Steroid-Dependent Nephrotic Syndrome - Department of Medicine
Transcript of Steroid-Dependent Nephrotic Syndrome - Department of Medicine
Idiopathic Nephrotic Syndrome
• Nephrotic syndrome without known etiology • Heavy Proteinuria > 3.5 g/d in adults or > 1.0 g/m² in children
• Hypoalbuminemia < 3.0 g/dL in adults or < 2.5 g/dL in children
• Edema
• Hypercholesterolemia
• The three leading histological variants associated with INS are: • Minimal change disease (MCD)
• Focal segmental glomerulosclerosis (FSGS)
• Membranous nephropathy (MGN)
• Prolonged nephrotic range proteinuria leads to renal scarring and eventual renal failure
Idiopathic Nephrotic Syndrome
• The duration and severity of proteinuria are known to be surrogate markers of the progression of glomerular disease
• The main factor predicting the prognosis in all the histologic variants of the INS is the response of proteinuria to therapy
• Therefore the objectives of treatment are: • To lower proteinuria
• To reduce the frequency of relapses of nephrotic syndrome
• To protect the kidney and prevent progression to ESRD
Inherited Causes of Nephrotic Syndrome
• Autosomal recessive – present in childhood • Nephrotic syndrome type I (NPHS1), also called Congenital
nephrotic syndrome of the Finnish type (CNF) • Mutation in the gene NPHS1 on chromosome 19
• Nephrin, a transmembrane protein expressed in podocytes
• Nephrotic syndrome type 2 (NPHS2), also known as corticosteroid-resistant nephrotic syndrome
• Mutation in NPHS2 on chromosome 1
• Podocin
• Isolated diffuse mesangial sclerosis • Mutation in PLCE1 that codes for PLCε1
Treatment of Idiopathic Nephrotic Syndrome
• First line = Corticosteroids
• Second line agents: • Calcineurin inhibitors
• Cyclosporine
• Tacrolimus
• Alkylating agents • Cyclophosphamide
• Levamisole – not available in the US
• Mycophenolate mofetil
• Rituximab
Corticosteroids
• >95% of children with MCD achieve complete remission of proteinuria after 8 week course of steroids
• 50-60% remission rate in adults
• More than half of all patients who are initially steroid responsive go on to experience relapses of their nephrotic syndrome
• Frequent relapsers (> 2 episodes in 6 months) are at greater risk of becoming steroid dependent
• Subsequent prolonged therapy with steroids is undesireable due to the potential side effects, therefore alternative therapies are required in these patients
Cyclophosphamide
• Randomized trial of 30 children with steroid-sensitive frequently relapsing nephrotic syndrome
• After achieving complete remission with Prednisolone, patients were randomized to two groups: • Cyclophosphamide 3mg/kg/day x 8 weeks plus maintenance
Prednisolone followed by steroid taper
• Prednisolone taper alone
Barratt, et al. Lancet (1970) 479-482
Long-term follow-up after treatment with Cyclophosphamide
• Retrospective study of 143 children with frequently-relapsing or steroid dependent nephrotic syndrome who were treated with Cyclophosphamide
• Multicenter study, with median of 7.8 yrs follow-up (up to 15 yrs)
• Objective of the study was to look at long-term effects of cyclophosphamide and to identify parameters that might predict response to treatment
• Patients included in the study had received Cyclophosphamide 2-2.5 mg/kg/day for 10-12 weeks
Cammas, et al. NDT (2011) 26: 178-184
Cyclosporine
• 20 children (age 3-18) with steroid resistant or steroid dependent nephrotic syndrome • 13 were steroid resistant (no response to 60mg/m² Prednisone x
8 wks)
• 7 were steroid dependent (recurrence of proteniuria when the dose of Prednisone was discontinued)
• Prior administration of Chlorambucil or Cyclophosphamide
• Treated with Cyclosporine A for 8 weeks then abruptly discontinued • 7mg/kg/day titrated to blood level 100-200ng/ml
Tejani, et al. KI (1988) 33:729-734
Results • 14/20 achieved remission (disappearance of edema,
resolution of proteinuria for at least 3 days, serum albumin >2.5mg/dl, and normalization of cholesterol)
• There was reduction in proteinuria in the 6 who did not remit
• 40% sustained remission at 1 yr after discontinuation of tx:
Tejani, et al. KI (1988) 33:729-734
Tacrolimus
• Retrospective cohort study of 10 children with steroid-dependent nephrotic syndrome who were treated with Tacrolimus
