Intravenous cyclophosphamide in steroid-resistant nephrotic syndrome

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Intravenous cyclophosphamide induces remission in children with difficult to treat steroid resistant nephrotic syndrome from minimal change disease

BACKGROUND

Steroid resistant nephrotic syndrome (SRNS), while uncommon in children, is associated with significant morbidity. Calcineurin inhibitors (CNIs) remain the first line recommended therapy for children with non-genetic forms of SRNS, but some children fail to respond to them. Intravenous (IV) cyclophosphamide (CTX) has been shown to be effective in Asian-Indian children with difficult to treat SRNS (SRNS-DTT). Our study evaluated the outcome of IV CTX treatment in North American children with SRNS-DTT.

METHODS

Retrospective review of the medical records of children with SRNS-DTT treated with IV CTX from January 2000 to July 2019 at our center. Data abstracted included demographics, histopathology on renal biopsy, prior and concomitant use of other immunosuppressive agents and serial clinical/laboratory data. Primary outcome measure was attainment of complete remission (CR).

RESULTS

Eight children with SRNS-DTT received monthly doses (median 6; range 4-6) of IV CTX. Four (50%) went into CR, 1 achieved partial remission and 3 did not respond. Three of the 4 responders had minimal change disease (MCD). Excluding the 1 child who responded after the 4th infusion, the median time to CR was 6.5 (range 0.5-8) months after completion of IV CTX infusions. Three remain in CR at a median of 8.5 years (range: 3.7-10.5 years) after completion of CTX; one child relapsed and became steroid-dependent. No infections or life-threatening complications related to IV CTX were observed.

CONCLUSIONS

IV CXT can induce long term remission in North-American children with MCD who have SRNS-DTT.

Thrombotic microangiopathy triggered by podocytopathy

Thrombotic microangiopathy (TMA) is a rare group of diseases characterized by microangiopathic hemolytic anemia, thrombocytopenia, and target organ damage. It can be divided into primary and secondary TMA. Herein we report a case of TMA associated to a primary glomerular disease. We report the case of a 31-year-old Black male from Cape Verde admitted in March 2018 with nephrotic syndrome and upper gastrointestinal bleeding, the latter due to severe erythematous gastritis. He was discharged after clinical stabilization. The patient came to Portugal 8 months later. On admission, he presented with rapid deterioration of kidney function and hyperkalemia. The etiologic study revealed microangiopathic hemolytic anemia, nephrotic syndrome and microscopic hematuria. Immunologic study and viral serology were negative. ADAMTS13 activity and inhibitor testing were within normal range, genetic complement evaluation showed CFH-H3 in homozygosity, functional complement studies revealed decreased function of alternative pathway. Kidney biopsy was consistent with the diagnosis of TMA, and electron microscopy was compatible with minimal change disease. Patient underwent plasmapheresis with resolution of hemolysis, fluid overload and recovery of renal function. Two months later, he presented with nephrotic syndrome and started prednisolone with remission. Six months later, the nephrotic syndrome relapsed, and it became steroid-, MMF-, and rituximab-resistant. Tacrolimus was initiated, achieving partial remission. Atypical hemolytic uremic syndrome is an uncommon disease and is rarely reported as secondary to glomerular diseases. This case showcases the challenges regarding treatment options in a resistant glomerulopathy and the implications of therapeutic choices and kidney outcomes with the coexisting TMA.

Current understandings in treating children with steroid-resistant nephrotic syndrome

Steroid-resistant nephrotic syndrome (SRNS) remains a challenge for paediatric nephrologists. SRNS is viewed as a heterogeneous disease entity including immune-based and monogenic aetiologies. Because SRNS is rare, treatment strategies are individualized and vary among centres of expertise. Calcineurin inhibitors (CNI) have been effectively used to induce remission in patients with immune-based SRNS; however, there is still no consensus on treating children who become either CNI-dependent or CNI-resistant. Rituximab is a steroid-sparing agent for patients with steroid-sensitive nephrotic syndrome, but its efficacy in SRNS is controversial. Recently, several novel monoclonal antibodies are emerging as treatment option, but their efficacy remains to be seen. Non-immune therapies, such as angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, have been proven efficacious in children with SRNS and are recommended as adjuvant agents. This review summarizes and discusses our current understandings in treating children with idiopathic SRNS.

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.

Management of steroid-resistant nephrotic syndrome in children and adolescents

More than 85% of children and adolescents (majority between 1-12 years old) with idiopathic nephrotic syndrome show complete remission of proteinuria following daily treatment with corticosteroids. Patients who do not show remission after 4 weeks' treatment with daily prednisolone are considered to have steroid-resistant nephrotic syndrome (SRNS). Renal histology in most patients shows presence of focal segmental glomerulosclerosis, minimal change disease, and (rarely) mesangioproliferative glomerulonephritis. A third of patients with SRNS show mutations in one of the key podocyte genes. The remaining cases of SRNS are probably caused by an undefined circulating factor. Treatment with calcineurin inhibitors (ciclosporin and tacrolimus) is the standard of care for patients with non-genetic SRNS, and approximately 70% of patients achieve a complete or partial remission and show satisfactory long-term outcome. Additional treatment with drugs that inhibit the renin-angiotensin axis is recommended for hypertension and for reducing remaining proteinuria. Patients with SRNS who do not respond to treatment with calcineurin inhibitors or other immunosuppressive drugs can show declining kidney function and are at risk for end-stage renal failure. Approximately a third of those who undergo renal transplantation show recurrent focal segmental glomerulosclerosis in the allograft and often respond to combined treatment with plasma exchange, rituximab, and intensified immunosuppression.

