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The goal of this study is to identify systematic biomarker panel for primary nephrotic syndromes from urine samples by applying a non-target metabolite profiling, and to validate their utility in independent sampling and analysis by multiplex statistical approaches. Nephrotic syndrome (NS) is a nonspecific kidney disorder, which is mostly represented by minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), and membranous glomerulonephritis (MGN). Since urine metabolites may mirror disease-specific functional perturbations in kidney injury, we examined urine samples for distinctive metabolic changes to identify biomarkers for clinical applications. We developed unbiased multi-component covarianced models from a discovery set with 48 samples (12 healthy controls, 12 MCD, 12 FSGS, and 12 MGN). To extensively validate their diagnostic potential, new batch from 54 patients with primary NS were independently examined a year after. In the independent validation set, the model including citric acid, pyruvic acid, fructose, ethanolamine, and cysteine effectively discriminated each NS using receiver operating characteristic (ROC) analysis except MCD-MGN comparison; nonetheless an additional metabolite multi-composite greatly improved the discrimination power between MCD and MGN. Finally, we proposed the re-constructed metabolic network distinctively dysregulated by the different NSs that may deepen comprehensive understanding of the disease mechanistic, and help the enhanced identification of NS and therapeutic plans for future., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Purpose: After observing variation in the expression of the housekeeping gene B2M in cells of the urinary sediment during a study of candidate genes potentially involved in diabetic kidney disease (DKD), we hypothesized that B2M mRNA expression in the urinary sediment could reflect the presence of DKD., Methods: qPCR was used to quantify B2M mRNA expression in cells of the urinary sediment of 51 type 1 diabetes (T1D) patients (61% women, 33.5 [27.0-39.7] years old, with diabetes duration of 21.0 [15.0-28.0] years and HbA1c of 8.2% [7.3-8.9]; median [interquartile interval]) sorted according to the diabetic nephropathy (DN) stages; 8 focal segmental glomerulosclerosis (FSGS) patients and 10 healthy controls. B2M mRNA expression was also evaluated in human embryonic kidney epithelium-like (HEK-293) cells exposed to 25mM glucose and to albumin in order to mimic, respectively, a diabetic and a proteinuric milieu., Results: No differences were found in B2M mRNA expression among healthy controls, FSGS and T1D patients. Nonetheless B2M mRNA expression was higher in the group composed by T1D patients with incipient or overt DN combined with FSGS patients versus T1D patients without DN combined with healthy controls (P=0.0007). B2M mRNA expression was higher in T1D patients with incipient or overt DN versus without DN (P=0.03). B2M mRNA expression positively correlated with albuminuria in the overall T1D population (r=0.43; P=0.01) and negatively correlated with estimated glomerular filtration rate in male T1D patients (r=- 0.57; P=0.01). Increased B2M expression was observed in HEK-293 cells exposed to 25mM glucose and to albumin., Conclusions: Β2M mRNA expression in cells of the urinary sediment is higher in T1D patients with DKD and in patients with FSGS in comparison to healthy subjects, maybe reflecting a tubulointerstitial injury promoted by albumin. Given the proinflammatory nature of B2M, we suggest that this protein contributes to diabetic (and possibly, to non-diabetic) tubulopathy., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Focal segmental glomerulosclerosis (FSGS) accounts for the majority of new-onset end-stage renal disease (ESRD) during adolescence. FSGS treatment is a great challenge for pediatric nephrologists due to intertwined molecular pathways underlining its complex pathophysiology. There is emerging evidence showing that perturbed lipid metabolism plays a role in the pathophysiology of FSGS., Methods: We postulate that the nephrotic milieu in FSGS differs from minimal change disease (MCD) and that urinary lipidomics can be used as a tool for early diagnosis of FSGS. We explored the urinary lipid profile of patients with FSGS and MCD using an unbiased metabolomics approach., Results: We discovered a unique lipid signature characterized by increased concentration of fatty acid (FA) and lysophosphatidylcholines (LPC) and a decrease in urinary concentration of phosphatidylcholine (PC) in patients with FSGS. These findings indicate increased metabolism of membrane phospholipid PC by phospholipase A2 (PLA2), resulting in higher urinary concentrations of LPC and FA., Conclusions: We propose that increased PC by-products can be used as a biomarker to diagnose FSGS and shed light on the mechanism of tubular and podocyte damage. Validation of identified urinary lipids as a biomarker in predicting the diagnosis and progression of FSGS in a larger patient population is warranted.

Urinary microvesicles constitute a rich source of membrane-bound and intracellular proteins that may provide important clues of pathophysiological mechanisms in renal disease. In the current study, we analyzed and compared the proteome of urinary microvesicles from patients with idiopathic membranous nephropathy (iMN), idiopathic focal segmental glomerulosclerosis (iFSGS), and normal controls using an approach that combined both proteomics and pathology analysis. Lysosome membrane protein-2 (LIMP-2) was increased greater than twofold in urinary microvesicles obtained from patients with iMN compared to microvesicles of patients with iFSGS and normal controls. Immunofluorescence analysis of renal biopsies confirmed our proteomics findings that LIMP-2 was upregulated in glomeruli from patients with iMN but not in glomeruli of diseased patients (iFSGS, minimal change nephropathy, IgA nephropathy, membranoproliferative glomerulonephritis) and normal controls. Confocal laser microscopy showed co-localization of LIMP-2 with IgG along the glomerular basement membrane. Serum antibodies against LIMP-2 could not be detected. In conclusion, our data show the value of urinary microvesicles in biomarker discovery and provide evidence for de novo expression of LIMP-2 in glomeruli of patients with iMN., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Podocyte depletion is a characteristic feature of progressive renal failure. We hypothesize that studying the podocyte mRNA level in urinary sediment may provide diagnostic and prognostic information in adult nephrotic syndrome., Methods: We studied 25 patients with minimal change nephropathy (MCN), 25 with focal segmental glomerulosclerosis (FSGS), and 17 healthy controls. The mRNA levels of nephrin, podocin, and synaptopodin in urinary sediment were quantified., Results: There were significant differences in the urinary sediment nephrin and podocin, but not synaptopodin, mRNA levels between diagnosis groups. Post-hoc analysis further showed that urinary nephrin mRNA levels of the MCN group were lower than those in the control and FSGS groups, although the difference between MCN and FSGS groups did not reach statistical significance. The degree of proteinuria inversely correlated with urinary nephrin mRNA levels in the MCN (r = -0.526, p = 0.007) as well as in the FSGS group (r = -0.521, p = 0.008). For the FSGS group, the rate of renal function decline significantly correlated with baseline urinary synaptopodin mRNA levels (r = -0.496, p = 0.012)., Conclusions: Urinary nephrin and podocin mRNA levels were reduced in patients with MCN and probably FSGS, and the magnitude of reduction correlated with the degree of proteinuria. Urinary synaptopodin mRNA levels correlated with the subsequent rate of renal function decline in patients with FSGS. Our result indicates that urine sediment podocyte mRNA levels provide novel insights in the pathophysiology of nephrotic syndrome and could be useful for risk stratification.

