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Finn LS. Nephrotic Syndrome Throughout Childhood: Diagnosing Podocytopathies From the Womb to the Dorm. Pediatr Dev Pathol 2024:10935266241242669. [PMID: 38745407 DOI: 10.1177/10935266241242669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The etiologies of podocyte dysfunction that lead to pediatric nephrotic syndrome (NS) are vast and vary with age at presentation. The discovery of numerous novel genetic podocytopathies and the evolution of diagnostic technologies has transformed the investigation of steroid-resistant NS while simultaneously promoting the replacement of traditional morphology-based disease classifications with a mechanistic approach. Podocytopathies associated with primary and secondary steroid-resistant NS manifest as diffuse mesangial sclerosis, minimal change disease, focal segmental glomerulosclerosis, and collapsing glomerulopathy. Molecular testing, once an ancillary option, has become a vital component of the clinical investigation and when paired with kidney biopsy findings, provides data that can optimize treatment and prognosis. This review focuses on the causes including selected monogenic defects, clinical phenotypes, histopathologic findings, and age-appropriate differential diagnoses of nephrotic syndrome in the pediatric population with an emphasis on podocytopathies.
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Affiliation(s)
- Laura S Finn
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at The University of Pennsylvania, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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2
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Shao Q, Xie X, Geng J, Yang X, Li W, Zhang Y. Frasier Syndrome: A 15-Year-Old Phenotypically Female Adolescent Presenting with Delayed Puberty and Nephropathy. CHILDREN 2023; 10:children10030577. [PMID: 36980135 PMCID: PMC10046944 DOI: 10.3390/children10030577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 03/19/2023]
Abstract
Frasier syndrome (FS) is a rare inherited disorder characterized by gonadal dysgenesis and progressive nephropathy, resulting from mutations in the intron 9 splice donor site of the Wilms tumor 1 (WT1) gene. It is associated with male gonadal dysgenesis (female external genitalia with a 46 XY karyotype), and a high risk of gonadoblastoma during adolescence. Patients with FS present early in childhood with proteinuria that progressively worsens with a high likelihood of end-stage renal disease (ESRD). Herein, we report a 15-year-old female (karyotype 46, XY) patient characterized by delayed puberty and steroid-resistant nephrotic syndrome, in whom whole genome sequencing showed a mutation in intron 9 of the WT1 gene, c.1447 + 4 C>T. This is the first case of FS with delayed puberty as the first complaint with no previous renal symptoms. We consider delayed puberty as an important manifestation of FS and summarize the diagnostic process of delayed puberty in the female phenotype. For clinicians, delayed puberty is a common disorder in pediatrics but requires vigilance for some rare causes. Etiological screening and chromosome karyotype analysis are important for the early diagnosis of FS in patients with delayed puberty.
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Affiliation(s)
- Qing Shao
- Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Xinglei Xie
- Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Jia Geng
- Institute of Rare Diseases, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Xiaoling Yang
- Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Wei Li
- Outpatient Department, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yuwei Zhang
- Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu 610041, China
- Correspondence:
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3
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Krendel M, Leh S, Garone ME, Edwards-Richards A, Lin JJ, Brackman D, Knappskog P, Mikhailov A. Focal segmental glomerulosclerosis and proteinuria associated with Myo1E mutations: novel variants and histological phenotype analysis. Pediatr Nephrol 2023; 38:439-449. [PMID: 35723736 PMCID: PMC10506584 DOI: 10.1007/s00467-022-05634-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 05/08/2022] [Accepted: 05/11/2022] [Indexed: 01/10/2023]
Abstract
