Idiopathic Focal Segmental Glomerulosclerosis Research Articles

Kidney Disease Associated With Mono-allelic COL4A3 and COL4A4 Variants: A Case Series of 17 Families.

Mono-allelic variants in COL4A3 and COL4A4 (COL4A3/COL4A4) havebeen identified in a spectrum of glomerular basement membrane nephropathies, including thin basement membrane nephropathy and autosomal dominant Alport syndrome. With the increasing useof next generation sequencing, mono-allelic COL4A3/COL4A4 variants are detected morefrequently, but phenotypic heterogeneity impedes counseling. We aimed to investigate the phenotypic spectrum, kidney biopsy results, and segregation patterns of patients with mono-allelic COL4A3/COL4A4 variants identified by whole exome sequencing. Case series. We evaluated clinical andpathologic characteristics of 17 Dutch index patients with mono-allelic variants in COL4A3/COL4A4 detected by diagnostic whole exome sequencing and 25 affected family members with variants confirmed by Sanger sequencing. Eight different mono-allelic COL4A3/COL4A4 variants were identified across members of 11 families, comprising 7 glycine substituted missense variants and 1 frameshift variant. All index patients had microscopic hematuria at clinical presentation (median age 43 years) and 14 had (micro)albuminuria/proteinuria. All family members showed co-segregation of the variant with at least hematuria. At end of follow-up of all 42 individuals (median age 54 years), 16/42 patients had kidney function impairment, of whom 6 had kidney failure.Reports of kidney biopsies of 14 patients described thin basement membrane nephropathy, focal segmental glomerulosclerosis, minimal change lesions, and Alport syndrome. Electron microscopy images of 7 patients showed a significantly thinner glomerular basement membrane compared with images of patients with idiopathic focal segmental glomerulosclerosis and other hereditary glomerular diseases. No genotype-phenotype correlations could be established. Retrospective design, ascertainment bias toward severe kidney phenotypes, and familial hematuria. This study confirms the wide phenotypic spectrum associated with mono-allelic COL4A3/COL4A4 variants, extending from isolated microscopic hematuria to kidney failure with high intra- and interfamilial variability.

Extracellular vesicles from focal segmental glomerulosclerosis pediatric patients induce STAT3 activation and mesangial cell proliferation.

Primary focal segmental glomerulosclerosis (FSGS), a major cause of end-stage kidney disease (ESKD) in adolescents and young adults, is attributable to recognized genetic mutations in a minority of cases. For the majority with idiopathic primary FSGS, the cause of the disease is unknown. We hypothesize that extracellular vesicle (EVs), that carry information between podocytes and mesangial cells, may play a key role in disease progression. A total of 30 participants (20 primary nephrotic syndrome/ 10 healthy controls) were enrolled in this study. Primary nephrotic syndrome subjects were grouped based on pathologic diagnosis. The FSGS group was compared to healthy control subjects based on demographic and clinical findings. EVs were isolated from the urine of each group before being characterized by Western blotting, transmission electron microscopy, and nanoparticle tracking analysis. The effects of the EVs from each group on normal human mesangial cells and activation of certain pathways were then investigated. Based on demographic and clinical findings, mean serum creatinine was significantly higher in the FSGS group than the normal healthy control group. The mean size of the EVs in the FSGS group was significantly higher than the healthy control group. The mesangial cells that were challenged with EVs isolated from FSGS patients showed significant upregulation of STAT-3, PCNA, Ki67, and cell proliferation. Our data demonstrate that EVs from FSGS patients stimulate mesangial cell proliferation in association with upregulation of the phospho-STAT-3 pathway. Additional studies are planned to identify the molecular cargo within the EVs from FSGS patients that contribute to the pathogenesis of FSGS.

Unexpected Late Response to Ofatumumab in Adult Post-Transplantation Recurrent Focal Segmental Glomerulosclerosis, Case Report

Idiopathic focal segmental glomerulosclerosis is an important cause of kidney failure in adults, which is associated with a high risk of disease recurrence after transplantation. Plasmapheresis, rituximab, immunoadsorption, and high-dose cyclosporine are used to treat post-transplant recurrent focal segmental glomerulosclerosis (rFSGS). However, the response rate is variable, and few options remain for unresponsive patients. We present a 44-year-old man with an early post-transplant rFSGS. After peritransplant plasmapheresis, rituximab, and abatacept treatments failed, we employed ofatumumab. After 9 months without apparent benefit, we observed an unexpected partial remission thereafter, without severe side effects. Furthermore, remission has been sustained in 30-month follow-up. We believe ofatumumab can be considered an alternative for patients with plasmapheresis and rituximab-resistant post-transplant rFSGS.

