Cyclophosphamide in steroid-dependent nephrotic syndrome

Predictive factors of long-term disease remission after rituximab administration in patients with childhood-onset complicated steroid-dependent nephrotic syndrome: a single-center retrospective study

BACKGROUND

Despite the fact that rituximab (RTX)-associated adverse events may be relatively frequent in younger patients, recent studies have reported RTX as a suitable first-line steroid-sparing agent for maintaining remission in children with steroid-dependent nephrotic syndrome (SDNS). However, the impact of age at RTX initiation on the long-term outcome remains unknown in this cohort.

METHODS

We retrospectively reviewed the clinical course of 61 patients with complicated SDNS who received a single dose of RTX (375 mg/m2) followed by maintenance immunosuppressive agents (IS) from January 2008 to March 2021. In patients who achieved > 12 months of prednisolone-free remission, IS tapering within 6 months was tried to achieve. The primary endpoint was the probability of achieving long-term treatment-free remission at the last follow-up.

RESULTS

After RTX initiation, 52 patients (85.2%) relapsed after a median of 665 days, and 44 patients (72.1%) received additional RTX doses (total, 226 infusions). At the last follow-up (median observation period, 8.3 years; median age, 18.3 years), 16 patients (26.2%) achieved long-term remission. Multivariate analysis showed that older age at RTX initiation was the independent predictive factor for achieving long-term remission (odds ratio, 1.25; p < 0.05). The proportion of those who achieved long-term remission was significantly higher in patients aged ≥ 13.5 years than in those aged < 13.5 years at RTX initiation (52.6 vs 14.3%, p < 0.05). Persistent severe hypogammaglobulinemia did not develop in older children (≥ 13.5 years) at RTX initiation.

CONCLUSION

For older children with complicated SDNS, RTX appeared to be a suitable disease-modifying therapy without persistent adverse events.

IPNA clinical practice recommendations for the diagnosis and management of children with steroid-sensitive nephrotic syndrome

Idiopathic nephrotic syndrome is the most frequent pediatric glomerular disease, affecting from 1.15 to 16.9 per 100,000 children per year globally. It is characterized by massive proteinuria, hypoalbuminemia, and/or concomitant edema. Approximately 85-90% of patients attain complete remission of proteinuria within 4-6 weeks of treatment with glucocorticoids, and therefore, have steroid-sensitive nephrotic syndrome (SSNS). Among those patients who are steroid sensitive, 70-80% will have at least one relapse during follow-up, and up to 50% of these patients will experience frequent relapses or become dependent on glucocorticoids to maintain remission. The dose and duration of steroid treatment to prolong time between relapses remains a subject of much debate, and patients continue to experience a high prevalence of steroid-related morbidity. Various steroid-sparing immunosuppressive drugs have been used in clinical practice; however, there is marked practice variation in the selection of these drugs and timing of their introduction during the course of the disease. Therefore, international evidence-based clinical practice recommendations (CPRs) are needed to guide clinical practice and reduce practice variation. The International Pediatric Nephrology Association (IPNA) convened a team of experts including pediatric nephrologists, an adult nephrologist, and a patient representative to develop comprehensive CPRs on the diagnosis and management of SSNS in children. After performing a systematic literature review on 12 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, recommendations were formulated and formally graded at several virtual consensus meetings. New definitions for treatment outcomes to help guide change of therapy and recommendations for important research questions are given.

Long-term obesity prevalence and linear growth in children with idiopathic nephrotic syndrome: is normal growth and weight control possible with steroid-sparing drugs and low-dose steroids for relapses?

BACKGROUND

Long-term steroid treatment in children is known to cause obesity and negatively affect growth. The objective of this study was to determine the prevalence of obesity and overweight and analyze linear growth in children with nephrotic syndrome.

METHODS

The study involved 265 children treated with glucocorticoids for nephrotic syndrome for a mean duration of 43 months (range: 6-167, IQR: 17, 63.3). Height, weight, and BMI SDS were recorded at each visit. Rate of change between the final and initial height, weight, and BMI was calculated (Δ score). The cumulative steroid dose (mg/kg/day) during follow-up was calculated. Relapses without significant edema were treated with low-dose steroids and steroid-sparing drugs were used in children with steroid dependency/frequent relapses.

