Glomerular parietal epithelial expression of CD44 in minimal change nephrotic syndrome and primary focal segmental glomerulosclerosis: A clinico-pathological study

Introduction: Minimal change nephrotic syndrome (MCNS) and focal segmental glomerulosclerosis (FSGS) are the two common causes of nephrotic syndrome (NS) in both children and adults with overlapping clinical features, but with distinct prognostic and therapeutic implications. The distinction between these relies entirely on histopathology, which can sometimes be difficult. CD44 is expressed by activated parietal epithelial cells, plays a role in matrix deposition and thus in the pathogenesis of FSGS. Aims: To assess the expression of CD44 in MCNS and FSGS and to evaluate its association with the known clinical and histopathological prognostic factors. Materials and Methods: Thirty cases each of MCNS and FSGS were studied. The clinical, laboratory, histopathological, and CD 44 immunohistochemical data were recorded. The findings were analyzed and correlated. A P value of < 0.05 was considered statistically significant. Results: Statistical association was noted between CD44 positivity and serum creatinine (p = 0.031), estimated glomerular filtration rate (p = 0.040), segmental sclerosis (p < 0.001), tubular atrophy (p = 0.027), interstitial fibrosis (p = 0.027), and histological diagnosis (p < 0.001). The sensitivity, specificity, positive predictive, and negative predictive values were 90%, 76.67%, 79.41% and 88.46%, respectively. Conclusions: CD44 immunostain can effectively distinguish MCNS from FSGS. The congruent results of CD44 positivity with known prognostic factors support the possibility of using the CD44 marker as a predictive tool in selecting high-risk patients and offering appropriate therapeutic measures.

Clinicopathological features analysis of focal segmental glomerulosclerosis after kidney transplantation / 器官移植

Objective To investigate the clinicopathological features of recurrent and de novo focal segmental glomerulosclerosis (FSGS) after kidney transplantation. Methods Thirty-four recipients pathologically diagnosed with FSGS by renal allograft biopsy were enrolled in this clinical trial. According to the detection of primary diseases of renal allografts and circulating permeability factors, 34 recipients were divided into the recurrent FSGS group (n=12) and de novo FSGS group (n=22). The differences of clinical indexes and the degree of pathological injury of renal allografts were compared between two groups. Results There was no significant difference in the mesangial hyperplasia score, glomerulosclerosis rate, renal tubular atrophy score, interstitial fibrosis score and podocyte proliferation rate between two groups (all P > 0.05). In the recurrent FSGS group, segmental glomerulosclerosis rate of the recipients was 0.10 (0.08, 0.27), lower than 0.19 (0.13, 0.33) in the de novo FSGS group (P < 0.05). No significant difference was found in the incidence of antibody-mediated rejection, drug-induced renal tubular injury and BK virus infection between two groups (all P > 0.05). The incidence of T cell-mediated rejection in the recurrent FSGS group was 17%, lower than 55% in the de novo FSGS group (P < 0.05). Immunohistochemical staining showed that the infiltrating inflammatory cells in the renal allografts were mainly T lymphocytes. The positive rates of C4d deposition in peripheral capillaries between the recurrent and de novo FSGS groups were 33% (4/12) and 32% (7/22), with no significant difference (P > 0.05). Immunofluorescence results revealed IgM deposition in the segmental glomerulosclerosis area of renal allografts in most cases. Electron microscopy showed extensive fusion or segmental distribution of podocytes in the glomerulus of renal allografts. Conclusions The degree of renal functional injury and the incidence of T cell-mediated rejection in the recurrent FSGS group are lower than those in the de novo FSGS group. Comprehensive analysis of preoperative and postoperative clinical manifestations, laboratory testing and pathological examination of kidney transplant recipients contribute to early diagnosis and treatment of recurrent and de novo FSGS.