Exploring the Clinical and Genetic Spectrum of Steroid Resistant Nephrotic Syndrome: The PodoNet Registry

Background: Steroid resistant nephrotic syndrome (SRNS) is a rare condition, accounting for 10-15% of all children with idiopathic nephrotic syndrome. SRNS can be caused by genetic abnormalities or immune system dysfunction. The prognosis of SRNS varies from permanent remission to progression to end-stage kidney disease, and post-transplant recurrence is common. Objectives: The PodoNet registry project aims to explore the demographics and phenotypes of immune-mediated and genetic forms of childhood SRNS, to assess genotype-phenotype correlations, to evaluate clinical management and long-term outcomes, and to search for novel genetic entities and diagnostic and prognostic biomarkers in SRNS. Methods: In 2009, an international registry for SRNS was established to collect retro- and prospective information on renal and extrarenal disease manifestations, histopathological and genetic findings and information on family history, pharmacotherapy responsiveness and long-term outcomes. To date, more than 2,000 patients have been enrolled at 72 pediatric nephrology centers, constituting the largest pediatric SRNS cohort assembled to date. Results: In the course of the project, traditional Sanger sequencing was replaced by NGS-based gene panel screening covering over 30 podocyte-related genes complemented by whole exome sequencing. These approaches allowed to establish genetic diagnoses in 24% of the patients screened, widened the spectrum of genetic disease entities presenting with SRNS phenotype (COL4A3-5, CLCN5), and contributed to the discovery of new disease causing genes (MYOE1, PTPRO). Forty two percent of patients responded to intensified immunosuppression with complete or partial remission of proteinuria, whereas 58% turned out multi-drug resistant. Medication responsiveness was highly predictive of a favorable long-term outcome, whereas the diagnosis of genetic disease was associated with a high risk to develop end-stage renal disease during childhood. Genetic SRNS forms were generally resistant to immunosuppressive treatment, justifying to avoid such pharmacotherapies altogether once a genetic diagnosis is established. Even symptomatic anti-proteinuric treatment with RAS antagonists seems to be challenging and of limited efficacy in genetic forms of SRNS. The risk of post-transplant disease recurrence was around 30% in non-genetic SRNS whereas it is negligible in genetic cases. Conclusion: In summary, the PodoNet Registry has collected detailed clinical and genetic information in a large SRNS cohort and continues to generate fundamental insights regarding demographic and etiological disease aspects, genotype-phenotype associations, the efficacy of therapeutic strategies, and long-term patient and renal outcomes including post-transplant disease recurrence.

Long-Term Outcome of Steroid-Resistant Nephrotic Syndrome in Children

We investigated the value of genetic, histopathologic, and early treatment response information in prognosing long-term renal outcome in children with primary steroid-resistant nephrotic syndrome. From the PodoNet Registry, we obtained longitudinal clinical information for 1354 patients (disease onset at >3 months and <20 years of age): 612 had documented responsiveness to intensified immunosuppression (IIS), 1155 had kidney biopsy results, and 212 had an established genetic diagnosis. We assessed risk factors for ESRD using multivariate Cox regression models. Complete and partial remission of proteinuria within 12 months of disease onset occurred in 24.5% and 16.5% of children, respectively, with the highest remission rates achieved with calcineurin inhibitor-based protocols. Ten-year ESRD-free survival rates were 43%, 94%, and 72% in children with IIS resistance, complete remission, and partial remission, respectively; 27% in children with a genetic diagnosis; and 79% and 52% in children with histopathologic findings of minimal change glomerulopathy and FSGS, respectively. Five-year ESRD-free survival rate was 21% for diffuse mesangial sclerosis. IIS responsiveness, presence of a genetic diagnosis, and FSGS or diffuse mesangial sclerosis on initial biopsy as well as age, serum albumin concentration, and CKD stage at onset affected ESRD risk. Our findings suggest that responsiveness to initial IIS and detection of a hereditary podocytopathy are prognostic indicators of favorable and poor long-term outcome, respectively, in children with steroid-resistant nephrotic syndrome. Children with multidrug-resistant sporadic disease show better renal survival than those with genetic disease. Furthermore, histopathologic findings may retain prognostic relevance when a genetic diagnosis is established.

A Randomized Controlled Trial of Intravenous versus Oral Cyclophosphamide in Steroid-resistant Nephrotic Syndrome in Children

This is a randomized, parallel group, active-controlled trial to compare the efficacy of intravenous cyclophosphamide (IVCP) with oral cyclophosphamide (OCP) in patients with steroid-resistant nephrotic syndrome (SRNS) in children. Fifty consecutive children with idiopathic SRNS were biopsied and then randomized to receive either OCP at a dose of 2 mg/kg/day for 12 weeks or IVCP at a dose of 500 mg/m²/month for 6 months. Both groups received tapering doses of oral steroids. The response was evaluated in terms of induction of complete remission (CR) or partial remission (PR), time to remit, and side effects. The groups were followed up to determine the duration of remission, percentage of patients who remain in sustained remission for more than 1 year after completion of therapy, change in steroid response status, progression to chronic kidney disease stage 3 or more. Of the fifty patients, OCP was given to 25 children and IVCP to 25 children. The demographic data, histopathology, biochemical profile, and duration of follow-up in the two groups were comparable. The rates of induction of CR were 52% versus 44% and of PR were 8% versus 8% in the intravenous (IV) and oral group, respectively. Time to remit was shorter with OCP than IVCP (53 days vs. 84.4 days). Incidence of side effects (both major and minor) was 36% in IVCP versus 20% in OCP group. The actuarial cumulative sustained remission in our study was 12% in IVCP compared with 16% in OCP at 1 year after completion of therapy. Twelve percent children in both the groups exhibited restoration of steroid sensitivity. Thus, in our study, overall, more than half of SRNS patients showed initial response to cyclophosphamide, but only one-fourth patients had sustained remission on follow-up. OCP and IVCP were equally efficacious and safe in idiopathic SRNS in children.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Immunosuppressive therapy in children with steroid-resistant, frequently-relapsing, and steroid-dependent idiopathic nephrotic syndrome: a single center experience

Introduction

Immunosuppressive agents are recommended for the management of children with steroid-resistant (SRNS), frequently-relapsing (FRNS), and steroid-dependent idiopathic nephrotic syndrome (SDNS). This study evaluated the efficacy of immunosuppressive agents in these cases.