Background: Recent pre-clinical studies have shown that complement activation contributes to glomerular and tubular injury in experimental FSGS. Although complement proteins are detected in the glomeruli of some patients with FSGS, it is not known whether this is due to complement activation or whether the proteins are simply trapped in sclerotic glomeruli. We measured complement activation fragments in the plasma and urine of patients with primary FSGS to determine whether complement activation is part of the disease process., Study Design: Plasma and urine samples from patients with biopsy-proven FSGS who participated in the FSGS Clinical Trial were analyzed., Setting and Participants: We identified 19 patients for whom samples were available from weeks 0, 26, 52 and 78. The results for these FSGS patients were compared to results in samples from 10 healthy controls, 10 patients with chronic kidney disease (CKD), 20 patients with vasculitis, and 23 patients with lupus nephritis., Outcomes: Longitudinal control of proteinuria and estimated glomerular filtration rate (eGFR)., Measurements: Levels of the complement fragments Ba, Bb, C4a, and sC5b-9 in plasma and urine., Results: Plasma and urine Ba, C4a, sC5b-9 were significantly higher in FSGS patients at the time of diagnosis than in the control groups. Plasma Ba levels inversely correlated with the eGFR at the time of diagnosis and at the end of the study. Plasma and urine Ba levels at the end of the study positively correlated with the level of proteinuria, the primary outcome of the study., Limitations: Limited number of patients with samples from all time-points., Conclusions: The complement system is activated in patients with primary FSGS, and elevated levels of plasma Ba correlate with more severe disease. Measurement of complement fragments may identify a subset of patients in whom the complement system is activated. Further investigations are needed to confirm our findings and to determine the prognostic significance of complement activation in patients with FSGS.

Dogue de Bordeaux dog has been reported to be predisposed to a familial glomerulonephropathy that displays some morphological modifications reported in focal and segmental glomerulosclerosis. Prevalence of quantitatively abnormal renal proteinuria was recently reported to be 33% in this breed. The nature of the proteinuria was assessed by sodium dodecyl sulfate-agarose gel electrophoresis and determinations of urinary markers (urinary retinol-binding protein, urinary N-acetyl-β-glucosaminidase, urinary albumin and urinary immunoglobulin G) on stored specimens. Diagnostic performances of sodium dodecyl sulfate-agarose gel electrophoresis to identify dogs with elevated urinary biomarkers were assessed. Samples from 102 adult Dogue de Bordeaux dogs (47 non-proteinuric [urine protein-to-creatinine ratio ≤ 0.2], 20 borderline-proteinuric [0.2< urine protein-to-creatinine ratio ≤ 0.5] and 35 proteinuric dogs [urine protein-to-creatinine ratio >0.5]) were used, of which 2 were suffering from familial glomerulonephropathy. The electrophoretic protein patterns, for all but one proteinuric dog, were indicative of a glomerular origin and, in all dogs, the urinary albumin concentration related to creatinine concentration and the urinary immunoglobulin G concentration related to creatinine concentration were above the upper limit of the reference interval established for the breed. Sensitivity and specificity of sodium dodecyl sulfate-agarose gel electrophoresis identifying dogs with elevated urinary albumin concentration were 94% and 92%, respectively, while diagnostic performance of sodium dodecyl sulfate-agarose gel electrophoresis in detecting dogs with elevated urinary immunoglobulin G concentration yielded sensitivity and specificity of 90% and 74%, respectively. These results suggest that all proteinuric and some borderline-proteinuric Dogue de Bordeaux dogs likely have underlying glomerular lesions and that sodium dodecyl sulfate-agarose gel electrophoresis and urinary markers might be useful to screen dogs with borderline-proteinuria. Additional investigations are warranted to assess if these findings are related to the familial glomerulonephropathy.

Background: This study aimed to describe the influences of larger physical constitutions including obesity on the amount of urine protein excretion (AUPE) in primary glomerulonephritis. The distinct effects on the AUPE in various types of glomerulonephritis were evaluated., Methods: Using the database of the Japan Renal Biopsy Registry (J-RBR) from 2007 to 2010, 4060 cases with primary glomerulonephritis including MCNS, FSGS, MN, MPGN, IgAN, and non-IgA were reviewed. The AUPEs were compared between high and low Body Mass Index (BMI) groups, and larger and smaller body surface area (BSA) groups using the indexes of BMI 25.0 kg/m(2) and BSA 1.73 m(2) in all cases and in each histological group. Multivariable analysis was performed to evaluate the predominant contributors to the AUPE., Results: The larger physical constitution groups (BMI ≥25.0 kg/m(2) or BSA ≥1.73 m(2)) had significantly higher AUPEs in all cases with primary glomerulonephritis. When compared in each histological group, the mean AUPEs were significantly higher in the larger physical constitution groups, excluding the FSGS and non-IgA groups. Multiple regression analysis revealed that the significant contributors to the AUPE were BMI and BSA in MCNS and MN, whereas BMI and BSA were not significant and mean blood pressure and serum creatinine were significant in FSGS and non-IgA., Conclusion: Larger physical constitutions including obesity had a significant impact on the increase in the AUPE in primary glomerulonephritis, especially in MCNS and MN. However, FSGS and non-IgA were distinct for having blood pressure and renal dysfunction as possibly the major causes of proteinuria.

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: Minimal Change Disease (MCD) in relapse is associated with increased podocyte CD80 expression and elevated urinary CD80 excretion, whereas focal segmental glomerulosclerosis (FSGS) has mild or absent CD80 podocyte expression and normal urinary CD80 excretion., Methods: One patient with MCD, one patient with primary FSGS and three patients with recurrent FSGS after transplantation received CD80 blocking antibodies (abatacept or belatacept). Urinary CD80 and CTLA-4 levels were measured by ELISA. Glomeruli were stained for CD80., Results: After abatacept therapy, urinary CD80 became undetectable with a concomitant transient resolution of proteinuria in the MCD patient. In contrast, proteinuria remained unchanged after abatacept or belatacept therapy in the one patient with primary FSGS and in two of the three patients with recurrent FSGS despite the presence of mild CD80 glomerular expression but normal urinary CD80 excretion. The third patient with recurrent FSGS after transplantation had elevated urinary CD80 excretion immediately after surgery which fell spontaneously before the initiation of abatacept therapy; after abatacept therapy, his proteinuria remained unchanged for 5 days despite normal urinary CD80 excretion., Conclusion: These observations are consistent with a role of podocyte CD80 in the development of proteinuria in MCD. In contrast, CD80 may not play a role in recurrent FSGS since the urinary CD80 of our three patients with recurrent FSGS was only increased transiently after surgery and normalization of urinary CD80 did not result in resolution of proteinuria.

Background/aims: A link between the number of podocytes excreted in the urine and activity of glomerular disease has been established. The aim of this study was to investigate possible correlations between urinary cells' phenotype and the progression of focal segmental glomerulosclerosis (FSGS)., Methods: Forty patients with newly diagnosed FSGS were included. Cells were isolated from urine by adherence to collagen-coated cover slips and assessed for the expression of podocalyxin (PDX), CD68 and Ki67 antigens by indirect immunofluorescence. In addition, double-staining procedures were performed in combinations of the above antigens plus cytokeratin, WT1 and CD-105. Twenty-two patients in whom urinary protein to creatinine ratio exceeded 2.0 at diagnosis were followed for 36 months, with assessments of renal function and proteinuria every 3 months. During observation, patients were subjected to standard therapy., Results: Significantly higher numbers of Ki67 positive cells at the onset of the study were observed in patients who have doubled serum creatinine (SCr) in follow-up, than in those who have not (p = 0.0149). By logistic regression analysis, both CD68 and Ki67, but not anti-PDX positive cell numbers at diagnosis were found to be predictors of doubling SCr concentration in 36 months' follow-up. Results of double staining indicate that PDX positive cells could be identified as podocytes or their precursors and parietal epithelial cells., Conclusion: Urinary sediment PDX positive cell numbers do not predict the progression of FSGS, whereas CD68 and Ki67 phenotype of urinary podocytic lineage clearly has a prognostic significance in 36 months' observation of primary FSGS., (© 2015 S. Karger AG, Basel)

Compare to blood, which has mechanisms to maintain homeostasis, urine is more likely to reflect changes in the body. As urine accumulates all types of changes, identifying the precise cause of changes in the urine proteome is challenging and crucial in biomarker discovery. To reduce the confounding factors to minimal, some studies used animal model resembling human diseases. This chapter highlights the importance of animal models and introduces a strategic research which focused on adriamycin-induced nephropathy. In this study, urine samples were collected at before adriamycin administration and days 3, 7, 11, 15, and 23 after, urinary proteins were profiled by LC-MS/MS. Of 23 changed proteins with disease development, 13 proteins were identified as stable in normal human urine, meaning that changes in these proteins are more likely to reflect disease. We think this stage-dependent dynamic changes of urine proteome in animal models will help to support the role of urine as key source in biomarker discovery especially in kidney diseases and help to identify corresponding biomarkers for clinical validation.

