Salvianolic acid A attenuates steroid resistant nephrotic syndrome through suPAR/uPAR-αvβ3 signaling Inhibition

ETHNOPHARMACOLOGICAL RELEVANCE

Salvianolic acid A (SAA) is extracted from traditional Chinese medicine Salvia miltiorrhiza and is the main water-soluble and the biologically active ingredient. SAA possesses a variety of pharmacological activities and has an excellent protective effect on kidney disease, especially steroid resistant nephrotic syndrome (SRNS), and has advantages in improving the efficacy of glucocorticoids, but its mechanism needs to be further explored.

PURPOSE

The study was designed to explore the effect of suPAR and uPAR in SRNS patients and evaluate the potential effect of SAA in improving podocyte steroid resistance and explore its mechanism.

METHODS AND MATERIALS

The ELISA kits were used to detect the levels of suPAR in the blood and urine of subjects. The levels of uPAR, GRα, and GRβ expression in renal tissues of SRNS patients was detected by immunohistochemistry and analyzed using the Pearson method. In vitro studies, steroid resistance model was induced by the TNF-α and IFN-γ. The protein and mRNA expression of Nephrin, GR, GRα and GRβ were analyzed using western blot and qRT-PCR. The activity of GR-DNA binding was detected by using TransAM™ GR kits. Adriamycin further induced steroid resistance podocyte. Flow cytometry was used to detect the effect of SAA on podocyte apoptosis. ELISA assay was used to detect the suPAR expression in the podocyte supernatant. Western blot and qRT-PCR were used to detect the protein and mRNA expression of uPAR and Nephrin in podocytes.

RESULTS

The serum and urine levels of suPAR were conspicuously higher in SRNS patients than healthy volunteers and SSNS patients, and the expression of uPAR in renal tissue of SRNS patients is negatively correlated with GRα, but positively correlated with GRβ. The combination of TNF-α and IFN-γ could conspicuously increase the GRβ expression and reduce GRα/GRβ, and induce steroid resistance in podocytes. Moreover, we found that SAA could reduce the apoptosis of podocytes and suppress the expression of suPAR/uPAR, and increase the expression of Nephrin.

CONCLUSION

The level of suPAR and uPAR expression may have important value in predicting glucocorticoids resistance in patients with idiopathic nephrotic syndrome (INS). The combination of TNF-α and IFN-γ induce podocytes can establish steroid resistance model in vitro. SAA could improve glucocorticoids resistance of podocyte which can be attributed in part to regulate the suPAR/uPAR-αvβ3 signaling pathway.

A Novel Model for Nephrotic Syndrome Reveals Associated Dysbiosis of the Gut Microbiome and Extramedullary Hematopoiesis

Glomerular kidney disease causing nephrotic syndrome is a complex systemic disorder and is associated with significant morbidity in affected patient populations. Despite its clinical relevance, well-established models are largely missing to further elucidate the implications of uncontrolled urinary protein loss. To overcome this limitation, we generated a novel, inducible, podocyte-specific transgenic mouse model (Epb41l5^fl/fl*Nphs1-rtTA-3G*tetOCre), developing nephrotic syndrome in adult mice. Animals were comprehensively characterized, including microbiome analysis and multiplexed immunofluorescence imaging. Induced knockout mice developed a phenotype consistent with focal segmental glomerular sclerosis (FSGS). Although these mice showed hallmark features of severe nephrotic syndrome (including proteinuria, hypoalbuminemia and dyslipidemia), they did not exhibit overt chronic kidney disease (CKD) phenotypes. Analysis of the gut microbiome demonstrated distinct dysbiosis and highly significant enrichment of the Alistipes genus. Moreover, Epb41l5-deficient mice developed marked organ pathologies, including extramedullary hematopoiesis of the spleen. Multiplex immunofluorescence imaging demonstrated red pulp macrophage proliferation and mTOR activation as driving factors of hematopoietic niche expansion. Thus, this novel mouse model for adult-onset nephrotic syndrome reveals the significant impact of proteinuria on extra-renal manifestations, demonstrating the versatility of this model for nephrotic syndrome-related research.

Vascular Endothelial Growth Factor (VEGF) and Neopterin Levels in Children with Steroid-sensitive and Steroid-resistant Nephrotic Syndrome

BACKGROUND

The most common glomerular disease in children is nephrotic syndrome. Steroid-resistant nephrotic syndrome tends to have a worse disease course, which bears a significant risk of chronic kidney disease in children.

