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Background: Minimal change disease and primary focal segmental glomerulosclerosis in adults, along with idiopathic nephrotic syndrome in children, are immune-mediated podocytopathies that lead to nephrotic syndrome. Autoantibodies targeting nephrin have been found in patients with minimal change disease, but their clinical and pathophysiological roles are unclear., Methods: We conducted a multicenter study to analyze antinephrin autoantibodies in adults with glomerular diseases, including minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, IgA nephropathy, antineutrophil cytoplasmic antibody-associated glomerulonephritis, and lupus nephritis, as well as in children with idiopathic nephrotic syndrome and in controls. We also created an experimental mouse model through active immunization with recombinant murine nephrin., Results: The study included 539 patients (357 adults and 182 children) and 117 controls. Among the adults, antinephrin autoantibodies were found in 46 of the 105 patients (44%) with minimal change disease, 7 of 74 (9%) with primary focal segmental glomerulosclerosis, and only in rare cases among the patients with other conditions. Of the 182 children with idiopathic nephrotic syndrome, 94 (52%) had detectable antinephrin autoantibodies. In the subgroup of patients with active minimal change disease or idiopathic nephrotic syndrome who were not receiving immunosuppressive treatment, the prevalence of antinephrin autoantibodies was as high as 69% and 90%, respectively. At study inclusion and during follow-up, antinephrin autoantibody levels were correlated with disease activity. Experimental immunization induced a nephrotic syndrome, a minimal change disease-like phenotype, IgG localization to the podocyte slit diaphragm, nephrin phosphorylation, and severe cytoskeletal changes in mice., Conclusions: In this study, circulating antinephrin autoantibodies were common in patients with minimal change disease or idiopathic nephrotic syndrome and appeared to be markers of disease activity. Their binding at the slit diaphragm induced podocyte dysfunction and nephrotic syndrome, which highlights their pathophysiological significance. (Funded by Deutsche Forschungsgemeinschaft and others.)., (Copyright © 2024 Massachusetts Medical Society.)

Primary glomerular disease (PGD) is an idiopathic cause of renal glomerular lesions that is characterized by proteinuria or hematuria and is the leading cause of chronic kidney disease (CKD). The identification of circulating biomarkers for the diagnosis of PGD requires a thorough understanding of the metabolic defects involved. In this study, ultra-high performance liquid chromatography-tandem mass spectrometry was performed to characterize the amino acid (AA) profiles of patients with pathologically diagnosed PGD, including minimal change disease (MCD), focal segmental glomerular sclerosis (FSGS), membranous nephropathy, and immunoglobulin A nephropathy. The plasma concentrations of asparagine and ornithine were low, and that of aspartic acid was high, in patients with all the pathologic types of PGD, compared to healthy controls. Two distinct diagnostic models were generated using the differential plasma AA profiles using logistic regression and receiver operating characteristic analyses, with areas under the curves of 1.000 and accuracies up to 100.0% in patients with MCD and FSGS. In conclusion, the progression of PGD is associated with alterations in AA profiles, The present findings provide a theoretical basis for the use of AAs as a non-invasive, real-time, rapid, and simple biomarker for the diagnosis of various pathologic types of PGD., (© 2024. The Author(s).)

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: Failure of the glomerular filtration barrier, primarily by loss of slit diaphragm architecture, underlies nephrotic syndrome in minimal change disease. The etiology remains unknown. The efficacy of B cell-targeted therapies in some patients, together with the known proteinuric effect of anti-nephrin antibodies in rodent models, prompted us to hypothesize that nephrin autoantibodies may be present in patients with minimal change disease., Methods: We evaluated sera from patients with minimal change disease, enrolled in the Nephrotic Syndrome Study Network (NEPTUNE) cohort and from our own institutions, for circulating nephrin autoantibodies by indirect ELISA and by immunoprecipitation of full-length nephrin from human glomerular extract or a recombinant purified extracellular domain of human nephrin. We also evaluated renal biopsies from our institutions for podocyte-associated punctate IgG colocalizing with nephrin by immunofluorescence., Results: In two independent patient cohorts, we identified circulating nephrin autoantibodies during active disease that were significantly reduced or absent during treatment response in a subset of patients with minimal change disease. We correlated the presence of these autoantibodies with podocyte-associated punctate IgG in renal biopsies from our institutions. We also identified a patient with steroid-dependent childhood minimal change disease that progressed to end stage kidney disease; she developed a massive post-transplant recurrence of proteinuria that was associated with high pretransplant circulating nephrin autoantibodies., Conclusions: Our discovery of nephrin autoantibodies in a subset of adults and children with minimal change disease aligns with published animal studies and provides further support for an autoimmune etiology. We propose a new molecular classification of nephrin autoantibody minimal change disease to serve as a framework for instigation of precision therapeutics for these patients., (Copyright © 2022 by the American Society of Nephrology.)

Background: Minimal change disease is a common cause of nephrotic syndrome in adults. Higher relapse rate put patients at risk of steroids toxicity due to long-term exposure. Rituximab has been suggested to maintain long time remission and withdraw steroids and other immunosuppressants with fewer adverse events. However, optimal dose and dosing interval have not been explored., Methods: Twenty-five patients were enrolled from 2017-10 to 2020-03 in Nanfang Hospital in China. Clinical and biological data were extracted from medical records and laboratory databases. Therapy composed of 375mg/m 2 rituximab once three weeks for 3 dose and corticosteroid was applied. Complete remission was defined as reduction of proteinuria to 0.3g/d. Remission rate, relapse rate, steroids used before and after rituximab therapy and adverse effects were documented at a mean time of 14.71 months., Results: Twenty-two patients achieved complete remission for an average of 3.26 months and only 3 patients experienced one relapse respectively during the follow-up period. The mean remission maintenance time was 11.6 months, and was 5 months after steroids withdrawal. Steroids dose at last follow-up was 6.09mg/d, which was significantly reduced compared to 28.15mg/d before rituximab. Relapse rate before and after rituximab was 1.43 and 0.1, respectively. Only four minor adverse events were recorded., Conclusions: Therapy consisted of 375mg/m 2 rituximab once three weeks for 3 dose combined with corticosteroid is effective in inducing remission in adult patients with minimal change disease. Both of the relapse rate and dose of steroids used are significantly decreased with fewer side effects.

Background: The recent success achieved with the use of B cell-depleting agents in some patients with minimal change nephrotic syndrome (MCNS) suggests an unexpected role for B lymphocytes in the pathogenesis of this immune-mediated glomerular disease. Nevertheless, no extensive B-cell phenotyping analysis has ever been performed in untreated adult patients soon after MCNS diagnosis., Methods: We investigated the distribution of the different B-cell subpopulations in 22 untreated adult patients with biopsy-proven MCNS [MCNS relapse (MCNS-Rel)]. We compared these data with those for 24 healthy controls, 13 MCNS patients in remission (with no specific treatment) and 19 patients with idiopathic membranous nephropathy (IMN)., Results: Patients with MCNS-Rel or IMN had higher proteinuria and lower serum albumin and gammaglobulin levels (P < 0.0001 for all comparisons) than MCNS patients in remission. Plasmablasts were the only B-cell subsets present at significantly higher levels in MCNS-Rel patients than in the patients of the other three groups (P < 0.05 for all comparisons). The lower albumin levels and higher proteinuria levels were positively correlated with the percentage of circulating plasmablasts (Spearman test's ρ = -0.54, P = 0.01 and ρ = 0.65, P = 0.002, respectively). Similarly, the increase of immunoglobulin M (IgM) and the decrease of IgG levels were significantly associated with the percentage of plasmablasts in MCNS-Rel patients (Spearman's ρ = 0.36, P = 0.01 and Spearman's ρ = -0.60, P = 0.01, respectively). Increased production of interleukin (IL)-21, IL-6 and B-cell activating factor (BAFF) in the serum of MCNS-Rel patients was found significantly correlated with the percentage of plasmablasts (ρ = 0.72, P = 0.0002, ρ = 0.49, P = 0.04 and ρ = 0.62, P = 0.009, respectively)., Conclusions: An increase in the proportion of circulating plasmablasts seems to be a hallmark of untreated MCNS in adult patients. Further studies are required to more precisely determine the phenotype and functions of these cells., (© The Author(s) 2020. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Introduction: Data on pathologic features with prognostic utility in adults with minimal change disease (MCD) are limited. We assessed the relationship between histologic chronic changes and clinical presentation and outcomes., Methods: The consecutive records of 79 patients with MCD and minimum of 6 months follow-up were retrospectively reviewed. Kidney survival was the primary endpoint (doubling serum creatinine or dialysis initiation). Secondary endpoints were time to remission and relapse. Total chronicity score was the sum of glomerulosclerosis (0-3), interstitial fibrosis (0-3), tubular atrophy (0-3), and arteriolosclerosis (0/1)., Results: The median renal chronicity score was 1; 77% had minimal (0-1), 18% mild (2-4), and 5% moderate (5-7) chronicity. Fifty percent had a null score; they were younger, had higher eGFR, similar proteinuria, better renal survival, and lower mortality. Mean kidney survival time was 5.7 (95% CI 5.2-6.2) years; 89% reached a form of remission at a median of 8 weeks; 31% relapsed at a mean of 26 months. Chronic changes severity predicted both relapses and kidney survival, each one-point increase in score raised with 27% the risk of relapse and with 31% the risk of dialysis initiation. Acute kidney injury (AKI) was present in 42% of the patients; they had more often mesangial proliferation, interstitial inflammation, tubular atrophy, arteriosclerosis, podocyte villous hypertrophy, and higher chronicity score., Conclusion: Standardized grading of chronicity was a predictor of kidney survival and disease relapse and was related to AKI. Older patients with severe nephrotic syndrome and with increased chronicity score could represent a high-risk category.

