Mycophenolate mofetil versus cyclosporine for remission maintenance in nephrotic syndrome

Immunosuppressive agents for frequently relapsing/steroid-dependent nephrotic syndrome in children: a systematic review and network meta-analysis

Aim

This study aimed to systematically compare the efficacy of various immunosuppressive agents in treating pediatric frequently relapsing or steroid-dependent nephrotic syndrome (FRSDNS).

Methods

We conducted systematic searches of PubMed, Embase, the Cochrane Library, and the Web of Science up to May 23, 2023. Outcome measures included relapses within 1 year, mean cumulative exposure to corticosteroids, patients with treatment failure at 1 year, relapse-free survival during 1 year, and adverse events. The quality of the included studies was evaluated using the modified Jadad scale, the Methodological Index for Non-Randomized Studies (MINORS), and the modified Newcastle-Ottawa Scale (NOS).

Results

Rituximab was found to be the most likely (92.44%) to be associated with the fewest relapses within 1 year and was also most likely (99.99%) to result in the lowest mean cumulative exposure to corticosteroids. Rituximab had the highest likelihood (45.98%) of being associated with the smallest number of patients experiencing treatment failure at 1 year. CsA was most likely (57.93%) to achieve the highest relapse-free survival during 1 year, followed by tacrolimus (26.47%) and rituximab (30.48%). Rituximab showed no association with serious side effects and had comparable adverse effects to ofatumumab and tacrolimus.

Conclusion

Rituximab may be the most favorable immunosuppressive agent for treating pediatric FRSDNS. Nephrologists should consider this drug, along with their clinical experience, patient characteristics, and cost considerations, when choosing a treatment approach.

Therapeutic drug monitoring in childhood idiopathic nephrotic syndrome: a state of the art review

Immunosuppressants are commonly used as steroid-sparing agents in childhood idiopathic nephrotic syndrome (NS) to induce and sustain remissions. These drugs have narrow therapeutic indices with high inter- and intra-patient variability. Therapeutic drug monitoring (TDM) would therefore be essential to guide the prescription. Multiple factors in NS contribute to additional variability in drug concentrations, especially during relapses. In this article, we review the currently available evidence of TDM in NS and suggest a practical approach for clinicians' reference.

Childhood nephrotic syndrome

Idiopathic nephrotic syndrome is the most common glomerular disease in children. Corticosteroids are the cornerstone of its treatment, and steroid response is the main prognostic factor. Most children respond to a cycle of oral steroids, and are defined as having steroid-sensitive nephrotic syndrome. Among the children who do not respond, defined as having steroid-resistant nephrotic syndrome, most respond to second-line immunosuppression, mainly with calcineurin inhibitors, and children in whom a response is not observed are described as multidrug resistant. The pathophysiology of nephrotic syndrome remains elusive. In cases of immune-mediated origin, dysregulation of immune cells and production of circulating factors that damage the glomerular filtration barrier have been described. Conversely, up to a third of cases of steroid-resistant nephrotic syndrome have a monogenic origin. Multidrug resistant nephrotic syndrome often leads to kidney failure and can cause relapse after kidney transplant. Although steroid-sensitive nephrotic syndrome does not affect renal function, most children with steroid-sensitive nephrotic syndrome have a relapsing course that requires repeated steroid cycles with significant side-effects. To minimise morbidity, some patients require steroid-sparing immunosuppressive agents, including levamisole, mycophenolate mofetil, calcineurin inhibitors, anti-CD20 monoclonal antibodies, and cyclophosphamide. Close monitoring and preventive measures are warranted at onset and during relapse to prevent acute complications (eg, hypovolaemia, acute kidney injury, infections, and thrombosis), whereas long-term management requires minimising treatment-related side-effects. A subset of patients have active disease into adulthood.

Therapeutic trials in difficult to treat steroid sensitive nephrotic syndrome: challenges and future directions

Steroid sensitive nephrotic syndrome is a common condition in pediatric nephrology, and most children have excellent outcomes. Yet, 50% of children will require steroid-sparing agents due to frequently relapsing disease and may suffer consequences from steroid dependence or use of steroid-sparing agents. Several steroid-sparing therapeutic agents are available with few high quality randomized controlled trials to compare efficacy leading to reliance on observational data for clinical guidance. Reported trials focus on short-term outcomes such as time to first relapse, relapse rates up to 1-2 years of follow-up, and few have studied long-term remission. Trial designs often do not consider inter-individual variability, and differing response to treatments may occur due to heterogeneity in pathogenic mechanisms, and genetic and environmental influences. Strategies are proposed to improve the quantity and quality of trials in steroid sensitive nephrotic syndrome with integration of biomarkers, novel trial designs, and standardized outcomes, especially for long-term remission. Collaborative efforts among international trial networks will help move us toward a shared goal of finding a cure for children with nephrotic syndrome.

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

Idiopathic nephrotic syndrome is the most frequent pediatric glomerular disease, affecting from 1.15 to 16.9 per 100,000 children per year globally. It is characterized by massive proteinuria, hypoalbuminemia, and/or concomitant edema. Approximately 85-90% of patients attain complete remission of proteinuria within 4-6 weeks of treatment with glucocorticoids, and therefore, have steroid-sensitive nephrotic syndrome (SSNS). Among those patients who are steroid sensitive, 70-80% will have at least one relapse during follow-up, and up to 50% of these patients will experience frequent relapses or become dependent on glucocorticoids to maintain remission. The dose and duration of steroid treatment to prolong time between relapses remains a subject of much debate, and patients continue to experience a high prevalence of steroid-related morbidity. Various steroid-sparing immunosuppressive drugs have been used in clinical practice; however, there is marked practice variation in the selection of these drugs and timing of their introduction during the course of the disease. Therefore, international evidence-based clinical practice recommendations (CPRs) are needed to guide clinical practice and reduce practice variation. The International Pediatric Nephrology Association (IPNA) convened a team of experts including pediatric nephrologists, an adult nephrologist, and a patient representative to develop comprehensive CPRs on the diagnosis and management of SSNS in children. After performing a systematic literature review on 12 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, recommendations were formulated and formally graded at several virtual consensus meetings. New definitions for treatment outcomes to help guide change of therapy and recommendations for important research questions are given.

Second and Third Generational Advances in Therapies of the Immune-Mediated Kidney Diseases in Children and Adolescents

Therapy of immune-mediated kidney diseases has evolved during recent decades from the non-specific use of corticosteroids and antiproliferative agents (like cyclophosphamide or azathioprine), towards the use of more specific drugs with measurable pharmacokinetics, like calcineurin inhibitors (cyclosporine A and tacrolimus) and mycophenolate mofetil, to the treatment with biologic drugs targeting detailed specific receptors, like rituximab, eculizumab or abatacept. Moreover, the data coming from a molecular science revealed that several drugs, which have been previously used exclusively to modify the upregulated adaptive immune system, may also exert a local effect on the kidney microstructure and ameliorate the functional instability of podocytes, reducing the leak of protein into the urinary space. The innate immune system also became a target of new therapies, as its specific role in different kidney diseases has been de novo defined. Current therapy of several immune kidney diseases may now be personalized, based on the detailed diagnostic procedures, including molecular tests. However, in most cases there is still a space for standard therapies based on variable protocols including usage of steroids with the steroid-sparing agents. They are used as a first-line treatment, while modern biologic agents are selected as further steps in cases of lack of the efficacy or toxicity of the basic therapies. In several clinical settings, the biologic drugs are effective as the add-on therapy.