Role of suPAR in the Pathogenesis of Podocyte Injury of Primary Focal Segmental Glomerulosclerosis / 中山大学学报(医学科学版)

ObjectiveThis study aims to investigate the role of suPAR in the pathogenesis of podocyte injury in FSGS. Methods① The sera of primary FSGS patients （17 cases） were collected. Healthy volunteers （10 cases） and patients with other types of primary nephrotic syndrome （10 cases） were set as normal and disease controls. SuPAR levels were detected by ELISA； ② Podocytes were stimulated by suPAR in vitro， and cells were collected to analyze apoptosis by flow cytometry and for RNAseq analysis； ③ Differentially expressed genes （DEGs） were screened from RNAseq data. Both up-regulated and down-regulated genes were analyzed by KEGG and GO enrichment analysis. Heat map was used to show expression of genes related to podocyte focal adhesion， slit diaphragm and actin dynamics and endocytosis. Differentially expressed genes were verified by qPCR. Results① The level of suPAR in FSGS patients was significantly increased， and that in other nephrotic syndrome（NS） patients was also significantly increased； ② suPAR stimulation significantly altered the transcriptome pattern of human podocytes. A total of 272 up-regulated genes and 288 down-regulated genes were screened； ③ KEGG and GO enrichment analysis of up-regulated and down-regulated genes showed that Focal adhesion and DNA replication and DNA repair related pathways were significantly down-regulated； ④ suPAR did not increase podocyte apoptosis. ConclusionThe level of suPAR is significantly increased in patients with primary FSGS. SuPAR may promote podocyte injury by interfering with genomic homeostasis and disrupting focal adhesion， slit diaphragm， actin dynamics and endocytosis-related functional molecules of podocytes.

De Novo Focal Segmental Glomerulosclerosis (FSGS) Post Covid 19 Vaccination: Case Series in A Single Centre in Malaysia

@#Introduction: Mass COVID-19 vaccination has been pivotal in the fight against this pandemic. The occurrence of glomerular disease following COVID-19 vaccinations particularly mRNA vaccine has been reported. The reported cases in the region are limited and number of cases reported are low in contrast to the total number of vaccine doses given worldwide, the healthcare providers should be alerted about such issues to provide swift and proper management. Case Series: Here, we report 3 cases of Focal segmental glomerulosclerosis (FSGS) following COVID-19 vaccination and their outcomes. Two of the patients received BNT162b2 vaccination and one received CoronaVac vaccination. The mean age of the patients was 33+/-7 years old. The mean duration onset of FSGS was 23+/-19 days post vaccinations. Two of the patients (BNT162b2 vaccination and CoronaVac vaccination) achieved complete remission after corticosteroid therapy. This is the first reported case of De Novo FSGS following CoronaVac vaccination in the literature. The third patient, who received BNT162b2 vaccination and presented late (42 days post vaccination) was not in remission despite three months of immunosuppressive treatment. Conclusion: The treating physician needs to be aware of the possibility of the development of FSGS associated with COVID-19 vaccination and how to proceed with vaccination schedule in these populations. Overall, the advantage of COVID-19 vaccination far outweighs the possibility of COVID-19 vaccine-associated glomerular disease.

Takayasu arteritis associated with focal and segmentary glomerulosclerosis

Takayasu arteritis (TA) is a large vessel vasculitis that affects young people, related to cardiovascular outcomes and chronic kidney disease. We present the case of a 20-year-old male with a diagnosis of TA, who developed chronic kidney disease, impaired renal blood flow was ruled out, renal biopsy was compatible with focal and segmental glomerulosclerosis of a collapsing variety, other possible aetiologies were excluded. The mechanisms that mediate this association have not been determined, immune-mediated mechanisms are proposed. According to our review, this is the second reported case of this association and the first with a collapsing variety.

La arteritis de Takayasu es una vasculitis de grandes vasos que afecta a personas jóvenes y se relaciona con desenlaces cardiovasculares y enfermedad renal crónica. Se presenta el caso de un paciente masculino de 20 arios, con diagnóstico de arteritis de Takayasu, que desarrolla enfermedad renal crónica. Se descartan alteraciones en el flujo sanguíneo renal, en tanto que la biopsia renal resulta compatible con glomeruloesclerosis focal y segmentaria de variedad colapsante. Se excluyeron otras posibles etiologías. No se han determinado los mecanismos que median en esta asociación; se proponen mecanismos inmunomediados. Según nuestra revisión, se trata del segundo caso reportado de esta asociación y el primero con variedad colapsante.

