Yuko Hamasaki

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.

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.

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.

Clinical practice guideline for pediatric idiopathic nephrotic syndrome 2013: general therapy

Nephrotic syndrome is a disorder characterized by severe proteinuria, hypoproteinemia, and generalized edema resulting from damage to the glomerular basement membrane. In Western countries, nephrotic syndrome affects 2 of 100,000 children per year [1]. In Japan, approximately 1,300 new cases per year of pediatric nephrotic syndrome are reported to the Medical Aid for Specific Chronic Disease of Children and the disease develops in 5 of 100,000 children per year. Approximately 90 % of the cases of pediatric nephrotic syndrome are idiopathic, or of unknown cause. The first-line treatment for an initial episode of pediatric idiopathic nephrotic syndrome is oral steroid therapy, which leads to remission in approximately 80 % of cases (steroidsensitive nephrotic syndrome) [2]. However, 80 % of children with steroid-sensitive nephrotic syndrome experience one or more relapses, [3] and 50 % of these children have frequent relapses [4]. Those with frequently relapsing nephrotic syndrome are prone to suffer steroid-induced side effects such as obesity, growth impairment, hypertension, diabetes mellitus, osteoporosis, and adrenal insufficiency. Many cases of steroid-resistant nephrotic syndrome, where steroids are ineffective, progress to renal failure. Pediatric idiopathic nephrotic syndrome is a very important disease in the field of pediatric nephrology. The Scientific Committee in the Japanese Society for Pediatric Nephrology previously published the ‘‘Clinical Practice Guideline for Pediatric Idiopathic Nephrotic Syndrome’’ (2013). This is the English translation from the ‘‘Medical Therapy’’ portion of the guideline.Nephrotic syndrome is a disorder characterized by severe proteinuria, hypoproteinemia, and generalized edema resulting from damage to the glomerular basement membrane. In Western countries, nephrotic syndrome affects 2 of 100,000 children per year [1]. In Japan, approximately 1,300 new cases per year of pediatric nephrotic syndrome are reported to the Medical Aid for Specific Chronic Disease of Children and the disease develops in 5 of 100,000 children per year. Approximately 90 % of the cases of pediatric nephrotic syndrome are idiopathic, or of unknown cause. The first-line treatment for an initial episode of pediatric idiopathic nephrotic syndrome is oral steroid therapy, which leads to remission in approximately 80 % of cases (steroidsensitive nephrotic syndrome) [2]. However, 80 % of children with steroid-sensitive nephrotic syndrome experience one or more relapses, [3] and 50 % of these children have frequent relapses [4]. Those with frequently relapsing nephrotic syndrome are prone to suffer steroid-induced side effects such as obesity, growth impairment, hypertension, diabetes mellitus, osteoporosis, and adrenal insufficiency. Many cases of steroid-resistant nephrotic syndrome, where steroids are ineffective, progress to renal failure. Pediatric idiopathic nephrotic syndrome is a very important disease in the field of pediatric nephrology. The Scientific Committee in the Japanese Society for Pediatric Nephrology previously published the ‘‘Clinical Practice Guideline for Pediatric Idiopathic Nephrotic Syndrome’’ (2013). This is the English translation from the ‘‘Medical Therapy’’ portion of the guideline.

Progression to end-stage kidney disease in Japanese children with chronic kidney disease: results of a nationwide prospective cohort study

BACKGROUND The risk of progressing to end-stage kidney disease (ESKD) and factors associated with progression in children with chronic kidney disease (CKD) are unclear, especially in Asian children. METHODS We started a nationwide, prospective cohort study of 447 Japanese children with pre-dialysis CKD in 2010, with follow-up in 2011. Progression to ESKD was analyzed by Kaplan-Meier analysis according to CKD stage. Cox regression analysis was used to identify risk factors for progression. RESULTS Data were analyzed for 429/447 children. Five patients died, of which four died before progression to ESKD. Fifty-two patients progressed to ESKD (median follow-up 1.49 years), including 9/315 patients with stage 3 CKD, 29/107 with Stage 4 CKD and 14/25 with Stage 5 CKD. One-year renal survival rates were 98.3, 80.0 and 40.9%, for Stages 3, 4 and 5 CKD, respectively. Risk factors for progression to ESKD included CKD stage [versus Stage 3; Stage 4: hazard ratio (HR) 11.12, 95% confidence interval (CI) 4.22-29.28, P < 0.001; Stage 5: HR 26.95, 95% CI 7.71-94.17, P < 0.001], heavy proteinuria (>2.0 g/g urine creatinine; HR 7.56, 95% CI 3.22-17.77, P < 0.001) and age ( < 2 years: HR 9.06; 95% CI 2.29-35.84, P = 0.002; after starting puberty: HR 4.88; 95% CI 1.85-12.85, P = 0.001). CONCLUSIONS In this cohort, 12.5% of children with pre-dialysis CKD progressed to ESKD with a median-follow-up of 1.49 years. Children with advanced (Stage 4/5) CKD were particularly likely to progress. To our knowledge, this is the first, nationwide, prospective cohort study of children with pre-dialysis CKD in Asia.