Diagnosis and Treatment of Patients With Focal Segmental Glomerulosclerosis/Steroid-Resistant Nephrotic Syndrome: A Delphi Survey

Focal segmental glomerulosclerosis (FSGS) is a histopathologic pattern of podocyte injury with several underlying etiologies and is characterized by segmental scarring that involves part of the glomerulus and a subset of glomeruli sampled on biopsy.1,2 In adults, nephrotic syndrome (NS) is often characteristic of primary (or idiopathic) FSGS. In children, steroid-resistantnephrotic syndrome (SRNS) is an indication for kidney biopsy and most commonly associated with FSGS histologically.3 Available treatments do not always produce complete remission, and patients who do not achieve remission often progress to chronic kidney failure.

Focal Segmental Glomerulosclerosis (FSGS) Progressing to Collapsing Glomerulopathy in Renal Transplant Recipients With and Without COVID-19 Infection.

Collapsing glomerulopathy (CGN) secondary to HIV or COVID-19 infection mainly occurs in patients of African American descent due to APOL-1 gene mutations, but CGN is occasionally reported in white patients. CGNs are rarely reported in renal transplant biopsies and their association with idiopathic focal segmental glomerulosclerosis (FSGS) is unclear. Patient #1 was a 48-year-old Caucasian white man who had a renal transplant 8 years ago and was recently diagnosed with COVID-19 infection. Two weeks post infection, his serum creatinine (SCr) increased to 2.01 mg/dL from a baseline of 1.40 mg/dL, and he developed concomitant nephrotic range proteinuria. The first renal transplant biopsy showed FSGS. Four weeks later, his sCr level increased to 2.65 mg/dL with worsening proteinuria, and a second renal transplant biopsy revealed CGN. Patient #2 was a 32-year-old African American man whose native renal biopsy revealed primary FSGS. He received a renal transplant with initial post-transplant sCr level at 1.17 mg/dL. Four months later, his sCr and protein-to-creatinine ratio began to rise. Sequential biopsies revealed that the patient had developed recurrent FSGS, which progressed to show features of CGN. The CGN was further confirmed in his transplant kidney graft at autopsy later. This is the first case report of CGN in a white renal recipient with COVID-19 infection. The pathologic presentations of FSGS progressing to collapsing FSGS in our 2 renal transplant recipients suggest that FSGS and GGN may share a common pathophysiologic mechanism of podocytopathy.

Outcomes of Different Immunosuppressive Regimen in Adult Biopsy Proven Idiopathic Focal Segmental Glomerulosclerosis: A Retrospective Analysis at a Single Center.

Treatment of focal segmental glomerulosclerosis (FSGS) is frustrating, especially for steroid-resistant FSGS. Different immunosuppressive agents have been used with inconsistent outcome. We analyzed the data in our FSGS patients who, in addition to steroid, were treated with cyclosporine (CYA), cyclophosphamide (CYP), and mycophenolate mofetil (MMF) along with the long-term follow-up. This is a retrospective analysis of 113 patients diagnosed to have FSGS with 11 years' follow-up carried out at The Kidney Center Post Graduate Training institute. Among 113 patients, 51.3% were male with a mean age of 34.4 ± 11.8 standard deviation. Patients who achieved complete remission with steroid alone and steroid with combination of CYA, CYP, and MMF were 38 (26%), 19 (16.8%), and six (5.3%), respectively, similarly those who got partial remission were three (3.6%), five (4.4%), three (2.6%), and eight (7.0%), respectively. The factors which affected the outcome were serum creatinine (SCr), tubulointerstitial fibrosis (TIF), and the treatment. In adjusted analysis, increase in 1 mg of SCr reduces the patient recovery by 56%, while the absence of TIF increases recovery by 80.75%. Taking steroid as reference category, steroid + CYA found 2.03 times more effective as compared with steroid alone. Seven patients developed end-stage renal disease (ESRD) and three died due to disease during the follow-up. CYA comes out as the most effective treatment for steroid-resistant FSGS followed by MMF and CYP. The long-term outcome of all modalities is the same in terms of mortality and developing ESRD. The degree of TIF and renal failure has strong influence on the course of the disease.