Focal segmental glomerulosclerosis in a patient with congenital lecithin-cholesterol acyltransferase deficiency

Lecithin-cholesterol acyltransferase deficiency is a rare genetic disease caused by a mutation of the gene coding for the lecithin-cholesterol acyltransferase protein, and mainly affects low density lipoprotein metabolism. It typically manifests with diffuse corneal opacities, normocytic anemia and kidney disease. We present the case of a 30-year-old man with chronic kidney disease and nephrotic syndrome. His initial kidney biopsy showed focal segmental glomerulosclerosis, thought to be primary, a disease which was refractory to multiple immunosuppressive schemes. Manifestations such as anemia, splenomegaly, corneal opacities and an association with low high-density lipoproteins alerted to the possibility of glomerular damage secondary to lecithin-cholesterol acyltransferase enzyme deficiency, which was confirmed through genetic sequenc ing. Due to the low incidence of the disease, diagnosis is a clinical challenge. The signs and symptoms tend to be interpreted as isolated events, which significantly delays its confirmation. Understanding this entity and the clinical exercise needed to arrive at its diagnosis will serve as a reference, resulting in the suspicion and reporting of cases in the future. (Acta Med Colomb 2022; 47. DOI:https://doi.org/10.36104/amc.2022.2558).

La deficiencia de lecitin-colesterol aciltransferasa es una enfermedad genética rara, causada por una mutación en el gen que codifica la proteína lecitin-colesterol aciltransferasa y afecta principalmente el metabolismo de las lipoproteínas de baja densidad. Se manifiesta típicamente con opacidades corneales difusas, anemia normocítica y enfermedad renal. Se presenta el caso de un hombre de 30 años con enfermedad renal crónica y síndrome nefrótico, con biopsia renal inicial que demostró un patrón de glomeruloesclerosis focal y segmentaria, interpretada como primaria, enfermedad que fue refractaria a múltiples esquemas de inmunosupresión. Las manifestaciones como anemia, esplenomegalia, opacidades corneales y la asociación con lipoproteínas de alta densidad bajas, alertaron sobre la posibilidad de compromiso glomerular secundario a un déficit de la enzima lecitin-colesterol aciltransferasa, confirmado mediante estudio de secuenciación genética. Dada la baja incidencia de la enfermedad, el diagnóstico representa un desafío clínico. Las manifestaciones suelen interpretarse como eventos aislados, lo que lleva a retraso significativo en su confirmación. El conocimiento de esta entidad y el ejercicio clínico necesario para llegar al diagnóstico, servirán como referencia que derive en la sospecha y reporte de futuros casos. (Acta Med Colomb 2022; 47. DOI:https://doi.org/10.36104/amc.2022.2558).

Rituximab therapy for adult patients with idiopathic focal segmental glomerulosclerosis / 中华肾脏病杂志

Objective:To evaluate the efficacy and safety of rituximab in the treatment of adult primary focal segmental glomerulosclerosis (FSGS).Methods:Adult FSGS patients treated with rituximab in the First Affiliated Hospital of Zhejiang University College of Medicine were retrospectively enrolled. One or two doses of rituximab (375 mg/m 2) were used aiming to achieve B cell depletion (defined as<5 B cells per microliter in peripheral blood) and the interval between the two doses was 2 weeks. The evaluated major outcomes were remission and relapse of nephropathy, and the secondary outcome measures were adverse events and renal outcomes. Results:A total of 14 patients (9 males) were enrolled, among whom 7 cases were steroid-dependent nephrotic syndrome (SDNS) or frequently relapsing nephrotic syndrome (FRNS), 6 cases were steroid-resistant nephrotic syndrome (SRNS) and one patient was new onset FSGS with contraindication to steroid. After treatment with rituximab, 7 patients with SDNS/FRNS achieved complete remission. At 6 months, the daily oral steroid dose reduced significantly compared with the baseline [(33.3±5.2) mg/d vs (6.7±6.6) mg/d, P<0.01]; while one patient still received tacrolimus 1.0 mg/d, the other 6 patients stopped using immunosuppressants; and the total number of relapse/total follow-up months decreased from 0.257 times/month to 0.058 times/month after the use of rituximab. For the other 6 SRNS patients and one patient with contraindication to steroid, three SRNS patients achieved partial remission and one patient with contraindication to steroid achieved complete remission at 34.50(20.25, 95.25) days after use of rituximab, and the other 3 SRNS patients failed to achieve remission, of whom one patient developed end stage renal disease at 23 months. Conclusions:Rituximab may reduce the risk of relapse and help steroid or immunosuppressant-tapering in adult steroid-dependent/frequently relapsing idiopathic FSGS. However, it is not effective in SRNS patients.