Methods

This is a retrospective analysis of the records of 130 pediatric cases recruited from a tertiary-care center over a period of two years. They were divided into two groups: 51 patients with SRNS (Group I) and 79 cases with SDNS and FRNS (Group II). They were treated with immunosuppressive agents in addition to steroids, either as double- or triple-combination therapy. Complete or partial remission was considered a good response.

Results

In group I, the proportions of good response to cyclophosphamide, cyclosporine A, and mycophenolate mofetil were 48.6, 60, and 80%, respectively (p = 0.162). In group II, the resistance rate was significantly higher with levamisole than with cyclophosphamide and azathioprine (p = 0.046). Leukopenia was reported infrequently after the administration of cyclophosphamide or azathioprine. The most serious adverse reaction was to cyclosporine A, which induced nephrotoxicity (6.4%), while no adverse effects related to levamisole were reported. Histopathological diagnoses were available in only 39 patients.

Conclusion

The high potency of cyclosporine with steroids recommends its use in patients with idiopathic SRNS with a normal glomerular filtration rate. Its efficacy is augmented when combined with mycophenolate mofetil. Cyclophosphamide, orally or as intravenous boluses, together with alternate-day steroids, could be a good option outside the peripubertal age. The outcomes of FRNS and SDNS could be improved by encouraging compliance with the use of levamisole.

[Treatment of idiopathic nephrotic syndrome in children]

The annual incidence of the nephrotic syndrome has been estimated to be 1-3 per 100,000 children<16 year of age. In children, the most common cause of nephrotic syndrome is idiopathic nephrotic syndrome (INS). INS is defined by the presence of proteinuria and hypoalbuminemia and by definition is a primary disease. Renal biopsy study shows non-specific histological abnormalities of the kidney including minimal changes, focal and segmental glomerular sclerosis, and diffuse mesangial proliferation. Steroid therapy is applied in all cases of INS. Renal biopsy is usually not indicated before starting corticosteroid therapy. The majority of patients (80-90%) are steroid-responsive. Children with INS who do not achieve a complete remission with corticosteroid therapy commonly present focal and segmental glomerular sclerosis and require treatment with calcineurin inhibitors (cyclosporine or tacrolimus), mycophenolate mofetil or rituximab, plus renin-angiotensin system blockade. In this article we review the recent accepted recommendations for the treatment of children with INS.

A new 'tac' for childhood nephrotic syndrome

Calcineurin inhibitors (CNIs) are frequent first-line agents in children with steroid-resistant nephrotic syndrome (SRNS). However, limited randomized controlled trial (RCT) data are available comparing CNIs with alternative therapies. Gulati and colleagues report their experience with tacrolimus versus cyclophosphamide in childhood SRNS. Their results establish clear superiority of tacrolimus over cyclophosphamide and give further proof that RCTs in childhood SRNS are both feasible and vital for improving the standard of care.

Prospective 5-year follow-up of cyclosporine treatment in children with steroid-resistant nephrosis

BACKGROUND

Cyclosporine has improved remission rates in children with steroid-resistant nephrotic syndrome (SRNS). However, little prospective long-term follow-up data is available.

METHODS

We prospectively followed and analyzed 5-year outcomes of all 35 patients enrolled in our previous prospective multicenter trial with cyclosporine and steroids in children with SRNS. At enrollment, 23 cases were classified as minimal change (MC), five as diffuse mesangial proliferation (DMP), and seven as focal segmental glomerulosclerosis (FSGS).

RESULTS

Renal survival at 5 years (median 7.7 years) was 94.3 %. Patient status was complete remission (CR) in 31 (88.6 %) (MC/DMP, 25; FSGS, 6); partial remission in one (FSGS); and non-remission in three (MC/DMP), including chronic kidney disease and end-stage kidney disease in one each. Among 31 patients with CR, 22 (71.0 %) were receiving treatment with immunosuppressants at 5 years, including cyclosporine in 19, and seven of these 22 continued to show frequent relapse. Response to cyclosporine at 4 months predicted 5-year outcome in 31 of 35 patients.

CONCLUSIONS

Although SRNS treatment with cyclosporine provides high renal survival and remission rates, many children require ongoing immunosuppression. Management has advanced from the prevention of end-stage kidney disease to the long-term maintenance of remission and management of relapse after induction therapy.