BACKGROUND Pathogenic mutations in the non-muscle single-headed myosin, myosin 1E (Myo1e), are a rare cause of pediatric focal segmental glomerulosclerosis (FSGS). These mutations are biallelic, to date only reported as homozygous variants in consanguineous families. Myo1e regulates the actin cytoskeleton dynamics and cell adhesion, which are especially important for podocyte functions. METHODS DNA and RNA sequencing were used to identify novel MYO1E variants associated with FSGS. We studied the effects of these variants on the localization of Myo1e in kidney sections. We then analyzed the clinical and histological observations of all known pathogenic MYO1E variants. RESULTS We identified a patient compound heterozygote for two novel variants in MYO1E and a patient homozygous for a deletion of exon 19. Computer modeling predicted these variants to be disruptive. In both patients, Myo1e was mislocalized. As a rule, pathogenic MYO1E variants map to the Myo1e motor and neck domain and are most often associated with steroid-resistant nephrotic syndrome in children 1-11 years of age, leading to kidney failure in 4-10 years in a subset of patients. The ultrastructural features are the podocyte damage and striking diffuse and global Alport-like glomerular basement membrane (GBM) abnormalities. CONCLUSIONS We hypothesize that MYO1E mutations lead to disruption of the function of podocyte contractile actin cables resulting in abnormalities of the podocytes and the GBM and dysfunction of the glomerular filtration barrier. The characteristic clinicopathological data can help to tentatively differentiate this condition from other genetic podocytopathies and Alport syndrome until genetic testing is done. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Mira Krendel
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Sabine Leh
- Department of Pathology, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Michael E Garone
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | | | - Jen-Jar Lin
- Department of Pediatrics, Wake Forest Baptist Medical Center, Winston-Salem, NC, USA
| | - Damien Brackman
- Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Per Knappskog
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Alexei Mikhailov
- Department of Pathology, Atrium Health Wake Forest Baptist Medical Center, Winston-Salem, NC, USA.
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Anderson E, Aldridge M, Turner R, Harraway J, McManus S, Stewart A, Borzi P, Trnka P, Burke J, Coman D. WT1 complete gonadal dysgenesis with membranoproliferative glomerulonephritis: case series and literature review. Pediatr Nephrol 2022; 37:2369-2374. [PMID: 35211794 PMCID: PMC9395477 DOI: 10.1007/s00467-022-05421-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Intronic WT1 mutations are usually causative of Frasier syndrome with focal segmental glomerulosclerosis as the characteristic nephropathy. Membranoproliferative glomerulonephritis is not commonly associated with disorders of sex development but has been recently identified as a WT1-associated nephropathy, but usually in cases of exonic mutations in either isolated Wilms tumor or Denys-Drash syndrome. METHODS The clinical and genetic data from 3 individuals are reported. RESULTS This report describes the kidney manifestations in 3 individuals from 2 unrelated families with Frasier syndrome intronic WT1 mutations, noting that 2 of the 3 individuals have histologically confirmed membranoproliferative glomerulonephritis. CONCLUSIONS These case reports support expansion of the clinical spectrum of the kidney phenotypes associated with Frasier syndrome providing evidence of an association between WT1 mutation and an immune complex-related membranoproliferative glomerulonephritis. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Erin Anderson
- Queensland Fertility Group, Virtus Genetics, Brisbane, Australia
| | - Melanie Aldridge
- Department of Nephrology, The Queensland Children’s Hospital, Brisbane, Australia
| | - Ross Turner
- Monash IVF, The Wesley Hospital, Brisbane, Australia
| | - James Harraway
- Mater Pathology, The Mater Hospital, Brisbane, Australia
| | - Sam McManus
- Mater Pathology, The Mater Hospital, Brisbane, Australia
| | - Anna Stewart
- Department of Anatomical Pathology, The Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Peter Borzi
- Department of Paediatric Surgery and Urology, The Queensland Children’s Hospital, Brisbane, Australia ,Department of Paediatrics, The Wesley Hospital, Brisbane, Australia ,The School of Medicine, The University of Queensland, Brisbane, Australia
| | - Peter Trnka
- Department of Nephrology, The Queensland Children’s Hospital, Brisbane, Australia ,The School of Medicine, The University of Queensland, Brisbane, Australia
| | - John Burke
- Department of Nephrology, The Queensland Children’s Hospital, Brisbane, Australia ,The School of Medicine, The University of Queensland, Brisbane, Australia
| | - David Coman
- Queensland Fertility Group, Virtus Genetics, Brisbane, Australia. .,Department of Paediatrics, The Wesley Hospital, Brisbane, Australia. .,The School of Medicine, The University of Queensland, Brisbane, Australia. .,Department of Metabolic Medicine, The Queensland Children's Hospital, 501 Stanley Street, South Brisbane, QLD, 4101, Australia. .,The School of Medicine, Griffith University, Gold Coast, Australia.
