1
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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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Nieto-Gañán I, Iturrieta-Zuazo I, Rita C, Carrasco-Sayalero Á. Revisiting immunological and clinical aspects of membranous nephropathy. Clin Immunol 2022; 237:108976. [PMID: 35276323 DOI: 10.1016/j.clim.2022.108976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 02/16/2022] [Accepted: 03/05/2022] [Indexed: 11/29/2022]
Abstract
Idiopathic or primary membranous nephropathy (IMN) is one of the most frequent causes of nephrotic syndrome in adults and the elderly. It is characterized by a thickening of the wall of the glomerular capillaries due to the presence of immune complex deposits. 85% of membranous nephropathy cases are classified as primary or idiopathic (IMN). The rest are of secondary origin (SMN), caused by autoimmune conditions or malignant tumors as lung cancer, colon and melanomas. It is an organ-specific autoimmune disease in which the complement system plays an important role with the formation of the membrane attack complex (MAC; C5b-9), which produces an alteration of the podocyte structure. The antigen responsible for 70-80% of IMN is a podocyte protein called M-type phospholipase A2 receptor (PLA2R). More recently, another podocyte antigen has been identified, the "Thrombospondin type-1 domain-containing 7A" (THSD7A), which is responsible for 10% of the cases of negative IMN for anti- PLA2R.
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Affiliation(s)
- Israel Nieto-Gañán
- Immunology Department, Hospital Universitario Ramón y Cajal, Madrid, Spain.
| | - Ignacio Iturrieta-Zuazo
- Immunology Department, Hospital Universitario Ramón y Cajal, Madrid, Spain; Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Spain
| | - Claudia Rita
- Immunology Department, Hospital Universitario Ramón y Cajal, Madrid, Spain
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3
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Nugent JT, Reardon J, Crana C, Greenberg JH, Warejko JK, Goodwin JE. Fanconi syndrome, nephrotic-range proteinuria, and hypoalbuminemia in a newborn-Occam's razor or Hickam's dictum? Answers. Pediatr Nephrol 2022; 37:129-132. [PMID: 34633532 DOI: 10.1007/s00467-021-05255-w] [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: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 11/26/2022]
Affiliation(s)
- James T Nugent
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA.
| | - Juliann Reardon
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Christine Crana
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Jason H Greenberg
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Jillian K Warejko
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Julie E Goodwin
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
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4
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AbuMaziad AS, Abusaleh R, Bhati S. Congenital nephrotic syndrome. J Perinatol 2021; 41:2704-2712. [PMID: 34983935 DOI: 10.1038/s41372-021-01279-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 06/24/2021] [Accepted: 11/15/2021] [Indexed: 11/09/2022]
Abstract
Congenital nephrotic syndrome (CNS), a challenging form of nephrotic syndrome, is characterized by massive proteinuria, hypoalbuminemia, and edema. Extensive leakage of plasma proteins is the main feature of CNS. Patients can be diagnosed in utero or during the first few weeks of life, usually before three months. The etiology of CNS can be related to either genetic or nongenetic etiologies. Pathogenic variants in NPHS1, NPHS2, LAMB2, WT1, and PLCE1 genes have been implicated in this disease. The clinical course is complicated by significant edema, infections, thrombosis, hypothyroidism, failure to thrive, and others. Obtaining vascular access, frequent intravenous albumin infusions, diuretic use, infection prevention, and nutritional support are the mainstay management during their first month of life. The best therapy for these patients is kidney transplantation. CNS diagnosis and treatment continue to be a challenge for clinicians. This review increases the awareness about the pathogenesis, diagnosis, and management of CNS patients.