Calcineurin inhibitor induced nephrotoxicity in steroid resistant nephrotic syndrome

Prolonged therapy with calcineurin inhibitors (CNI) is effective in patients with difficult nephrotic syndrome. However, information on prevalence and risk factors for nephrotoxicity in children with steroid-resistant nephrotic syndrome is limited. This retrospective observational study was conducted on 40 patients with steroid-resistant nephrotic syndrome treated with cyclosporine (CyA) (n = 28) or tacrolimus (n = 12) for more than 2 years. Nephrotoxicity was defined by the presence of striped fibrosis involving ≥10% of the interstitium or nodular hyalinosis in more than one arteriole. Ten additional parameters were graded semi-quantitatively. Continuous data are presented as median and interquartile range (IQR). The median (IQR) age at onset of nephrotic syndrome and CNI therapy were 30 (21-45) and 49.5 (40-102.5) months. A second renal biopsy, following 30 (26-35) months of CNI therapy, showed histological toxicity in 10 (25%) patients. Toxicity was seen in 7 and 3 patients receiving CyA and tacrolimus, respectively, and 5 patients each with minimal change and focal segmental glomerulosclerosis. Therapy with CNI was associated with significant increases in scores for global glomerulosclerosis, tubular atrophy, interstitial fibrosis, nonnodular arteriolar hyalinosis (P < –0.001 for all), arteriolar smooth-muscle vacuolization (P = –0.02), juxtaglomerular hyperplasia (P = –0.002), and tubular microcalcinosis (P = –0.06). Risk factors for nephrotoxicity were initial resistance (OR 9; 95% CI 1.0-80.1; P = –0.049); dose of CyA (OR 9.2; 95% CI 1.1-74.6; P = –0.037); duration of heavy proteinuria (OR 1.2; 95% CI 1.0-1.4; P = –0.023); and hypertension during therapy (OR 6; 95% CI 1.3-28.3; P = –0.023). Following prolonged CNI therapy, one in four biopsies show features of toxicity. Prolonged duration of heavy proteinuria, hypertension, initial steroid resistance and high CyA dose predict the occurrence of nephrotoxicity.

The treatment of minimal change disease in adults

Minimal change disease (MCD) is the etiology of 10%-25% of cases of nephrotic syndrome in adults. The mainstay of treatment for adult MCD, oral glucocorticoids, is based on two randomized controlled trials and extensive observational data in adults, and this treatment leads to remission in over 80% of cases. Relapses are common, and some patients become steroid-resistant (SR), steroid-dependent (SD), or frequently relapsing (FR). The data guiding the treatment of these patients are limited. Here, we review MCD in adults with particular focus on the evidence for immunosuppressive therapy in these patients.

Treatment with tacrolimus and prednisolone is preferable to intravenous cyclophosphamide as the initial therapy for children with steroid-resistant nephrotic syndrome

There are limited data on the relative efficacy and safety of calcineurin inhibitors and alkylating agents for idiopathic steroid-resistant nephrotic syndrome in children. To clarify this, we compared tacrolimus and intravenous cyclophosphamide therapy in a multicenter, randomized, controlled trial of 131 consecutive pediatric patients with minimal change disease, focal segmental glomerulosclerosis, or mesangioproliferative glomerulonephritis, stratified for initial or late steroid resistance. Patients were randomized to receive tacrolimus for 12 months or 6-monthly infusions of intravenous cyclophosphamide with both arms receiving equal amounts of alternate-day prednisolone. The primary outcome of complete or partial remission at 6 months, based on spot urine protein to creatinine ratios, was significantly higher in children receiving tacrolimus compared to cyclophosphamide (hazard ratio 2.64). Complete remission was significantly higher with tacrolimus (52.4%) than with cyclophosphamide (14.8%). The secondary outcome of sustained remission or steroid-sensitive relapse of nephrotic syndrome at 12 months was significantly higher with tacrolimus than cyclophosphamide. Treatment withdrawal was higher with cyclophosphamide, chiefly due to systemic infections. Compared to cyclophosphamide, 3 patients required treatment with tacrolimus to achieve 1 additional remission. Thus, tacrolimus and prednisolone are effective, safe, and preferable to cyclophosphamide as the initial therapy for patients with steroid-resistant nephrotic syndrome.

Long-term outcome of idiopathic steroid-resistant nephrotic syndrome: a multicenter study

Long-term outcome of idiopathic steroid-resistant nephrotic syndrome was retrospectively studied in 78 children in eight centers for the past 20 years. Median age at onset was 4.4 years (1.1-15.0 years) and the gender ratio was 1.4. Median follow-up period was 7.7 years (1.0-19.7 years). The disease in 45 patients (58%) was initially not steroid-responsive and in 33 (42%) it was later non-responsive. The main therapeutic strategies included administration of ciclosporine (CsA) alone (n = 29; 37%) and CsA + mycophenolate mofetil (n = 18; 23%). Actuarial patient survival rate after 15 years was 97%. Renal survival rate after 5 years, 10 years and 15 years was 75%, 58% and 53%, respectively. An age at onset of nephrotic syndrome (NS) > 10 years was the only independent predictor of end-stage renal disease (ESRD) in a multivariate analysis using a Cox regression model (P < 0.001). Twenty patients (26%) received transplants; ten showed recurrence of the NS: seven within 2 days, one within 2 weeks, and two within 3-5 months. Seven patients lost their grafts, four from recurrence. Owing to better management, kidney survival in idiopathic steroid-resistant nephrotic syndrome (SRNS) has improved during the past 20 years. Further prospective controlled trials will delineate the potential benefit of new immunosuppressive treatment.

Tacrolimus therapy in adults with steroid- and cyclophosphamide-resistant nephrotic syndrome and normal or mildly reduced GFR

BACKGROUND

In a proportion of adults with steroid-resistant nephrotic syndrome (SRNS), intravenous cyclophosphamide therapy fails. Tacrolimus may be a promising alternative to cyclophosphamide for such patients.

STUDY DESIGN

Prospective observational study.

SETTING & PARTICIPANTS

19 adults with SRNS (6 with minimal change nephropathy, 8 with focal segmental glomerulosclerosis [FSGS], and 5 with mesangioproliferative glomerulonephritis) that did not respond to intravenous cyclophosphamide therapy were studied from January 2003 to September 2006. Oral tacrolimus was administered (target trough levels, 5 to 10 ng/mL) for 24 weeks, then reduced doses were given (target trough level, 3 to 6 ng/mL) for another 24 weeks.