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5
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Fujita M, Aizawa T, Tsugawa K, Mattinzoli D, Nozu K, Joh K, Tanaka H. Underrecognized Frasier syndrome revisited: Paradoxical immunocomplex deposition. Pediatr Int 2022; 64:e15350. [PMID: 36421979 DOI: 10.1111/ped.15350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/22/2022] [Accepted: 08/31/2022] [Indexed: 01/05/2023]
Affiliation(s)
- Masashi Fujita
- Department of Pediatrics, Hirosaki University Hospital, Hirosaki, Japan
| | - Tomomi Aizawa
- Department of Pediatrics, Hirosaki University Hospital, Hirosaki, Japan
| | - Koji Tsugawa
- Department of Pediatrics, Hirosaki University Hospital, Hirosaki, Japan
| | - Deborah Mattinzoli
- Department of Pediatrics, Renal Research Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kensuke Joh
- Department of Pathology, The Jikei Medical University, Tokyo, Japan
| | - Hiroshi Tanaka
- Department of Pediatrics, Hirosaki University Hospital, Hirosaki, Japan.,Department of School Health Science, Hirosaki University Faculty of Education, Hirosaki, Japan
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Tsuji Y, Yamamura T, Nagano C, Horinouchi T, Sakakibara N, Ishiko S, Aoto Y, Rossanti R, Okada E, Tanaka E, Tsugawa K, Okamoto T, Sawai T, Araki Y, Shima Y, Nakanishi K, Nagase H, Matsuo M, Iijima K, Nozu K. Systematic Review of Genotype-Phenotype Correlations in Frasier Syndrome. Kidney Int Rep 2021; 6:2585-2593. [PMID: 34622098 PMCID: PMC8484119 DOI: 10.1016/j.ekir.2021.07.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 12/22/2022] Open
Abstract
Introduction Frasier syndrome (FS) is a rare inherited kidney disease caused by intron 9 splicing variants of WT1. For wild-type WT1, 2 active splice donor sites in intron 9 cause a mixture of 2 essential transcripts (with or without lysine-threonine-serine [+/KTS or −KTS]), and imbalance of the +KTS/−KTS ratio results in the development of FS. To date, 6 causative intron 9 variants have been identified; however, detailed transcript analysis has not yet been conducted and the genotype-phenotype correlation also remains to be elucidated. Methods We conducted an in vitro minigene splicing assay for 6 reported causative variants and in vivo RNA sequencing to determine the +KTS/−KTS ratio using patients’ samples. We also performed a systematic review of reported FS cases with a description of the renal phenotype. Results The in vitro assay revealed that although all mutant alleles produced −KTS transcripts only, the wild-type allele produced both +KTS and −KTS transcripts at a 1:1 ratio. In vivo RNA sequencing showed that patients’ samples with all heterozygous variants produced similar ratios of +KTS to −KTS (1:3.2−1:3.5) and wild-type kidney showed almost a 1:1 ratio (1:0.85). A systematic review of 126 cases clarified that the median age of developing ESKD was 16 years in all FS patients, and there were no statistically significant differences between the genotypes or sex chromosome karyotypes in terms of the renal survival period. Conclusion Our study suggested no differences in splicing pattern or renal survival period among reported intron 9 variants causative of FS.
