated glomerular filtration rate decline or end-stage kidney disease, was assessed using Cox proportional hazards models and restricted cubic splines., Results: The levels of urinary C4d/creatinine (Cr) in IgAVN and IgAN patients were higher than in healthy controls. Higher levels of urinary C4d/Cr were associated with higher proteinuria and severe Oxford C lesions, and glomerular C4d deposition. After a median follow-up of 52.79 months, 18 (12.95%) participants reached composite kidney disease progression event. The risk of kidney disease progression event was higher with higher levels of Ln(urinary C4d/Cr). After adjustment for clinical data, higher levels of urinary C4d/Cr were associated with kidney disease progression in IgAVN [per Ln-transformed urinary C4d/Cr, hazard ratio 1.573, 95% confidence interval (CI) 1.101-2.245; P = .013]. Compared with the lower C4d/Cr group, the hazard ratio was 5.539 (95% CI 1.135-27.035; P = .034) for the higher levels group., Conclusions: Higher levels of urinary C4d/Cr were associated with kidney disease progression event in patients with IgAVN., (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)

Rationale & Objective: Glomerular disorders have a highly variable clinical course, and biomarkers that reflect the molecular mechanisms underlying their progression are needed. Based on our previous work identifying plasminogen as a direct cause of podocyte injury, we designed this study to test the association between urine plasmin(ogen) (ie, plasmin and its precursor plasminogen) and end-stage kidney disease (ESKD)., Study Design: Multicenter cohort study., Setting & Participants: 1,010 patients enrolled in the CureGN Cohort with biopsy-proven glomerular disease (focal segmental glomerulosclerosis, membranous nephropathy, and immunoglobulin A nephropathy)., Predictors: The main predictor was urine plasmin(ogen) at baseline. Levels were measured by an electrochemiluminescent immunoassay developed de novo. Traditional clinical and analytical characteristics were used for adjustment. The ratio of urine plasmin(ogen)/expected plasmin(ogen) was evaluated as a predictor in a separate model., Outcome: Progression to ESKD., Analytical Approach: Cox regression was used to examine the association between urinary plasmin(ogen) and time to ESKD. Urinary markers were log 2 transformed to approximate normal distribution and normalized to urinary creatinine (Log 2 uPlasminogen/cr, Log 2 urinary protein/cr [UPCR]). Expected plasmin(ogen) was calculated by multiple linear regression., Results: Adjusted Log 2 uPlasminogen/cr was significantly associated with ESKD (HR per doubling Log 2 uPlasminogen/cr 1.31 [95% CI, 1.22-1.40], P<0.001). Comparison of the predictive performance of the models including Log 2 uPlasminogen/cr, Log 2 UPCR, or both markers showed the plasmin(ogen) model superiority. The ratio of measured/expected urine plasmin(ogen) was independently associated with ESKD: HR, 0.41 (95% CI, 0.22-0.77) if ratio<0.8 and HR 2.42 (95% CI, 1.54-3.78) if ratio>1.1 (compared with ratio between 0.8 and 1.1)., Limitations: Single plasmin(ogen) determination does not allow for the study of changes over time. The use of a cohort of mostly white patients and the restriction to patients with 3 glomerular disorders limits the external validity of our analysis., Conclusions: Urinary plasmin(ogen) and the ratio of measured/expected plasmin(ogen) are independently associated with ESKD in a cohort of patients with glomerular disease. Taken together with our previous experimental findings, urinary plasmin(ogen) could be a useful biomarker in prognostic decision making and a target for the development of novel therapies in patients with proteinuria and glomerular disease., Plain-Language Summary: Glomerular diseases are an important cause of morbidity and mortality in patients of all ages. Knowing the individual risk of progression to dialysis or transplantation would help to plan the follow-up and treatment of these patients. Our work studies the usefulness of urinary plasminogen as a marker of progression in this context, since previous studies indicate that plasminogen may be involved in the mechanisms responsible for the progression of these disorders. Our work in a sample of 1,010 patients with glomerular disease demonstrates that urinary plasminogen (as well as the ratio of measured to expected plasminogen) is associated with the risk of progression to end-stage kidney disease. Urine plasminogen exhibited good performance and, if further validated, could enable risk stratification for timely interventions in patients with proteinuria and glomerular disease., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

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., (© 2024. The Author(s), under exclusive licence to Japanese Society of Nephrology.)

Background: Hematuria is frequently present in podocytopathies, but its significance and prognostic value is not well described in these proteinuric kidney diseases. This study describes the prevalence and association between hematuria and kidney-related outcomes in these disorders., Methods: Hematuria was assessed at the initial urinalysis in participants with the following podocytopathies-membranous nephropathy, minimal change disease, and FSGS-in the Nephrotic Syndrome Study Network and Cure Glomerulonephropathy cohorts with >24 months of follow-up. Multivariable Cox proportional hazards models were fit for time to composite outcome (kidney failure or 40% decline in eGFR and eGFR <60 ml/min per 1.73 m 2 ) and proteinuria remission (urine protein-to-creatinine ratio [UPCR] <0.3 mg/mg)., Results: Among the 1516 adults and children in the study, 528 participants (35%) had FSGS, 499 (33%) had minimal change disease, and 489 (32%) had membranous nephropathy. Median (interquartile range) time from biopsy until the initial study urinalysis was 260 (49-750) days, and 498 participants (33%) were positive for hematuria. Participants with hematuria compared with those without were older (37 [16-55] versus 33 [12-55] years), more likely to have an underlying diagnosis of membranous nephropathy (44% versus 27%), had shorter time since biopsy (139 [27-477] versus 325 [89-878] days), and had higher UPCR (3.8 [1.4-8.0] versus 0.9 [0.1-3.1] g/g). After adjusting for diagnosis, age, sex, UPCR, eGFR, time since biopsy, and study cohort, hematuria was associated with a higher risk of reaching the composite outcome (hazard ratio, 1.31; 95% confidence interval, 1.04 to 1.65; P value, 0.02) and lower rate of reaching proteinuria remission (hazard ratio, 0.80; 95% confidence interval, 0.65 to 0.98; P value, 0.03)., Conclusions: Hematuria is prevalent among participants with the three podocytopathies and is significantly and independently associated with worse kidney-related outcomes, including both progressive loss of kidney function and remission of proteinuria., (Copyright © 2023 by the American Society of Nephrology.)

Background: Imerslund-Gräsbeck Syndrome (IGS) is mainly caused by CUBN gene biallelic mutations. Proteinuria accompanies IGS specific symptoms in about half of the patients, isolated proteinuria is rarely reported. Here we present 3 patients with isolated proteinuria and focal segmental glomerulosclerosis (FSGS) caused by CUBN gene biallelic pathogenic variants., Method: Whole exome sequencing was performed on three children with isolated proteinuria. CUBN gene biallelic pathogenic variants were found and then verified by sanger sequencing. Their clinical, pathological and molecular genetic characteristics were analyzed and correlated accordingly., Results: All three children presented with isolated proteinuria, no megaloblastic anemia. Their urine levels of β2 microglobulin were normal or slightly higher. Renal biopsies showed focal segmental glomerulosclerosis with mild glomerular mesangial hypercellularity, partial effacement of foot processes and podocyte microvillation. Two of them were found to carry compound heterozygous mutations and one homozygous mutation of CUBN gene. Totally four CUBN gene biallelic pathogenic variants were identified, including c.9287 T > C (p.L3096P), c.122 + 1G > A, c.7906C > T (p.R2636*), c.10233G > A (p.W3411*). Except for intron splice-site mutation, all other variants are located in highly conserved sites of CUB domain for binding to albumin., Conclusion: The results demonstrate that CUBN gene mutations may cause isolated proteinuria pathologically presented as FSGS. Our cases extend the spectrum of renal manifestation and genotype of CUBN gene mutations., (© 2022. The Author(s).)