RESULTS

Mean first BMI SDS was + 1.40 ± 1.30 and final + 0.79 ± 1.30. At initial assessment, 41.4% of the patients were obese (BMI ≥ 95^th percentile) and 19.5% were overweight (BMI 85^th-95^th percentile). At the last clinical visit, 24% were obese and 17% overweight. The children had lower BMI SDS at last clinical visit compared to initial assessment. Mean first height SDS of the cohort was - 0.11 ± 1.22 and final score 0.078 ± 1.14 (p < 0.0001). Almost 85% of patients were treated with steroid-sparing drugs.

CONCLUSIONS

Our results indicate that children with nephrotic syndrome, despite a need for steroid treatment for active disease, can improve their obesity and overweight and also improve their linear growth from their first to last visit with us.

Nephrotic Syndrome

Nephrotic syndrome (NS) encompasses a variety of disease processes leading to heavy proteinuria and edema. Minimal change disease (MCD) remains the most common primary cause of NS, as well as the most responsive to pharmacologic treatment with often minimal to no chronic kidney disease. Other causes of NS include focal segmental glomerulosclerosis, which follows MCD, and secondary causes, including extrarenal or systemic diseases, infections, and drugs. Although initial diagnosis relies on clinical findings as well as urine and blood chemistries, renal biopsy and genetic testing are important diagnostic tools, especially when considering non-MCD NS. Moreover, biomarkers in urine and serum have become important areas for research in this disease. NS progression and prognosis are variable and depend on etiology, with corticosteroids being the mainstay of treatment. Other alternative therapies found to be successful in inducing and maintaining remission include calcineurin inhibitors and rituximab. Disease course can range from recurrent disease relapse with or without acute kidney injury to end-stage renal disease in some cases. Given the complex pathogenesis of NS, which remains incompletely understood, complications are numerous and diverse and include infections, electrolyte abnormalities, acute kidney injury, and thrombosis. Pediatricians must be aware of the presentation, complications, and overall long-term implications of NS and its treatment.

Oral cyclophosphamide therapy in 100 children with steroid-sensitive nephrotic syndrome: experience from a developing country

BACKGROUND

Oral cyclophosphamide (CYP) is an important therapeutic agent in treatment of steroid-sensitive nephrotic syndrome having a steroid-dependent (SD) or frequent relapsing (FR) course. This retrospective observational study aimed to determine response to oral CYP and factors associated with positive response in these patients.

METHODS

We studied 100 children (male; 75) with FR (19%) and SD (81%) NS treated with CYP in the Pediatric Nephrology clinic. Responders were defined as children in whom steroids were stopped for at least 6 months following CYP and factors affecting response were analysed. Relapse-free survival was estimated by Kaplan-Meier method.

RESULTS

Median age at onset of NS was 3 years (IQR 2-5.2). Median age at CYP was 5.7 years (IQR 3.7-7.9). Fifty percent of patients were in the responder group at 6 months of CYP. Relapse-free survival post CYP therapy was 31% at 1 year, 11% at 2 years. Factors predicting good response were age at onset of NS > 3 years with 61.2% response at 6 months (p = 0.028) and older age at CYP initiation (> 5 years) with 61% response (p = 0.008). Multivariate regression analysis showed age at start of CYP > 5 years was an independent factor for good response (p = 0.044, OR = 2.903, CI -1.03 to 8.18).

CONCLUSIONS

Judicious selection of patients, especially with age of onset of NS more than 3 years and initiation of CYP after age of 5 years, can predict better response in this group of patents.

A global antiB cell strategy combining obinutuzumab and daratumumab in severe pediatric nephrotic syndrome

BACKGROUND

Steroid-sensitive nephrotic syndrome (SSNS) is, in most patients, a chronic disease with 80% experiencing at least one relapse after first flare. B cell depletion using rituximab is effective in preventing relapse in steroid-dependent (SDNS) patients but fails to maintain long-term remission following B cell recovery, possibly due to development of autoreactive long-lived plasma cells. We investigated sequential combination of antiCD20 antibody targeting all B cell subsets, and antiCD38 antibody with high plasma cell cytotoxicity in patients with uncontrolled SDNS after failure of one or several attempts at B cell depletion.

