Kenji Ishikura

Rituximab for childhood-onset, complicated, frequently relapsing nephrotic syndrome or steroid-dependent nephrotic syndrome: a multicentre, double-blind, randomised, placebo-controlled trial

BACKGROUND Rituximab could be an effective treatment for childhood-onset, complicated, frequently relapsing nephrotic syndrome (FRNS) and steroid-dependent nephrotic syndrome (SDNS). We investigated the efficacy and safety of rituximab in patients with high disease activity. METHODS We did a multicentre, double-blind, randomised, placebo-controlled trial at nine centres in Japan. We screened patients aged 2 years or older experiencing a relapse of FRNS or SDNS, which had originally been diagnosed as nephrotic syndrome when aged 1-18 years. Patients with complicated FRNS or SDNS who met all other criteria were eligible for inclusion after remission of the relapse at screening. We used a computer-generated sequence to randomly assign patients (1:1) to receive rituximab (375 mg/m(2)) or placebo once weekly for 4 weeks, with age, institution, treatment history, and the intervals between the previous three relapses as adjustment factors. Patients, guardians, caregivers, physicians, and individuals assessing outcomes were masked to assignments. All patients received standard steroid treatment for the relapse at screening and stopped taking immunosuppressive agents by 169 days after randomisation. Patients were followed up for 1 year. The primary endpoint was the relapse-free period. Safety endpoints were frequency and severity of adverse events. Patients who received their assigned intervention were included in analyses. This trial is registered with the University Hospital Medical Information Network clinical trials registry, number UMIN000001405. FINDINGS Patients were centrally registered between Nov 13, 2008, and May 19, 2010. Of 52 patients who underwent randomisation, 48 received the assigned intervention (24 were given rituximab and 24 placebo). The median relapse-free period was significantly longer in the rituximab group (267 days, 95% CI 223-374) than in the placebo group (101 days, 70-155; hazard ratio: 0·27, 0·14-0·53; p<0·0001). Ten patients (42%) in the rituximab group and six (25%) in the placebo group had at least one serious adverse event (p=0·36). INTERPRETATION Rituximab is an effective and safe treatment for childhood-onset, complicated FRNS and SDNS. FUNDING Japanese Ministry of Health, Labour and Welfare.

The Lack of Cyclin Kinase Inhibitor p27Kip1 Ameliorates Progression of Diabetic Nephropathy

Cyclin kinase inhibitor p27(Kip(1)) (p27) has been shown to be upregulated in glomeruli of diabetic animals and mesangial cells cultured under high glucose. This study was an investigation of the role of p27 in the progression of diabetic nephropathy. Mice deficient in p27 (p27 -/-) and wild-type mice (p27 +/+) were studied 12 wk after diabetes induction by streptozotocin. Blood glucose and BP were comparable between diabetic p27 +/+ and p27 -/- mice. The kidney weight to body weight ratio and glomerular volume increased in diabetic p27 +/+ mice. In contrast, these parameters did not change in diabetic p27 -/- mice. Similarly, albuminuria developed in diabetic p27 +/+ mice but not in diabetic p27 -/- mice. The mesangial expansion was significantly milder in diabetic p27 -/- mice than that in diabetic p27 +/+ mice. These changes were associated with a similar increase in glomerular TGF-beta expression in diabetic p27 +/+ and p27 -/- mice. However, glomerular protein expression of fibronectin, a target of TGF-beta, increased only in diabetic p27 +/+ mice. In mesangial cells cultured from p27 +/+ mice, exposure to high glucose caused significant increases in total protein content and [(3)H]-leucine incorporation. On the other hand, high glucose caused a significant reduction in these parameters in cells from p27 -/- mice. Phosphorylation of 4E-BP1, the translation inhibitor, increased after exposure to high glucose in p27 +/+ cells. In p27 -/- cells, the level of phosphorylated 4E-BP1 was higher than that in control p27 +/+ cells and decreased under high glucose conditions. In conclusion, renal hypertrophy, glomerular hypertrophy, and albuminuria did not develop, and mesangial expansion was milder in diabetic p27 -/- mice despite glomerular TGF-beta upregulation. These results suggest that controlling p27 function may ameliorate diabetic nephropathy.