Case Report: A Novel Heterozygous Mutation of CD2AP in a Chinese Family With Proteinuria Leads to Focal Segmental Glomerulosclerosis

Idiopathic focal segmental glomerulosclerosis (FSGS) is a relatively frequent kidney disorder that manifest clinically as proteinuria and progressive loss of renal function. Genetic factors play a dominant role in the occurrence of FSGS. CD2-associated protein (CD2AP) is an adapter molecule and is essential for the slit-diaphragm assembly and function. Mutations in the CD2AP gene can contribute to FSGS development. Here, we describe a Chinese family of four generations with unexplained proteinuria. The proband, a 12-year-old boy, was diagnosed as FSGS. Whole-exome sequencing (WES) revealed an unknown frameshift insertion mutation (p.K579Efs*7) of CD2AP gene that leads to a truncation of CD2AP protein. Bioinformatics strategies predicted that the novel mutation was pathogenic. The mutation was absent in either healthy family members or our 200 healthy controls. In summary, we used WES to explore the genetic lesion of FSGS patients and identified a novel mutation in CD2AP gene. This work broadens the mutation spectrum of CD2AP gene and provides data for genetic counseling to additional FSGS patients.

MO247NOVEL DIAGNOSTIC AND THERAPEUTIC TECHNIQUES REVEAL CHANGED METABOLOMIC PROFILE IN RECURRENT FOCAL SEGMENTAL GLOMERULOSCLEROSIS*

Abstract Background and Aims Idiopathic forms of Focal Segmental Glomerulosclerosis (FSGS) are caused by circulating permeability factors, which can lead early recurrence of FSGS and kidney failure after kidney transplantation. In the past three decades, many research endeavors were undertaken to identify these unknown factors. Even though some potential candidates have been recently discussed in the literature, “the” actual factor remains elusive. Therefore, there is an increased demand in FSGS research for the use of novel technologies that can allow us to study FSGS from a yet unexplored angle. Method We used novel treatment options, a personalized in vitro and in vivo assay as well as Raman spectroscopy and mass spectrometry for recurrent FSGS. Results Here, we report the successful treatment of recurrent FSGS in a patient after living related kidney transplantation by removal of circulating factors with CytoSorb apheresis (Fig. 1). Interestingly, the classical published circulating factors were all in normal range in this patient but early disease recurrence in the transplant kidney and immediate response to CytoSorb apheresis were still suggestive for pathogenic circulating factors. To proof the functional effects of the patient’s serum on podocytes and the glomerular filtration barrier we used a podocyte cell culture model and a proteinuria model in zebrafish to detect pathogenic effects on the podocyte’s actin cytoskeleton inducing a functional phenotype (Fig. 2, Fig. 3). We then performed Raman spectroscopy in the <50 kD serum fraction (Fig. 4), on cultured podocytes treated with the FSGS serum (Fig. 5), and in kidney biopsies of the same patient at the time of transplantation and at the time of disease recurrence (Fig. 6). The analysis revealed metabolomic changes in podocytes induced by the FSGS serum as well as in focal glomerular and parietal epithelial cell regions in the FSGS biopsy. Several disturbed Raman spectra were identified in the fractionated serum and metabolome analysis by mass spectrometry detected lipid profiles in the FSGS serum, which corresponded to disturbances in the Raman spectra. Conclusion Our novel innovative analysis reveals changed lipid metabolome profiles associated with idiopathic FSGS that might reflect a new subtype of the disease.