Update on the treatment of steroid-sensitive nephrotic syndrome

Steroid-sensitive nephrotic syndrome (SSNS) is a rare condition that develops primarily in preadolescent children after the age of 1 year. Since the 1950s, oral corticosteroids have been the mainstay of treatment of all children presenting with nephrotic syndrome, with most patients responding within 4 weeks to an oral course of prednisone (PDN). However, corticosteroids have important side effects and 60-80 % of patients relapse, developing frequently relapsing or steroid-dependent forms. For these reasons, many patients require second-line steroid-sparing immunosuppressive medications that have considerably improved relapse-free survival, while avoiding many PDN-related toxicities. Since most patients will eventually heal from their disease with a normal kidney function, the morbidity of SSNS is primarily related to side effects of drugs that are used to maintain prolonged remission. Therefore, treatment is essentially based on balancing the use of different drugs to achieve permanent remission with the lowest cumulative number of side effects. Treatment choice is based on the severity of SSNS, on patient age, and on drug tolerability. This review provides an update of currently available therapeutic strategies for SSNS.

Nephrotic Syndrome

Nephrotic syndrome (NS) encompasses a variety of disease processes leading to heavy proteinuria and edema. Minimal change disease (MCD) remains the most common primary cause of NS, as well as the most responsive to pharmacologic treatment with often minimal to no chronic kidney disease. Other causes of NS include focal segmental glomerulosclerosis, which follows MCD, and secondary causes, including extrarenal or systemic diseases, infections, and drugs. Although initial diagnosis relies on clinical findings as well as urine and blood chemistries, renal biopsy and genetic testing are important diagnostic tools, especially when considering non-MCD NS. Moreover, biomarkers in urine and serum have become important areas for research in this disease. NS progression and prognosis are variable and depend on etiology, with corticosteroids being the mainstay of treatment. Other alternative therapies found to be successful in inducing and maintaining remission include calcineurin inhibitors and rituximab. Disease course can range from recurrent disease relapse with or without acute kidney injury to end-stage renal disease in some cases. Given the complex pathogenesis of NS, which remains incompletely understood, complications are numerous and diverse and include infections, electrolyte abnormalities, acute kidney injury, and thrombosis. Pediatricians must be aware of the presentation, complications, and overall long-term implications of NS and its treatment.

Mycophenolate Mofetil in the Treatment of Steroid-Dependent or Frequently Relapsing Nephrotic Syndrome in Children: A Meta-Analysis

Objectives: This meta-analysis aims to evaluate the efficacy and safety of the mycophenolate mofetil (MMF) in the treatment of steroid-dependent nephrotic syndrome (SDNS) or frequently relapsing nephrotic syndrome (FRNS) in children. Methods: We searched for the studies especially the randomized controlled trials in PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure, and Wan Fang database. The data were analyzed by Review Manager 5.3 software. We used the GRADE pro-Guideline Development Tool online software to evaluate the quality of evidence. Results: Finally, we identified 620 studies, of which we included five randomized controlled trials and one prospective cohort study with 447 children. The results showed the following: (1) the relapse-free survival rate within 1 year-the MMF group was superior to the levamisole group [ratio difference (RD) = 0.13, 95% CI (0.02, 0.24), P = 0.02] but not to the calcineurin inhibitors (CNIs) group [RD = -0.27, 95%CI (-0.40, -0.14), P < 0.0001]; (2) the number of relapses within 1 year-the MMF group was less than that in the CNIs and levamisole group [mean difference (MD) = -0.26, 95%CI (-0.45, -0.08), P = 0.005]; (3) the cumulative prednisone dosage-the MMF group was lower than that in the control group [standardized mean difference (SMD) = -0.32, 95%CI (-0.53, -0.11), P = 0.003]; (4) incidence of adverse reactions-there was no significant difference between the MMF group and the control group [RD = 0.02, 95%CI (-0.04, 0.09), P = 0.46]. Conclusion: The therapy of mycophenolate mofetil in the treatment of SDNS or FRNS in children has a certain advantage in reducing the number of relapses and cumulative prednisone dosage within 1 year when compared with the CNIs and levamisole. However, due to the limited quantity and quality of the included studies, the conclusions above need to be confirmed by more high-quality randomized controlled trials.

CD80 Insights as Therapeutic Target in the Current and Future Treatment Options of Frequent-Relapse Minimal Change Disease

Minimal change disease (MCD) is the most common cause of idiopathic nephrotic syndrome in children, and it is well known for its multifactorial causes which are the manifestation of the disease. Proteinuria is an early consequence of podocyte injury and a typical sign of kidney disease. Steroid-sensitive patients react well with glucocorticoids, but there is a high chance of multiple relapses. CD80, also known as B7-1, is generally expressed on antigen-presenting cells (APCs) in steroid-sensitive MCD patients. Various glomerular disease models associated with proteinuria demonstrated that the detection of CD80 with the increase of urinary CD80 was strongly associated closely with frequent-relapse MCD patients. The role of CD80 in MCD became controversial because one contradicts finding. This review covers the treatment alternatives for MCD with the insight of CD80 as a potential therapeutic target. The promising effectiveness of CD20 (rituximab) antibody and CD80 inhibitor (abatacept) encourages further investigation of CD80 as a therapeutic target in frequent-relapse MCD patients. Therapeutic-based antibody towards CD80 (galiximab) had never been investigated in MCD or any kidney-related disease; hence, the role of CD80 is still undetermined. A new therapeutic approach towards MCD is essential to provide broader effective treatment options besides the general immunosuppressive agents with gruesome adverse effects.

Practice variations in the management of childhood nephrotic syndrome in the Netherlands

Nephrotic syndrome in childhood is a common entity in the field of pediatric nephrology. The optimal treatment of children with nephrotic syndrome is often debated. Previously conducted studies have shown significant variability in nephrotic syndrome management, especially in the choice of steroid-sparing drugs. In the Netherlands, a practice guideline on the management of childhood nephrotic syndrome has been available since 2010. The aim of this study was to identify practice variations and opportunities to improve clinical practice of childhood nephrotic syndrome in the Netherlands. A digital structured survey among Dutch pediatricians and pediatric nephrologists was performed, including questions regarding the initial treatment, relapse treatment, kidney biopsy, additional immunosuppressive treatment, and supportive care. Among the 51 responses, uniformity was seen in the management of a first presentation and first relapse. Wide variation was found in the tapering of steroids after alternate day dosing. Most pediatricians and pediatric nephrologists (83%) would perform a kidney biopsy in case of steroid-resistant nephrotic syndrome, whereas for frequent relapsing and steroid-dependent nephrotic syndrome this was 22% and 41%, respectively. Variation was reported in the steroid-sparing treatment. Finally, significant differences were present in the supportive treatment of nephrotic syndrome.Conclusion: Substantial variation was present in the management of nephrotic syndrome in the Netherlands. Differences were identified in steroid tapering, use of steroid coverage during stress, choice of steroid-sparing agents, and biopsy practice. To promote guideline adherence and reduce practice variation, factors driving this variation should be assessed and resolved. What is Known: • National and international guidelines are available to guide the management of childhood nephrotic syndrome. • Several aspects of the management of childhood nephrotic syndrome, including the choice of steroid-sparing drugs and biopsy practice, are controversial and often debated among physicians. What is New: • Significant practice variation is present in the management of childhood nephrotic syndrome in the Netherlands, especially in the treatment of FRNS, SDNS, and SRNS. • The recommendation on the steroid treatment of a first episode of nephrotic syndrome in the KDIGO guideline leaves room for interpretation and is likely the cause of substantial differences in steroid-tapering practices among Dutch pediatricians and pediatric nephrologists.

