Individualizing Treatment of Steroid-Resistant Nephrotic Syndrome: Registries to the Fore

Network Pharmacology and Molecular Docking Validation to Explore the Pharmacological Mechanism of Zhuling Decoction against Nephrotic Syndrome

BACKGROUND

In recent years, the incidence and prevalence of Nephrotic Syndrome (NS) have been increasing. Zhuling Decoction (ZLD), a classical Chinese medicine, has been clinically proven to be effective for the treatment of NS. However, its underlying mechanism and pharmacodynamic substances remain unclear.

OBJECTIVE

This study aimed to explore the mechanism of action and chemical components of ZLD against NS using network pharmacology and molecular docking.

METHODS

Traditional Chinese Medicine Systems Pharmacology (TCMSP), Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicines (BATMAN-TCM), and SwissTargetPrediction databases were used to screen the principal ingredients and the associated targets of ZLD. NS-related targets were obtained from the Online Mendelian Inheritance in Man (OMIM), GeneCards, Therapeutic Target Database (TTD), and Drugbank databases. Shared targets were derived by the intersection of ZLD- and NS-associated targets. Protein-interaction relationships were analyzed using the STRING database and Cytoscape. A visualized drug-active compound-target network of ZLD was established using Cytoscape. Analyses of gene enrichment were performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) methods by the Database for Annotation, Visualization, and Integrated Discovery (DAVID) database. Molecular docking was performed to assess the binding activity between active components and hub targets.

RESULTS

Polyporusterone E, cerevisterol, alisol B, and alisol B 23-acetate were the primary potential ingredients of ZLD. HMGCR, HSD11B1, NOS2, NR3C1, and NR3C2 were the hub targets of ZLD against NS. Molecular docking showed that polyporusterone E, cerevisterol, and alisol B had high binding activities with targets HMGCR, HSD11B1, and NOS2.

CONCLUSION

In summary, this study suggests that the main active compounds (polyporusterone E, cerevisterol, alisol B) may have important roles for ZLD acting against NS by binding to hub targets (HMGCR, HSD11B1, and NOS2) and modulating PI3K-Akt, Ras, MAPK, and HIF-1 signaling pathways.

Use of Rituximab in Childhood Idiopathic Nephrotic Syndrome

Rituximab is an established therapy in children with idiopathic nephrotic syndrome to sustain short- to medium-term disease remission and avoid steroid toxicities. Recent trials focus on its use as a first-line agent among those with milder disease severity. Rituximab is used in multidrug refractory nephrotic syndrome and post-transplant disease recurrence, although the evidence is much less substantial. Available data suggest that the treatment response to rituximab depends on various patient factors, dosing regimen, and the concomitant use of maintenance immunosuppression. After repeated treatments, patients are found to have an improving response overall with a longer relapse-free period. The drug effect, however, is not permanent, and 80% of patients eventually relapse and many will require an additional course of rituximab. This underpins the importance of understanding the long-term safety profile on repeated treatments. Although rituximab appears to be generally safe, there are concerns about long-term hypogammaglobulinemia, especially in young children. Reliable immunophenotyping and biomarkers are yet to be discovered to predict treatment success, risk of both rare and severe side effects, e.g. , persistent hypogammaglobulinemia, and guiding of redosing strategy. In this review, we highlight recent advances in the use of rituximab for childhood nephrotic syndrome and how the therapeutic landscape is evolving.

Efficacy and Safety of Mizoribine in comparison with Cyclophosphamide for Treatment of Refractory Nephrotic Syndrome: Protocol for a Multi-center, Controlled, Open-label, Randomized Controlled Trial (Preprint)

BACKGROUND

Nephrotic syndrome that is resistant to steroidal therapy is termed refractory nephrotic syndrome (RNS), a condition that is associated with an increased risk of end-stage renal disease (ESRD). Immunosuppressants are utilized to treat RNS, however prolonged may lead to significant adverse effects. Mizoribine (MZR) is a novel agent used in long-term immunosuppressive therapy that has few adverse effects, but data on its long-term use in patients with RNS are unavailable.

OBJECTIVE

We propose a trial to examine the efficacy and safety of MZR compared to cyclophosphamide (CYC) in Chinese adult patients with RNS.