METHODS

Fourteen patients with median disease duration 7.8 years received 1000 mg/1.73 m² obinutuzumab followed by 1000 mg/1.73 m² daratumumab 2 weeks later. Oral immunosuppression was discontinued within 6 weeks, and biological monitoring performed monthly until B cell recovery.

RESULTS

Median age at treatment was 11.0 [IQR 10.4-14.4] years. B cell depletion was achieved in all patients, and B cell reconstitution occurred in all at median 9.5 months after obinutuzumab injection. After median follow-up 20.3 months (IQR 11.5-22.6), 5/14 patients relapsed including 4 within 100 days following B cell repletion. Relapse-free survival was 60% at 24 months from obinutuzumab infusion. Mild infusion reactions were reported in 3/14 patients during obinutuzumab and 4/14 during daratumumab infusions. Mild transient neutropenia (500-1000/mm³) occurred in 2/14 patients. Intravenous immunoglobulins were given to 12/14 patients due to hypogammaglobulinemia. Low IgA and IgM levels were noted in 8 and 14 patients, respectively. No severe infection was reported.

CONCLUSION

Global antiB cell strategy combining obinutuzumab and daratumumab induces prolonged peripheral B cell depletion and remission in children with difficult-to-treat SDNS.

Efficacy and safety of intravenous immunoglobulin with rituximab versus rituximab alone in childhood-onset steroid-dependent and frequently relapsing nephrotic syndrome: protocol for a multicentre randomised controlled trial

INTRODUCTION

Guidelines for the treatment of steroid-dependent nephrotic syndrome (SDNS) and frequently relapsing nephrotic syndrome (FRNS) are lacking. Given the substantial impact of SDNS/FRNS on quality of life, strategies aiming to provide long-term remission while minimising treatment side effects are needed. Several studies confirm that rituximab is effective in preventing early relapses in SDNS/FRNS; however, the long-term relapse rate remains high (~70% at 2 years). This trial will assess the association of intravenous immunoglobulins (IVIgs) to rituximab in patients with SDNS/FRNS and inform clinicians on whether IVIg's immunomodulatory properties can alter the course of the disease and reduce the use of immunosuppressive drugs and their side effects.

METHODS AND ANALYSIS

We conduct an open-label multicentre, randomised, parallel group in a 1:1 ratio, controlled, superiority trial to assess the safety and efficacy of a single infusion of rituximab followed by IVIg compared with rituximab alone in childhood-onset FRNS/SDNS. The primary outcome is the occurrence of first relapse within 24 months. Patients are allocated to receive either rituximab alone (375 mg/m²) or rituximab followed by IVIg, which includes an initial Ig dose of 2 g/kg, followed by 1.5 g/kg injections once a month for the following 5 months (maximum dose: 100 g).

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee (Comité de Protection des Personnes) of Ouest I and authorised by the French drug regulatory agency (Agence Nationale de Sécurité du Médicament et des Produits de Santé). Results of the primary study and the secondary aims will be disseminated through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03560011.

Treating the idiopathic nephrotic syndrome: are steroids the answer?

The use of steroids in idiopathic nephrotic syndrome is the major discovery of the twentieth century in the field of pediatric nephrology. At onset of the twenty-first century, steroids remain the first line of treatment at first flare. All the protocols to treat the first flare are similar by a common sequence including a first phase of daily prednisolone/prednisone at a dose of 60 mg/m²/day for at least 4 weeks followed by an alternate-day regimen for several weeks. It appears that a cumulated dose of 2240 mg/m² given in 8 weeks at the first flare without tapering sequence is not inferior to increased dose and duration in terms of prevalence of frequent relapsers and the subsequent cumulated dose of steroids at 24 months of follow-up. A higher cumulated dose might only be interesting in patients aged below 4 years although a formal demonstration is still missing. Several retrospective studies are concordant to suggest that intravenous methylprednisolone pulses are useful to reach a full urinary remission in case of oral resistance to 4 weeks of oral prednisone/prednisolone. A majority of patients have multiple relapses after the treatment of the first flare and half meet the definition of steroid dependency. In those patients, long-lasting alternate-day prednisone/prednisolone therapy does not lead to long-lasting remission, opening the question of the best strategy of immunosuppression.