Background: Primary focal segmental glomerulosclerosis (FSGS) frequently recurs after kidney transplantation and is associated with poor graft survival. To date, few studies have investigated predictive factors for treatment responses in recurrent FSGS., Methods: We retrospectively analyzed 16 patients who were < 16 years at the age of onset and had post-transplant recurrence of FSGS from 1993 to 2018. Patients who achieved complete remission or partial remission after initiating therapy for recurrent FSGS were defined as responders. We compared several clinical characteristics between responders and non-responders. Time to remission was also analyzed., Results: Ten patients were responders, and six patients were non-responders. Univariate analysis showed that responders had a significantly lower amount of maximum proteinuria at the time of recurrence (P = 0.015) and more highly selective proteinuria (P = 0.013) than non-responders. The time to remission from initiation of therapy was 2 months (interquartile range 0.2-4.4). In all responders, except for one patient, remission was achieved within 6 months., Conclusions: Therapeutic responses may be predicted by examining the amount and selectivity of proteinuria at the time of recurrence. Further studies with larger numbers of patients are clearly required to validate these findings.

Rationale & Objective: Remission of proteinuria has been shown to be associated with lower rates of kidney disease progression among people with focal segmental glomerulosclerosis (FSGS). The goal of this study was to evaluate whether reductions in proteinuria after treatment are associated with greater kidney survival., Study Design: Cohort analysis of clinical trial participants., Setting & Participants: Patients with steroid-resistant FSGS enrolled in a randomized treatment trial that compared cyclosporine with mycophenolate mofetil plus dexamethasone., Predictors: Reduction in proteinuria measured during 26 weeks after initiating treatment., Outcomes: Repeated assessments of estimated glomerular filtration rate (eGFR) and time to a composite outcome of kidney failure or death assessed between 26 weeks and 54 months after randomization., Analytical Approach: Multivariable linear mixed-effects models with participant-specific slope and intercept to estimate the association of change in proteinuria over 26 weeks while receiving treatment with the subsequent slope of change in eGFR. Multivariable time-varying Cox proportional hazards models were used to estimate the association of changes in proteinuria with time to the composite outcome., Results: 138 of 192 trial participants were included. Changes in proteinuria over 26 weeks were significantly related to eGFR slope. A 1-unit reduction in log-transformed urinary protein-creatinine ratio was associated with a 3.90mL/min/1.73m 2 per year increase in eGFR (95% CI, 2.01-5.79). This difference remained significant after adjusting for complete remission. There was an analogous relationship between time-varying proteinuria and time to the composite outcome: the HR per 1-unit reduction in log-transformed urinary protein-creatinine ratio was 0.23 (95% CI, 0.12-0.44)., Limitations: Limited to individuals with steroid-resistant FSGS followed up for a maximum of 5 years., Conclusions: These findings provide evidence for the benefit of urinary protein reduction in FSGS. Reductions in proteinuria warrant further evaluation as a potential surrogate for preservation of kidney function that may inform the design of future clinical trials., (Copyright © 2020 National Kidney Foundation, Inc. All rights reserved.)

Background: Urinary CD80 has emerged as potential biomarker in idiopathic nephrotic syndrome (INS). However, its cellular source remains controversial. The aim of the study was to assess whether CD80 is truly expressed by glomerular cells in INS patients during relapse and in the LPS mouse model of podocyte injury., Methods: The presence of CD80 in glomeruli was evaluated by combining immunostaining, immunogold labeling, and in situ hybridization techniques., Results: CD80 was present along the surface of glomerular endothelial cells (GEC) and rarely in podocytes in six of nine minimal change disease (MCD) patients in relapse, two of eleven patients with focal segmental glomerulosclerosis in relapse, and absent in controls. In mice, CD80 was upregulated at mRNA and protein level in GEC and podocytes, in a similar pattern to that seen in MCD patients., Conclusions: Glomerular endothelial cells and podocytes can express CD80 in patients with MCD during relapse. A better understanding of the role of CD80 in glomerular cells may provide further insights into the mechanisms of proteinuria in INS.

Background: Dent disease type 1 (DD1) is a rare X-linked disorder caused mainly by CLCN5 mutations. Patients may present with nephrotic-range proteinuria leading to erroneous diagnosis of focal segmental glomerulosclerosis (FSGS) and unnecessary immunosuppressive treatments., Methods: The following cohorts were screened for CLCN5 mutations: Chronic Kidney Disease in Children (CKiD; n = 112); Multicenter FSGS-Clinical Trial (FSGS-CT) (n = 96), and Novel Therapies for Resistant FSGS Trial (FONT) (n = 30). Urinary α 1 -microglobulin (α 1 M), albumin (A), total protein (TP), and creatinine (Cr) were assessed from CKiD subjects (n = 104); DD1 patients (n = 14); and DD1 carriers (DC; n = 8). TP/Cr, α 1 M/Cr, α 1 M/TP, and A/TP from the CKiD cohort were compared with DD1 and DC., Results: No CLCN5 mutations were detected. TP/Cr was lower in DC and CKiD with tubulointerstitial disease than in DD1 and CKiD with glomerular disease (p < 0.002). α 1 M/Cr was higher in DD1 than in CKiD and DC (p < 0.001). A/TP was lower in DD1, DC, and CKiD with tubulointerstitial disease and higher in CKiD with glomerular disease (p < 0.001). Thresholds for A/TP of ≤ 0.21 and α 1 M/Cr of ≥ 120 mg/g (> 13.6 mg/mmol) creatinine were good screens for Dent disease., Conclusions: CLCN5 mutations were not seen in screened CKiD/FSGS cohorts. In our study, a cutoff of TP/Cr > 600 mg/g (> 68 mg/mmol) and A/TP of < 0.3 had a high sensitivity and specificity to distinguish DD1 from both CKiD glomerular and tubulointerstitial cohorts. α 1 M/Cr ≥ 120 mg/g (> 13.6 mg/mmol) had the highest sensitivity and specificity when differentiating DD1 and studied CKiD populations.

Podocytes are specialized cells with a limited capacity for cell division that do not regenerate in response to injury and loss. Insults that compromise the integrity of podocytes promote proteinuria and progressive renal disease. The aim of this study was to evaluate the potential renoprotective and regenerative effects of mesenchymal stromal cells (mSC) in a severe form of the podocyte injury model induced by intraperitoneal administration of puromycin, aggravated by unilateral nephrectomy. Bone derived mSC were isolated and characterized according to flow cytometry analyses and to their capacity to differentiate into mesenchymal lineages. Wistar rats were divided into three groups: Control, PAN, and PAN+ mSC, consisting of PAN rats treated with 2 × 10 5 mSC. PAN rats developed heavy proteinuria, hypertension, glomerulosclerosis and significant effacement of the foot process. After 60 days, PAN rats treated with mSC presented a significant amelioration of all these abnormalities. In addition, mSC treatment recovered WT1 expression, improved nephrin, podocin, synaptopodin, podocalyxin, and VEGF expression, and downregulated proinflammatory Th1 cytokines in the kidney with a shift towards regulatory Th2 cytokines. In conclusion, mSC administration induced protection of podocytes in this experimental PAN model, providing new perspectives for the treatment of renal diseases associated with podocyte damage.

Focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) have similar initial histological findings; however, their prognoses are distinct. Therefore, it is of great importance to discriminate FSGS from MCD in the early phase of disease and predict clinical prognosis. A discovery set of 184 urine samples (61 healthy control, 80 MCD, and 43 FSGS) and a validation set of 61 urine samples (12 healthy control, 26 MCD, and 23 FSGS) were collected at the time of kidney biopsy. Metabolic profiles were examined using nuclear magnetic resonance spectroscopy. Of 70 urinary metabolites, myo-inositol was significantly higher in FSGS patients than in control patients (discovery set, 2.34-fold, P < 0.001; validation set, 2.35-fold, P = 0.008) and MCD patients (discovery set, 2.48-fold, P = 0.002; validation set, 1.69-fold, P = 0.042). Myo-inositol showed an inverse relationship with the initial estimated glomerular filtration rate (eGFR) and was associated with the plasma level of soluble urokinase-type plasminogen activator receptor in FSGS patients. Myo-inositol treatment ameliorated the decreased expression of ZO-1 and synaptopodin in an in vitro FSGS model, and as myo-inositol increased, myo-inositol oxygenase tissue expression decreased proportionally to eGFR. Furthermore, urinary myo-inositol exhibited an increase in the power to discriminate FSGS patients, and its addition could better predict the response to initial treatment. In conclusion, urinary myo-inositol may be an important indicator in the diagnosis and treatment of FSGS patients.

The NPHS2 gene, encoding the slit diaphragm protein podocin, accounts for genetic and sporadic forms of nephrotic syndrome (NS). Patients with NS often present symptoms of volume retention, such as oedema formation or hypertension. The primary dysregulation in sodium handling involves an inappropriate activation of the epithelial sodium channel, ENaC. Plasma proteases in a proteinuria-dependent fashion have been made responsible; however, referring to the timeline of symptoms occurring and underlying mechanisms, contradictory results have been published. Characterizing the mouse model of podocyte inactivation of NPHS2 (Nphs2 ∆pod ) with respect to volume handling and proteinuria revealed that sodium retention, hypertension and gross proteinuria appeared sequentially in a chronological order. Detailed analysis of Nphs2 ∆pod during early sodium retention, revealed increased expression of full-length ENaC subunits and αENaC cleavage product with concomitant increase in ENaC activity as tested by amiloride application, and augmented collecting duct Na + /K + -ATPase expression. Urinary proteolytic activity was increased and several proteases were identified by mass spectrometry including cathepsin B, which was found to process αENaC. Renal expression levels of precursor and active cathepsin B were increased and could be localized to glomeruli and intercalated cells. Inhibition of cathepsin B prevented hypertension. With the appearance of gross proteinuria, plasmin occurs in the urine and additional cleavage of γENaC is encountered. In conclusion, characterizing the volume handling of Nphs2 ∆pod revealed early sodium retention occurring independent to aberrantly filtered plasma proteases. As an underlying mechanism cathepsin B induced αENaC processing leading to augmented channel activity and hypertension was identified., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Recognizing patients at early phases of chronic kidney disease (CKD) is difficult, and it is even more challenging to predict acute kidney injury (AKI) and its transition to CKD. The gold standard to timely identify renal fibrosis is the kidney biopsy, an invasive procedure not usually performed for this purpose in clinical practice. SerpinA3 was identified by high-resolution-mass-spectrometry in urines from animals with CKD. An early and progressive elevation of urinary SerpinA3 (uSerpinA3) was observed during the AKI to CKD transition together with SerpinA3 relocation from the cytoplasm to the apical tubular membrane in the rat kidney. uSerpinA3/alpha-1-antichymotrypsin was significantly increased in patients with CKD secondary to focal and segmental glomerulosclerosis (FSGS), ANCA associated vasculitis (AAV) and proliferative class III and IV lupus nephritis (LN). uSerpinA3 levels were independently and positively associated with renal fibrosis. In patients with class V LN, uSerpinA3 levels were not different from healthy volunteers. uSerpinA3 was not found in patients with systemic inflammatory diseases without renal dysfunction. Our observations suggest that uSerpinA3 can detect renal fibrosis and inflammation, with a particular potential for the early detection of AKI to CKD transition and for the differentiation among lupus nephritis classes III/IV and V.

Objective: To investigate the utility of a sensitive platform using electrochemiluminescence (ECL) for the identification of low-abundance urinary protein biomarkers in lupus nephritis (LN)., Methods: Forty-eight urine samples were obtained from subjects in 2 independent cohorts, each consisting of 3 groups (matched for age, sex, and race) of 8 patients with active LN (renal Systemic Lupus Erythematosus Disease Activity Index [SLEDAI] >0), 8 patients with inactive SLE (renal SLEDAI 0), and 8 healthy controls. Samples were tested using a preexisting 40-plex ECL panel. A custom 5-plex ECL panel was then developed for further validation studies and used to test 140 urine samples (from 44 patients with active LN, 41 patients with inactive SLE, 28 healthy controls, and 27 patients with other kidney diseases)., Results: Levels of 17 urinary proteins were elevated (P < 0.05 by 2-tailed Mann-Whitney U test) in samples from patients with active LN compared to samples from patients with inactive SLE and healthy controls in cohort 1, while 9 were similarly elevated in cohort 2. Of these, interleukin-7 (IL-7), IL-12p40, IL-15, interferon-γ-inducible protein 10 (IP-10), and thymus and activation-regulated chemokine (TARC) were chosen for further validation. These 5 proteins were undetectable by enzyme-linked immunosorbent assay (ELISA). Hence, a custom 5-plex ECL panel was developed and used to validate the results from the initial 40-plex screening panel. Urinary IL-7, IL-12p40, IL-15, IP-10, and TARC levels were again significantly elevated in patients with active LN compared to those with inactive SLE and healthy controls, and correlated well with the renal SLEDAI and physician's global assessment of disease activity (R > 0.67, P < 0.05). All 5 urinary proteins were more frequently elevated in LN compared to controls with other chronic kidney diseases, although overall group differences attained significance only for urinary IL-7 and IL-15., Conclusion: Urinary levels of IL-7, IL-12p40, IL-15, IP-10, and TARC are potentially useful diagnostic tools in LN. The use of ECL assays may allow detection of urinary biomarkers that are below ELISA detection limits., (© 2019, American College of Rheumatology.)

Chronic tubulointerstitial injury impacts the prognosis of focal segmental glomerulosclerosis (FSGS). We found that the level of versican V1 was increased in tubular cells of FSGS patients. Tubular cell-derived versican V1 induced proliferation and collagen synthesis by activating the CD44/Smad3 pathway in fibroblasts. Both urine C3a and suPAR were increased and bound to the tubular cells in FSGS patients. C3a promoted the transcription of versican by activating the AKT/β-catenin pathway. C3aR knockout decreased the expression of versican in Adriamycin-treated (ADR-treated) mice. On the other hand, suPAR bound to integrin β6 and activated Rac1, which bound to SRp40 at the 5' end of exon 7 in versican pre-mRNA. This binding inhibited the 3'-end splicing of intron 6 and the base-pair interactions between intron 6 and intron 8, leading to the formation of versican V1. Cotreatment with ADR and suPAR specifically increased the level of versican V1 in tubulointerstitial tissues and caused more obvious interstitial fibrosis in mice than treatment with only ADR. Altogether, our results show that C3a and suPAR drive versican V1 expression in tubular cells by promoting transcription and splicing, respectively, and the increases in tubular cell-derived versican V1 induce interstitial fibrosis by activating fibroblasts in FSGS.