Scrub typhus leading to focal segmental glomerulosclerosis in a child due to genetic predisposition

Scrub typhus is a multisystem disease, caused by genera orientia tsutsugamushi and is currently endemic in India. In children, the disease may vary from a mild to a severe form. Complications include encephalitis, myocarditis, disseminated intravascular coagulation, acute kidney injury, atypical pneumonia, etc. The pathophysiologic mechanisms of renal involvement in scrub typhus include prerenal failure, septic shock, vasculitis, acute tubular injury and direct renal invasion by rickettsia. Here, authors present the case of a previously well 5-year old female child who was admitted to our hospital with a history of high-grade fever and pain abdomen. IgM scrub typhus turned out to be positive and she was adequately treated with doxycycline. She turned afebrile but then gradually developed anasarca, hematuria, proteinuria and persistent stage 2 hypertension. Kidney biopsy was done which revealed focal segmental glomerulosclerosis (FSGS). Further workup of the patient by whole exome sequencing revealed missense mutations in TBX18, INF2 and NPHS1 genes. Mutations in INF2 gene is a recently discovered cause of autosomal dominant FSGS. In our case, the scrub typhus mediated kidney injury probably acted as a trigger in unmasking FSGS in the already genetically susceptible child.

Research progress of the mechanism of rituximab in the treatment of focal segmental glomerulosclerosis / 上海交通大学学报（医学版）

Rituximab (RTX), as a monoclonal antibody of CD20 acting on B cell epitopes, has been applied to the field of kidney since 2005, and has become a research hotspot in the clinical treatment of glomerulonephritis. At present, in addition to its clinical safety and efficacy, some researchers are still committed to explore the mechanism of RTX in the treatment of renal diseases, trying to find out whether there is a specific target in renal tissue. In this paper, the mechanism of RTX in the treatment of focal segmental glomerulosclerosis is reviewed.

Unexpectedly High Prevalence of Low Alpha-Galactosidase A Enzyme Activity in Patients with Focal Segmental Glomerulosclerosis

OBJECTIVES: Fabry disease (FD) is a rare disease associated with sphingolipid accumulation. Sphingolipids are components of plasma membranes that are important in podocyte function and accumulate in various glomerular diseases such as focal segmental glomerulosclerosis (FSGS). Both FD and FSGS can cause podocyte damage and are classified as podocytopathies. In this respect, FD and FSGS share the same pathophysiologic pathways. Previous screening studies have shown that a significant proportion of end-stage renal disease (ESRD) patients receiving hemodialysis (HD) have unsuspected FD, and the prevalence of low alpha-galactosidase A (αGLA) enzyme activity in these patients is higher than that in the normal population. We aimed to compare αGLA enzyme activity in patients with biopsy-proven FSGS and ESRD receiving HD. METHODS: The records of 232 patients [62 FSGS (F/M: 33/29); 170 HD (M/F: 93/79)] were evaluated retrospectively. The screening was performed based on the αGLA enzyme activity on a dried blood spot, with the confirmation of plasma LysoGb3 levels, and the known GLA mutations were tested in patients with low enzyme activities. The two groups were compared using these parameters. RESULTS: The mean level of αGLA enzyme activity was found to be lower in FSGS patients than in the HD group (2.88±1.2 μmol/L/h versus 3.79±1.9 μmol/L/h, p<0.001). There was no significant relationship between the two groups with regard to the plasma LysoGb3 levels (2.2±1.22 ng/ml versus 1.7±0.66 ng/ml, p: 0.4). In the analysis of GLA mutations, a D313Y mutation [C(937G>T) in exon p] was found in one patient from the FSGS group. CONCLUSIONS: We found that αGAL activity in patients with FSGS is lower than that in patients undergoing HD. The low enzyme activity in patients with FSGS may be explained by considering the similar pathogenesis of FSGS and FD, which may also lead to sphingolipid deposition and podocyte injury.

