Update on the treatment of steroid-sensitive nephrotic syndrome

Efficacy and safety of oral cyclophosphamide versus mycophenolate mofetil in childhood nephrotic syndrome: an open-label comparative study

INTRODUCTION

There is a scarcity of research comparing the efficacy of cyclophosphamide and mycophenolate mofetil in childhood nephrotic syndrome. The aim was to evaluate the efficacy and safety of oral cyclophosphamide (CYC) and mycophenolate mofetil (MMF) in children with steroid-sensitive nephrotic syndrome in terms of the proportion of children who have been off steroids for at least 6 months without proteinuria (responders).

METHODS

This open-label retrospective-prospective comparative study was conducted in a pediatric nephrology clinic of a referral center for children between 1 and 18 years of age with FR/SD nephrotic syndrome. Group A consisted of patients who received oral cyclophosphamide (100, 25% female) at a dose of 2-2.5 mg/kg once daily for a period of 8-12 weeks. Group B consisted of patients who received oral mycophenolate mofetil (n = 61, 18% female) (dose: 800-1200 mg/m2) for at least 12 months. Responders were defined as children who were off steroids for at least 6 months along with absence of proteinuria.

RESULTS

In the CYC group, 50% of the patients were responders, whereas 54% of the patients in the MMF group were responders (p = 0.614). The time to first relapse with CYC was 7 months (IQR 5.25-11) compared to 7 months (IQR 3.5-12) with MMF (p = 0.092). The relapse rate in the CYC group was 1.77 relapses per patient-year compared to 1.295 relapses per patient-year in the MMF group. The difference in relapse rate was significant (-0.474; 95% CI, 0.09 to 0.86 relapses/person-year) (p value = 0.009). Multivariate analysis revealed that an age of less than 5 years at the start of treatment was a significant factor for a better response to MMF (p value = 0.039, OR = 2.988, CI -1.055-8.468).

CONCLUSIONS

The efficacy of MMF was similar to that of CYC in terms of response (6 months without steroids) in children with FR/SD nephrotic syndrome. MMF showed a favorable response in terms of the frequency of relapse and treatment failure. REGISTRATION OF THE STUDY WITH CLINICAL TRIALS REGISTRY OF INDIA: ( http://ctri.nic.in ;CTRI/2021/06/034421) (Dt: 28/06/2021).

Minimal Change Disease

Minimal change disease represents a common cause of nephrotic syndrome in both pediatric and adult patients. Although much remains to be discovered, there have been significant recent advancements in our understanding of the pathophysiology of minimal change disease, including the discovery of antinephrin antibodies as a marker for diagnosis of disease. Here we will review what is known about the pathophysiology, treatment, and prognosis of minimal change disease and the differences between pediatric and adult patients. Recent advances in our understanding of the mechanisms of disease will be noted. We will discuss how this may change the treatment of minimal change disease going forward and what remains to be studied.

Incidence and Pathological Patterns of Nephrotic Syndrome among Infants and Children: A Systematic Review

Nephrotic syndrome (NS) is known to be a prevalent chronic illness in young patients. Periorbital swelling in children with this condition is a recurring symptom, either with or without generalized edema. The current study aimed to examine the incidence and pattern of nephrotic syndrome in infants and children by thoroughly examining the recently available literature. A thorough search of PubMed, SCOPUS, Web of Science, Science Direct, and Google Scholar was conducted, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model, to find pertinent material. The Rayyan software (Qatar Computing Research Institute, Ar-Rayyan, Qatar) was utilized during the whole process. Data from a total of 1418 patients from nine trials were considered in this study. Numerous factors influenced the incidence, mean age, sex dominance, and histological patterns in various sample groups. The current findings conclude that variations in socioeconomic, regional, and genetic factors influence the development and pattern of these diseases. The prevalence of pediatric renal disorders differs throughout countries. Season of occurrence, response to corticosteroid treatment, and histopathologic findings appear to differ amongst the diagnosed cases.

