Steroid-resistant, cyclosporine-responsive, relapsing 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%).

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.

Cyclosporine A and steroid therapy in childhood steroid-resistant nephrotic syndrome

Background:

In children, idiopathic nephrotic syndrome (INS) is primarily treated using corticosteroids. When remission is not achieved, the coadministration of potent immunosuppressant therapy becomes imperative. Cyclosporine A (CsA) is reportedly associated with a higher incidence of remission in comparison with other immunosuppressive agents.

Methods:

The present study investigated the response of combination therapy using CsA and prednisolone in 30 Tunisian children with idiopathic steroid-resistant nephrotic syndrome (ISRNS). Renal histopathology was compatible with focal segmental glomerular sclerosis (FSGS) in 15 children, minimal change disease (MCD) in nine children, and diffuses mesangiale proliferation (DMP) in six children.

Results:

The therapy protocol produced a complete remission of proteinuria in 15 patients (50%) and a partial remission in nine patients (30%). Six patients (20%) showed no response to therapy. Progression to end stage renal disease occurred in five CsA-resistant children and in four CsA-responsive patients. CsA-related nephrotoxicity was detected by renal biopsy in one patient.

Conclusions:

CsA remains the primary cytotoxic treatment for childhood steroid-resistant nephrotic syndrome. Its use in combination with corticosteroids provides optimum efficiency without high risk of nephrotoxicity.

Cyclosporine and steroid therapy in children with steroid-resistant nephrotic syndrome

We conducted a prospective, multicenter trial to evaluate the efficacy and safety of a 12-month course of cyclosporine in children with steroid-resistant nephrotic syndrome (SRNS). Thirty-five patients were enrolled, of whom 28 had minimal change or diffuse mesangial proliferation (MC/DMP), and seven had focal segmental glomerulosclerosis (FSGS). All patients received cyclosporine and prednisolone; patients with FSGS additionally received methylprednisolone pulse therapy (MPT). The dose of cyclosporine was adjusted to maintain a trough level of 120-150 ng/ml during the initial 3 months of treatment, followed by 80-100 ng/ml during months 4-12. The primary end point was the remission rate at month 12. Remission was achieved in 23 of 28 (82.1%) patients in the MC/DMP group and in six of the seven (85.7%) patients in the FSGS group. Follow-up renal biopsies were performed in 26 patients (nine at month 12, 17 at month 24), and cyclosporine-related nephrotoxicity was detected in one (3.8%). Major adverse events comprised severe bacterial infections (two patients) and posterior reversible encephalopathy syndrome (one patient). In conclusion, a high remission rate was achieved in our patient cohort using a combined cyclosporine/ prednisolone treatment regimen in children with SRNS who had MC/DMP and a combined cyclosporine/prednisolone plus MPT regimen in children who had FSGS.

Management of childhood onset nephrotic syndrome

The therapeutic approach to childhood nephrotic syndrome is based on a series of studies that began with an international collaborative effort sponsored by the International Study of Kidney Disease in Children in 1967. The characteristics of children presenting with nephrotic syndrome have changed over recent decades with greater frequency of the challenging condition focal segmental glomerulosclerosis and a greater prevalence of obesity and diabetes mellitus, which may be resistant to glucocorticoids in the former and exacerbated by long-term glucocorticoid therapy in the latter 2 conditions. The Children's Nephrotic Syndrome Consensus Conference was formed to systematically review the published literature and generate a children's primary nephrotic syndrome guideline for use in educational, therapeutic, and research venues.

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.

Long-term effects of cyclosporine in children with idiopathic nephrotic syndrome: a single-centre experience

BACKGROUND

Because of its potential nephrotoxicity, the long-term use of cyclosporine (CsA) as treatment for nephrotic syndrome (NS) is controversial. The clinical outcome of the patients with NS treated with CsA is unclear.