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Affiliation(s)
- Asmaa S AbuMaziad
- Department of Pediatrics, Division of Nephrology, University of Arizona, Tucson, AZ, USA.
| | - Rami Abusaleh
- Department of Pediatrics, Division of Nephrology, University of Arizona, Tucson, AZ, USA
| | - Shanti Bhati
- Department of Pediatrics, Division of Nephrology, University of Arizona, Tucson, AZ, USA
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5
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Nortier JL, Remiche G, Delrée P, Nauta J, Notermans NC, Vivarelli M, Diodato D, Solé G, Debiec H, Ronco P. Antenatal Membranous Nephropathy and Type 2 (Axonal) Charcot-Marie-Tooth With Mutations in the Metallo-Membrane Endopeptidase Gene: A Call for Family Screening and Pharmacovigilance. Kidney Int Rep 2021; 6:1981-1986. [PMID: 34307994 PMCID: PMC8258500 DOI: 10.1016/j.ekir.2021.04.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 04/19/2021] [Indexed: 11/25/2022] Open
Affiliation(s)
- Joëlle L Nortier
- Nephrology Department, CHU Brugmann, Université libre de Bruxelles, Brussels, Belgium
| | - Gauthier Remiche
- Neurology Department, Centre de Référence Neuromusculaire Erasme-HUDERF, Hôpital Erasme, Université libre de Bruxelles, Brussels, Belgium
| | - Paul Delrée
- Pathology Department, Institute of Pathology and Genetics, Gosselies, Belgium
| | - Jeroen Nauta
- Department of Pediatric Nephrology, Erasmus MC, Sophia Childrens Hospital, Rotterdam, The Netherlands
| | | | - Marina Vivarelli
- U.O. Nefrologia e Dialisi, Children's Hospital Bambino Gesù, IRCCS, Roma, Italy
| | - Daria Diodato
- Neuromuscular and Neurodegenerative Diseases Unit, Children Research, Children's Hospital Bambino Gesù, IRCCS, Roma, Italy
| | - Guilhem Solé
- Centre de référence des maladies neuromusculaires AOC, Pellegrin Hospital, Bordeaux, France
| | - Hanna Debiec
- Sorbonne Université, Inserm UMR_S1155, Tenon Hospital, Paris, France
| | - Pierre Ronco
- Sorbonne Université, Inserm UMR_S1155, Tenon Hospital, Paris, France.,Nephrology Department, Centre Hospitalier du Mans, Le Mans, France
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6
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Dupuis M, Raymackers JM, Ackermans N, Boulanger S, Verellen-Dumoulin C. Hereditary axonal neuropathy related to MME gene mutation in a family with fetomaternal alloimmune glomerulonephritis. Acta Neurol Belg 2020; 120:149-154. [PMID: 31974930 DOI: 10.1007/s13760-020-01275-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 01/07/2020] [Indexed: 12/11/2022]
Abstract
We report a consanguineous family with a homozygous and heterozygous membrane metallo-endopeptidase (MME) mutation (c.467delC) and two clinical conditions: fetomaternal alloimmune membranous glomerulopathy (FMG) and hereditary motor and sensory axonal neuropathy. The penetrance of both phenotypes was variable. Some individuals experienced unusually fast neurological degradation. Pain and vasomotor signs were frequent complaints, possibly due to a loss of the neutral endopeptidase (NEP, the MME gene product) function and its subsequent inability to degrade substance P and vasomotor peptides. Electrophysiological and nerve biopsy findings were consistent with predominantly axonal neuropathy. This specific clinical phenotype was attributed to a c.467delC MME gene mutation. Diagnosis of such a mutation is important but can be challenging, due to allele dropout. Heterozygous subjects who had already reached the expected age of disease onset had peripheral neuropathy, but also suffered from additional diseases. Neurologists should advise women of childbearing age with MME mutations to seek pre-pregnancy genetic advice and nephrologists should search for neuropathy in patients with FMG.
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Affiliation(s)
- M Dupuis
- Department of Neurology and Neurosurgery, Clinique Saint-Pierre, 9 avenue Reine Fabiola, B-1340, Ottignies, Belgium
- Institute of Pathology and Genetics, 25 avenue Georges Lemaître, B-6041, Charleroi, Belgium
| | - J M Raymackers
- Department of Neurology and Neurosurgery, Clinique Saint-Pierre, 9 avenue Reine Fabiola, B-1340, Ottignies, Belgium.