Effective and safe treatment with cyclosporine in nephrotic children: A prospective, randomized multicenter trial

We conducted a prospective, open-label multicenter trial to evaluate the efficacy and safety of treating children with frequently relapsing nephrotic syndrome with cyclosporine. Patients were randomly divided into two groups with both initially receiving cyclosporine for 6 months to maintain a whole-blood trough level between 80 and 100 ng/ml. Over the next 18 months, the dose was adjusted to maintain a slightly lower (60-80 ng/ml) trough level in Group A, while Group B received a fixed dose of 2.5 mg/kg/day. The primary end point was the rate of sustained remission with analysis based on the intention-to-treat principle. After 2 years, the rate of sustained remission was significantly higher while the hazard ratio for relapse was significantly lower in Group A as compared with Group B. Mild arteriolar hyalinosis of the kidney was more frequently seen in Group A than in Group B, but no patient was diagnosed with striped interstitial fibrosis or tubular atrophy. We conclude that cyclosporine given to maintain targeted trough levels is an effective and relatively safe treatment for children with frequently relapsing nephrotic syndrome.

Age, gender, and body length effects on reference serum creatinine levels determined by an enzymatic method in Japanese children : a multicenter study

BackgroundEnzymatic methods have recently been used to measure creatinine (Cr) instead of the Jaffe method. Therefore, it is necessary to determine the reference serum Cr value for these enzymatic methods to evaluate renal function in Japanese children.MethodsTo determine reference values of serum Cr in Japanese children, 1151 children (517 male, 634 female) aged between 1 month and 18 years had their serum Cr values measured by an enzymatic method. To be included in the study the children had to be without kidney disease, urogenital disease, infectious disease, inflammatory disease, dehydration, muscular disease, anomaly syndrome, cardiovascular disease, malignant disease, hypertension, liver or pancreas disease, or pregnancy.ResultsThe medians of reference values increased gradually with age, i.e., 0.30 mg/dl at 4 years old and 0.41 mg/dl at 10 years old. In adolescence, they increased significantly more rapidly in males than in females. We found a linear regression equation capable of estimating the reference value of serum Cr in children aged 2–11 years, and quintic regression equations capable of estimating the reference values of serum Cr in male and female children of all ages.ConclusionThe reference serum Cr levels determined by an enzymatic method related to age, gender, and body length, and our linear and polynomial equations showing the relationship between body length and serum Cr level will be applicable for screening of renal function in Asian as well as Japanese children.

Nephrotic state as a risk factor for developing posterior reversible encephalopathy syndrome in paediatric patients with nephrotic syndrome

BACKGROUND Posterior reversible encephalopathy syndrome (PRES) is a distinctive and potentially serious complication of the nephrotic syndrome. The objective of the present study is to characterize the factors predisposing the development of PRES in paediatric patients with nephrotic syndrome. METHODS We investigated paediatric patients with idiopathic nephrotic syndrome who developed PRES between 1999 and 2005 in our institution. Patients with steroid-sensitive nephrotic syndrome and those with steroid-resistant nephrotic syndrome that were proven to be idiopathic were eligible. RESULTS In total, seven patients ranging in age from 1.5 to 15.1 years old were analysed. At the onset of PRES, six of the seven patients were in a nephrotic state. Various degrees of acute renal insufficiency were shown in four patients. The re-administration of cyclosporine after the episodes of PRES was carried out in four patients. During the observation for 17-51 months after the re-administration, the recurrence of PRES did not develop in these patients. CONCLUSIONS The development of PRES occurred at the time of moderate to severe nephrotic state in most of our paediatric patients with nephrotic syndrome. Besides the administration of cyclosporine and having hypertension, there appear to be several additive factors predisposing the development of PRES in these patients, namely low serum albumin level, generalized oedema, increase in vascular permeability, unstable fluid status and renal insufficiency. The re-administration of cyclosporine to those patients with anamnesis of PRES may be considered after the management and close monitoring of these factors as well as hypertension.