METHODS

This is a multi-center, randomized, controlled interventional study with a screening phase (1 week) and a treatment phase (52 weeks). This study was reviewed and approved by the Medical Ethics Committees of all 34 medical centers. Patients with RNS consented to participation, and were enrolled and randomized into an MZR group or a CYC group (1:1 ratio), with each group receiving tapering doses of oral corticosteroids. Participants were assessed for adverse effects and collection of laboratory results at 8 visits during the treatment phase on week-4, week-8, week-12, week-16, week-20, week-32, week-44, and week-52 (exit visit). Participants were able to withdraw voluntarily and investigators were required to remove patients when there were safety concerns or deviations from protocol.

RESULTS

The study started in November 2014, and was completed in March 2019. A total of 239 participants from 34 hospitals in China were enrolled. Data analysis is completed. The results are waiting to be finalized by Center for Drug Evaluation.

CONCLUSIONS

The purpose of the current study is to evaluate the efficacy and safety of MZR in comparison with CYC for treatment of RNS in Chinese adult patients with glomerular diseases. It is the longest lasting and largest randomized controlled trial to examine MZR in Chinese patients. The results can help determine whether RNS should be considered as an additional indication for MZR treatment in China.

CLINICALTRIAL

ClinicalTrials.gov Register, NCT02257697. Registered 2014-10-01, https://clinicaltrials.gov/ct2/show/NCT02257697?term=MZR&rank=2.

Whole-exome sequencing of a multicenter cohort identifies genetic changes associated with clinical phenotypes in pediatric nephrotic syndrome

Understanding the association between the genetic and clinical phenotypes in children with nephrotic syndrome (NS) of different etiologies is critical for early clinical guidance. We employed whole-exome sequencing (WES) to detect monogenic causes of NS in a multicenter cohort of 637 patients. In this study, a genetic cause was identified in 30.0% of the idiopathic steroid-resistant nephrotic syndrome (SRNS) patients. Other than congenital nephrotic syndrome (CNS), there were no significant differences in the incidence of monogenic diseases based on the age at manifestation. Causative mutations were detected in 39.5% of patients with focal segmental glomerulosclerosis (FSGS) and 9.2% of those with minimal change disease (MCD). In terms of the patterns in patients with different types of steroid resistance, a single gene mutation was identified in 34.8% of patients with primary resistance, 2.9% with secondary resistance, and 71.4% of children with multidrug resistance. Among the various intensified immunosuppressive therapies, tacrolimus (TAC) showed the highest response rate, with 49.7% of idiopathic SRNS patients achieving complete remission. Idiopathic SRNS patients with monogenic disease showed a similar multidrug resistance pattern, and only 31.4% of patients with monogenic disease achieved a partial remission on TAC. During an average 4.1-year follow-up, 21.4% of idiopathic SRNS patients with monogenic disease progressed to end-stage renal disease (ESRD). Collectively, this study provides evidence that genetic testing is necessary for presumed steroid-resistant and idiopathic SRNS patients, especially those with primary and/or multidrug resistance.

Glomerulus-on-a-Chip: Current Insights and Future Potential Towards Recapitulating Selectively Permeable Filtration Systems

Glomerulopathy, characterized by a dysfunctional glomerular capillary wall, results in proteinuria, leading to end-stage renal failure and poor clinical outcomes, including renal death and increased overall mortality. Conventional glomerulopathy research, including drug discovery, has mostly relied on animal experiments because in-vitro glomerulus models, capable of evaluating functional selective permeability, was unavailable in conventional in-vitro cell culture systems. However, animal experiments have limitations, including time- and cost-consuming, multi-organ effects, unstable reproducibility, inter-species reliability, and the social situation in the EU and US, where animal experiments have been discouraged. Glomerulus-on-a-chip, a new in-vitro organ model, has recently been developed in the field of organ-on-a-chip research based on microfluidic device technology. In the glomerulus-on-a-chip, the podocytes and endothelial cells are co-cultured in a microfluidic device with physical stimuli that mimic the physiological environment to enhance cell function to construct a functional filtration barrier, which can be assessed by permeability assays using fluorescently labeled molecules including inulin and albumin. A combination of this glomerulus-on-a chip technology with the culture technology to induce podocytes and endothelial cells from the human pluripotent stem cells could provide an alternative organ model and solve the issue of animal experiments. Additionally, previous experiments have verified the difference in the leakage of albumin using differentiated podocytes derived from patients with Alport syndrome, such that it could be applied to intractable hereditary glomerulopathy models. In this review, we provide an overview of the features of the existing glomerulus-on-a-chip systems, focusing on how they can address selective permeability verification tests, and the challenges they involved. We finally discuss the future approaches that should be developed for solving those challenges and allow further improvement of glomerulus-on-a-chip technologies.