| | - N Ackermans
- Department of Neurology and Neurosurgery, Clinique Saint-Pierre, 9 avenue Reine Fabiola, B-1340, Ottignies, Belgium
| | - S Boulanger
- Institute of Pathology and Genetics, 25 avenue Georges Lemaître, B-6041, Charleroi, Belgium
| | - C Verellen-Dumoulin
- Institute of Pathology and Genetics, 25 avenue Georges Lemaître, B-6041, Charleroi, Belgium
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7
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Ronco P, Debiec H. Molecular Pathogenesis of Membranous Nephropathy. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2019; 15:287-313. [PMID: 31622560 DOI: 10.1146/annurev-pathol-020117-043811] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membranous nephropathy is a noninflammatory autoimmune disease of the kidney glomerulus, characterized by the formation of immune deposits, complement-mediated proteinuria, and risk of renal failure. Considerable advances in understanding the molecular pathogenesis have occurred with the identification of several antigens [neutral endopeptidase, phospholipase A2 receptor (PLA2R), thrombospondin domain-containing 7A (THSD7A)] in cases arising from the neonatal period to adulthood and the characterization of antibody-binding domains (that is, epitopes). Immunization against PLA2R occurs in 70% to 80% of adult cases. The development of highly specific and sensitive assays of circulating antibodies has induced a paradigm shift in diagnosis and treatment monitoring. In addition, several interacting loci in HLA-DQ, HLA-DR, and PLA2R1, as well as classical human leukocyte antigen (HLA)-D alleles have been identified as being risk factors, depending on a patient's ethnicity. Additionally, mechanisms of antibody pathogenicity and pathways of complement activation are now better understood. Further research is mandatory for designing new therapeutic strategies, including the identifying triggering events, the molecular bases of remission and progression, and the T cell epitopes involved.
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Affiliation(s)
- Pierre Ronco
- Rare and Common Kidney Diseases: From Molecular Mechanisms to Personalized Medicine Unit, INSERM UMRS 1155, Sorbonne Université, 75020 Paris, France;
| | - Hanna Debiec
- Rare and Common Kidney Diseases: From Molecular Mechanisms to Personalized Medicine Unit, INSERM UMRS 1155, Sorbonne Université, 75020 Paris, France;
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8
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Membranous Nephropathy and Anti-Podocytes Antibodies: Implications for the Diagnostic Workup and Disease Management. BIOMED RESEARCH INTERNATIONAL 2018; 2018:6281054. [PMID: 29511687 PMCID: PMC5817285 DOI: 10.1155/2018/6281054] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 08/31/2017] [Accepted: 10/15/2017] [Indexed: 12/11/2022]
Abstract
The discovery of circulating antibodies specific for native podocyte antigens has transformed the diagnostic workup and greatly improved management of idiopathic membranous nephropathy (iMN). In addition, their identification has clearly characterized iMN as a largely autoimmune disorder. Anti-PLA2R1 antibodies are detected in approximately 70% to 80% and anti-THSD7A antibodies in only 2% of adult patients with iMN. The presence of anti-THSD7A antibodies is associated with increased risk of malignancy. The assessment of PLA2R1 and THSD7A antigen expression in glomerular immune deposits has a better sensitivity than measurement of the corresponding autoantibodies. Therefore, in the presence of circulating anti-podocytes autoantibodies and/or enhanced expression of PLA2R1 and THSD7A antigens MN should be considered as primary MN (pMN). Anti-PLA2R1 or anti-THSD7A autoantibodies have been proposed as biomarkers of autoimmune disease activity and their blood levels should be regularly monitored in pMN to evaluate disease activity and predict outcomes. We propose a revised clinical workup flow for patients with MN that recommends assessment of kidney biopsy for PLA2R1 and THSD7A antigen expression, screening for circulating anti-podocytes antibodies, and assessment for secondary causes, especially cancer, in patients with THSD7A antibodies. Persistence of anti-podocyte antibodies for 6 months or their increase in association with nephrotic proteinuria should lead to the introduction of immunosuppressive therapies. Recent data have reported the efficacy and safety of new specific therapies targeting B cells (anti-CD20 antibodies, inhibitors of proteasome) in pMN which should lead to an update of currently outdated treatment guidelines.