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Affiliation(s)
- Yurika Tsuji
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomohiko Yamamura
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - China Nagano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomoko Horinouchi
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Nana Sakakibara
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shinya Ishiko
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yuya Aoto
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Rini Rossanti
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Eri Okada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Eriko Tanaka
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Japan
| | - Koji Tsugawa
- Department of Pediatrics, Hirosaki University Hospital, Hirosaki, Japan
| | - Takayuki Okamoto
- Department of Pediatrics, Hokkaido University Graduate School of Meidicine, Sapporo, Japan
| | - Toshihiro Sawai
- Department of Pediatrics, Shiga University of Medical Science, Shiga, Japan
| | - Yoshinori Araki
- Department of Pediatrics, Hokkaido Medical Center, Sapporo, Japan
| | - Yuko Shima
- Department of Pediatrics, Wakayama Medical University, Wakayama, Japan
| | - Koichi Nakanishi
- Department of Child Health and Welfare (Pediatrics), Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Hiroaki Nagase
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Masafumi Matsuo
- Locomotion Biology Research Center, Kobe Gakuin University, Kobe, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
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Yamashita M, Lin MY, Hou J, Ren KY, Haas M. The Continuing Need for Electron Microscopy in Examination of Medical Renal Biopsies: Examples in Practice. GLOMERULAR DISEASES 2021; 1:145-159. [PMID: 36751496 PMCID: PMC9677721 DOI: 10.1159/000516831] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/23/2021] [Indexed: 12/24/2022]
Abstract
Background For the better part of the past 6 decades, transmission electron microscopy (EM), together with routine light microscopy and immunofluorescence and/or immunohistochemistry (IHC), has been an essential component of the diagnostic workup of medical renal biopsies, particularly native renal biopsies, with increasing frequency in renal allograft biopsies as well. Studies performed prior to the year 2000 have indeed shown that a substantial fraction of renal biopsies cannot be accurately diagnosed without EM. Still, EM remains costly and labor-intensive, and with increasing pressure to reduce healthcare costs, some centers are de-emphasizing diagnostic EM. This trend has been coupled with advances in IHC and other methods in renal biopsy diagnosis over the past 2-3 decades. Summary Nonetheless, it has been our experience that the diagnostic value of EM in the comprehensive evaluation of renal biopsies remains similar to what it was 20-30 years ago. In this review, we provide several key examples from our practice where EM was essential in making the correct renal biopsy diagnosis, ranging from relatively common glomerular lesions to rare diseases. Key Messages EM remains an important component of the diagnostic evaluation of medical renal biopsies. Failure to perform EM in certain cases will result in an incorrect diagnosis, with possible clinical consequences. We strongly recommend that tissue for EM be taken and stored in an appropriate fixative and ultrastructural studies be performed for all native renal biopsies, as well as appropriate renal allograft biopsies as recommended by the Banff consortium.
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Lusco MA, Fogo AB. Hereditary Nephritis and Thin Glomerular Basement Membrane Lesion. GLOMERULAR DISEASES 2021; 1:135-144. [PMID: 36751492 PMCID: PMC9677744 DOI: 10.1159/000516744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 04/21/2021] [Indexed: 11/19/2022]
Abstract
Hereditary nephritis (HN) and thin glomerular basement membrane (GBM) lesion share a common clinical presentation of persistent hematuria, thin GBM by kidney biopsy electron microscopic examination, and a mutation in type IV collagen. However, the clinical course and treatment for these entities are different with varying patterns of heredity. Ultrastructural examination of a renal biopsy specimen is essential for the morphologic diagnosis of HN and thin GBM lesion, whereas light microscopy may only give limited diagnostic clues. Additional workup including immunostaining for subtypes of type IV collagen may provide further information on underlying genetic mutations. The diagnosis of HN may lead to treatment with renin-angiotensin system blockade in patients at risk of early-onset renal failure to delay progression to end-stage renal disease. Additionally, patients with isolated microscopic hematuria and thin GBM lesion are at increased risk for chronic kidney disease when associated with other comorbidities; those patients should receive regular clinical assessment to prevent renal function decline.