METHODS

This study reports the results of long-term CsA treatment in 117 children with idiopathic NS, who received CsA therapy for more than 2 years (median, 34 months). The mean age of children at initiation of CsA therapy was 11+/-4 years. The starting dose of CsA was 5 mg/kg/day, adjusted to maintain a trough level of 100-150 ng/ml in the first 2 months, 50-100 ng/ml thereafter. Later, a level as low as 30 ng/ml was accepted so long as it maintained remission. All patients received CsA between 1993 and 2003. Indications for treatment included steroid-dependent nephrotic syndrome (SDNS) in 74 patients and steroid-resistant nephrotic syndrome (SRNS) in 43 patients. Initial renal histology showed minimal change disease (MCD) in 38 patients and focal segmental glomerulosclerosis (FSGS) in 79 patients. Most patients were receiving moderate doses of prednisone. Sixty patients received cyclophosphamide prior to CsA. The observation periods were 5.8+/-3 years and 6.1+/-1.9 years before and after CsA treatment, respectively.

RESULTS

Complete remission [proteinuria <4 mg/h/m2/body surface area (BSA)], partial remission (proteinuria between 4.1 and 40 mg/h/m2/BSA) and resistance to CsA (proteinuria > or = 45 mg/h/m2/BSA) were observed in 82.1, 5.1 and 12.8%, respectively. Hypertension, renal impairment (>30% rise of serum creatinine), gingival hyperplasia and hypertrichosis occurred in 10.3, 6.0, 32.5 and 70.1%, respectively. Steroids were stopped in 102 patients, of which 31 relapsed. Out of 29 patients for whom CsA was intentionally discontinued while in remission, 22 relapsed. Of these, six patients were resistant to a second course of CsA. Post-therapy biopsies, performed in 45 patients (33 with SDNS and 12 with SRNS), showed mild stripped interstitial fibrosis and tubular atrophy in two SDNS patients (4.4%). At the last follow-up, one child had developed end-stage renal failure and two had chronic renal insufficiency.

CONCLUSIONS

Long-term CsA therapy in low doses is effective in the treatment of children with idiopathic NS, but the rate of relapse is high after drug withdrawal. Hypertension developed in 10% of patients and renal insufficiency in 6% (most patients with FSGS).

Mycophenolate mofetil in children with steroid-dependent and/or frequently relapsing nephrotic syndrome

BACKGROUND

Mycophenolate mofetil (MMF) has emerged as a new agent for treatment of a variety of glomerular diseases. This study examines the safety and efficacy of MMF in treating pediatric patients with steroid-dependent (SD) and/or frequently relapsing (FR) nephrotic syndrome (NS).

METHODS

We retrospectively reviewed the medical records of 18 patients with SDNS and/or FRNS treated with MMF for at least 3 months. MMF was used in 11 patients with SDNS (n=10) and FRNS (n=1), including 7 males and 4 females.

RESULTS

Mean age at time of diagnosis of NS was 3.3 years (range, 1.1-8.5 years), and at the start of MMF 5.9 years (range, 2.9-10 years). Seven patients had a renal biopsy prior to starting MMF; all had mesangial proliferative glomerulonephritis. Mean follow-up after starting MMF was 12.2 months (range, 4-24 months). Mean MMF dose was 948 mg/m2/day (range, 500-1087 mg/m2/day). MMF resulted in improvement in 9 of 11 patients, with 8 patients weaned off steroids completely, with a reduction in the mean relapse rate from 4.7 relapses/patient/year (range, 2.4-6) before MMF to 1.05 relapses/patient/year (range, 0-4.5) after MMF therapy (P=0.0001). The relative risk for relapse before MMF was 4.7 (P=0.0002). None of the patients had significant adverse events or intolerance to MMFtherapy.

CONCLUSION

We conclude that MMF is a safe and effective option for treatment of children with SDNS and/or FRNS.

