UNASSIGNED: Idiopathic nephrotic syndrome (INS) is a heterogenous disease and current classification is based on observational responses to therapies or kidney histology. The National Unified Renal Translational Research Enterprise (NURTuRE)-INS cohort aims to facilitate novel ways of stratifying INS patients to improve disease understanding, therapeutics and design of clinical trials.
UNASSIGNED: NURTuRE-INS is a prospective cohort study of children and adults with INS in a linked biorepository. All recruits had at least one sampling visit collecting serum, plasma, urine and blood for RNA and DNA extraction, frozen within 2 hours of collection. Clinical histology slides and biopsy tissue blocks were also collected.
UNASSIGNED: A total of 739 participants were recruited from 23 centres to NURTuRE-INS, half of whom were diagnosed in childhood [n = 365 (49%)]. The majority were white [n = 525 (71%)] and the median age at recruitment was 32 years (interquartile range 12-54). Steroid-sensitive nephrotic syndrome (SSNS) was the most common clinical diagnosis [n = 518 (70%)]. Of patients diagnosed in childhood who underwent a kidney biopsy, for SSNS (n =103), 76 demonstrated minimal change disease (MCD), whereas for steroid-resistant nephrotic syndrome (n =80), 21 had MCD. Almost all patients diagnosed in adulthood had a kidney biopsy [n = 352 (94%)]; 187 had MCD and 162 had focal segmental glomerulosclerosis.
UNASSIGNED: NURTuRE-INS is a prospective cohort study with high-quality biosamples and longitudinal data that will assist research into the mechanistic stratification of INS. Samples and data will be available through a Strategic Access and Oversight Committee.

Focal segmental glomerulosclerosis (FSGS), a clinicopathological condition characterized by nephrotic-range proteinuria, has a high risk of progression to end-stage renal disease (ESRD). Meanwhile, the recurrence of FSGS after renal transplantation is one of the main causes of graft loss. The diagnosis of recurrent FSGS is mainly based on renal puncture biopsy transplants, an approach not widely consented by patients with early mild disease. Therefore, there is an urgent need to find definitive diagnostic markers that can act as a target for early diagnosis and intervention in the treatment of patients. In this review, we summarize the domestic and international studies on the pathophysiology, pathogenesis and earliest screening methods of FSGS and describe the functions and roles of specific circulating factors in the progression of early FSGS, in order to provide a new theoretical basis for early diagnosis of FSGS recurrence, as well as aid the exploration of therapeutic targets.

BACKGROUND: Minimal Change Disease (MCD) and Focal Segmental Glomerulosclerosis (FSGS) are a spectrum of disease causing the nephrotic syndrome (NS), characterised by proteinuria with debilitating oedema, as well as a high risk of venous thromboembolic disease and infection. Untreated, 50-60% patients with FSGS progress to end stage kidney disease after 5 years. These diseases respond to immunosuppression with high dose glucocorticoids, but 75% will relapse as the glucocorticoids are withdrawn, leading to significant morbidity associated with prolonged use. In children, the B cell depleting monoclonal antibody rituximab reduces relapse risk, but this drug has not been tested in randomised controlled trial in adults.
METHODS: 130-150 adults with new or relapsing MCD/FSGS, from UK Renal Units, are being randomised to receive either rituximab (two 1 g infusions two weeks apart) or placebo. Partipicipants are recruited when they present with nephrosis, and all are treated with glucocorticoids as per KDIGO guidelines. Once in remission, prednisolone is withdrawn according to a pre-specified regimen. If in remission at 6 months, participants receive a further dose of trial drug. If they relapse, they are unblinded, and if they have received placebo, they are offered open label rituximab with protocolised prednisolone as in the main phase of the trial. The primary end point is time from remission to relapse. A number of secondary endpoints will be assessed including the effect of rituximab on: (1) NHS and societal resource use and hence cost: (2) safety: (3) other measures of efficacy, such as achievement of partial and complete remission of NS and the preservation of renal function: (4) health status of participant.
BACKGROUND: TURING received ethical approval on 14 Jun 2019 - REC reference: 19/LO/0738. It is registered on EudraCT, with ID number: 2018-004611-50, with a start date of 2019-06-14.