Does cyclophosphamide still play a role in glomerular diseases?

Cyclophosphamide is a prodrug that is converted to inactive carboxy-cyclophosphamide, acrolein and phosphoramide mustard, an agent that adds alkyl groups to oxygen and nitrogen atoms of guanine, one of the four nitrogen bases that form the DNA nucleotides, causing DNA cross-links and introducing DNA breaks. These cytotoxic and mutagenic effects mainly occur in proliferating cells. Repair mechanisms may prevent DNA damage in quiescent cells, but they may be insufficient to contrast the side effects of cyclophosphamide if high doses of the drug are used. Most adverse events are dose- and age-dependent. Phosphoramide mustard can cause bone marrow toxicity, gonadal toxicity, and may favor the development of leukemia, bladder cancer and other types of malignancy. Acrolein can produce hemorrhagic cystitis and even bladder fibrosis when given for prolonged periods. A number of precautional measures should be taken to prevent these untoward events. In particular, long-term administration and high doses of cyclophosphamide should be avoided whenever possible. Today the indications to cyclophosphamide in glomerular diseases are more restricted than in the past, but the drug is still used as a steroid-sparing agent in steroid-sensitive minimal change disease and focal segmental glomerulosclerosis. In membranous nephropathy, cyclophosphamide, alternated or associated with corticosteroids, proved to be beneficial in obtaining remission of nephrotic syndrome and preserving renal function. Cyclophosphamide is considered as a first-line treatment for rapidly progressive glomerulonephritis and the hectic phases of lupus nephritis. In conclusion, cyclophosphamide is a cheap drug that may be useful in a number of glomerular diseases but it may lead to severe side effects. A close monitoring of blood count and clinical conditions, as well as low cumulative doses of cyclophosphamide are strongly recommended when using the drug in patients with renal diseases.

[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.

Autoantibodies against podocytic UCHL1 are associated with idiopathic nephrotic syndrome relapses and induce proteinuria in mice

Idiopathic steroid sensitive nephrotic syndrome (INS), the most frequent childhood nephropathy, is thought to be mediated by a circulating soluble factor that reversibly affects the renal protein sieving. The efficiency of rituximab therapy recently highlighted the involvement of B cells. Here we studied the involvement of a specific immunoglobulin G (IgG) in the disease. After plasma fractionation by size exclusion chromatography, a detachment of cultured podocyte was observed with one IgG-containing fraction from 47% patients in relapse, 9% of patients in remission and 0% of controls. Podocyte protein lysates were immunoprecipitated by IgG from those plasma fractions identifying a list of 41 podocyte proteins after proteomic analysis. Five podocyte targets were selected on statistical and biological criteria. Specific antibodies were tested and only anti-Ubiquitin Carboxyl-Terminal Hydrolase L1 (UCHL1) IgG led to podocyte detachment. UCHL1 was mainly found inside the podocyte but also weakly expressed on podocyte cell surface. Incubation of either anti-UCHL1 IgG or plasma fractions with recombinant UCHL1 prevented podocyte detachment. Plasma levels of anti-UCHL1 IgG were significantly increased in relapsing INS patients compared to patients in remission and controls. Proteinuria correlated with anti-UCHL1 IgG level at various stages of the disease. Purified patient anti-UCHL1 antibodies induced proteinuria and podocyte foot effacement in mice. Altogether, these results identified UCHL1 as a target podocyte protein of autoantibodies in a set of relapsing patients and support a causative role of anti-UCHL1 autoantibodies in the development of INS.