FACTORS

Histopathologic types: minimal change nephropathy (n = 6), FSGS (n = 8), and mesangioproliferative glomerulonephritis (n = 5).

OUTCOMES

MEASUREMENTS

outcome variables included complete remission (decrease in daily proteinuria to protein < or = 0.3 g/d), partial remission (decrease in daily proteinuria to protein < 3.5 g/d but > 0.3 g/d), relapse (increase in daily proteinuria to protein > or = 3.5 g/d in patients who had partial or complete remission), change in kidney function, and tacrolimus dosing and serum levels.

RESULTS

17 patients completed at least 24 weeks of tacrolimus therapy. Complete remission was achieved in 11 patients (64.7%), and partial remission was achieved in 3 (17.6%). Complete or partial remission was achieved in 5 of 5 patients with minimal change nephropathy, 4 of 7 patients with FSGS, and 5 of 5 patients with mesangioproliferative glomerulonephritis. Primary resistance to tacrolimus was seen in 3 patients (17.6%), all with FSGS. Mean times to achieve partial and complete remission were 5.6 +/- 1.4 and 8.0 +/- 5.1 weeks, respectively. In patients who achieved complete or partial remission, 35.7% experienced relapse during follow-up (mean, 37.6 +/- 13.4 months). Two patients had doubling of serum creatinine levels, both with FSGS.

LIMITATIONS

Observational study.

CONCLUSIONS

Tacrolimus rapidly and effectively induced remission of SRNS in Chinese adults with disease refractory to treatment with intravenous cyclophosphamide. Treatment may be less effective in patients with FSGS.

Efficacy and safety of tacrolimus versus cyclosporine in children with steroid-resistant nephrotic syndrome: a randomized controlled trial

BACKGROUND

To examine whether tacrolimus is more effective and safe than cyclosporine (CsA) in inducing remission in patients with steroid-resistant nephrotic syndrome (SRNS).

STUDY DESIGN

Randomized controlled trial, nonblind, parallel group.

SETTINGS & PARTICIPANTS

Tertiary-care hospital; 41 consecutive patients with idiopathic SRNS, estimated glomerular filtration rate greater than 60 mL/min/1.73 m(2), and histological characteristics showing minimal change disease, focal segmental glomerulosclerosis, or mesangioproliferative glomerulonephritis were randomly assigned to treatment with tacrolimus (n = 21) or CsA (n = 20).

INTERVENTION

Tacrolimus (0.1 to 0.2 mg/kg/d) or CsA (5 to 6 mg/kg/d) for 1 year; cotreatment with alternate-day prednisolone and enalapril.

OUTCOMES

Patients achieving complete remission (urinary protein-creatinine ratio < 0.2 g/g and serum albumin > or = 2.5 g/dL) or partial remission (urinary protein-creatinine ratio, 0.2 to 2 g/g, and serum albumin > or =2.5 g/dL) at 6 and 12 months; time to remission; proportion with relapses; side effects.

RESULTS

No patient was lost to follow-up. After 6 months of therapy, remission occurred in 18 (85.7%) and 16 patients (80%) treated with tacrolimus and CsA, respectively (relative risk [RR], 1.07; 95% confidence interval [CI], 0.81 to 1.41). Rates of remission at 12 months were also similar (RR, 1.14; 95% CI, 0.84 to 1.55). The proportion of patients who experienced relapse was significantly greater in those receiving CsA compared with tacrolimus (RR, 4.5; 95% CI, 1.1 to 18.2; P = 0.01). The decrease in blood cholesterol levels was greater with tacrolimus compared with CsA (difference in mean values, 45.1 mg/dL; 95% CI, 19.1 to 71.2). Persistent nephrotoxicity necessitating stoppage of medicine was seen in 4.7% and 10% patients, respectively. Cosmetic side effects (hypertrichosis and gum hypertrophy) were significantly more frequent in CsA-treated patients (P < 0.001).

LIMITATIONS

Single-center study, small sample size, and short duration of follow-up.

CONCLUSIONS

Tacrolimus or CsA in combination with low-dose steroids show similar efficacy in inducing remission in patients with SRNS. Therapy with tacrolimus is a promising alternative to CsA in view of the lower risk of relapses and lack of cosmetic side effects.

Experience with tacrolimus in children with steroid-resistant nephrotic syndrome

Children with steroid-resistant nephrotic syndrome (SRNS) are at risk of developing renal failure. We report here the results of a single-center retrospective observational study of the remission rate in pediatric patients with SNRS receiving tacrolimus. Serial renal biopsies from children on tacrolimus therapy were evaluated for tubulointerstitial fibrosis and transforming growth factor-beta immunostaining. Of the 16 children with SRNS, 15 went into complete remission after a median of 120 days of therapy. Nine children were able to stop steroids, while the others were on tapering doses. Forty-seven percent had relapses, most of which were steroid-responsive. Serial renal biopsies were obtained from seven children after a median treatment duration of 24 months; two of these children had increased tubulointerstitial fibrosis and four showed increased transforming growth factor-beta tissue staining. Children with worsening histological findings were younger. There was no significant association between tacrolimus exposure and biopsy changes, although the average trough level was higher in those children with worsening histological findings. In conclusion, tacrolimus may be a safe and effective alternative agent for inducing remission in children with SRNS. However, caution needs to be taken when prescribing this agent due to its narrow therapeutic index. Serial renal biopsies are necessary to check for subclinical nephrotoxicity, especially in younger children and those with higher trough levels.