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

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

Therapeutic drug monitoring of mycophenolate mofetil in pediatric patients: novel techniques and current opinion

Introduction: Mycophenolate mofetil (MMF) is an ester prodrug of the immunosuppressant mycophenolic acid (MPA) and is recommended and widely used for maintenance immunosuppressive therapy in solid organ and stem-cell transplantation as well as in immunological kidney diseases. MPA is a potent, reversible, noncompetitive inhibitor of the inosine monophosphate dehydrogenase (IMPDH), a crucial enzyme in the de novo purine synthesis in T- and B-lymphocytes, thereby inhibiting cell-mediated immunity and antibody formation. The use of therapeutic drug monitoring (TDM) of MMF is still controversial as outcome data of clinical trials are equivocal. Areas covered: This review covers in great depth the existing literature on TDM of MMF in the field of pediatric (kidney) transplantation. In addition, the relevance of TDM in immunological kidney diseases, in particular childhood nephrotic syndrome is highlighted. Expert opinion: TDM of MMF has the potential to optimize therapy in pediatric transplantation as well as in nephrotic syndrome. Limited sampling strategies to estimate MPA exposure increase its feasibility. Future perspectives rather encompass approaches reflecting total immunosuppressive load than single drug TDM.

Generation and Validation of a Limited Sampling Strategy to Monitor Mycophenolic Acid Exposure in Children With Nephrotic Syndrome

BACKGROUND

Mycophenolate mofetil (MMF) plays an increasingly important role in the treatment of children with nephrotic syndrome, especially in steroid sparing protocols. Recent publications show the relationship of exposure to its active moiety mycophenolic acid (MPA) and clinical efficacy. Performance of full-time pharmacokinetic (PK) profiles, however, is inconvenient and laborious. Established limited sampling strategies (LSS) to estimate the area under the concentration (AUC) versus time curve of MPA (MPA-AUC) in pediatric renal transplant recipients cannot be easily transferred to children suffering from nephrotic syndrome, mainly because of the lack of concomitant immunosuppressive therapy. We therefore aimed for the generation and validation of a LSS to estimate MPA exposure to facilitate therapeutic drug monitoring in children with nephrotic syndrome.

METHODS

We performed 27 complete PK profiles in 23 children in remission [mean age (±SD):12.3 ± 4.26 years] to generate and validate an LSS. Sampling time points were before administration (C0) and 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours after the administration of MMF. MPA was measured by enzyme multiplied immunoassay technique. There was no concomitant treatment with calcineurin inhibitors.

RESULTS

Mean daily dose of MMF was 927 ± 209 mg/m of body surface area resulting in a mean MPA-AUC0-12 value of 59.2 ± 29.3 mg × h/L and a predose level of 3.03 ± 2.24 mg/L. Between-patient variability of dose-normalized MPA-AUC0-12 was high (coefficient of variation: 45.5%). Correlation of predose levels with the corresponding MPA-AUC0-12 was moderate (r = 0.59) in a subgroup of 18 patients (20 PK profiles, generation group). An algorithm based on 3 PK sampling time points during the first 2 hours after MMF dosing (estimated AUC0-12 = 8.7 + 4.63 × C0 + 1.90 × C1 + 1.52 × C2) was able to predict MPA-AUC with a low percentage prediction error (3.88%) and a good correlation of determination (r = 0.90). Validation of this algorithm in a randomized separate group of 6 patients (7 PK profiles, validation group) resulted in comparably good correlation (r = 0.95) and low percentage prediction error (5.57%).

CONCLUSIONS

An abbreviated profile within the first 2 hours after MMF dosing gives a good estimate of MPA exposure in children with nephrotic syndrome and hence has the potential to optimize MMF therapy.

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.

Low-dose corticosteroid and mycophenolate for primary treatment of minimal change disease

BACKGROUND

Mycophenolate has been shown to be effective in glomerular disease. However, the role of mycophenolate in the first-line treatment of adult-onset idiopathic minimal change disease (MCD) has not been systematically studied in a randomized fashion.

AIM

To evaluate the therapeutic efficacy of enteric-coated mycophenolate sodium combined with low-dose corticosteroid as first-line treatment for MCNS.

DESIGN

A prospective, open-label, randomized clinical trial.

METHODS

Twenty adult patients with biopsy proven MCD were recruited and randomly assigned to receive either enteric-coated Mycophenolate Sodium (EC-MPS) plus low-dose prednisolone (Group 1: Prednisolone 0.25 mg/kg/day, n = 10) or standard-dose prednisolone (Group 2: Prednisolone 1 mg/kg/day, n = 10).

RESULTS

After 24 weeks of therapy, eight patients in Group 1 vs. seven of patients in Group 2 achieved complete remission (P = 0.606). Both groups showed a significant reduction of urine protein excretion (P < 0.05) and increased serum albumin (P < 0.001) vs. baseline levels. However, no significant between-group differences were demonstrated. The relapse rate was also similar in both groups. Both treatment regimens were well tolerated but there were more patient reported adverse effects in the standard-dose prednisolone group.

CONCLUSION

EC-MPS plus low-dose prednisolone is non-inferior to standard-dose prednisolone therapy in inducing clinical remission and preventing relapse in adult-onset idiopathic MCD and is associated with better tolerability and less adverse effects. This trial is registered with the ClinicalTrials.gov number NCT01185197.

Non-corticosteroid immunosuppressive medications for steroid-sensitive nephrotic syndrome in children

BACKGROUND

About 80% of children with steroid-sensitive nephrotic syndrome (SSNS) have relapses. Of these children, half relapse frequently, and are at risk of adverse effects from corticosteroids. While non-corticosteroid immunosuppressive medications prolong periods of remission, they have significant potential adverse effects. Currently, there is no consensus about the most appropriate second-line agent in children who are steroid sensitive, but who continue to relapse. In addition, these medications could be used with corticosteroids in the initial episode of SSNS to prolong the period of remission. This is the fourth update of a review first published in 2001 and updated in 2005, 2008 and 2013.

OBJECTIVES

To evaluate the benefits and harms of non-corticosteroid immunosuppressive medications in SSNS in children with a relapsing course of SSNS and in children with their first episode of nephrotic syndrome.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 10 March 2020 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) or quasi-RCTs were included if they involved children with SSNS and compared non-corticosteroid immunosuppressive medications with placebo, corticosteroids (prednisone or prednisolone) or no treatment; compared different non-corticosteroid immunosuppressive medications or different doses, durations or routes of administration of the same non-corticosteroid immunosuppressive medication.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias of the included studies and extracted data. Statistical analyses were performed using a random-effects model and results expressed as risk ratio (RR) for dichotomous outcomes or mean difference (MD) for continuous outcomes with 95% confidence intervals (CI). The certainty of the evidence was assessed using GRADE.