Recurrence of idiopathic focal segmental glomerulosclerosis (FSGS) is a serious complication after kidney transplantation. FSGS relapse is suspected by a sudden increase in proteinuria but there is not an accurate noninvasive diagnostic tool to confirm this entity or to detect patients at risk. We aimed to validate the diagnostic performance of ApoA-Ib to detect FSGS relapses by measuring urinary ApoA-Ib in a retrospective cohort of 61 kidney transplanted patients (37 FSGS and 24 non-FSGS). In addition, to assess the ApoA-Ib predictive ability, ApoA-Ib was measured periodically in a prospective cohort of 13 idiopathic FSGS patients who were followed during 1 year after transplantation. ApoA-Ib had a sensitivity of 93.3% and a specificity of 90.9% to diagnose FSGS relapses, with a high negative predictive value (95.2%), confirming our previous results. In the prospective cohort, ApoA-Ib predated the recurrence in four of five episodes observed. In the nonrelapsing group (n = 9), ApoA-Ib was negative in 37 of 38 samples. ApoA-Ib has the potential to be a good diagnostic biomarker of FSGS relapses, providing a confident criterion to exclude false positives even in the presence of high proteinuria. It has also the potential to detect patients at risk of relapse, even before transplantation., (© 2018 Steunstichting ESOT.)

Objectives: To detect Cytotoxic T- Lymphocyte Antigen-4 (CTLA4) single nucleotide polymorphisms (SNPs) at +49A/G (rs231775) and -318C/T (rs5742909) positions in children with idiopathic nephrotic syndrome (INS) and also assay urinary soluble CTLA4 (sCTLA4) levels in children with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS) and steroid sensitive nephrotic syndrome (SSNS) in remission., Methods: The study included 59 patients of INS (MCD-23, FSGS-15 and SSNS in remission-21) and 35 healthy controls. The CTLA4 SNPs profiling was done in peripheral blood mononuclear cells and urinary sCTLA4 level was assayed by ELISA kit., Results: Although frequency of homozygous +49 GG (rs4553808) genotype (26.3% vs. 11.4%; p = 0.231) and G allele (52.6% vs. 40%; p = 0.216) were found to be higher in INS as compared to controls, the differences were statistically non-significant. Genotypes GG, AG, AA and alleles A and G frequencies were comparable among MCD, FSGS and controls. SNP at -318 C/T (rs5742909) did not show homozygous TT genotype both in INS as well as controls. Median urinary sCTLA4/creatinine level was significantly higher in MCD as compared to FSGS (p = 0.027), SSNS in remission (p = 0.001) and controls (p = 0.003)., Conclusions: The positive associations of +49 GG genotype and G allele in patients with nephrotic syndrome were not observed. The frequencies did not differ significantly among MCD, FSGS and controls. Urinary sCTLA4 level was significantly increased in MCD; suggesting its possible role in the pathogenesis of disease.

Background: Treatment of steroid resistant nephrotic syndrome is still a challenge for physicians. There are a growing number of studies exploring genetic background of steroid-resistant glomerulopathies., Case Diagnosis/treatment: We present the case of a 4-year-old girl with steroid-resistant glomerulopathy due to a COQ6 defect with no additional systemic symptoms. The disease did not respond for second-line therapy with calcineurin inhibitor, but it remitted completely after oral treatment with 30 mg/kg/d of coenzyme Q10 (CoQ10). The patient was identified to be a compound heterozygote for two pathogenic variants in COQ6 gene: a known missense substitution c.1078C > T (p.R360W) and a novel frameshift c.804delC mutation. After 12 months of CoQ10 therapy, the child remains in full remission, her physical development accelerated, frequent respiratory airways diseases subsided., Conclusions: Genetic assessment of children with steroid-resistant nephrotic proteinuria enables therapy optimization. Proteinuria caused by a COQ6 gene defect can be successfully treated with CoQ10.

CD80, which regulates T cell activation, may provide a differential diagnostic marker between minimal change disease (MCD) and other renal diseases, including focal segmental glomerular sclerosis (FSGS). However, recent reports show contrasting results. Therefore, we evaluated the utility of urinary CD80 as a diagnostic biomarker. We collected 65 urine samples from 55 patients with MCD (n = 31), FSGS (n = 4), inherited nephrotic syndrome (n = 4), Alport syndrome (n = 5) and other glomerular diseases (n = 11), and control samples (n = 30). We measured urinary CD80 levels by ELISA. Urinary CD80 (ng/gCr) (median, interquartile range) levels were significantly higher in patients with MCD in relapse (91.5, 31.1-356.0), FSGS (376.2, 62.7-1916.0), and inherited nephrotic syndrome (220.1, 62.9-865.3), than in patients with MCD in remission (29.5, 21.7-52.8) (p < 0.05). Elevation of urinary CD80 was observed, even in patients with inherited nephrotic syndrome unrelated to T cell activation. Additionally, urinary CD80 was positively correlated with urinary protein levels. Our results suggest that urinary CD80 is unreliable as a differential diagnostic marker between MCD in relapse and FSGS or inherited kidney diseases. Increased urinary CD80 excretion was present in all patients with active kidney disease.

Objective: In this research, we explored the molecular mechanism of proteinuria in glomerulosclerosis rats and the protective effects of ATRA., Methods: This research set up three groups: SHO group, GS group, and ATRA group (15 mg/(kg d), Sigma, St. Louis, MO). The serum creatinine (Scr), urea nitrogen (BUN), and 24-h proteinuria were detected 12 weeks after administration of ATRA. The pathological and ultrastructure changes were observed under light microscope and transmission electron microscope. The protein expression of TGF-β 1 and Col-IV in glomerulus was detected by immunohitochemistry method. The mRNA and the protein expression of glomerular TRPC6 were detected by RT-PCR and Western blot., Results: In the rat model of GS, the expressions of TRPC6 were significantly elevated compared with the normal rat group; however, the use of ATRA down-regulated the expression of TRPC6 in the glomeruli and attenuated glomerulosclerosis and proteinuria. Scr and BUN were also improved by the treatment of ATRA., Conclusions: Our results demonstrated that ATRA could ameliorate glomerulosclerosis and proteinuria in GS, which may be related to suppressed expression of TRPC6.

Background: We evaluated and compared the effects of sparsentan, a dual endothelin type A (ET A ) and angiotensin II type 1 receptor antagonist, with those of the angiotensin II type 1 receptor antagonist irbesartan in patients with primary FSGS., Methods: In this phase 2, randomized, double-blind, active-control Efficacy and Safety of Sparsentan (RE-021), a Dual Endothelin Receptor and Angiotensin Receptor Blocker, in Patients with Focal Segmental Glomerulosclerosis (FSGS): A Randomized, Double-blind, Active-Control, Dose-Escalation Study (DUET), patients aged 8-75 years with biopsy-proven FSGS, eGFR>30 ml/min per 1.73 m 2 , and urinary protein-to-creatinine ratio (UP/C) ≥1.0 g/g received sparsentan (200, 400, or 800 mg/d) or irbesartan (300 mg/d) for 8 weeks, followed by open-label sparsentan only. End points at week 8 were reduction from baseline in UP/C (primary) and proportion of patients achieving FSGS partial remission end point (FPRE) (UP/C: ≤1.5 g/g and >40% reduction [secondary])., Results: Of 109 patients randomized, 96 received study drugs and had baseline and week 8 UP/C measurements. Sparsentan-treated patients had greater reductions in UP/C than irbesartan-treated patients did when all doses (45% versus 19%; P =0.006) or the 400 and 800 mg doses (47% versus 19%; P =0.01) were pooled for analysis. The FSGS partial remission end point was achieved in 28% of sparsentan-treated and 9% of irbesartan-treated patients ( P =0.04). After 8 weeks of treatment, BP was reduced with sparsentan but not irbesartan, and eGFR was stable with both treatments. Overall, the incidence of adverse events was similar between groups. Hypotension and edema were more common among sparsentan-treated patients but did not result in study withdrawals., Conclusions: Patients with FSGS achieved significantly greater reductions in proteinuria after 8 weeks of sparsentan versus irbesartan. Sparsentan was safe and well tolerated., (Copyright © 2018 by the American Society of Nephrology.)