Therapies for steroid-resistant nephrotic syndrome

Between 10 and 20% of children with primary nephrotic syndrome are steroid-resistant (SRNS). From earlier studies in children with SRNS, we know that cyclosporin (with or without alternate-day prednisone) and cyclophosphamide (with pulse intravenous corticosteroids) result in comparable complete or partial remission rates of about 60%. An evaluation of the relative effectiveness of cyclophosphamide and cyclosporin has not been possible because of the absence of a head-to-head randomised trial. The Arbeitsgemeinschaft für Pädiatrische Nephrologie trial, published in this issue of Pediatric Nephrology, has filled this gap in our evidence base. Although there was no difference in the number of patients achieving complete remission, those patients receiving cyclosporin treatment were significantly more likely to achieve partial remission than those receiving intravenous cyclophosphamide. This result suggests that cyclosporin rather than cyclophosphamide should be used as first line therapy for children with SRNS.

Efficacy of intravenous pulse cyclophosphamide treatment versus combination of intravenous dexamethasone and oral cyclophosphamide treatment in steroid-resistant nephrotic syndrome

We compared, in a randomized controlled trial, the efficacy of a regimen based on intravenous (i.v.) cyclophosphamide therapy with a combination of i.v. dexamethasone and oral cyclophosphamide therapy in inducing remission in patients with steroid-resistant nephrotic syndrome (SRNS). During April 2001 to December 2003, 52 consecutive patients with idiopathic SRNS, normal renal function and renal histology findings showing minimal change disease, focal segmental glomerulosclerosis or mesangioproliferative glomerulonephritis were enrolled into the study. Patients in group I received i.v. injection of cyclophosphamide once a month for 6 months and prednisolone on alternate days. Those in group II received i.v. treatment with dexamethasone (initially on alternate days, later fortnightly and monthly; total 14 doses), oral cyclophosphamide therapy (for 3 months) and prednisolone on alternate days. Data from 49 patients (26 in group I, 23 in group II) were analyzed; their clinical and biochemical features were similar at inclusion. Following treatment, complete remission was seen in 53.8% and 47.8% patients in groups I and II, respectively (P = 0.6). Long-term follow up showed favorable outcome in 14 (53.8%) patients in group I, and 9 (39.1%) in group II. Chief adverse effects, including cushingoid features and serious infections, were similar in both groups. Patients receiving i.v. dexamethasone therapy commonly showed hypertension and hypokalemia, while vomiting and reversible alopecia occurred in those receiving i.v. treatment with cyclophosphamide. In patients with SRNS, the efficacy of treatment intravenously with cyclophosphamide and orally with prednisolone was similar to the combination of dexamethasone intravenously, orally administered cyclophosphamide and prednisolone.

Cyclosporin A is superior to cyclophosphamide in children with steroid-resistant nephrotic syndrome-a randomized controlled multicentre trial by the Arbeitsgemeinschaft für Pädiatrische Nephrologie

First line immunosuppressive treatment in steroid-resistant nephrotic syndrome in children is still open to discussion. We conducted a controlled multicentre randomized open label trial to test the efficacy and safety of cyclosporin A (CSA) versus cyclophosphamide pulses (CPH) in the initial therapy of children with newly diagnosed primary steroid-resistant nephrotic syndrome and histologically proven minimal change disease, focal segmental glomerulosclerosis or mesangial hypercellularity. Patients in the CSA group (n = 15) were initially treated with 150 mg/m(2) CSA orally to achieve trough levels of 120-180 ng/ml, while patients in the CPH group (n = 17) received CPH pulses (500 mg/m(2) per month intravenous). All patients were on alternate prednisone therapy. Patients with proteinuria >40 mg/m(2) per hour at 12 weeks of therapy were allocated to a non-responder protocol with high-dose CSA therapy or methylprednisolone pulses. At week 12, nine of the 15 (60%) CSA patients showed at least partial remission, evidences by a reduction of proteinuria <40 mg/h per m(2). In contrast, three of the 17 (17%) CPH patients responded (p < 0.05, intention-to-treat). Given these results, the study was stopped, in accordance with the protocol. After 24 weeks, complete remission was reached by two of the 15 (13%) CSA and one of the 17 (5%) CPH patients (p = n.s.). Partial remission was achieved by seven of the 15 (46%) CSA and two of the 15 (11%) CPH patients (p <0.05). Five patients in the CSA group and 14 patients in the CPH group were withdrawn from the study, most of them during the non-responder protocol. The number of adverse events was comparable between both groups. We conclude that CSA is more effective than CPH in inducing at least partial remission in steroid-resistant nephrotic syndrome in children.

Corticosteroid-resistant nephrotic syndrome with focal and segmental glomerulosclerosis : an update of treatment options for children

Corticosteroid-resistant nephrotic syndrome (CRNS) with focal and segmental glomerulosclerosis (FSGS) is a heterogeneous disorder and the most severe and frequent type of all glomerulopathies in children leading to end-stage renal failure. The podocyte is at the center of development and progress of FSGS; this unique cell type plays a major role in the integrity of glomerular structure and permeability. The rate of complete remission of CRNS after induction therapy using different immunosuppressant agents is reported to range between 30% and 84%, depending on the treatment schedule and on the underlying defects of FSGS. Children with genetic types of FSGS barely respond to immunosuppressant therapies and over-treatment prior to transplantation should be avoided. The response of children with an idiopathic type of FSGS to immunosuppressants is superior to those with genetic FSGS. However, many children with idiopathic FSGS do not enter complete remission if they are under-treated, for example, with short-term immunosuppressant monotherapies. If immunosuppressant treatment fails, these patients will have to undergo renal transplantation. However, as unknown pathogenetic mechanisms may persist, more than one-third of these patients with idiopathic FSGS develop a rapid recurrence of CRNS that responds poorly to further long-term therapeutic attempts. In contrast with previously published data, this review takes into account recently identified genetic etiologies of CRNS, and superior results with long-term combination therapy in idiopathic forms to avoid over- and under-treatment.

