Kandai Nozu

Kobe University, Kōbe, Hyōgo, Japan

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Publications (97)351.52 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Some patients with childhood immunoglobulin A nephropathy (IgAN) progress to end-stage renal disease within 20 years, while others achieve spontaneous remission even without medication. Prognosis of IgAN with minimal proteinuria (MP-IgAN, <0.5 g/day/1.73 m(2)) at diagnosis seems to be generally good. However, the long-term outcome for patients with childhood MP-IgAN has not yet been determined. We retrospectively analyzed 385 children newly diagnosed with biopsy-proven IgAN between June 1976 and July 2009 whose renal biopsy specimens could be evaluated by the Oxford classification criteria. Of these 385 children with IgAN, 106 (27.5 %) were diagnosed with MP-IgAN. We compared clinical and pathological findings between the 106 patients with MP-IgAN and the remaining 279 patients to elucidate the characteristics of MP-IgAN in children. Patients with MP-IgAN were identified through a school screening program (73.6 %) or upon presentation with gross hematuria (26.4 %). Patients with MP-IgAN had significantly milder pathological symptoms than those with IgAN. The most frequently used therapeutic regimes were angiotensin converting enzyme inhibitors (30.2 %) and no therapy (36.8 %). None of the patients with MP-IgAN reached stage III chronic kidney disease within 15 years after onset. Four patients with MP-IgAN (3.8 %) received immunosuppressive therapy during the course of the disease. Our results indicate that the outcome of patients with a diagnosis of childhood MP-IgAN is good, but that careful long-term observation is required.
    Pediatric Nephrology 08/2015; DOI:10.1007/s00467-015-3176-5 · 2.88 Impact Factor
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    ABSTRACT: X-linked Alport syndrome (XLAS) is a progressive, hereditary nephropathy. Although men with XLAS usually develop end-stage renal disease before 30 years of age, some men show a milder phenotype and develop end-stage renal disease later in life. However, the molecular mechanisms associated with this milder phenotype have not been fully identified. We genetically diagnosed 186 patients with suspected XLAS between January 2006 and August 2014. Genetic examination involved: (1) extraction and analysis of genomic DNA using PCR and direct sequencing using Sanger's method and (2) next-generation sequencing to detect variant allele frequencies. We identified somatic mosaic variants in the type VI collagen, α5 gene (COL4A5) in four patients. Interestingly, two of these four patients with variant frequencies in kidney biopsies or urinary sediment cells of ≥50% showed hematuria and moderate proteinuria, whereas the other two with variant frequencies of <50% were asymptomatic or only had hematuria. De novo variants can occur even in asymptomatic male cases of XLAS resulting in mosaicism, with important implications for genetic counseling. This is the first study to show a tendency between the variant allele frequency and disease severity in male XLAS patients with somatic mosaic variants in COL4A5. Although this is a very rare status of somatic mosaicism, further analysis is needed to show this correlation in a larger population.European Journal of Human Genetics advance online publication, 27 May 2015; doi:10.1038/ejhg.2015.113.
    European journal of human genetics: EJHG 05/2015; DOI:10.1038/ejhg.2015.113 · 4.23 Impact Factor
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    ABSTRACT: Phenotypic overlap exists among type III Bartter syndrome (BS), Gitelman syndrome (GS), and pseudo-BS/GS (p-BS/GS), which are clinically difficult to distinguish. We aimed to clarify the differences between these diseases, allowing accurate diagnosis based on their clinical features. A total of 163 patients with genetically defined type III BS (n = 30), GS (n = 90), and p-BS/GS (n = 43) were included. Age at diagnosis, sex, body mass index, estimated glomerular filtration rate, and serum and urine electrolyte concentrations were determined. Patients with p-BS/GS were significantly older at diagnosis than those with type III BS and GS. Patients with p-BS/GS included a significantly higher percentage of women and had a lower body mass index and estimated glomerular filtration rate than did patients with GS. Although hypomagnesemia and hypocalciuria were predominant biochemical findings in patients with GS, 17 and 23% of patients with type III BS and p-BS/GS, respectively, also showed these abnormalities. Of patients with type III BS, GS, and p-BS/GS, 40, 12, and 63%, respectively, presented with chronic kidney disease. This study clarified the clinical differences between BS, GS, and p-BS/GS for the first time, which will help clinicians establish differential diagnoses for these three conditions.Genet Med advance online publication 16 April 2015Genetics in Medicine (2015); doi:10.1038/gim.2015.56.