Retrospective analysis of clinical data and treatment of primary focal segmental glomerulosclerosis patients / Análisis retrospectivo de datos clínicos y tratamiento de pacientes con glomeruloesclerosis segmentaria focalprimaria

Abstract Introduction: The aim of the study is to compare clinical data of primary focal segmental glomerulosclerosis patients with other data in the literature. In addition, initial immunosuppressive therapy (steroid, calcineurin inhibitors) responses are aimed to be compared with the results in the literature. Methods: Forty seven patients, who were followed up for at least 12 months with primary focal segmental glomerulosclerosis as a result of kidney biopsy. Results of biochemical tests and treatment modalities were evaluated. Results: The mean age of the 47 patients with primary focal segmental glomerulosclerosis was 45.68 (± 13.92). Twenty-one (44.6 %) of 47 patients had anangiotensin converting enzyme inhibitor / angiotensin receptor blocker, 7 (14.8 %) had only corticosteroids, and 6 (12. 7%) had calcineurin inhibitor + low-dose corticosteroids treatment. Thirteen patients (27.6 %) used calcineurin inhibitor + low-dose corticosteroids after receiving corticosteroids treatment. The patients who received corticosteroids or calcineurin inhibitor + low-dose corticosteroids treatment as the initial treatment were compared at the 0, 6 and 12 months of treatment in terms of laboratory and clinical features. At the end of the first year, 4 out of 6 (66 %) patients with low-dose corticosteroids and calcineurin inhibitor and 6 out of (86 %) of 7 patients with corticosteroids had remission (p>0.05). Conclusion: We found the initial steroid treatment and calcineurin inhibitor treatment to be equally effective. We thought that patients with steroid intolerance could be given calcineurin inhibitor in the first step, but if the cost is considered, the first option, such as The Kidney Disease Improving Global Outcomes recommendation, was again steroid.

Resumen Introducción:El objetivo del estudio es comparar los datos clínicos de pacientes con glomeruloesclerosis segmentaria focal primaria con otros datos de la bibliografía. Asimismo, se busca comparar las respuestas de la terapia inmunosupresora inicial (esteroides, inhibidores de la calcineurina) con los resultados en las publicaciones citadas. Material y métodos: Se incluyeron 47 pacientes con glomeruloesclerosis segmentaria focal primaria como resultado de una biopsia renal, y cuyo seguimiento duró, al menos, 12 meses. Se evaluaron los resultados de las pruebas bioquímicas y las modalidades de tratamiento. Resultados: La edad media de los 47 pacientes con glomeruloesclerosis segmentaria focal primaria fue de 45,68 (± 13,92). 21 (44,6 %) del total de los pacientes tenían un inhibidor de la enzima convertidora de la angiotensina / bloqueante del receptor de la angiotensina. Siete pacientes (14,8 %) solo tenían corticosteroides y 6 (12,7 %) tenían un inhibidor de la calcineurina + un tratamiento con esteroides en dosis bajas. Se aplicóinhibidores de la calcineurina + dosis bajas de corticoesteroides en13 pacientes (27,6 %) después de recibir tratamiento con ciclosporina. Los pacientes que recibieron ciclosporina o inhibidores de la calcineurina+ dosis bajas de esteroides como tratamiento inicial se compararon al inicio del tratamiento, a los 6 y 12 meses en sus parámetros de laboratorio y características clínicas. Al final del primer año, 4 de 6 pacientes (66,7 %) con dosis bajas de ciclosporina e inhibidores de la calcineurina y 6 de 7 pacientes (85,7 %) con ciclosporina presentaron remisión (p>0,05). Conclusión: Se encontró que el tratamiento inicial con esteroides y el tratamiento con inhibidores de la calcineurinason igualmente efectivos. Pensamos que, a los pacientes con intolerancia a los esteroides, se les podría administrarinhibidores de la calcineurinaen el primer paso, pero si se considera el costo, la primera opción son nuevamente los esteroides, como lo recomienda el consorcio Kidney Disease Improving Global Outcomes.

The metabolomics signature associated with responsiveness to steroid therapy in focal segmental glomerulosclerosis: a pilot study