Novel diagnostic and therapeutic techniques reveal changed metabolic profiles in recurrent focal segmental glomerulosclerosis

Idiopathic forms of Focal Segmental Glomerulosclerosis (FSGS) are caused by circulating permeability factors, which can lead to early recurrence of FSGS and kidney failure after kidney transplantation. In the past three decades, many research endeavors were undertaken to identify these unknown factors. Even though some potential candidates have been recently discussed in the literature, “the” actual factor remains elusive. Therefore, there is an increased demand in FSGS research for the use of novel technologies that allow us to study FSGS from a yet unexplored angle. Here, we report the successful treatment of recurrent FSGS in a patient after living-related kidney transplantation by removal of circulating factors with CytoSorb apheresis. Interestingly, the classical published circulating factors were all in normal range in this patient but early disease recurrence in the transplant kidney and immediate response to CytoSorb apheresis were still suggestive for pathogenic circulating factors. To proof the functional effects of the patient’s serum on podocytes and the glomerular filtration barrier we used a podocyte cell culture model and a proteinuria model in zebrafish to detect pathogenic effects on the podocytes actin cytoskeleton inducing a functional phenotype and podocyte effacement. We then performed Raman spectroscopy in the < 50 kDa serum fraction, on cultured podocytes treated with the FSGS serum and in kidney biopsies of the same patient at the time of transplantation and at the time of disease recurrence. The analysis revealed changes in podocyte metabolome induced by the FSGS serum as well as in focal glomerular and parietal epithelial cell regions in the FSGS biopsy. Several altered Raman spectra were identified in the fractionated serum and metabolome analysis by mass spectrometry detected lipid profiles in the FSGS serum, which were supported by disturbances in the Raman spectra. Our novel innovative analysis reveals changed lipid metabolome profiles associated with idiopathic FSGS that might reflect a new subtype of the disease.

APOL1 risk variants and the development of HIV-associated nephropathy.

HIV-associated nephropathy (HIVAN) remains a concern among untreated HIV patients, notably of African descent, as patients can reach end-stage renal disease within 3years. Two variants (G1 and G2) of the APOL1 gene, common in African populations to protect against African sleeping sickness, have been associated with an increased risk of several glomerular disorders including HIVAN, hypertension-attributed chronic kidney disease, and idiopathic focal segmental glomerulosclerosis and are accordingly named renal risk variants (RRVs). This review examines the mechanisms by which APOL1 RRVs drive glomerular injury in the setting of HIV infection and their potential application to patient management. Innate antiviral mechanisms activated by chronic HIV infection, especially those involving type 1 interferons, are of particular interest as they have been shown to upregulate APOL1 expression. Additionally, the downregulation of miRNA 193a (a repressor of APOL1) is also associated with the upregulation of APOL1. Interestingly, glomerular damage affected by APOL1 RRVs is caused by both loss- and gain-of-function changes in the protein, explicitly characterizing these effects. Their intracellular localization offers a further understanding of the nuances of APOL1 variant effects in promoting renal disease. Finally, although APOL1 variants have been recognized as a critical genetic player in mediating kidney disease, there are significant gaps in their application to patient management for screening, diagnosis, and treatment.

Multidimensional inflammatory and immunological endotypes of idiopathic focal segmental glomerulosclerosis and their association with treatment outcomes.

ObjectivesIdiopathic focal segmental glomerulosclerosis (FSGS) has been linked to immunological and inflammatory response dysregulations. The aim of this study was to find endotypes of FSGS patients using a cluster (CL) analysis based on inflammatory and immunological variables, and to analyse whether a certain endotype is associated with response to treatment with corticosteroids.MethodsThis prospective observational study included patients with idiopathic FSGS diagnosed by kidney biopsy. Serum levels of soluble interleukin (IL)-1 receptor, tumoural necrosis factor alpha, Interferon gamma (IFNγ), IL-6, IL-17, IL-12, IL-23, IL-13, IL-4, IL-5, IL-6, haemopexin (Hx), haptoglobin (Hgl), soluble urokinase-type plasminogen activator receptor (suPAR) and urinary CD80 (uCD80) were measured with enzyme-linked immunosorbent assay or nephelometry. T-helper lymphocyte populations and T-regulatory lymphocytes were analysed by flow cytometry. A factorial analysis followed by a k-means CL analysis was performed.ResultsA total of 79 FSGS patients were included. Three CLs were identified. CL1 (27.8%) included IL-12, IL-17, IL-23 and a T helper 17 (Th17) pattern. CL2 (20.2%) included IL-4, IL-5, IL-13, immunoglobulin E and Th2 pattern. CL3 (51.8%) included IL-6, Hx, Hgl, suPAR and uCD80. There were no differences in age, gender, kidney function, albumin or proteinuria among CLs. About 42/79 patients (53.1%) showed cortico-resistance. The prevalence of cortico-resistance was significantly lower in CL2 (4/16, 25%) than in CL1 (16/26, 72.7%) and CL3 (22/41, 53.7%) (P = 0.018), with no significant differences between CLs 1 and 3 (P = 0.14).ConclusionsPatients with FSGS and indistinguishable clinical presentation at diagnosis were classified in three distinct CLs according to predominant Th17, Th2 and acute inflammatory responses that display differences in clinical response to treatment with corticosteroids.

