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

Cyclophosphamide versus cyclosporine A therapy in steroid-resistant nephrotic syndrome: a retrospective study with a mean 5-year follow-up

Objective

To compare the clinical efficacy of cyclophosphamide (CTX) and cyclosporine A (CSA) in initial treatment of children with steroid-resistant nephrotic syndrome (SRNS).

Methods

Prospectively maintained databases were reviewed to retrospectively compare two cohorts with SRNS that received peroral administration of 2 to 2.5 mg/kg/d CTX for 3 to 6 months or 1 to 5 mg/kg/d CSA for 2 years until the primary analysis cut-off date during 2007 to 2011. The time to first on-study relapse of SRNS was the primary endpoint. The effective rate was the second endpoint.

Results

A total of 127 children with SRNS were included (CTX-treated cohort: n = 62; CSA-treated cohort: n = 65), with a mean 5-year follow-up. CTX-treated children showed a significantly delayed time to first on-study relapse of SRNS compared with CSA-treated children (hazard ratio 0.66, 95% confidence interval 0.32–1.75). The relapse rate (rate/year) in CTX-treated children (1.1 ± 0.1) at the 24-month follow-up was significantly higher than that with CSA (0.4 ± 0.2). This difference persisted until the final follow-up.

Conclusions

CSA is associated with a significantly lower relapse rate and significantly higher effective rate compared with CTX, especially in children with minimal change disease.

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.

Second-line options for refractory steroid-sensitive and -resistant nephrotic syndrome

Although initially, many children with idiopathic nephrotic syndrome respond to steroid therapy, a repeated course for patients with relapses often causes significant steroid toxicity. Patients with frequent relapses or steroid dependency thus require alternative treatment, and so far, cyclophosphamide or levamisole have been regarded as first-choice options, although the latter is no longer available in many countries. Data are accumulating that mycophenolic acid may be an alternative for these patients. Calcineurin inhibitors (cyclosporine A or tacrolimus) are usually effective and are often used after cytotoxic treatment, but long-term treatment is necessary, raising concerns regarding the accumulation of side effects. Still, some patients show a tendency to relapse even on this maintenance regimen and some even have a refractory course that creates a medical dilemma. For this situation, recent data have demonstrated an effect of monoclonal antibodies directed to B cells - rituximab, a drug that may also prove to be a therapeutic option in less complicated cases. Patients that do not respond to initial steroid treatment need genetic testing and a renal biopsy, since focal segmental glomerulosclerosis may be present. Treatment options include pulse methylprednisolone, often in addition to calcineurin inhibitors (mainly cyclosporine but also, recently, tacrolimus). Cyctotoxic treatment, especially intravenous cyclophosphamide, has been found to be effective in steroid-resistant nephrotic syndrome by some studies but is inferior to calcineurin inhibitors. In addition, mycophenolic acid and rituximab have been used in children with primary focal segmental glomerulosclerosis; however, response seems to be inferior in comparison with patients with steroid-sensitive nephrotic syndrome. Taken together, idiopathic nephrotic syndrome, including steroid-sensitive as well as steroid-resistant patients, is a potentially serious disorder. Although much progress has been made in recent years and a wide arsenal of immunological interventions is available, some patients have a treatment refractory course. Prospective studies or at least standardization of treatment for complicated cases is urgently needed.

Sequential maintenance therapy with cyclosporin A and mycophenolate mofetil for sustained remission of childhood steroid-resistant nephrotic syndrome

BACKGROUND

There is currently no established standard for maintenance therapy of steroid-resistant nephrotic syndrome (SRNS). We report the long-term clinical course, medication, pharmacokinetic data, and renal function of 23 children with primary, non-familial SRNS with focal segmental glomerulosclerosis (FSGS).

METHODS

To achieve initial remission, patients were treated with high-dose intravenous (i. v.) methylprednisolone and oral cyclosporin A (CsA). Maintenance therapy included transient alternate day oral prednisolone, CsA and angiotensin-converting enzyme (ACE) inhibitors and/or angiotensin receptor blockers. In 18 patients, mycophenolate mofetil (MMF) (adjusted to achieve blood mycophenolic acid trough concentrations > 2 μg/mL) was sequentially added, and 16 patients were converted to MMF monotherapy.