Comparison of Urinary Beta-2 Microglobulin Levels in Children with SSNS and Calcineurin Inhibitor-Treated SRNS

Background

While the utility of beta-2 microglobulin (β2M) has been explored in various renal conditions to identify tubulointerstitial damage, it has not been adequately studied in nephrotic syndrome. The primary objective of the study was to compare urinary β2M levels in children with steroid-sensitive nephrotic syndrome (SSNS) and steroid-resistant nephrotic syndrome (SRNS) in disease remission.

Materials and Methods

This cross-sectional study was done at a tertiary care hospital between April 2019 and March 2020. Sixty children (2-18 years) with SSNS and SRNS (30 in each group) in remission were enrolled. SRNS patients were included after ≥1 year of treatment with calcineurin inhibitors (CNIs). Biochemical investigations were done to confirm remission; spot samples for urinary β2M were collected and estimation was done by an enzyme-linked immunosorbent assay (ELISA)-based kit.

Results

Of the 60 children, 63% were boys. The median (interquartile range [IQR]) age at enrollment for SSNS and SRNS patients was 7 (4.1-9) and 11 (8.3-12) years, respectively. Urinary β2M levels were significantly higher in SRNS patients compared to SSNS patients (2.6 vs. 0.75 mg/ml, P < 0.0001). Patients who received cyclosporine for >2 years had higher median urinary β2M levels compared to those who received it for a shorter period (2.63 vs. 1.83 mg/ml, P = 0.03). Median β2M levels were higher in focal segmental glomerulosclerosis than minimal change disease (3.5 vs. 2.5 mg/ml).

Conclusion

Urinary β2M levels were higher in SRNS compared to SSNS disease in remission, and β2M levels correlated well with CNI use of >2 years. It appears to be a promising noninvasive tool to identify early tubular damage and progression in patients with nephrotic syndrome, especially SRNS.

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.

Sustained Survival Benefit in Recurrent Medulloblastoma by a Metronomic Antiangiogenic Regimen: A Nonrandomized Controlled Trial

Importance

Medulloblastoma recurrence in patients who have previously received irradiation has a dismal prognosis and lacks a standard salvage regimen.

Objective

To evaluate the response rate of pediatric patients with medulloblastoma recurrence using an antiangiogenic metronomic combinatorial approach (Medulloblastoma European Multitarget Metronomic Anti-Angiogenic Trial [MEMMAT]).

Design, Setting, and Participants

This phase 2, investigator-initiated, multicenter nonrandomized controlled trial assessed 40 patients with relapsed or refractory medulloblastoma without a ventriculoperitoneal shunt who were younger than 20 years at original diagnosis. Patients were enrolled between April 1, 2014, and March 31, 2021.

Interventions

Treatment consisted of daily oral thalidomide, fenofibrate, celecoxib, and alternating 21-day cycles of low-dose (metronomic) oral etoposide and cyclophosphamide, supplemented by intravenous bevacizumab and intraventricular therapy consisting of alternating etoposide and cytarabine.

Main Outcomes and Measures

The primary end point was response after 6 months of antiangiogenic metronomic therapy. Secondary end points included progression-free survival (PFS), overall survival (OS), and quality of life. Adverse events were monitored to assess safety.

Results

Of the 40 patients (median [range] age at treatment start, 10 [4-17] years; 25 [62.5%] male) prospectively enrolled, 23 (57.5%) achieved disease control after 6 months of treatment, with a response detected in 18 patients (45.0%). Median OS was 25.5 months (range, 10.9-40.0 months), and median PFS was 8.5 months (range, 1.7-15.4 months). Mean (SD) PFS at both 3 and 5 years was 24.6% (7.9%), while mean (SD) OS at 3 and 5 years was 43.6% (8.5%) and 22.6% (8.8%), respectively. No significant differences in PFS or OS were evident based on molecular subgroup analysis or the number of prior recurrences. In patients demonstrating a response, mean (SD) overall 5-year PFS was 49.7% (14.3%), and for patients who remained progression free for the first 12 months of treatment, mean (SD) 5-year PFS was 66.7% (16.1%). Treatment was generally well tolerated. Grade 3 to 4 treatment-related adverse events included myelosuppression, infections, seizures, and headaches. One heavily pretreated patient with a third recurrence died of secondary acute myeloid leukemia.