[Treatments of steroid-dependent nephrotic syndrome in children]

Primary nephrotic syndrome (NS) is the most common glomerular disease in children. It is characterized by massive proteinuria and hypoalbuminemia. It typically has a sudden onset and more than 70% of patients will experience at least one relapse. An immunological origin has long been postulated, although the precise molecular mechanisms underlying the disease remain debated. Steroids are the first-line therapy with cumulative dose and duration of initial treatment varying among countries. Steroid-sparing agents may be indicated in case of steroid-dependency or frequent relapses. However, no consensus exists regarding the different treatment options. These treatments are mostly suspensive and therefore, need to be prolonged for several months. Levamisole, an antihelminthic drug, also has an immunomodulatory function, and alone or in combination with steroids, it can decrease cumulative steroid dose and relapses. It is usually well tolerated, and its principal side effects are cytopenia and elevated liver enzymes. Mycophenolate mofetil is an immunosuppressive agent whose reported side effects are cytopenia and diarrhea. Calcineurin inhibitors (cyclosporine or tacrolimus) have long been used in steroid-dependent patients. Their major side effects are hirsutism, gum hypertrophy, and nephrotoxicity, leading to interstitial kidney fibrosis and chronic kidney disease. Cyclophosphamide is an efficient treatment but its gonadal toxicity is a major drawback to its use. More recent drugs such as rituximab are very effective but require hospitalization for the infusion and induce an increased risk of opportunistic infection, prolonged neutropenia, and anaphylaxis. In this review, we present the available treatments, their indications, and the side effects.

Epidemiology of idiopathic nephrotic syndrome in children: endemic or epidemic?

BACKGROUND

The etiology of idiopathic nephrotic syndrome (INS) remains partially unknown. Viral infections have been reported to be associated with INS onset and relapse. The aim of this study was to describe the epidemiology of a population-based cohort of children with INS and propose a spatiotemporal analysis.

METHODS

All children aged 6 months to 15 years with INS onset between December 2007 and May 2010 and living in the Paris area were included in a prospective multicenter study. Demographic and clinical features at diagnosis and 2 years were collected.

RESULTS

INS was diagnosed in 188 children, 93 % of whom were steroid sensitive. Annual incidence was 3.35/100,000 children. Standardized incidence ratio (SIR) was higher in one of the eight counties: Seine-Saint-Denis, with SIR 1.43 [95 % confidence interval (CI) 1.02-1.95]. A spatial cluster was further identified with higher SIR 1.36 (95 % CI 1.09-1.67). Temporal analysis within this overincidence area showed seasonal variation, with a peak during the winter period (p <0.01). In addition, partition of the Paris area into quintiles of the population showed that the average delay of occurrence, with regard to the first study case, followed a longitudinal progression (p <0.0001).

CONCLUSION

The clustering of cases, the seasonal variation within this particular area, and the progression over the Paris area altogether suggest that INS may occur on an epidemic mode.

Efficacy of leflunomide combined with prednisone in the treatment of refractory nephrotic syndrome

OBJECTIVE

To assess the safety and clinical efficacy of leflunomide (LEF) and prednisone on refractory nephrotic syndrome (RNS).

METHODS

A total of 52 patients with RNS were treated for 24 weeks between 2010 and 2014 in our hospital. In the treated group, 26 patients were treated with LEF and prednisone, and, in the control group, 26 patients were treated with cyclophosphamide (CTX) and prednisone. During the treatment, 24 h urinary protein excretion and the serum levels of albumin and cholesterol, and kidney function were assayed before and after the therapy. Adverse reactions during treatment were recorded.

RESULTS

In the LEF group, the medication was markedly effective in eight cases and effective in nine cases; the total efficacy rate was 65.30%. In the CTX group, the treatment was markedly effective in six cases and effective in nine cases; the total efficacy rate was 57%. There were no significant differences between the results of the total efficacy rate (p > .05). The 24 h urinary protein excretion and serum cholesterol levels in both groups decreased after therapy and the serum levels of albumin in both groups increased after therapy. There were significant differences between the results for the 24 h urinary protein excretion, serum levels of albumin and cholesterol in the two groups (p < .05). The treatments were well tolerated in both groups.

CONCLUSION

LEF combined with prednisone has a certain efficacy on the RNS and displays few adverse reactions. A large-sample, randomized double-blind controlled study and long-term follow-up are needed to verify the efficacy of LEF combined with prednisone.