MAIN RESULTS

We identified 43 studies (91 reports) and included data from 2428 children. Risk of bias assessment indicated that 21 and 24 studies were at low risk of bias for sequence generation and allocation concealment respectively. Nine studies were at low risk of performance bias and 10 were at low risk of detection bias. Thirty-seven and 27 studies were at low risk of incomplete and selective reporting respectively. Rituximab (in combination with calcineurin inhibitors (CNI) and prednisolone) versus CNI and prednisolone probably reduces the number of children who relapse at six months (5 studies, 269 children: RR 0.23, 95% CI 0.12 to 0.43) and 12 months (3 studies, 198 children: RR 0.63, 95% CI 0.42 to 0.93) (moderate certainty evidence). At six months, rituximab resulted in 126 children/1000 relapsing compared with 548 children/1000 treated with conservative treatments. Rituximab may result in infusion reactions (4 studies, 252 children: RR 5.83, 95% CI 1.34 to 25.29). Mycophenolate mofetil (MMF) and levamisole may have similar effects on the number of children who relapse at 12 months (1 study, 149 children: RR 0.90, 95% CI 0.70 to 1.16). MMF may have a similar effect on the number of children relapsing compared to cyclosporin (2 studies, 82 children: RR 1.90, 95% CI 0.66 to 5.46) (low certainty evidence). MMF compared to cyclosporin is probably less likely to result in hypertrichosis (3 studies, 140 children: RR 0.23, 95% CI 0.10 to 0.50) and gum hypertrophy (3 studies, 144 children: RR 0.09, 95% CI 0.07 to 0.42) (low certainty evidence). Levamisole compared with steroids or placebo may reduce the number of children with relapse during treatment (8 studies, 474 children: RR 0.52, 95% CI 0.33 to 0.82) (low certainty evidence). Levamisole compared to cyclophosphamide may make little or no difference to the risk for relapse after 6 to 9 months (2 studies, 97 children: RR 1.17, 95% CI 0.76 to 1.81) (low certainty evidence). Cyclosporin compared with prednisolone may reduce the number of children who relapse (1 study, 104 children: RR 0.33, 95% CI 0.13 to 0.83) (low certainty evidence). Alkylating agents compared with cyclosporin may make little or no difference to the risk of relapse during cyclosporin treatment (2 studies, 95 children: RR 0.91, 95% CI 0.55 to 1.48) (low certainty evidence) but may reduce the risk of relapse at 12 to 24 months (2 studies, 95 children: RR 0.51, 95% CI 0.35 to 0.74), suggesting that the benefit of the alkylating agents may be sustained beyond the on-treatment period (low certainty evidence). Alkylating agents (cyclophosphamide and chlorambucil) compared with prednisone probably reduce the number of children, who experience relapse at six to 12 months (6 studies, 202 children: RR 0.44, 95% CI 0.32 to 0.60) and at 12 to 24 months (4 studies, 59 children: RR 0.20, 95% CI 0.09 to 0.46) (moderate certainty evidence). IV cyclophosphamide may reduce the number of children with relapse compared with oral cyclophosphamide at 6 months (2 studies, 83 children: RR 0.54, 95% CI 0.34 to 0.88), but not at 12 to 24 months (2 studies, 83 children: RR 0.99, 95% CI 0.76 to 1.29) and may result in fewer infections (2 studies, 83 children: RR 0.14, 95% CI 0.03 to 0.72) (low certainty evidence). Cyclophosphamide compared to chlorambucil may make little or no difference in the risk of relapse after 12 months (1 study, 50 children: RR 1.31, 95% CI 0.80 to 2.13) (low certainty evidence).

AUTHORS' CONCLUSIONS

New studies incorporated in this review indicate that rituximab is a valuable additional agent for managing children with steroid-dependent nephrotic syndrome. However, the treatment effect is temporary, and many children will require additional courses of rituximab. The long-term adverse effects of this treatment are not known. Comparative studies of CNIs, MMF, levamisole and alkylating agents have demonstrated little or no differences in efficacy but, because of insufficient power; clinically important differences in treatment effects have not been completely excluded.

Long-term outcome of Japanese children with complicated minimal change nephrotic syndrome treated with mycophenolate mofetil after cyclosporine

BACKGROUND

Although recent studies have shown that more than half of children with steroid-dependent nephrotic syndrome (SDNS) may continue to have active disease beyond childhood, the long-term outcome in this cohort treated with mycophenolate mofetil (MMF) after cyclosporine remains unknown, particularly in adulthood.

METHODS

We conducted a retrospective study of 44 adult patients (median age, 22.3 years) who received MMF for complicated SDNS (median age at MMF initiation, 13.3 years) at a single center. Complicated SDNS was defined as the case continuing to relapse after cyclosporine (CsA) treatment. When patients experienced relapses despite MMF initiation, they additionally received a rituximab infusion. The primary endpoint was the probability of achieving treatment-free remission for > 2 years.

RESULTS

Prior to MMF initiation, all patients received CsA for a median of 46 months and 19 received the 12-week cyclophosphamide. After switching from CsA to MMF, only four patients did not relapse during a median follow-up period of 9.6 years. At the last visit, only 15 of the 44 patients achieved treatment-free sustained remission. Multivariate analysis revealed that young age (< 6 years) at onset of nephrotic syndrome (odds ratio, 11.3) and the experience of steroid dependency during initial CsA treatment (odds ratio, 29.8) were the independent risk factors of active disease into adulthood after MMF initiation.

CONCLUSIONS

Although none developed renal insufficiency and severe adverse effects of therapy, the introduction of MMF after CsA treatment may not be necessarily associated with improved long-term outcome of children with complicated SDNS.

Efficacy and acceptability of immunosuppressive agents for pediatric frequently-relapsing and steroid-dependent nephrotic syndrome: A network meta-analysis of randomized controlled trials

INTRODUCTION

A network meta-analysis was conducted to regard the effects of available immunosuppressive medications in pediatric frequently-relapsing nephrotic syndrome (FRNS) and steroid-dependent nephrotic syndrome (SDNS).

METHODS

We reviewed systematically 26 randomized controlled trials (1311 patients) that compared any of the following immunosuppressive agents to placebo/nontreatment (P/NT) or another drug for FRNS/SDNS treatment in children.

RESULTS

The main outcomes were efficacy and acceptability. At the 6-month, cyclophosphamide, chlorambucil, levamisole, and rituximab had better efficacy than P/NT (odds ratio [OR]: 0.09, 0.03, 0.28, and 0.07, respectively); cyclophosphamide was significantly more effective than azathioprine and chlorambucil. At 12 months, cyclophosphamide, chlorambucil, cyclosporine, levamisole, and rituximab had better efficacy than P/NT (0.10, 0.03, 0.10, 0.23, and 0.07, respectively); Chlorambucil were found to be more efficacious than levamisole and MMF (0.12 and 0.09, respectively). At 24 months, cyclophosphamide, chlorambucil, and levamisole had better efficacy than P/NT (0.09, 0.04, and 0.03, respectively); cyclophosphamide had better efficacy than cyclosporine and vincristine (0.17 and 0.39, respectively).

CONCLUSION

No significant differences in acceptability were found. Our results suggest that cyclophosphamide may be preferred initially in children with FRSN/SDNS, chlorambucil, and rituximab may be acceptable medications for patients with FRSN/SDNS. Long-term follow-up trials focused on gonadal toxicity and limitation of maximum dosage of cyclophosphamide should been carried out.