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9
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Kronbichler A, Oh J, Meijers B, Mayer G, Shin JI. Recent Progress in Deciphering the Etiopathogenesis of Primary Membranous Nephropathy. BIOMED RESEARCH INTERNATIONAL 2017; 2017:1936372. [PMID: 28904948 PMCID: PMC5585565 DOI: 10.1155/2017/1936372] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 07/18/2017] [Indexed: 12/24/2022]
Abstract
Primary membranous nephropathy (MN) is the leading cause of nephrotic syndrome in adults. Discovery of several antibodies has contributed to an increased understanding of MN. Antibodies against the M-type phospholipase A2 receptor (PLA2R) are present in 50-100% with primary MN and are associated with a lower frequency of spontaneous remission. High levels are linked with a higher probability of treatment resistance, higher proteinuria, and impaired renal function, as well as a more rapid decline of kidney function during follow-up. Immunologic remission precedes reduction of proteinuria by months. Pretransplant evaluation of PLA2R antibodies is warranted to predict recurrence of disease following renal transplantation. Several risk alleles related to the PLA2R1 gene and within the HLA loci have been identified, whereas epitope spreading of PLA2R may predict treatment response. More recently, thrombospondin type 1 domain-containing 7A (THSD7A) antibodies have been discovered in primary MN. Several other rare antigens have been described, including antibodies against neutral endopeptidase as a cause of antenatal MN and circulating cationic bovine serum albumin as an antigen with implications in childhood MN. This review focuses on the progress with a special focus on diagnostic accuracy, predictive value, and treatment implications of the established and proposed antigens.
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Affiliation(s)
- Andreas Kronbichler
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria
| | - Jun Oh
- Pediatric Nephrology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Björn Meijers
- Department of Nephrology, UZ Leuven, Leuven, Belgium
- Department of Immunology and Microbiology, KU Leuven, Leuven, Belgium
| | - Gert Mayer
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria
| | - Jae Il Shin
- Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Republic of Korea
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10
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Lessons from a rare disease: IgG subclass and disease severity in alloimmune antenatal membranous nephropathy. Kidney Int 2016; 87:494-7. [PMID: 25723631 DOI: 10.1038/ki.2014.367] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Fetomaternal alloimmunization against neutral endopeptidase (NEP) is a rare cause of antenatal membranous nephropathy, yet lessons from such cases continue to elucidate important pathophysiologic points. Vivarelli and colleagues describe two recent cases of this disease and demonstrate that despite a common genetic cause, differences in maternal anti-NEP IgG subclass modulate disease severity through such mechanisms as complement activation and enzyme inhibition.
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11
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Asmandar S, Figuères ML, Goujon JM, Noël LH, Hummel A. [Diagnostic value of IgG subtypes in membranous nephropathy: A case report]. Nephrol Ther 2015; 11:169-72. [PMID: 25921735 DOI: 10.1016/j.nephro.2015.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 02/01/2015] [Accepted: 02/04/2015] [Indexed: 10/23/2022]
Abstract
The study of immunoglobulin G subtypes constituting immune deposits present in membranous nephropathy is useful to guide diagnosis. IgG4 deposits are more often seen in primitive forms of membranous nephropathy due to autoantibody (anti-phospholipase A2 receptor in a majority of cases). These deposits are polytypic. In secondary forms, deposits are constituted of IgG1, IgG2 and IgG3. We report the case of a 52-year-old woman whose renal biopsy, done for glomerular proteinuria, shows membranous nephropathy with monotypic IgG4 deposits with no overt hematologic malignancy and no anti-PLA2R antibodies.
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Affiliation(s)
- Safaa Asmandar
- Laboratoire d'anatomie pathologique, université René-Descartes, hôpital Necker, 75015 Paris, France
| | - Marie-Lucile Figuères
- Laboratoire d'anatomie pathologique, université René-Descartes, hôpital Necker, 75015 Paris, France
| | - Jean-Michel Goujon
- Laboratoire d'anatomie pathologique, université de Poitiers, 86000 Poitiers, France
| | - Laure-Hélène Noël
- Laboratoire d'anatomie pathologique, université René-Descartes, hôpital Necker, 75015 Paris, France
| | - Aurélie Hummel
- Pôle de néphrologie et de transplantation, université René-Descartes, hôpital Necker, 75015 Paris, France.
