A randomized trial of cyclosporine in steroid-resistant idiopathic nephrotic syndrome

Focal Segmental Glomerulosclerosis

Focal segmental glomerular sclerosis (FSGS) is a histological lesion characterized by sclerosis in sections (segmental) of some glomeruli (focal) in association with podocyte injury. Historically, FSGS has often been characterized as a disease, but it is a heterogeneous entity based on etiology, clinical course, and therapeutic approach. A unifying feature is podocyte injury and loss, which can be primary or the result of secondary maladaptive responses to glomerular stressors. FSGS has been demonstrated over time to carry a large health burden and remains a leading glomerular cause of ESRD globally. Recent clinical practice guidelines highlight the unmet scientific need for better understanding of disease pathogenesis, particularly for immunologic etiologies, as well as more targeted therapeutic drug development. In this review, we will discuss the current FSGS classification scheme, pathophysiologic mechanisms of injury, and treatment guidelines, along with emerging and investigational therapeutics.

Kidney outcomes in children with primary focal segmental glomerulosclerosis from a low- and middle- income country

BACKGROUND

Limited data exists regarding the clinical course and outcomes of children with primary focal segmental glomerulosclerosis (FSGS) from low- and middle- income countries.

METHODS

Children aged 1-18 years with biopsy-proven primary FSGS followed from January 2010-June 2023 in a tertiary-care center were enrolled and their clinical profile, histological characteristics, kidney outcomes, and predictors of adverse outcomes were determined.

RESULTS

Over 13 years, 73 (54.8% boys) children with median (IQR) age at FSGS diagnosis 6.7 (3,10) years were recruited and followed up for median 4 (2.5,8) years. FSGS-not otherwise specified (NOS) was the most common histological subtype, in 64 (87.6%) children, followed by collapsing variant in 5 (6.8%) children. At last follow-up, 43 (58.9%), 2 (2.7%) and 28 (38.3%) children were in complete remission (CR), partial remission (PR), and no remission (NR) respectively. Calcineurin inhibitors led to CR or PR in 39 (62%) children. Overall, 21 (28.7%) children progressed to chronic kidney disease (CKD) stage 2-5 (19 from NR vs. 2 from PR group; p = 0.03); with 41% of those NR at 12 months progressing to CKD 4-5 by last follow-up. On multivariable analysis, collapsing variant [adjusted HR 2.5 (95%CI 1.5, 4.17), p = 0.001] and segmental sclerosis > 25% [aHR 9.9 (95%CI 2.2, 45.2), p = 0.003] predicted kidney disease progression.

CONCLUSIONS

In children with FSGS, response to immunosuppression predicts kidney survival as evidenced by nil to lower progression to CKD 2-5 by median follow-up of 4 (2.5,8) years in children with CR and PR, compared to those with no remission at 12 months from diagnosis. Segmental sclerosis > 25% and collapsing variant predicted progression to advanced CKD.

Intravenous cyclophosphamide therapy in children with calcineurin inhibitor-resistant steroid-resistant nephrotic syndrome in a resource-limited setting

BACKGROUND

In pediatric steroid-resistant nephrotic syndrome (SRNS), calcineurin inhibitors (CNIs) are recommended as first-line therapy, with efficacy ranging between 60 and 80%, implying a substantial proportion will exhibit CNI resistance. Which alternate immunosuppressive therapy should be used in non-genetic pediatric SRNS exhibiting CNI resistance is especially relevant in low- to middle-income countries (LMIC), where the prohibitive costs of certain drugs such as monoclonal antibodies often determine therapy choice.

METHODS

The primary objective was to assess the efficacy of intravenous cyclophosphamide in a proportion of children aged 1-18 years with CNI-resistant SRNS with a complete response (CR) or partial response (PR) at 6 months from commencement of pulse therapy. The secondary objectives were to assess the proportion and profile of infections and adverse effects.

RESULTS

Of 90 children with idiopathic SRNS presenting between January 2013 and December 2022, 29 (32.2%) had CNI resistance and were enrolled. They were administered monthly intravenous cyclophosphamide pulses (6 pulses). Median (IQR) duration of follow-up was 48 (29.5, 63.5) months. At the end of 6 months of cyclophosphamide therapy, 13 (44.8%) attained CR and 4 (13.8%) attained PR, with an overall cyclophosphamide success rate of 58.6%. The efficacy of intravenous cyclophosphamide was higher in secondary (9/10; 90%) versus primary CNI resistance (8/19; 42.1%) (p = 0.029). Three children (3/29; 10.3%) developed systemic infections within 12 months of initiation of cyclophosphamide therapy, similar to the rate of systemic infections among children receiving CNI for SRNS management (6/41; 14.6%) (p = 0.85).

CONCLUSIONS

It is prudent to try intravenous cyclophosphamide in CNI-resistant SRNS in LMIC, given the reasonable cost and good efficacy rates (58.6%).

Focal Segmental Glomerulosclerosis: Assessing the Risk of Relapse

Introduction

Kidney outcomes are improved in primary focal segmental glomerulosclerosis (FSGS) by maintaining a remission in proteinuria. However, characteristics associated with relapses are uncertain. We sought to identify these by analyzing each remission.

Methods

We performed a retrospective study in patients with biopsy-proven lesions of FSGS, absent identifiable secondary cause, who had at least 1 remission from nephrotic-range proteinuria. In each patient, we identified every remission, every relapse, and their durations. Using a multilevel logistic regression to account for the clustering of multiple remissions within a patient, we tested which clinical characteristics were independently associated with relapses.

Results

In 203 individuals, 312 remissions occurred, 177 with and 135 without relapse. A minority of remissions were atypical, defined by either absent hypoalbuminemia and/or no immunosuppression (IS), in contrast to the classic nephrotic syndrome that remits with IS. Atypical remission variants were just as likely to relapse as the classical presentation. Only 24% of remission events were on maintenance therapy at relapse. Independent characteristics associated with relapses were higher maximal proteinuria while nephrotic; and in remission, higher nadir proteinuria, lower serum albumin, and higher blood pressure. Using these variables, we created a tool estimating the 1-year risk of relapse ranging from 9% to 80%, well-calibrated to the observed data.

Conclusion

In FSGS, relapses are frequent but predictable using independent clinical characteristics. We also provide evidence that atypical presentations remit and relapse following the same pattern as classic FSGS presentations. Treatment strategies to prolong remission duration should be addressed in future trials.

Current understanding of the molecular mechanisms of circulating permeability factor in focal segmental glomerulosclerosis

The pathogenetic mechanisms underlying the onset and the post-transplant recurrence of primary focal segmental glomerulosclerosis (FSGS) are complex and remain yet to be fully elucidated. However, a growing body of evidence emphasizes the pivotal role of the immune system in both initiating and perpetuating the disease. Extensive investigations, encompassing both experimental models and patient studies, have implicated T cells, B cells, and complement as crucial actors in the pathogenesis of primary FSGS, with various molecules being proposed as potential "circulating factors" contributing to the disease and its recurrence post kidney-transplantation. In this review, we critically assessed the existing literature to identify essential pathways for a comprehensive characterization of the pathogenesis of FSGS. Recent discoveries have shed further light on the intricate interplay between these mechanisms. We present an overview of the current understanding of the engagement of distinct molecules and immune cells in FSGS pathogenesis while highlighting critical knowledge gaps that require attention. A thorough characterization of these intricate immune mechanisms holds the potential to identify noninvasive biomarkers that can accurately identify patients at high risk of post-transplant recurrence. Such knowledge can pave the way for the development of targeted and personalized therapeutic approaches in the management of FSGS.

Role of cyclosporin A in the treatment of kidney disease and nephrotoxicity

The clinical use of cyclosporin A (CsA) has led to significant advances and achievements in the field of transplantation and immune diseases. However, the nephrotoxicity of CsA is a major concern in current immunosuppression regimens. CsA causes abnormal kidney function while treating kidney disease, causing problems for clinicians and patients. Evidence of CsA nephrotoxicity is almost always present in transplant recipients after long-term CsA administration (up to 10 years), and similar phenomena occur with other calcineurin inhibitors. In this review, we summarize the mechanisms and influencing factors of CsA for the treatment of primary nephrotic syndrome. The mechanisms of CsA nephrotoxicity, clinical-pathological features, diagnosis, prevention strategies, and risk factors are summarized. We discuss the correlates and mechanisms of the switch between kidney disease prevention and nephrotoxicity of CsA to better understand the function of CsA in the kidney and to provide a basis for the prevention and treatment of CsA nephrotoxicity.

Outcomes of steroid-resistant nephrotic syndrome in children not treated with intensified immunosuppression

BACKGROUND

The aim of the current PodoNet registry analysis was to evaluate the outcome of steroid-resistant nephrotic syndrome (SRNS) in children who were not treated with intensified immunosuppression (IIS), focusing on the potential for spontaneous remission and the role of angiotensin blockade on proteinuria reduction.

METHODS

Ninety-five pediatric patients who did not receive any IIS were identified in the PodoNet Registry. Competing risk analyses were performed on 67 patients with nephrotic-range proteinuria at disease onset to explore the cumulative rates of complete or partial remission or progression to kidney failure, stratified by underlying etiology (genetic vs. non-genetic SRNS). In addition, Cox proportional hazard analysis was performed to identify factors predicting proteinuria remission.

RESULTS

Eighteen of 31 (58.1%) patients with non-genetic SRNS achieved complete remission without IIS, with a cumulative likelihood of 46.2% at 1 year and 57.7% at 2 years. Remission was sustained in 11 children, and only two progressed to kidney failure. In the genetic subgroup (n = 27), complete resolution of proteinuria occurred very rarely and was never sustained; 6 (21.7%) children progressed to kidney failure at 3 years. Almost all children (96.8%) received proteinuria-lowering renin-angiotensin-aldosterone system (RAAS) antagonist treatment. On antiproteinuric treatment, partial remission was achieved in 7 of 31 (22.6%) children with non-genetic SRNS and 9 of 27 children (33.3%) with genetic SRNS.