A multicenter randomized trial indicates initial prednisolone treatment for childhood nephrotic syndrome for two months is not inferior to six-month treatment

In this multicenter, open-label, randomized controlled trial, we determined whether 2-month prednisolone therapy for steroid-sensitive nephrotic syndrome was inferior or not to 6-month therapy despite significantly less steroid exposure. The primary end point was time from start of initial treatment to start of frequently relapsing nephrotic syndrome. The pre-specified non-inferiority margin was a hazard ratio of 1.3 with one-sided significance of 5%. We randomly assigned 255 children with an initial episode of steroid-sensitive nephrotic syndrome to either 2 - or 6-month treatment of which 246 were eligible for final analysis. The total prednisolone exposure counted both initial and relapse prednisolone treatment administered over 24 months. Median follow-up in months was 36.7 in the 2-month and 38.2 in the 6-month treatment group. Time to frequent relaps was similar in both groups; however, the median was reached only in the 6-month group (799 days). The hazard ratio was 0.86 (90% confidence interval, 0.64–1.16) and met the non-inferior margin. Time to first relapse was also similar in both groups: median day 242 (2-month) and 243 (6-month). Frequency and severity of adverse events were similar in both groups. Most adverse events were transient and occurred during initial or relapse therapy. Thus, 2 months of initial prednisolone therapy for steroid-sensitive nephrotic syndrome, despite less prednisolone exposure, is not inferior to 6 months of initial therapy in terms of time to onset of frequently relapsing nephrotic syndrome.

Long-Term Results of a Randomized Controlled Trial in Childhood IgA Nephropathy

BACKGROUND AND OBJECTIVES Children with IgA nephropathy showing diffuse (>80%) mesangial proliferation are at high risk for end-stage renal failure (ESRF). A previous controlled trial showed that combination therapy consisting of prednisolone, azathioprine, heparin-warfarin, and dipyridamole early in the course of disease reduces immunologic renal injury and prevents the progression of sclerosed glomeruli. The objective of this study was to evaluate the long-term effectiveness of combination therapy in children with IgA nephropathy showing diffuse mesangial proliferation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A secondary analysis of a multicenter, randomized, controlled trial involving 78 children with IgA nephropathy who received either 2-year combination therapy or heparin-warfarin and dipyridamole (control) therapy was conducted. RESULTS The median duration of observation was 10 years (range, 0.5 to 18). Two of 40 patients (5%) who received combination therapy and five of 34 patients (14.7%) who received control therapy developed ESRF. A Kaplan-Meier plot of renal survival showed that the outcomes of patients in the combined therapy group were better than those in the control therapy group (log-rank P = 0.03). The 10-year renal survival probability of each group was 97.1% (95% confidence interval, 81.4 to 99.6%) and 84.8% (95% confidence interval, 55.4 to 95.5%), respectively. The Cox proportional hazards model showed that the 2-year combination therapy was significantly associated with renal survival in both univariate and multivariate analyses. CONCLUSIONS Two-year combination therapy not only ameliorated the activity of the acute phase of nephritis but also improved the long-term outcome of severe childhood IgA nephropathy.

Posterior reversible encephalopathy syndrome in children with kidney diseases

Posterior reversible encephalopathy syndrome (PRES) was originally used to describe a reversible, predominantly posterior leukoencephalopathy in patients who had renal insufficiency, hypertension, or who received immunosuppressive therapy. Since PRES is prevalent in children with kidney diseases, awareness and understanding of it is important for practicing pediatric nephrologists. A comprehensive approach to the diagnosis of PRES includes thorough determination of predisposing factors, clinical symptoms, and mandatory appropriate imaging. Unfortunately, the pathophysiology of PRES is still obscure and specificity of radiological examination has not yet been established. Two major predisposing factors, namely hypertension and calcineurin inhibitors, are well recognized. In addition, nephrotic syndrome is a common underlying condition for development of PRES. Frequent symptoms include altered consciousness (coma, stupor, lethargy, confusion), seizure, headache, and visual disturbance. Most of these symptoms usually develop abruptly and resolve within a few weeks after proper management. Cranial magnetic resonance (MR) imaging is the first-line modality of imaging studies for detecting PRES. Diffusion-weighted imaging with quantification of apparent diffusion coefficient (ADC) values by ADC mapping may provide more accurate and specific images in the future.