Conclusions and Relevance

This feasible and well-tolerated MEMMAT combination regimen demonstrated promising activity in patients with previously irradiated recurrent medulloblastoma. Given these results, this predominantly oral, well-tolerated, and outpatient treatment warrants further evaluation.

Trial Registration

ClinicalTrials.gov Identifier: NCT01356290.

Rituximab therapy for childhood onset idiopathic nephrotic syndrome: experience of a Portuguese tertiary center

INTRODUCTION

Rituximab (RTX) is a therapeutic option in pediatric difficult-to-treat idiopathic nephrotic syndrome (NS). We aimed to assess the efficacy and safety of RTX use in these patients.

METHOD

A retrospective study of all patients with idiopathic NS treated with RTX was conducted in a pediatric nephrology division of a tertiary hospital. Demographic, anthropometric, clinical and analytical data were collected prior to treatment and at 6, 12, and 24 months.

RESULTS

Sixteen patients were included (11 males), with a median (25th-75th percentile, P25-P75) age at diagnosis of 2 (2.0-2.8) years. Fifteen were steroid-sensitive and 1 was steroid-resistant and sensitive to cyclosporine. The median age at administration of RTX was 10 (6.3-14.0) years. Throughout a median follow-up time of 2.5 (1.0-3.0) years, 6 (37.5%) patients achieved partial remission and 7 (43.8%) had no relapses and were not taking any immunosuppressants at the 24-month follow-up visit. Regarding complications, 1 patient presented persistent hypogammaglobulinemia. Compared with the 12-month period before RTX, there was a decrease in the median number of relapses at 6 and 12 months [3 (3.0-4.0) vs 0 (0-0.8) and 0.50 (0-1.0), respectively; p = 0.001] and in the daily steroids dose (mg/kg/day) at 6, 12, and 24 months [0.29 (0.15-0.67)vs [0.10 (0.07-0.13); p = 0.001], [0.12 (0.05-0.22); p = 0.005] and [0.07(0.04-0.18); p = 0.021]], respectively. There was also a reduction in the median BMI z score at 24 months [2.11 (0.45-3.70) vs. 2.93 (2.01-3.98); p = 0.049].

CONCLUSION

Our results confirm the efficacy and safety of RTX use in pediatric idiopathic NS and highlight its' potential cardiometabolic benefits.

Glomerular Diseases Across Lifespan: Key Differences in Diagnostic and Therapeutic Approaches

Glomerular diseases are common causes of chronic kidney disease in childhood, adolescence, and adulthood. The epidemiology of glomerular diseases differs between different age groups, with minimal change disease being the leading cause of nephrotic syndrome in childhood, while membranous nephropathy and focal segmental glomerulosclerosis are more common in adulthood. IgA vasculitis is also more common in childhood. Moreover, there is a difference in disease severity with more children presenting with a relapsing form of nephrotic syndrome and a more acute presentation of antineutrophil cytoplasmic antibody-associated vasculitis and concomitant glomerulonephritis, as highlighted by the higher percentage of cellular crescents on kidney biopsy specimens in comparison with older patients. There is also a female preponderance in antineutrophil cytoplasmic antibody-associated vasculitis and more children present with tracheobroncholaryngeal disease. This article aims to summarize differences in the presentation of different glomerular diseases that are encountered commonly by pediatric and adult nephrologists and potential differences in the management.