CONCLUSION

Our results demonstrate that spontaneous complete remission can occur in a substantial fraction of children with non-genetic SRNS and milder clinical phenotype. RAAS blockade increases the likelihood of partial remission of proteinuria in all forms of SRNS. A higher resolution version of the Graphical abstract is available as Supplementary information.

Interventions for minimal change disease in adults with nephrotic syndrome

BACKGROUND

Steroids have been used widely since the early 1970s for the treatment of adult-onset minimal change disease (MCD). Recently, newer agents have been used in adult MCD aiming to reduce the risk of adverse effects. The response rates to immunosuppressive agents in adult MCD are more variable than in children. The optimal agent, dose, and duration of treatment for the first episode of nephrotic syndrome, or for disease relapse(s) have not been determined. This is an update of a review first published in 2008.

OBJECTIVES

We aimed to 1) evaluate the benefits and harms of different agents, including both immunosuppressive and non-immunosuppressive agents, in adults with MCD causing the nephrotic syndrome; and 2) evaluate the efficacy of interventions on 'time-to-remission' of nephrotic syndrome, in adults with MCD causing the nephrotic syndrome.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 21 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any intervention for MCD with nephrotic syndrome in adults over 18 years were included. Studies comparing different types, routes, frequencies, and duration of immunosuppressive agents and non-immunosuppressive agents were assessed.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random-effects model and results were expressed as a risk ratio (RR) for dichotomous outcomes, or mean difference (MD) for continuous data with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Fifteen RCTs (769 randomised participants) were identified; four studies evaluated different prednisolone regimens, eight studies evaluated the calcineurin inhibitors (CNIs) (tacrolimus or cyclosporin), two studies evaluated enteric-coated mycophenolate sodium (EC-MPS) and one study evaluated levamisole. In all but two studies of non-corticosteroid agents, reduced-dose prednisolone was given with the treatment agent and the comparator was high-dose prednisolone. In the risk of bias assessment, 11 and seven studies were at low risk of bias for sequence generation and allocation concealment, respectively. No studies were at low risk of performance bias and eight studies were at low risk of detection bias. Thirteen, 10 and six studies were at low risk of attrition bias, reporting bias and other bias, respectively. Compared with no specific treatment, it is uncertain whether prednisolone increases the number with complete remission (1 study, 28 participants: RR 1.44, 95% CI 0.95 to 2.19), complete or partial remission (1 study, 28 participants: RR 1.38, 95% CI 0.98 to 1.95), subsequent relapse (1 study, 28 participants: RR 0.75, 95% CI 0.48 to 1.17), or reduces the adverse effects because the certainty of the evidence is very low. Compared with oral prednisolone alone, it is uncertain whether intravenous methylprednisolone and prednisolone increase the number with complete remission (2 studies, 35 participants: RR 1.76, 95% CI 0.17 to 18.32; I² = 90%), relapse (two studies, 19 participants. RR 1.18, 95% CI 0.65 to 2.15; I² = 0%) or adverse events because the certainty of the evidence is very low. Compared with prednisolone alone, CNIs with reduced-dose prednisolone or without prednisolone probably make little or no difference to the number achieving complete remission (8 studies; 492 participants: RR 0.99, 95% CI 0.93 to 1.05; I² = 0%), complete or partial remission (4 studies, 269 participants: RR 1.01, 95% CI 0.96 to 1.05; I² = 0%), or relapse (7 studies; 422 participants: RR 0.73, 95% CI 0.51 to 1.03; I² = 0%) (moderate certainty evidence), may reduce the risk of obesity or Cushing's Syndrome (5 studies; 388 participants: RR 0.11, 95% CI 0.02 to 0.59; I² = 45%) and the risk of acne (4 studies; 270 participants: RR 0.15, 95% CI 0.03 to 0.67; I² = 0%) (low certainty evidence); and had uncertain effects on diabetes or hyperglycaemia, hypertension, and acute kidney injury (AKI) (low certainty evidence). Compared with prednisolone alone, EC-MPS with reduced-dose prednisolone probably make little or no difference to the number undergoing complete remission at 4 weeks (1 study, 114 participants: RR 1.12, 95% CI 0.84 to 1.50), and at 24 weeks probably make little or no difference to the number undergoing complete remission (2 studies, 134 participants: RR 1.12, 95% CI 0.84 to 1.38; I² = 0%) (moderate certainty evidence), complete or partial remission (2 studies 134 participants: RR 0.92, 95% CI 0.75 to 1.12; I² = 0%), relapse (2 studies, 83 participants: RR 0.50, 95% CI 0.07 to 3.74; I² = 56%) (low certainty evidence); or to the adverse events of new-onset glucose intolerance, death, or AKI (low certainty evidence). One study (24 participants) compared levamisole and prednisolone with prednisolone in patients with relapsing disease. The authors identified no differences in mean relapse rate or adverse effects but no standard deviations were provided.

AUTHORS' CONCLUSIONS

This updated review has identified evidence for the efficacy and adverse effects of CNIs and EC-MPS with or without reduced-dose prednisolone compared with prednisolone alone for the induction of remission in adults with MCD and nephrotic syndrome with some reductions in steroid-associated adverse events. RCT data on the efficacy and adverse effects of rituximab in adults with MCD are awaited. Further, adequately powered RCTs are required to determine the relative efficacies of CNIs and EC-MPS and to evaluate these medications in patients with relapsing or steroid-resistant disease.

Interventions for focal segmental glomerulosclerosis in adults

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) can be separated into primary, genetic or secondary causes. Primary disease results in nephrotic syndrome while genetic and secondary forms may be associated with asymptomatic proteinuria or with nephrotic syndrome. Overall only about 20% of patients with FSGS experience a partial or complete remission of nephrotic syndrome with treatment. FSGS progresses to kidney failure in about half of the cases. This is an update of a review first published in 2008.

OBJECTIVES

To assess the benefits and harms of immunosuppressive and non-immunosuppressive treatment regimens in adults with FSGS.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies to 21 June 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any intervention for FSGS in adults were included. Studies comparing different types, routes, frequencies, and duration of immunosuppressive agents and non-immunosuppressive agents were assessed.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random-effects model and results were expressed as a risk ratio (RR) for dichotomous outcomes, or mean difference (MD) for continuous data with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Fifteen studies (560 participants) were included. No studies specifically evaluating corticosteroids compared with placebo or supportive therapy were identified. Studies evaluated participants with steroid-resistant FSGS. Five studies (240 participants) compared cyclosporin with or without prednisone with different comparators (no specific treatment, prednisone, methylprednisolone, mycophenolate mofetil (MMF), dexamethasone). Three small studies compared monoclonal antibodies (adalimumab, fresolimumab) with other agents or placebo. Six single small studies compared rituximab with tacrolimus, cyclosporin plus valsartan with cyclosporin alone, MMF with prednisone, chlorambucil plus methylprednisolone and prednisone with no specific treatment, different regimens of dexamethasone and CCX140-B (an antagonist of the chemokine receptor CCR2) with placebo. The final study (109 participants) compared sparsentan, a dual inhibitor of endothelin Type A receptor and of the angiotensin II Type 1 receptor, with irbesartan. In the risk of bias assessment, seven and five studies were at low risk of bias for sequence generation and allocation concealment, respectively. Four studies were at low risk of performance bias and 14 studies were at low risk of detection bias. Thirteen, six and five studies were at low risk of attrition bias, reporting bias and other bias, respectively. Of five studies evaluating cyclosporin, four could be included in our meta-analyses (231 participants). Cyclosporin with or without prednisone compared with different comparators may increase the likelihood of complete remission (RR 2.31, 95% CI 1.13 to 4.73; I² = 1%; low certainty evidence) and of complete or partial remission (RR 1.64, 95% CI 1.10 to 2.44; I² = 19%) but not of partial remission (RR 1.36, 95% CI 0.78 to 2.39, I² = 22%). In Individual studies, cyclosporin with prednisone versus prednisone may increase the likelihood of partial (49 participants: RR 7.96, 95% CI 1.09 to 58.15) or complete or partial remission (49 participants: RR 8.85, 95% CI 1.22 to 63.92) but not of complete remission. The remaining individual comparisons may make little or no difference to the likelihood of complete remission, partial remission or complete or partial remission compared with no treatment, methylprednisolone, MMF, or dexamethasone. Individual study data and combined data showed that cyclosporin may make little or no difference to the outcomes of chronic kidney disease or kidney failure. It is uncertain whether cyclosporin compared with these comparators in individual or combined analyses makes any difference to the outcomes of hypertension or infection. MMF compared with prednisone may make little or no difference to the likelihood of complete remission (33 participants: RR 1.05, 95% CI 0.58 to 1.88; low certainty evidence), partial remission, complete or partial remission, glomerular filtration rate, or infection. It is uncertain whether other interventions make any difference to outcomes as the certainty of the evidence is very low. It is uncertain whether sparsentan reduces proteinuria to a greater extent than irbesartan.

AUTHORS' CONCLUSIONS

No RCTs, which evaluated corticosteroids, were identified although the KDIGO guidelines recommend corticosteroids as the first treatment for adults with FSGS. The studies identified included participants with steroid-resistant FSGS. Treatment with cyclosporin for at least six months was more likely to achieve complete remission of proteinuria compared with other treatments but there was considerable imprecision due to few studies and small participant numbers. In future studies of existing or new interventions, the investigators must clearly define the populations included in the study to provide appropriate recommendations for patients with primary, genetic or secondary FSGS.