Abstract Background Focal segmental glomerulosclerosis (FSGS) is considered one of the most severe glomerular diseases and around 80% of cases are resistant to steroid treatment. Since a large proportion of steroid-resistant (SR) FSGS patients progress to end-stage renal disease, other therapeutic strategies may benefit this population. However, identification of non-invasive biomarkers to predict this high-risk population is needed. Objective We aimed to identify the biomarker candidates to distinguish SR from steroid-sensitive (SS) patients using metabolomics approach and to identify the possible molecular mechanism of resistance. Methods Urine was collected from biopsy-proven FSGS patients eligible for monotherapy with prednisolone. Patients were followed for 6-8 weeks and categorized as SS or SR. Metabolite profile of urine samples was analyzed by one-dimensional 1H-nuclear magnetic resonance (1H-NMR). Predictive biomarker candidates and their diagnostic importance impaired molecular pathways in SR patients, and the common target molecules between biomarker candidates and drug were predicted. Results Homovanillic acid, 4-methylcatechol, and tyrosine were suggested as the significant predictive biomarker candidates, while L-3,4-dihydroxyphenylalanine, norepinephrine, and gentisic acid had high accuracy as well. Tyrosine metabolism was the most important pathway that is perturbed in SR patients. Common targets of the action of biomarker candidates and prednisolone were molecules that contributed in apoptosis. Conclusion Urine metabolites including homovanillic acid, 4-methylcatechol, and tyrosine may serve as potential non-invasive predictive biomarkers for evaluating the responsiveness of FSGS patients.

Circulating Permeability Factors in Idiopathic Nephrotic Syndrome

Nephrotic syndrome (NS) is a common chronic glomerular disease in children characterized by significant proteinuria with resulting hypoalbuminemia, edema, and hyperlipidemia. Renal biopsy findings of diffuse foot processes effacement on electron microscopy and minimal change disease, focal segmental glomerulosclerosis (FSGS), or diffuse mesangial proliferation on light microscopy. It has been speculated that circulating permeability factors would be implicated in the pathogenesis of NS because they have been reportedly detected in the sera of patients and in experimental models of induced proteinuria. Moreover, a substantial portion of the patients with primary FSGS recurrence shortly after transplantation. This report reviews the current knowledge regarding the role of circulating permeability factors in the pathogenesis of proteinuria in NS and suggests future targeted therapeutic approaches for NS.

Analysis of a pedigree with autosomal dominant intermediate Charcot-Marie-Tooth disease type E and nephropathy / 中华医学遗传学杂志

Objective@#To explore phenotypic and mutational characteristics of a pedigree affected with autosomal dominant Charcot-Marie-Tooth disease (CMT) and nephropathy.@*Methods@#Clinical data of the proband and his family members was collected. Electrophysiology, renal biopsy and next-generation sequencing were carried out for the proband.@*Results@#The proband presented with distal lower limb weakness and proteinuria in childhood. His mother and brother had similar symptoms. Electrophysiological test of the proband revealed demyelination and axonal changes in both motor and sensory nerves. Renal biopsy suggested focal segmental glomerulosclerosis. Genetic testing revealed a heterozygous c. 341G>A (p.G114D) mutation in exon 2 of the INF2 gene.@*Conclusion@#The phenotypic feature of the pedigree is autosomal dominant intermediate CMT and focal segmental glomerulosclerosis, which may be attributed to the c. 341G>A mutation of the INF2 gene.

New Mutation of Coenzyme Q Monooxygenase 6 Causing Podocyte Injury in a Focal Segmental Glomerulosclerosis Patient / 中华医学杂志(英文版)

Background@#Focal segmental glomerulosclerosis (FSGS) is a kidney disease that is commonly associated with proteinuria and the progressive loss of renal function, which is characterized by podocyte injury and the depletion and collapse of glomerular capillary segments. The pathogenesis of FSGS has not been completely elucidated; however, recent advances in molecular genetics have provided increasing evidence that podocyte structural and functional disruption is central to FSGS pathogenesis. Here, we identified a patient with FSGS and aimed to characterize the pathogenic gene and verify its mechanism.@*Methods@#Using next-generation sequencing and Sanger sequencing, we screened the causative gene that was linked to FSGS in this study. The patient's total blood RNA was extracted to validate the messenger RNA (mRNA) expression of coenzyme Q monooxygenase 6 (COQ6) and validated it by immunohistochemistry. COQ6 knockdown in podocytes was performed in vitro with small interfering RNA, and then, F-actin was determined using immunofluorescence staining. Cell apoptosis was evaluated by flow cytometry, the expression of active caspase-3 was determined by Western blot, and mitochondrial function was detected by MitoSOX.@*Results@#Using whole-exome sequencing and Sanger sequencing, we screened a new causative gene, COQ6, NM_182480: exon1: c.G41A: p.W14X. The mRNA expression of COQ6 in the proband showed decreased. Moreover, the expression of COQ6, which was validated by immunohistochemistry, also had the same change in the proband. Finally, we focused on the COQ6 gene to clarify the mechanism of podocyte injury. Flow cytometry showed significantly increased in apoptotic podocytes, and Western blotting showed increases in active caspase-3 in si-COQ6 podocytes. Meanwhile, reactive oxygen species (ROS) levels were increased and F-actin immunofluorescence was irregularly distributed in the si-COQ6 group.@*Conclusions@#This study reported a possible mechanism for FSGS and suggested that a new mutation in COQ6, which could cause respiratory chain defect, increase the generation of ROS, destroy the podocyte cytoskeleton, and induce apoptosis. It provides basic theoretical basis for the screening of FSGS in the future.