Use of Rituximab in Childhood Idiopathic Nephrotic Syndrome

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

Mechanisms underlying acupuncture therapy in chronic kidney disease: A narrative overview of preclinical studies and clinical trials

Chronic kidney disease (CKD) is associated with high incidence, low awareness, and high disability rates among the population. Moreover, the disease significantly affects the physical and mental health of patients. Approximately 25% of patients with CKD develop end-stage renal disease (ESRD) within 20 years of diagnosis and have to rely on renal replacement therapy, which is associated with high mortality, heavy economic burden, and symptoms including fatigue, pain, insomnia, uremia pruritus, and restless leg syndrome. Currently, the means to delay the progress of CKD are insufficient; therefore, developing strategies for delaying CKD progression has important practical implications. In recent years, more and more people are accepting the traditional Chinese medical technique "acupuncture." Acupuncture has been shown to improve the uncomfortable symptoms of various diseases through stimulation (needling, medicinal moxibustion, infrared radiation, and acupressure) of acupoints. Its application has been known for thousands of years, and its safety and efficacy have been verified. As a convenient and inexpensive complementary therapy for CKD, acupuncture has recently been gaining interest among clinicians and scientists. Nevertheless, although clinical trials and meta-analysis findings have demonstrated the efficacy of acupuncture in reducing albuminuria, improving glomerular filtration rate, relieving symptoms, and improving the quality of life of patients with CKD, the underlying mechanisms involved are still not completely understood. Few studies explored the correlation between acupuncture and renal pathological diagnosis. The aim of this study was to conduct a literature review summarizing the currently known mechanisms by which acupuncture could delay the progress of CKD and improve symptoms in patients with ESRD. This review help provide a theoretical basis for further research regarding the influence of acupuncture on renal pathology in patients with CKD, as well as the differences between specific therapeutic mechanisms of acupuncture in different renal pathological diagnosis. The evidence in this review indicates that acupuncture may produce marked effects on blocking and reversing the critical risk factors of CKD progression (e.g., hyperglycemia, hypertension, hyperlipidemia, obesity, aging, and anemia) to improve the survival of patients with CKD via mechanisms including oxidative stress inhibition, reducing inflammatory effects, improving hemodynamics, maintaining podocyte structure, and increasing energy metabolism.

Potential of soluble (pro)renin receptor in kidney disease: can it go beyond a biomarker?

(Pro)renin receptor (PRR), also termed ATPase H+-transporting accessory protein 2 (ATP6AP2), is a type I transmembrane receptor and is capable of binding and activating prorenin and renin. Apart from its association with the renin-angiotensin system, PRR has been implicated in diverse developmental, physiological, and pathophysiological processes. Within the kidney, PRR is predominantly expressed in the distal nephron, particularly the intercalated cells, and activation of renal PRR contributes to renal injury in various rodent models of chronic kidney disease. Moreover, recent evidence demonstrates that PRR is primarily cleaved by site-1 protease to produce 28-kDa soluble PRR (sPRR). sPRR seems to mediate most of the known pathophysiological functions of renal PRR through modulating the activity of the intrarenal renin-angiotensin system and provoking proinflammatory and profibrotic responses. Not only does sPRR activate renin, but it also directly binds and activates the angiotensin II type 1 receptor. This review summarizes recent advances in understanding the roles and mechanisms of sPRR in the context of renal pathophysiology.

Terapia com Rituximabe para síndrome nefrótica idiopática de início na infância: experiência de um centro terciário português