The role of the immune system in idiopathic nephrotic syndrome

Idiopathic nephrotic syndrome (INS) in children is characterized by massive proteinuria and hypoalbuminemia and usually responds well to steroids. However, relapses are frequent, which can require multi-drug therapy with deleterious long-term side effects. In the last decades, different hypotheses on molecular mechanisms underlying INS have been proposed and several lines of evidences strongly indicate a crucial role of the immune system in the pathogenesis of non-genetic INS. INS is traditionally considered a T-cell-mediated disorder triggered by a circulating factor, which causes the impairment of the glomerular filtration barrier and subsequent proteinuria. Additionally, the imbalance between Th17/Tregs as well as Th2/Th1 has been implicated in the pathomechanism of INS. Interestingly, B-cells have gained attention, since rituximab, an anti-CD20 antibody demonstrated a good therapeutic response in the treatment of INS. Finally, recent findings indicate that even podocytes can act as antigen-presenting cells under inflammatory stimuli and play a direct role in activating cellular pathways that cause proteinuria. Even though our knowledge on the underlying mechanisms of INS is still incomplete, it became clear that instead of a traditionally implicated cell subset or one particular molecule as a causative factor for INS, a multi-step control system including soluble factors, immune cells, and podocytes is necessary to prevent the occurrence of INS. This present review aims to provide an overview of the current knowledge on this topic, since advances in our understanding of the immunopathogenesis of INS may help drive new tailored therapeutic approaches forward.

Immunosuppressive treatment for primary membranous nephropathy in adults with nephrotic syndrome

BACKGROUND

Primary membranous nephropathy (PMN) is a common cause of nephrotic syndrome in adults. Without treatment, approximately 30% of patients will experience spontaneous remission and one third will have persistent proteinuria. Approximately one-third of patients progress toward end-stage kidney disease (ESKD) within 10 years. Immunosuppressive treatment aims to protect kidney function and is recommended for patients who do not show improvement of proteinuria by supportive therapy, and for patients with severe nephrotic syndrome at presentation due to the high risk of developing ESKD. The efficacy and safety of different immunosuppressive regimens are unclear. This is an update of a Cochrane review, first published in 2004 and updated in 2013.

OBJECTIVES

The aim was to evaluate the safety and efficacy of different immunosuppressive treatments for adult patients with PMN and nephrotic syndrome.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 1 April 2021 with support from the Cochrane Kidney and Transplant Information Specialist using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) investigating effects of immunosuppression in adults with PMN and nephrotic syndrome were included.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, quality assessment, and data synthesis were performed using Cochrane-recommended methods. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Sixty-five studies (3807 patients) were included. Most studies exhibited a high risk of bias for the domains, blinding of study personnel, participants and outcome assessors, and most studies were judged unclear for randomisation sequence generation and allocation concealment. Immunosuppressive treatment versus placebo/no treatment/non-immunosuppressive treatment In moderate certainty evidence, immunosuppressive treatment probably makes little or no difference to death, probably reduces the overall risk of ESKD (16 studies, 944 participants: RR 0.59, 95% CI 0.35 to 0.99; I² = 22%), probably increases total remission (complete and partial) (6 studies, 879 participants: RR 1.44, 95% CI 1.05 to 1.97; I² = 73%) and complete remission (16 studies, 879 participants: RR 1.70, 95% CI 1.05 to 2.75; I² = 43%), and probably decreases the number with doubling of serum creatinine (SCr) (9 studies, 447 participants: RR 0.46, 95% CI 0.26 to 0.80; I² = 21%). However, immunosuppressive treatment may increase the number of patients relapsing after complete or partial remission (3 studies, 148 participants): RR 1.73, 95% CI 1.05 to 2.86; I² = 0%) and may lead to a greater number experiencing temporary or permanent discontinuation/hospitalisation due to adverse events (18 studies, 927 participants: RR 5.33, 95% CI 2.19 to 12.98; I² = 0%). Immunosuppressive treatment has uncertain effects on infection and malignancy. Oral alkylating agents with or without steroids versus placebo/no treatment/steroids Oral alkylating agents with or without steroids had uncertain effects on death but may reduce the overall risk of ESKD (9 studies, 537 participants: RR 0.42, 95% CI 0.24 to 0.74; I² = 0%; low certainty evidence). Total (9 studies, 468 participants: RR 1.37, 95% CI 1.04 to 1.82; I² = 70%) and complete remission (8 studies, 432 participants: RR 2.12, 95% CI 1.33 to 3.38; I² = 37%) may increase, but had uncertain effects on the number of patients relapsing, and decreasing the number with doubling of SCr. Alkylating agents may be associated with a higher rate of adverse events leading to discontinuation or hospitalisation (8 studies 439 participants: RR 6.82, 95% CI 2.24 to 20.71; I² = 0%). Oral alkylating agents with or without steroids had uncertain effects on infection and malignancy. Calcineurin inhibitors (CNI) with or without steroids versus placebo/no treatment/supportive therapy/steroids We are uncertain whether CNI with or without steroids increased or decreased the risk of death or ESKD, increased or decreased total or complete remission, or reduced relapse after complete or partial remission (low to very low certainty evidence). CNI also had uncertain effects on decreasing the number with a doubling of SCr, temporary or permanent discontinuation or hospitalisation due to adverse events, infection, or malignancy. Calcineurin inhibitors (CNI) with or without steroids versus alkylating agents with or without steroids We are uncertain whether CNI with or without steroids increases or decreases the risk of death or ESKD. CNI with or without steroids may make little or no difference to total remission (10 studies, 538 participants: RR 1.01, 95% CI 0.89 to 1.15; I² = 53%; moderate certainty evidence) or complete remission (10 studies, 538 participants: RR 1.15, 95% CI 0.84 to 1.56; I² = 56%; low certainty evidence). CNI with or without steroids may increase relapse after complete or partial remission. CNI with or without steroids had uncertain effects on SCr increase, adverse events, infection, and malignancy. Other immunosuppressive treatments Other interventions included azathioprine, mizoribine, adrenocorticotropic hormone, traditional Chinese medicines, and monoclonal antibodies such as rituximab. There were insufficient data to draw conclusions on these treatments.

AUTHORS' CONCLUSIONS

This updated review strengthened the evidence that immunosuppressive therapy is probably superior to non-immunosuppressive therapy in inducing remission and reducing the number of patients that progress to ESKD. However, these benefits need to be balanced against the side effects of immunosuppressive drugs. The number of included studies with high-quality design was relatively small and most studies did not have adequate follow-up. Clinicians should inform their patients of the lack of high-quality evidence. An alkylating agent (cyclophosphamide or chlorambucil) combined with a corticosteroid regimen had short- and long-term benefits, but this was associated with a higher rate of adverse events. CNI (tacrolimus and cyclosporin) showed equivalency with alkylating agents however, the certainty of this evidence remains low. Novel immunosuppressive treatments with the biologic rituximab or use of adrenocorticotropic hormone require further investigation and validation in large and high-quality RCTs.

Calcineurin inhibitors in nephrotic syndrome secondary to podocyte gene mutations: a systematic review

BACKGROUND

Calcineurin inhibitor (CNI) use in genetic steroid-resistant nephrotic syndrome (SRNS) is controversial as response rate is reported to be lower than non-genetic disease and no plausible mechanism of action is known.

METHODS

We reviewed PubMed for publications on CNI use in hereditary SRNS to determine (1) CNI response rate; (2) impact of response on renal outcome; and (3) clinical and molecular predictors of response. Variant pathogenicity was assessed according to American College of Medical Genetics criteria and patients were assigned to 1 of 4 categories based on estimated genotype contribution to phenotype. Cases with non-existing phenotype-to-genotype contribution were excluded. Subgroup analysis was performed for the possible and confirmed genetic cases.

RESULTS

Data of 178 genetic SRNS cases from 22 studies were analyzed; 35% responded (fully or partially) to CNI with minimal change being the commonest biopsy pattern among responders. Full responders had superior kidney survival compared with partial and non-responders (log-rank test χ² = 10.7; P < 0.01). WT1 variant carriers were most likely to respond to CNI compared with any other mutation [OR 4.7 (2.0-11.3); P < 0.01].

CONCLUSIONS

These findings support the current recommendation for using CNI as first-line treatment for children with SRNS whilst genetic analyses are pending. This would allow assessment of treatment response even in cases later established as genetic ensuring that benefits on kidney function are balanced with treatment toxicity.

Steroid resistant focal segmental glomerulosclerosis: effect of arterial hyalinosis on outcome: single center study

Background. Few data with adequate evidence exists as regards the effect of Cyclosporine (CsA) and mycophenolate mofetil (MMF) on pathological prognostic parameters in patients with steroid resistant focal segmental glomerulosclerosis (FSGS). The purpose of the present study is to compare the effect of cyclosporin and mycophenolate mofetil in addition to steroids on functional and histopathologic renal parameters in patients with steroid resistant FSGS one year after treatment.Material and methods. Thirty-seven adults with primary FSGS patients resistant to steroid therapy consecutively randomized to treatment with either MMF or cyclosporine. Low dose prednisolone added to both groups. Glomerular filtration rate (GFR) and blood pressure (BP) were determined at all examinations and a second renal biopsy was taken 12 months after treatment with either of cyclosporin and mycophenolate mofetil.Results. GFR significantly increased in MMF group p < 0.01 after 6 months and unchanged after 12 months. On the other hand, GFR significantly decrease in CsA group p < 0.001 after 6 months and reduced more after 12 months p < 0.001 compared to base line levels. There was a significant difference of GFR between the 2 groups at 6 months p < 0.001. The extent of proteinuria decreased significantly in CsA group after 12 months p < 0.001. The extent of arteriolar hyalinosis increased significantly in CsA group (0.78 to 1.81 score, p < 0.001) but was unchanged in MMF group (0.93 to 0.96 score), whereas interstitial fibrosis increased to same level in both groups (grade 3).Conclusion. Conversion to MMF in those patients may be superior to CsA as regards GFR after 12 months after treatment in spite of the presence of greater level of protein excretion. The increased arteriolar hyalinosis during CsA treatment most likely results in higher BP compared to MMF treatment in patients with FSGS resistant to steroids.