Recent studies have indicated that the detection of urinary podocytes holds major significance for focal segmental glomerulosclerosis (FSGS). We present two cases of FSGS after kidney transplantation, focusing on urinary podocytes. In Case 1, treatment led to incomplete remission with the reduction of urinary podocytes, and his renal function was preserved. Case 2, however, showed continuous increase in proteinuria with loss of renal function despite apheresis. Urinary podocytes remained high throughout. On the basis of this experience, we suggest the significance of the detection of urinary podocytes for determining renal prognosis in FSGS following renal allograft.

Background and Objectives: This study aimed to identify urinary microRNAs (miRNAs) as biomarkers for FSGS disease activity., Design, Setting, Participants, & Measurements: Candidate urinary miRNAs were identified in pooled urine samples from patients with active FSGS (FSGS-A) and FSGS in remission (FSGS-CR), and were then validated using individual samples. Their levels were compared both under different treatment responses in a prospective study of FSGS and in patients with different membranous nephropathy (MN) and diabetic nephropathy (DN) disease activity. The prediction of these miRNAs for treatment responses was further analyzed in both retrospective and prospective cohorts of patients with FSGS., Results: All 54 miRNAs were included as candidate biomarkers, including those with high levels in patients with FSGS-A (n=9) under the TaqMan Low Density Array as well as those with conserved expression in kidneys and involved in immune response. TaqMan probe-based quantitative RT-PCR confirmed the higher levels of four miRNAs in patients with FSGS-A in two independent cohorts (n=18 and n=80). Urinary miR-196a, miR-30a-5p, and miR-490 discriminated FSGS-A from FSGS-CR, with an area under the curve of ≥ 0.80. After steroid treatment, their levels were lower in steroid-responsive patients with FSGS (all P<0.001), but were unchanged in steroid-resistant patients. The levels of miRNAs were similar between active MN and MN in remission as well as active DN and incipient DN (all P>0.05). Urinary miR-30a-5p marginally predicted the response to steroid treatment in patients with FSGS-A, with an area under the curve of 0.63 (P=0.03)., Conclusions: The levels of urinary miR-196a, miR-30a-5p, and miR-490 are associated with FSGS disease activity., (Copyright © 2014 by the American Society of Nephrology.)

Background: Focal segmental glomerulosclerosis (FSGS) is a glomerular scarring disease diagnosed mostly by kidney biopsy. Since there is currently no diagnostic test that can accurately predict steroid responsiveness in FSGS, prediction of the responsiveness of patients to steroid therapy with noninvasive means has become a critical issue. In the present study urinary proteomics was used as a noninvasive tool to discover potential predictive biomarkers., Methods: Urinary proteome of 10 patients (n = 6 steroid-sensitive, n = 4 steroid-resistant) with biopsy proven FSGS was analyzed using nano-LC-MS/MS and supervised multivariate statistical analysis was performed., Results: Twenty one proteins were identified as discriminating species among which apolipoprotein A-1 and Matrix-remodeling protein 8 had the most drastic fold changes being over- and underrepresented, respectively, in steroid sensitive compared to steroid resistant urine samples. Gene ontology enrichment analysis revealed acute inflammatory response as the dominant biological process., Conclusion: The obtained results suggest a panel of predictive biomarkers for FSGS. Proteins involved in the inflammatory response are shown to be implicated in the responsiveness. As a tool for biomarker discovery, urinary proteomics is especially fruitful in the area of prediction of responsiveness to drugs. Further validation of these biomarkers is however needed.

Background: Minimal change disease (MCD) is characterized by increased urinary excretion of CD80, whereas focal segmental glomerulosclerosis (FSGS) is associated with increased serum soluble urokinase-type plasminogen activator receptor (suPAR). The aim of the study was to assess whether the simultaneous measurement of urinary CD80 and serum suPAR helps differentiate MCD and FSGS., Methods: Urine and sera were collected from patients with MCD in relapse or in remission, from FSGS patients with nephrotic syndrome, and from healthy individuals. CD80 and suPAR were measured by ELISA., Results: Urinary CD80 was significantly increased in MCD patients in relapse compared with those in remission and with FSGS patients and control individuals. Serum suPAR levels were significantly higher in patients with FSGS when compared with MCD patients in relapse. Urinary suPAR showed a positive correlation with proteinuria in MCD in relapse and FSGS patients, whereas urinary CD80 correlated with proteinuria only in MCD patients in relapse., Conclusion: Urinary CD80 is elevated in MCD patients in relapse compared with FSGS patients. In contrast, serum suPAR is significantly elevated in FSGS patients. The consistent pattern of these two biomarkers in MCD and FSGS suggests that these two conditions represent different entities rather than a continuum spectrum of one disease.

Steroid-resistant nephrotic syndrome (SRNS) patients are candidates for other alter-native drug regimes, and the non-responsiveness to steroid is more common among glomerulo-nephritides other than minimal change disease. Without performing biopsy and proper renal histology, progression of the disease cannot be assessed. Fractional excretion of magnesium (FE Mg) has been found to correlate directly with various renal histologies. The aim of this study is to evaluate the relationship of FE Mg in children with the histological pattern in SRNS. In this prospective observational study, 40 children of nephrotic syndrome, both with the first episode as well as relapse, aged 1-12 years were included in the study. Of them, 20 were steroid-responsive cases and 20 were steroid-resistant cases. FE Mg was determined in all the patients and renal histology was performed in the steroid-resistant cases. A correlation was found between FE Mg and renal histology. Data were analyzed in SPSS program version-16. Comparison of two groups was performed by the Fisher exact test and unpaired t test. P-value less than 0.05 were considered to be significant. The results of histo-pathology showed that the mean difference in FE Mg was significant (P <0.001), as FE Mg was 7.0 ± 2.3% in mesangiocapillary glomerulonephritis, 6.9 ± 1.3% in focal segmental glomerulosclerosis, 4.7 ± 0.6% in immunoglobulin M nephropathy, 4.5 ± 1.2% in focal segmental proliferative glomerulo-nephritis, 4.4 ± 1.6% in minimal change disease, 4.2 ± 0.4% in diffuse mesangial proliferative glome-rulonephritis and 3.8 ± 1.3% in mesangial proliferative glomerulonephritis. There was a statistically significant difference between FE Mg in steroid-resistant nephrotic syndrome (4.9 ± 1.9) and steroid-responsive syndrome (1.2 ± 0.3). FE Mg is a simple, minimally invasive screening marker for SRNS, and is an early predictor of clinical outcome. It can be considered as an initial investigation where biopsy cannot be performed or indications are not clear.

