Hiroshi Hataya

The Impact of Repeated Subclinical Acute Rejection on the Progression of Chronic Allograft Nephropathy

Chronic allograft nephropathy (CAN) is due to both immunologic and non-immunologic factors and results in the development of nonspecific pathologic features that may even be present in long-term well-functioning renal allografts. To investigate the natural history of CAN and potential risk factors associated with progression of these histologic lesions, this study evaluated the of histologic alterations of 124 sequential protocol biopsies performed at 2, 3, and 5 yr after transplantation in 46 patients who exhibited histologic evidence of CAN in the 1-yr biopsy. The occurrence of late acute rejection (AR) greater than 4 mo posttransplant was significantly associated with the development of histologic CAN. In contrast, early clinical AR occurring within 3 mo had no impact on the subsequent development of CAN at 1 yr. Subclinical AR was evident in association with CAN in 50%, 32%, 19%, and 16% of cases with CAN at 1, 2, 3, and 5 yr, respectively. These acute lesions correlated significantly with histologic progression defined as an increased CADI score of the follow-up biopsies. Furthermore, a group of patients who exhibited repeated subclinical AR in the sequential follow-up biopsies had a lower creatinine clearance at 5 yr after transplantation and worse long-term graft survival. In contrast, the absence of evidence of acute inflammation in association with CAN at any time point was associated with minimal deterioration in renal function or progression of renal lesions during the observation period. These results suggest that the persistence of chronic active inflammation may be responsible for the histologic progression of CAN.

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.

Reversible posterior leukoencephalopathy in a patient with minimal-change nephrotic syndrome

A 9-year-old boy with nephrotic syndrome was transferred to our hospital because of acute renal failure and disturbance of consciousness after high-dose methylprednisolone therapy. He developed severe headache, visual disturbance, and generalized seizures. Brain computed tomography (CT) scan revealed multiple, bilateral, low-density areas in the parieto-occipital lobes. Magnetic resonance imaging (MRI) disclosed a high signal intensity area on T2-weighted images and a low signal intensity area on T1-weighted images in the same lesion. Follow-up brain CT scan and MRI, 2 weeks after the first studies, showed complete resolution of the abnormal lesions, which suggested the diagnosis of reversible posterior leukoencephalopathy syndrome (RPLS). Hypertension and high-dose methylprednisolone administration to the patient in the nephrotic state may be causes of this uncommon syndrome in this case. This is the first report of RPLS in nephrotic syndrome with hypertension not associated with cyclosporine administration.

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.

Two-Year Outcome of the ISKDC Regimen and Frequent-Relapsing Risk in Children with Idiopathic Nephrotic Syndrome

BACKGROUND AND OBJECTIVES Early identification of frequently relapsing children with idiopathic nephrotic syndrome is desirable. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The relapse status and clinical data of patients previously registered (January of 1993 to December of 2001) in a multicenter prospective study of the International Study of Kidney Disease in Children regimen were analyzed for risk of frequent relapsers over a 2-year follow-up period. RESULTS Of 166 children with nephrotic syndrome (113 boys and 53 girls; median age=5.1 years), 145 (87.3%, median age=5.5 years) children were steroid-sensitive, and 21 (12.7%, median age=2.9 years) children were steroid-resistant. Of 145 children with steroid-sensitive nephrotic syndrome, 32 (22.1%, median age=4.2 years) children experienced frequent relapses over 2 years. The time to initial response was significantly longer (10 versus 7 days, P<0.001, log-rank test) in the 32 frequent relapsers than in the 106 nonfrequent relapsers. The time from start of initial treatment to first relapse was significantly shorter (2.6 versus 6.1 months, P<0.001, log-rank test) in the 32 frequent relapsers than in the 57 infrequent relapsers. In a Cox regression model, the time to initial response ≥9 days and the duration from start of initial treatment to first relapse <6 months were significant predictors of frequent relapses (unadjusted and adjusted). CONCLUSIONS Initial remission time ≥9 days and first relapse within 6 months were associated with frequent relapses. These findings may also be useful also in selecting potential frequent relapsers for clinical trials.

Japanese Society for Dialysis Therapy Clinical Guideline for “Hemodialysis Initiation for Maintenance Hemodialysis”

Yuzo Watanabe, Kunihiro Yamagata, Shinichi Nishi, Hideki Hirakata, Norio Hanafusa, Chie Saito, Motoshi Hattori, Noritomo Itami, Yasuhiro Komatsu, Yoshindo Kawaguchi, Kazuhiko Tsuruya, Yoshiharu Tsubakihara, Kazuyuki Suzuki, Ken Sakai, Hideki Kawanishi, Daijo Inaguma, Hiroyasu Yamamoto, Yoshiaki Takemoto, Noriko Mori, Kazuyoshi Okada, Hiroshi Hataya, Takashi Akiba, Kunitoshi Iseki, Tadashi Tomo, Ikuto Masakane, Tadao Akizawa, and Jun Minakuchi, for “Hemodialysis Initiation for Maintenance Hemodialysis” Guideline Working Group, Japanese Society for Dialysis Therapy

Diagnostic criteria for atypical hemolytic uremic syndrome proposed by the Joint Committee of the Japanese Society of Nephrology and the Japan Pediatric Society.

Atypical hemolytic uremic syndrome (aHUS) is rare and comprises the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. Recently, abnormalities in the mechanisms underlying complement regulation have been focused upon as causes of aHUS. The prognosis for patients who present with aHUS is very poor, with the first aHUS attack being associated with a mortality rate of approximately 25%, and with approximately 50% of cases resulting in end‐stage renal disease requiring dialysis. If treatment is delayed, there is a high risk of this syndrome progressing to renal failure. Therefore, we have developed diagnostic criteria for aHUS to enable its early diagnosis and to facilitate the timely initiation of appropriate treatment. We hope these diagnostic criteria will be disseminated to as many clinicians as possible and that they will be used widely.