Autoimmunity in Focal Segmental Glomerulosclerosis: A Long-Standing Yet Elusive Association

Focal segmental glomerulosclerosis (FSGS) is a histological term that describes a pathologic renal entity affecting both adults and children, with a wide array of possible underlying etiologies. Podocyte damage with scarring, the hallmark of this condition, leads to altered permeability of the glomerular barrier, which may result in massive proteinuria and relentless renal function deterioration. A definite cause of focal segmental glomerulosclerosis can be confirmed in a minority of cases, while most forms have been traditionally labeled as primary or idiopathic. Despite this definition, increasing evidence indicates that primary forms are a heterogenous group rather than a single disease entity: several circulating factors that may affect glomerular permeability have been proposed as potential culprits, and both humoral and cellular immunity have been implicated in the pathogenesis of the disease. Consistently, immunosuppressive drugs are considered as the cornerstone of treatment for primary focal segmental glomerulosclerosis, but response to these agents and long-term outcomes are highly variable. In this review we provide a summary of historical and recent advances on the pathogenesis of primary focal segmental glomerulosclerosis, focusing on implications for its differential diagnosis and treatment.

Podocytopathies

Podocytopathies are kidney diseases in which direct or indirect podocyte injury drives proteinuria or nephrotic syndrome. In children and young adults, genetic variants in >50 podocyte-expressed genes, syndromal non-podocyte-specific genes and phenocopies with other underlying genetic abnormalities cause podocytopathies associated with steroid-resistant nephrotic syndrome or severe proteinuria. A variety of genetic variants likely contribute to disease development. Among genes with non-Mendelian inheritance, variants in APOL1 have the largest effect size. In addition to genetic variants, environmental triggers such as immune-related, infection-related, toxic and haemodynamic factors and obesity are also important causes of podocyte injury and frequently combine to cause various degrees of proteinuria in children and adults. Typical manifestations on kidney biopsy are minimal change lesions and focal segmental glomerulosclerosis lesions. Standard treatment for primary podocytopathies manifesting with focal segmental glomerulosclerosis lesions includes glucocorticoids and other immunosuppressive drugs; individuals not responding with a resolution of proteinuria have a poor renal prognosis. Renin-angiotensin system antagonists help to control proteinuria and slow the progression of fibrosis. Symptomatic management may include the use of diuretics, statins, infection prophylaxis and anticoagulation. This Primer discusses a shift in paradigm from patient stratification based on kidney biopsy findings towards personalized management based on clinical, morphological and genetic data as well as pathophysiological understanding.

IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome

Idiopathic nephrotic syndrome newly affects 1-3 per 100,000 children per year. Approximately 85% of cases show complete remission of proteinuria following glucocorticoid treatment. Patients who do not achieve complete remission within 4-6 weeks of glucocorticoid treatment have steroid-resistant nephrotic syndrome (SRNS). In 10-30% of steroid-resistant patients, mutations in podocyte-associated genes can be detected, whereas an undefined circulating factor of immune origin is assumed in the remaining ones. Diagnosis and management of SRNS is a great challenge due to its heterogeneous etiology, frequent lack of remission by further immunosuppressive treatment, and severe complications including the development of end-stage kidney disease and recurrence after renal transplantation. A team of experts including pediatric nephrologists and renal geneticists from the International Pediatric Nephrology Association (IPNA), a renal pathologist, and an adult nephrologist have now developed comprehensive clinical practice recommendations on the diagnosis and management of SRNS in children. The team performed a systematic literature review on 9 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, formulated recommendations and formally graded them at a consensus meeting, with input from patient representatives and a dietician acting as external advisors and a voting panel of pediatric nephrologists. Research recommendations are also given.

Focal Segmental Glomerulosclerosis: State-of-the-Art and Clinical Perspective

Focal segmental glomerulosclerosis (FSGS) is a histological pattern of glomerular injury, rather than a single disease, that is caused by diverse clinicopathological entities with different mechanisms of injury with the podocyte as the principal target of lesion, leading to the characteristic sclerotic lesions in parts (i.e., focal) of some (i.e., segmental) glomeruli. The lesion of FSGS has shown an increasing prevalence over the past few decades and is considered the most common glomerular cause leading to ESKD. Primary FSGS, which usually presents with nephrotic syndrome, is thought to be caused by circulating permeability factors that have a main role in podocyte foot process effacement. Secondary forms of FSGS include maladaptive FSGS secondary to glomerular hyperfiltration such as in obesity or in cases of loss in nephron mass, virus-associated FSGS, and drug-associated FSGS that can result in direct podocyte injury. Genetic FSGS is increasingly been recognized and a careful evaluation of patients with atypical primary or secondary FSGS should be performed to exclude genetic causes. Unlike primary FSGS, secondary and genetic forms of FSGS do not respond to immunosuppression and tend not to recur after kidney transplantation. Distinguishing primary FSGS from secondary and genetic causes has a prognostic significance and is crucial for an appropriate management. In this review, we examine the pathogenesis, clinical approach to distinguish between the different causes, and current recommendations in the management of FSGS.

Rituximab in maintaining remission in adults with podocytopathy

Rituximab is currently used after the conventional agents have failed in the management of steroid-dependent (SD)/ steroid-resistant (SR) podocytopathies and have a safer toxicity profile. We report 53 adults with podocytopathies who were managed effectively with CD19-targeted rituximab therapy.

METHODS

This was a prospective study carried out at a tertiary care centre in India between January 2014 and June 2019. Adults between 16 and 60 years with SD, frequently relapsing (FR), and SR nephrotic syndrome (NS) due to podocytopathy received rituximab in a CD19-targeted approach.

PRIMARY OUTCOME

Percentage of patients who were in remission at 6 and 12 months. Secondary outcome: Percentage of patients in remission at the last follow-up, rituximab dose and adverse events of rituximab therapy.

RESULTS

Fifty-three adults with SD/FR/SR NS received CD19-targeted rituximab. The median age at the time of first rituximab injection was 30.09 ± 13.21 (16.53) years. At the time of first rituximab infusion, all patients were in remission with steroids and/or calcineurin inhibitors (CNIs). Fifty (94.33%) patients were in remission at the end of 6 and 12 months and the last follow-up (median: 36 months). The mean total dose of rituximab at 1 year was 788.7 ± 128.1 (6 001 100) mg. At last follow-up (median 36 months), 42 (79%) patients did not require any additional CNI or steroids therapy. No serious adverse events to rituximab were noted.

CONCLUSION

CD19-targeted rituximab therapy is safe and efficacious in the management of SD/SR adult podocytopathy. Also, rituximab is effective in maintaining remission in treatment naïve adult SD or FR podocytopathy.

Interventions for idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

The majority of children who present with their first episode of nephrotic syndrome achieve remission with corticosteroid therapy. Children who fail to respond to corticosteroids in the first episode of nephrotic syndrome (initial resistance) or develop resistance after one or more responses to corticosteroids (delayed resistance) may be treated with immunosuppressive agents including calcineurin inhibitors (CNI) (cyclosporin or tacrolimus) and with non-immunosuppressive agents such as angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). However, response to these agents is limited so newer agents are being assessed for efficacy. This is an update of a review first published in 2004 and updated in 2006, 2010 and 2016.

OBJECTIVES

To evaluate the benefits and harms of different interventions used in children with idiopathic nephrotic syndrome, who do not achieve remission following four weeks or more of daily corticosteroid therapy.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies to 17 September 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs were included if they compared different immunosuppressive agents or non-immunosuppressive agents with placebo, prednisone or other agent given orally or parenterally in children aged three months to 18 years with steroid-resistant nephrotic syndrome (SRNS). Studies, which enrolled children and adults but in which paediatric data could not be separated from adult data, were also included.

DATA COLLECTION AND ANALYSIS

Two authors independently searched the literature, determined study eligibility, assessed risk of bias and extracted data. For dichotomous outcomes, results were expressed as risk ratios (RR) and 95% confidence intervals (CI). For continuous outcomes, results were expressed as mean difference (MD) and 95% CI. Data were pooled using the random effects model. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Twenty-five studies (1063 participants) were included. Fourteen studies were at low risk of bias for sequence generation and allocation concealment. Five and 19 studies were at low risk of performance and detection bias. Fourteen, 14 and 13 studies were at low risk of attrition bias, reporting bias and other bias respectively. Cyclosporin compared with placebo or no treatment may increase the number of participants who achieve complete remission (4 studies, 74 participants: RR 3.50, 95% CI 1.09 to 11.20) or complete or partial remission (4 studies, 74 children: RR 3.15, 95% CI 1.04 to 9.57) by 6 months (low certainty evidence). It is uncertain whether cyclosporin increases the likelihood of worsening hypertension or reduces the likelihood of end-stage kidney disease (very low certainty evidence). CNI compared with IV cyclophosphamide (CPA) may increase the number of participants with complete or partial remission at 3 to 6 months (2 studies, 156 children: RR 1.98, 95% CI 1.25 to 3.13) (low certainty evidence) and probably reduces the number with treatment failure (non response, serious infection, persistently elevated creatinine (1 study, 124 participants: RR 0.32, 95% CI 0.18 to 0.58) (moderate certainty evidence) with little or no increase in serious infections (1 study, 131 participants: RR 0.49, 95% CI 0.16 to 1.56) (moderate certainty evidence). Tacrolimus compared with cyclosporin may make little or no difference to the number who achieve complete or partial remission (2 studies, 58 participants: RR 1.05, 95% CI 0.87 to 1.25) (low certainty evidence) or in the number with worsening hypertension (2 studies, 58 participants: RR 0.41, 95% CI 0.08 to 2.15) (low certainty evidence). Cyclosporin compared with mycophenolate mofetil (MMF) and dexamethasone probably makes little or no difference to the number who achieve complete or partial remission (1 study, 138 participants: RR 2.14, 95% CI 0.87 to 5.24) (moderate certainty evidence) and makes little or no difference to the number dying (1 study, 138 participants: RR 2.14, 95% CI 0.87 to 5.24) or with 50% reduction in glomerular filtration rate (GFR) (1 study, 138 participants: RR 2.29, 95% CI 0.46 to 11.41) (low certainty evidence). Among children, who have achieved complete remission, tacrolimus compared with MMF may increase the number of children who maintain complete or partial response for 12 months (1 study, 60 children: RR 2.01, 95% CI 1.32 to 3.07) (low certainty evidence). Oral CPA with prednisone compared with prednisone alone may make little or no difference to the number who achieve complete remission (2 studies, 84 children: RR 1.06, 95% CI 0.61 to 1.87) (low certainty evidence). IV CPA compared with oral CPA (2 studies, 61 children: RR 1.58, 95% CI 0.65 to 3.85) and IV compared with oral CPA plus IV dexamethasone (1 study, 49 children: RR 1.13, 95% CI 0.65 to 1.96) may make little or no difference to the number who achieve complete remission (low certainty evidence). It is uncertain whether rituximab and cyclosporin compared with cyclosporin increases the likelihood of remission because the certainty of the evidence is very low. It is uncertain whether adalimumab or galactose compared with conservative therapy increases the likelihood of remission because the certainty of the evidence is very low. Two studies reported that ACEi may reduce proteinuria in children with SRNS. One study reported that the dual angiotensin II and endothelin Type A receptor antagonist, sparsentan, may reduce proteinuria more effectively than the angiotensin receptor blocker, irbesartan.