Background: Focal segmental glomerulosclerosis (FSGS) is a major cause of end-stage renal disease. Recent studies have proposed that plasma soluble urokinase receptor (suPAR) might be a causative circulating factor but this proposal has caused controversy. This study aimed to measure urinary suPAR levels in patients with primary FSGS and its significance in the pathogenesis of FSGS., Methods: Sixty-two patients with primary FSGS, diagnosed between January 2006 and January 2012, with complete clinical and pathologic data were enrolled, together with disease and normal controls. Urinary suPAR levels were measured using commercial ELISA kits and were corrected by urinary creatinine (Cr). The associations between urinary suPAR levels and clinical data at presentation and during follow up were analyzed. Conditionally immortalized human podocytes were used to study the effect of urinary suPAR on activating β3 integrin detected by AP5 staining., Results: The urinary suPAR level of patients with primary FSGS (500.56, IQR 262.78 to 1,059.44 pg/μmol Cr) was significantly higher than that of patients with minimal change disease (307.86, IQR 216.54 to 480.18 pg/μmol Cr, P = 0.033), membranous nephropathy (250.23, IQR 170.37 to 357.59 pg/μmol Cr, P <0.001), secondary FSGS (220.45, IQR 149.38 to 335.54 pg/μmol Cr, P <0.001) and normal subjects (183.59, IQR 103.92 to 228.78 pg/μmol Cr, P <0.001). The urinary suPAR level of patients with cellular variant was significantly higher than that of patients with tip variant. The urinary suPAR level in the patients with primary FSGS was positively correlated with 24-hour urine protein (r = 0.287, P = 0.024). During follow up, the urinary suPAR level of patients with complete remission decreased significantly (661.19, IQR 224.32 to 1,115.29 pg/μmol Cr versus 217.68, IQR 121.77 to 415.55 pg/μmol Cr, P = 0.017). The AP5 signal was strongly induced along the cell membrane when human differentiated podocytes were incubated with the urine of patients with FSGS at presentation, and the signal could be reduced by a blocking antibody specific to uPAR., Conclusions: Urinary suPAR was specifically elevated in patients with primary FSGS and was associated with disease severity. The elevated urinary suPAR could activate β3 integrin on human podocytes.

Recurrence of focal segmental glomerulosclerosis (FSGS) is a major therapeutic challenge in kidney transplantation (KT). Although intensive plasmapheresis and high-dose rituximab have been introduced to treat recurrent FSGS, the most effective dosage and regimen of rituximab have not been determined. Herein we reported the first case of successful treatment of recurrent FSGS with a low-dose rituximab. The patient showed marked proteinuria (3.5 g/d) and oliguria 2 d after KT. Two courses of plasmapheresis and immunoglobulin were applied to the patient, however, nephrotic range proteinuria persisted and creatinine level increased to 3.56 mg/dL. Five months post-transplant, the patient received injection with only one dose of rituximab 100 mg, without further plasmapheresis, which resulted in immediate reduction of serum creatinine and full remission of proteinuria during the following 18 months. This case suggested that recurrent FSGS, which frequently relapses after plasmapheresis, could be treated successfully with a low-dose rituximab even without plasmapheresis.

Aim: The aim of the present study was to assess whether laboratory investigations have predictional values for histopathological diagnosis of glomerulonephritis before performing renal biopsy., Methods: The study enrolled 452 patients, who underwent kidney biopsy and were examined retrospectively; 128 patients with the histopathological diagnosis of glomerulonephritis were included in the study. Serum CRP, albumin, uric acid levels, 24 hour urine protein presence, leucocyte count, C3, C4, IgG, IgA and IgM levels were assessed., Results: The most common diagnosis of glomerulonephritis was IgAN with the percentage of 29.7% within the groups. Male gender was predominant except lupus group. Only the ones with crescentic glomerulonephritis had higher CRP levels. In 20% of patients with IgAN, in 8.3% of the ones with MN, in 35% of crescentic group, in 42% of FSGS group, in 30% of patients with MPGN and in 33% of the ones with lupus nephritis uric acid levels were found as elevated. In IgAN, FSGS and lupus nephritis normoalbuminemia and nephritic proteinuria, in MN and crescentic glomerulonephritis hypoalbuminemia, nephrotic proteinuria, in MPGN hypoalbuminemia, nephritic proteinuria were established. Serum Ig G levels were lower in MN and MPGN. Serum IgA levels were found as elevated in IgAN. Serum C4 levels were found as lower in lupus nephritis and MPGN., Conclusion: In patients admitted in clinical picture of glomerulopathy, since measurements of serum CRP, albumin, uric acid, C3, C4,IgG, IgA, IgM levels, leucocyte count and 24 hour urine protein amount can lead to predict the histopathological diagnosis, their significance in routine investigations has been suggested also in our study.

Model systems demonstrate that progression to ESRD is driven by progressive podocyte depletion (the podocyte depletion hypothesis) and can be noninvasively monitored through measurement of urine pellet podocyte mRNAs. To test these concepts in humans, we analyzed urine pellet mRNAs from 358 adult and pediatric kidney clinic patients and 291 controls (n=1143 samples). Compared with controls, urine podocyte mRNAs increased 79-fold (P<0.001) in patients with biopsy-proven glomerular disease and a 50% decrease in kidney function or progression to ESRD. An independent cohort of patients with Alport syndrome had a 23-fold increase in urinary podocyte mRNAs (P<0.001 compared with controls). Urinary podocyte mRNAs increased during active disease but returned to baseline on disease remission. Furthermore, urine podocyte mRNAs increased in all categories of glomerular disease evaluated, but levels ranged from high to normal, consistent with individual patient variability in the risk for progression. In contrast, urine podocyte mRNAs did not increase in polycystic kidney disease. The association between proteinuria and podocyturia varied markedly by glomerular disease type: a high correlation in minimal-change disease and a low correlation in membranous nephropathy. These data support the podocyte depletion hypothesis as the mechanism driving progression in all human glomerular diseases, suggest that urine pellet podocyte mRNAs could be useful for monitoring risk for progression and response to treatment, and provide novel insights into glomerular disease pathophysiology.

Background: Casts are well known components of the urinary sediment. For most casts, the clinical associations are known and demonstrated, while for waxy casts they are totally unknown., Methods: Prospective study for the search and count of waxy casts in the urinary sediment of patients with different types of glomerular diseases., Results: Waxy casts were found in 39 out of 287 patients (13.6%), mostly in low number (1 to 9 out of 100 casts evaluated/sample). They were frequent in postinfectious glomerulonephritis and renal amyloidosis (5/9 patients, 44.5%, p=0.02 for each condition), while they were rare in membranous nephropathy (4/67 patients, 6.0%, 0.04) and absent in focal segmental glomerulosclerosis (0/23 patients, p=0.05). Waxy casts were associated significantly with higher serum creatinine levels (p<0.0001), with the presence of >1 leukocyte/HPF, granular casts and leukocytic casts (p=0.001 to 0.008) and with higher numbers of erythrocytes, leukocytes, renal tubular epithelial cells, granular casts, epithelial casts, and leukocytic casts (p<0.0001 to=0.03)., Conclusions: Waxy casts are uncommon and few in patients with glomerular diseases and are associated with impaired renal function and with several other structures of the urinary sediment., (Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Recently, serum soluble urokinase receptor (suPAR) has been proposed as a cause of two thirds of cases of focal segmental glomerulosclerosis (FSGS). It was noted to be uniquely elevated in cases of primary FSGS, with higher levels noted in cases that recurred after transplantation. It is also suggested as a possible target and marker of therapy., Methods: We studied serum and urine suPAR from pretransplantation banked samples from 86 well-characterized kidney transplant recipients and 10 healthy controls to determine its prognostic utility. Causes of native kidney disease were primary FSGS, diabetic nephropathy, membranous nephropathy, immunoglobulin A nephropathy, and autosomal dominant polycystic kidney disease. suPAR was measured using a commercially available enzyme-linked immunosorbent assay kit. Urinary suPAR was indexed to creatinine., Results: Both serum and urine suPAR correlated with proteinuria and albuminuria. Serum suPAR was found to be elevated in all transplant candidates with advanced renal disease compared with healthy controls and could not differentiate disease diagnosis. Urine suPAR was elevated in cases of recurrent FSGS compared with all other causes of end-stage renal disease. Recurrent FSGS cases had substantially higher proteinuria compared with all other cases. However, elevated urinary suPAR showed a trend in providing additional prognostic information beyond proteinuria in the small cohort of recurrent FSGS cases., Conclusion: In advanced renal disease, elevated serum suPAR is not unique to FSGS cases. Urinary suPAR appears to be higher in cases of FSGS destined for recurrence and merits further evaluation.