OBJECTIVE

To compare VEGF and neopterin levels between children with steroid-sensitive nephrotic syndrome (SSNS), steroid-resistant nephrotic syndrome (SRNS), and also healthy (control) children.

METHODS

This cross-sectional study was conducted at H. Adam Malik General Hospital, Indonesia from January to December 2018. There were 160 children aged 1 to 8 years with confirmed nephrotic syndrome and without end-stage renal disease and systemic diseases, divided into SSNS, SRNS, and control groups. Data regarding age, gender, urine albumin creatinine ratio (UACR), serum albumin, total cholesterol, urea, creatinine, VEGF, and neopterin levels were collected. A p-value of less than 0.05 is considered statistically significant.

RESULTS

There were no differences between groups in gender (p = 0.269) and age (p = 0.375), but there was significant difference of UACR, albumin level, total cholesterol level, and VEGF level between groups, (all p< 0.001). There was a moderate positive correlation between VEGF level and UACR (r(158) = 0.439, p< 0.001) and a moderate negative correlation between neopterin level and albumin level (r(158)= -0.312, p = 0.005).

CONCLUSION

There were no differences in serum VEGF and neopterin levels between steroid-sensitive and steroid-resistant nephrotic syndrome groups. Serum VEGF level was positively correlated with UACR while serum neopterin level was negatively correlated with serum albumin level.

Use of angiotensin II receptor blocker during pregnancy: A case report

BACKGROUND

Drugs that affect the renin-angiotensin system, such as angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors are not typically recommended for pregnant women because of their potential fetal toxicity.

CASE STUDY

A 32-year-old pregnant woman with nephrotic syndrome lasting more than 5 years became pregnant for the first time. She had been taking losartan tablets before and during pregnancy. Ultrasound at 24+2 weeks of pregnancy showed oligohydramnios, and the maximum vertical depth of amniotic fluid volume was 1.4 cm. Follow-up ultrasound examinations every 2 weeks showed persistent oligohydramnios [amniotic fluid volume: 1.1-3.4 cm, amniotic fluid index 1.9-6.9 cm]. B-ultrasound at 30+2 weeks showed slightly enhanced fetal renal cortex echo. The patient was treated at 32+2 weeks of pregnancy at our hospital.

DIAGNOSES

Nephrotic syndrome and oligohydramnios.

INTERVENTIONS

Losartan was discontinued and replaced by nifedipine controlled-release tablets to lower blood pressure. The amount of amniotic fluid gradually increased to normal levels within 8 days. The patient was discharged at 33+2 weeks of pregnancy for follow-up. At 34+4 weeks, blood pressure had increased to 177/113 mm Hg and the patient was re-hospitalized with nephrotic syndrome complicated by preeclampsia. Due to progression of severe preeclampsia, elective cesarean section was performed at 35+3 weeks. After delivery, losartan and nifedipine were prescribed to continue lowering blood pressure. The patient was discharged 4 days after surgery.

OUTCOMES

Losartan use was terminated at 32+2 weeks of pregnancy. Amniotic fluid returned to normal after 8 days and the baby was delivered after 22 days. At last follow-up, the infant was 24 months old and healthy.

CONCLUSION

Although ARBs are effective for treating hypertension, they should be replaced by other classes of anti-hypertensive drugs in pregnant women. Pregnant women who elect to continue using ARBs should be informed about risks, they should be carefully monitored during pregnancy, and their pregnancy should be allowed to proceed as long as clinically feasible in order to optimize maternal and infant outcomes.

Pediatric idiopathic steroid-sensitive nephrotic syndrome: diagnosis and therapy -short version of the updated German best practice guideline (S2e) - AWMF register no. 166-001, 6/2020

Idiopathic nephrotic syndrome is the most frequent glomerular disease in children in most parts of the world. Children with steroid-sensitive nephrotic syndrome (SSNS) generally have a good prognosis regarding the maintenance of normal kidney function even in the case of frequent relapses. The course of SSNS is often complicated by a high rate of relapses and the associated side effects of repeated glucocorticoid (steroid) therapy. The following recommendations for the treatment of SSNS are based on the comprehensive consideration of published evidence by a working group of the German Society for Pediatric Nephrology (GPN) based on the systematic Cochrane reviews on SSNS and the guidelines of the KDIGO working group (Kidney Disease - Improving Global Outcomes).