AUTHORS' CONCLUSIONS

To date RCTs have demonstrated that CNIs may increase the likelihood of complete or partial remission compared with placebo/no treatment or CPA. For other regimens assessed, it remains uncertain whether the interventions alter outcomes because the certainty of the evidence is low. Further adequately powered, well designed RCTs are needed to evaluate other regimens for children with idiopathic SRNS. Since SRNS represents a spectrum of diseases, future studies should enrol children from better defined groups of patients with SRNS.

Efficacy and safety of cyclosporine a for patients with steroid-resistant nephrotic syndrome: a meta-analysis

BACKGROUND

The purpose of this study was to determine efficacy and safety of cyclosporine A (CsA) for patients with steroid-resistant nephrotic syndrome (SRNS).

METHODS

The Cochrane Library and PubMed were searched to extract the associated studies on Oct 10, 2018, and the meta-analysis method was used to pool and analyze the applicable investigations included in this study. The P(opulation) I(ntervention) C(omparison) O(utcome) of the study were defined as follows: P: Patients with SRNS; I: treated with CsA, cyclophosphamide (CYC), tacrolimus (TAC) or placebo/not treatment (P/NT); C: CsA vs. placebo/nontreatment (P/NT), CsA vs. CYC, CsA vs. TAC; O: complete remission (CR), total remission (TR; complete or partial remission (PR)), urine erythrocyte number, proteinuria levels, albumin, proteinuria, serum creatinine, and plasma cholesterol, etc. Data were extracted and pooled using RevMan 5.3.

RESULTS

In the therapeutic regimen of CsA vs. placebo/nontreatment (P/NT), the results indicated that the CsA group had high values of CR, TR, and low values of proteinuria, serum creatinine, and plasma cholesterol when compared with those in the placebo group. In comparing CsA vs. cyclophosphamide (CYC), the results indicated that the CsA group had higher TR than the CYC group. In comparing CsA vs. tacrolimus (TAC), the results revealed insignificant differences in CR, and TR between the CsA and TAC groups. The safety of CsA was also assessed. The incidence of gum hyperplasia in CsA group was higher than that in the P/NT group, with no differences in incidence of infections or hypertension between CsA and P/NT groups. There was no difference in the incidence of hypertension between the CsA and TAC groups.

CONCLUSIONS

CsA is an effective and safe agent in the therapy of patients with SRNS.

Steroid-resistentes nephrotisches Syndrom

Das steroid-resistente nephrotische Syndrom (SRNS) mit dem histomorphologischen Korrelat der fokal-segmentalen Glomerulosklerose (FSGS) stellt eine bedeutende Ursache für eine terminale Niereninsuffizienz im Kindesalter, aber auch bei erwachsenen Patienten dar. Das Erkrankungsspektrum zeichnet sich durch eine große genetische Heterogenität aus, wobei auch nicht genetische Ursachen bei der FSGS beobachtet werden. Die genetische Grundlage des SRNS/FSGS-Komplexes ist v. a. für ältere Kinder/Jugendliche und Erwachsene bisher noch unzureichend verstanden. Die eindeutige Abgrenzung genetischer SRNS/FSGS-Ursachen ist unerlässlich, da sich bereits heute hieraus eine Vielzahl an klinischen Implikationen ergeben. Die Identifikation unbekannter Erkrankungsallele oder Erkrankungsgene kann zudem Erkenntnisse bringen, die ein gänzlich neues Verständnis der Pathomechanismen ermöglichen. Durch umfassende genetische Untersuchungen besteht die Möglichkeit, die ungelöste genetische Basis der Rekurrenz der FSGS-Erkrankung bei bislang Varianten-negativen Patienten zu finden.

Efficacy and safety of rituximab in childhood-onset, difficult-to-treat nephrotic syndrome: A multicenter open-label trial in Korea

BACKGROUND

The anti-CD20 monoclonal antibody rituximab (RTX) has been proposed as a rescue therapy for difficult-to-treat nephrotic syndrome (NS). We conducted a clinical trial to evaluate the efficacy and safety of RTX in children with difficult-to-treat NS dependent on or resistant to steroids and calcineurin inhibitors (CNIs).

METHODS

A multicenter open-label trial was performed at 8 major pediatric nephrology centers in Korea. The investigation consisted of a randomized controlled trial for steroid- and CNI-dependent NS (DDNS; randomization into the RTX group and the control group, at a ratio of 2:1) and a single-arm study of steroid and CNI-resistant NS (DRNS). DDNS patients in the RTX group and DRNS patients received a single dose of intravenous RTX (375 mg/m of body surface area) for B-cell depletion. A second RTX dose was administered at week 2 if the first dose failed to achieve depletion of CD19(+) cells. The primary endpoint was rate of maintaining remission at 6 months after treatment for DDNS and rate of remission achievement for DRNS.

RESULTS

Sixty-one children with DDNS were enrolled while in remission and randomized to the control group (21 patients) or the RTX group (40 patients). At 6 months after treatment, the remission rates were 74.3% in the RTX group and 31.3% in the control group (P = .003). The mean duration of remission maintenance was significantly higher in the RTX group than in the control group (9.0 vs 2.9 months, P = .004). Of the 23 patients with DRNS enrolled in the single-arm study and treated with RTX, 9 (39.1%) achieved partial or complete remission within 6 months. Depletion of B cells occurred in all patients with RTX therapy. Thirty patients (50.8% of 59 patients analyzed) experienced mild and transient infusion reaction during RTX administration, and most adverse events were mild.

CONCLUSIONS

RTX administration was safe and effective in patients with difficult-to-treat NS. One or 2 doses of RTX may be sufficient to deplete B cells and achieve better control of pediatric NS.

Calcineurin Inhibitors With Reduced-Dose Steroids as First-Line Therapy for Focal Segmental Glomerulosclerosis

Introduction

High-dose corticosteroids remain the first-line therapy for focal and segmental glomerulosclerosis (FSGS), whereas calcineurin inhibitors (CNIs) are reserved for those patients resistant to corticosteroid therapy.

Methods

This is a retrospective cohort analysis in patients with primary FSGS diagnosed between 2007 and 2014. According to the administered treatment, patients were segregated into 3 groups: high-dose prednisone, first-line CNIs plus low-dose prednisone, and rescue CNIs. Cumulative corticosteroid doses were compared as well as response to therapy and long-term renal survival by Cox regression analysis.

Results

A total of 66 patients were included (39 treated with high-dose prednisone, 11 treated with first-line CNI, 16 treated with high-dose prednisone followed by rescue CNI). Cumulative doses of prednisone in the high-dose group were 9.3 g (interquartile range [IQR] = 7.5−12.5 g), compared to 2.5 g (IQR = 1.82−3.12 g) in the first-line CNI plus low-dose corticosteroid group and 13.8 g (IQR = 9.2−15.8 g) rescue CNI groups, respectively (P < 0.001). Time under corticosteroid management was also higher in the high-dose prednisone group compared to the first-line CNI group. There was a response to treatment in 76.9%, 72.7%, and 87.5% of high-dose prednisone, first-line CNI and rescue CNI groups, with complete remission in 48.7%, 36.4%, and 31.3% respectively. There was no difference in relapse incidence after treatment (48.4%, 44.4%, and 46.7%) or in 5-year renal survival (87.2%, 81.8%, and 87.5%). Baseline proteinuria, biopsy chronicity score, and response to therapy were independent predictors of renal survival.

Conclusion

An initial CNI plus low-dose corticosteroid approach in primary FSGS reduces corticosteroid exposure with a response-to-therapy rate similar to that of the currently recommended high-dose corticosteroid regimen. These findings justify a randomized trial to formally test this hypothesis.

Continuous B-cell depletion in frequently relapsing, steroid-dependent and steroid-resistant nephrotic syndrome

Background

Patients with frequently relapsing (FR), steroid-dependent (SD) and steroid-resistant (SR) nephrotic syndrome are a therapeutic challenge with limited treatment options. Here, we retrospectively analyze the efficacy and safety of rituximab-induced continuous B-cell depletion in these populations.

Methods

Patients were included if they were at least 18 years of age and had FR, SD or SR minimal change disease (MCD) or primary focal segmental glomerulosclerosis (FSGS) and were treated with a strategy of continuous B-cell depletion. Partial remission (PR) was defined as a urinary protein:creatinine ratio (UPCR) of ≤3.5 g/g and a 50% reduction in the UPCR from baseline. Complete remission (CR) was defined as a UPCR ≤0.3 g/g.