Management of nephrotic syndrome in children

Idiopathic childhood nephrotic syndrome generally has a favorable long-term prognosis. Prompt administration of and improved guidelines for monitoring therapy have decreased morbidity and mortality. The treatment goal is to induce prompt remission while minimizing complications and adverse events. Aggressive therapy induces remission and decreases the frequency of relapse in most patient populations; however, such treatment often results in unnecessary toxicity. We critically assessed the current clinical evidence that supports each pharmacologic therapy. For each drug regimen, the risks and monitoring parameters required to reduce complications and optimize therapy are discussed. Some of the treatments are the common corticosteroid approaches, cytotoxic therapies (chlorambucil, cyclophosphamide), cyclosporine, less frequently used drugs (e.g., levamisole), and experimental therapies. Further studies are needed to identify the most effective and least toxic therapeutic regimens for inducing and maintaining remission in children with nephrotic syndrome.

Long-term treatment of focal segmental glomerulosclerosis in children with cyclosporine given as a single daily dose

Cyclosporine (CsA) has been successfully used for treatment of children with focal segmental glomerulosclerosis (FSGS) and nephrotic syndrome (NS) for the last decade. Response rates of 50% to 100% have been reported using twice-daily dosing of 5 to 32 mg/kg/d, achieving trough blood levels of 70 to 500 ng/mL. Treatment has been associated with a high incidence of side effects, including nephrotoxicity, hypertension, gingival hyperplasia, and hirsutism. To determine whether once-daily low-dose CsA could minimize side effects and still induce remission, 21 children with biopsy-proven FSGS and NS, each treated with CsA, 4.6 +/- 0.8 mg/kg/d, with no predetermined target trough blood levels, were studied. Eleven of 21 children (52%) attained complete remission and 5 of 21 children (24%) attained partial remission, for a total response rate of 76%. Mean time to response was 2.8 +/- 0.8 months, and mean duration of therapy was 20.6 +/- 13.7 months. CsA dosage was tapered or stopped in 9 responders; 3 of these patients maintained remission at last follow-up 6 to 13 months later, and 6 patients relapsed at 1.5 to 18.7 months (mean, 8.7 months). Five of these 6 patients responded again when CsA therapy was restarted or the dosage was increased. Twelve of 16 responders were still being administered CsA at last follow-up 11 to 60 months (mean, 24.6 months) later. Five of 21 patients (24%) had no response to CsA during 2 to 27 months of therapy; 4 of these 5 patients developed end-stage renal disease after CsA therapy was stopped. Side effects of CsA therapy were minimal: 1 patient each developed new-onset hypertension or gingival hyperplasia, and no patient had hirsutism or nephrotoxicity. Single daily low-dose CsA appears to be effective for long-term treatment of children with FSGS and NS, with fewer side effects than twice-daily dosing.

Focal segmental glomerulosclerosis

Over the last 2 decades, we have learnt that focal segmental glomerulosclerosis (FSGS) is a ubiquitous phenomenon underlying the progressive deterioration of many different types of renal diseases in both pediatric and adult populations. FSGS may also be the primary renal lesion, whether in new disease entities such as glycogen storage disease and human immunodeficiency virus infection, or in idiopathic FSGS. Although the mechanism which triggers the development of primary FSGS still remains unknown, laboratory and clinical studies have identified several key pathophysiological events leading to end-stage renal disease. While therapeutic modalities have not changed remarkably, a recent study, although uncontrolled, demonstrated an impressive efficacy of intravenous steroid pulse therapy in inducing remission. Nevertheless, it remains largely unknown whether such a forced remission decreases the overall risk of developing chronic renal failure. Studies have revealed an important pathophysiological role of angiotensin and the therapeutic efficacy of angiotensin converting enzyme inhibitors in progressive loss of renal function in diseases where glomerulosclerosis is secondary; however, it remains to be verified whether these results hold true in primary FSGS. As a result of the improvement in allograft survival rate, the benefit of renal transplant outweighs the risk of recurrence of FSGS, hence transplantation continues to be a vital therapy for FSGS patients who have reached renal failure. Thus, FSGS is not one disease, but rather a range of lesions seen in many settings. The type of lesions and the patient's unique genetic factors contribute to prognosis, and also may dictate choice of optimum therapy.