A cross-sectional nationwide survey of congenital and infantile nephrotic syndrome in Japan

BACKGROUND

Congenital nephrotic syndrome (CNS) and infantile nephrotic syndrome (INS) cause substantial morbidity and mortality. In Japan, there is a lack of knowledge regarding the characteristics of CNS and INS. This study aimed to clarify the characteristics of CNS and INS in Japan.

METHODS

This cross-sectional nationwide survey obtained data from 44 institutions in Japan managing 92 patients with CNS or INS, by means of two survey questionnaires sent by postal mail. Patients aged < 16 years by 1 April 2015, with a diagnosis of CNS or INS, were included in this study. The primary outcome was end-stage kidney disease.

RESULTS

A total of 83 patients with CNS or INS were analyzed. The most frequent disease type was non-Finnish (60.2%); 33 patients (39.8%) had Finnish type. Among those with non-Finnish-type disease, 26 had no syndrome and 24 had a syndrome, of which the most frequent was Denys-Drash syndrome (70.8%). Patients with non-Finnish-type disease with syndrome showed the earliest progression to end-stage kidney disease compared with the other two groups, whereas patients with non-Finnish-type disease without syndrome progressed more slowly compared with the other two groups. In the Finnish-type group, the disease was diagnosed the earliest; a large placenta was reported more frequently; genetic testing was more frequently performed (93.8%); mental retardation was the most frequent extra-renal symptom (21.2%); and thrombosis and infection were more frequent compared with the other groups. Patients with non-Finnish-type disease with syndrome had a higher frequency of positive extra-renal symptoms (79.2%), the most common being urogenital symptoms (54.2%). Treatment with steroids and immunosuppressants was more frequent among patients with non-Finnish-type disease without syndrome. Two patients with non-Finnish-type disease without syndrome achieved complete remission. In all groups, unilateral nephrectomy was performed more often than bilateral nephrectomy and peritoneal dialysis was the most common renal replacement therapy.

CONCLUSIONS

The present epidemiological survey sheds light on the characteristics of children with CNS and INS in Japan. A high proportion of patients underwent genetic examination, and patient management was in accord with current treatment recommendations and practices.

TRIAL REGISTRATION

Not applicable.

A single-center analysis of primary nephrotic syndrome with acute pancreatitis in children

Primary nephrotic syndrome (PNS) is one of the most common primary glomerular diseases in children. Patients complicated nephrotic syndrome with pancreatic lesions are rarely reported, and the clinical manifestations in children are atypical. This study has observed the incidence, clinical types, and prognosis of acute pancreatitis (AP) in children with primary nephrotic syndrome, and analyzed its related factors, early diagnosis, and treatment.Seven children with PNS and AP in Shanghai Children's Hospital from January 2015 to December 2017 were reviewed. The clinical data including age, height, weight, body mass index (BMI), diet, biliary tract disease, PNS durations, drugs, proteinuria, creatinine, glucose, glycated hemoglobin, amylase and lipase, albumin, cholesterol, triglyceride, ultrasound, computerized tomography (CT), renal pathology and estimated glomerular filtration rate (eGFR) were retrospectively analyzed. All patients were followed for >2 years.Ten in 589 patients with PNS were detected pancreatic lesions by abdominal ultrasound. Seven were diagnosed as AP, which the incidence was 1.2%. Only 1 of 7 patients had elevated serum amylase. Lesions of pancreas were found by ultrasound and/or enhanced CT. Four of 7 patients had been treated with tacrolimus. All patients with AP were improved after octreotide acetate injection and supportive treatment. Only 1 patient suffered recurrent AP during the relapse of PNS 10 months later.AP in children with PNS is not common, and the clinical manifestations are not typical. Abdominal ultrasound and enhanced CT are of high value in diagnosis. The adverse effects of tacrolimus should be concerned. Early diagnosis and timely treatment can be helpful for a prognosis.

Treatment of nephrotic syndrome: going beyond immunosuppressive therapy

It is indisputable that immunosuppressive therapy and pathological diagnosis of renal biopsy have greatly improved the prognosis of childhood nephrotic syndrome. Unfortunately, there is no "one-size-fits-all" approach for precise patient stratification and treatment when facing the huge challenges posed by steroid-resistant nephrotic syndrome (SRNS). But genomic medicine has brought a glimmer of light, and the cognition of SRNS has entered a new stage. Based on this, identification of single genetic variants of SRNS has recognized the key role of podocyte injury in its pathogenesis. Targeted treatment of podocyte injury is paramount, and immunosuppressant with podocyte-targeted therapy seems to be more suitable as the first choice for SRNS, that is, we need to pay attention to their additional non-immunosuppressive effects. In the same way, other effect factors of nephrotic syndrome and the related causes of immunosuppressive therapy resistance require us to select reasonable and targeted non-immunosuppressive therapies, instead of only blindly using steroids and immunosuppressants, which may be ineffective and bring significant side effects. This article provides a summary of the clinical value of identification of genetic variants in podocytes and non-immunosuppressive therapy for nephrotic syndrome in children.