Results

We identified 20 patients with MCD (n = 13) or FSGS (n = 7) who fulfilled the inclusion criteria. All patients had either SD (n = 12), SR (n = 7) or FR (n = 1) disease. Patients received a median of nine rituximab doses [interquartile range (IQR) 7.5, 11] and were treated for a median time of 28 months (IQR 23, 41). Prednisone was weaned from a median of 60 mg daily (IQR 40, 60) at rituximab initiation to 4.5 mg daily (IQR 0, 5.5) by 12 months. All patients achieved PR. CR occurred in 11 of 13 patients with FR or SD disease, but only 1 of 7 patients with SR disease (logrank P = 0.01). Four relapses occurred, all in patients with SR disease. Three serious infections occurred over 70.3 patient-years.

Conclusion

Continuous B-cell depletion is a therapeutic option in the management of complicated nephrotic syndrome. Additional studies are needed to clarify the utility of this strategy.

Idiopathic nephrotic syndrome in children

The incidence of idiopathic nephrotic syndrome (NS) is 1·15-16·9 per 100 000 children, varying by ethnicity and region. The cause remains unknown but the pathogenesis of idiopathic NS is thought to involve immune dysregulation, systemic circulating factors, or inherited structural abnormalities of the podocyte. Genetic risk is more commonly described among children with steroid-resistant disease. The mainstay of therapy is prednisone for the vast majority of patients who are steroid responsive; however, the disease can run a frequently relapsing course, necessitating the need for alternative immunosuppressive agents. Infection and venous thromboembolism are the main complications of NS with also increased risk of acute kidney injury. Prognosis in terms of long-term kidney outcome overall is excellent for steroid-responsive disease, and steroid resistance is an important determinant of future risk of chronic or end-stage kidney disease.

Monogenic Causes of Proteinuria in Children

Glomerular disease is a common cause for proteinuria and chronic kidney disease leading to end-stage renal disease requiring dialysis or kidney transplantation in children. Nephrotic syndrome in children is diagnosed by the presence of a triad of proteinuria, hypoalbuminemia, and edema. Minimal change disease is the most common histopathological finding in children and adolescents with nephrotic syndrome. Focal segmental sclerosis is also found in children and is the most common pathological finding in patients with monogenic causes of nephrotic syndrome. Current classification system for nephrotic syndrome is based on response to steroid therapy as a majority of patients develop steroid sensitive nephrotic syndrome regardless of histopathological diagnosis or the presence of genetic mutations. Recent studies investigating the genetics of nephrotic syndrome have shed light on the pathophysiology and mechanisms of proteinuria in nephrotic syndrome. Gene mutations have been identified in several subcellular compartments of the glomerular podocyte and play a critical role in mitochondrial function, actin cytoskeleton dynamics, cell-matrix interactions, slit diaphragm, and podocyte integrity. A subset of genetic mutations are known to cause nephrotic syndrome that is responsive to immunosuppressive therapy but clinical data are limited with respect to renal prognosis and disease progression in a majority of patients. To date, more than 50 genes have been identified as causative factors in nephrotic syndrome in children and adults. As genetic testing becomes more prevalent and affordable, we expect rapid advances in our understanding of mechanisms of proteinuria and genetic diagnosis will help direct future therapy for individual patients.

Nephrotic syndrome in infants and children: pathophysiology and management

Nephrotic syndrome is defined by nephrotic-range proteinuria (≥40 mg/m²/hour or urine protein/creatinine ratio ≥200 mg/mL or 3+ protein on urine dipstick), hypoalbuminaemia (<25 g/L) and oedema. This review focuses on the classification, epidemiology, pathophysiology, management strategies and prognosis of idiopathic nephrotic syndrome of childhood, and includes a brief overview of the congenital forms.

Clinical trials in minimal change disease

Minimal change disease (MCD) is a pathological condition characterized by subtle glomerular lesions causing massive and reversible proteinuria that is usually steroid sensitive. Recurrence of symptoms of active disease following successful treatment (including proteinuria, oedema and oliguria) and steroid toxicity requires the use of other drugs to attain or maintain remission. Unresolved MCD is considered the initial step in the pathological pathway leading to focal and segmental glomerulosclerosis (FSGS). Historically, cyclophosphamide, chlorambucil, mycophenolate and calcineurin inhibitors have been utilized with success in MCD; however, the chronic nature of the disease and the toxicity of long-term use of these medications has pushed the development of new therapies. Synthetic corticotropin (adrenocorticotropic hormone) and anti-CD20 monoclonal antibodies, for example, are currently under investigation in clinical trials. In addition, these new interventions have dramatically impacted our understanding of the mechanisms of the disease. Phase II-IV clinical trials targeting new mechanisms and/or molecules are in progress. The list is long and includes drugs blocking the adaptive immune system (abatacept and anti-CD40 antibodies), as well as retinoids and the sialic acid precursor N-acetyl-D-mannosamine (ManNAc), two agents that affect the sieving properties of the glomerular basement membrane. Other drugs are being tested against FSGS and, if successful, could also be utilized against MCD. Clinical trials currently in progress should furnish a proper solution to what appears to be a solvable problem.

Efficacy and safety of immunosuppressive medications for steroid-resistant nephrotic syndrome in children: a systematic review and network meta-analysis

Background

Conventional meta-analyses and randomized controlled trials have shown inconsistent results regarding the efficacy of immunosuppressants for pediatric steroid-resistant nephrotic syndrome (SRNS).

Objective

To conduct a network meta-analysis aimed at evaluating the efficacy and safety of available immunosuppressive agents in pediatric patients with SRNS.

Study methods

MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE were searched on January 2017. Data from randomized controlled trials (RCTs) were included. The main outcomes analyzed were efficacy [number/portion with complete remission (CR), number/portion with partial remission (PR), and total number/portion in remission (TR)] and safety [adverse secondary event (ASE) rates].

Results

A meta-analysis of 18 RCTs showed that tacrolimus was more efficacious for achieving CR than intravenous (i.v.) cyclophosphamide, mycophenolate mofetil (MMF), oral cyclophosphamide, leflunomide, chlorambucil, azathioprine, and plaebo/nontreatment (P/NT), and more efficacious than i.v. cyclophosphamide, oral cyclophosphamide, and P/NT in terms of TR outcomes. Cyclosporin was associated with a greater CR rate than i.v. cyclophosphamide, MMF, oral cyclophosphamide, chlorambucil, azathioprine, or P/NT, and associated with a greater TR rate than i.v. cyclophosphamide, oral cyclophosphamide, or P/NT. MMF was found to be more efficacious than i.v. cyclophosphamide and oral cyclophosphamide in terms of TR.

Conclusions

Tacrolimus and cyclosporine may be preferred initial treatments for children with SRNS. MMF may be another option for this patient population. Further studies of the efficacy and safety of these three drugs in children with SRNS should be pursued.

Cyclosporine-based immunosuppressive therapy for patients with steroid-resistant focal segmental glomerulosclerosis: a meta-analysis

OBJECTIVE

Focal segmental glomerulosclerosis (FSGS) is a leading cause of end-stage kidney disease that requires immunosuppressive treatment as therapy. Few studies have been specifically designed to assess the efficacy of cyclosporine (CSA) in patients with steroid-resistant FSGS. This study investigated the efficacy of CSA-based therapy in steroid-resistant FSGS.

METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched through April 30, 2014 using the keywords "cyclosporine", "steroid-resistant", "focal segmental glomerulosclerosis", and "FSGS". Studies with an adult and children with steroid-resistant primary FSGS treated with CSA-based therapy with or without steroid use were included. Complete, partial, and overall remission were the primary outcomes. Change in proteinuria, serum creatinine, and estimated glomerular filtration rate (eGFR) following treatment were secondary outcomes.

RESULTS

Seven randomized controlled trials with a total of 373 patients were included. Five studies were included in the meta-analysis to assess complete, partial, and overall remission of FSGS. Compared with other treatments, CSA-based therapy resulted in a significantly greater partial remission rate (p = .018), but complete (p = .226) or overall remission rate (p = .050). CSA-based therapy also resulted in similar change in proteinuria (p = .084), serum creatinine (p = .772), and eGFR (p = .155) compared with other therapy. Study limitations included small sample size and heterogeneity in age and comparative treatments across the studies.

CONCLUSIONS

Cyclosporin-based treatments provided a significantly better partial remission rate as compared with other therapies.

Combined cyclosporine and prednisolone therapy using cyclosporine blood concentration monitoring for adult patients with new-onset minimal change nephrotic syndrome: a single-center pilot randomized trial

BACKGROUND

Minimal change nephrotic syndrome (MCNS) responds well to steroids, but some patients show frequent relapses. Long-term steroid administration leads to various adverse effects. We previously reported the effectiveness in refractory nephrosis patients of administrating microemulsified CyA (ME-CyA) once before meals and setting the target value of the CyA blood concentration at 2 h after ME-CyA administration (C2) to 600-1200 ng/ml. On this trial we evaluate the effectiveness and safety of ME-CyA for suppressing relapse of adult new-onset MCNS patients using C2 monitoring.

METHODS

Adult new-onset MCNS patients were randomly allocated to a ME-CyA + prednisolone group ("CyA + PSL") (n = 11) and a PSL-alone group ("PSL-alone") (n = 10). The drug administration period was 18 months followed by an observation period of 12 months.

RESULTS

The duration of remission tended to be longer in CyA + PSL with C2 >600 ng/ml than in PSL-alone (P = 0.112). The relapse rate up to 18 months was significantly lower in CyA + PSL with C2 >600 ng/ml than in PSL-alone (P = 0.02). C2 was significantly higher in the patients with no relapse at 18 months than that in the patients with relapse (P = 0.048). In CyA + PSL, the total dose of PSL was significantly reduced compared with PSL-alone (P = 0.002). Cosmetic adverse effects tended to be fewer in CyA + PSL.

CONCLUSIONS

The combination treatment regimen of ME-CyA and PSL with C2 >600 ng/ml has potential to be an important treatment option for adult new-onset MCNS patients. However, after ME-CyA dosage reduction and discontinuation, the relapse rate increased. It is thus necessary to establish a better dose-reduction method.