Obesidade e doença renal: aspectos fisiopatológicos / Obesity and kidney disease: pathophysiological aspects

A epidemia de obesidade observada nas últimas décadas é acompanhada de aumento exponencial de doenças crônicas relacionadas, com destaque diabetes mellitus tipo 2, hipertensão arterial sistêmica, dislipidemia e doenças cardiovasculares. Do mesmo modo, a obesidade constitui fator de risco independente para o desenvolvimento de doença renal crônica, condição associada a elevados índices de morbidade e de mortalidade. A obesidade causa lesão renal de maneira indireta, por meio de sua estreita associação com hipertensão arterial sistêmica e com diabetes mellitus tipo 2 e de maneira direta, ao induzir adaptações glomerulares que culminam na glomerulopatia específica da obesidade. Além disso, o excesso de peso contribui para o agravamento de glomerulopatias pré-existentes. Múltiplos fatores explicam o desenvolvimento e o agravamento das lesões renais associadas à obesidade, em especial alterações hemodinâmicas, inflamatórias e metabólicas. Nesse contexto, a redução do peso corporal com ênfase nas alterações metabólicas e inflamatórias bem como o tratamento da hipertensão arterial e do diabetes mellitus constituem o primeiro passo para a prevenção primária e secundária do desenvolvimento de doença renal crônica. Nesta revisão serão apresentados os principais mecanismos fisiopatológicos da lesão renal associada à obesidade.

n the last decades, the obese epidemic has been accompanied by an exponential increase in the prevalence of chronic conditions such as type 2 diabetes, hypertension, dyslipidemia, and other forms of cardiovascular disease. Moreover, obesity is an independent risk factor for the development of chronic kidney disease, itself a condition associated with high risk of morbidity and mortality. Obesity can cause chronic kidney disease both indirectly, as a major risk factor for diabetes and hypertension, and directly, through adaptive glomerular changes that evolve into a specific form of glomerulopathy. Furthermore, excessive weight can worsen other forms of pre-existent glomerular diseases. Multiple factors can explain the development and worsening of renal lesions associated with obesity, mainly through hemodynamic, inflammatory and metabolic changes. In this context, reduction of body weight with emphasis on metabolic and inflammatory changes, as well as the treatment of hypertension and diabetes, constitute the first step towards primary and secondary prevention against development of chronic kidney disease. This review presents the physiopathology of the obesity related glomerulopathy.

Primary Focal Segmental Glomerulossclerosis and Minimal Change Disease as one Spectrum of Disease

@#Minimal Change Disease (MCD) and Focal Segmental Glomerulosclerosis (FSGS) are common causes of nephrotic syndrome. These two conditions are similar in their presentations but differentiated via their histopathological features and responsiveness to corticosteroids. There are ongoing debates whether MCD and FSGS are at the same spectrum of disease rather than separate entities. FSGS has been postulated to be the severe end of the spectrum of MCD. We have reported a case that has primary FSGS after years of poorly controlled MCD, which supports both conditions are the same spectrum of disease.