Background: Fatty acid-binding protein 4 (FABP4), but not FABP1 (liver-type FABP), is ectopically induced in injured glomerular endothelial cells, and urinary FABP4 (U-FABP4) level is associated with proteinuria and renal dysfunction in a general population., Methods: The clinical significance of U-FABP4 was investigated in 81 patients (male/female: 43/38, age: 57 ± 17 years) who underwent kidney biopsy., Results: U-FABP4 was negatively correlated with estimated glomerular filtration rate (eGFR) (r = - 0.56, P < 0.01) and was positively correlated with age, blood pressure, triglycerides, proteinuria (r = 0.58, P < 0.01), plasma FABP4 and urinary FABP1 (U-FABP1) (r = 0.52, P < 0.01). Multivariable regression analysis showed that eGFR, proteinuria and U-FABP1 were independent predictors of U-FABP4. The level of U-FABP4, but not that of proteinuria, eGFR or U-FABP1, in minimal change nephrotic syndrome (MCNS) was significantly lower than the level in membranous nephropathy (MN) and that in diabetic nephropathy. Receiver operating characteristic curve analysis indicated that U-FABP4 level ≤ 0.78 μg/gCr predicted MCNS in patients who had nephrotic-range proteinuria with a high level of accuracy. When divided by the median value of U-FABP4 at baseline in 33 of the 81 patients who could be followed up, the yearly change (post-pre) in eGFR in the low U-FABP4 group was significantly greater than that in the high U-FABP4 group (median: 11.0 vs. -5.0 mL/min/1.73m 2 /year)., Conclusions: U-FABP4 level is independently associated with proteinuria and renal dysfunction in patients with glomerular kidney disease. A low U-FABP4 level may predict MCNS in patients with nephrotic syndrome and would be a useful biomarker for differential diagnosis of MCNS and MN, which are common causes of nephrotic syndrome.

Background: Minimal change disease (MCD) is one of the major causes of nephrotic syndrome (NS). A confirmed MCD diagnosis mainly depends on renal biopsy at present, which is an invasive procedure with many potential risks. The overall incidence of complications caused by renal biopsy procedures has been reported as approximately 11 and 6.6% outside and within China, respectively. Unfortunately, there is currently no noninvasive procedure or practical classification method for distinguishing MCD from other primary glomerular diseases available., Method: A total of 1009 adult patients who underwent renal biopsy between January 2017 and November 2019 were enrolled in this study. Twenty-five parameters extracted from patient demographics, clinical manifestations, and laboratory test results were statistically analysed. LASSO regression analysis was further performed on these parameters. The parameters with the highest area under the curve (AUC) were selected and used to establish a logistic diagnostic prediction model., Results: Of the 25 parameters, 14 parameters were significantly different (P < 0.05). MCD patients were mostly younger (36 (22, 55) vs. 41 (28.75, 53)) and male (59% vs. 52%) and had lower levels of diastolic blood pressure (DBP) (79 (71, 85.5) vs. 80 (74, 89)) and IgG (5.42 (3.17, 6.36) vs. 9.38 (6.79, 12.02)) and higher levels of IgM (1.44 (0.96, 1.88) vs. 1.03 (0.71, 1.45)) and IgE (160 (46.7, 982) vs. 47.3 (19, 126)) than those in the non-MCD group. Using the LASSO model, we established a classifier for adults based on four parameters: DBP and the serum levels of IgG, IgM, IgE. We were able to clinically classify adult patients with NS into MCD and non-MCD using this model. The validation accuracy of the logistic regression model was 0.88. A nomogram based on these four classifiers was developed for clinical use that could predict the probability of MCD in adult patients with NS., Conclusions: A LASSO model can be used to distinguish MCD from other primary glomerular diseases in adult patients with NS. Combining the model and the nomogram potentially provides a novel and valuable approach for nephrologists to diagnose MCD, avoiding the complications caused by renal biopsy.

Background: The seroprevalence of human Parvovirus B19 (PVB19) is 70-85% in adults worldwide. PVB19 is the etiologic agent of the fifth disease, is a cause of aplastic anemia, and can be associated with kidney injury. We aimed to describe the cases of 4 patients with kidney injury related to PVB19 primary infection, and to evaluate the seroprevalence of PVB19 and the incidence of PVB19 primary infection in patients undergoing a native kidney biopsy., Methods: Cases of PVB19 infection with kidney injury were reviewed from the archives of the department of Nephrology. A systematic screening of anti-PVB19 IgG and IgM antibodies and viral DNA was performed in sera from 100 consecutive patients with a kidney biopsy in 2017-2018., Results: The 4 patients with PVB19 infection-associated kidney disease displayed: one lupus-like glomerulonephritis (GN) without lupus auto-antibodies, one minimal change disease with tubular necrosis, one secondary hemolytic and uremic syndrome and one membrano-proliferative GN. In the 100 patients biopsied, 67 had elevated anti-PVB19 IgG, among whom 8 had elevated IgM, without circulating viral DNA, without any particular renal pathological pattern. One additional patient showed a seroconversion at the time of kidney biopsy, which revealed a class V lupus nephritis., Conclusion: PVB19 primary infection can be associated with different kidney diseases. The seroprevalence of PVB19 among patients with a kidney biopsy is similar to the overall population, and primary infection is rarely documented (1%) after systematic screening. Whether PV19 is nephrotoxic, or triggers renal endothelial injury and immune activation, remains to be elucidated.