Background: Paraneoplastic glomerulonephritis is rare in haematological malignancies and tends to manifest as minimal change disease, membranous glomerulonephritis or membranoproliferative glomerulonephritis. We present the first report of immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in a patient with asymptomatic low grade B-cell lymphoma., Case Presentation: A 53 year old gentleman presented with nephrotic range proteinuria (urine protein creatinine ratio of 662 mg/mmol) on a background of type 2 diabetes mellitus (glycosylated haemoglobin: < 6%), hypertension, obesity (body mass index: 47.6 kg/m 2 ) and degenerative spine disease. Bone marrow biopsy diagnosed a low grade B-cell lymphoma and renal biopsy was consistent with immunoglobulin A nephropathy. Lymphoma treatment with six cycles of cyclophosphamide/ rituximab/ prednisolone led to normalisation of urinary protein excretion (urine protein creatinine ratio: 14 mg/mmol at 26 months post-chemotherapy)., Conclusion: Paraneoplastic immunoglobulin A nephropathy can occur with a broad range of haematological malignancies regardless of stage. This case illustrates the importance of meticulous haematological system work-up for patients presenting with immunoglobulin A nephropathy. Recognition of paraneoplastic immunoglobulin A nephropathy and early diagnosis of associated malignancy can be life-saving.

Recent studies have indicated that urinary sediment miRNAs not only are able to serve as non-invasive diagnostic biomarkers for IgA nephropathy (IgAN) but may also be closely related to several clinical and pathological indicators. However, the lack of a suitable internal reference miRNA has hampered research into urinary sediment miRNAs. To date, U6 has been used as a reference gene in urinary sediment miRNA studies mostly based on the results from studies using tissue samples and cell lines. In a total of 330 IgAN patients, 164 disease control patients and 130 normal control patients, there was no significant difference in U6 levels. We also compared the U6 levels in different types of primary glomerular disease groups (IgA nephropathy, membranous nephropathy, minimal change nephrosis and focal segmental glomerular sclerosis). The results confirmed that there was no significant difference in the expression of U6 in different primary glomerular disease groups. Moreover, treatment had no significant effect on the expression levels of U6 in IgA nephropathy. Therefore, U6 is an excellent housekeeping gene for urinary sediment miRNA studies of IgA nephropathy.

Background: The level of urinary cluster of differentiation 80 (uCD80) is elevated in most children with minimal change disease (MCD) as opposed to focal segmental glomerulosclerosis (FSGS) during the acute phase. The objective of this follow-up study was to evaluate whether uCD80 elevation is actually associated with MCD and whether it signals better prognosis., Methods: We evaluated uCD80 levels and a series of putative progression factors in a cohort of 64 patients with nephrotic syndrome (NS) seen between 2011 and 2016. We monitored progression of chronic kidney disease (CKD), assessed as a glomerular filtration rate of < 90 ml/min/1.73 m 2 for at least 3 months. Patients were classified according to uCD80 level and to the progression rate as calculated by Kaplan-Meier survival analysis and Cox's regression analysis., Results: During a mean follow-up period of 4.8 ± 0.6 (range 3.5-6.0) years, 13 children (20%) evolved to at least CKD stage 2. The 64 patients with NS and normal baseline renal function were divided into two groups based on uCD80 excretion, i.e. below or above a defined cutoff (< or > 328.98 ng/g creatinine). The predicted response to immunosuppression therapy was 34.5 and 100% in the low- and high-uCD80 excretion, respectively (p < 0.001). Progression to CKD was 41.4 vs. 2.9% in NS patients (p < 0.001). Using the Cox model, only uCD80 excretion (p = 0.013, relative risk 6.171) predicted progression to CKD., Conclusions: Urinary CD80 predicts progression and remission in children with NS. The use of uCD80 as a prognostic marker facilitates the identification of high-risk patients at an early stage and may lead to better treatment selection.

We report a case of 56-year-old man presented to us with chief complaints of frothy urine and leg swelling. A urinalysis revealed nephrotic-range proteinuria. Haematological investigations revealed thrombocytosis, leucocytosis and peripheral blood smear showed a leucoerythroblastic picture. JAK 2 mutation was positive. To confirm the diagnosis of myeloproliferative neoplasm, bone marrow biopsy was done, which was suggestive of primary myelofibrosis. The patient underwent kidney biopsy due to rapidly declining renal function and persistent proteinuria, which was suggestive of focal segmental glomerulosclerosis. Early glomerulopathy is rare in myeloproliferative neoplasm, and aggressive follow-up is required to prevent progression of kidney disease., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Urinary miRNAs may potentially serve as noninvasive biomarkers in various kidney diseases to reflect disease activity, severity and progression, especially those correlated with the pathogenesis of kidney diseases. This study demonstrates that urinary miR-196a, a kidney-enriched miRNA, can predict progression of chronic kidney disease (CKD)., Methods: Focal segmental glomerulosclerosis (FSGS) cohorts were used as the representative example of CKD. First, correlation of miR-196a with disease activity was analyzed using paired urine and plasma samples from FSGS patients with nephrotic-range proteinuria (FSGS-A), complete remission (FSGS-CR) and normal controls (NCs). Then, the value of urinary miR-196a in predicting disease progression was validated using another cohort of 231 FSGS patients who were followed-up until over 36 months or reaching end-stage renal disease (ESRD). MiR-196a levels were analyzed by quantitative reverse transcription-polymerase chain reaction., Results: The results showed that urinary miR-196a significantly increased in FSGS-A compared with FSGS-CR and NCs, clearly distinguishing FSGS-A from FSGS-CR and NCs, whereas plasma miR-196a showed no difference among these groups. Moreover, urinary miR-196a, which was associated with proteinuria, estimated glomerular filtration rate (eGFR), interstitial fibrosis and tubular atrophy, significantly increased in patients progressed to ESRD compared to those not. Furthermore, patients with higher urinary miR-196a displayed poorer renal survival than those with lower urinary miR-196a. Multivariate Cox analysis confirmed urinary miR-196a as an independent risk factor for FSGS progression after adjusting for age, sex, proteinuria and eGFR. Prediction accuracy of ESRD was significantly improved by combining urinary miR-196a with other indicators including eGFR and proteinuria., Conclusion: Urinary miR-196a may serve as a biomarker for predicting CKD progression.