Effect of different rituximab regimens on B cell depletion and time to relapse in children with steroid-dependent nephrotic syndrome

BACKGROUND

Several studies have demonstrated that rituximab (RTX) improves relapse-free survival in patients with steroid-dependent nephrotic syndrome (SDNS). However, these studies used various RTX regimens and there are few data comparing these regimens in children with SDNS. In this retrospective study, we assessed the effect of three different initial RTX regimens on both time to B cell reconstitution and to first relapse.

METHODS

Sixty-one SDNS patients receiving a first course of RTX were included. Group 1 received one injection of 100 mg/m², group 2 received one injection of 375 mg/m², and group 3 received two injections of 375 mg/m² at day 0 and day 7. Time to B cell reconstitution and time to first relapse and respective risk factors were studied.

RESULTS

Median time to B cell reconstitution was 2.5 [1.8-3.5], 5.0 [3.9-6.0], and 6.6 [4.6-7.8] months in groups 1, 2, and 3, respectively. RTX regimen was associated with time to B cell reconstitution (HRs group 2 vs. 3, 4.07 [1.96-8.48]; group 1 vs. 3, 11.13 [4.04-30.67]). One-year relapse-free survival was 50% [58-77], 59% [42-76], and 72% [46-87] in groups 1, 2, and 3, respectively. RTX regimen was associated with risk of relapse (HRs group 2 vs. 3, 1.55 [0.51-4.65]; group 1 vs. 3, 4.98 [1.15-21.60]).

CONCLUSIONS

The initial dose of rituximab impacts time to B cell reconstitution and the probability of relapse. Risk of relapse is also associated with patient characteristics, suggesting that RTX regimen could be modified for each patient to balance efficacy, cost, and side effects.

Mycophenolate mofetil for sustained remission in nephrotic syndrome

The clinical application of mycophenolate mofetil (MMF) has significantly widened beyond the prophylaxis of acute and chronic rejections in solid organ transplantation. MMF has been recognized as an excellent treatment option in many immunologic glomerulopathies. For children with frequently relapsing nephrotic syndrome (FRNS) or steroid-dependent nephrotic syndrome (SDNS) experiencing steroid toxicity, MMF has been recommended as a steroid-sparing drug. Uncontrolled studies in patients with FRNS and SDSN have shown that many patients can achieve sustained remission of proteinuria with MMF monotherapy. Three randomized controlled trials have similarly demonstrated that MMF is beneficial in these patients, but less effective than the calcineurin inhibitors cyclosporin A or tacrolimus. Some, but not all, patients with steroid-resistant nephrotic syndrome (SRNS) may also respond to MMF, usually given in combination with other drugs, with partial or complete remission. There are important limitations to the interpretation and comparability of these studies including study design, sample size, patient selection, clinical endpoints, carry-over effects, and duration of follow-up. In all studies, MMF had relatively few side effects, no nephrotoxicity, or no systemic toxicity. MMF is teratogenic, and contraceptive advice is required in females. There is a poor correlation between MMF dose and mycophenolic acid (MPA) exposure and significant inter- and intra-patient variability in drug pharmacokinetics. A higher estimated MPA-AUC_0-12 target range than recommended for pediatric renal transplant recipients is essential to prevent relapses. Therefore, therapy should be guided by drug monitoring to avoid relapses. Further studies are needed to test the efficacy of MMF in inducing remission and, as part of a combination therapy, achieving sustained remission in patients with SRNS.

Initial treatment of steroid-sensitive idiopathic nephrotic syndrome in children with mycophenolate mofetil versus prednisone: protocol for a randomised, controlled, multicentre trial (INTENT study)

INTRODUCTION

Idiopathic nephrotic syndrome is the most common glomerular disease in childhood with an incidence of 1.8 cases per 100 000 children in Germany. The treatment of the first episode implies two aspects: induction of remission and sustainment of remission. The recent Kidney Disease Improving Global Outcomes, American Academy of Pediatrics and German guidelines for the initial treatment of the first episode of a nephrotic syndrome recommend a 12-week course of prednisone. Despite being effective, this treatment is associated with pronounced glucocorticoid-associated toxicity due to high-dose prednisone administration over a prolonged period of time. The aim of the INTENT study (Initial treatment of steroid-sensitive idiopathic nephrotic syndrom in children with mycophenolate mofetil versus prednisone: protocol for a randomised, controlled, multicentre trial) is to show that an alternative treatment regimen with mycophenolic acid is not inferior regarding sustainment of remission, but with lower toxicity compared with treatment with glucocorticoids only.

METHODS AND DESIGN

The study is designed as an open, randomised, controlled, multicentre trial. 340 children with a first episode of steroid-sensitive nephrotic syndrome and who achieved remission by a standard prednisone regimen will be enrolled in the trial and randomised to one of two treatment arms. The standard care group will be treated with prednisone for a total of 12 weeks; in the experimental group the treatment is switched to mycophenolate mofetil, also for a total of 12 weeks in treatment duration. The primary endpoint is the occurrence of a treated relapse within 24 months after completion of initial treatment.

ETHICS AND DISSEMINATION

Ethics approval for this trial was granted by the ethics committee of the Medical Faculty of the University of Heidelberg (AFmu-554/2014). The study results will be published in accordance with the Consolidated Standards of Reporting Trials statement and the Standard Protocol Items: Recommendations for Interventional Trials guidelines. Our findings will be submitted to major international paediatric nephrology and general paediatric conferences and submitted for publication in a peer-reviewed, open-access journal.

TRIAL REGISTRATION NUMBER

DRKS0006547; EudraCT2014-001991-76; Pre-result.

DATE OF REGISTRATION

30 October 2014; 24 February 2017.

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.

[Treatments of steroid-dependent nephrotic syndrome in children]

Primary nephrotic syndrome (NS) is the most common glomerular disease in children. It is characterized by massive proteinuria and hypoalbuminemia. It typically has a sudden onset and more than 70% of patients will experience at least one relapse. An immunological origin has long been postulated, although the precise molecular mechanisms underlying the disease remain debated. Steroids are the first-line therapy with cumulative dose and duration of initial treatment varying among countries. Steroid-sparing agents may be indicated in case of steroid-dependency or frequent relapses. However, no consensus exists regarding the different treatment options. These treatments are mostly suspensive and therefore, need to be prolonged for several months. Levamisole, an antihelminthic drug, also has an immunomodulatory function, and alone or in combination with steroids, it can decrease cumulative steroid dose and relapses. It is usually well tolerated, and its principal side effects are cytopenia and elevated liver enzymes. Mycophenolate mofetil is an immunosuppressive agent whose reported side effects are cytopenia and diarrhea. Calcineurin inhibitors (cyclosporine or tacrolimus) have long been used in steroid-dependent patients. Their major side effects are hirsutism, gum hypertrophy, and nephrotoxicity, leading to interstitial kidney fibrosis and chronic kidney disease. Cyclophosphamide is an efficient treatment but its gonadal toxicity is a major drawback to its use. More recent drugs such as rituximab are very effective but require hospitalization for the infusion and induce an increased risk of opportunistic infection, prolonged neutropenia, and anaphylaxis. In this review, we present the available treatments, their indications, and the side effects.

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.

Nephrotoxicity in children with frequently relapsing nephrotic syndrome receiving long-term cyclosporine treatment

BACKGROUND

Steroid-sparing drugs, such as cyclosporine, are recommended as treatment for children with frequently relapsing nephrotic syndrome (FRNS) and steroid-related toxicities. We recently reported a high rate of relapsing nephrotic syndrome 2 years after discontinuation of cyclosporine treatment, suggesting that long-term treatment is necessary. Cyclosporine-associated nephrotoxicity (CAN) is a potential side effect of long-term cyclosporine treatment.