Nowadays, the pathogenesis of minimal change disease (MCD) is still not well-known, and the current understanding on MCD is mainly based on data derived from children, and very few adults. Here, we comprehensively analysed the correlation between the changes of peripheral basophils and the incidence rate and relapse of adult-onset MCD. The results showed that in patients at the onset of MCD, the ratio and activation of basophils were all higher than those of healthy controls (all P < .05). In vitro test results showed that basophils from healthy controls can be activated by the serum taken from patients with MCD. Among 62 patients at the onset of MCD, with complete remission after treatment and 1 year of follow-up, the relative and absolute basophil counts before treatment were higher in the long-term remission group (n = 33) than that of the relapse group (n = 29). The basophil counts were significantly higher in the infrequent relapse group (n = 13) than that of the frequent relapse group (n = 16; P < .05). These findings suggested that basophil may play a pathogenic role in adult-onset MCD, and the increased number and activation of peripheral basophils could predict recurrence in adult MCD., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Circulating factors have been implicated in the pathogenesis of minimal change disease (MCD), and may have direct effects on cholesterol metabolism. This study investigated the pathogenesis of hypercholesterolemia in an IL-13 overexpression rat model of MCD prior to the onset of proteinuria, so as to establish the direct contribution of IL-13, especially with regard to hepatic cholesterol handling. In this model of MCD, the temporal relationship between hypercholesterolemia and proteinuria was first identified. Plasma proprotein convertase subtilisin/kexin type 9 (Pcsk9) and liver ATP-binding cassette sub-family G member 5 (Abcg5) were measured using ELISA. Liver Ldlr and liver X receptor alpha (Lxra) were quantified with Western blot. Abcg5-mediated cholesterol efflux in IL-13-stimulated rat primary hepatocytes was measured using taurocholate as cholesterol acceptor. The role of Lxra was validated using a luciferase assay in Lxre-luciferase-transfected IL-13-stimulated hepatocytes. IL-13-transfected rats developed hypercholesterolemia prior to proteinuria, with 35% of rats hypercholesterolemic but only 11% proteinuric by Day 20 (P = 0.04). These pre-proteinuric hypercholesterolemic rats showed elevations in total and LDL-cholesterol, but not hypertriglyceridemia or hepatic steatosis. The hypercholesterolemia was associated with increased hepatic Pcsk9 synthesis and enhanced circulating Pcsk9 levels, which correlated strongly with plasma total cholesterol (r = 0.73, P<0.001). The hypercholesterolemia was also contributed by decreased Abcg5 expression and activity, due to reduced Lxra expression. Lxra expression correlated with plasma total cholesterol levels (r = -0.52, P = 0.01), and overexpression of pLxra in rat hepatocytes abrogated the IL-13-mediated down-regulation of Lxre-driven gene expression. In conclusion, we have shown that IL-13 induced changes in hepatic cholesterol handling in a cytokine-induced rat model of MCD, resulting in hypercholesterolemia which can precede the onset of proteinuria., (© 2020 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Nephrotic syndrome (NS) is one of the most common kidney diseases seen in children. It is a disorder characterized by severe proteinuria, hypoproteinemia, hyperlipidemia, and generalized edema resulting from alterations of permeability at the glomerular capillary wall. Endothelin-1 (ET1) has a central role in the pathogenesis of proteinuria and glomerulosclerosis and has a role in assessment of the clinical course of NS in children. This study aims to investigate the relationship between ET1 serum level and the response to steroid therapy in children with primary NS. Serum ET1 levels were evaluated in 55 children with NS. They were classified into two groups: 30 patients with steroid-sensitive NS (SSNS) and 25 patients with steroid-resistant NS (SRNS). The SSNS group was further divided into infrequent-relapsing NS (IFRNS) and steroid-dependent NS (SDNS), while the SRNS group was subdivided into two groups according to renal pathology. ET1 levels were significantly higher in the SRNS group (52.5 ± 45.8 pg/dL) compared to the SSNS group (18.3 ± 17 pg/dL) (P <0.001). Furthermore, ET1 levels were significantly higher in SDNS (54.3 ± 18.6) compared to IFRNS (11.9 ± 7.8, P = 0.001). There was no statistically significant difference in ET1 levels between minimal change disease group and focal segmental glomerulosclerosis group, (P = 0.28). Serum ET1 can be considered as a predictor for response to steroid therapy.

Background: The increase of circulating urokinase plasminogen activator receptor (suPAR) was demonstrated in various diseases showing its prognostic value as well as the link to the inflammatory reaction. In glomerular diseases, suPAR was considered a causative factor of proteinuria. In the present study we aimed to evaluate serum concentration of suPAR in children with primary and secondary glomerulonephritis (GN) and its association with disease severity., Methods: The study involved 22 children with minimal change disease (MCD), nine with primary focal segmental glomerulosclerosis (FSGS), seven with Henoch-Schönlein nephritis, seven with lupus nephritis (LN) and 16 controls., Results: Serum suPAR was significantly higher in children with FSGS and LN than controls (4.47±1.39 ng/mL vs. 3.23±0.76 ng/mL; P=0.011 and 6.17±1.12 ng/mL vs. 3.23±0.76 ng/mL, respectively; P<0.0001). Further, suPAR was increased in LN when compared to FSGS (P=0.031). In the total group suPAR showed negative correlation with eGFR, serum complement C3 and positive with left ventricular mass index. In children with MCD and FSGS the inverse association of suPAR with eGFR was also shown., Conclusions: In children with primary and secondary glomerulonephritis suPAR levels are not associated with proteinuria. In primary GN elevated suPAR levels may result from reduced eGFR reflecting renal damage. In LN circulating suPAR can be increased further indicating both multi-organ involvement and systemic inflammation reflecting disease severity.

Background: Immunosuppressive treatment will predispose an idiopathic membranous nephropathy (iMN) patient to opportunistic infections. Disease severity is one of the main concerns for making the treatment decision. Urinary angiotensinogen (UAGT) level has been shown highly correlated with intrarenal renin-angiotensin system (RAS) activity and severity of chronic kidney diseases (CKD). We aimed to test the relationship between the UAGT level and the severity of iMN., Methods: This cross-sectional study included a total of 48 biopsy-proven iMN patients, 46 minimal change disease (MCD) patients, and 44 healthy volunteers. The clinical and laboratory data and urine samples were collected from all subjects before the use of RAS inhibitors. We determined the UAGT levels with a method of enzyme-linked immunosorbent assay., Results: The UAGT levels were not different between the iMN (277.05 ± 61.25, μg/g.Cr) and MCD patients (244.19 ± 40.24, μg/g.Cr), but both of them were significantly higher than those of healthy controls (6.85 ± 1.10, μg/g.Cr). UAGT levels were correlated negatively with serum albumin (r = - 0.393, p = 0.006) and estimated glomerular filtration rate (eGFR) (r = - 0.352, p = 0.014) and positively with 24-h proteinuria (r = 0.614, p < 0.001) in iMN patients but not in MCD patients. Multivariate linear regression analysis revealed that only proteinuria independently determinate the levels of UAGT (β = 0.649, p < 0.001) in iMN patients., Conclusions: UAGT levels were correlated negatively with serum albumin and glomerular filtration rate and positively with proteinuria in iMN patients at the onset. This suggests that elevated levels of UAGT are associated with the severity of iMN. The UAGT level may be used as a cofactor for deciding immunosuppressive therapy in iMN patient.

Background: Kimura's disease (KD) is a rare chronic inflammatory disorder with a high incidence of renal involvement. In this report, we present a case study of KD-associated nephrotic syndrome combined with minimal change disease (MCD) and acute renal tubular injury. Meanwhile, the clinical and histopathological characteristics of 26 patients with KD presenting with renal involvement were retrospectively evaluated., Case Presentation: Here, we report a case study of a 59-year-old male patient with KD confirmed by a lymph node biopsy. He developed widespread edema and decreased urine output. A palpable swollen mobile and non-tender lymph node behind the left ear was observed upon admission. A renal biopsy revealed minimal-change lesions and acute renal tubular injury. The patient received hemodialysis because of the oliguria and renal insufficiency, and an initial dose of 40 mg/d methylprednisolone and then continued treatment with 40 mg/d prednisolone. He exhibited a good clinical response to the steroid after 6 weeks of treatment. Of the other 26 patients included in the review, 13 patients presented with mesangial proliferative glomerulonephritis, 4 with membranous nephropathy, 3 with MCD, 3 with focal segmental glomerulosclerosis, 2 with IgA nephropathy and 1 with acute tubular injury. With the exception of 2 patients who progressed to end-stage renal disease and received hemodialysis, the majority of patients responded well to treatment with corticosteroids alone., Conclusions: MCD combined with acute renal tubular injury is rare in patients with KD presenting with renal involvement. Corticosteroids may be a beneficial treatment for renal injury in patients with KD.