Clinical course and NPHS2 analysis in patients with late steroid-resistant nephrotic syndrome

A small fraction of patients with initial steroid-sensitive nephrotic syndrome (SSNS) develops late steroid resistance, i.e. a lack of remission after 4 weeks of relapse treatment despite previous response to steroids. The pathophysiological basis of late resistance and the long-term prognosis remain obscure. Fourteen out of 360 patients with SSNS who were seen in our department between 1954 and 2005 developed late resistance. Median age at onset of NS was 4 years and median duration of development of late resistance 4.6 months. Histology showed minimal-change (MC) nephropathy in six patients and focal segmental glomerulosclerosis (FSGS) in three patients on initial biopsy and four patients on repeat biopsies. Late resistance was treated with cyclophosphamide in five patients, cyclosporine A in three, and both drugs in one. Eight of these nine patients went into remission. All 14 patients maintained a stable kidney function during their period of observation. NPHS2 mutation analysis in eight patients revealed no pathogenic mutations, suggesting that late resistance is not typically associated with mutations in the NPHS2 gene. With respect to the clinical course, late resistance appears to resemble SSNS and is characterized by a favorable outcome.

Steroid-resistant nephrotic syndrome: long-term evolution after sequential therapy

We present a retrospective study of 30 children of mean age 3.02 +/- 1.81 years with steroid-resistant nephrotic syndrome (SRNS) treated with intravenous injection of methylprednisolone plus orally administered prednisone; 24 children also received cyclophosphamide (CP). Sixteen were resistant to steroids from the beginning, and 14 after a mean of 11.26 +/- 16.61 months. The initial histological diagnosis was: 18 minimal change disease (MCD), 11 focal segmental glomerulosclerosis (FSGS) and one diffuse mesangial proliferative glomerulonephritis (DMPG). Total remission was achieved in 22 patients (73.3%), partial response in three (10%) and no response in five (16.6%), two of whom were brothers carrying an NPHS2 gene double mutation. There was no difference in response between the MCD and FSGS patients; the only patient with DMPG did not respond. Only initial resistance was a sign of bad prognosis. At follow-up (6.4 +/- 3.6 years from last pulse), 21/22 were still in remission, 14/21 were without treatment. Six patients required cyclosporine or mycophenolate mofetil because of steroid dependence. Two non-responders developed end-stage renal failure (ESRF); the remaining patients maintained normal glomerular filtration. The treatment was well tolerated. In conclusion, most of the patients treated with sequential therapy consisting of methylprednisolone (MP) (100%) and CP (80%) showed remission and preserved renal function, but 20% developed steroid dependence.

Alkylating drugs applied in non-cytotoxic doses as a novel compounds targeting inflammatory signal pathway

Alkylating drugs (ADs) belonging to the nitrogen mustard family are commonly used as cytostatic and immunosuppressive agents. Our previous in vitro studies demonstrated that in the case of gradual dose decrease, the number of targets for alkylation in the cell is also reduced and the drug switches from brutal cytostatic to cell growth modifier. At doses of 0.3 microg/ml and lower, the effects of ADs are no longer associated with DNA damage or stress/MAPK pathways activation. Instead, the disruption of signal transduction by the IL-2beta and/or TNFalpha cell surface receptors is observed. As a result, ADs in the doses 100-fold lower than cytostatic ones are capable to modify lymphocyte activity including the activity of regulatory T cells. We hypothesized that ADs may have a beneficial effect in the treatment of inflammatory diseases. Indeed, the application of non-cytotoxic doses of an AD melphalan reduces the severity of murine experimental colitis. Daily administration of melphalan (25 microg/kg body weight) markedly reduced the severity of DSS-colitis as determined by clinical and histological criteria. Moreover, the beneficial effect of melphalan was also shown in asthmatic patients. In 60% of these patients histological and ultrastructural signs of bronchial epithelium regeneration were also revealed. Thus, ADs at non-cytotoxic concentrations exert beneficial effect both in acute and chronic inflammatory diseases. Such anti-inflammatory activity is thought to be due to blocking of signal transduction through various cell surface receptor including IL-2R and TNFR. Consequently different steps of inflammatory cascade turn out to be inhibited.

Herbs or natural substances as complementary therapies for chronic kidney disease: ideas for future studies

Chronic kidney disease (CKD) is an increasingly common condition with limited treatment options that is placing a major financial and emotional burden on the community. The use of complementary and alternative medicines (CAMS) has increased many-fold over the past decade. Although several compelling studies show renal toxicities and an adverse outcome from use of some CAMS, there is also emerging evidence in the literature that some may be renoprotective. Many nephrologists are unaware of these potential therapeutic benefits in treating CKD, or they are reluctant to consider them in research trials for fear of adverse effects (including nephrotoxicity) or deleterious interaction with co-prescribed, conventional medicines. The increased use of self-prescribed CAMS by their patients suggests that practitioners and researchers should keep abreast of the current information on these agents. A primary goal of this article was to review the available scientific evidence for the use of herbs or natural substances as a complementary treatment for patients with CKD. A further goal was to report the literature on herbs that have been reported to cause kidney failure.