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Matsuoka D, Noda S, Kamiya M, Hidaka Y, Shimojo H, Yamada Y, Miyamoto T, Nozu K, Iijima K, Tsukaguchi H. Immune-complex glomerulonephritis with a membranoproliferative pattern in Frasier syndrome: a case report and review of the literature. BMC Nephrol 2020; 21:362. [PMID: 32838737 PMCID: PMC7446187 DOI: 10.1186/s12882-020-02007-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 08/03/2020] [Indexed: 11/16/2022] Open
Abstract
Background Mutations in the Wilms tumor 1 gene cause a spectrum of podocytopathy ranging from diffuse mesangial sclerosis to focal segmental glomerulosclerosis. In a considerable fraction of patients with Wilms tumor 1 mutations, the distinctive histology of immune-complex-type glomerulonephritis has been reported. However, the clinical relevance and etiologic mechanisms remain unknown. Case presentation A 5-year-old child presented with steroid-resistant nephrotic range proteinuria. Initial renal biopsy revealed predominant diffuse mesangial proliferation with a double-contour and coexisting milder changes of focal segmental glomerulosclerosis. Immunofluorescence and electron microscopy revealed a full-house-pattern deposition of immune complexes in the subendothelial and paramesangial areas. Serial biopsies at 6 and 8 years of age revealed that more remarkable changes of focal segmental glomerulosclerosis had developed on top of the initial proliferative glomerulonephritis. Identification of a de novo Wilms tumor 1 splice donor-site mutation in intron 9 (NM_024426.6:c.1447 + 4C > T) and 46,XY-gonadal dysgenesis led to the diagnosis of Frasier syndrome. Conclusions Our findings, together with those of others, point to the importance of heterogeneity in clinicopathological phenotypes caused by Wilms tumor 1 mutations and suggest that immune-complex-mediated membranoproliferative glomerulopathy should be considered as a histological variant.
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Affiliation(s)
- Daisuke Matsuoka
- Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Shunsuke Noda
- Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.,Department of Pediatrics, Nagano Red Cross Hospital, Nagano, Japan
| | - Motoko Kamiya
- Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.,Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan
| | - Yoshihiko Hidaka
- Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan
| | | | - Yasushi Yamada
- Department of Obstetrics and Gynecology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Tsutomu Miyamoto
- Department of Obstetrics and Gynecology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroyasu Tsukaguchi
- Second Department of Internal Medicine, Division of Nephrology, Kansai Medical University, 2-5-1 Shinmachi Hirakata, Osaka, 573-1191, Japan.
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Arslansoyu Camlar S, Ünlü M, Soylu A, Karaca D, Sarioglu S, Kavukcu S. Contribution of Electron Microscopy to the Clinicopathologic Diagnosis in Childhood Glomerular Renal Diseases. Fetal Pediatr Pathol 2019; 38:299-306. [PMID: 30942128 DOI: 10.1080/15513815.2019.1587119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Background: Electron microscopy (EM) provides another diagnostic assessment of glomerular lesions in addition to light and fluorescent microscopy. Objectives: We evaluated the contribution of diagnostic EM in childhood glomerular diseases. Patients and methods: Forty-eight renal biopsies which were assessed by EM between 2000 and 2014 were evaluated. Results: There were 21 (44%) females and 27 (56%) males, ages ranged between 6 and 204 months. EM findings were compatible with light and immunofluorescence microscopy in 65%, made additional contributions to diagnosis in 31% (especially in focal segmental glomerulosclerosis, Alport disease, membranoproliferative glomerulonephritis, dense deposit disease, thin basement membrane disease, and nephronophthisis), and was non-contributory in 4%. Conclusion: Electron microscopic evaluation supports other histopathological diagnoses in most cases, contributes additional diagnostic information in pediatric glomerular disease, especially in FSGS, thin glomerular basement membrane nephropathy, Alport disease, MPGN, and dense deposit disease, and its utilization should clinically justify the increase in cost and testing time.
