Nephrotic syndrome: what's new, what's hot?

Effect of Nephropathy Prescription I on the Expression of Angptl3 and Podocyte-Associated Protein in Mice with Adriamycin-Induced Nephropathy

Objective

This study aimed to investigate the effects of Nephropathy Prescription I on the expression of angptl3, nephrin, and podocin, in addition to its protective effects on podocytes in mice with adriamycin-induced nephropathy.

Methods

BALB/c mice were randomly divided into the control (C), adriamycin (Model or M), adriamycin + Nephropathy Prescription I (M + Z), adriamycin + prednisone acetate (M + S), and adriamycin + Nephropathy Prescription I + prednisone acetate groups (M + Z + S). All mice except those in the C group in the experimental groups were treated with a single tail vein injection of adriamycin. The urine albumin-creatinine ratio was measured before model establishment and on the 7th day, 14th day, 21st day, and 28th day of doxorubicin injection. All the mice were sacrificed on the 29th day. Blood samples were collected to observe biochemical indicators in the serum. The morphological structure and podocyte ultrastructure in the kidney were observed using light and electron microscopy, respectively. The expression of angptl3, nephrin, and podocin at the mRNA and protein levels was detected by real-time PCR and western blotting, respectively.

Results

Following modeling with adriamycin, albuminuria was observed in urine samples in the first week, and the urinary protein/creatinine ratio increased maximally in the fourth week in the M group (P < 0.05). In contrast, the urinary protein/creatinine ratio significantly decreased (P < 0.05) in the third week in the (M + Z) group compared to that in the M group. Similarly, this ratio decreased in the (M + S) and (M + Z + S) groups compared to that in the M group throughout the experiment. Compared with the C group, serum albumin content and the expression of nephrin and podocin decreased (P < 0.05), whereas blood lipid level and the expression of angptl3 increased (P < 0.05) in the M group. Glomerular foot process fusion was observed in this group using electron microscopy. In all the intervention groups, serum albumin content and the expression of nephrin and podocin increased (P < 0.05), whereas blood lipid level and the expression of angptl3 decreased (P < 0.05), with alleviated glomerular foot process injury observed particularly in the (M + Z + S) group.

Conclusion

The Nephropathy Prescription I can alleviate albuminuria, increase serum albumin levels, lower blood lipid levels, and reduce the fusion of foot processes of podocytes in mice with adriamycin-induced nephropathy. The protective effects of the Nephropathy Prescription I may function by reducing Angptl3 expression and increasing nephrin and podocin expression.

Efficacy of rituximab therapy in children with nephrotic syndrome: a 10-year experience from an Iranian pediatric hospital

Background

There are controversy results in the optimal management of children with steroid-dependent and steroid-resistant nephrotic syndrome (SDNS, SRNS). This study aimed to determine the efficacy and safety of rituximab (RTX) in these pediatric patients.

Methods

Medical records of 1–18-year-old Iranian children with SDNS (n = 26) and SRNS (n = 22) with a follow-up for at least 24 months were included from 2009 to 2019. The short- and long-term responses to RTX were respectively evaluated to determine the random protein-to-creatinine ratio after 6 and 24 months and classified as complete (CR) and partial (PR) remission or no response.

Results

Male patients (n = 26) were slightly predominate. The median age of patients at the time of RTX therapy was 8.6 ± 4.01 years. At the end of the 6-month follow-up, CR and PR occurred in 23 (47.9%) and 12 (25%) patients, respectively. Of 23 patients with CR, 18 (69.2%) and 5(22.7%) had SDNS and SRNS, respectively (p < 0.005). However, only 18 (37.5%) of patients after 24 months had been in CR. No significant difference in the CR rate was found between the two groups. RTX was more effective when administered during the proteinuria-free period (p = 0.001).

Conclusion

In the short term, RTX significantly was efficient in inducing complete or PR in SDNS and SRNS patients. However, the favorable response rate in a long-term follow-up was insignificantly lower between the two groups.