Background: Focal segmental glomerulosclerosis (FSGS) is often accompanied with tubulointerstitial lesion. This study aimed to assess the role of urinary biomarkers in predicting tubulointerstitial lesion and treatment response in FSGS patients., Methods: Urinary neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), N-acetyl-β-d-glucosaminidase (NAG) and retinol-binding protein (RBP) were measured in 32 FSGS patients and 22 patients with minimal change nephrotic syndrome. Patients with FSGS were followed up to investigate the value of these markers in predicting treatment response., Results: FSGS patients had higher urinary NGAL, NAG and RBP than patients with minimal change nephrotic syndrome with comparable proteinuria. A cutoff value of 15.87ng/mL NGAL demonstrated 87.1% sensitivity and 59.1% specificity for the diagnosis of FSGS, with an area under the receiver operator characteristic curve of 0.801. In FSGS, these markers correlated significantly with the degree of acute tubulointerstitial damage but not with chronic tubulointerstitial lesion. Response to immunosuppressive therapy was significantly different in patients with KIM-1, NAG and RBP levels below and above the cutoff values., Conclusions: Urinary NGAL, KIM-1, NAG and RBP are reliable biomarkers of tubulointerstitial lesion in FSGS patients. The measurements of these markers may be useful in diagnosing FSGS, detecting acute tubulointerstitial lesion and predicting treatment response., (Copyright © 2018 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Focal segmental glomerulosclerosis (FSGS) comprises a group of uncommon disorders that present with marked proteinuria, nephrotic syndrome, progressive renal failure and characteristic glomerular lesions on histopathology. The current standard of care for patients with FSGS include immunosuppressive drugs such as glucocorticoids followed by calcineurin inhibitors, if needed for intolerance or inadequate response to glucocorticoids. Renin-angiotensin-aldosterone (RAAS) blockers are also used to control proteinuria, an important signature of FSGS. Existing treatments, however, achieved only limited success. Despite best care, treatment failure is common and FSGS is causal in a significant proportion of end stage renal disease. Thus, an unmet need exists for novel disease modifying treatments for FSGS. We employed two widely-used murine models of FSGS to test the hypothesis that systemic inhibition of chemokine receptor CCR2 would have therapeutic benefit. Here we report that administration CCX872, a potent and selective small molecule antagonist of CCR2, achieved rapid and sustained attenuation of renal damage as determined by urine albumin excretion and improved histopathological outcome. Therapeutic benefit was present when CCX872 was used as a single therapy, and moreover, the combination of CCX872 and RAAS blockade was statistically more effective than RAAS blockade alone. In addition, the combination of CCR2 and RAAS blockade was equally as effective as endothelin receptor inhibition. We conclude that specific inhibition of CCR2 is effective in the Adriamycin-induced and 5/6 nephrectomy murine models of FSGS, and thus holds promise as a mechanistically distinct therapeutic addition to the treatment of human FSGS.

Background and Objectives: Proteinuria is used as an indicator of FSGS disease activity, but its use as a clinical trial end point is not universally accepted. The goal of this study was to refine proteinuria definitions associated with long-term kidney survival., Design, Setting, Participants, & Measurements: Data on 466 patients with primary FSGS with proteinuria (urine protein-to-creatinine ratio >1 g/g) were analyzed from five independent cohorts. Proteinuria by months 1, 4, and 8 after study baseline was categorized by conventional definitions of complete (<0.3 g/g) and partial remission (<3.5 g/g and 50% reduction in proteinuria). Novel remission definitions were explored using receiver operating curves. Kaplan-Meier methods were used to estimate the associations of proteinuria with progression to ESRD or a 50% loss in kidney function. Propensity score-adjusted Cox proportional hazards models were used to adjust for baseline proteinuria, eGFR, and therapy., Results: In the initial derivation cohort, conventional partial remission was not associated with kidney survival. A novel definition of partial remission (40% proteinuria reduction and proteinuria<1.5 g/g) on the basis of receiver operating curve analyses of 89 patients was identified (Sensitivity=0.70; Specificity=0.77). In the validation cohort analyses, complete remission was associated with better prognosis (6 out of 41 patients progressed to kidney failure; 6.6 per 100 patient-years) as was the novel partial remission (13 out of 71 progressed; 8.5 per 100 patient-years), compared with those with no response (51 out of 116 progressed; 20.1 per 100 patient-years). Conventional partial remission at month 8, but not month 4, was also associated with better response (19 out of 85 patients progressed; risk=10.4 per 100 patient-years). Propensity score-adjusted analyses showed the novel partial remission was associated with less progression at months 4 and 8 (month 4: hazard ratio, 0.50; P =0.01; month 8: hazard ratio, 0.30; P =0.002)., Conclusions: Reaching either a complete or partial remission using a novel or conventional definition was associated with better long-term outcomes in patients with FSGS., Podcast: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018&#95;02&#95;20&#95;CJASNPodcast&#95;18&#95;3&#95;T.mp3., (Copyright © 2018 by the American Society of Nephrology.)

Introduction: Early diagnosis of minimal change disease (MCD) is challenging in nephrotic children. CD80 is a protein expressed on the surface of podocytes associated with nephrotic syndrome and it is implicated in the induction of proteinuria. This study aimed to investigate the use of urinary CD80 for the diagnosis of MCD., Materials and Methods: Urinary CD80 levels were evaluated in 36 children with nephrotic syndrome and normal glomerular filtration rate. They were divided into three groups of MCD (n = 21), focal segmental glomerulosclerosis (n = 9), and other glomerulopathies (n = 6). The MCD group was subdivided into 2 of those with remission (n = 11) and those in the active stage (n = 10). Forty healthy children were included as controls., Results: The urinary CD80 level was significantly higher in the MCD group (3.5 ± 2.1 ng/mg creatinine) than in the focal segmental glomerulosclerosis group (1.2 ± 0.5 ng/mg creatinine, P < .001), the other glomerulopathies group (1.4 ± 0.7 ng/mg creatinine, P < .001), and the control group (0.7 ± 0.2 ng/mg creatinine, P < .001), while it showed no significant difference among the non-MCD groups. There was no significant difference between MCD in remission and MCD in relapse, either. A urinary CD80 cutoff value of 1.5 ng/gm creatinine showed a sensitivity of 100% and a specificity of 86% for diagnosis of MCD., Conclusions: Urinary CD80 levels were significantly higher in the children with MCD than in the controls and patients with other causes of nephrotic syndrome.

Focal segmental glomerulosclerosis (FSGS) is a pathological lesion rather than a disease, with a diverse etiology. FSGS may result from genetic and non‑genetic factors. FSGS is considered a podocyte disease due to the fact that in the majority of patients with proven‑FSGS, the lesion results from defects in the podocyte structure or function. However, FSGS does not result exclusively from podocyte‑associated genes, however also from other genes including collagen IV‑associated genes. Patients who carry the collagen type IVA3 chain (COL4A3) or COL4A4 mutations usually exhibit Alport Syndrome (AS), thin basement membrane neuropathy or familial hematuria (FH). Previous studies revealed that long‑time persistent microscopic hematuria may lead to FSGS. A case of a family is presented here where affected individuals exhibited FH with FSGS‑proven, or chronic kidney disease. Renal biopsies were unhelpful and failed to demonstrate glomerular or basement membrane defects consistent with an inherited glomerulopathy, and therefore a possible underlying genetic cause for a unifying diagnosis was pursued. Genomic DNA of the siblings affected by FH with biopsy‑proven FSGS was analyzed, and their father was screened for 18 gene mutations associated with FSGS [nephrin, podocin, CD2 associated protein, phospholipase C ε, actinin α 4, transient receptor potential cation channel subfamily C member 6, inverted formin, FH2 and WH2 domain containing, Wilms tumor 1, LIM homeobox transcription factor 1 β, laminin subunit β 2, laminin subunit β 3, galactosida α, integrin subunit β 4, scavenger receptor class B member 2, coenzyme Q2, decaprenyl diphosphate synthase subunit 2, mitochondrially encoded tRNA leucine 1 (UUA/G; TRNL1) and SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a like 1] using matrix‑assisted laser desorption/ionization time‑of‑flight mass spectrometry technology. Then whole exome sequencing (WES) was performed in the two probands to ascertain whether there were other known or unknown gene mutations that segregated with the disease. Using mass array technology, a TRNL1 missense homozygous mutation (m. 3290T>C) was identified in the probands diagnosed with FH and manifested as FSGS on biopsy. In addition, a COL4A4 missense mutation c. 4195A>T (p. M1399L) in heterozygous pattern was identified using WES. None of these variants were detected in their father. In the present study, a mutation in TRNL1 (m. 3290T>C) was identified, which was the first reported variant associated with FSGS. The COL4A4 (c. 4195A>T) may co‑segregate with FSGS. Screening for COL4A mutations in familial FSGS patients is suggested in the present study. Genetic investigations of families with similar clinical phenotypes should be a priority for nephrologists. The combination of mass array technology and WES may improve the detection rate of genetic mutation with a high level of accuracy.