METHODS

We retrospectively reviewed pediatric patients with FRNS treated with cyclosporine for ≥3 years at a single center between 1999 and 2012. The cyclosporine dose was adjusted to maintain the whole-blood cyclosporine trough level at 80-100 ng/ml for 6 months, at 60-80 ng/ml for 18 months, and then at around 50-60 ng/ml thereafter. Maintenance dose of prednisolone was not prescribed. CAN was graded in terms of arteriolar hyalinosis and the degree of interstitial fibrosis.

RESULTS

Thirty-six children (28 males) were enrolled in the study. The median age at the start of long-term cyclosporine treatment was 9.4 years. The median duration of the longest period of cyclosporine treatment was 4.5 years. Most CAN cases were characterized by arteriolar hyalinosis. The frequency of CAN was positively correlated with the duration of cyclosporine treatment, with an odds ratio (95% confidence interval) for CAN of 3.84 (0.79-18.74) after 2-5 years and 6.60 (1.18-36.94) after >5 years of cyclosporine treatment (vs. 0-2 years).

CONCLUSIONS

Although the frequency of CAN was correlated with the duration of cyclosporine treatment in our pediatric patient population, most cases of CAN involved arteriolar hyalinosis. We conclude that long-term cyclosporine treatment is useful for treating FRNS in children, providing its dose is controlled and kidney biopsies are regularly performed.

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.

The Roche Total Mycophenolic Acid® assay: An application protocol for the ABX Pentra 400 analyzer and comparison with LC-MS in children with idiopathic nephrotic syndrome

Background

For TDM of mycophenolate acid (MPA), the Roche Total Mycophenolic Acid® assay based on the inhibition of recombinant inosine monophosphate dehydrogenase (IMPDH) has been shown to be a simple and reliable alternative to chromatographic methods. We have adapted this assay on the ABX Pentra 400 analyzer (HORIBA).

Objective

To investigate the analytical performances of the Roche Total Mycophenolic Acid® assay on the ABX Pentra 400 and to compare it to an LC-MS method using samples from children with nephrotic syndrome treated with mycophenolate mofetil (MMF).

Material and methods

Configuration of the open-channel on the ABX Pentra 400 was based on the Roche MPA assay package insert. Precision was determined as described in the CLSI protocol EP5-A2. Comparison with the LC-MS method was performed using 356 plasma samples from 42 children with nephrotic syndrome (8 h pharmacokinetic profiles).

Results

The enzymatic assay demonstrated high precision. The %CV for Within Run Imprecision ranged from 5.5% at 1.2 mg/L to 1.5% at 14.1 mg/L and Total Imprecision ranged from 9.3% to 2.5%. The method comparison with plasma samples from children yielded overall a good correlation and a good agreement between both methods. The Passing Bablok regression analysis showed the following results: [Roche MPA assay]=1.058 [MPA LC-MS] −0.06; rho=0.996.

Conclusion

The Roche Total Mycophenolic Acid® assay is adaptable to the ABX Pentra 400 analyzer, and demonstrates accurate and precise measurement of MPA in plasma obtained from children with nephrotic syndrome.

•

Adaptation of the Roche Total Mycophenolic Acid® assay to the Pentra 400 analyzer.

•

Comparison with LC-MS in children with idiopathic nephrotic syndrome.

•

Therapeutic drug monitoring of mycophenolate mofetil.

Mycophenolate Mofetil Therapy in Children With Idiopathic Nephrotic Syndrome: Does Therapeutic Drug Monitoring Make a Difference?

BACKGROUND

Idiopathic nephrotic syndrome (INS) necessitates administration of corticosteroids or corticoid-sparing agents in 60% of the cases for prolonged periods resulting in serious adverse effects.

METHODS

To avoid these complications, we investigated the efficacy and safety of mycophenolate mofetil (MMF) in our retrospective single-center study with 15 patients presenting with complicated courses of INS and aspired to estimate a cutoff level for mycophenolic acid-area under the curve (MPA-AUC) values, which can predict relapses with high sensitivity.

RESULTS

Seven of 15 patients stayed in remission while receiving MMF. Average frequency of relapses was 1.39 (0.28-2.5) per year. In case of relapses, patients had lower predose and estimated AUC0-12 levels of MPA (P = 0.02 and 0.001, respectively). Based on the results of receiver operating characteristic analysis, we consider an estimated MPA-AUC0-12 lower than 44.6 mg·h·L(-1) as a risk factor for future relapses (91% sensitivity, 57% specificity, P = 0.06) because the prevalence of relapse is significantly lower (0.07 versus 0.5, P = 0.02), if the estimated MPA-AUC0-12 is >44.6 mg·h·L(-1). During MMF administration, we did not detect any adverse event requiring discontinuation of treatment.

CONCLUSIONS

In conclusion, we demonstrate MMF as an alternative treatment for children with complicated INS to maintain remission without serious side effects. Furthermore, we propose a higher therapeutic target range of MPA-AUC0-12 (>45 mg·h·L(-1)) than used in transplanted children underlining the crucial role of therapeutic drug monitoring.

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.

Mycophenolate mofetil in steroid-dependent idiopathic nephrotic syndrome

BACKGROUND

Prospective studies have established the mycophenolate mofetil (MMF) efficiency in childhood idiopathic nephrotic syndrome (INS) but reports on the long-term outcome are lacking. Moreover, the search for factors influencing its efficiency would be useful to define its place among the other treatments.

METHODS

We performed a monocentric retrospective study including 96 children with steroid-dependent INS followed for 4.7 years (median) (IQ 3-6) after the onset of MMF treatment. The characteristics of responder patients (n = 74), as defined by a 50 % decrease of relapse rate and/or a 60 % decrease of steroid dose, and of non-responder patients (n = 22) were compared by univariate analysis and multivariate logistic regression.

RESULTS

Withdrawal of prednisone was achieved in 48/96 patients after a median duration of 18.1 months (IQ 7.8-30.0) of MMF. Only 26/48 patients did not relapse under MMF alone. After MMF was stopped in these patients, only six remained in remission without any treatment at last follow-up. Responders had a shorter time to remission at the first flare (9.5 vs. 15 days, p = 0.02), a shorter disease duration prior to the onset of MMF (22.2 vs. 94.5 months, p = 0.001), and were younger at the MMF initiation (6.7 vs. 10.1 years, p = 0.02) than non-responder patients. The age of MMF initiation was an independent factor associated with efficiency (OR = 0.80, 95 % CI [0.69, 0.93], p < 0.01).

CONCLUSIONS

MMF is more efficient in young patients treated early in the disease course. Nevertheless, MMF has no remnant effect while nearly all patients relapsed after withdrawal of the drug.