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Affiliation(s)
- Secil Arslansoyu Camlar
- a Department of Pediatrics, Division of Nephrology, Dokuz Eylul Universitesi Tip Fakultesi , Izmir 35210 , Turkey
| | - Mehtat Ünlü
- b Department of Pathology, Dokuz Eylul Universitesi Tip Fakultesi , Izmir 35210 , Turkey
| | - Alper Soylu
- a Department of Pediatrics, Division of Nephrology, Dokuz Eylul Universitesi Tip Fakultesi , Izmir 35210 , Turkey
| | - Duygu Karaca
- c Department of Pediatrics, Dokuz Eylul Universitesi Tip Fakultesi , Izmir 35210 , Turkey
| | - Sulen Sarioglu
- b Department of Pathology, Dokuz Eylul Universitesi Tip Fakultesi , Izmir 35210 , Turkey
| | - Salih Kavukcu
- a Department of Pediatrics, Division of Nephrology, Dokuz Eylul Universitesi Tip Fakultesi , Izmir 35210 , Turkey
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11
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Nagata M. Podocyte injury and its consequences. Kidney Int 2016; 89:1221-30. [PMID: 27165817 DOI: 10.1016/j.kint.2016.01.012] [Citation(s) in RCA: 327] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 12/12/2015] [Accepted: 01/27/2016] [Indexed: 01/02/2023]
Abstract
Podocytes maintain the glomerular filtration barrier, and the stability of this barrier depends on their highly differentiated postmitotic phenotype, which also defines the particular vulnerability of the glomerulus. Recent podocyte biology and gene disruption studies in vivo indicate a causal relationship between abnormalities of single podocyte molecules and proteinuria and glomerulosclerosis. Podocytes live under various stresses and pathological stimuli. They adapt to maintain homeostasis, but excessive stress leads to maladaptation with complex biological changes including loss of integrity and dysregulation of cellular metabolism. Podocyte injury causes proteinuria and detachment from the glomerular basement membrane. In addition to "sick" podocytes and their detachment, our understanding of glomerular responses following podocyte loss needs to address the pathways from podocyte injury to sclerosis. Studies have found a variety of glomerular responses to podocyte dysfunction in vivo, such as disruption of podocyte-endothelial cross talk and activation of podocyte-parietal cell interactions, all of which help us to understand the complex scenario of podocyte injury and its consequences. This review focuses on the cellular aspects of podocyte dysfunction and the adaptive or maladaptive glomerular responses to podocyte injury that lead to its major consequence, glomerulosclerosis.
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Affiliation(s)
- Michio Nagata
- Kidney and Vascular Pathology, University of Tsukuba, Ibaraki, Japan.
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12
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Baek H, Lee SI, Park T, Cho M. The Transition from Thin Basement Membranes to Typical Alport Syndrome Morphology in Children. Fetal Pediatr Pathol 2016; 35:369-375. [PMID: 27410722 DOI: 10.1080/15513815.2016.1202362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Some children with thin basement membranes (TBM) turn out to have Alport syndrome (AS). In our population of 58 children initially diagnosed with TBM, three were eventually diagnosed with AS. As a group, these three were first biopsied at a younger age, and had gross rather than microscopic hematuria. Only one had lamellations initially. Seven others had some degree of basement membrane lamellations at initial biopsy, but none of these have developed other features of AS. We concluded that at least 5% of children initially demonstrating TBM go on to manifest the classical electron-microscopic findings of AS during childhood. Episodes of gross hematuria with TBM can be a significant clue of AS. Genetic and/or immunofluorescent studies for type IV collagen, and continued long-term follow-up should be done in all children with TBM.
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Affiliation(s)
- Heesun Baek
- a Department of Pediatrics , Kyungpook National University School of Medicine , Daegu , Republic of Korea
| | - Sang-In Lee
- a Department of Pediatrics , Kyungpook National University School of Medicine , Daegu , Republic of Korea
| | - Taein Park
- b Department of Pathology , Kyungpook National University School of Medicine , Daegu , Republic of Korea
| | - Minhyun Cho
- a Department of Pediatrics , Kyungpook National University School of Medicine , Daegu , Republic of Korea
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14
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Springate J, Nadasdy T. Unusual histological findings in a child with idiopathic nephrotic syndrome. Pediatr Nephrol 2007; 22:451-3. [PMID: 17077973 DOI: 10.1007/s00467-006-0330-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Revised: 08/04/2006] [Accepted: 08/24/2006] [Indexed: 11/25/2022]
Abstract
We report a 2-year-old child with corticosteroid-resistant nephrotic syndrome whose renal biopsy revealed light microscopically normal glomeruli but highly unusual finger-like projections and arches of the glomerular basement membrane. To our knowledge, the association between nephrotic syndrome and this patient's rare ultrastuctural lesion has not been previously documented in the literature. It is not certain whether this basement membrane is pathogenic or a striking but coincidental developmental anomaly.