Nephrotic syndrome is not a single disease; rather, it is a term for numerous diseases and pathological types. Renal biopsy is of use in determining the diagnosis and prognosis, and for guiding treatment; however, the use of this intervention is limited due to its invasive nature. Abnormal kidney‑derived proteins in the urine of patients provide useful information regarding numerous pathological processes that occur in the kidneys, and may be considered a potential non‑invasive biomarker for kidney disease. Proteomic analysis exhibits the advantage of being high‑throughput and has previously been used to identify biomarkers of disease. The present study aimed to identify abnormal kidney‑derived proteins in the urine of patients with nephrotic syndrome using a novel proteomic strategy. Urine samples from 5 patients with nephrotic syndrome were subjected to acetone precipitation and albumin/immunoglobulin G depletion prior to analysis by two‑dimensional liquid chromatography tandem mass spectrometry. The resulting data were compared to a publicly available proteomic database of normal human plasma/urine and normal human kidney in PeptideAtlas, and of normal human kidney in the Human Protein Atlas. Candidate biomarkers were validated using ELISA analysis in 60 patients with nephrotic syndrome: 30 with focal segmental glomerulosclerosis (FSGS) and 30 with minimal change disease (MCD), as well as in 30 healthy controls. The initial screening identified 809 proteins in the urine of patients with nephrotic syndrome. A total of 13/809 proteins were additionally present in the kidney proteome of PeptideAtlas and the Human Protein Atlas, although not in normal human urine and normal human plasma according to PeptideAtlas; these were referred to as 'kidney‑derived disease‑associated proteins'. One of the kidney‑derived disease‑associated proteins, ubiquitin‑60S ribosomal protein L40 (UBA52) was observed to be increased in the urine of patients compared with normal controls [Creatinine, 637 ng/mg (216‑1,851) vs. 1.89 ng/mg (1.37‑3.33), P<0.001; and 18.58 ng/mg (11.11‑46.25) vs. 1.89 ng/mg (1.37‑3.33), P<0.001)], and the urinary UBA52 levels were significantly increased in patients with FSGS compared with in patients with MCD (P<0.001). In conclusion, the present study identified potential novel urinary protein biomarkers for nephrotic syndrome, in addition to an extensive urinary proteomic profile of patients with nephrotic syndrome.

Background: Patients with immunoglobulin A nephropathy (IgAN) who present with mild to moderate proteinuria and normal renal function are assumed to have excellent short-term renal prognosis, but the long-term prognosis is uncertain., Methods: Patients were selected from the Norwegian Kidney Biopsy Registry based on the following criteria: diagnostic renal biopsy performed in the period 1988-99, with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 and proteinuria <1 g/24 h at the time of biopsy. Patients were invited for a nephrological examination with a review of medical history and investigation of blood pressure, urinary findings and eGFR., Results: A total of 145 patients attended the examination, performed by the first author, after a median of 22 (interquartile range 19-25) years after diagnosis. At the examination, 27 patients (18.6%) had a ≥50% decrease in GFR, of whom 4 (2.8%) had developed end-stage renal disease (ESRD). The mean duration from renal biopsy to ≥ 50% decrease in GFR was 17.3 ± 5.1 years in our cohort. Clinical remission was observed in 42 (29.0%) patients. Renal biopsies were re-examined utilizing the Oxford classification criteria. Mesangial hypercellularity was found in 12.3%, endocapillary proliferation was detected in 10.7% and segmental glomerulosclerosis was observed in 23.8%. All biopsies were scored as T0 (tubular atrophy in < 25% of the cortical area). None of the clinical or histopathological variables recorded at the time of biopsy could identify patients with progressive disease. Cumulative risks of ≥50% decrease in eGFR were 2.1% after 10 years, 4.1% after 15 years, 13.9% after 20 years and 24.7% after 25 years., Conclusions: We have shown that 18.6% of patients with assumed benign IgAN had progressive disease after a median duration of 22 years and that these patients could not be predicted at the time of biopsy. Our study demonstrates that an extended follow-up period is needed when assessing prognosis in this group of patients., (© The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

The pathophysiology of many proteinuric kidney diseases is poorly understood, and microRNAs (miRs) regulation of these diseases has been largely unexplored. Here, we tested whether miR-378a-3p is a novel regulator of glomerular diseases. MiR-378a-3p has two predicted targets relevant to glomerular function, the glomerular basement membrane matrix component, nephronectin (NPNT), and vascular endothelial growth factor VEGF-A. In zebrafish (Danio rerio), miR-378a-3p mimic injection or npnt knockdown by a morpholino oligomer caused an identical phenotype consisting of edema, proteinuria, podocyte effacement, and widening of the glomerular basement membrane in the lamina rara interna. Zebrafish vegf-A protein could not rescue this phenotype. However, mouse Npnt constructs containing a mutated 3'UTR region prevented the phenotype caused by miR-378a-3p mimic injection. Overexpression of miR-378a-3p in mice confirmed glomerular dysfunction in a mammalian model. Biopsies from patients with focal segmental glomerulosclerosis and membranous nephropathy had increased miR-378a-3p expression and reduced glomerular levels of NPNT. Thus, miR-378a-3p-mediated suppression of the glomerular matrix protein NPNT is a novel mechanism for proteinuria development in active glomerular diseases., (Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Background: The aims of this study were (1) to detect toll-like receptor (TLR)-3, TLR-4 and CD80 expression in peripheral blood mononuclear cells (PBMCs) and estimate urinary CD80 levels in children with idiopathic nephrotic syndrome and (2) to investigate the utility of these markers to differentiate between biopsy-proven minimal change disease (MCD) and focal segmental glomeruloscelerosis (FSGS)., Methods: The study included 70 patients with idiopathic nephrotic syndrome (NS), of whom 40 had steroid-sensitive NS (SSNS; 25 with active NS, 15 in remission) and 30 had steroid-resistant NS (SRNS) patients, and 23 healthy controls. TLR-3, TLR- 4 and CD80 mRNA expression levels in PBMCs were determined and the urinary CD80 level estimated., Results: Median TLR-3, TLR-4 and CD80 mRNA expression levels were higher in patients with active SSNS than in those with SRNS, and the latter patient group also had significantly lower expression levels than the controls. The expression levels of these markers were associated with reductions in remission. Patients with biopsy-proven MCD had higher median expression levels of these markers than those with FSGS, but the differences were not statistically significant. Median urinary CD80/creatinine values were significantly higher in patients with SSNS and SRNS than in the controls and steroid-sensitive patients in remission (p < 0.001). CD80 levels were also significantly higher in patients with MCD than in those with FSGS (p = 0.002). A cut-off level of >914.5 ng/g had a sensitivity of 86.6%, specificity 71.4% and area under the curve of 0.828 (95% confidence interval 0.678-0.978, p = 0.002) for the diagnosis of MCD., Conclusions: Increased expressions of TLR-3, TLR-4 and CD80 mRNA and the level of urinary CD80/creatinine could be useful markers to differentiate patients of SSNS in relapse from those with SRNS. Further these markers can also distinguish biopsy proven MCD from FSGS in SRNS patients.