The location of segmental glomerular lesions in relation to the vascular or tubular pole may have diagnostic or prognostic significance. We have developed a model-based method to estimate the distance from a glomerular lesion to a given landmark (vascular or tubular pole) or the glomerular center and applied this to biopsies from 5 microalbuminuric, 5 normoalbuminuric and 7 proteinuric type 1 diabetic patients and 5 normal controls. The distance from each glomerular adhesion to the glomerulotubular junction was measured and divided by the glomerular radius, allowing comparability among different glomeruli, assuming a spherical shape for Bowman's capsule, an assumption which was validated. The frequency of adhesions in 6 glomerular zones with equal height (zone I adjacent to the glomerulotubular junction and zones II-VI progressively farther away) was determined: 59% of adhesions were in zone I, 15% in zone II, 16% in zone III, 7% in zone IV and 3% in zone VI (adjacent to the hilus). In glomeruli with only one adhesion, 82% of these were in zone I. This new method accurately localizes segmental lesions within glomeruli and revealed a marked predilection in type 1 diabetic patients for segmental sclerosis to develop at the glomerulotubular junction.

Context: Evaluating nontumor portions of tumor nephrectomies is useful to diagnose nonneoplastic renal disease., Objective: To determine the medical renal disease frequency and to assess the prognostic significance of the various renal pathologic variables with long-term follow-up in tumor nephrectomy patients., Design: We reviewed nonneoplastic kidney sections of 456 consecutive cases from 1998 to 2008. Seventy-five cases were excluded (19 tumor compression, 25 no nonneoplastic tissue, 22 embolized kidneys, 9 end stage). Special staining, immunofluorescence, and/or electron microscopy was performed where appropriate. Vascular sclerosis was scored from mild to severe; interstitial fibrosis/tubular atrophy and global glomerulosclerosis (GS) were expressed as percentages. Follow-up, minimum 12 months, was evaluated in 156 cases. All renal pathologic variables were compared with regard to change in creatinine level from preoperative assessment to follow-up., Results: Of 381 cases, 57 had additional medical renal disease (15%), most frequently diabetic nephropathy (28) and hypertensive nephropathy (11). Postoperative creatinine levels increased significantly in patients with severe arteriosclerosis or arteriolosclerosis, >5% GS, and >10% interstitial fibrosis/tubular atrophy. Seventy-four percent of cases with additional nonneoplastic diagnoses showed severe arteriolosclerosis. Higher corresponding GS was seen in the more affected vascular cases: mean, 5.56% GS for mild versus 23% GS for severe. Three patients progressed to renal failure 1 to 4 years after nephrectomy, 2 with hypertensive nephrosclerosis and 1 with diabetic nephropathy., Conclusions: Medical renal disease was identified in 15% of tumor nephrectomy specimens. The degrees of vascular sclerosis, GS, and interstitial fibrosis/tubular atrophy are predictive of elevated creatinine levels in postnephrectomy patients. Prognostic implications of the nontumor pathology are important in nephrectomized patients.

Recurrence of idiopathic focal segmental glomerulosclerosis (FSGS) following kidney transplantation occurs in a large percentage of patients. Accurate prediction of recurrence and elucidation of its pathogenesis are major therapeutic goals. To detect differential proteins related to FSGS recurrence, proteomic analysis was performed on plasma and urine samples from 35 transplanted idiopathic FSGS patients, divided into relapsing and nonrelapsing. Several proteins were detected increased in urine of relapsing FSGS patients, including a high molecular weight form of apolipoprotein A-I, named ApoA-Ib, found exclusively in relapsing patients. This finding was verified by Western blot individually in the 35 patients and validated in an independent group of 40 patients with relapsing or nonrelapsing FSGS, plus two additional groups: FSGS-unrelated patients showing different proteinuria levels (n = 30), and familial FSGS transplanted patients (n = 14). In the total of 119 patients studied, the ApoA-Ib form was detected in 13 of the 14 relapsing FSGS patients, and in one of the 61 nonrelapsing patients. Only one of the 30 patients with FSGS-unrelated proteinuria tested positive for ApoA-Ib, and was not detected in familial patients. Urinary ApoA-Ib is associated with relapses in idiopathic FSGS and warrants additional investigation to determine its usefulness as biomarker of relapse following transplantation., (© Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background and Objectives: In the FSGS Clinical Trial, 22 cyclosporine-treated and 20 mycophenolate/dexamethasone-treated patients experienced a complete or partial remission after 26 weeks, completed 52 weeks of treatment, and were studied through 78 weeks. Herein, changes in the urine protein/creatinine ratio (UP/C) and estimated GFR (eGFR) throughout the entire study period are defined., Design, Setting, Participants, and Measurements: The FSGS Clinical Trial, which was conducted from November 2004 to January 2010, enrolled patients aged 2-40 years, with eGFR ≥40 ml/min per 1.73 m(2) and UP/C >1 mg/mg after ≥4 weeks of corticosteroid therapy. Both groups received lisinopril or losartan throughout the study. UP/C and eGFR were measured at 0, 26, 52, and 78 weeks., Results: The median UP/C in the cyclosporine- and mycophenolate/dexamethasone-responsive patients fell by 89.8% and 82.7% at 52 weeks; the fall was largely sustained at 78 weeks (74.7% and 80.3%, respectively). The mean eGFR fell by 19.4% in the cyclosporine group and rose by 7.0% in the mycophenolate mofetil/dexamethasone group at 52 weeks, but subsequently rose by 16.4% and fell by 2.6%, respectively, in the two groups from 52 to 78 weeks., Conclusions: In this subset of responding FSGS patients, the improvement in UP/C after cyclosporine or mycophenolate/dexamethasone treatment was largely sustained for 6 months after therapy. Reduction in eGFR in the cyclosporine group was improved 6 months after cyclosporine was stopped although the levels were lower than baseline in seven patients who entered the study with decreased eGFR.