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Affiliation(s)
- James Springate
- Department of Pediatrics, School of Medicine and Biomedical Sciences, State University of New York, and Division of Nephrology, Women and Children's Hospital, Buffalo, NY, 14214, USA.
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15
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Aucella F, Bisceglia L, De Bonis P, Gigante M, Caridi G, Barbano G, Mattioli G, Perfumo F, Gesualdo L, Ghiggeri GM. WT1 mutations in nephrotic syndrome revisited. High prevalence in young girls, associations and renal phenotypes. Pediatr Nephrol 2006; 21:1393-8. [PMID: 16909243 DOI: 10.1007/s00467-006-0225-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Revised: 05/09/2006] [Accepted: 05/09/2006] [Indexed: 11/29/2022]
Abstract
WT1 mutations have been considered a rare cause of nephrotic syndrome but recent reports challenge this assumption. Exclusion of inherited forms is a basic point in any therapeutic strategy to nephrotic syndrome since they do not respond to drugs. We screened for WT1 mutations in 200 patients with nephrotic syndrome: 114 with steroid resistance (SRNS) and 86 with steroid dependence (SDNS) for whom other inherited forms of nephrotic syndrome (NPHS2, CD2AP) had been previously excluded. Three girls out of 32 of the group with steroid resistance under 18 years presented classical WT1 splice mutations (IVS9+5G>A, IVS9+4C>T) of Frasier syndrome. Another one presented a mutation coding for an amino acid change (D396N) at exon 9 that is typical of Denys-Drash syndrome. All presented resistance to drugs and developed end stage renal failure within 15 years. Two girls of the Frasier group presented a 46 XY karyotype with streak gonads while one was XX and had normal gonad morphology. In the two cases with IVS9+5G>A renal pathology was characterized by capillary wall thickening with deposition of IgG and C3 in one that was interpreted as a membrane pathology. Foam cells were diffuse in tubule-interstitial areas. In conclusion, WT1 splice mutations are not rare in females under 18 years with SRNS. This occurs in absence of a clear renal pathology picture and frequently in absence of phenotype change typical of Frasier syndrome. In adults and children with SDNS, screening analysis is of no clinical value. WT1 hot spot mutation analysis should be routinely done in children with SRNS; if the molecular screening anticipates any further therapeutic approach it may modify the long term therapeutic strategy.
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Affiliation(s)
- Filippo Aucella
- Nephrology Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
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16
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Choi JH, Na KS, Bae SH, Roh GH. Anterior lens capsule abnormalities in Alport syndrome. KOREAN JOURNAL OF OPHTHALMOLOGY 2005; 19:84-9. [PMID: 15929494 DOI: 10.3341/kjo.2005.19.1.84] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Alport syndrome is a hereditary, progressive disease characterized by progressive nephritis, sensorineural deafness, and ocular abnormalities, including anterior lenticonus. The ultrastructure of the lens capsule abnormalities in Alport syndrome is reported. Four anterior lens capsules from 31-year-old patient and 26-year-old patient with lenticonus who were affected by the Alport syndrome were obtained at capsulectomy. And all four anterior lens capsules were examined by transmission electron microscopy. The histopathologic findings showed that the thickness of the anterior lens capsules was decreased (4-13 microm) and that there were many vascular dehiscences localized at the inner part of the lens capsule. There were large numbers of capsular dehiscences containing fibrillar materials and vacuoles. The anterior capsules were clearly fragile in this disease, forming the basis for the progressive lenticonus and anterior polar cataract.
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Affiliation(s)
- Jae hyuk Choi
- Department of Ophthalmology, College of Medicine, Konyang University, Myung Gok Eye Research Institute, Daejeon, Korea
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