    Genetics in medicine: official journal of the American College of Medical Genetics 04/2015; DOI:10.1038/gim.2015.56 · 6.44 Impact Factor
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    ABSTRACT: CDKL5-related encephalopathy is an X-linked dominantly inherited disorder that is characterized by early infantile epileptic encephalopathy or atypical Rett syndrome. We describe a 5-year-old Japanese boy with intractable epilepsy, severe developmental delay, and Rett syndrome-like features. Onset was at 2months, when his electroencephalogram showed sporadic single poly spikes and diffuse irregular poly spikes. We conducted a genetic analysis using an Illumina® TruSight™ One sequencing panel on a next-generation sequencer. We identified two epilepsy-associated single nucleotide variants in our case: CDKL5 p.Ala40Val and KCNQ2 p.Glu515Asp. CDKL5 p.Ala40Val has been previously reported to be responsible for early infantile epileptic encephalopathy. In our case, the CDKL5 heterozygous mutation showed somatic mosaicism because the boy's karyotype was 46,XY. The KCNQ2 variant p.Glu515Asp is known to cause benign familial neonatal seizures-1, and this variant showed paternal inheritance. Although we believe that the somatic mosaic CDKL5 mutation is mainly responsible for the neurological phenotype in the patient, the KCNQ2 variant might have some neurological effect. Genetic analysis by next-generation sequencing is capable of identifying multiple variants in a patient. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
    Brain & development 03/2015; DOI:10.1016/j.braindev.2015.03.002 · 1.54 Impact Factor
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    Kazumoto Iijima · Mayumi Sako · Kandai Nozu
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    ABSTRACT: In the past 10 years, many reports have suggested that rituximab, a chimeric anti-CD20 monoclonal antibody, is effective for children with complicated, frequently relapsing or steroid-dependent nephrotic syndrome (FRNS/SDNS). However, those reports were case reports, case series, retrospective surveys, and single-arm or short-term trials. Therefore, well-designed controlled trials are required to establish the value of rituximab in this condition. To evaluate the efficacy and safety of rituximab in childhood-onset, complicated FRNS/SDNS, a multicenter, double-blind, randomized, placebo-controlled trial was carried out by the Research Group of Childhood-onset Refractory Nephrotic Syndrome (RCRNS) in Japan (RCRNS01). RCRNS01 showed that rituximab is safe and effective for the treatment of childhood-onset, complicated FRNS/SDNS. In 2014, the use of rituximab for patients with complicated FRNS/SDNS was approved, first in the world, by the Ministry of Health, Labour and Welfare, Japan.
    03/2015; 3(1). DOI:10.1007/s40124-014-0065-5
  • The Lancet 01/2015; 385(9964). DOI:10.1016/S0140-6736(15)60052-6 · 45.22 Impact Factor
  • Nippon Jinzo Gakkai shi 01/2015; 57(4):743-50.
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    ABSTRACT: Although a 2-year combination therapy is effective for severe childhood immunoglobulin A (IgA) nephropathy, proteinuria persists in some patients even after the treatment. Seventy-nine patients aged <18 years with IgA nephropathy in which >80 % of glomeruli showed mesangial proliferation were enrolled in the study. Risk factors for persistent proteinuria after combination therapy were investigated using multivariate logistic regression analysis. Proteinuria (≥0.2 g/1.73 m(2)/day) persisted in 27 patients (34 %) after the combination therapy. Twenty-four-hour urinary protein excretion, rate of glomeruli with crescents, rate of glomeruli with segmental sclerosis and rate of glomeruli with global sclerosis at diagnosis were higher in patients with persistent proteinuria than those without. In the multivariate analysis, 24-h urinary protein excretion [odds ratio (OR) 6.9; 95 % confidence interval (CI) 2.1-27.8; p = 0.001] and rate of glomeruli with crescents (OR 3.8; 95 % CI 1.1-13.9; p = 0.03) were independent risk factors for persistent proteinuria. Analysis of the receiver operating characteristic curve demonstrated that the most accurate cut-off values to detect persistent proteinuria were a urinary protein excretion of 1.32 g/1.73 m(2)/day and a 14 % rate of glomeruli with crescents. In our cohort, urinary protein excretion and rate of glomeruli with crescents at diagnosis were independent risk factors for persistent proteinuria after the combination therapy.