Mycophenolate mofetil therapy in frequently relapsing steroid-dependent and steroid-resistant nephrotic syndrome of childhood: current status and future directions

Clinicians are often faced with therapeutic dilemmas and challenges while treating children with frequently relapsing steroid-dependent nephrotic syndrome (SDNS) and steroid-resistant nephrotic syndrome (SRNS). In the past, children with SDNS have been treated with long-term alternate day steroids cyclophosphamide, cyclosporine (CSA), chlorambucil, levamisole, and azathioprine. The essential aim of these therapies is to maintain remission while limiting exposure to steroids. These medications have variable efficacy and undesirable toxicity profiles. Recently, mycophenolate mofetil (MMF) has emerged as a new therapeutic option for the management of SDNS in a few uncontrolled clinical trials. Preliminary data are encouraging. MMF was found to be useful in maintaining remission and has a steroid-sparing effect. Clearly, more data are needed to further characterize the safety and efficacy of MMF, define adequate length of treatment, and optimize drug exposure and monitoring. The management of SRNS is primarily aimed at decreasing proteinuria and inducing remission, if possible. By doing so, one would aim to preserve renal function. CSA therapy is known to be useful in this regard but has undesirable side effects, the most concerning being nephrotoxicity. MMF in combination with steroids and angiotensin-converting enzyme-inhibitor drugs is known to have some efficacy in the management of SRNS. These preliminary data have prompted the National Institutes of Health to sponsor a multicentric controlled trial to compare the safety and efficacy of MMF with that of CSA in the treatment of steroid-resistant focal segmental glomerulosclerosis (FSGS). If MMF therapy is found to be efficacious, it would help obviate the need for CSA and its associated nephrotoxicity. Clearly, MMF has emerged as an important new therapeutic option for the treatment of childhood nephrotic syndrome and FSGS. Further data are required to assess those conditions most likely to respond.

Mycophenolate mofetil in steroid/cyclosporine-dependent/resistant nephrotic syndrome

Attempts to minimize the effects of prolonged steroid use in steroid-dependent nephrotic syndrome (SDNS) and the need to overcome steroid resistance (SRNS) justifies immunosuppressant therapy. We report our experience in a cohort of patients with SD/SRNS during the administration of mycophenolate mofetil (MMF) in a prospective protocol initiated in January 2001. Twenty-six children with idiopathic nephrotic syndrome were included (21 steroid dependent and 5 steroid resistant), whose response did not change after sequential treatment with cyclophosphamide (CPM) and cyclosporine (CsA). Histopathologic patterns were: 11 minimal change disease (MCD), 1 diffuse mesangial proliferation (DMP), 13 focal segmental glomerulosclerosis (FSGS) and membranous 1 glomerulonephritis (MGN). The median age of onset of NS was 2.8 years (range 1.2-12.5), and treatment with MMF was performed at a median age of 11.4 years (range 5-17) with an initial dose of 600 mg/m(2)/12 h, adjusted to maintain levels of mycophenolic acid (MPA) at 2.5-5 mcg/ml. The planned duration of study to assess treatment efficacy was 6 months. The mean MMF dose required was 624 (SD=136) mg/m(2)/12 h (range 415-970), which maintained mean C(0)-MPA levels of 2.9 (SD=1.17) mcg/ml (range 1.2-5.9 mcg/ml). In the five patients with SRNS, only one achieved complete remission. In the patients with SDNS, steroid sparing was achieved in 15 and 9 remained in remission on MMF monotherapy. Withdrawal of MMF resulted in immediate relapse in 47%. In our study, MMF was a useful immunosuppressant due to its fewer undesirable effects and similar efficacy to other drugs used. It appears effective for the maintenance of remission in SDNS patients, with a response similar to that of CsA.

Efficacy of methylprednisolone pulse therapy in steroid-resistant nephrotic syndrome

Steroid-resistant nephrotic syndrome (SRNS) in children is intractable, and the optimal treatment regimen is not known. We investigated the efficacy of methylprednisolone pulse therapy (MPT) in SRNS patients. Using only MPT plus heparin, we have treated ten pediatric SRNS patients that were resistant to cyclophosphamide (CPM) or cyclosporin A (CsA) and predicted to have a very poor prognosis. Administration of 30 mg/kg per day methylprednisolone with heparin for 3 days was taken as one course, and this was given 14 times over 2 years. One patient discontinued MPT because of peritonitis. Of the remaining nine patients, complete remission was achieved by four patients, persistent mild proteinuria remained in three patients, and no effect was observed in two patients. All patients that had been diagnosed with minimal change (MC) pathology ( n=3) at the initial renal biopsy achieved complete remission. Observed adverse events were peritonitis in one patient and a transient decrease in pulse rate only during MPT in one patient. These results demonstrate that MPT with heparin can induce remission in children with SRNS, even when the patient is resistant to CPM and CsA.

Intravenous pulse cyclophosphamide--is it effective in children with steroid-resistant nephrotic syndrome?

Treatment of steroid-resistant nephrotic syndrome (SRNS) remains a challenge to pediatric nephrologists. Recently, intravenous cyclophosphamide (IV-CPM) infusion was shown to be effective, safe, and economical for the treatment of SRNS, particularly minimal change disease (MCD), as it results in more sustained remissions, longer periods without proteinuria, and fewer significant side effects at a lower cumulative dose. A prospective study was conducted to evaluate IV-CPM infusions in the management of children with SRNS secondary to MCD or IgM nephropathy. Five patients with SRNS (4 IgM nephropathy and 1 MCD) received six monthly IV-CPM infusions at a dose of 500 mg/m(2). No patient achieved complete or sustained remission. Three patients attained partial remission, which was not sustained for more than 1 month post therapy. One patient progressed rapidly to end-stage renal disease during treatment. Side effects included vomiting in four patients and alopecia in one patient.

CONCLUSION

IV-CPM pulse therapy at a dose of 500 mg/m(2) is unsuccessful in obtaining complete or sustained remission in children with SRNS secondary to IGM nephropathy or MCD. Further randomized controlled studies with higher doses are required.