Novel in vitro assays to detect circulating permeability factor(s) in idiopathic focal segmental glomerulosclerosis.

Many patients with idiopathic focal segmental glomerulosclerosis (FSGS) develop recurrence of proteinuria after kidney transplantation (TX). Although several circulating permeability factors (CPFs) responsible for recurrence have been suggested, there is no consensus. To facilitate CPF identification and predict recurrence after TX, there is a need for robust methods that demonstrate the presence of CPFs. Cultured human podocytes (hPods) and human and mouse glomerular endothelial cells (ciGEnC, mGEnC) were exposed to plasmas of FSGS patients with presumed CPFs, and of (disease) controls. A visual scoring assay and flow cytometry analysis of side scatter were used to measured changes in cellular granularity after exposure to plasma. Nine out of 13 active disease plasmas of 10 FSGS patients with presumed CPFs induced granularity in hPod in a dose- and time-dependent manner. Corresponding remission plasmas induced no or less granularity in hPod. Similar results were obtained with ciGEnC and mGEnC, although induced granularity was less compared with hPod. Notably, foetal calf serum, healthy plasma and a remission plasma partially blocked FSGS plasma-induced hPod granularity. We developed a novel assay in which active disease, presumably CPF-containing, FSGS plasmas induced granularity in cultured hPod. Our results may indicate the presence of CPF inhibitor(s) in healthy and remission plasma. We suggest the presence of a delicate balance between CPF and a CPF inhibitory factor, which is disturbed in patients with active disease. Our novel assays can be applied in future research to identify CPF and CPF inhibitors, and possibly to predict recurrence after TX.

Challenges in primary focal segmental glomerulosclerosis diagnosis: from the diagnostic algorithm to novel biomarkers.

Primary or idiopathic focal segmental glomerulosclerosis (FSGS) is a kidney entity that involves the podocytes, leading to heavy proteinuria and in many cases progresses to end-stage renal disease. Idiopathic FSGS has a bad prognosis, as it involves young individuals who, in a considerably high proportion (∼15%), are resistant to corticosteroids and other immunosuppressive treatments as well. Moreover, the disease recurs in 30–50% of patients after kidney transplantation, leading to graft function impairment. It is suspected that this relapsing disease is caused by a circulating factor(s) that would permeabilize the glomerular filtration barrier. However, the exact pathologic mechanism is an unsettled issue. Besides its poor outcome, a major concern of primary FSGS is the complexity to confirm the diagnosis, as it can be confused with other variants or secondary forms of FSGS and also with other glomerular diseases, such as minimal change disease. New efforts to optimize the diagnostic approach are arising to improve knowledge in well-defined primary FSGS cohorts of patients. Follow-up of properly classified primary FSGS patients will allow risk stratification for predicting the response to different treatments. In this review we will focus on the diagnostic algorithm used in idiopathic FSGS both in native kidneys and in disease recurrence after kidney transplantation. We will emphasize those potential confusing factors as well as their detection and prevention. In addition, we will also provide an overview of ongoing studies that recruit large cohorts of glomerulopathy patients (Nephrotic Syndrome Study Network and Cure Glomerulonephropathy, among others) and the experimental studies performed to find novel reliable biomarkers to detect primary FSGS.