    Pediatric Nephrology 12/2014; 30(6). DOI:10.1007/s00467-014-3019-9 · 2.88 Impact Factor
  • Pediatric Nephrology 12/2014; 29(12):2443-2443. · 2.88 Impact Factor
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    ABSTRACT: 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/m2) 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 Lancet 10/2014; 384(9950). DOI:10.1016/S0140-6736(14)60541-9 · 45.22 Impact Factor
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    ABSTRACT: Microdeletion of 16q12 is a rare chromosomal abnormality. We present the cases of two Japanese patients with developmental and renal symptoms of differing clinical severity. Both patients had 16q12 interstitial microdeletions that included the entire SALL1 gene. Patient 1 was a 15-year-old Japanese boy clinically diagnosed with branchio-oto-renal syndrome with mild developmental delay, but with no imperforate anus or polydactyly. Array comparative genome hybridization (aCGH) indicated a 5.2 Mb deletion in 16q12, which included SALL1. Patient 2 was a 13-year-old Japanese boy diagnosed with Townes–Brocks syndrome and severe developmental delay, epilepsy, and renal insufficiency requiring renal replacement therapy. Fluorescence in situ hybridization indicated deletion of the entire SALL1 gene. Subsequent aCGH showed a 6 Mb deletion in 16q12q13, which included SALL1. Precise analysis of the present two cases will give us some clues to elucidate the pathogenic mechanisms of 16q12 microdeletion syndrome.
    Pediatrics International 10/2014; 56(5). DOI:10.1111/ped.12426 · 0.73 Impact Factor
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    ABSTRACT: X-linked Alport syndrome is caused by mutations in the COL4A5 gene. Although many COL4A5 mutations have been detected, the mutation detection rate has been unsatisfactory. Some men with X-linked Alport syndrome show a relatively mild phenotype, but molecular basis investigations have rarely been conducted to clarify the underlying mechanism.
    Clinical Journal of the American Society of Nephrology 09/2014; 9(11). DOI:10.2215/CJN.04140414 · 5.25 Impact Factor
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    ABSTRACT: Mutation-induced activation of splice sites in intronic repetitive sequences has contributed significantly to the evolution of exon–intron structure and genetic disease. Such events have been associated with mutations within transposable elements, most frequently in mutation hot-spots of Alus. Here, we report a case of Alu exonization resulting from a 367-nt genomic COL4A5 deletion that did not encompass any recognizable transposed element, leading to the Alport syndrome. The deletion brought to proximity the 5′ splice site of COL4A5 exon 33 and a cryptic 3′ splice site in an antisense AluY copy in intron 32. The fusion exon was depleted of purines and purine-rich splicing enhancers, but had low levels of intramolecular secondary structure, was flanked by short introns and had strong 5′ and Alu-derived 3′ splice sites, apparently compensating poor composition and context of the new exon. This case demonstrates that Alu splice sites can be activated by outlying deletions, highlighting Alu versatility in shaping the exon–intron organization and expanding the spectrum of mutational mechanisms that introduce repetitive sequences in mRNAs.
    09/2014; 2(5). DOI:10.1002/mgg3.89
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    ABSTRACT: Background The criterion for performing a renal biopsy in children with idiopathic nephrotic syndrome (NS) showing microscopic hematuria at onset remains controversial. Methods To determine an adequate renal biopsy criterion in children with NS showing hematuria, the optimal cutoff for the maximum red blood cell (RBC) range in urine sediment to separate minimal change disease (MCD) from other glomerular changes was obtained by receiver operating characteristic analysis. We studied 29 children with NS showing hematuria who were screened from 1,320 patients who underwent renal biopsies between January 2001 and September 2011. Patients were divided into two groups according to the cutoff value to verify its validity. Results The optimal maximum RBC range was 30-49/high-power field (HPF). In group 1 (RBC ≤29/HPF, n = 14), 3 patients showed nephritis and the other 11 patients showed MCD. In group 2 (RBC ≥30/HPF, n = 15), 1 patient showed focal segmental glomerulosclerosis, 12 showed nephritis, and the other 2 showed MCD. These findings indicated that the ratio of non-MCD/MCD was significantly higher in group 2 than in group 1 (P Conclusions The use of maximum RBC range (30-49/HPF) for a criterion of renal biopsy in patients with NS showing hematuria may be reasonable for clinical practice.
    Pediatric Nephrology 08/2014; 30(3). DOI:10.1007/s00467-014-2946-9 · 2.88 Impact Factor
  • 08/2014; 1:14006. DOI:10.1038/hgv.2014.6
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    ABSTRACT: 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.Kidney International advance online publication, 23 July 2014; doi:10.1038/ki.2014.260.