Background: Immunoglobulin A nephropathy (IgAN), membranous nephropathy (MN) and minimal-change disease (MCD) are three common types of glomerulonephritis in China. Pathological diagnosis based on renal biopsy is the criterion and the golden standard for diagnosing the sub-types of primary or secondary glomerulonephritis. Immunoglobulin and complements might be used in the differential diagnosis of glomerulonephritis without renal biopsies. However, the relationship between IF intensities of immune proteins and the corresponding serum levels remained unclear, and seldom studies combine histopathological examination results and blood tests together for a predictive purpose. This study was considered as a pilot study for integrating histopathological indicators into serum parameters for exploring the relationship of IF intensity and serum values of immunoglobulin and complement, and for screening and investigating effective indicators inIgAN, MN and MCD., Methods: Renal tissue immunofluorescence (IF) intensity grades and serum levels of immunoglobulin and complements (IgG, IgA, IgM, C3 and C4) were retrospectively analyzed in 236 cases with IgAN, MN or MCD. IF grades were grouped as negative (-), positive (+) or strong positive (++) with both high and low magnification of microscope. Other serum indicators such as urea nitrogen (BUN), creatinine (Crea) and estimated glomerular filtration rate (eGFR) were also evaluated among the groups., Results: There were difference in IgA, IgG and C3 IF intensity grades among IgAN, MN and MCD groups (p = 9.82E-43, 4.60E-39, 7.45E-15, respectively). Serum values of BUN, Crea, eGFR, IgG, IgA, IgM and C4 showed difference in three groups (BUN: p = 0.045, Crea: p = 3.45E-5, eGFR: p = 0.005, IgG: p = 1.68E-14, IgA: p = 9.14E-9, IgM: p = 0.014, C4: p = 0.026). eGFR had the trend to decrease with enhanced IgA IF positive grades (p = 8.99E-4); Crea had trends to decrease with both enhanced IgA and IgG IF intensity grades (p = 2.06E-6, 2.94E-5, respectively). In all subjects, serum IgA levels was inversely correlated with eGFR(r = - 0.216, p = 0.001) and correlated with Crea levels(r = 0.189, p = 0.004); serum IgG and Crea showed no correlation which were discordance with inverse correlation of IgG IF grade and Crea(r = 0.058,p = 0.379). IgG serum level was inverse correlated with its IF grades (p = 3.54E-5, p = 7.08E-6, respectively); C3 serum levels had significantly difference between Neg and positive (+) group (p = 0.0003). IgA serum level was positive correlated with its IF grades (Neg-(+): p = 0.0001; (+)-(++): p = 0.022; Neg-(++): p = 2.01E-10). After matching comparison among C3 groups, C3 Neg. group and C3 ++ group had difference (*p = 0.017). C4 had all negative IF expression in all pathological groups. In IgAN subjects, there were statistical differences of serum C3 levels between its pathological Neg and positive (+) group(p = 0.026), and serum IgA levels showed difference between IgA pathological positive(+) and (++)(p = 0.007). In MN subjects, sIgG levels showed difference between IgG pathological IF grade positive (+) and (++)(p = 0.044); serum C3 levels showed difference between C3 pathological IF grade Neg and positive(+)(p = 0.005); and serum IgA levels showed difference between Neg and positive(+)(p = 0.040). In IgAN, eGFR showed serum IgA levels had significant differences among groups (p = 0.007) and had increasing trend with enhanced its IF grades(P trend  = 0.016). There were also difference between IgG group Neg and positive (+) (p = 0.005, P trend  = 0.007) in IgAN. In MN, serum IgG levels had significant differences among IF groups (p = 0.034) and had decreasing trend with its enhanced IF grades (P trend  = 0.014). Serum C3 concentrations also were found distinctive among IF groups (p = 0.016) and had in inverse correlation with its enhanced IF grades (P trend  = 0.004)., Discussion: Our research cross contrasts several immunoprotein IF intensities and relevant serum levels in three kinds of primary glomerular nephritis, and finally acquired helpful results for understanding the relationships between pathological presentation and serological presentation of immunoproteins in kidney diseases. Furthermore, this pilot study is offering a possible method for the analysis of combination of pathology and serology., Conclusion: Different pathological types of nephritis presented different expression patterns of immunoglobulin and complement, especially IgA and IgG, which suggested different pathogenesis involved in the development of IgAN and MN. Furthermore, either in tissue or in serum, increased IgA level was closely related with renal function in all of the patients.

Background: In patients with adult minimal change disease (MCD), proteinuria relapse is a problem to solve. However, the optimal relapse treatment regimen remains unclear regarding steroid dose. We described the treatment pattern of adult MCD patients and evaluated the appropriate steroid dose for relapse treatment., Methods: This retrospective multicenter cohort study included 192 patients with adult biopsy-proven MCD from 14 hospitals in Japan. The prescription pattern of immunosuppressive drugs in relapse was reviewed. To assess the association between steroid dose used for relapse and subsequent outcomes, data of patients with tapered prednisolone (PSL) dosage to <10 mg/day before the first relapse in whom the dose was subsequently increased to ≥10 mg/day were extracted and assigned to the High-PSL or Low-PSL groups, based on the median dose of 20 mg/day. Multivariate Cox proportional hazard model and propensity score analysis with multiple imputations were conducted to compare their clinical course., Results: During a median observation period of 37.6 months, 186/192 (96.9%) patients achieved complete remission (CR) and 100 (52.1%) relapsed. The median urinary protein level at the first relapse was 3.12 g/gCr or g/day. The proportion of non-steroidal immunosuppressant use increased with relapses; cyclosporine was the most common. No significant differences were found in the second relapse, frequent relapses, or adverse events between High-PSL (n = 34) and Low-PSL (n = 36) groups. A multivariate Cox proportional hazard model revealed that the hazard ratios adjusted with propensity score for the second relapse were 0.94 (High-PSL vs. Low-PSL; 95% confidence interval, 0.42-2.10; P = 0.88) and 0.82 (PSL dose per 10 mg/day; 95% confidence interval, 0.58-1.16; P = 0.25)., Conclusions: Among patients in CR with PSL dose <10 mg/day, higher steroid dose (PSL >20 mg/day) was not associated with favorable outcomes after the first relapse as compared to lower dose (10-20 mg/day)., Competing Interests: This study was partly supported in part by a Grant-in-Aid for Intractable Renal Diseases Research, Research on rare and intractable diseases, Health and Labor Sciences Research Grants from the Ministry of Health, Labor, and Welfare of Japan. And Department of Nephrology, Nagoya University Graduate School of Medicine is supported by the following funders; Asahi Kasei Pharmaceutical Co, Alexion Pharmaceutical Co, Otsuka Pharmaceutical Co, Kissei Pharmaceutical Co, Novartis Pharma K.K, Kowa Pharmaceutical Co, Chugai Pharmaceutical Co, Nippon Boehringer Ingelheim Co., Ltd., Pfizer Japan Inc., Kyowa Hakko Kirin Co., Ltd., Torii Pharmaceutical Co.,Ltd, Astellas Pharma Inc., MSD K.K., Daiichi Sankyo Company Limited, Takeda Pharmaceutical Company Limited, Bristol-Myers Squibb, Mitsubishi Tanabe Pharma Corporation, Sumitomo Dainippon Pharma Co., Ltd., Teijin Pharma Limited, Mochida Pharmaceutical Co., Ltd and Baxter Limited. However, the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This does not alter the authors’ adherence to PLOS ONE policies on sharing data and materials.

Background: Minimal change nephrotic syndrome (MCNS) responds well to steroids, but some patients show frequent relapses. Long-term steroid administration leads to various adverse effects. We previously reported the effectiveness in refractory nephrosis patients of administrating microemulsified CyA (ME-CyA) once before meals and setting the target value of the CyA blood concentration at 2 h after ME-CyA administration (C2) to 600-1200 ng/ml. On this trial we evaluate the effectiveness and safety of ME-CyA for suppressing relapse of adult new-onset MCNS patients using C2 monitoring., Methods: Adult new-onset MCNS patients were randomly allocated to a ME-CyA + prednisolone group ("CyA + PSL") (n = 11) and a PSL-alone group ("PSL-alone") (n = 10). The drug administration period was 18 months followed by an observation period of 12 months., Results: The duration of remission tended to be longer in CyA + PSL with C2 >600 ng/ml than in PSL-alone (P = 0.112). The relapse rate up to 18 months was significantly lower in CyA + PSL with C2 >600 ng/ml than in PSL-alone (P = 0.02). C2 was significantly higher in the patients with no relapse at 18 months than that in the patients with relapse (P = 0.048). In CyA + PSL, the total dose of PSL was significantly reduced compared with PSL-alone (P = 0.002). Cosmetic adverse effects tended to be fewer in CyA + PSL., Conclusions: The combination treatment regimen of ME-CyA and PSL with C2 >600 ng/ml has potential to be an important treatment option for adult new-onset MCNS patients. However, after ME-CyA dosage reduction and discontinuation, the relapse rate increased. It is thus necessary to establish a better dose-reduction method.