Safety and Efficacy of Combination ACTHar Gel and Tacrolimus in Treatment-Resistant Focal Segmental Glomerulosclerosis and Membranous Glomerulopathy

Introduction

H.P. ACTHar gel is a preparation of melanocortin peptides that has been used to treat resistant forms of nephrotic syndrome. To determine whether combination therapy with ACTHar gel and tacrolimus reduces proteinuria and stabilizes renal function, we conducted a prospective, open-label trial in patients with treatment-resistant membranous glomerulopathy (MGN) and focal segmental glomerulosclerosis (FSGS).

Methods

Nine patients with treatment-resistant MGN and 13 with treatment-resistant FSGS received subcutaneous ACTHar gel for 6 months. Patients with no response or a partial response to ACTHar gel alone received an additional 6 months of therapy with combination ACTHar gel and oral tacrolimus. The study endpoint was the percentage of patients achieving a complete or partial remission after 6 months of combination therapy.

Results

Among patients with MGN, treatment with ACTHar gel alone achieved a partial remission in 44% and no response in 56% of patients. No patient achieved a complete response with ACTHar gel therapy alone. An additional 6 months of combination therapy with ACTHar gel and tacrolimus resulted in partial and complete response rates of 25% and 75%, respectively. Among patients with FSGS, ACTHar gel therapy alone resulted in complete and partial response rate of 7.7% and 62.0%. Combination therapy increased complete response rates to 17% and partial responses to 66%. Proteinuria (urinary protein-to-creatinine ratio) was significantly reduced in both patients with MGN and those with FSGS after 6 months of ACTHar gel alone and was further reduced among the patients with MGN with the addition of tacrolimus. There were no significant changes in estimated glomerular filtration rate during the treatment phase or long-term follow-up.

Discussion

Combination therapy with ACTHar gel and tacrolimus was well tolerated by patients with treatment-resistant MGN and FSGS and significantly reduced proteinuria and improved clinical response rates compared with ACTHar gel alone.

Optimal management of primary focal segmental glomerulosclerosis in adults

Focal segmental glomerulosclerosis (FSGS) is a frequent glomerular kidney disease that is revealed by proteinuria or even nephrotic syndrome. A diagnosis can be established from a kidney biopsy that shows focal and segmental glomerulosclerosis. This histopathological lesion may be caused by a primary podocyte injury (idiopathic FSGS) but is also associated with other pathologies (secondary FSGS). The first-line treatment for idiopathic FSGS with nephrotic syndrome is a prolonged course of corticosteroids. However, steroid resistance or steroid dependence is frequent, and despite intensified immunosuppressive treatment, FSGS can lead to end-stage renal failure. In addition, in some cases, FSGS can recur on a graft after kidney transplantation: an unidentified circulating factor may be implicated. Understanding of its physiopathology is unclear, and it remains an important challenge for the scientific community to identify a specific diagnostic biomarker and to develop specific therapeutics. This study reviews the treatment of primary FSGS and the recurrence of FSGS after kidney transplantation in adults.

Recent Treatment Advances and New Trials in Adult Nephrotic Syndrome

The etiology of nephrotic syndrome is complex and ranges from primary glomerulonephritis to secondary forms. Patients with nephrotic syndrome often need immunosuppressive treatment with its side effects and may progress to end stage renal disease. This review focuses on recent advances in the treatment of primary causes of nephrotic syndrome (idiopathic membranous nephropathy (iMN), minimal change disease (MCD), and focal segmental glomerulosclerosis (FSGS)) since the publication of the KDIGO guidelines in 2012. Current treatment recommendations are mostly based on randomized controlled trials (RCTs) in children, small RCTs, or case series in adults. Recently, only a few new RCTs have been published, such as the Gemritux trial evaluating rituximab treatment versus supportive antiproteinuric and antihypertensive therapy in iMN. Many RCTs are ongoing for iMN, MCD, and FSGS that will provide further information on the effectiveness of different treatment options for the causative disease. In addition to reviewing recent clinical studies, we provide insight into potential new targets for the treatment of nephrotic syndrome from recent basic science publications.

A Phase 2, Double-Blind, Placebo-Controlled, Randomized Study of Fresolimumab in Patients With Steroid-Resistant Primary Focal Segmental Glomerulosclerosis

Introduction

Steroid-resistant focal segmental glomerulosclerosis (SR-FSGS) is a common glomerulopathy associated with nephrotic range proteinuria. Treatment goals are reduction in proteinuria, which can delay end-stage renal disease.

Methods

Patients with SR-FSGS were enrolled in a randomized, double-blind placebo-controlled trial of fresolimumab, a monoclonal anti−transforming growth factor−β antibody, at 1 mg/kg or 4 mg/kg for 112 days, followed double-blind for 252 days (NCT01665391). The primary efficacy endpoint was the percentage of patients achieving partial (50% reduction) or complete (< 300 mg/g Cr) remission of proteinuria.

Results

Of 36 enrolled patients, 10, 14, and 12 patients received placebo, fresolimumab 1 mg/kg, and fresolimumab 4 mg/kg, respectively. The baseline estimated glomerular filtration rate (eGFR) and urinary protein/creatinine ratio were 63 ml/min/1.73 m² and 6190 mg/g, respectively. The study was closed before reaching its target of 88 randomized patients. None of the prespecified efficacy endpoints for proteinuria reduction were achieved; however, at day 112, the mean percent change in urinary protein/creatinine ratio (a secondary efficacy endpoint) was –18.5% (P = 0.008), +10.5% (P = 0.52), and +9.0% (P = 0.91) in patients treated with fresolimumab 1 mg/kg, fresolimumab 4 mg/kg, and placebo, respectively. There was a nonsignificant trend toward greater estimated glomerular filtration rate decline in the placebo group compared to either of the fresolimumab-treated arms up to day 252.

Discussion

The study was underpowered and did not meet the primary or secondary endpoints. However, fresolimumab was well tolerated and is appropriate for continued evaluation in larger studies with adequate power.

Mycophenolate mofetil is inferior to tacrolimus in sustaining remission in children with idiopathic steroid-resistant nephrotic syndrome

Studies of nephrotic syndrome show that substitution of calcineurin inhibitors by mycophenolate mofetil (MMF) enables sustained remission and corticosteroid sparing and avoids therapy associated adverse effects. However, controlled studies in patients with steroid resistance are lacking. Here we examined the effect of switching from therapy with tacrolimus to MMF on disease course in an open-label, one-to-one randomized, controlled trial on children (one to 18 years old), recently diagnosed with steroid-resistant nephrotic syndrome, at a referral center in India. Following six months of therapy with tacrolimus, patients with complete or partial remission were randomly assigned such that 29 received MMF while 31 received tacrolimus along with tapering prednisolone on alternate days for 12 months. On intention-to-treat analyses, the proportion of patients with a favorable outcome (sustained remission, infrequent relapses) at one year was significantly lower (44.8%) in the MMF group than in the tacrolimus group (90.3%). The incidence of relapses was significantly higher for patients treated with MMF than tacrolimus (mean difference: 1.05 relapses per person-year). While there was no difference in the proportion of patients with sustained remission, the risk of recurrence of steroid resistance was significantly higher for patients receiving MMF compared to tacrolimus (mean difference: 20.7%). Compared to tacrolimus, patients receiving MMF had a significantly (71%) lower likelihood of a favorable outcome and significantly increased risk of treatment failure (frequent relapses, steroid resistance). Thus, replacing tacrolimus with MMF after six months of tacrolimus therapy for steroid-resistant nephrotic syndrome in children is associated with significant risk of frequent relapses or recurrence of resistance. These findings have implications for guiding the duration of therapy with tacrolimus for steroid-resistant nephrotic syndrome.

Calcineurin Inhibitors in the Treatment of Primary Focal Segmental Glomerulosclerosis: A Systematic Review and Meta-analysis of the Literature

Purpose of review:

Primary focal segmental glomerulosclerosis (FSGS) is the most common cause of nephrotic syndrome in adults. Glucocorticoids have been evaluated in the treatment of primary FSGS in numerous retrospective studies. Evidence suggesting a role for including calcineurin inhibitors (CNIs) in early therapy remains limited. The aim of this study was to systematically review the literature examining the efficacy of CNIs in the treatment of primary FSGS both as first-line therapy and as an adjunctive agent in steroid-resistant patients, with respect to remission in proteinuria and renal survival.

Sources of information:

PubMed and EMBASE were searched from inception to August 2014 for prospective controlled trials, and case-control and cohort studies.

Findings:

After systematically applying our inclusion criteria, a total of 152 titles and abstracts were identified. Six randomized controlled trials and 2 cohort studies were reviewed. Three randomized controlled trials compared CNIs with placebo or supportive therapy. The pooled relative “risk” of proteinuria remission associated with cyclosporine was 7.0 (95% confidence interval, 2.9-16.8) compared with placebo/supportive therapy. There was very low heterogeneity among these studies with an I-squared of 0%. Three studies compared CNIs with another immunosuppressive agent. All prospective trials were conducted in patients with primary FSGS deemed steroid-resistant.

Limitations:

The relatively small number of included studies and their heterogeneity with respect to treatment protocols, and possible publication bias, limit conclusions drawn from this systematic review.

Implications:

The efficacy of CNIs has been evaluated in steroid-resistant primary FSGS patients. There is no evidence supporting their role as first-line therapy. Further studies are needed to determine this role.

How randomised trials have improved the care of children with kidney disease

Randomised controlled trials (RCTs) provide the most reliable way to evaluate the benefits and harms of interventions. Participants are divided into groups using methods that balance the characteristics (both known and unknown) of the participants between treatment groups; thus, differences in outcomes are due to the interventions administered. From Cochrane Kidney and Transplant's Specialised Register, a comprehensive registry of trials in kidney disease, we identified 482 trials involving children. The vast majority concerned urinary tract infection (UTI; 134) and nephrotic syndrome (136). Most were small, with a median enrolment of 46 children, with only 26 trials enrolling 200 or more participants, and of these, 18 involved children with UTI. We discuss a number of important advances in the care of children with UTI with or without vesico-ureteric reflux, nephrotic syndrome, chronic kidney disease (CKD) and kidney transplantation that have been driven largely by trials in these conditions.