Beyond the adrenals: Organ manifestations in inherited primary adrenal insufficiency in children

Primary adrenal insufficiency (PAI) in children is mostly due to genetic defects. The understanding of the molecular genetics of the causes of adrenal insufficiency in the pediatric population has made significant progress during the last years. It has been shown that inherited PAI can lead to certain clinical manifestations and health problems in children beyond the adrenals. Organ dysfunctions associated with different forms of PAI in children include a wide range of organs such as gonads, brain, heart, bone, growth, bone marrow, kidney, skin, parathyroid, and thyroid. Diagnosing the correct genetic cause of PAI in children is therefore crucial to adequately control long-term treatment and follow-up in such patients.

Association of low birth weight and prematurity with clinical outcomes of childhood nephrotic syndrome: a prospective cohort study

BACKGROUND

Low birth weight (LBW)/prematurity have been proposed as risk factors for the development of kidney disease in adulthood. Whether there is an association between LBW/prematurity and poor renal outcomes in childhood onset nephrotic syndrome remains unknown.

METHODS

Children with nephrotic syndrome diagnosed between 1 and 18 years of age were followed prospectively from 1996 to 2016 at The Hospital for Sick Children (N = 377). LBW/prematurity was defined as birth weight < 2500 g or gestational age < 36 weeks. Normal birth weight (NBW) was defined as birth weight ≥ 2500 g. Measures evaluating clinical course of nephrotic syndrome include initial steroid-resistant nephrotic syndrome (SRNS), time to first relapse, and frequently relapsing nephrotic syndrome. Kaplan-Meier survival analysis, logistic regression, and Cox proportional hazards regression were used to determine the association of LBW/prematurity with clinical outcomes.

RESULTS

Median birth weights in LBW/premature (n = 46) and NBW (n = 331) children were 2098 g (interquartile range [IQR] 1700-2325 g) and 3317 g (IQR 2977-3685 g), respectively. Odds of having SRNS were 3.78 (95% confidence interval [CI] 1.28-11.21) times higher among LBW/premature children than NBW children. An 8% decrease in odds of developing SRNS was observed for every 100 g increase in birth weight (adjusted odds ratio [OR] 0.92; 95% CI 0.86-0.98). Median time to first relapse did not differ (hazard ratio [HR] 0.89; 95% CI 0.53-1.16).

CONCLUSIONS

LBW/premature children were more likely to develop SRNS but did not have a difference in time to first relapse with NBW children. Understanding the impact and mechanism of birth weight and steroid-resistant disease needs further study.

Relationships between the clinical phenotypes and genetic variants associated with the immunological mechanism in childhood idiopathic nephrotic syndrome: protocol for a prospective observational single-centre cohort study

INTRODUCTION

Idiopathic nephrotic syndrome (INS) is the most common glomerulopathy that results in childhood chronic kidney disease in China, but the relationships between different clinical phenotypes and immunological genetic variants observed in patients with INS are ambiguous and have not been well studied. A cohort study combined with whole exome sequencing might further identify the effects of immunological genetic variants on clinical phenotypes and treatment outcomes.

METHODS AND ANALYSIS

We describe a 3 year prospective observational single-centre cohort study to be conducted in the Children's Hospital of Chongqing Medical University in China. This study will recruit and investigate 336 patients with childhood-onset INS presenting with different clinical phenotypes. Whole exome sequencing will be conducted when patients progress to a confirmed clinical phenotype during follow-up. Relevant clinical and epidemiological data, as well as conventional specimens, will be collected at study entry and 1 month, 3 months, 6 months, 1 year, 2 years and 3 years after disease onset. After this cohort is generated, the immunological genetic variants of steroid-sensitive nephrotic syndrome without frequent relapse, steroid-resistant nephrotic syndrome and steroid-dependent/frequent relapse nephrotic syndrome will be evaluated.

ETHICS AND DISSEMINATION

The study protocol is approved by Ethics Committee of Children's Hospital of Chongqing Medical University (reference number 2018-140). The results will be disseminated through peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

ChiCTR1800019795.