Diversity and molecular network patterns of symptom phenotypes

Symptom phenotypes have continuously been an important clinical entity for clinical diagnosis and management. However, non-specificity of symptom phenotypes for clinical diagnosis is one of the major challenges that need be addressed to advance symptom science and precision health. Network medicine has delivered a successful approach for understanding the underlying mechanisms of complex disease phenotypes, which will also be a useful tool for symptom science. Here, we extracted symptom co-occurrences from clinical textbooks to construct phenotype network of symptoms with clinical co-occurrence and incorporated high-quality symptom-gene associations and protein-protein interactions to explore the molecular network patterns of symptom phenotypes. Furthermore, we adopted established network diversity measure in network medicine to quantify both the phenotypic diversity (i.e., non-specificity) and molecular diversity of symptom phenotypes. The results showed that the clinical diversity of symptom phenotypes could partially be explained by their underlying molecular network diversity (PCC = 0.49, P-value = 2.14E-08). For example, non-specific symptoms, such as chill, vomiting, and amnesia, have both high phenotypic and molecular network diversities. Moreover, we further validated and confirmed the approach of symptom clusters to reduce the non-specificity of symptom phenotypes. Network diversity proposes a useful approach to evaluate the non-specificity of symptom phenotypes and would help elucidate the underlying molecular network mechanisms of symptom phenotypes and thus promotes the advance of symptom science for precision health.

Reliability of generic quality-of-life instruments in assessing health-related quality of life among children and adolescents with idiopathic nephrotic syndrome: a systematic review

INTRODUCTION

Most of the studies reporting the negative impact of idiopathic nephrotic syndrome on health-related quality of life in children and adolescents were conducted with generic quality-of-life instruments rather than disease-specific instruments. The consistency of these studies' findings using these generic instruments is not well established.

AIM

This systematic review aims to determine the reliability of current generic quality-of-life instruments in assessing health-related quality of life among children and adolescents with idiopathic nephrotic syndrome.

METHODS

We searched the PubMed, MEDLINE, EMBASE, and Google Scholar databases for articles published between 2000 and 2020, using appropriate descriptors. We included primary studies that met the eligibility criteria, independently screened their titles and abstracts, and removed all duplicates during the study-selection process. We resolved disagreements until a consensus was reached on study selection. We independently retrieved relevant data, including the generic quality-of-life instruments and the subjects' and controls' aggregate health-related quality of life scores, using a preconceived data-extraction form.

RESULTS

Ten original articles were selected for qualitative and quantitative analyses. Some of the studies reported the following significant findings. The mean health-related quality of life scores for children with prevalent and incident nephrotic syndrome were 68.6 (range, 52.6-84.6) and 73.7 (range, 55.9-91.5), respectively. Children with idiopathic nephrotic syndrome and their controls with other chronic diseases had median scores of 65 (interquartile range, 59-68.75) and 62.2 (interquartile range, 58.05-65.78). Patients on oral immunosuppressive drug and intravenous rituximab reportedly had median scores of 76.2 and 72.6 and mean scores of 71.4 (range, 55.4-87.4) and 61.6 (range, 42.1-81.1) respectively for quality-of-life assessment on the 'school functioning domain.'

CONCLUSIONS

The health-related quality of life scores in patients with idiopathic nephrotic syndrome are consistently low. Lower scores occur in prolonged disease duration and severe clinical phenotypes, whereas the scores are higher than the scores obtained in other chronic diseases. These consistent findings underscore the reliability of the current generic instruments in assessing health-related quality of life in patients with idiopathic nephrotic syndrome.

Prevalence rates of histopathologic subtypes associated with steroid resistance in childhood nephrotic syndrome in Sub-Saharan Africa: a systematic review

Introduction

The prevalence rates of the common histopathologic subtypes of childhood nephrotic syndrome associated with steroid resistance appear to be changing globally. In Sub Saharan Africa (SSA), the trend is similar over the past few decades.