Basic fibroblast growth factors as a biomarker of focal segmental glomerulosclerosis in HIV-positive and HIV-negative children

Background. HIV infection can lead to the development of HIV-associated nephropathy (HIVAN) with the majority of patients progressing to end-stage kidney disease. Previous studies have recognised basic fibroblast growth factor (bFGF) as a biomarker for HIVAN, since significant levels of bFGF low-affinity receptors have been found in the kidneys of HIV-infected children. Objective. To assess the association between bFGF and kidney disease in the development of focal segmental glomerulosclerosis (FSGS) in HIV-positive and negative children. Methods. The study group consisted of 31 children; HIVAN ( n =11) and idiopathic FSGS ( n =20). The control group consisted of both HIV-positive ( n =20) and HIV-negative ( n =20) children with no kidney disease. Serum samples from all patients in both the study and control groups were analysed for bFGF. Results . The concentration of bFGF was higher, in comparison with idiopathic FSGS children, in HIVAN children ( p =0.0167). There was also a significant elevation of serum bFGF levels in children with HIVAN when compared with HIV-positive ( p =0.0288) and HIV-negative ( p =0.0043) control groups. Conclusion. This study demonstrated statistically significant differences between bFGF levels in children with HIVAN and a control group, although it failed to distinguish significant differences in bFGF levels between HIVAN and idiopathic FSGS children.

The effect of APOL1 risk variants on emergent outcomes in kidney disorders: A meta-analysis of individual participant data

Abstract. Kidney diseases associated with APOL1 polymorphisms are human immunodeficiency virus-associated nephropathy, idiopathic focal segmental glomerulosclerosis, hypertension-attributed chronic kidney disease, lupus nephritis and sickle cell nephropathy. This research aimed to investigate the risk of genetic variants on disease contribution.&#x0D; Methods. In this individual participant data meta-analysis, eighteen patients with kidney dysfunction and at risk of APOL1 genotype were investigated. Clinical features, laboratory data at initial presentation, management and outcomes were collected. The paper has written based on searching PubMed Central and Google Scholar to identify potentially relevant articles. Median, percentage, mean ± standard deviation (SD), two-tailed t and chi-square tests were used for statistical analyses. Moreover, relative risk, odds ratio for statistical analyses were used.&#x0D; Results: The average age of patients at the time of diagnosis in APOL1-associated kidney disorders was 41.09 ± 20.63 years (ranging from 8 years to 70 years). Relative risk for kidney failure and persistent hemodialysis therapy in APOL1-associated nephropathy patients with renal risk variants (RRVs) were assessed 1.13 and odds ratio of 1.5 with 95% CI of 0.08-26.86 and the value of 0.0764 by chi-square test but there was no significant statistical result in this research (p-value of 0.782). The relative risk for patients of allograft failure with RRVs was assessed 1,0 odds ratio of 1,0 95% CI of 0.06-15.99 and p-value of 0.81.&#x0D; Conclusion: The present study revealed the risk and odds of APOL1 gene effect on the onset of kidney failure with replacement therapy in patients at risk of APOL1 genotype but results were not significant statistically. Future clinical research is required for investigating APOL1 gene effect on non-African ancestry.

P0504FACTORS ASSOCIATED WITH THE LONG-TERM RENAL OUTCOME OF IDIOPATHIC FOCAL SEGMENTAL GLOMERULOSCLEROSIS WITH NEPHROTIC SYNDROME

Abstract Background and Aims In the treatment of idiopathic focal segmental glomerulosclerosis (FSGS) with nephrotic syndrome, the remission of proteinuria is considered to be an important goal. The partial remission of proteinuria improves renal survival, whereas it may progressively reduce the renal function. A study searched for a novel partial remission more accurately reflecting the long-term renal outcome. The goal of proteinuria reduction for improving the renal prognosis remains to be clarified. We examined factors associated with the long-term renal outcome of idiopathic FSGS. Method Of 148 patients with FSGS diagnosed based on kidney biopsy between 1981 and 2018, a retrospective cohort study was conducted involving 33 who had undergone immunosuppressive therapy for nephrotic syndrome, and had been followed-up for ≥1 year, excluding those with secondary FSGS. We examined the renal prognosis, regarding a 50% decrease in the estimated glomerular filtration rate (eGFR) as an outcome. We calculated the rate of decrease in the urinary protein level 4 and 8 months after the start of treatment, and estimated the rate of decrease associated with renal hypofunction using ROC analysis. Based on the results of ROC analysis, Cox’s proportional hazard analysis was performed using factors contributing to renal hypofunction as covariates. Results Concerning the background of the 33 patients, the mean follow-up period was 11.4 years, and there were 24 males. The mean age was 49.8 years, and the mean blood pressure was 100.5 mmHg. The mean urinary protein level, albumin (Alb) level, eGFR, and total cholesterol (TCho) level were 7.4 g/day, 2.1 g/dL, 44.3 mL/min/1.73 m2, and 369 mg/dL, respectively. Corticosteroid therapy was selected in 21 patients, whereas it was combined with steroid pulse therapy in 12. The daily dose of prednisolone was 37.3 mg. On ROC analysis, the rate of decrease in the urinary protein level after 4 months was 83.1% (AUC: 0.74, sensitivity: 0.80, specificity: 0.74), and that after 8 months was 85.7% (AUC: 0.78, sensitivity: 0.90, specificity: 0.65). Cox’s proportional hazard analysis, in which the data were adjusted with the sex, blood pressure, urinary protein level at the start of treatment, Alb level, eGFR, and treatment methods, showed that the rate of decrease in the urinary protein level after 4 months was significantly correlated with renal hypofunction: after 4 months: hazard ratio, 0.19 (95%CI: 0.04-0.77); p=0.0202; after 8 months: hazard ratio, 0.34 (95%CI: 0.05-1.37); p=0.1359. Conclusion In the treatment of idiopathic FSGS with nephrotic syndrome, the rate of decrease in the urinary protein level 4 months after the start of treatment was correlated with the long-term renal outcome.