RESULTS

During a mean follow-up time of 7.0 years (1.7-16.5 years; cumulative observation time 161 patient-years), sustained remission could be achieved in all patients. Five of 23 patients (21%) experienced 10 relapses; all responded to relapse therapy. Maintenance therapy could be permanently discontinued in seven patients (30%). After conversion from CsA to MMF, renal function improved significantly; the eGFR at last follow-up was 137 (range 106-198) mL/min × 1.73 m(2). The mean number of anti-hypertensive drugs decreased from 1.86 per patient after initial remission to 0.57 on MMF monotherapy (P < 0.002).

CONCLUSIONS

The data of this uncontrolled retrospective study indicate that in children with SRNS/FSGS achieving initial remission, a sequential steroid-free therapy consisting of a combination of CsA and MMF followed by MMF alone (with the addition of ACE inhibitors and angiotensin receptor blockers), can provide sustained long-term remission, preservation of renal function and better control of blood pressure.

Mycophenolate mofetil therapy for children with steroid-resistant nephrotic syndrome

Treating children with steroid-resistant nephrotic syndrome (SRNS) has been a clinical challenge for pediatricians. We recruited 24 children (18 boys and six girls) with steroid-resistant idiopathic nephrotic syndrome (SRINS) who were <2 years. All patients were administered prednisone 2 mg/kg per day prior to mycophenolate mofetil (MMF). By the end of the eighth week, MMF was initiated at 25-30 mg/kg daily for 6- 12 months. Prednisone dose was reduced stepwise. Biochemical assays were performed every 2 months. Complete remission was achieved in 15 patients, partial remission in six, and no response to MMF was noted in three. With MMF treatment, the levels of urinary protein and serum cholesterol decreased and that of serum albumin increased in a time-dependant manner. We demonstrated the MMF could reduce proteinuria in SRINS children <2 years. Our study suggests that MMF therapy might be an effective strategy for treating SRINS in children <2 years.

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.

Long-term follow-up after cyclophosphamide and cyclosporine-A therapy in steroid-dependent and -resistant nephrotic syndrome

A retrospective study was made on 37 children with idiopathic nephrotic syndrome (INS). At the beginning, all patients were steroid sensitive but received more than one steroid course (median 4). Following several relapses, they became steroid dependent or steroid resistant. Group 1 consisted of 22 children [3 focal segmental glomerulosclerosis (FSGS), 19 minimal-change NS (MCNS)] who received cyclophosphamide (CP) orally for 2.5 +/- 0.5 months. Group 2 consisted of 15 children (7 FSGS, 8 MCNS) who received cyclosporine-A (CSA) for 28 +/- 15 months. The level of proteinuria decreased significantly and remained low during the follow-up. The relapse-free period was significantly longer in the CP group (CP 30 +/- 21.5; CSA 26.2 +/- 18 months, p < 0.001). The relapse rate decreased significantly in both groups and remained in this lower level during the follow-up (from 3.4 +/- 2.8 to 0.1 +/- 0.2/year in group 1, and from 3.7 +/- 3.1 to 0.6 +/- 0.8/year in group 2). At the end of the 5-year follow-up, 20/22 patients (90.9%) and 10/15 patients (66.6%) were in remission in groups 1 and 2 respectively, with or without treatment (p < 0.05). In the long term, both CP and CSA is effective second-line therapy following steroid monotherapy in INS patients, but the relapse rate was lower and the relapse free period was significantly longer in the CP-treated group.

Evaluation and management of steroid-unresponsive nephrotic syndrome

PURPOSE OF REVIEW

Idiopathic nephrotic syndrome in children is commonly associated with minimal change disease and response to steroid therapy. Steroid-unresponsive nephrotic syndrome is often characterized by persistent proteinuria and progression to chronic kidney disease. Focal segmental glomerulosclerosis is the leading cause of steroid-unresponsive nephrotic syndrome in childhood. There is no uniformed consensus as to the treatment of steroid-unresponsive nephrotic syndrome. Advances in the pathogenesis, genetics and biomarkers or surrogate markers may be useful for the diagnosis and identification of patients with steroid-unresponsive nephrotic syndrome, severity of disease, progression and response to therapy.

RECENT FINDINGS

This review is intended to describe some of the recent changes in the epidemiology of steroid-unresponsive nephrotic syndrome, in particular focal segmental glomerulosclerosis, its pathogenesis and alternative therapies.

SUMMARY

Recent studies in both children and adults have shown an increase in the incidence of focal segmental sclerosis as a cause of steroid-unresponsive nephrotic syndrome. Advances in the pathogenesis and noninvasive methods of diagnosis may allow for the identification of steroid-responsive patients.