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: Patients with minimal change nephrotic syndrome (MCNS) often also have allergic diseases. Abnormalities of Th2-derived cytokines and T-cell functions contribute to development of these diseases. On the other hand, imbalances between reactive oxygen species (ROS) and antioxidants have been implicated in MCNS and progression of atopic dermatitis. ROS, produced mainly within mitochondria, subject cells to oxidative stress, while prohibitin 2 protects mitochondria by increasing tolerance to ROS. Additionally, podocin, a member of the slit diaphragm protein complex, contains PHB-like domain that serves as a signaling platform regulating podocyte function through associated transmembrane proteins., Patients and Method: Then, we performed exome sequencing analysis in five patients with frequently relapsing their MCNS associated with allergic disease and serum IgE concentrations of 2000 IU/L or higher., Results: We detected a heterozygous prohibitin 2 polymorphism, c.873-3&#95;873-2 delCA (rs111523336), in 1 patient. This mutation in exon 9 caused frameshifts in regions connected to splicing sites, where they could disrupt transcription of prohibitin 2. Frequency of this polymorphism in exon 9 is 7.3% among Japanese. Increase in peripheral blood ROS even MCNS remission state suggests the heterozygous prohibitin 2 variant may contribute to give more susceptibility towards the recurrence of MCNS as well as atopic skin disease. This increase may have progression of atopic dermatitis, which sometimes heralded., Conclusion: The prohibitin-2 polymorphism may reduce ROS tolerance in glomerular epithelium and led to high local exposure to ROS, increasing permeability of the glomerular basement membrane to result in proteinuria. Imbalance between ROS and antioxidants together with failure of signal transduction in the glomerular slit membrane caused by prohibitin 2 abnormality could have contributed to nephrotic syndrome in our patients. Prohibitin 2 analysis is needed in additional MCNS patients with concomitant allergic disease.

Renal biopsy has been widely recommended in clinic to determine the histological patterns of kidney disease. To prevent bleeding complications, patients should routinely stop anticoagulants prior to renal biopsy. However, patients with kidney disease are susceptible to thromboembolisms, particularly in those with severe hypoalbuminemia. This study was designed to investigate the application of serum D-dimer as a predictor for thrombotic events after renal biopsy. 400 consecutive native renal biopsies were prospectively included in this 2-month follow-up study. The overall incidence of bleeding and thrombotic complication is 4%, including hematuria or large perinephric hematoma (2.5%, n = 10) and thrombotic complication (1.5%, n = 6). Compared to low serum D-dimer (<2.00 μg/ml), subjects in the group of high serum D-dimer (≥2.00 μg/ml) were more incline to develop thrombotic complications (9.1% versus 0.3%; RR, 30.33; p < 0.001). D-dimer correlated positively with age (r s  = 0.258, P < 0.001). Inverse correlations were found for albumin (r s  = -0.339, P < 0.001). Taken together, patients with high serum D-dimer carry an increased risk of thrombotic complications after renal biopsy. Our findings suggest that serum D-dimer can serve as a potential predictor for thrombotic events in patients with kidney disease. Further cautions should be given to these subjects.

We describe a 66-year-old male with immunoglobulin G4-related disease (IgG4-RD) presenting with minimal change disease (MCD). Three years prior to this admission, the patient had been diagnosed with IgG4-RD. The development of sudden massive proteinuria (4+; 16.7 g/gCr) with a weight gain of 8 kg within a two-week period was noted, and nephrotic syndrome was suspected. The patient's serum IgG4 level did not increase and hypocomplementemia was not found. A renal biopsy showed no cellular infiltration in the renal interstitium, and no spiking or bubbling was found on periodic acid methenamine silver staining. On electron microscopy, foot process effacement was seen, but no subepithelial electron-dense deposits were found. The patient was diagnosed with MCD. Ten days after starting prednisolone (60 mg/day), proteinuria was negative. Since IgG4-RD and MCD share a T-helper 2-dominant immunoreaction, the development of MCD in IgG4-RD patients may reflect more than a mere coincidence.

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.

Minimal change disease (MCD) is the most common type of nephrotic syndrome in children and adolescents. The pathogenesis of proteinuria in this condition is currently being reassessed. Following the Shalhoub hypothesis, most efforts have been placed on identifying the putative circulating factor, but recent advancement in podocyte biology has focused attention on the molecular changes at the glomerular capillary wall, which could explain the mechanism of proteinuria in MCD. This report critically reviews current knowledge on the different postulated mechanisms at the glomerular capillary wall level for increased permeability to plasma proteins in MCD. The report helps describe the rationale behind novel therapies and suggests future targeted therapies for MCD.

Background: Myeloid-related protein 8/14 (MRP8/14) forms stable heterodimers and is the major calcium-binding protein secreted by activated granulocytes and monocytes. We evaluated whether serum MRP8/14 level is a useful indicator for a differential diagnosis of glomerulonephritis (GN)- and minimal change disease (MC)- related nephrotic syndrome (NS)., Methods: Serum MRP8/14 complex was evaluated in 37 NS patients with MC or GN. These patients were divided into two groups. Group 1 consisted of 13 NS patients with MC, and group 2 consisted of 24 NS patients with GN. Group 2 was further divided into four subgroups: IgA nephropathy (IgAN; n = 5), Henoch-Schönlein purpura nephritis (HSPN; n = 6), focal segmental glomerulosclerosis (FSGS; n = 12), and acute GN Poststreptococcal acute glomeruloNephritis (PSAGN; n = 1)., Results: The clinical manifestations, laboratory findings, serum MRP8/14 level, and renal accumulation of MRP8 were investigated for each group. No significant inter-group differences were observed for serum total protein, serum albumin, or blood urea nitrogen and urinary protein excretions. Mean serum MRP8/14 in the IgAN, HSPN, FSGS, and PSAGN groups was higher than in group 1. Further, the mean glomerular and interstitial MRP8 staining scores in the IgAN, HSPN, and PSAGN groups were higher than in group 1., Conclusions: Serum MRP8/14 level may be a useful indicator for differential diagnosis between GN- and MC- related NS., (© 2016 Japan Pediatric Society.)

Objectives: Soluble urokinase plasminogen activator receptor (suPAR), derived from membrane bound uPAR, is associated with inflammatory diseases. In the present study, we explored the expression of uPAR/suPAR in common biopsy-proven kidney diseases and the relationship between suPAR and staging of type 2 diabetic nephropathy (DN)., Design and Methods: Serum samples for suPAR and renal tissues for uPAR staining were investigated in various common kidney diseases. The levels of serum suPAR were measured and adequate cut-off values of different stage of DN were calculated by receiver operating characteristic (ROC) curve., Results: In our results, the expression of uPAR on renal tissues was pronounced in the majority of kidney diseases. Comparing of expression of uPAR among different kidney diseases, it was strongest in minimal change disease (MCD) and weakest in chronic interstitial nephritis. Serum suPAR in most kidney diseases, except of MCD, was significantly elevated and was highest in DN. As for DN and suPAR, we found that suPAR progressively increased with staging of DN. Moreover, suPAR was linearly and negatively related to estimated glomerular filtration rate and positively related to the amount of proteinuria. By ROC curve, the cut-off values of suPAR in DN for assessing development increased with the progression of the disease., Conclusions: We concluded that uPAR/suPAR is elevated in most kidney diseases and that suPAR is a useful biomarker for assessing stages of DN., (Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Objective: Human neutrophil peptides (HNP) were recently implicated in the neutrophil extracellular trap (NET) complex, the impaired degradation of which has been associated with lupus nephritis (LN)., Methods: Forty LN patients, 40 SLE patients without kidney injury, 63 immunoglobulin A nephropathy (IgAN) patients, 20 minimal change disease (MCD) patients and 33 healthy controls were included in the present study. LN, IgAN and MCD patients were diagnosed with renal biopsy. LN patients were followed for a median period of 5.5 years. Clinical and laboratory data at the time of renal biopsy and follow-up were collected for each LN patient. Serum levels of HNP1-3 were measured with enzyme-linked immunosorbent assay., Results: Serum HNP1-3 levels in LN patients were significantly higher than for SLE patients without kidney injury (P < 0.001), IgAN patients (P = 0.012), MCD patients (P = 0.010) and healthy controls (P = 0.022). Serum HNP1-3 levels were an independent indicator of LN (P = 0.006, OR = 7.5, 95% CI, 1.782-31.842), were statistically correlated with urinary protein excretion (P = 0.009) and activity index (P = 0.042) and were only marginally correlated with neutrophils (P = 0.054) and white blood cell counts (P = 0.051). Serum levels of HNP1-3 were a predictor of proteinuria remission after correction for multiple parameters (multivariate hazard 0.209; 95% CI 0.046-0.951; P = 0.043)., Conclusions: The data from this study indicated that HNP1-3, one component of the NET, is a potential biomarker for LN., (© 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.)