P0372RITUXIMAB IN IDIOPATHIC FOCAL SEGMENTAL GLOMERULOSCLEROSIS OF THE ADULT: A MULTICENTRE RETROSPECTIVE SURVEY OF 31 PATIENTS

Abstract Background and Aims Idiopathic Focal Segmental Glomerulosclerosis (FSGS) is a rare glomerulonephritis often complicated by a chronic relapsing course frequently characterized by dependency or resistance to immunosuppressive treatment. Moreover, about half of the patients with active disease would develop end-stage renal disease within 10 years from the diagnosis, highlighting the need of novel therapeutic approaches. Rituximab (RTX), a chimeric monoclonal antibody against CD20, showed promising results in pediatric steroid-dependent/frequently relapsing FSGS and in post-transplantation recurrence. However, evidence about its role in the FSGS of the adult is still lacking with small case series suggesting conflicting results. In this study we assess the efficacy of RTX in the largest cohort of adults with FSGS currently available in literature. Methods Adults with biopsy proven idiopathic FSGS treated with RTX were retrospectively identified among several Italian nephrology units. Response to RTX was evaluated at 3, 6, 12 months and, when available, during the long-term follow-up. A positive response (POR) was defined as: (1) proteinuria &amp;lt;3.5 g/die with a decrease &amp;gt;50% compared to baseline, (2) stable renal function (3) decreased or stable dose of glucocorticoids and other immunosuppressants. Severe Adverse Events (SAEs) have been recorded. Results 31 patients have been identified: 18 steroid-dependent, 11 steroid-resistant, and 2 patients with major contraindication to steroid therapy. RTX has been administered at a median of 87 months (IQR 54–96) from the diagnoses using heterogeneous schedules of administration. Overall, the POR rate at 6 months was 52% (steroid-dependent=69%; steroid-resistant=22%). At univariate analyses, POR to RTX at 6 months was associated to the steroid-dependent status (p=0.0347) and a proteinuria at RTX &amp;lt;5 g/die (p=0.0173); a trend towards better response was observed in patients with IgG at RTX &amp;lt;500 mg/dl (p=0.0774). Over the first year of follow-up, the proteinuria and serum albumin significantly improved (respectively, p=0.0021 and p=0.0277 at 12 months), while serum creatinine remained stable (figure). Among treated patients, the median dose of prednisone decreased from 15 mg/die (IQR 12.5–25) at baseline to 10 mg/die (IQR 5–15) at 12 months, while the proportion of patients free from glucocorticoids respectively increased from 42% to 54%. Six patients have been retreated within a year since the first RTX: of these only the 2 patients who have experienced a POR to the first administration obtained a further POR after retreatment. After the 12th month, 11 patients have been followed for a median time of 17 months (IQR 15–33.5): of the 5/11 with a POR at the 12th month, 2/5 maintained a POR without needing further immunosuppression, 2/5 maintained a POR with a pre-emptive RTX based maintenance treatment, 1/5 experienced a relapse successfully managed with RTX needing then a pre-emptive RTX based maintenance therapy able to allow a persistent POR. Overall, 9 SAEs have been recorded with requirement of hospital admission for clinical deterioration being the most frequent. Conclusion RTX may be an option in the FSGS of the adult, especially in the steroid-dependent patients and the ones with less severe nephrotic syndrome. In the responders, a RTX based maintenance therapy may be required.