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12
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Genetic homogeneity but IgG subclass-dependent clinical variability of alloimmune membranous nephropathy with anti-neutral endopeptidase antibodies. Kidney Int 2015; 87:602-9. [PMID: 25565308 DOI: 10.1038/ki.2014.381] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 09/16/2014] [Accepted: 09/18/2014] [Indexed: 11/09/2022]
Abstract
Alloimmune antenatal membranous nephropathy (MN) during pregnancy results from antibodies produced by a neutral endopeptidase (NEP)-deficient mother. Here we report two recent cases that provide clues to the severity of renal disease. Mothers of the two children had circulating antibodies against NEP showing the characteristic species-dependent pattern by immunofluorescence on kidney slices. A German mother produced predominantly anti-NEP IgG4 accompanied by a low amount of IgG1. Her child recovered renal function within a few weeks. In sharp contrast, an Italian mother mainly produced complement-fixing anti-NEP IgG1, which also inhibits NEP enzymatic activity, whereas anti-NEP IgG4 has a weak inhibitory potency. Her child was dialyzed for several weeks. A kidney biopsy performed at 12 days of age showed MN, ischemic glomeruli, and arteriolar and tubular lesions. A second biopsy performed at 12 weeks of age showed aggravation with an increased number of collapsed capillary tufts. Both mothers were homozygous for the truncating deletion mutation 466delC and were thus NEP deficient. The 466delC mutation, identified in three previously described families, suggests a founder effect. Because of the potential severity of alloimmune antenatal MN, it is essential to identify families at risk by the detection of anti-NEP antibodies and NEP antigen in urine. On the basis of the five families identified to date, we propose an algorithm for the diagnosis of the disease and the prevention of complications.
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13
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Abstract
Microscopic and gross hematuria, while rare in healthy newborns, is more common in premature infants, particularly those cared for in the neonatal intensive care unit. Hematuria may be transient, but may require evaluation, investigation, and intervention in a timely manner. This article discusses the causes, workup, and treatment of the more common forms of newborn hematuria.
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14
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Immunopathogenesis of membranous nephropathy: an update. Semin Immunopathol 2014; 36:381-97. [PMID: 24715030 DOI: 10.1007/s00281-014-0423-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 03/17/2014] [Indexed: 10/25/2022]
Abstract
Membranous nephropathy (MN) is a non-inflammatory organ-specific autoimmune disease which affects the kidney glomerulus, resulting in the formation of immune deposits on the outer aspect of the glomerular basement membrane, complement-mediated proteinuria, and severe renal failure in 30% of patients. In the last 10 years, substantial advances have been made in the understanding of the molecular bases of MN, with the identification of several antigens and predisposing genes in children and adults. These ground-breaking findings already have a major impact on diagnosis and monitoring and to some extent on therapies. However, there is evidence that the disease is more complex and involves a variety of antigen-antibody systems and genes involved in immune response, progression, recovery, and protective mechanisms. We herein review these recent findings which open new perspectives of research. Understanding the complex pathogenesis of MN will offer many opportunities for future therapeutic interventions and will hopefully have a major impact on patient care. New insights into the molecular mechanisms of MN may also enlighten the pathogenesis of organ-specific autoimmune diseases.
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15
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Olaru F, Luo W, Suleiman H, St John PL, Ge L, Mezo AR, Shaw AS, Abrahamson DR, Miner JH, Borza DB. Neonatal Fc receptor promotes immune complex-mediated glomerular disease. J Am Soc Nephrol 2013; 25:918-25. [PMID: 24357670 DOI: 10.1681/asn.2013050498] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The neonatal Fc receptor (FcRn) is a major regulator of IgG and albumin homeostasis systemically and in the kidneys. We investigated the role of FcRn in the development of immune complex-mediated glomerular disease in mice. C57Bl/6 mice immunized with the noncollagenous domain of the α3 chain of type IV collagen (α3NC1) developed albuminuria associated with granular capillary loop deposition of exogenous antigen, mouse IgG, C3 and C5b-9, and podocyte injury. High-resolution imaging showed abundant IgG deposition in the expanded glomerular basement membrane, especially in regions corresponding to subepithelial electron dense deposits. FcRn-null and -humanized mice immunized with α3NC1 developed no albuminuria and had lower levels of serum IgG anti-α3NC1 antibodies and reduced glomerular deposition of IgG, antigen, and complement. Our results show that FcRn promotes the formation of subepithelial immune complexes and subsequent glomerular pathology leading to proteinuria, potentially by maintaining higher serum levels of pathogenic IgG antibodies. Therefore, reducing pathogenic IgG levels by pharmacologic inhibition of FcRn may provide a novel approach for the treatment of immune complex-mediated glomerular diseases. As proof of concept, we showed that a peptide inhibiting the interaction between human FcRn and human IgG accelerated the degradation of human IgG anti-α3NC1 autoantibodies injected into FCRN-humanized mice as effectively as genetic ablation of FcRn, thus preventing the glomerular deposition of immune complexes containing human IgG.