Background: MicroRNAs (miRNAs) are noncoding RNA molecules that play important roles in the pathogenesis of various kidney diseases. We investigated whether patients with minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) have distinct circulating and urinary miRNA expression profiles that could lead to potential development of noninvasive biomarkers of the disease., Materials and Methods: Exosome miRNAs were extracted from plasma and urine samples of patients with primary FSGS (n = 16) or MCD (n = 5) and healthy controls (n = 5). Differences in miRNA abundance were examined using Affymetrix GeneChip miRNA 3.0 arrays. QRT-PCR was used to validate the findings from the array., Results: Comparison analysis of FSGS versus MCD revealed 126 and 155 differentially expressed miRNAs in plasma and in urine, respectively. Only 38 of these miRNAs were previously cited, whereas the remaining miRNAs have not been described. Comparison analysis showed that a significant number of miRNAs were downregulated in both plasma and urine samples of patients with FSGS compared to those with MCD. Plasma levels of miR-30b, miR-30c, miR-34b, miR-34c and miR-342 and urine levels of mir-1225-5p were upregulated in patients with MCD compared to patients with FSGS and controls (P < 0.001). Urinary levels of mir-1915 and miR-663 were downregulated in patients with FSGS compared to MCD and controls (P < 0.001), whereas the urinary levels of miR-155 were upregulated in patients with FSGS when compared to patients with MCD and controls (P < 0.005)., Conclusions: Patients with FSGS and MCD have a unique circulating and urinary miRNA profile. The diagnostic and prognostic potential of miRNAs in FSGS and MCD warrants further studies., (© 2015 Stichting European Society for Clinical Investigation Journal Foundation.)

It has been suggested that soluble urokinase receptor (suPAR) is a causative circulating factor for and a biomarker of focal and segmental glomerulosclerosis (FSGS). Here we undertook validation of these assumptions in both mouse and human models. Injection of recombinant suPAR in wild-type mice did not induce proteinuria within 24 h. Moreover, a disease phenotype was not seen in an inducible transgenic mouse model that maintained elevated suPAR concentrations for 6 weeks. Plasma and urine suPAR concentrations were evaluated as clinical biomarkers in 241 patients with glomerular disease from the prospective, longitudinal multicenter observational NEPTUNE cohort. The serum suPAR concentration at baseline inversely correlated with estimated glomerular filtration rate (eGFR) and the urine suPAR/creatinine ratio positively correlated with the urine protein/creatinine ratio. After adjusting for eGFR and urine protein, neither the serum nor urine suPAR level was an independent predictor of FSGS histopathology. A multivariable mixed-effects model of longitudinal data evaluated the association between the change in serum suPAR concentration from baseline with eGFR. After adjusting for baseline suPAR concentration, age, gender, proteinuria, and time, the change in suPAR from baseline was associated with eGFR, but this association was not different for patients with FSGS as compared with other diagnoses. Thus these results do not support a pathological role for suPAR in FSGS.

Background: Soluble urokinase-type plasminogen activator receptor (suPAR) could be a causative factor in idiopathic focal segmental glomerulosclerosis (FSGS). It is currently unknown to what extent suPAR levels could be affected by treatment with immunosuppressive drugs such as cyclosporin A (CsA) and mycophenolate mofetil (MMF). Treatment with CsA, but not MMF, is accompanied by nephrotoxicity, and since suPAR levels correlate with glomerular filtration rate (GFR), treatment with these drugs could indirectly modulate suPAR levels by their effect on renal function., Methods: We measured suPAR levels in a recent prospective multicenter crossover trial comparing the efficacy of MMF and CsA in pediatric patients with minimal change disease (MCD) and frequently relapsing steroid-sensitive nephrotic syndrome (FR-SSNS). All patients had biopsy-proven MCD and normal renal function; they were treated with each drug for 1 year in a crossover study design. Serum suPAR levels were measured before and after 1 year of therapy with MMF (n = 40) and CsA (n = 35)., Results: The suPAR levels decreased after 1 year of treatment with MMF (p < 0.05). Conversely, suPAR levels increased after 1 year of treatment with CsA in the same patients (p = 0.01). These changes in suPAR levels were not correlated to the estimated glomerular filtration rate (eGFR) or changes in the GFR., Conclusions: Data from this prospective randomized trial suggest that treatment with MMF and CsA is associated with different effects on suPAR levels in children with MCD and that these are independent of their effects on GFR.

Background and Objectives: Soluble urokinase plasminogen activator receptor (suPAR) was initially proposed as a pathogenic and predictive biomarker of primary FSGS, but the findings were controversial. This study aimed to clarify the clinical implications of suPAR., Design, Setting, Participants, & Measurements: The study enrolled 109 patients with biopsy-proven primary FSGS who were administered prednisone between January 2011 and May 2013 and followed up for 6-24 months (median duration of follow-up, 12 months). Ninety-six healthy volunteers, 20 patients with minimal-change disease (MCD), and 22 patients with membranous nephropathy (MN) served as controls. Serum suPAR levels were measured using ELISA., Results: suPAR levels in patients with FSGS (median, 3512 [interquartile range (IQR), 2232-4231] pg/ml) were significantly higher than in healthy controls (median, 1823 [IQR, 1563-2212] pg/ml; P<0.001), patients with MCD (median, 1678 [IQR, 1476-2182] pg/ml; P<0.001), and patients with MN (median, 1668 [IQR, 1327-2127] pg/ml; P<0.001). With 3000 pg/ml used as a threshold, suPAR levels were elevated in 48.6% of patients with FSGS, in contrast to 5% of patients with MCD and 4.5% of those with MN. suPAR levels were independently associated with steroid response in patients with FSGS (odds ratio, 85.02; P=0.001). Patients who were sensitive to steroids had significantly higher suPAR levels than nonsensitive patients (median, 3426 [IQR, 2670-5655] pg/ml versus 2523 [IQR, 1977-3460] pg/ml; P=0.001). A suPAR level of 3400 pg/ml was chosen as the optimal cutoff value for steroid response. At the 6-month follow-up in 84 patients with FSGS, suPAR levels were significantly decreased in those with suPAR level ≥ 3400 pg/ml (median, 4553 [IQR, 3771-6120] pg/ml versus 3149 [IQR, 2278-3953]; P=0.002) but were unchanged in patients with suPAR level <3400 pg/ml (median, 2359 [IQR, 2023-2842] pg/ml versus 2490 [IQR, 1916-3623] pg/ml; P=0.09)., Conclusions: suPAR is specifically elevated in some patients with FSGS, which differs from the finding in patients with MCD and MN. A suPAR assay may help predict steroid response in patients with primary FSGS., (Copyright © 2014 by the American Society of Nephrology.)

