Corticothérapie prolongée chez l’enfant : quelle place pour un traitement adjuvant dans le syndrome néphrotique ?

[Cyclophosphamide in idiopathic nephrotic syndrome: Outcome and outlook]

INTRODUCTION

Cyclophosphamide (CYP) has been used for over 40 years in patients with steroid-sensitive nephrotic syndrome (NSSS) presenting frequent relapses (NSRF) or steroid dependence (NSSD). However, the long-term success of treatment with cyclophosphamide is difficult to predict. The objectives of this study are to determine long-term outcomes of cyclophosphamide and identify the factors associated with sustained remission.

METHODS

We retrospectively studied the data from 50 patients with idiopathic nephrotic syndrome, treated by oral cyclophosphamide and followed at service of pediatric for more than 8 years for idiopathic nephrotic syndrome and related factors for survival without relapse were evaluated by univariate analysis.

RESULTS

The median age at the time of diagnosis was 4.3 years, and median follow-up time was 1.7 years with the median of 8 years at the first use of CYC. Patients had received a median cumulative dose of 168mg/kg. At the end of follow-up, 38% of patients entered into remission after using CYC while 62% failed to respond and further relapses then occur. The median time of stopping corticosteroid therapy was three month. The survival without relapse was respectively 56% (28 patients), 52% (26 patients), 48% (24 patients), and 38% (19 patients), at 6 months, one year, two years and more than two years. In univariate analysis, the survival without relapse was related to the age at the moment of starting the therapy par CYC (the median was 5 months for an age < 8 years and 41 months for an age≥8 years; P=0.049), the type of nephrotic syndrome [36 months for SNRF, 4 months for NSSD and nephrothic syndrome steroid resistant (NSSR); P=0.068], and the histological lesion (6 months for diffuse mesangial proliferation, 2 months for segmental glomerulosclerosis; P=0.009). The age at the moment of diagnosis, the sex and the cumulative dose of CYC did not have significant influence.

CONCLUSION

The results presented in this study suggest the use of oral cyclophosphamide for short period remain second line effective therapy. Further well-designed trials are required to evaluate the efficacy of other steroid-sparing agents.

Change in Bone Mineral Density and Role of Vitamin D and Calcium Supplementation During Treatment of First Episode Nephrotic Syndrome

Introduction

Nephrotic Syndrome (NS) is one of the common illnesses in childhood. Oral glucocorticoids are mainstay of treatment, which are known to cause various short term and long term adverse effects including osteoporosis. Children with first episode and infrequent relapsing NS are not prescribed Calcium (Ca) and Vitamin D (VitD) supplements routinely.

Aim

To observe change in Bone Mineral Density (BMD) in children during first episode of NS and role of VitD and Ca supplementation during the treatment of first episode of NS.

Materials and Methods

A double blind randomized control trial was conducted in Department of Paediatrics at a tertiary care center in New Delhi, India, from October 2011 to March 2013. Three groups were made, each having sample size of 20. Group A (intervention group) consisted of first episode NS patients who received steroids along with VitD and Ca supplements. Group B (placebo group) had children with first episode of NS treated with steroids and placebo. Biochemical tests and BMD assessment were done at start and after three months of steroid treatment. Groupwise differences in BMD, VitD, Ca, Phosphate (PO₄) and Alkaline Phosphatase (ALP) were assessed at baseline and after three months through Analysis Of Variance (ANOVA). Linear regression models for repeated measures were used to test the association between different variables and BMD and also between various study groups.

Results

Among study population, Group B had significant decrease in VitD levels (28.85±5.52 ng/dl to 14.22±1.36 ng/dl) than to Group A (23.59±6.08 ng/dl to 13.27±1.35 ng/dl) after three months of steroid treatment. Similarly BMD decreased significantly in Group B (-0.033g/cm²) as compared to Group A (0.001g/cm²) showing significant decrease in VitD and BMD in children with first episode of NS after three months of steroid treatment whereas use of VitD and Ca supplements improves the deficit.

Conclusion

Ca and VitD supplement should be used during treatment of first episode of NS, but further studies are required to ascertain the adequate dose for the same.

The influence of glomerular filtration rate and age on fibroblast growth factor 23 serum levels in pediatric chronic kidney disease

BACKGROUND

Fibroblast growth factor 23 (FGF23) is a phosphaturic factor and a suppressor of 1alpha-hydroxylase activity in the kidney. Although its importance in chronic kidney disease (CKD) has been demonstrated in adults, there is little information in pediatric patients.

OBJECTIVES

The aims of this study were: 1) to determine reference values for FGF23 serum levels according to glomerular filtration rate (GFR) (measured by the reference standard, inulin clearance), gender, and age; and 2) to evaluate the effects of different etiologies and treatments on FGF23 serum levels in a prospective single-center cohort of 227 CKD children (119 boys).

RESULTS

Age, body weight, height, and GFR (mean +/- sd) values were: 11.3 +/- 4.1 yr, 37 +/- 16 kg, 140 +/- 20 cm, and 98 +/- 34 ml/min per 1.73 m(2), respectively. Calcium, phosphate, PTH, 25 hydroxyvitamin D, 1,25 dihydroxyvitamin D, C-terminal FGF23, and intact FGF23 (mean +/- sd) levels were: 2.43 +/- 0.11 mmol/liter, 1.41 +/- 0.22 mmol/liter, 41 +/- 23 pg/ml, 24 +/- 10 ng/ml, 152 +/- 72 pmol/liter, 76 +/- 134 relative units/ml, and 44 +/- 37 pg/ml, respectively. There was a wide range of FGF23 serum levels, but FGF23 levels increased when GFR decreased. FGF23 serum levels were not modified by gender, but they increased with age. In univariate analysis, corticosteroid therapy seemed to be associated with increased FGF23 serum levels. A multivariate linear regression analysis found a significant impact of GFR, body mass index, and solid organ transplantation on FGF23 serum levels.

CONCLUSION

Age, GFR, body mass index, and solid organ transplantation seem to influence FGF23 serum levels in a pediatric population. The impact of corticosteroids on FGF23 metabolism should be further investigated; further longitudinal studies will also help to better define the prognostic impact of FGF23 serum levels in pediatric CKD in terms of disease progression, cardiovascular morbidities, and bone disabilities.