Pathogenesis and Management of Acute Kidney Injury in Patients with Nephrotic Syndrome Due to Primary Glomerulopathies

Acute kidney injury in the context of nephrotic syndrome is a serious and alarming clinical problem. Largely, acute kidney injury is a relatively frequent complication among patients with comorbidities while it has been independently associated with an increased risk of adverse outcomes, including death and chronic kidney disease. Nephrotic syndrome, without hematuria or with minimal hematuria, includes a list of certain glomerulopathies; minimal change disease, focal segmental glomerulosclerosis and membranous nephropathy. In the light of primary nephrotic syndrome, pathophysiology of acute kidney injury is differentiated by the nature of the primary disease and the severity of the nephrotic state. This review aims to explore the clinical circumstances and pathogenetic mechanisms of acute kidney injury in patients with nephrotic syndrome due to primary glomerulopathies, focusing on newer perceptions regarding the pathogenesis and management of this complicated condition, for the prompt recognition and timely initiation of appropriate treatment in order to restore renal function to its baseline level. Prompt recognition of the precise cause of acute kidney injury is crucial for renal recovery. Clinical characteristics, laboratory and serological findings along with histopathological findings, if required, will reveal the implicated pathway leading to individualized approach and management.

Association of Urinary Plasminogen-Plasmin with Edema and Epithelial Sodium Channel Activation in Patients with Nephrotic Syndrome

BACKGROUND

Previous animal experiments and small human studies suggest that urinary plasmin can activate the epithelial sodium channel (ENaC) and contribute to sodium retention in nephrotic syndrome (NS), but this however is not well studied in clinical settings, and its relevance to edema formation is not well characterized in humans. We have investigated the association between urinary plasmin and clinical phenotypes in a large group of patients with NS from multiple etiologies, aiming to assess the role of urinary plasmin in sodium handling and edema formation.

METHODS

Two hundred and three NS patients with urine and blood samples were divided into mild and severe symptom groups based on their edema severity. Twenty six of them had serial samples collected during the course of immunosuppressive therapy. The plasminogen-plasmin level and other key parameters were assayed, and their association with clinical manifestations were analyzed.

RESULTS

One hundred and one of the 203 patients had renal biopsies performed, the results of which had included all the common types of primary NS and various types of secondary NS. Quantitative comparison and multivariate logistic regression analysis identified urinary plasminogen-plasmin to creatinine ratio (uPLG-PL/C), serum albumin, D-Dimer, and cardiac dysfunction history, but not albuminuria or 24-h urine protein, as independent risk factors for edema (p < 0.01). In patients who were treated and had serial samples, a decrease in uPLG-PL/C was identified as an independent influencing factor of edema remission (p < 0.01). Finally, the urinary fractional excretion of sodium (FENa) in patients was inversely correlated with the fractional excretion of potassium (FEK; p< 0.001), and FEK/FENa ratio was positively correlated with uPLG-PL/C (p < 0.001), suggesting a close association between uPLG-PL and ENaC activation.

CONCLUSIONS

Our study identifies uPLG-PL abundance as an independent influencing factor of edema in adult NS patients, and supports the conclusion that plasmin-dependent ENaC activation is an important pathophysiological mechanism of sodium retention and edema formation in humans with NS.

A Novel Hybrid Cytokine IL233 Mediates regeneration following Doxorubicin-Induced Nephrotoxic Injury

Kidney injury, whether due to ischemic insults or chemotherapeutic agents, is exacerbated by inflammation, whereas Tregs are protective. We recently showed that IL-2 and IL-33, especially as a hybrid cytokine (IL233 - bearing IL-2 and IL-33 activities in one molecule), potentiated Tregs and group 2 innate lymphoid cells (ILC2) to prevent renal injury. Recent studies have indicated a reparative function for Tregs and ILC2. Here, using doxorubicin-induced nephrotoxic renal injury model, we investigated whether IL233 administration either before, late or very late after renal injury can restore kidney structure and function. We found that IL233 treatment even 2-weeks post-doxorubicin completely restored kidney function accompanied with an increase Treg and ILC2 in lymphoid and renal compartments, augmented anti-inflammatory cytokines and attenuated proinflammatory cytokine levels. IL233 treated mice had reduced inflammation, kidney injury (Score values - saline: 3.34 ± 0.334; IL233 pre: 0.42 ± 0.162; IL233 24 hrs: 1.34 ± 0.43; IL233 1 week: 1.2 ± 0.41; IL233 2 week: 0.47 ± 0.37; IL233 24 hrs + PC61: 3.5 ± 0.74) and fibrosis in all treatment regimen as compared to saline controls. Importantly, mice treated with IL233 displayed a reparative program in the kidneys, as evidenced by increased expression of genes for renal progenitor-cells and nephron segments. Our findings present the first evidence of an immunoregulatory cytokine, IL233, which could be a potent therapeutic strategy that augments Treg and ILC2 to not only inhibit renal injury, but also promote regeneration.