Collapsing glomerulopathy (CG) is a pattern of kidney injury characterized by segmental or global collapse of the glomerular tuft associated with overlying epithelial cell hyperplasia. Although CG may be idiopathic, a wide range of etiologies have been identified that can lead to this pattern of injury. Recent advances have highlighted the role of inflammatory and interferon signaling pathways and upregulation of apolipoprotein L1 (APOL1) within podocytes in those carrying a high-risk APOL1 genotype. In this review, we describe the etiology, pathogenesis, pathology, and clinical course of CG, focusing on nonviral etiologies. We also describe current treatments and explore potential therapeutic options targeting interferon/APOL1 pathways in CG.

Podocytes are epithelial cells lining the outer surface of the renal glomerular capillaries and they play a pivotal role in maintaining the structural and functional integrity of the glomerular filtration barrier. Podocytes react to injury in various ways and any injury to these highly specialized cells can progress to podocyte dysfunction, resulting in a group of proteinuric renal diseases called podocytopathies. Podocytopathies include a wide spectrum of primary and secondary kidney diseases, including minimal change disease, diffuse mesangial sclerosis, focal segmental glomerulosclerosis, collapsing glomerulopathy, diabetic, membranous and lupus nephropathies. Etiologically, they can be idiopathic, genetic or secondary to infections and drugs, metabolic diseases, hemodynamic factors or associated with various immune and non-immune systemic diseases. This manuscript provides a basic understanding of podocyte structure, causes of podocyte injury, response to the injury and the subsequent progression to podocytopathies. The pathogenesis of these diseases is set around podocytes. The clinical and morphological manifestations, the commonality and heterogeneity of these podocytopathies are also discussed. As our knowledge of podocyte biology improves, so will our treatment avenues with a more podocyte-centric personalized approach.

Primary glomerulonephritis comprises several renal-limited diseases that can cause haematoproteinuria, chronic kidney disease, nephrosis and end stage kidney disease. The most common of these are IgA nephropathy (IgAN), primary membranous nephropathy (PMN), Focal Segmental Glomerulosclerosis (FSGS) and Minimal Change Disease (MCD). Although rare, these diseases cause a significant burden to health care systems, given the high cost of treating End Stage Kidney Disease (ESKD) with dialysis or transplantation. Until recently, the pathogenesis of primary gloerulonephritis has remained obscure. However, recent advances in understanding of how these diseases evolve has led to the introduction of novel therapeutic agents. Trials are underway or have recently completed that have huge implications for the standard of care for the primary glomerulonephritidies, and should dramatically reduce the number of patients who progress onto end stage kidney disease. This article reviews the international Kidney Disease Improving Global Outcomes (KDIGO) guidelines for the treatment of IgAN, PMN, FSGS and MCD, as well as recent research on pathogenesis and treatment.

BACKGROUND: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease caused by the expansion of GGC repeats in the 5\'-untranslated region (5\'-UTR) of NOTCH2NLC. Although increasing evidence suggests that NIID affects various organs, its association with renal involvement remains unclear. We studied the genetic background of a family with NIID, in which four of five members presented with proteinuria as the initial manifestation. The renal pathology of three patients was diagnosed as focal segmental glomerulosclerosis (FSGS) at a previous hospital. These patients also presented with tremors, retinal degeneration, and episodic neurological events. Finally, one patient exhibited reversible bilateral thalamic high-intensity signal changes on diffusion-weighted imaging during episodic neurological events.
METHODS: Exome sequencing (ES) and nanopore long-read whole-genome sequencing (LR-WGS) were performed on the index case, followed by nanopore target sequencing using Cas9-mediated PCR-free enrichment and methylation analysis.
RESULTS: ES revealed no candidate variants; however, nanopore LR-WGS in the index case revealed expansion of short tandem repeats (STR) in NOTCH2NLC. Subsequent nanopore target sequencing using Cas9-mediated PCR-free enrichment showed STR expansion of NOTCH2NLC in an affected sibling and asymptomatic father. Methylation analysis using nanopore data revealed hypermethylation of the expanded allele in the asymptomatic father and partial hypermethylation in a mildly symptomatic sibling, whereas the expanded allele was hypomethylated in the index case.
CONCLUSIONS: This investigation expands the clinical spectrum of NIID, suggesting that STR expansion of NOTCH2NLC is a cause of renal diseases, including FSGS.