IgA nephropathy (IgAN), the most common primary glomerulonephritis, is characterized by deposition of IgA in the glomerular mesangium. The diagnosis of IgAN still requires a kidney biopsy that cannot easily be repeated in the same patient during follow-up. Therefore, identification of noninvasive urinary biomarkers would be very useful for monitoring patients with IgAN. We first used bidimensional electrophoresis (2DE) coupled to MALDI-TOF-TOF and Western blot to identify some urinary biomarkers associated with IgAN. Urine of IgAN patients showed an increase of albumin fragments, α-1-antitrypsin and α-1-β-glycoprotein, along with a decrease of a single spot that was identified as the laminin G-like 3 (LG3) fragment of endorepellin. The urinary proteomes of 43 IgAN patients were compared to those of 30 healthy individuals by ELISA. Quantification of LG3 confirmed a significant decrease in the urine of IgAN patients compared to healthy controls, except in ten patients in whom LG3 was increased. These ten patients had a more severe disease with lower glomerular filtration rate values. We found a significant inverse correlation between LG3 levels and glomerular filtration rate in the 43 patients with IgAN, which was not observed in 65 patients with other glomerular diseases including membranous nephropathy (23), lupus nephropathy (13), focal segmental glomerulosclerosis (15), diabetic nephropathy (14), and six patients with nonglomerular diseases. Therefore, we suggest that the LG3 fragment of endorepellin could be associated with IgAN severity and might be related to pathogenesis of IgAN., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: The study was undertaken to develop a potential new markers for distinguishing minimal change nephrotic syndrome (MCNS) and focal segmental glomerulosclerosis (FSGS) in children. We hypothesized that matrix metalloproteinase-9/neutrophil gelatinase-associated lipocalin (MMP-9/NGAL) is a better marker of focal sclerosis in the glomerulus then matrix metalloproteinase-9/tissue inhibitor of metalloproteinase-1 (MMP-9/TIMP-1) and matrix metalloproteinase-2/tissue inhibitor of metalloproteinase-2 MMP2/TIMP-2., Methods: The present study used a sample of 36 children and adolescents subdivided into two groups: I - 20 children with MCNS, subjected to examination twice: A - in relapse of nephrotic syndrome, before treatment and B - after regression of proteinuria; II - 16 children with FSGS. MMPs and TIMPs and NGAL levels were measured in the urine using ELISA kit. MMP-9/TIMP-1, MMP-2/TIMP-2 and MMP-9/NGAL ratios were calculated., Results: Median NGAL/cr. was significantly higher in MCNS and FSGS patients when compared to healthy controls. Both, NGAL and MMP-9 urinary levels were significantly elevated in FSGS subjects, as compared with control subjects. Contrary to FSGS children, in MCNS group, before treatment only NGAL/cr., but not MMP-9/cr. was increased. Urinary concentrations of NGAL and MMP-9 were highly associated with each other (NGAL/cr. vs. MMP-9/cr., r=0.485, p<0.01). Median urine MMP-9/NGAL ratio in FSGS patients was significantly higher than in patients with MCNS. We also found that significant increase in MMP-9/NGAL was associated with FSGS [odds ratio (OR) - 9.0; confidence interval (CI) 1.97-41.07]., Conclusion: MMP-9/NGAL ratio may serve as differentiation marker between MCNS and FSGS in nephrotic children.

Background: Podocin mutations are characterized by progression to end stage renal disease and histologic findings of Focal Segmental Glomerulosclerosis (FSGS). CD80 is a podocytes protein that may play a role in proteinuria, particularly in Minimal Change Disease whereas the soluble urokinase receptor (suPAR) is characteristically elevated in the serum of FSGS patients., Methods: In a patient with nephrotic syndrome and podocin mutation, urinary and serum CD80 as well as suPAR were measured using commercially available kits. Urinary CD80 molecular size was determined by western blot analysis. Glomerular staining for CD80 and podocin was performed., Results: Patient displayed marked elevated CD80 and mildly increased suPAR urinary levels compared to controls. Serum CD80 level was within the range observed in normal controls. Serum suPAR level was elevated, albeit in the lower range reported for patients with primary FSGS. Immunofluorescence examination of kidney biopsy revealed glomerular CD80 expression., Conclusion: The combination of serum and urinary biomarkers can help differentiate various forms of FSGS. High urinary CD80 and elevated serum and urinary suPAR might represent a profile to differentiate this genetic form of FSGS from primary FSGS.

Objective: To assess whether high-molecular-weight proteins excretion predicts outcome and therapy-responsiveness in patients with FSGS and nephrotic syndrome., Research Design and Methods: Thirty-eight patients measured at biopsy fractional excretion of IgG (FEIgG) and urinary α2-macroglobulin/creatinine ratio ( α m/C). Low and high risk groups were defined by cutoffs assessed by ROC analysis. In all patients first-line therapy was with steroids alone or in combination with cyclophosphamide., Results: α2m/C and FEIgG were correlated with segmental sclerosis (r = 0.546; r = 0.522). Twenty-three patients (61%) entered Remission and 9 (24%) progressed to ESRD. Comparing low and high risk groups, by univariate analysis remission was predicted by FEIgG (77% versus 25%, P = 0.016) and α2m/C (81% versus 17%, P = 0.007) and ESRD at best by FEIgG (0% versus 75%, P < 0.0001) and α2m/C (4% versus 67%, P < 0.0001). By multivariate analysis FEIgG was the only independent predictor of remission and α2m/C the most powerful predictor of ESRD. Low and high risk groups of FEIgG and α2m/C in combination had very high predictive value of sustained remission and ESRD in response to therapy., Conclusions: FEIgG and α2m/C are powerful predictors of outcome and responsiveness to steroids and cyclophosphamide; their predictive value, if validated in prospective studies, may be useful in clinical practice suggesting first-line alternative treatments in high risk patients.

Background and Objectives: Podocalyxin (PCX) is present on the apical cell membrane of podocytes and is shed in urine from injured podocytes. Urinary podocalyxin (u-PCX) is associated with severity of active glomerular injury in patients with glomerular diseases. This study examined the relationship between number of urinary podocytes, levels of u-PCX, and glomerular injury in adults with IgA nephropathy (IgAN)., Design, Setting, Participants, & Measurements: Urine samples voided in the morning on the day of biopsy were obtained from 51 patients with IgAN (18 men and 33 women; mean age, 31 years). All renal biopsy specimens were analyzed histologically. Pathologic variables of IgAN were analyzed per Shigematsu classification, the Oxford classification of IgAN, and the Clinical Guidelines of IgAN in Japan. Levels of u-PCX were measured by sandwich ELISA., Results: Histologic analysis based on Shigematsu classification revealed a significant correlation between levels of u-PCX and severity of acute extracapillary abnormalities (r=0.72; P<0.001), but levels of urinary protein excretion did not correlate with acute glomerular abnormalities. Levels of urinary protein excretion in patients with segmental sclerosis (n=19) were higher than in patients without (n=22) (0.49 [interquartile range (IQR), 0.20-0.88] g/g creatinine versus 0.20 [IQR, 0.10-0.33] g/g creatinine; P<0.01). The number of urinary podocytes in patients with segmental sclerosis was higher than in patients without (1.05 [IQR, 0.41-1.67] per mg creatinine versus 0.28 [IQR, 0.10-0.66] per mg creatinine; P<0.01)., Conclusions: Levels of u-PCX and the number of urinary podocytes are associated with histologic abnormalities in adults with IgAN.