Resumo Introdução: Rituximabe (RTX) é uma opção terapêutica na síndrome nefrótica (SN) idiopática pediátrica de difícil tratamento. Visamos avaliar eficácia e segurança do uso de RTX nestes pacientes. Método: Realizou-se estudo retrospectivo de todos os pacientes com SN idiopática tratados com RTX, em uma unidade de nefrologia pediátrica de um hospital terciário. Dados demográficos, antropométricos, clínicos e analíticos foram coletados antes do tratamento e aos 6, 12 e 24 meses. Resultados: Incluímos 16 pacientes (11 do sexo masculino), com idade mediana (percentil 25–75, P25–P75) de 2 (2,0–2,8) anos ao diagnóstico. Quinze eram sensíveis a esteroides, e 1 resistente a esteroides e sensível à ciclosporina.A idade mediana na administração do RTX foi 10 (6,3–14,0) anos. Durante um tempo mediano de acompanhamento de 2,5(1,0–3,0) anos, 6 (37,5%) pacientes alcançaram remissão parcial e 7 (43,8%) não tiveram recidivas e não estavam tomando imunossupressor no acompanhamento aos 24 meses. Quanto às complicações,1 paciente apresentou hipogamaglobulinemia persistente. Comparado ao período de12 meses anterior ao RTX, houve diminuição no número mediano de recidivas em 6 e 12 meses [3 (3,0–4,0) vs 0 (0–0,8) e 0,50 (0–1,0), respectivamente; p = 0,001] e na dose diária de esteroides (mg/kg/dia) aos 6, 12 e 24 meses [0,29 (0,15–0,67) >vs [0,10 (0,07–0,13); p = 0,001], [0,12 (0,05–0,22); p = 0,005] e [0,07 (0,04–0,18); p = 0,021], respectivamente. Houve também redução na mediana do escore z do IMC aos 24 meses [2,11 (0,45–3,70) vs 2,93 (2,01–3,98);p = 0,049]. Conclusões: Nossos resultados confirmam a eficácia e segurança do uso de RTX em SN idiopática pediátrica, destacando seus potenciais benefícios cardiometabólicos.

Late Onset of ANCA Vasculitis as a Side Effect of Levamisole Treatment in Nephrotic Syndrome

Levamisole is effectively used in steroid-dependent nephrotic syndrome and the more frequent side effects reported are cytopenia and liver enzymes alterations. Several studies have demonstrated that this drug can induce high titers of circulating perinuclear antineutrophil cytoplasmic autoantibodies (ANCA) and vasculitis, most of them occurring in the case of prolonged use. A four-year-old boy that was affected with steroid-dependent nephrotic syndrome was treated with Levamisole as a steroid-sparing agent at a dose of 2 mg/kg/48 h. After initiation of the treatment, the number of relapses drastically decreased, enabling a significant reduction in the cumulative steroid dose. Levamisole was well tolerated, and was therefore administered for several years. At the age of 15, he was also diagnosed with celiac disease. After nine years of continuous Levamisole treatment, he presented with a high fever, hand and foot joint arthritis, and increased levels of total and direct bilirubin. Since the symptoms started two days after the injection of the second dose of the COVID-19 vaccine, it was initially concluded that these manifestations were rare vaccination side effects. Therefore, he did not receive any specific treatments, and Levamisole was continued at the same dose. After an initial improvement, two months later, the patient presented with the same symptoms. Suspecting Levamisole-induced vasculitis, an ANCA titer was measured and this returned positive. Clinical manifestations and double positivity for both myeloperoxidase (MPO) and anti-proteinase 3 (PR3) antibodies argued against the fact that that these findings were secondary to vaccination, cocaine abuse, or celiac disease. Assuming that we were facing a rare drug reaction, Levamisole was promptly interrupted. This resulted in a rapid remission of fever and arthritis improvement, and a decrease in ANCA titers. By reporting this case, we want to raise awareness among clinicians regarding a rare complication of treatment with Levamisole that is often misdiagnosed due to the fact that the current literature lacks univocal guidelines regarding the precise timing of ANCA titrations and the duration of the treatment.

Factors Predicting Short Term Outcome in Children With Idiopathic Nephrotic Syndrome: A Prospective Cohort Study

Objective

The objective of the article is to determine the risk factors associated with relapses in children with idiopathic nephrotic syndrome (INS).

Material and methods

Fifty-seven children with the first episode of INS were included and followed up prospectively for a minimum period of one year to identify the risk factors related to relapses. The study subjects were divided into early (less than eight days) and late (equal to or more than eight days) responder groups and were compared in terms of the number of days to achieve complete remission, time to first relapse, and the pattern of relapse at the last follow-up.