UNASSIGNED: Focal segmental glomerulosclerosis (FSGS) is a prevalent glomerular disease that often leads to nephrotic syndrome. It is characterized by consolidating a portion of the glomerular capillary tuft connected to Bowman\'s capsule. This retrospective cohort study aimed to determine the demographic characteristics, risk factors, and prognostic indicators associated with FSGS in Shiraz, Iran.
UNASSIGNED: The study included 53 primary FSGS patients aged over 18 years who were referred to clinics affiliated with Shiraz University of Medical Sciences. Data were collected through a comprehensive data-gathering sheet encompassing demographic information, medical history, laboratory test results, and histopathological findings. Statistical analysis was performed using SPSS 18, considering a significance level of p<0.05.
UNASSIGNED: A five-year follow-up was conducted on the 53 patients, with the mean age of 41.0±13.3 years. The most common FSGS variants observed were \"not otherwise specified\" (NOS, 13.2%) and tip variant (7.5%). Older patients exhibited higher disease activity, whereas remission rates were higher among younger individuals (P=0.012). Patients achieving remission had lower creatinine and Pro/Cr ratios and higher glomerular filtration rates (p<0.05). Treatment involving a combination of corticosteroids and mycophenolate mofetil showed a significant correlation with remission (P=0.036).
UNASSIGNED: Older patients with higher creatinine levels, higher Pro/Cr ratios, and lower glomerular filtration rates at disease onset may require more aggressive treatment. Combination therapy with mycophenolate mofetil and corticosteroids yields better outcomes, leading to increased remission rates. These findings provide valuable insights for managing FSGS patients.

BACKGROUND: Recurrence of focal segmental glomerulosclerosis (FSGS) or steroid-resistant nephrotic syndrome (SRNS) after kidney transplant leads to significant morbidity and potentially earlier allograft loss. To date however, reported rates, risk factors and treatment outcomes have varied widely.
METHODS: We applied computational phenotypes to a multicenter aggregation of electronic health records data from 7 large pediatric health systems in the USA, to identify recurrence rates, risk factors, and treatment outcomes. We refined the data collection by chart review.
RESULTS: From > 7 million patients, we compared children with primary FSGS/SRNS who received a kidney transplant between 2009 and 2020 and who either developed recurrence (n = 67/165; 40.6%) or did not (n = 98/165). Serum albumin level at time of transplant was significantly lower and recipient HLA DR7 presence was significantly higher in the recurrence group. By 36 months post-transplant, complete remission occurred in 58.2% and partial remission in 17.9%. Through 6 years post-transplant, no remission after recurrence was associated with an increased risk of allograft loss over time (p < 0.0001), but any remission showed similar allograft survival and function decline to those with no recurrence. Since treatments were used in non-random fashion, using spline curves and multivariable non-linear analyses, complete + partial remission chance was significantly higher with greater plasmapheresis sessions, CTLA4-Ig doses or LDL-apheresis sessions. Only treatment with anti-CD20, CTLA4-Ig agents, or LDL-apheresis sessions were associated with complete remission. Excluding 25 patients with mutations did not significantly change our results.
CONCLUSIONS: Our contemporary high-risk cohort had higher favorable response rates than most prior reports, from combinations of agents.

Mutations in the human INF2 gene cause autosomal dominant focal segmental glomerulosclerosis (FSGS)-a condition characterized by podocyte loss, scarring, and subsequent kidney degeneration. To understand INF2-linked pathogenicity, we examined the effect of pathogenic INF2 on renal epithelial cell lines and human primary podocytes. Our study revealed an increased incidence of mitotic cells with surplus microtubule-organizing centers fostering multipolar spindle assembly, leading to nuclear abnormalities, particularly multi-micronucleation. The levels of expression of exogenous pathogenic INF2 were similar to those of endogenous INF2. The aberrant nuclear phenotypes were observed regardless of the expression method used (retrovirus infection or plasmid transfection) or the promoter (LTR or CMV) used, and were absent with exogenous wild type INF2 expression. This indicates that the effect of pathogenic INF2 is not due to overexpression or experimental cell manipulation, but instead to the intrinsic properties of pathogenic INF2. Inactivation of the INF2 catalytic domain prevented aberrant nuclei formation. Pathogenic INF2 triggered the translocation of the transcriptional cofactor MRTF into the nucleus. RNA sequencing revealed a profound alteration in the transcriptome that could be primarily attributed to the sustained activation of the MRTF-SRF transcriptional complex. Cells eventually underwent mitotic catastrophe and death. Reducing MRTF-SRF activation mitigated multi-micronucleation, reducing the extent of cell death. Our results, if validated in animal models, could provide insights into the mechanism driving glomerular degeneration in INF2-linked FSGS and may suggest potential therapeutic strategies for impeding FSGS progression.