Combination of High-Dose Intravenous Cyclosporine and Plasma Exchange Treatment Is Effective in Post-Transplant Recurrent Focal Segmental Glomerulosclerosis: Results of Case Series

BackgroundIdiopathic focal segmental glomerulosclerosis (FSGS) commonly recurs in the early post-transplant period. The treatment protocols and results are conflictive in recurrent FSGS. We aimed to present the results of our treatment protocol and basic approach to the disease recurrences. MethodsThis prospective, single-center study was conducted between the years 2015 and 2018. Twelve patients who fit completely the diagnosis of idiopathic FSGS by clinical, laboratory, and biopsy findings were included. A specific treatment protocol which consists of plasma exchange and high dose intravenous cyclosporine was delivered to the patients independently of induction protocols. Twenty-four months of outcomes of graft functions were evaluated. ResultsNine patients completed the treatment protocol and were documented for evaluation. All patients achieved a complete or partial remission in an average 24 months of follow-up period. ConclusionIdiopathic FSGS is more commonly recurrent than thought to be. The early detection of proteinuria is crucial because the administration of a plasma exchange–based treatment protocol can reverse proteinuria. We think our treatment protocol is a well-established, efficient, and safe choice for post-transplant recurrent FSGS in adults.

A misprocessed form of Apolipoprotein A-I is specifically associated with recurrent Focal Segmental Glomerulosclerosis

Apolipoprotein A-Ib (ApoA-Ib) is a high molecular weight form of Apolipoprotein A-I (ApoA-I) found specifically in the urine of kidney-transplanted patients with recurrent idiopathic focal segmental glomerulosclerosis (FSGS). To determine the nature of the modification present in ApoA-Ib, we sequenced the whole APOA1 gene in ApoA-Ib positive and negative patients, and we also studied the protein primary structure using mass spectrometry. No genetic variations in the APOA1 gene were found in the ApoA-Ib positive patients that could explain the increase in its molecular mass. The mass spectrometry analysis revealed three extra amino acids at the N-Terminal end of ApoA-Ib that were not present in the standard plasmatic form of ApoA-I. These amino acids corresponded to half of the propeptide sequence of the immature form of ApoA-I (proApoA-I) indicating that ApoA-Ib is a misprocessed form of proApoA-I. The description of ApoA-Ib could be relevant not only because it can allow the automated analysis of this biomarker in the clinical practice but also because it has the potential to shed light into the molecular mechanisms that cause idiopathic FSGS, which is currently unknown.

Rituximab use in adult glomerulopathies and its rationale

Glomerulopathies are one of the leading causes of end-stage renal disease. In the last years, clinical research has made significant contributions to the understanding of such conditions. Recently, rituximab (RTX) has appeared as a reasonably safe treatment. The Kidney Disease: Improving Global Outcomes guidelines (KDIGO) recommended RTX only as initial treatment in antineutrophil cytoplasm antibody associated vasculitis (AAV) and in non-responders patients with lupus nephritis (LN), but these guidelines have not been updated since 2012. Nowadays, RTX seems to be at least as effective as other immunosuppressive regimens in idiopathic membranous nephropathy (IMN). In minimal-change disease, (MCD) this drug might allow a long-lasting remission period in steroid-dependent or frequently relapsing patients. Preliminary results support the use of RTX in patients with pure membranous LN and immunoglobulin-mediated membranoproliferative glomerulonephritis (MPGN), but not in patients with class III/IV LN or complement-mediated MPGN. No conclusion can be drawn in idiopathic focal segmental glomerulosclerosis (FSGS) and anti-glomerular basement membrane antibody glomerulonephritis (anti-GBM GN) because studies are small, heterogeneous, and scarce. Lastly, immunosuppression including RTX is not particularly useful in IgA nephropathy. This review presents the general background, outcomes, and safety for RTX treatment in different glomerulopathies. In this regard, we describe randomized controlled trials (RCTs) performed in adults, whenever possible. A literature search was performed using clinicaltrials.gov and PubMed.