Mycophenolic Acid Pharmacokinetics and Relapse in Children with Steroid-Dependent Idiopathic Nephrotic Syndrome

BACKGROUND AND OBJECTIVES

Therapeutic drug monitoring of mycophenolic acid can improve clinical outcome in organ transplantation and lupus, but data are scarce in idiopathic nephrotic syndrome. The aim of our study was to investigate whether mycophenolic acid pharmacokinetics are associated with disease control in children receiving mycophenolate mofetil for the treatment of steroid-dependent nephrotic syndrome.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a retrospective multicenter study including 95 children with steroid-dependent nephrotic syndrome treated with mycophenolate mofetil with or without steroids. Area under the concentration-time curve of mycophenolic acid was determined in all children on the basis of sampling times at 20, 60, and 180 minutes postdose, using Bayesian estimation. The association between a threshold value of the area under the concentration-time curve of mycophenolic acid and the relapse rate was assessed using a negative binomial model.

RESULTS

In total, 140 areas under the concentration-time curve of mycophenolic acid were analyzed. The findings indicate individual dose adaptation in 53 patients (38%) to achieve an area under the concentration-time curve target of 30-60 mg·h/L. In a multivariable negative binomial model including sex, age at disease onset, time to start of mycophenolate mofetil, previous immunomodulatory treatment, and concomitant prednisone dose, a level of area under the concentration-time curve of mycophenolic acid >45 mg·h/L was significantly associated with a lower relapse rate (rate ratio, 0.65; 95% confidence interval, 0.46 to 0.89; P=0.01).

CONCLUSIONS

Therapeutic drug monitoring leading to individualized dosing may improve the efficacy of mycophenolate mofetil in steroid-dependent nephrotic syndrome. Additional prospective studies are warranted to determine the optimal target for area under the concentration-time curve of mycophenolic acid in this population.

Evaluation of mycophenolate mofetil or tacrolimus in children with steroid sensitive but frequently relapsing or steroid-dependent nephrotic syndrome

AIM

Approximately 30-40% of children with steroid sensitive nephrotic syndrome have frequently relapsing nephrotic syndrome (FRNS) or steroid-dependent nephrotic syndrome (SDNS). Mycophenolate mofetil (MMF) and tacrolimus (TAC) are often alternative treatment choices for these patients.

METHODS

A single-center prospective study was conducted to compare the efficacy of MMF or TAC in reducing relapses and maintaining remission in children with FRNS or SDNS. Of the 72 recruited patients, either MMF (20∼30 mg/kg/d, n = 34) or TAC (0.05∼0.15 mg/kg/d, n = 38) was administered for 12 months.

RESULTS

The mean 6-month relapse rates decreased from 2.56 episodes before therapy to 0.76 episodes in the first 6 months after therapy (c(2) = 44.362, p < 0.001) and 0.67 in the next 6 months (c(2) = 37.817, p < 0.001) in the MMF group. In the TAC group, the mean 6-month relapse rates decreased from 2.39 episodes before therapy to 0.41 episodes in the first 6 months after therapy (c(2) = 62.242, p < 0.001) and 0.42 in next 6 months (c(2) = 67.482, p < 0.001). No significant difference in the relapse rate was found between the groups (before therapy, c(2) = 0.902, p = 0.637; first 6 months, c(2) = 5.358, p = 0.147; second 6 months, c(2) = 4.089, p = 0.252). And there was also no significant difference in cumulative sustained remission and the incidence of adverse events between two groups.

CONCLUSIONS

In combination with low-dose steroids, MMF or TAC presented similar efficacy in maintaining remission in children with FRNS/SDNS in the present study. Therapy with MMF or TAC is a promising strategy with a moderate risk of side effects in children who are steroid sensitive but have FRNS/SDNS.

Comparison of second-line immunosuppressants for childhood refractory nephrotic syndrome: a systematic review and network meta-analysis

Although, most patients respond initially to therapy for nephrotic syndrome, about 70% of patients have a relapse. Currently, there is no consensus about the most appropriate second-line agent in children who continue to suffer a relapse. This network meta-analysis was designed to compare the efficacy and safety of the commonly used immunosuppressive agents in second-line therapeutic agents (ie, cyclophosphamide, cyclosporine, tacrolimus and mycophenolate mofetil) for refractory childhood nephrotic syndrome. MEDLINE, Cochrane, EMBASE and Google Scholar databases were searched until October 17, 2015 using the following search terms: cyclophosphamide, cyclosporine, tacrolimus, mycophenolate mofetil and childhood nephrotic syndrome. Randomized controlled trials, prospective 2-arm studies and cohort studies were included. 7 studies with 391 patients were included. Bayesian network meta-analysis found that treatment with mycophenolate mofetil had the greatest odds of relapse compared with tacrolimus (pooled OR=49.72, 95% credibility interval (CrI) 1.65 to 2483.32), cyclophosphamide (pooled OR=72.05, 95% CrI 1.44 to 13633.33) and cyclosporine (pooled OR=11.42, 95% CrI 1.03 to 131.60). Rank probability analysis found cyclophosphamide was the best treatment with the lowest relapse rate as compared with other treatments (rank probability=0.58), and tacrolimus was ranked as the second best (rank probability=0.38). Our findings support the use of cyclophosphamide and tacrolimus in treating children with relapsing nephrotic syndrome.

Long-term efficacy and safety of common steroid-sparing agents in idiopathic nephrotic children

BACKGROUND

Calcineurin inhibitors (CNI), mycophenolate mofetil (MMF), and levamisole are common treatment choices for patients with frequently relapsing (FRNS) and steroid-dependent nephrotic syndrome (SDNS).

METHODS

In this retrospective cohort study, we analyzed the relative efficacy and safety of tacrolimus, MMF, and levamisole over a period of 30 months, in treating 340 children with idiopathic FRNS/SDNS. The children received either MMF 1200 mg/m² daily, or levamisole 2.5 mg/kg on alternate days, or tacrolimus 0.1-0.2 mg/kg daily along with tapering doses of alternate-day prednisolone.

RESULTS

Tacrolimus was associated with a higher rate of 30-month relapse-free survival when compared to MMF (61.7 vs. 38.5 %, p < 0.001), or levamisole (61.7 vs. 24 %, p < 0.001). However, relapse rate increased almost threefold once tacrolimus was stopped, resulting in a higher relapse rate per patient-year when compared to the MMF group (2.0 vs. 1.5, p = 0.013). The cumulative prednisolone dose per patient during the last year of the study period was also increased among tacrolimus group in comparison with MMF group (96.4 vs. 74.4 mg/kg/year, p = 0.004). Independent of the impact of drug choice, the relapse risk was higher in patients with steroid dependency at baseline (HR 2.14, 95 %CI 1.79-2.96, p < 0.0001). In comparison with few minor adverse events in other two cohorts, several serious adverse events were documented in the tacrolimus group.

CONCLUSIONS

Although there are serious safety concerns regarding tacrolimus, it is more effective than MMF or levamisole in maintaining relapse-free survival. However, unlike MMF, the relative efficacy of tacrolimus in preventing further relapses is seen only when the patient is on the drug. Taking together the long-term efficacy and safety data observed, MMF appears as a safe and effective alternative to tacrolimus in managing pediatric FRNS/SDNS.