Mycophenolate mofetil in steroid-dependent idiopathic nephrotic syndrome

BACKGROUND

Prospective studies have established the mycophenolate mofetil (MMF) efficiency in childhood idiopathic nephrotic syndrome (INS) but reports on the long-term outcome are lacking. Moreover, the search for factors influencing its efficiency would be useful to define its place among the other treatments.

METHODS

We performed a monocentric retrospective study including 96 children with steroid-dependent INS followed for 4.7 years (median) (IQ 3-6) after the onset of MMF treatment. The characteristics of responder patients (n = 74), as defined by a 50 % decrease of relapse rate and/or a 60 % decrease of steroid dose, and of non-responder patients (n = 22) were compared by univariate analysis and multivariate logistic regression.

RESULTS

Withdrawal of prednisone was achieved in 48/96 patients after a median duration of 18.1 months (IQ 7.8-30.0) of MMF. Only 26/48 patients did not relapse under MMF alone. After MMF was stopped in these patients, only six remained in remission without any treatment at last follow-up. Responders had a shorter time to remission at the first flare (9.5 vs. 15 days, p = 0.02), a shorter disease duration prior to the onset of MMF (22.2 vs. 94.5 months, p = 0.001), and were younger at the MMF initiation (6.7 vs. 10.1 years, p = 0.02) than non-responder patients. The age of MMF initiation was an independent factor associated with efficiency (OR = 0.80, 95 % CI [0.69, 0.93], p < 0.01).

CONCLUSIONS

MMF is more efficient in young patients treated early in the disease course. Nevertheless, MMF has no remnant effect while nearly all patients relapsed after withdrawal of the drug.

Long-term results of children diagnosed with idiopathic nephrotic syndrome; single center experience

AIM

The aim of this study was to determine the long-term results of children followed up with a diagnosis of nephrotic syndrome in a single center.

MATERIALS AND METHOD

The medical data of 33 patients aged between 6 months and 10 years who were diagnosed with idiopathic nephrotic syndrome in our center between January 2000 and December 2012 and followed up for a period of 2-12 years were reviewed (Gulhane Military Medical Academy Ethics committee, 07.11.2012/10).

RESULTS

The mean age of disease onset was 3.2±2.04 years (range: 0.5-10 years) and the mean follow-up period was 6±3.4 years (range: 2-12 years). Thirteen (39.4%) of the study group (or the patients) were female and 20 (60.6%) were male. Twenty seven (1.8%) of the patients were sensitive to steroid and 6 (18.1%) were resistant to steroid. Four (12.1%) of the steroid-resistant patients had steroid-dependent nephrotic syndrome, 5 (15.2%) had frequently relapsing nephrotic syndrome and 18 (54.5%) had rarely relapsing nephrotic syndrome. Histopathological diagnoses of six patients who underwent biopsy because of resistance to steroid were as follows: focal segmental glomerulosclerosis (n=3), C1q nephropathy (n=1), diffuse mesangial proliferation (n=1) and membraneous nephropathy (n=1). Fifteen (45.5%) patients entered into full remission and 2 (6%) patients developed chronic renal failure. Treatment complications including decreased bone mineral density in three patients (9%), short stature in 2 patients (6%) and cataract in 2 patients (6%) developed.

CONCLUSIONS

Children with nephrotic syndrome carry a risk in terms of short stature, osteoporosis, cataract and renal failure in the long-term follow-up. It was observed that our rates of response to steroid were similar to the literature and the most common histopathological diagnosis was focal segmental glomerulosclerosis in our patients who underwent biopsy because of resistance to steroid. It was thought that multi-center studies should be conducted to demonstrate regional or national differences related with long-term results of childhood nephrotic syndrome.

Prevalence of herpesviruses at onset of idiopathic nephrotic syndrome

BACKGROUND

Idiopathic nephrotic syndrome (INS) is likely a primary immune disorder, but viruses might also be involved in the mechanisms of the disease. Here, we investigate the link between herpesvirus infection and the first manifestation of INS in children.