Introduction: Neutrophil gelatinase-associated lipocalin (NGAL) is proposed as a marker of chronic kidney disease (CKD). This study was designed to find whether there is a correlation between urine NGAL and progression of kidney damage in children with focal segmental glomerulosclerosis (FSGS)., Materials and Methods: Data were collected at the initial diagnosis of FSGS and after 12 months of treatment based on the Mendoza protocol. Twelve children with FSGS and 15 healthy children were included. Urine NGAL was assessed at the initiation of the study in the two groups and after 1 year of receiving the treatment in the FSGS group., Results: Urine NGAL was elevated in the FSGS group (350.0 ± 67.2 ng/mL) as compared to that in the control group (9.3 ± 3.8 ng/mL; P < .001), and there was a significant decline after 1 year (180.0 ± 45.9 ng/mL) in the FSGS group (P < .001). There were significant inverse correlations between urine NGAL and estimated creatinine clearance in the FSGS patients both at diagnosis (r = -0.589, P = .03), and after 1 year (r = -0.76, P = .009). There was a significant correlation between urine NGAL and urinary protein excretion in FSGS patients at diagnosis (r = 0.628, P = .005)., Conclusions: Urine NGAL in children with FSGS can be used as a marker of progression of kidney damage as expressed in its positive correlation with both declining in glomerular filtration rate and the level of proteinuria even in those with remission.

Background: Parietal epithelial cells (PECs) and podocytes are the 2 epithelial cell types in the glomerulus. In contrast to podocytes, PECs have the ability to proliferate lifelong, and they can transdifferentiate into other cell types. We previously published that excretion of podocalyxin (PDX)-positive PECs in the urine correlates with disease activity in different glomerular diseases., Methods: In this analysis we investigated whether excretion of PDX-positive cells in the urine might have a prognostic value for proteinuria development and kidney function in focal segmental glomerulosclerosis (FSGS)., Results: We found that patients diagnosed with FSGS and with significant excretion of PDX-positive cells in the urine had a negative change in serum creatinine in the follow-up analysis. In contrast to that, FSGS-patients without excretion of PDX-positive cells showed a positive change in serum creatinine. There was a significant negative correlation between PDX-positive cells in the urine and change in serum creatinine. Mean change in urine protein in FSGS patients with excretion of PDX-positive cells in the urine did not differ significantly from patients with no cell excretion, but we could demonstrate a negative correlation between PDX-positive cells and change in total urine protein., Conclusions: Our data suggest that FSGS patients excreting large amounts of PDX-positive cells in their urine have a better outcome regarding kidney function and proteinuria compared with patients without excretion of PDX-positive cells. These data imply that PDX-positive cells have a positive effect on podocyte regeneration in FSGS patients.

Background: Focal segmental glomerulosclerosis (FSGS) presents a range of potentially serious complications, including acute kidney injury (AKI), infection and thromboembolism. This study aimed to find out the incidence rates and risk factors for these complications in FSGS patients., Methods: Patients with biopsy-proven primary FSGS and nephrotic-range proteinuria were included in this study. A short-term (16-week) follow-up was performed to observe the aforementioned complications. Clinical characteristics of patients were recorded upon enrollment. AKI was diagnosed as an absolute increase in serum creatinine of ≥0.3 mg/dL or a percentage increase of ≥50% within 48 hours; infection, by a combination of clinical manifestations, laboratory tests and imaging examinations; and thromboembolism, by imaging methods. Risk factors for complications were evaluated by logistic regression model., Results: The study population included 90 FSGS patients (63 males, mean age 28.9 ± 12.9 years). The incidences of AKI, infection and thromboembolism were 44.4%, 25.6% and 12.2%, respectively. Patients with AKI were more likely to be male, with lower serum albumin, greater proteinuria and more severe acute tubulointerstitial damage. Patients with infection had higher proteinuria and lower serum albumin, globulin and IgG. Circulating endothelial cells (CECs) and von Willebrand factor were higher in patients with thromboembolism. Logistic regression showed that increased urine retinol-binding protein, decreased serum albumin and IgG, and increased CECs and hemoglobin were independent risk factors for AKI, infection and thromboembolism, respectively., Conclusions: AKI, infection and thromboembolism are common among FSGS patients. Awareness of risk factors and prevention of these complications are important for the prognosis of these patients.

Background: The criterion of a renal biopsy in children with asymptomatic persistent isolated proteinuria is controversial., Methods: To determine an adequate renal biopsy criterion in children with asymptomatic constant isolated proteinuria, the optimal cutoff maximum urinary protein/creatinine ratio (uP/Cr) to separate minor glomerular abnormalities (MGA) and other significant glomerular changes was obtained by receiver operating characteristic analysis in 44 children with asymptomatic constant isolated proteinuria (uP/Cr ≥ 0.2 g/g) screened from 1167 patients who underwent a renal biopsy between September 2000 and April 2010. Patients were divided into two groups according to the cutoff value to verify its validity., Results: The optimal uP/Cr was 0.5 g/g. In Group 1 (uP/Cr <0.5 g/g, n = 15), only one patient (6.7%) showed focal segmental glomerulosclerosis (FSGS) and the other 14 patients (93.3%) had MGA. In Group 2 (uP/Cr ≥ 0.5 g/g at least once before biopsy, n = 29), 5 patients showed FSGS and 7 patients had nephritis such as IgA nephropathy (41.4%, n = 12) and the other 17 patients (58.6%) showed MGA. These findings indicated that the ratio of non-MGA/MGA was significantly higher in Group 2 than that in Group 1 (P = 0.016) and that if renal biopsies were performed with a criterion of a maximum uP/Cr ≥ 0.5 g/g (criterion for Group 2), renal biopsies could be avoided in 45.2% of patients with MGA. One patient with FSGS in Group 1 showed proteinuria with uP/Cr ≥ 0.5 g/g in the clinical course., Conclusions: An adequate renal biopsy criterion in children with asymptomatic constant isolated proteinuria is uP/Cr ≥ 0.5 g/g.

Objective: To determine risk factors for high blood pressure (BP), increased markers of glomerulosclerosis, and tubular dysfunction in 4-year-old preterm-born children., Study Design: The study group was a longitudinal cohort of 119 children with BP, albuminuria, and β2 microglobulin measurements obtained during the neonatal period and at age 4 years., Results: Systolic BP was >95(th) percentile in 15 (12.6%) of the children at age 4 years and lower in those born small for gestational age compared with those born appropriate for gestational age. Preterm-born 4-year-olds with height <-1 SD had lower systolic and diastolic BP, and 14.4% of the 4-year-olds had albuminuria. Albuminuria was less prevalent in the 4-year-olds with height <-1 SD than in those with height ≥-1 SD (6.8% vs 19.3%; P=.04). Mean albuminuria level was 1.0±0.7 mg/mmol in 4-year-olds with height <-1 SD and 1.4±1.3 mg/mmol in those with height ≥-1 SD. In multivariate analysis, albuminuria level was increased by 0.4±0.2 mg/mmol in preterm-born children with normal height at age 4, and by 0.5±0.2 mg/mmol in females, after adjustment for gestational age, sex, neonatal morbidity, and intrauterine growth restriction. These results were unchanged after adjustment for body mass index., Conclusion: Normal height at age 4 years may be associated with an increased risk for glomerulosclerosis in preterm-born children., (Copyright © 2012 Mosby, Inc. All rights reserved.)