Steroid-sensitive nephrotic syndrome: an evidence-based update of immunosuppressive treatment in children

Nephrotic syndrome is one of the most common paediatric glomerular diseases, with an incidence of around two per 100,000 children per year. Corticosteroids are the mainstay of treatment, with 85%-90% of children going into remission with an 8-week course of treatment. Unfortunately, nephrotic syndrome follows a relapsing and remitting course in the majority, with 90% relapsing at least once. About half will progress to frequently relapsing nephrotic syndrome (FRNS) or steroid-dependent nephrotic syndrome (SDNS). Different initial steroid regimens have been evaluated since the first trials in Europe and America in the 1960s. Most trials have been designed to evaluate the optimal duration of the initial therapy, rather than different cumulative doses of corticosteroid, or the management of relapses. Until recently, these data suggested that an initial treatment duration of up to 6 months reduced the number of children developing a relapse, without evidence of increased steroid toxicity. Recently, three large, well-designed randomised control trials were published, which demonstrated no significant reduction in risk of relapse or of developing FRNS by extended treatment compared with 2 or 3 months. While there are few trial data to guide the treatment of individual relapses in steroid-sensitive nephrotic syndrome (SSNS), there is some evidence that a short course of corticosteroid therapy during upper respiratory tract infection may prevent relapse. In patients with FRNS or SDNS who continue to relapse despite low-dose alternate-day steroids a number of non-corticosteroid, steroid-sparing immunosuppressive agents (cyclophosphamide, ciclosporin, tacrolimus, mycophenolate mofetil, levamisole, rituximab) have been shown to reduce the risk of relapse and of FRNS. However, there are limited head-to-head data to inform which agent should be preferred. In this article, we review recent data from randomised trials to update paediatricians on the current evidence supporting interventions in SSNS.

[Comparison of therapeutic effects of prednisone combined with mycophenolate mofetil versus cyclosporin A in children with steroid-resistant nephrotic syndrome]

OBJECTIVE

To compare the therapeutic effects of prednisone combined with mycophenolate mofetil (MMF) versus cyclosporin A (CsA) in children with steroid-resistant nephrotic syndrome (SRNS).

METHODS

The clinical data of 164 SRNS children who were treated with prednisone combined with MMF or CsA between January 2004 and December 2013 were collected, and the clinical effect of prednisone combined with MMF (MMF group, 112 children) or CsA (CsA group, 52 children) was analyzed retrospectively.

RESULTS

At 1 month after treatment, the CsA group had a significantly higher remission rate than the MMF group (67.3% vs 42.9%; P<0.05). At 3 months after treatment, the CsA group also had a significantly higher remission rate than the MMF group (78.8% vs 63.3%; P<0.05). The 24-hour urinary protein excretion in both groups changed significantly with time (P<0.05) and differed significantly between the two groups (P<0.05). There were no serious adverse events in the two groups.

CONCLUSIONS

Prednisone combined with MMF or CsA is effective and safe for the treatment of SRNS in children, and within 3 months of treatment, CsA has a better effect than MMF.

[Comparison of therapeutic effects of prednisone combined with mycophenolate mofetil versus cyclosporin A in children with steroid-resistant nephrotic syndrome]

OBJECTIVE

To compare the therapeutic effects of prednisone combined with mycophenolate mofetil (MMF) versus cyclosporin A (CsA) in children with steroid-resistant nephrotic syndrome (SRNS).

METHODS

The clinical data of 164 SRNS children who were treated with prednisone combined with MMF or CsA between January 2004 and December 2013 were collected, and the clinical effect of prednisone combined with MMF (MMF group, 112 children) or CsA (CsA group, 52 children) was analyzed retrospectively.

RESULTS

At 1 month after treatment, the CsA group had a significantly higher remission rate than the MMF group (67.3% vs 42.9%; P<0.05). At 3 months after treatment, the CsA group also had a significantly higher remission rate than the MMF group (78.8% vs 63.3%; P<0.05). The 24-hour urinary protein excretion in both groups changed significantly with time (P<0.05) and differed significantly between the two groups (P<0.05). There were no serious adverse events in the two groups.

CONCLUSIONS

Prednisone combined with MMF or CsA is effective and safe for the treatment of SRNS in children, and within 3 months of treatment, CsA has a better effect than MMF.

History of Nephrotic Syndrome and Evolution of its Treatment

The recognition, evaluation, and early treatment of nephrotic syndrome in infants and children originate from physicians dating back to Hippocrates. It took nearly another 1000 years before the condition was described for its massive edema requiring treatment with herbs and other remedies. A rich history of observations and interpretations followed over the course of centuries until the recognition of the combination of clinical findings of foamy urine and swelling of the body, and measurements of urinary protein and blood analyses showed the phenotypic characteristics of the syndrome that were eventually linked to the early anatomic descriptions from first kidney autopsies and then renal biopsy analyses. Coincident with these findings were a series of treatment modalities involving the use of natural compounds to a host of immunosuppressive agents that are applied today. With the advent of molecular and precision medicine, the field is poised to make major advances in our understanding and effective treatment of nephrotic syndrome and prevent its long-term sequelae.

A series of patients with minimal change nephropathy treated with rituximab during adolescence and adulthood

Background

The treatment of immune suppression dependent minimal change nephropathy (MCN) can be challenging and frequently leads to serious complications. In paediatric patients, successful treatment with rituximab is described in steroid-dependent MCN. There is limited information about the potential efficacy of rituximab for the treatment of MCN in adults and adolescence. We describe our experience with rituximab in adolescent and adult patients with immune suppression dependent MCN.

Results

Ten adolescents and adults with immune suppression dependent MCN and therapy related complications were treated with rituximab. At a mean age of 26 years, about 10.5 years after first presentation, they received two doses of rituximab (375 mg/m²). Maintenance immunosuppressive medication was stopped. After a mean follow-up of 43 months, three patients had four relapses. Three relapses were successfully retreated with rituximab again, after induction therapy with 60 mg prednisone per day. Rituximab was well tolerated and no infectious complications were recorded.

Conclusion

Treatment with rituximab induces a long-term remission of immune suppression dependent MCN in adolescents and adults. A timely treatment with rituximab could be considered to limit side effects of immunosuppressive medication.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1255-0) contains supplementary material, which is available to authorized users.

WITHDRAWN: Efficacy and Safety of Mycophenolate Mofetil Versus Levamisole in Children and Adolescents With Idiopathic Nephrotic Syndrome: Results of a Randomized Clinical Trial

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Positive role of rituximab in switching from cyclosporine to mycophenolate mofetil for children with high-dose steroid-dependent nephrotic syndrome

BACKGROUND

Recent randomized studies indicate that mycophenolate mofetil (MMF) is inferior to cyclosporine (CsA) in preventing relapses of nephrotic syndrome (NS). During the last decade, rituximab (RTX) has emerged as a rescue therapy in patients with complicated, frequently relapsing, or steroid-dependent NS.

CASE-DIAGNOSIS/TREATMENT

After introducing RTX in our single center, we analyzed 26 patients with steroid-dependent NS who had relapses while receiving long-term CsA and who were subsequently switched to MMF. MMF was adjusted to maintain a targeted predose mycophenolic acid (MPA) level of 2-5 μg/ml. Moreover, for patients who required MMF and high-dose prednisolone (PSL) to maintain remission, a single infusion of RTX (375 mg/m(2)) was added. The primary endpoint was the probability of achieving PSL-free remission for >1 year. At a mean follow-up of 28.8 ± 9.9 months, 11 of 26 patients (42 %) required RTX treatment, and 22 of those patients (85 %) achieved PSL-free sustained remission. The mean predose MPA levels for patients who achieved PSL-free sustained remission were significantly higher compared with those for patients who did not (3.1 μg/ml vs. 1.7 μg/ml, p < 0.05).

CONCLUSIONS

After RTX introduction, most patients were able to switch from CsA to MMF and achieve sustained PSL-free remission.