    Kidney International 07/2014; DOI:10.1038/ki.2014.260 · 8.52 Impact Factor
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    ABSTRACT: Background Although the Oxford classification of IgA nephropathy appears valid, we found crescents were significantly related to renal outcome in our cohort, whereas segmental glomerulosclerosis (S) was not. The timing of renal biopsy may significantly affect the variables in the Oxford classification. Method The relationship between biopsy timing and pathological variables (mesangial hypercellularity score [M], endocapillary hypercellularity [E], S, tubular atrophy/interstitial fibrosis [T], crescents, and global glomerulosclerosis [G]) was analyzed retrospectively in 250 children with IgA nephropathy. Results The median time from disease onset to renal biopsy was 5.1 months (interquartile range, 2.7–15.4). M (ρ = −0.26, P
    Pediatric Nephrology 06/2014; 30(2). DOI:10.1007/s00467-014-2862-z · 2.88 Impact Factor
  • Naoya Morisada · Kandai Nozu · Kazumoto Iijima
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    ABSTRACT: Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by branchiogenic malformation, hearing loss and renal anomalies. The prevalence of BOR syndrome is 1/40,000 in Western countries, and nationwide surveillance in 2009–2010revealed that there were approximately 250 BOR patients in Japan. Three causative genes for BOR syndrome have been reported thus far:EYA1, SIX1, and SIX5.However, the causative genes for approximately half of all BOR patients remain unknown. This review article discusses the epidemiology, clinical symptoms, genetic background and management of BOR syndrome.
    Pediatrics International 04/2014; 56(3). DOI:10.1111/ped.12357 · 0.73 Impact Factor
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    ABSTRACT: Autosomal recessive Alport syndrome (ARAS) is a rare hereditary disease caused by homozygous or compound heterozygous mutations in either the COL4A3 or COL4A4 genes. Failure to diagnose ARAS cases is common, even if detailed clinical and pathological examinations are carried out. As the mutation detection rate for ARAS is unsatisfactory, we sought to develop more reliable diagnostic methods and provide a better description of the clinicopathological characteristics of this disorder. A retrospective analysis of 30 genetically diagnosed patients with ARAS in 24 pedigrees was conducted. The mutation detection strategy comprised three steps: (1) genomic DNA analysis using polymerase chain reaction (PCR) and direct sequencing; (2) mRNA analysis using reverse transcription (RT)-PCR to detect RNA processing abnormalities; (3) semi-quantitative PCR using capillary electrophoresis to detect large heterozygous deletions. Using the three-step analysis, we identified homozygous or compound heterozygous mutations in all patients. Interestingly, 20 % of our ARAS patients showed normal expression of α5 in kidney tissue. The median age of developing end-stage renal disease was 21 years. The strategy described in this study improves the diagnosis for ARAS families. Although immunohistochemical analysis of α5 can provide diagnostic information, normal distribution does not exclude the diagnosis of ARAS.
    Pediatric Nephrology 03/2014; 29(9). DOI:10.1007/s00467-014-2797-4 · 2.88 Impact Factor
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    ABSTRACT: X-linked Alport syndrome is caused by mutations in the COL4A5 gene encoding the type IV collagen α5 chain (α5(IV)). Complete absence of α5(IV) in the renal basal membrane is considered a pathological characteristic in male patients; however, positive α5(IV) staining has been found in over 20% of patients. We retrospectively studied 52 genetically diagnosed male X-linked Alport syndrome patients to evaluate differences in clinical characteristics and renal outcomes between 15 α5(IV)-positive and 37 α5(IV)-negative patients. Thirteen patients in the α5(IV)-positive group had non-truncating mutations consisting of nine missense mutations, three in-frame deletions, and one splice-site mutation resulting in small in-frame deletions of transcripts. The remaining two showed somatic mutations with mosaicism. Missense mutations in the α5(IV)-positive group were more likely to be located before exon 25 compared with missense mutations in the α5(IV)-negative group. Furthermore, urinary protein levels were significantly lower and the age at onset of end-stage renal disease was significantly higher in the positive group than in the negative group. These results help to clarify the milder clinical manifestations and molecular characteristics of male X-linked Alport syndrome patients expressing the α5(IV) chain.Kidney International advance online publication, 4 December 2013; doi:10.1038/ki.2013.479.
    Kidney International 12/2013; 85(5). DOI:10.1038/ki.2013.479 · 8.52 Impact Factor

Publication Stats

900 Citations
351.52 Total Impact Points

Institutions

  • 2008–2014
    • Kobe University
      • Division of Pediatrics
      Kōbe, Hyōgo, Japan
  • 2011
    • Medical College of Wisconsin
      • Department of Pediatrics
      Milwaukee, Wisconsin, United States
  • 2006–2011
    • Wakayama Medical University
      • Department of Pediatrics
      Wakayama, Wakayama, Japan