Unexpectedly high prevalence of pretransplant abnormal glucose tolerance in pediatric kidney transplant recipients

Abstract:  Several studies suggested that the incidence of new‐onset diabetes following pediatric kidney transplantation has increased markedly in recent years, with reported incidence of up to 20%. However, limited information is available regarding the incidence and features of pretransplant status of abnormal glucose tolerance in pediatric kidney transplant recipients. We assessed the risk of 55 non‐diabetic pediatric transplant recipients developing PTDM by performing OGTT prior to transplantation. For post‐transplant immunosuppression, each patient received either a CsA‐ or a TAC‐based regimen. However, recipients who had abnormal glucose tolerance in the pretransplant OGTT were allocated to the CsA‐based regimen. The mean age of the patients was 9.7 ± 5.4 yr while mean BMI was 16.5 ± 3.3 kg/m2. FPG level before transplantation was within the normal limit in all patients, while the mean HbA1C value was 4.5. However, 18 of the 55 patients (32.7%) had abnormal glucose tolerance in the pretransplant OGTT, 13 (23.6%) had impaired glucose tolerance, and 5 (9.4%) had DM. PTDM developed in two patients on the TAC‐based regimen with these patients having normal glucose tolerance prior to the transplant. In contrast, the 18 patients with abnormal glucose tolerance did not develop PTDM under CsA‐based immunosuppression. Our results demonstrated an unexpectedly high prevalence of abnormal glucose tolerance in pretransplant OGTT even in a pediatric population. We believe that modification of post‐transplant immunosuppression by the identification of high‐risk patients using the pretransplant OGTT may minimize the development of new onset of PTDM.

Children with posterior reversible encephalopathy syndrome associated with atypical diffusion-weighted imaging and apparent diffusion coefficient

Posterior reversible encephalopathy syndrome (PRES) is a reversible, predominantly posterior, leukoencephalopathy associated with renal insufficiency, hypertension, or immunosuppressant drugs. We describe two children with PRES whose primary diagnoses were idiopathic nephrotic syndrome and lupus nephritis. Cranial magnetic resonance (MR) imaging at the onset of PRES showed strong hyperintense signals on diffusion-weighted imaging with restricted apparent diffusion coefficient values predominantly in the posterior region. Such findings have been rarely reported in children with PRES and initially suggested irreversible brain damage; however, both children fully recovered clinically as well as radiologically. Our findings suggest the limitations of cranial MR imaging for diagnosing PRES. Further experience with cranial MR imaging, including diffusion-weighted imaging with apparent diffusion coefficient mapping, is required to improve diagnostic accuracy and the ability to predict outcomes in patients with early-stage PRES. At present, initial imaging studies do not necessarily provide sufficient evidence for a firm diagnosis of PRES or the prediction of outcomes.

Combination of pulse methylprednisolone infusions with cyclosporine-based immunosuppression is safe and effective to treat recurrent focal segmental glomerulosclerosis after pediatric kidney transplantation

Recurrence of focal segmental glomerulosclerosis (FSGS) in pediatric kidney allografts is associated with poor graft survival. Several therapeutic regimens have been proposed, with conflicting results.

Proteinuria during Follow-Up Period and Long-Term Renal Survival of Childhood IgA Nephropathy.

Background Proteinuria is the most important risk factor for IgA nephropathy progression. The purpose of this study is to evaluate the long-term outcome and risk factors for poor prognosis in childhood IgA nephropathy. Methods Patients who were diagnosed with IgA nephropathy between 1972 and 1992 at the Tokyo Metropolitan Kiyose Children’s Hospital were included. We analyzed risk factors for progression to end-stage kidney disease (ESKD) and chronic renal insufficiency (CRI) using Kaplan-Meier method and multivariate analyses of Cox proportional hazard model. Results One hundred patients were included and the median observation period was 11.8 years. Twelve and 17 patients progressed to ESKD and CRI, respectively. The survival probabilities were 90.0% at 10 years and 79.8% at 20 years for ESKD, and 86.1% at 10 years and 72.3% at 20 years for CRI. Notably, patients with heavy proteinuria with hypoalbuminemia during follow-up period showed extremely poor prognosis. In this group, the survival rate at 10 years from ESKD and CRI was 40.6% and 20.8%, respectively. By multivariate analysis, proteinuria at diagnosis and proteinuria during follow-up period were risk factors for ESKD, whereas glomeruli showing mesangial proliferation ≥50% and proteinuria during follow-up period were risk factors for CRI. Patients without heavy proteinuria during follow-up period did not develop CRI and 63% of patients with mild proteinuria during follow-up period showed no proteinuria at the last observation. Conclusions The degree of proteinuria during follow-up period is the strongest risk factor for ESKD and CRI.

An infantile case of Hinman syndrome with severe acute renal failure

A 1-year-6-month-old Japanese girl with Hinman syndrome manifested urosepsis and severe obstructive nephropathy. Her voiding cystourethrogram (VCUG) revealed high-grade vesicoureteral reflux with hydronephrosis; urodynamic study was compatible with detrusor-sphincter dyssynergia. She was treated conservatively, including clean intermittent catheterization. At 3 years old, bladder function had not improved, and estimated creatinine clearance was in the subnormal range. Hinman syndrome is a potential cause of acute and chronic renal failure in infancy. Taking account of the possibility of this condition in any neonates or infants who present urinary tract infection (UTI) appears to be necessary, since early recognition and proper management of this syndrome may prevent serious complications.