Background and Objectives: Patients with IgA nephropathy typically present with hematuria and subnephrotic proteinuria. Nephrotic syndrome is uncommon in IgA nephropathy, and when present, it is usually associated with severe histologic features, such as endocapillary proliferation, segmental sclerosis, and crescent formation. Rarely, patients with IgA nephropathy present with nephrotic syndrome and only mild mesangial disease. This study sought to better characterize these patients., Design, Setting, Participants, & Measurements: A retrospective review of cases of IgA nephropathy diagnosed from 2004 to 2011 identified patients with nephrotic range proteinuria and histologically mild IgA nephropathy. Specifically, using the Oxford Classification of IgA Nephropathy, we identified cases that lacked endocapillary proliferation or segmental sclerosis., Results: The cohort consisted of 17 patients, including 10 men and 15 adults. The median serum creatinine was 0.9 mg/dl (range=0.7-3.1), median 24-hour urine protein was 8.0 g/d (3.0-18.0 g), and 14 patients were fully nephrotic, whereas the remaining 3 patients fulfilled two of three criteria for nephrotic syndrome. Biopsies revealed IgA-dominant or codominant deposits accompanied by mesangial proliferation in 14 patients (82.4%). Electron microscopy showed mesangial deposits and extensive foot process effacement (median=90%). Initial treatment consisted of corticosteroids, although many patients required additional agents to maintain remission status. Over a median follow-up of 20 months (2.2-82 months), 14 patients experienced a complete response, and 3 patients showed a partial response, with a median response time of 2 months (0.5-27 months). At least one relapse of nephrotic syndrome occurred in nine patients (53%). All patients exhibited stable or improved renal function over the follow-up period., Conclusions: The findings in this cohort and previous studies suggest that rare cases of mild IgA nephropathy with nephrotic range proteinuria exhibit a clinical presentation, biopsy findings, treatment response, and outcome more typical of IgA nephropathy with superimposed minimal change disease. This study favors the view that such cases represent a dual glomerulopathy., (Copyright © 2014 by the American Society of Nephrology.)

Elevated serum-soluble urokinase receptor (suPAR) levels have been described in patients with focal segmental glomerulosclerosis (FSGS) in several different cohorts. However, it remains unclear whether this is the case for Japanese patients and whether circulating suPAR can be clinically useful as a diagnostic marker. To determine this, we measured serum suPAR levels in 69 Japanese patients with biopsy-proven glomerular diseases in a cross-sectional manner. The serum suPAR levels showed a significant inverse correlation with renal function by univariate (R(2) of 0.242) and multivariate (β=0.226) analyses. Even after excluding patients with renal dysfunction, no significant difference in the suPAR levels was detected among the groups. Receiver operating characteristic analysis and measures of the diagnostic test performance showed that suPAR was not a useful parameter for differentiating FSGS from the other glomerular diseases (AUC-ROC: 0.621), although a small subgroup analysis showed that patients with FSGS, treated with steroids and/or immunosuppressants, had significantly lower suPAR levels. Patients with ANCA-associated glomerulonephritis had significantly higher levels of suPAR compared with the other disease groups, which may be owing to their lower renal function and systemic inflammation. Thus, suPAR levels are significantly affected by renal function and have little diagnostic value even in patients with normal renal function.

Background: T follicular helper (TFH) cells are involved in the humoral immune responses. This study is aimed at examining the frequencies of different subsets of CD4(+)CXCR5(+) TFH cells in adult patients with minimal change disease (MCD)., Methods: A total of 27 patients and 14 healthy controls (HC) were characterized for the levels of sera cytokines, inducible T-cell costimulator (ICOS), and programmed death 1 (PD-1) of positive TFH cells by flow cytometry. The level of sera IL-21 was examined; 24 h urinary protein and eGFR were calculated. The potential correlation between the frequency of different subsets of TFH cells and the values of clinical measures in MCD patients were analyzed., Results: The frequency of circulating CD4(+)CXCR5(+), CD4(+)CXCR5(+)ICOS(+), and CD4(+)CXCR5(+)PD-1(+) TFH cells and the levels of sera IL-17A, IFN-γ, IL-2, IL-10, IL-4, and IL-21 were significantly higher in MCD patients (P < 0.05) than that in the HC group. Furthermore, the percentages of circulating CD4(+)CXCR5(+) TFH cells were negatively correlated with the values of eGFR (r = -0.4849, P < 0.05) and the percentages of CD4(+)CXCR5(+)PD-1(+) TFH cells were correlated positively with the levels of serum IL-21 (r = 0.6137, P < 0.05) and 24 h urinary protein (r = 0.1410, P < 0.05) in those patients. Also, the percentages of CD4(+)CXCR5(+)ICOS(+) TFH cells were correlated positively with the levels of serum IL-21 (r = 0.6201, P < 0.05) and 24 h urinary protein (r = 0.7519, P < 0.05). Following standard therapies, the percentages of circulating CD4(+)CXCR5(+), CD4(+)CXCR5(+)PD-1(+), and CD4(+)CXCR5(+)ICOS(+) TFH cells and the levels of serum IL-21 were significantly reduced, but the levels of serum IL-4 and IL-10 were increased (P < 0.05)., Conclusions: A higher frequency of CD4(+)CXCR5(+) TFH cells that existed in adult patients with MCD could be new target for intervention of MCD.

Background: Minimal change disease (MCD) is the most common cause of nephrotic syndrome in children and is associated with the expression of CD80 in podocytes and the increased excretion of CD80 in urine. We hypothesized that serum from patients with MCD might stimulate CD80 expression in cultured podocytes., Methods: Sera and peripheral blood mononuclear cells (PBMCs) were collected from subjects with MCD in relapse and remission and from normal controls. Immortalized human podocytes were incubated with culture media containing patient sera or supernatants from patient and control PBMC cultures. CD80 expression was measured by quantitative PCR and western blot analysis., Results: Sera collected from patients with MCD in relapse, but not in remission, significantly increased CD80 expression (mean ± standard deviation: 1.8 ± 0.7 vs. 0.8 ± 0.2; p < 0.004) and CD80 protein secretion by podocytes (p < 0.05 between relapse and normal controls). No such CD80 increase was observed when podocytes were incubated with supernatants of PBMC cultures from patients in relapse., Conclusions: Sera from MCD patients in relapse, but not in remission, stimulated CD80 expression in cultured podocytes. Identifying this factor in sera could provide insights into the pathogenesis of this disorder. No role in CD80 expression by podocytes was found for cytokines released by PBMCs.

Background: Minimal-change nephrotic syndrome is an idiopathic disease in which protein leaks through podocytes into the urine. We used proteomic tools to examine differences of plasma protein expression in healthy rats and rats with doxorubicin-induced nephropathy treated with or without prednisone., Methods: Healthy three-month-old Sprague-Dawley male rats were randomly chosen for one injection of doxorubicin (5.5 mg/kg) through the caudal vein to induce nephropathy (n = 50) or the same volume of saline (control, n = 20). After 1 week, 25 rats in the nephropathy group received topical prednisone (5.5 mg/kg/day) for 21 days and another 25 rats (untreated nephropathy) and the control rats received topical water. At 4 weeks, protein chips generated from rat plasma samples were analyzed by surface enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS) to obtain mass-to-charge ratios (m/z) of proteins of 2-50 kDa., Results: Relative to control rats, untreated nephropathic rats had four significantly higher and seven significantly lower m/z peaks. Prednisone treatment significantly normalized the intensities of peaks 9069 and 15005 (which correspond to cortexin-1 and interleukin-17A, respectively, according to Swiss Prot database) by increasing the expression of 9069 but reducing expression of 15005., Conclusion: Significant differences in plasma proteins can be identified by proteomic analysis using SELDI-TOF-MS in a rat model of nephropathy.

The bisalbuminemia acquired outside of the long-term antibiotic treatment is an exceptional event. It is a rare condition characterised by the presence of two distinct fractions of serum albumin on electrophoresis. This anomaly reflects the presence, at the same time, of a normal albumin and a modified albumin. These changes of albumin may be related to various causes. Their association with nephrotic syndrome is exceptional. We report a case of bisalbuminemia during a period of remission of nephrotic syndrome.