Results

Of the 57 children, 32 (56%) were male and 25 (44%) female. The mean age of the study cohort was 5.3 ± 3 years. Sixteen (55%) children with ages ranging from one to four years had a higher propensity to develop relapse, although the p-value (p=0.11) was not significant. Gender analysis did not reveal any significant correlation (p=0.32); however, a higher proportion of males (n=17; 63%) responded within eight days of starting steroids than female counterparts (n=10; 37%). Microscopic hematuria at the disease onset was seen in 12 (21%) children, and out of them, five (41.6%) remained in complete remission. The mean time to achieve complete remission was 8.1 ± 3.5 days, while the early responder group had delayed time to first relapse as compared to the late responders (3.1 ± 5.2 vs. 1.6± 3.8; p=0.21). Among all the study participants, a significant number of children (n=20; 51%) were in complete remission at their last follow-up visit. Baseline serum albumin, cholesterol, body mass index (BMI), and serum creatinine had no significant difference.

Conclusion

The delayed response to steroids and younger age at presentation can predict the time to first relapse and number of relapses in children with INS, respectively.

Idiopathic Nephrotic Syndrome in Pediatrics: An Up-to-date

BACKGROUND

Idiopathic or Primary Nephrotic Syndrome (INS) is a common glomerular disease in pediatric population, characterized by proteinuria, edema and hypoalbuminemia with variable findings in renal histopathology.

OBJECTIVE

This review aims to summarize current data on the etiopathogenesis diagnosis, protocols of treatment and potential therapeutic advances in INS.

METHODS

This narrative review searched for articles on histopathology, physiopathology, genetic causes, diagnosis and treatment of INS in pediatric patients. The databases evaluated were PubMed and Scopus.

RESULTS

INS is caused by an alteration in the permeability of the glomerular filtration barrier with unknown etiology. There are several gaps in the etiopathogenesis, response to treatment and clinical course of INS that justify further investigation. Novel advances include the recent understanding of the role of podocytes in INS and the identification of genes associated with the disease. The role of immune system cells and molecules has also been investigated. The diagnosis relies on clinical findings, laboratory exams and renal histology for selected cases. The treatment is primarily based on steroids administration. In case of failure, other medications should be tried. Recent studies have also searched for novel biomarkers for diagnosis and alternative therapeutic approaches.

CONCLUSION

The therapeutic response to corticosteroids still remains the main predictive factor for the prognosis of the disease. Genetic and pharmacogenomics tools may allow the identification of cases not responsive to immunosuppressive medications.

Cyclosporine A C1.5 monitoring reflects the area under the curve in children with nephrotic syndrome: a single-center experience

BACKGROUND

The currently used single-monitoring method for drug-blood-level evaluation in cyclosporine A (CsA) treatment for nephrotic syndrome (NS) was established through hourly measurements based on adult organ transplantation. However, the pharmacokinetics may differ due to different concomitant medications, age, and conditions. This study was conducted to determine the measurement timing that best reflects the CsA area under the curve (AUC) in pediatric NS.

METHODS

This retrospective study included children aged 2-14 years who were started on CsA treatment for idiopathic NS during 2013-2020. AUC_0-4 was calculated from 7 points, before and 0.5, 1, 1.5, 2, 3, and 4 h after administration. Mean values at each timing were compared with age-dependent different drug forms. Correlation between AUC_0-4 and measurement timing was analyzed.

RESULTS

There were 13 patients (11 boys) whose median age during testing was 7.3 years, and the total number of measurements was 94. The highest timing of CsA concentrations was found in C₁ 59.6%. The content liquid used at younger ages had a faster absorption time to peak value and lower blood concentration than those of capsules. Among the significant correlations observed, AUC_0-4 and C_1.5 showed the strongest significant correlation coefficient (r = 0.93, P < 0.001).

CONCLUSION

In pediatric NS, CsA metabolism may be faster than that in previous organ transplantation. Compared with C₂, C_1.5 monitoring may result in better disease control as it can best reflect the AUC_0-4 and peak values associated with side effects, which are indicators of therapeutic efficacy.