Brachial Artery Flow-mediated Dilatation and Carotid Intima-Media Thickness in Children With Idiopathic Nephrotic Syndrome

INTRODUCTION

Disturbances of lipid metabolism has been reported in nephrotic syndrome (NS) and may predispose to atherosclerosis. This study aimed to investigate the correlation between cardiovascular risk factors and carotid intima-media thickness (CIMT) and brachial artery flow-mediated dilatation in patients with idiopathic NS.

MATERIALS AND METHODS

This case-control study included 31 patients with NS and 31 healthy individuals as the control group. All patients were subjected to full clinical examination; laboratory investigations in the form of lipid profile, kidney function tests, serum protein, serum albumin, C-reactive protein, and ferritin; carotid ultrasonography, and brachial artery flow-mediated dilatation.

RESULTS

Serum cholesterol, low-density lipoprotein cholesterol, and triglyceride levels was significantly higher in the case group than the control group. High-density lipoprotein cholesterol and albumin levels were significantly lower in the case group. The absolute change in brachial artery diameter was significantly lower in the case group than that of the control group. Proportionate change in brachial artery diameter was significantly lower in the case group than that of the control group. Common carotid artery CIMT in the case group was significantly higher than that of the controls. Lastly, there were significant increases in weight and body mass index in the relapse group than the remission group.

CONCLUSIONS

Patients with NS are more prone to atherosclerosis and vascular changes; CIMT was thicker in nephrotic children compared to the controls. The significantly abnormal values of flow-mediated dilatation in children with NS suggests an ongoing process of endothelial dysfunction.

Single-nephron proteomes connect morphology and function in proteinuric kidney disease

In diseases of many parenchymatous organs, heterogeneous deterioration of individual functional units determines the clinical prognosis. However, the molecular characterization at the level of such individual subunits remains a technological challenge that needs to be addressed in order to better understand pathological mechanisms. Proteinuric glomerular kidney diseases are frequent and assorted diseases affecting a fraction of glomeruli and their draining tubules to variable extents, and for which no specific treatment exists. Here, we developed and applied a mass spectrometry-based methodology to investigate heterogeneity of proteomes from individually isolated nephron segments from mice with proteinuric kidney disease. In single glomeruli from two different mouse models of sclerotic glomerular disease, we identified a coherent protein expression module consisting of extracellular matrix protein deposition (reflecting glomerular sclerosis), glomerular albumin (reflecting proteinuria) and LAMP1, a lysosomal protein. This module was associated with a loss of podocyte marker proteins while genetic ablation of LAMP1-correlated lysosomal proteases could ameliorate glomerular damage in vivo. Furthermore, proteomic analyses of individual glomeruli from patients with genetic sclerotic and non-sclerotic proteinuric diseases revealed increased abundance of lysosomal proteins, in combination with a decreased abundance of mutated gene products. Thus, altered protein homeostasis (proteostasis) is a conserved key mechanism in proteinuric kidney diseases. Moreover, our technology can capture intra-individual variability in diseases of the kidney and other tissues at a sub-biopsy scale.

Cardiovascular outcomes of Nephrotic syndrome in childhood (CVONS) study: a protocol for prospective cohort study

BACKGROUND

Nephrotic syndrome (NS) is characterized by dyslipidemia which is a well-known risk factor for atherogenesis. Atherosclerosis in childhood is mostly subclinical and endothelial dysfunction is known to precede this. Evidence for screening for endothelial dysfunction and cardiovascular risk factors and early identification of premature onset of atherosclerosis in childhood NS remains tenuous in the absence of well-designed prospective studies addressing cardiovascular comorbidity in NS. The objective of our study is to examine endothelial dysfunction and short-term cardiovascular outcomes in a carefully phenotyped cohort of patients with Nephrotic syndrome as compared to healthy controls.