Introduction: This study assessed the role of procalcitonin (PCT) in the differentiation of minimal-change nephropathy (MCN) relapses from infections co-existent with proteinuria flares in children., Methods: Data on the PCT levels of patients with MCN who were on follow-up were retrospectively gathered at relapse (Group I), during proteinuria attacks co-existent with intercurrent infection (Group II) and at remission (Group III). The results of these three groups were then prospectively compared with nephrologically healthy patients who had infections that were similar to those in Group II (Group IV), and controls (Group V)., Results: Significant differences in PCT level were noted between patients of Groups I, II and IV and the other two groups. A 93% reduction in proteinuria was achieved for Group II patients following an antibiotic regimen. The difference in PCT level between Groups I and II was significant. PCT showed a higher diagnostic predictability than C-reactive protein (CRP) in Group I patients, and was as good as CRP for those with infection and infection-related proteinuria. Sensitivity × specificity in relapse and infection-related states for PCT were 0.472 and 0.628, respectively, and those for CRP were 0.183 and 0.762, respectively., Conclusion: A combined approach with CRP and PCT readings may be beneficial in discriminating proteinuria attacks co-existent with intercurrent infection from sole relapses of nephrotic syndrome. PCT may be a part of the wide spectrum of immune abnormalities seen in patients with MCN.

Recent studies showed that an imbalance of prothrombotic and antithrombotic factors and impaired thrombolytic activity contribute to the thrombophilia of the nephrotic syndrome (NS). However, it is not clear whether blood cell injury and/or activation is involved in hypercoagulability in NS patients. Our objectives were to study the increase in microparticle (MP) release and phosphatidylserine (PS) exposure on the outer membrane of MP-origin cells in NS patients, and to evaluate their procoagulant activity (PCA). The subjects were patients with membranous nephropathy (MN), minimal change nephrotic syndrome (MCNS) and healthy controls. Analyses of MPs and PS exposure were performed using a flow cytometer. PCA was determined by clotting time and purified coagulation complex assays. We found that lactadherin+ MPs, which derived from red blood cells (RBC), platelet and endothelial cell, increased in NS patients. Moreover, PS exposure on RBCs and platelets in each NS group, especially in MN, are higher than that in controls. MP shedding and PS exposure of RBCs/platelets were highly procoagulant in NS patients. However, blockade of PS with lactadherin inhibited over 90% of PCA while an anti-tissue factor antibody had no significant inhibition effect. Our results demonstrate that the thrombophilic susceptibility of NS may be partly ascribed to MP release and PS exposure of RBCs, platelets and endothelial cells. Lactadherin is a sensitive probe for PS that has high anticoagulant activity.

Aims: To further elucidate the clinical relevance of T-cell abnormalities in minimal change nephrotic syndrome (MCNS), and to predict the consequences of MCNS, we studied T-cell receptor (TCR) diversity by analyzing CDR3 size distribution and the frequency of Vβ repertoire usage., Methods: Participants comprised 36 pediatric patients with MCNS. 18 were frequent relapsers (FRs) and/or steroid-dependent (SD) and 18 were non-frequent relapsers (NFRs). Serial changes in TCR Vβ repertoires were analyzed for these two groups of patients. Frequencies of Vβ repertoire usage were determined by flow cytometry, and TCR CDR3 length distribution was analyzed by GeneScan., Results: In NFRs, abnormalities in the distribution of Vβ repertoires were few in both CD4+ and CD8+ T cells. In FRs/ SD patients, patterns were normal in CD4+ T cells, while selected Vβ repertoires were significantly increased in CD8+ T cells in some patients. Furthermore, TCR diversity was significantly reduced in CD8+ T cells in FRs/SD patients, as shown by marked skewing of CDR3 size distributions. Of note was the finding that some FRs/SD patients showed improvements in the initially abnormal TCR diversity with improvement in clinical symptoms, eventually becoming NFRs., Conclusion: Analysis of TCR diversity may delineate the subgroup of FRs/SD patients and provide a rationale for early intervention with immunosuppressive therapy for these patients.

Introduction: Imbalance between T-helper 1 (Th1) and 2 (Th2) lymphocytes and effects of reactive oxygen species (ROS) upon glomerular capillary walls have been implicated in minimal change nephrotic syndrome (MCNS)., Methods: By polymerase chain reaction and comparative genomic hybridization, we evaluated mutations of the GSTT1 gene (GSTT1), a member of the glutathione S-transferase (GST) supergene family associated with both protection of cells from ROS and control of allergic reactions and serum immunoglobulin (Ig) E., Results: Among 15 children with MCNS, IgE elevation (over 2,000 IU/l) and GSTT1 deletion was found in 2 who showed severe allergic symptoms. Serum ROS concentrations in these 2 patients were significantly higher than in healthy controls or other MCNS patients. In addition, a Th2 shift caused by increased serum interleukin (IL)- 4 was observed., Conclusion: These results suggest presence of a GSTT1 abnormality in some children with MCNS having marked serum IgE elevations and various allergic complications. Defective ROS degradation and Th1/Th2 imbalance caused by GSTT1 abnormality could initiate proteinuria leading to MCNS.

To determine whether Th17/Treg balance was abnormal in adult patients with minimal change nephrotic syndrome (MCNS), we studied 25 patients with new-onset MCNS and 20 normal persons. The results showed that MCNS patients exhibited a significant increase in Th17 number, Th17-related cytokines (IL-17 and IL-23), and transcription factor (RORγt) levels, as well as an obvious decrease in Treg number, Treg-related cytokines (TGF-β1 and IL-10), and transcription factor (Foxp3) levels. The Th17/Treg ratios increased along with increased proteinuria and decreased albumin levels in patients with MCNS. IL-17 protein expression was also detected in the renal biopsy tissue of MCNS patients, particularly in patients with acute renal failure. Further, Th17/Treg balance returned to normal after effective corticosteroids therapy in 16 MCNS patients. These results indicated that Th17/Treg imbalance existed in MCNS patients, suggesting a potential role of Th17/Treg imbalance in the pathogenesis of MCNS., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Resistance to glucocorticoid (GC) treatment is a significant clinical problem in many diseases. Most effects of GC are mediated by glucocorticoid receptor (GR). Multiple promoters have been found in GR gene, which results in different exons 1 s. In human leukemia cell lines, GC response is thought to be related with promoter usage and auto-upregulation of GR. In this study, we investigated whether GR could be auto-induced in peripheral blood mononuclear cells (PBMCs) and whether an inability to upregulate the GR is related with GC resistance in idiopathic nephrotic syndrome (INS)., Methods: Reverse transcription-PCR was applied to measure the mRNA expression of GR transcripts (GR exons 1A, 1B, 1C, and GR), and real-time PCR was used to confirm these results. GR protein expression was analyzed by Western blot., Results: Following GC treatment, both GR exon 1A and GR in PBMCs were increased in vitro, while GR exons 1B and 1C showed no significant changes. In patients with INS, the glucocorticoid-sensitive group expressed more GR exon 1A and less GR exon 1C than the glucocorticoid-resistant group, but the total GR showed no significant difference., Conclusions: GR is auto-induced in PBMCs in vitro and GR promoter 1A is involved in this mechanism; however the auto-upregulation of GR is not related with glucocorticoid response in patients with INS.

Immunoglobulin E (IgE) antibodies may play a role in the development of kidney diseases that are related to hypersensitivity reactions. Patients with idiopathic nephrotic syndrome often exhibit increased serum IgE levels and this may be related to sensitivity to steroid treatment. In the present study, the serum IgE levels in 120 patients with different types of primary nephrotic syndrome (PNS) were analysed and found to be significantly elevated in cases of minimal change nephrotic syndrome (MCNS) compared with membranous nephropathy or membrano-proliferative glomerulonephritis. No difference in serum IgE level was observed between cases of steroid-sensitive nephrotic syndrome (SSNS) or steroid-resistant nephrotic syndrome, although the serum IgE level was significantly elevated in SSNS patients in relapse compared with SSNS patients in remission. In MCNS patients, 73.6% exhibited SSNS regardless of their serum IgE level at diagnosis. It is concluded that elevated levels of IgE may be a feature of steroid resistance or relapse, indicating prognostic significance in adult PNS, particularly in MCNS.