Interventions for idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

The majority of children who present with their first episode of nephrotic syndrome achieve remission with corticosteroid therapy. Children who fail to respond may be treated with immunosuppressive agents including calcineurin inhibitors (cyclosporin or tacrolimus) and with non-immunosuppressive agents such as angiotensin-converting enzyme inhibitors (ACEi). Optimal combinations of these agents with the least toxicity remain to be determined. This is an update of a review first published in 2004 and updated in 2006 and 2010.

OBJECTIVES

To evaluate the benefits and harms of different interventions used in children with idiopathic nephrotic syndrome, who do not achieve remission following four weeks or more of daily corticosteroid therapy.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register (up to 2 March 2016) through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

RCTs and quasi-RCTs were included if they compared different immunosuppressive agents or non-immunosuppressive agents with placebo, prednisone or other agent given orally or parenterally in children aged three months to 18 years with SRNS.

DATA COLLECTION AND ANALYSIS

Two authors independently searched the literature, determined study eligibility, assessed risk of bias and extracted data. For dichotomous outcomes, results were expressed as risk ratios (RR) and 95% confidence intervals (CI). Data were pooled using the random effects model.

MAIN RESULTS

Nineteen RCTs (820 children enrolled; 773 evaluated) were included. Most studies were small. Eleven studies were at low risk of bias for allocation concealment and only four studies were at low risk of performance bias. Fifteen, eight and 10 studies were at low risk of detection bias, attrition bias and reporting bias respectively. Cyclosporin when compared with placebo or no treatment significantly increased the number of children who achieved complete remission. However this was based on only eight children who achieved remission with cyclosporin compared with no children who achieved remission with placebo/no treatment in three small studies (49 children: RR 7.66, 95% CI 1.06 to 55.34). Calcineurin inhibitors significantly increased the number with complete or partial remission compared with IV cyclophosphamide (2 studies, 156 children: RR 1.98, 95% CI 1.25 to 3.13; I² = 20%). There was no significant differences in the number who achieved complete remission between tacrolimus versus cyclosporin (1 study, 41 children: RR 0.86, 95% CI 0.44 to 1.66), cyclosporin versus mycophenolate mofetil plus dexamethasone (1 study, 138 children: RR 2.14, 95% CI 0.87 to 5.24), oral cyclophosphamide with prednisone versus prednisone alone (2 studies, 91 children: RR 1.06, 95% CI 0.61 to 1.87), IV versus oral cyclophosphamide (1 study, 11 children: RR 3.13, 95% CI 0.81 to 12.06), IV cyclophosphamide versus oral cyclophosphamide plus IV dexamethasone (1 study, 49 children: RR 1.13, 95% CI 0.65 to 1.96), and azathioprine with prednisone versus prednisone alone (1 study, 31 children: RR 0.94, 95% CI 0.15 to 5.84). One study found no significant differences between three agents (cyclophosphamide, mycophenolate mofetil, leflunomide) used in combination with tacrolimus and prednisone. One study found no significant difference in the percentage reduction in proteinuria (31 children: -12; 95% CI -73 to 110) between rituximab with cyclosporin/prednisolone and cyclosporin/prednisolone alone. Two studies reported ACEi significantly reduced proteinuria.

AUTHORS' CONCLUSIONS

To date RCTs have demonstrated that calcineurin inhibitors increase the likelihood of complete or partial remission compared with placebo/no treatment or cyclophosphamide. For other regimens assessed, it remains uncertain whether the interventions alter outcomes because the certainty of the evidence is low. Further adequately powered, well designed RCTs are needed to evaluate other regimens for children with idiopathic SRNS. Since SRNS represents a spectrum of diseases, future studies should enrol children from better defined groups of patients with SRNS.

Krüppel-Like Factor 15 Mediates Glucocorticoid-Induced Restoration of Podocyte Differentiation Markers

Podocyte injury is the inciting event in primary glomerulopathies, such as minimal change disease and primary FSGS, and glucocorticoids remain the initial and often, the primary treatment of choice for these glomerulopathies. Because inflammation is not readily apparent in these diseases, understanding the direct effects of glucocorticoids on the podocyte, independent of the immunomodulatory effects, may lead to the identification of targets downstream of glucocorticoids that minimize toxicity without compromising efficacy. Several studies showed that treatment with glucocorticoids restores podocyte differentiation markers and normal ultrastructure and improves cell survival in murine podocytes. We previously determined that Krüppel-like factor 15 (KLF15), a kidney-enriched zinc finger transcription factor, is required for restoring podocyte differentiation markers in mice and human podocytes under cell stress. Here, we show that in vitro treatment with dexamethasone induced a rapid increase of KLF15 expression in human and murine podocytes and enhanced the affinity of glucocorticoid receptor binding to the promoter region of KLF15 In three independent proteinuric murine models, podocyte-specific loss of Klf15 abrogated dexamethasone-induced podocyte recovery. Furthermore, knockdown of KLF15 reduced cell survival and destabilized the actin cytoskeleton in differentiated human podocytes. Conversely, overexpression of KLF15 stabilized the actin cytoskeleton under cell stress in human podocytes. Finally, the level of KLF15 expression in the podocytes and glomeruli from human biopsy specimens correlated with glucocorticoid responsiveness in 35 patients with minimal change disease or primary FSGS. Thus, these studies identify the critical role of KLF15 in mediating the salutary effects of glucocorticoids in the podocyte.

Pharmacokinetics of mycophenolic acid in children with clinically stable idiopathic nephrotic syndrome receiving cyclosporine

BACKGROUND

The suitable dosage regime of mycophenolate mofetil (MMF) based on the pharmacokinetics of mycophenoric acid (MPA) for pediatric patients with idiopathic nephrotic syndrome (INS) is controversial. The pharmacokinetics of MPA is influenced by renal function, serum albumin concentration, and concomitant medications, especially calcineurin inhibitors. This study analyzed the pharmacokinetics of MPA in clinically stable children with INS receiving cyclosporine (CyA).

METHODS

This retrospective study enrolled children with INS receiving MMF (Cellcept^®) (30-40 mg/kg/day in two divided doses) combined with CyA (Neoral^®) without relapse and renal dysfunction. Pharmacokinetic parameters, including the area under the concentration-time curve (AUC) calculated by the trapezoid method, were calculated from seven serial blood samples.

RESULTS

Thirty-two patients (22 males) of median age 11.0 years were included; 32 pharmacokinetic studies were performed. The median MMF dose was 16.2 mg/kg/time or 470.4 mg/m²/time. The median AUC0-12 was 44.3 ng h/mL. AUC0-12 of all patients showed excellent correlations with C2 (r ²  = 0.6405, P < 0.0001), resulting in a regression formula of AUC0-12 = 21.971 + 2.6059 C2. Comparisons of dose/body weight-normalized AUC0-12 values among age groups showed a lower value in the youngest group (≤5 years).

CONCLUSION

In children with clinically stable INS receiving CyA, C2 monitoring was the most useful single parameter for estimating MPA pharmacokinetics. Younger children required higher MMF doses.

Long-term remission of HSCT-related NS after a second allogenic stem cell transplant

BACKGROUND

Hematopoietic stem cell transplantation (HSCT)-related nephrotic syndrome (NS) is a rare event and has been described as a clinical form of chronic graft-versus-host disease (GVHD). Although immunological mechanisms are thought to play important roles in NS after HSCT, the exact mechanisms have not been clarified.

CASE-DIAGNOSIS/TREATMENT

We report a 4-year-old boy with acute lymphoblastic leukemia (ALL) who developed NS during the tapering of immunosuppressants 5 months after an allogeneic HSCT (allo-HSCT). A renal biopsy was performed, and light and electron microscopy revealed minimal change disease (MCD). Although the response to treatment with steroids and tacrolimus was favorable, the child experienced two relapses of NS within the first 9 months after the initial response. A second allo-HSCT was performed to treat the relapse of ALL. After the second allo-HSCT, the remission of NS was maintained without recurrence for 5 years, even after the cessation of immunosuppressants.

CONCLUSIONS

Our patient who had ALL and developed NS after his first allo-HSCT, maintained remission from NS after a second allo-HSCT. This suggests that the immune cells from the first donor origin were associated with the pathogenesis of NS.

Long-term outcome of idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

Several recent studies have shown improved short-term outcome of steroid-resistant nephrotic syndrome (SRNS) in children; however, only a few studies have evaluated the long-term outcome. The aims of our study were to obtain detailed data and analyze the long-term outcome of children with SRNS.

METHODS

Sixty-nine children with idiopathic SRNS were enrolled and divided into two groups based on initial histopathological patterns: focal segmental glomerulosclerosis (FSGS) and minimal change (MC)/diffuse mesangial proliferation (DMP). The effects of initial treatment with the immunosuppressant of choice (cyclosporine or cyclophosphamide) on renal survival, remission, and incidence of complications were analyzed in both groups (4 subgroups).

RESULTS

The renal survival rate was significantly different among the four different subgroups based on different combinations of initial histopathological pattern (FSGS vs. MC/DMP) and initial immunosuppressant used for treating SRNS (cyclosporine vs. cyclophosphamide) (P = 0.013), with renal survival in the FSGS (cyclophosphamide) subgroup being especially low (54.6 %). Disease- and/or treatment-associated complications were relatively low; however, hypertension at last examination was observed in a considerable number of patients (31.9 %).

CONCLUSIONS

Our results suggest that a recently developed therapeutic regimen with cyclosporine considerably improves both the initial remission rate and the long-term renal survival rate of children with idiopathic SRNS.