METHODS

In a multi-centric prospective cohort study, 70 Steroid Resistant NS (SRNS), 70 Steroid Sensitive (SSNS) patients along with 70 Healthy Controls are being recruited. After a baseline assessment of functional and structural status of heart (2D Echocardiography), arteries (Carotid Doppler and Intima Media Thickness measurements) and microcirculation [a combination of 2D Echocardiography, Laser Doppler Flowmetry (LDF) and Brachial Artery Flow mediated dilation (FMD) and Nail Fold Capillaroscopy (NFC)], the patients are being investigated for endothelial dysfunction. Venous blood sample (15 ml) is being collected for routine investigations and assay of biochemical endothelial markers through Flow Cytometry. The patients will be followed up at 12 months and 24 months after the recruitment to look for any change from baseline period.

DISCUSSION

This study will able to provide a better understanding of the epidemiology of endothelial dysfunction and associated subclinical cardiovascular co-morbidity in childhood NS. Findings on characterization of prevalence of endothelial dysfunction and subclinical markers may be used to design future randomized controlled trials for evaluating the efficacy of preventive and therapeutic interventions in reducing the incidence of cardiovascular disease.

Skeletal impairment in Pierson syndrome: Is there a role for lamininβ2 in bone physiology?

INTRODUCTION

Pierson syndrome is caused by a mutation of LAMB2, encoding for laminin β2. Clinical phenotype is variable but usually associates congenital nephrotic syndrome (CNS) and ocular abnormalities. Neuromuscular impairment has also been described.

METHODS

We report on a 15-year old girl, suffering from Pierson Syndrome, who developed severe bone deformations during puberty. This patient initially displayed CNS and microcoria, leading to the clinical diagnosis of Pierson syndrome. Genetic analysis revealed a truncating mutation and a splice site mutation of LAMB2. The patient received a renal transplantation (R-Tx) at the age of 3. After R-Tx, renal evolution was simple, the patient receiving low-dose corticosteroids, tacrolimus and mycophenolate mofetil. At the age of 12, bone deformations progressively appeared. At the time of bone impairment, renal function was subnormal (glomerular filtration rate using iohexol clearance 50mL/min per 1.73m²), and parameters of calcium/phosphate metabolism were normal (calcium 2.45mmol/L, phosphorus 1.30mmol/L, PTH 81ng/L, ALP 334U/L, 25OH-D 73nmol/L). Radiographs showed major deformations such as scoliosis, genu varum and diffuse epiphyseal abnormalities. A high resolution scanner (HR-pQCT) was performed, demonstrating a bone of "normal low" quantity and quality; major radial and cubital deformations were observed. Stainings of laminin β2 were performed on bone and renal samples from the patient and healthy controls: as expected, laminin β2 was expressed in the control kidney but not in the patient's renal tissue, and a similar pattern was observed in bone.

CONCLUSION

This is the first case of skeletal impairment ever described in Pierson syndrome. Integrin α3β1, receptor for laminin β2, are found in podocytes and osteoblasts, and the observation of both the presence of laminin β2 staining in healthy bone and its absence in the patient's bone raises the question of a potential role of laminin β2 in bone physiology.

Efficacy and Safety of Rituximab in Children With Steroid- and Cyclosporine-resistant and Steroid- and Cyclosporine-dependent Nephrotic Syndrome

INTRODUCTION

There is evidence of the effectiveness of rituximab in treatment of nephrotic syndrome in children. The present study aimed to assess safety and the therapeutic effectiveness of rituximab in steroid- and cyclosporine-resistant pediatric nephrotic syndrome.

MATERIALS AND METHODS

Forty-three children with steroid- and cyclosporine-resistant or steroid- and cyclosporine-dependent noncongenital nephrotic syndrome were included in the study to receive intravenous rituximab, 375 mg/m2/wk, for 4 weeks. The children were followed up for 2 years. Effectiveness was defined as remission of proteinuria in response to rituximab. Side effects of rituximab were monitored.

RESULTS

Overall, 23 (57.1%) of the children had steroid- and cyclosporine-resistant nephrotic syndrome, of whom 8 (34.8%) revealed complete response and 3 (13%) revealed partial response. Seven children (16.7%) had late-resistant nephrotic syndrome, of whom 6 (85.7%) revealed complete response and none revealed partial response. Ten children (26.2%) had steroid- and cyclosporine-dependence all of whom revealed complete response to rituximab. Complete response rate was significantly higher in those with drug-dependent pattern than the other groups (P = .002). There was no association between response to rituximab and pathological basis of disease. Side effects were found in 4 patients as leukopenia in 2, alopecia in 1, and eosinophilia in 1.