• 9 pts with minimal change on biopsy, 1 with FSGS
• All patients had initially responded to steroids, and were then treated with Cyclophosphamide followed by Cyclosporine and then TAC as steroid sparing agents
• Patients received TAC 0.1 mg/kg/day in two divided doses, with a target trough level of 5-10 μg/L
• Compared the responses to TAC vs Cyclosporine • # of relapses per year
• Amount of Prednisone required
Sinha, et al. NDT (2006) 21: 1848-1854
• Mean duration of treatment with CYA was 2 yrs and subsequently with TAC was 5 yrs
• Adverse events: • CYA – decrease in GFR (4 pts), histological evidence of CNI toxicity
(2 pts), and new onset HTN (1 pt) • TAC – new onset HTN (1 pt), new insulin-dependent diabetes (1 pt)
and CNI toxicity (1 pt) • Overall, no benefit to using TAC over CYA
Sinha, et al. NDT (2006) 21: 1848-1854
Cyclosporine vs Cyclophosphamide
• Prospective, randomized, multicenter, controlled study
• 73 patients with steroid-sensitive idiopathic NS (frequent relapses or steroid dependence) • 11 adults and 55 children (7 lost to follow-up not included)
• After inducing remission with Prednisone, patients were randomized to receive: • Cyclophosphamide 2.5mg/kg/day x 8 weeks
• Cyclosporine 5mg/kg/day (in adults) or 6mg/kg/day (in children) x 9months then tapered off over 3 months
Ponticelli, et al. NDT (1993) 8: 1326-1332
Mycophenolate mofetil
• Prospective, multicenter, open-label study looking at the efficacy of MMF in children with frequently relapsing nephrotic syndrome
• 33 patients, all in remission at the time of the study • Age 6.8 yrs +/- 2.7 (range 2-15)
• 56% male, 44% female
• 6/33 were steroid dependent
• Received MMF 600 mg/m² BID x 6 months; Prednisone was tapered over the first 16 weeks
Hogg, et al. CJASN (2006) 1: 1173-1178
Hogg, et al. CJASN (2006) 1: 1173-1178
• Adverse events: • One pt discontinued MMF because of
an ANC of 300/mm² • One pt was hospitalized for a varicella
outbreak while on MMF
MMF in adults
• 7 patients (age range 21-35 yrs) with minimal change disease or FSGS who had multiple relapses of nephrotic syndrome despite treatment with cytotoxic drugs
• All of the patients were initially steroid responsive; 6 were steroid dependent by the time of the study
• 6/7 had relapsing disease for >10 yrs, with treatment-related side affects
• Patients received MMF 1g BID together with Prednisolone • Treatment length ranged from 9 to 21 months
Day, et al. NDT (2002) 17: 2011-2013
• 6 patients went into complete remission (urine albumin 0g/24h) and the 7th went in to partial remission (urine albumin <2g/24h)
• 5 patients were still in complete remission at last follow-up (avg 10 months)
• No episodes of GI side effects or leukopenia requiring dose reduction
Day, et al. NDT (2002) 17: 2011-2013
Rituximab
• Cohort study of 57 patients with steroid-dependent or steroid resistant nephrotic syndrome • 33 with SRNS and 24 with SDNS
• Mean ages of 12.7 (+/- 9.1) and 11.7 (+/- 2.9) years, respectively
• All patients had failed treatment with cytotoxic agents in the past, either Cyclophosphamide, Calcineurin inhibitors, or had toxicity with steroids or cytotoxic agents
• Received Rituximab 375 mg/m² weekly x 2 doses (SDNS) or 4 doses (SRNS) • Steroids were tapered over several months
• Cyclosporine doses significantly reduced
• Followed for at least 12 months after treatment
Gulati, et al. CJASN (2010) 5; 2207-2212
Rituximab • Randomized-controlled trial designed to show that Rituximab added
to lower doses of Prednisone and Calcineurin inhibitors was non-inferior to standard doses
• 54 children (mean age 11 +/- 4 years) with Idiopathic nephrotic syndrome
• Included patients who had been on steroids and calcineurin inhibitors for at least 12 months and who had been in remission for at least 6 months
• Stratified patients by presence of toxicity secondary to steroids or cyclosporine
• Intervention: Rituximab 375mg/m² IV once (in patients without toxicity) or twice (in patients with toxicity) • Prednisone and calcineurin inhibitors were tapered off over 45 days
• Control: Standard therapy with steroids and calcineurin inhibitors • Primary outcome: Percentage change in proteinuria at 3 months
Ravani, et al. CJASN (2011) 6: 1308-1315