METHODS

A prospective, multicentre, and population-based case-control study called NEPHROVIR included 164 patients, aged 6 months to 15 years old, newly diagnosed with INS, and 233 controls matched for gender, age, and period of sample. The analysis was done on 124 patients and 196 controls. Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus-6 (HHV-6), and human herpesvirus-7 (HHV-7) DNA prevalence at diagnosis were assessed from whole peripheral blood samples, as well as EBV and CMV viral load and seroprevalence.

RESULTS

EBV DNA was significantly more prevalent in cases than in controls (50.8 vs 29.1 %; OR = 2.6; p = 0.0002), with no difference in viral load. A significant difference was also found for CMV (11.3 vs 3.6 %; p = 0.02) and HHV-7 (83 vs 72 %; p = 0.02) DNA prevalence between cases and controls. There were significantly more EBV and CMV recent infections or reactivations based on VCA-IgM and CMV IgM in cases than controls, while there were no differences in IgG seroprevalence.

CONCLUSION

The prevalence of positive EBV DNA detection and recent infection or reactivation is higher in children at onset of INS compared to a population matched for age, gender, and time of sampling.

Is cyclophosphamide effective in patients with IgM-positive minimal change disease?

BACKGROUND

We analyzed the impact of immunoglobulin M (IgM) positivity on the relapse-free interval post completed course of cyclophosphamide (CYC) treatment in patients with steroid-dependent nephrotic syndrome (SDNS) and minimal change disease (MCD).

METHODS

This was a retrospective chart review of all children who received CYC for SDNS and MCD between 1988 and 2009. Patients were divided into three groups based on kidney biopsy: MCD without immunoglobulin M (IgM) positivity (IgM-), MCD with IgM-positive immunofluorescence (IF) only (IgM+), and MCD with IgM-positive IF and electron-dense deposits on electron microscopy (IgM++). The relapse-free time interval to the first relapse post-CYC therapy or up to 48 months of follow-up (if no relapse occurred) was used for survival analysis.

RESULTS

Forty children aged 1.5-12.3 years (15 were IgM-, 16 were IgM+, 9 were IgM++) received a cumulative CYC dose of 175 ± 30 mg/kg. The overall relapse-free survival time was 75 % at 12 months, 64 % at 24 months, 59 % at 36 months, and 56 % at 48 months, with no significant differences between the IgM groups (p = 0.80).

CONCLUSIONS

Based on our results, we conclude that more than 50% of our SDNS patients with MCD remained relapse-free 4 years post-CYC treatment. No significant difference in the response to CYC was observed between patients with or without IgM positivity.

Mycophenolate mofetil for steroid-dependent nephrotic syndrome: a phase II Bayesian trial

Mycophenolate mofetil (MMF) has emerged as a new therapeutic option in steroid-dependent nephrotic syndrome (SDNS). We conducted a phase II Bayesian trial of MMF in children with SDNS. Phase II trials, usually single-arm studies, investigate the effect of new treatments. Standard Fleming's procedure relies on observed results (relapse rate during the trial), whereas Bayesian approach combines observed results with prior information (expected relapse rate according to prior studies and clinical experience). All patients were required to have received prior alkylating-agent treatment. Sixty-seven percent of them had also received levamisole. Patients received MMF (1,200 mg/m(2)/day) and prednisone according to a defined schedule [reduction of alternate-day (e.o.d) dose to 50% of pre-MMF dose at 3 months, 25% at 6 months]. Twenty-four children (median age 6.0 years, 2.8-14.4) entered the study and 23 completed it. Bayesian analysis showed that adding four patients would not change significance of results, allowing stopping inclusions. Four patients relapsed during the first 6 months (estimated probability 17.6%, 95% credibility interval: 5.4-35.0%) and two at months 8 and 11.5. In the 19 patients free of relapse during the first 6 months, median (Q1-Q3) prednisone maintenance dose decreased from 25 (10-44) to 9 (7.5-11.2) mg/m(2) e.o.d (p < 0.001) and cumulative dose from 459 (382-689) to 264 (196-306) mg/m(2)/month (p < 0.001) before and on MMF respectively. Pre-MMF patient characteristics and MMF pharmacokinetics did not differ between patients with or without relapse. MMF reduces relapse rate and steroid dose in children with SDNS and should be proposed before cyclosporine and cyclophosphamide.