CONCLUSIONS

Rituximab is effective for children with nephrotic syndrome with high efficacy and well tolerability, especially in those with steroid- and cyclosporine-dependent nephrotic syndrome.

REducing STEroids in Relapsing Nephrotic syndrome: the RESTERN study- protocol of a national, double-blind, randomised, placebo-controlled, non-inferiority intervention study

INTRODUCTION

Oral corticosteroids are the first-line treatment for idiopathic childhood nephrotic syndrome. Most children experience several relapses, needing repeated courses of corticosteroid therapy. This exposes them to side effects and long-term complications. For most patients, long-term prognosis is for complete resolution of the disease over time and maintenance of normal kidney function. Therefore, it is vital to focus on minimising adverse events of the disease and its therapy. Unfortunately, no randomised controlled trials are available to determine the optimal corticosteroid treatment of an infrequent relapse of nephrotic syndrome. Recent studies show that treatment schedules for the first episode can safely be shortened to 2 months. The hypothesis of the REducing STEroids in Relapsing Nephrotic syndrome (RESTERN) study is that a 4-week reduction of alternate-day steroids after inducing remission is effective and safe, reduces steroid exposure by 35% on average and is therefore preferable.

METHODS AND ANALYSIS

The RESTERN study is a nationwide, double-blind, randomised, placebo-controlled, non-inferiority intervention study. Children aged 1-18 years with a relapse of steroid-sensitive nephrotic syndrome are eligible for this study. Study subjects (n=144) will be randomly assigned to either current standard therapy in the Netherlands or a reduced prednisolone schedule. The primary outcome of the RESTERN study is the time to first relapse after the final prednisolone dose. The secondary outcomes are the number or relapses, progression to frequent relapsing or steroid dependent nephrotic syndrome and the cumulative dosage of prednisolone during the study period.

ETHICS AND DISSEMINATION

This non-inferiority trial will be performed in accordance with the Declaration of Helsinki and has been approved by the medical ethical committee of Arnhem-Nijmegen and the Dutch Competent Authority (Central Committee on Research Involving Human Subjects, CCMO). After completion of this study, results will be published in national and international peer-reviewed scientific journals. Papers will be published according to CCMO guidelines. The final report will be made available to trial participants.

TRIAL REGISTRATION NUMBER

NTR5670, EudraCT no 2016-002430-76.

Childhood idiopathic steroid-resistant nephrotic syndrome at a Single Center in Khartoum

Prevalence, clinicopathological features, and outcome of childhood idiopathic steroid-resistant nephrotic syndrome (ISRNS) vary in different countries. We report on these parameters in a single center in Khartoum. We retrospectively reviewed all the records of children with idiopathic nephrotic syndrome (INS) followed up in the pediatric renal unit, Soba Hospital, Khartoum between 2001 and 2012. ISRNS was defined as no remission within four weeks of daily prednisolone at a dose of 60 mg/m2. In 430 children with INS 130 (28%) had SRNS with a mean age of 7.7 ± 4.12 years. Males were 78 (60%). At presentation, hematuria was recorded in 57%, hypertension was recorded in 48%, and renal impairment in 15%. Histopathology showed focal segmental glomerulosclerosis in 40.8%, mesangioproliferative glomerulonephritis (22.3%), mesangiocapillary glomerulonephritis (16.9%), minimal change disease (MCD) (16.2%), and membranous glomerulonephritis (3.8%). Therapy included cyclosporine in 38.5%, additional therapy with cyclophosphamide, mycophenolate mofetil or tacrolimus in 20.8%, and steroids ± diuretics ± angiotensin converting enzyme (ACE) inhibitors in 40.7%. After 3.64 ± 2.84 years, 26.8% had complete remission (CR), 18.6% partial remission (PR), 26.8% were unremitting, 21.5% had chronic kidney disease (CKD), 1.6% died, and 4.6% were lost to follow-up. Non-MCD cases had significantly lower CR and higher CKD rates than MCD (P = 0.047 and 0.041, respectively). Cyclosporine ± additional therapy was significantly associated with higher rate of CR than steroids ± ACE inhibitors ± diuretics (P = 0.001), but the prevalence of CKD between the two groups was not significantly different (P = 0.604). Impaired renal function and hypertension at presentation were risk factors for CKD (P = 0.001 and 0.001, respectively). In Sudanese children with ISRNS, non-MCD lesions were the most common lesions. This pattern in addition to the lack of adequate therapy may explain the relatively lower CR and higher CKD rates. Impaired renal function and hypertension at presentation were risk factors for progression to CKD.