Aim

This systematic review aims to determine the current prevalence rates of the histopathologic subtypes associated with childhood steroid-resistant nephrotic syndrome (SRNS) in SSA.

Methods

A search of the PubMed, Google and African Journals Online databases was conducted from January to December 2018 using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow-chart to identify relevant articles which met the aim of the systematic review. A qualitative synthesis and descriptive analysis of the extracted data were then conducted. The mean values for the prevalence rates of the reported histopathologic subtypes were calculated. A meta-analysis was not done due to few numbers of studies reviewed. The review is registered with PROSPERO, number CRD42018111916.

Results

In the West African sub-region, the currently reported histopathologic subtypes associated with childhood nephrotic syndrome are focal segmental glomerulosclerosis (FSGS), minimal-change nephropathy (MCN), membrano-proliferative glomerulonephritis (MPGN), membranous nephropathy (MN) and mesangial proliferative glomerulonephritis (MesPGN). The picture is the same in South Africa. More importantly, the predominant histopathologic lesions associated with steroid resistance are FSGS (West Africa) and MCN/FSGS (South Africa), with mean prevalence rates of 57.2% and 36.1% respectively.

Conclusion

The prevalence of FSGS is currently high in childhood nephrotic syndrome in SSA. This histopathologic subtype remains the commonest lesion associated with SRNS in this part of the globe.

Low-dose rituximab is no less effective for nephrotic syndrome measured by 12-month outcome

OBJECTIVE

Rituximab is an effective treatment for children with steroid dependent or frequently relapsing nephrotic syndrome. The optimum dosing schedule for rituximab has not been established. We hypothesized that a single low dose of 375 mg/m² would have comparable outcomes to higher doses in reducing the frequency of relapse and time to B cell reconstitution.

METHODS

We conducted a multicenter retrospective observational cohort study of children with steroid-sensitive frequently relapsing nephrotic syndrome. Data were extracted from clinical records including the dates of diagnosis, treatment, relapses, the use of concomitant immunosuppression, and lymphocyte subset profiling. Patients treated earlier received variable doses of rituximab, although typically two doses of 750 mg/m². Later, patients received the current regimen of a single dose of 375 mg/m². The primary outcome was an absence of clinically confirmed relapse 12 months following rituximab administration. Secondary outcomes were median time to relapse, probability of being relapse-free at 6 and 24 months and time to reconstitution of CD19⁺ B cells.

RESULTS

Sixty patients received 143 courses of rituximab. Seven different dosing regimen strategies were used, ranging between 375 and 750 mg/m² per dose, with administration of 1-4 doses. There was no significant difference in event-free survival at 12 months between dosing strategies. The median time to reconstitution of B cells was not significantly different between groups.

CONCLUSIONS

Use of a single low-dose regimen of rituximab in the management of frequently relapsing nephrotic syndrome does not affect the probability of relapse at 12 months or time to B cell reconstitution compared to a conventional higher dose.

Recent Advances in Treatments of Primary Focal Segmental Glomerulosclerosis in Children

Focal segmental glomerulosclerosis (FSGS) is a nephrotic syndrome. Up to around 80% of cases of primary FSGS are resistant to steroid treatment. A large proportion of patients with steroid-resistant FSGS progress to end-stage renal disease. The purpose of treatment is to obtain a complete remission of proteinuria, a necessary step that precedes improved renal survival and reduces the risk of progression to chronic kidney disease. When this is not possible, the secondary goal is a partial remission of proteinuria. Reduction or remission of proteinuria is the most important factor predictive of renal survival. We will review the current updated strategies for treatment of primary FSGS in children, including traditional therapies consisting of corticosteroids and calcineurin inhibitors and novel therapies such as rituximab, abatacept, adalimumab, and fresolimumab.