Analysis of prognosis of collapsing focal segmental glomerulosclerosis in children / 临床儿科杂志

Objective To analyze the long-term prognosis and prognostic factors of idiopathic collapsing focal segmental glomerulosclerosis (FSGS) and not otherwise specified FSGS in children. Methods The clinical, pathology and follow-up data of patients with idiopathic collapsing FSGS and not otherwise specified FSGS were analyzed retrospectively by Kaplan-Meier method, univariate and multivariate Cox regression analysis. Results A total of 64 patients (29 idiopathic collapsing FSGS and 35 not otherwise specified FSGS) were diagnosed by renal biopsy. The 4-year renal survival rate of idiopathic collapsing FSGS and not otherwise specified FSGS were 48.3%, 74.3% respectively. Univariate analysis revealed that the renal survival time were 25.41±3.28 months in idiopathic collapsing patients, and 35.53±2.73 months in not otherwise specified patients. The different is significant (χ2=4.07,P=0.044). Multivariate Cox regression analysis showed that poor treatment response (HR=5.92, P<0.05) and renal insufficiency at early stage (HR=2.45, P<0.05) were independent risk factors of prognosis. Conclusions Compared with patients with not otherwise specified FSGS, the renal survival time is shorter in idiopathic collapsing FSGS patients. Patients with renal insufficiency and poor response to treatment have poorer prognosis.

Mutation analysis of NPHS2 in Chinese Han adult-onset focal segmental glomerulosclerosis / 上海交通大学学报（医学版）

Objective·To screen NPHS2 mutations in adult focal segmental glomerulosclerosis(FSGS)patients based on a large Chinese FSGS cohort. Methods · All patients were biopsy determined FSGS by the Department of Nephrology at Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine. FSGS secondary to systemic disease and other hereditary kidney disease were excluded. After extraction of genomic DNA of peripheral blood,NPHS2 was screened by directly sequencing the exon/intron junction or high-throughput sequencing,including whole exon sequencing and Panel sequencing, and then verified by Sanger sequencing. One hundred healthy controls were enrolled to validate candidate mutations. Results · Two hundred and four FSGS patients were enrolled,including 52 familial(25.5%) and 152 sporadic patients(74.5%),of which steroid-resistant FSGS patients accounted for 30.3%(46/152).By sequencing NPHS2 in all patients of the cohort(Sanger sequencing in 61 patients and high-throughput sequencing in 143 patients), 2 novel conserved mutations were identified, one homozygous mutation in sporadic steroid-resistant FSGS, p.N199I and one heterozygous mutation in familial FSGS, p.L321fx346. Both of them were not detected in 100 healthy controls. These two variants were predicted to be damaging by Polyphen,SIFT and Mutation Taster.Totally,the mutation rate of NPHS2 in the FSGS cohort was 1%. Conclusion·Since the overall frequency of NPHS2 mutations is considerably low in Chinese adult-onset FSGS,NPHS2 is not the main disease-causing gene of this group of people.

Correlation between immunofluorescence deposition and corticosteroid effect in childhood focal segmental glomerulosclerosis manifesting with nephrotic syndrome / 上海交通大学学报（医学版）

Objective · To explore the correlation between immunofluorescence (IMF) deposition and corticosteroid effect in childhood focal segmental glomerulosclerosis (FSGS) manifesting with nephrotic syndrome (NS). Methods · Renal IMF deposition and clinical data of the children clinically diagnosed with NS and pathologically diagnosed with FSGS in the Department of Pediatric Nephrology in Xinhua Hospital, Shanghai Jiao Tong University from January 1990 to December 2015 were reviewed and analyzed retrospectively. Results · The renal pathological types classified by IMF of 47 patients diagnosed with FSGS manifesting with NS showed that 2 cases (4.26%) were IgA type, 12 cases (14.89%) were IgM type, 4 cases (8.51%) were complement (C) type, 1 case (2.13%) was IgG+A+M type, 5 cases (10.64%) were IgG+A+M+C type, 1 case (2.13%) was IgA+C type, 12 cases (25.53%) were IgM+C type, and there was no immune complexes present in 15 cases (31.91%). The IMF deposition showed 9 cases with IgA+, 25 cases with IgM+, 8 cases with IgG+, 23 cases with C3+, 3 cases with C4+, 6 cases with C1q+, 5 cases with FN+, 12 cases with all negative. After 4 weeks of treatment with oral prednisone at full dose, complete remission was presented in 34 cases (72.34%), partial remission was presented in 7 cases (14.89%), and no remission was presented in 6 cases (12.77%). There was no statistically difference in the corticosteroid effect among the different types of IMF (H=1.792, P=0.408). The corticosteroid effect had statistical differences between C1q+ and C1q- patients (χ2=7.22, P=0.027), while it had no significant differences in other conditions. Conclusion · In childhood FSGS manifesting with NS, C1q+ patients have relatively poor reaction to the corticosteroid therapy compared to C1q- ones.