Background: Several renal histopathological features, including mesangial hypercellularity, glomerulosclerosis, tubular atrophy and interstitial fibrosis, are considered to be independent predictors of end-stage renal failure in patients with glomerular diseases. Mesangial proliferative glomerulonephritis (MesPGN) is characterized by proliferations of mesangial cells with increase in mesangial matrix and/or deposits in mesangial region. The purpose of this study is to determine the association between urinary protein markers measured at the same time as renal biopsy and the severity of renal histological lesions in children with MesPGN, and to evaluate whether these markers could serve as predictors of severe renal histological lesions in this population., Methods: Ninety-eight children with MesPGN (40 with IgA nephropathy, 37 with IgM nephropathy, and 21 with MesPGN without IgA/IgM deposition) were enrolled. Urinary level of IgG, albumin, transferrin, α1-microglobulin, β2-microglobulin and N-acetyl-β-glucosaminidase from a morning sample before biopsy was measured.The scores of mesangial hypercellularity, glomerulosclerosis, and tubule-interstitial damage were used to semi-quantitatively evaluate renal histological lesions., Results: The urine proteins, as independent factors associated with severe mesangial cellularity (> 5 mesangial cells/ mesangial area) were transferrin, albumin, α1-microglobulin, IgG and 24-hour total protein, with severe glomerulosclerosis (≥ 10 % glomeruli showing segmental adhesions or sclerosis) were transferrin and 24-hour total protein, and with severe tubule-interstitial damage (focal or diffuse tubular and interstitial lesions) were transferrin and N-acetyl-β-glucosaminidase. Urinary transferrin achieved the area under-the-receiver-operating-characteristic curve (AUC) of 0.86 and 0.82, respectively, for predicting severe mesangial cellularity and glomerulosclerosis. Urinary N-acetyl-β-glucosaminidase achieved the highest AUC of 0.82 for predicting severe tubule-interstitial damage. The combination of urinary protein markers, however, did not improve the predictability for renal histological lesions., Conclusions: Urinary protein markers are useful to predict the severity of renal histological lesions in children with MesPGN, which suggests that urinary proteins might be useful to predict the development and progression of renal histological lesions, and assist in evaluating the outcome and prognosis in children with MesPGN as non-invasive and easily repeatable indicators on the follow-up examination.

Background: Among African-Americans, genome wide association revealed a strong correlation between the G1 and G2 alleles of APOL1 (apolipoproteinL1, also called trypanolytic factor) and kidney diseases including focal and segmental glomerulosclerosis, HIV-associated nephropathy and hypertensive nephrosclerosis. In the prevailing hypothesis, heterozygous APOL1 G1 and G2 alleles increase resistance against Trypanosoma that cause African sleeping sickness, resulting in positive selection of these alleles, but when homozygous the G1 and G2 alleles predispose to glomerulosclerosis. While efforts are underway to screen patients for G1 and G2 alleles and to better understand "APOL1 glomerulopathy," no data prove that these APOL1 sequence variants cause glomerulosclerosis. G1 and G2 correlate best with glomerulosclerosis as recessive alleles, which suggests a loss of function mutation for which proof of causality is commonly tested with homozygous null alleles. This test cannot be performed in rodents as the APOL gene cluster evolved only in primates. However, there is a homozygous APOL1 null human being who lives in a village in rural India. This individual and his family offer a unique opportunity to test causality between APOL1 null alleles and glomerulosclerosis., Methods and Findings: We obtained clinical data, blood and urine from this APOL1 null patient and 50 related villagers. Based on measurements of blood pressure, BUN, creatinine, albuminuria, genotyping and immunoblotting, this APOL1 null individual does not have glomerulosclerosis, nor do his relatives who carry APOL1 null alleles., Conclusions: This small study cannot provide definitive conclusions but the absence of glomerulosclerosis in this unique population is consistent with the possibility that African-American glomerulosclerosis is caused, not by loss of APOL1 function, but by other mechanisms including a subtle gain of function or by the "genetic hitchhiking" of deleterious mutations in a gene linked to APOL1 G1 and G2.

The steadily increasing incidence of kidney injury is a significant threat to human health. The current tools available for the early detection of kidney injury, however, have limited sensitivity or specificity. Thus, the development of novel biomarkers to detect early kidney injury is of high importance. Employing mouse renal ischemia-reperfusion and streptozotocin (STZ)-induced renal injury as acute and chronic kidney injury model, respectively, we assessed the alteration of microRNA (miRNA) in mouse urine, serum and kidney tissue by TaqMan probe-based qRT-PCR assay. Our results demonstrated that kidney-enriched microRNA-10a (miR-10a) and microRNA-30d (miR-30d) were readily detected in mouse urine and the levels of urinary miR-10a and miR-30d were positively correlated with the degree of kidney injury induced by renal ischemia-reperfusion or STZ diabetes. In contrast, no such alteration of miR-10a and miR-30d levels was observed in mouse serum after kidney injury. Compared with the blood urea nitrogen (BUN) assay, the test for urinary miR-10a and miR-30d levels was more sensitive for the detection of acute kidney injury. Furthermore, the substantial elevation of the urinary miR-10a and miR-30d levels was also observed in focal segmental glomerulosclerosis (FSGS) patients compared to healthy donors. In conclusion, the present study collectively demonstrates that urinary miR-10a and miR-30d represent a novel noninvasive, sensitive, specific and potentially high-throughput method for detecting renal injury.

Autosomal dominant polycystic kidney disease (ADPKD) with nephrotic syndrome is a rare coincidence. Among 19 reported cases since 1972, focal glomerulosclerosis is the dominant reported pathology. Here, we report the 6th case of focal segmental glomerulosclerosis with ADPKD. A 29-year-old man with a history of APCDK presented with massive proteinuria. He had a history of concurrent leptospirosis and brucellosis, and trace proteinuria and mild hypertension had been diagnosed 4 years earlier. Urine study showed proteinuria (21 g/d) and hematuria. Kidney biopsy report was compatible with focal and segmental sclerosis. The patient received prednisolone and cyclosporine. After 4 months, proteinuria decreased to 600 mg/d. Patients with ADPKD who show massive proteinuria should undergo kidney biopsy. It is possible that different mutations in these patients could clarify the nature of this coincidence.

Background: Podocyte proteins are involved in the pathogenesis of glomerular kidney disease (GKD). However, there is little information on messenger RNA (mRNA) expression patterns of B7-1 and NPHS1 in urinary sediment of patients with GKD. The objective of this study was to analyse the gene expression of B7-1 in urinary sediment and correlate it with the expression of podocyte-specific genes in patients with GKD., Methods: Adult patients with proliferative and non-proliferative GKD, proteinuria and stable renal function, were included. A group of healthy subjects was used to determine normal levels of urinary markers and to obtain reference RNA. Biochemical, clinical and experimental procedures included measurement of creatinine level and total urinary protein, renal biopsy, identification of urinary podocytes, gene expression analysis of B7-1, NPHS1, NPHS2 and SyNPO genes and urinary B7-1 protein analysis by enzyme-linked immunosorbent assay., Results: Between June 2006 and November 2009, 69 patients with GKD (median age: 46 ± 15 years, 64% men) and 14 healthy subjects (median age: 34 ± 12 years, 43% men) were included. In both groups, urinary mRNA levels of B7-1 and NPHS1 were significantly higher in patients with GKD compared to healthy subjects (P = 0.050 and P = 0.008, respectively). Regarding GKD subtypes, patients with focal segmental glomerulosclerosis (FSGS), but not patients with minimal change disease (MCD), had a significantly higher mRNA expression of B7-1 and NPHS1 than healthy subjects (P = 0.012 and P = 0.030, respectively). Patients with MCD had a significantly lower NPHS1 mRNA expression than patients with FSGS (P = 0.012). The B7-1:NPHS1 urinary mRNA ratio was significantly higher in patients with MCD compared with patients with FSGS (P = 0.027)., Conclusion: mRNA expression analysis of B7-1 and NPHS1 in urinary sediment may be useful to differentiate between different histologic subtypes of GKD, particularly between MCD and FSGS.