Long-Term Outcome of Secondary Steroid-Resistant Nephrotic Syndrome in Chinese Children

Introduction

Secondary steroid-resistant nephrotic syndrome (SRNS) refers to the condition when patients with initial steroid-sensitive nephrotic syndrome develop steroid resistance in subsequent relapses. Long-term outcomes of secondary SRNS in children are uncertain.

Methods

This was a single-center retrospective study of 56 children with secondary SRNS between 2006 and 2016. The survival curve was estimated using the Kaplan-Meier method. Independent risk factors for end-stage renal disease (ESRD) were determined using Cox proportional hazards model.

Results

The median time from nephrotic syndrome onset to secondary SRNS was 7.8 months. Biopsy results at diagnosis secondary SRNS showed that 64.3% of cases were minimal change disease (MCD). No remission was observed in seven (12.5%) patients within the first year. The mean follow-up time was 7.8 ± 3.2 years. Eight patients were clinically cured, one died before ESRD, 10 reached ESRD, and 75.0% (3 of 4) of patients recurred post-transplantation. The 10-year ESRD-free survival rate was 85.8%. No response to intensified immunosuppression (IIS) in the first year was the independent predictor for ESRD. Repeat biopsies were performed in 20 cases, revealing that the reclassification from MCD to mesangial hypercellularity and focal segmental glomerulosclerosis (FSGS) in two when secondary steroid resistance appeared, from MCD and mesangial hypercellularity to FSGS in seven who developed multidrug resistance, and from FSGS to MCD and mesangial hypercellularity in two with favorable outcomes.

Conclusions

The long-term outcome in children with secondary SRNS was heterogeneous, and no response to IIS in the first year was the independent predictor for ESRD. In patients with repeat biopsy, changes in histological appearance to FSGS were associated with multidrug resistance.

Association Between Macrophage Migration Inhibitory Factor -173 G>C Gene Polymorphism and Childhood Idiopathic Nephrotic Syndrome: A Meta-Analysis

Background: Studies have identified that MIF -173 G>C gene polymorphism is associated with idiopathic nephrotic syndrome (INS) susceptibility and steroid resistance, but the results remain inconclusive. Methods: We searched PubMed, Embase, and Web of Science for relevant studies published before 31 March 2021. Pooled data were reported as odds ratio (OR) with 95% confidence interval (CI). Noteworthiness of significant OR was estimated by the false positive report probability (FPRP) test. Trial sequential analysis (TSA) was used to control type I and type II errors. Results: We selected seven case-control studies that included 1,026 INS children (362 were steroid-resistant NS and 564 were steroid-sensitive NS) and 870 controls. The results showed that MIF -173 G>C polymorphism was significantly associated with INS susceptibility in allelic, heterozygous and dominant genetic models (C vs. G: OR = 1.325, 95% CI: 1.011-1.738; GC vs. GG: OR = 1.540, 95% CI: 1.249-1.899; CC + GC vs. GG: OR = 1.507, 95% CI: 1.231-1.845), and FPRP test and TSA indicated that the associations were true in heterozygous and dominant models. The pooled results also revealed that MIF -173 G>C polymorphism was significantly associated with steroid resistance in allelic, homozygous and recessive models (C vs. G: OR = 1.707, 95% CI: 1.013-2.876; CC vs. GG: OR = 4.789, 95% CI: 2.109-10.877; CC vs. GC + GG: OR = 4.188, 95% CI: 1.831-9.578), but FPRP test indicated that all these associations were not noteworthy. Furthermore, TSA revealed that the non-significant associations between MIF -173 G>C polymorphism and steroid resistance in heterozygous and dominant models were potential false negative. Conclusions: This meta-analysis could draw a firm conclusion that MIF -173 G>C polymorphism was significantly associated with increased INS risk in heterozygous and dominant genetic models. MIF -173 G>C polymorphism was not likely to affect steroid responsiveness, but more studies were needed to confirm.