Treatment with microemulsified cyclosporine in children with frequently relapsing nephrotic syndrome

BACKGROUND We previously established a treatment protocol for conventional cyclosporine (Sandimmune, Novartis, Basel, Switzerland) in children with frequently relapsing nephrotic syndrome; ∼50% of patients remained relapse free for 2 years, without serious adverse events. Recently, microemulsified cyclosporine (Neoral, Novartis), which has a more stable absorption profile than conventional cyclosporine, has been developed. We tested the hypothesis that microemulsified cyclosporine is at least as effective as conventional cyclosporine. METHODS To evaluate the safety and efficacy of microemulsified cyclosporine, a prospective, multicentre trial was conducted according to the previously established protocol, using microemulsified cyclosporine instead of conventional cyclosporine. The duration of treatment was 24 months. During the first 6 months, patients received microemulsified cyclosporine in a dose that maintained the trough level between 80 and 100 ng/mL of cyclosporine. For the next 18 months, the dose was adjusted to maintain a level between 60 and 80 ng/mL. RESULTS A total of 62 patients (median age, 5.4 years; 48 males, 14 females) were studied. The frequency of relapse decreased from 4.6 ± 1.4 to 0.7 ± 1.5 times per year (P < 0.0001). The probability of relapse-free survival at Month 24 was 58.1% (95% confidence interval, 45.8-70.3%). The probability of progression (to frequently relapsing nephrotic syndrome)-free survival at Month 24 was 88.5% (95% confidence interval, 80.4-96.5%). Cyclosporine nephrotoxicity was detected in only 8.6% of patients who underwent renal biopsy after 2 years of treatment. Antihypertensive agents were administered to 12.9% of the patients to control hypertension without severe sequelae. CONCLUSIONS Microemulsified cyclosporine administered according to our treatment protocol is safe and effective in children with frequently relapsing nephrotic syndrome.

Pre-dialysis chronic kidney disease in children: results of a nationwide survey in Japan

BACKGROUND Chronic kidney disease (CKD) in children is a progressive and intractable condition that may severely impair the childs growth, development and quality of life. Epidemiological information on pediatric CKD, particularly in Asians, is scant. METHODS We conducted a nationwide, population-based survey of Japanese children aged 3 months to 15 years with pre-dialysis CKD to examine the prevalence of pediatric CKD in Japan. CKD was classified according to newly established criteria derived from reference serum creatinine levels in Japanese children. Surveys were sent to 1190 institutions across Japan to report on cases of pediatric CKD managed as of 1 April 2010. RESULTS A total of 925 institutions (77.7%) responded. Information on 447 children was collected. When subdivided according to our diagnostic criteria, 70.5% of children had stage 3 CKD, 23.9% stage 4 and 5.6% stage 5. The estimated prevalence of Japanese children with CKD was 2.98 cases/100,000 children. Of 407 CKD cases with non-glomerular disease, 278 (68.3%) had congenital anomalies of the kidney and urinary tract (CAKUT). The newly established criteria showed good validity compared with existing criteria, including the abbreviated Schwartz equation. CONCLUSIONS Findings from the first nationwide survey of pre-dialysis CKD in Asian children indicate that the prevalence of stage 3-5 CKD in children in Japan aged 3 months to 15 years is 2.98 cases/100,000 children. Most children with CKD presented with non-glomerular disease, most frequently CAKUT. Improved management of CAKUT, including renoprotective treatment and urological intervention, is required.