Background: Low birthweight infants have a reduced number of nephrons and are at high risk of chronic kidney disease. Preterm birth and/or intrauterine growth restriction (IUGR) may also affect peritubular capillary development, as has been shown in other organs., Case-Diagnosis/treatment: We report two patients with a history of preterm birth and extremely low birthweight who showed polycythemia and renal capillary rarefaction. Patient 1 and 2, born at 25 weeks of gestation with a birthweight of 728 and 466 g, showed mild proteinuria at age 8 and 6 years, respectively. In addition to increasing proteinuria, hemoglobin levels became elevated towards adolescence and their serum erythropoietin (EPO) was high despite polycythemia. Light microscopic examination of renal biopsy specimens showed glomerular hypertrophy, focal segmental glomerulosclerosis, and only mild tubulointerstitial fibrosis. A decrease in the immunohistochemical staining of CD31 and CD34 endothelial cells in renal biopsy specimens was consistent with peritubular capillary rarefaction., Conclusions: Since kidney function was almost normal and fibrosis was not severe, we consider that the capillary rarefaction and polycythemia associated with elevated EPO levels were largely attributable to preterm birth and/or IUGR.

Background: Minimal Change Disease (MCD) is the most common type of nephrotic syndrome in children. Angiopoietin-like-4 (Angplt4) has been proposed as mediator of proteinuria in MCD. The aim of this study was to evaluate the role of Angptl4 as a biomarker in MCD., Methods: Patients with biopsy-proven primary MCD, focal segmental glomerulosclerosis, membranous nephropathy (60, 52 and 52 respectively) and 18 control subjects had urinary and serum Angptl4 measured by Elisa. Frozen kidney tissue sections were stained for Angptl4., Results: Angptl4 was not identified in glomeruli of MCD patients in relapse. Urinary Angptl4 levels were elevated in MCD in relapse as well as in patients with massive proteinuria due to other glomerular diseases., Conclusion: Neither serum nor urine Angptl4 appear to be good biomarkers in MCD. Elevated urinary Angptl4 n glomerular disease appears to reflect the degree of proteinuria rather than any specific disease.

Background: Minimal change disease (MCD) and primary focal segmental glomerulosclerosis (FSGS) are glomerular diseases characterized by nephrotic syndrome. Their diagnosis requires a renal biopsy, but it is an invasive procedure with potential complications. In a small biopsy sample, where only normal glomeruli are observed, FSGS cannot be differentiated from MCD. The correct diagnosis is crucial to an effective treatment, as MCD is normally responsive to steroid therapy, whereas FSGS is usually resistant. The purpose of our study was to discover and validate novel early urinary biomarkers capable to differentiate between MCD and FSGS., Methods: Forty-nine patients biopsy-diagnosed of MCD and primary FSGS were randomly subdivided into a training set (10 MCD, 11 FSGS) and a validation set (14 MCD, 14 FSGS). The urinary proteome of the training set was analyzed by two-dimensional differential gel electrophoresis coupled with mass spectrometry. The proteins identified were quantified by enzyme-linked immunosorbent assay in urine samples from the validation set., Results: Urinary concentration of alpha-1 antitrypsin, transferrin, histatin-3 and 39S ribosomal protein L17 was decreased and calretinin was increased in FSGS compared to MCD. These proteins were used to build a decision tree capable to predict patient's pathology., Conclusions: This preliminary study suggests a group of urinary proteins as possible non-invasive biomarkers with potential value in the differential diagnosis of MCD and FSGS. These biomarkers would reduce the number of misdiagnoses, avoiding unnecessary or inadequate treatments.

Background . Glomerular upregulation of miR-193a has been detected in primary focal segmental glomerulosclerosis (FSGS) but not in other glomerular diseases. We aimed to isolate exosomes from urine of children with primary FSGS and to assess the diagnostic potential of urinary exosomal miR-193a for primary FSGS. Methods . The first morning urine samples were collected from children with primary FSGS ( n = 8) and minimal change disease (MCD, n = 5). Isolated urinary exosomes were confirmed by electron microscopy and Western blotting. Urinary exosomal microRNA was extracted, and the expression levels of exosomal miR-193a were quantified by real-time PCR. The diagnosis value of urinary exosomal miR-193a levels for primary FSGS was evaluated by ROC analysis. Results . The isolated vesicles were qualitatively compatible with exosomes. The levels of urinary exosomal miR-193a were significantly higher in children with primary FSGS than those in children with MCD. Moreover, the area under the ROC for the diagnosis of primary FSGS using urinary exosomal miR-193a was 0.85. Conclusions . A significant increase in the levels of urinary exosomal miR-193a in primary FSGS patients compared to those in MCD ones was observed. This study suggests that urinary exosomal miR-193a may be a new noninvasive biomarker for the diagnosis of primary FSGS., Competing Interests: The authors declare no conflict of interests.

Background: A beneficial effect of rituximab (RTX) on focal segmental glomerulosclerosis (FSGS) in pediatric patients or in transplant recipients has been reported in isolated cases. However, the use of RTX in adult patients with idiopathic FSGS needs further investigation., Methods: Eight patients who had biopsy-proven FSGS (63.9 ± 14.0, range 40-81 years, 4 women, 4 men) with major risk factors precluding corticosteroids or conventional immunosuppression were treated with a high dose of RTX (8 weekly doses of 375 mg/m2) and prospectively followed up for at least 2 years (29.1 ± 8.8 months, range 24-42 months)., Results: RTX failed to improve proteinuria in 7 out of 8 patients, who had persistent nephrotic proteinuria. In one case, a rapidly deteriorating renal function was also observed. Only one patient showed an improvement in renal function and a remarkable reduction in proteinuria. There were no differences in clinical or laboratory characteristics or in the CD20 B lymphocyte count after RTX between the responder and the 7 nonresponder patients., Conclusions: Only a minority (1 of 8) in our series of adult patients with FSGS showed positive effects of high doses of RTX. Future studies are warranted to investigate more promising therapeutic options in the management of FSGS., (© 2017 S. Karger AG, Basel.)

Background: Primary focal segmental glomerulosclerosis (FSGS) is a common cause of nephrotic syndrome., Aims: The pathogenic steps leading to primary FSGS are still obscure, although evidence suggests that circulatory factor(s) are involved in the onset of disease., Results: Recent technical advances allow the analysis of miRNA expression in tissues and body fluids, leading to reports of miRNAs involved in the molecular mechanisms of FSGS-aetiopathogenesis. Moreover, investigations have also highlighted miRNAs that might serve as biomarkers for primary FSGS., Discussion/conclusions: The aim of this review was to summarize reports showing a direct relation between miRNAs and primary FSGS. In addition, the impact of identified miRNAs on treatment response, prediction of the disease onset as well as the regulation in different disease activities is summarized., (© 2016 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.)

Primary focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) are common types of primary glomerular disease; they share numerous clinical and pathological similarities but have different treatment regimens and prognoses. It is therefore necessary to distinguish between them and to explore the mechanism underlying their differences. Fibrinogen is reportedly involved in podocyte damage and in renal fibrosis in vitro and in animal models of kidney disease. We thus tested urinary fibrinogen, serum fibrinogen, and renal fibrinogen deposition levels in a cohort comprising 50 patients with FSGS and 40 patients with MCD. Our results suggested that urinary fibrinogen and renal interstitial fibrinogen deposition levels were significantly higher in the FSGS patients than in the MCD patients, while serum fibrinogen levels did not differ between the groups. Receiver operating characteristic (ROC) curve analysis showed an excellent diagnostic ability for urinary fibrinogen and a fair diagnostic ability for tubulointerstitial fibrinogen deposition in differentiating FSGS from MCD. Additionally, we found that urinary fibrinogen levels were positively correlated with the 24-h urine protein levels in patients with FSGS but not in patients with MCD. In conclusion, urinary fibrinogen and renal interstitial fibrinogen deposition is elevated in primary FSGS compared to MCD, which may be relevant to both diagnosis and pathogenesis., (Copyright © 2016. Published by Elsevier Inc.)