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Affiliation(s)
- Florina Olaru
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Wentian Luo
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | - Patricia L St John
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas
| | - Linna Ge
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Adam R Mezo
- Biogen Idec Hemophilia, Waltham, Massachusetts; and
| | | | - Dale R Abrahamson
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas
| | - Jeffrey H Miner
- Renal Division, Washington University School of Medicine, St. Louis, Missouri
| | - Dorin-Bogdan Borza
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee; Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee
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16
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Devriendt A, Cassart M, Massez A, Donner C, Avni FE. Fetal kidneys: additional sonographic criteria of normal development. Prenat Diagn 2013; 33:1248-52. [DOI: 10.1002/pd.4240] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 09/07/2013] [Accepted: 09/12/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Arnaud Devriendt
- Department of Medical Imaging; Erasme Hospital; Brussels Belgium
| | - Marie Cassart
- Department of Medical Imaging; Ixelles Hospital; Ixelles Belgium
| | - Anne Massez
- Department of Medical Imaging; Erasme Hospital; Brussels Belgium
| | - Catherine Donner
- Department of Gynecology and Obstetrics; Erasme Hospital; Brussels Belgium
| | - Fred E. Avni
- Department of Pediatric Imaging; Jeanne de Flandre Hospital, CHRU - Lille; Lille France
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17
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Ronco P, Debiec H. [Pathophysiology of extramembranous glomerulopathies. Fifty years of progress, from laboratory to patient]. Biol Aujourdhui 2013; 207:249-59. [PMID: 24594573 DOI: 10.1051/jbio/2013025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Indexed: 11/15/2022]
Abstract
Membranous nephropathy (MN) is a kidney disease characterized by deposition of immune complexes and complement on the outer aspect of the glomerular capillary wall. It is responsible for a loss of serum proteins in the urine and kidney failure. During the last ten years, considerable progress has occurred in the understanding of the molecular bases of the disease with the description of three distinct mechanisms in humans. In the neonatal allo-immune form, antibodies are directed against neutral endopeptidase (NEP), a podocyte antigen absent in the mothers who become immunized against this antigen expressed by placenta cells during pregnancy. NEP was the first podocyte antigen to be identified in MN. Most adult forms of MN are autoimmune diseases without identified etiology (primary MN), linked to the production of antibodies raised against another podocyte antigen, the type-M phospholipase A2 receptor (PLA2R1). Anti-PLA2R1 antibodies are detected in 70 to 80% of patients before any immunosuppressive treatment, and only occasionally in secondary forms of MN, variants of PLAR1 and HLA-DQA1 genes are very significantly associated with occurrence of primary MN in Caucasians. The third mechanism is characterized by immunization against a foreign protein, cationic bovine serum albumin (BSA), which is involved in rare forms of MN during early childhood. This finding points to a possible role of food and environmental antigens in membranous nephropathy.
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Glomérulopathie extramembraneuse par immunisation immunisationmaterno-fœtale. BULLETIN DE L'ACADÉMIE NATIONALE DE MÉDECINE 2012. [DOI: 10.1016/s0001-4079(19)31687-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Ronco P, Debiec H. Pathogenesis of membranous nephropathy: recent advances and future challenges. Nat Rev Nephrol 2012; 8:203-13. [DOI: 10.1038/nrneph.2012.35] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Abstract
Antibodies to neutral endopeptidase, a podocyte protein, are responsible for rare alloimmune neonatal membranous nephropathy that develops in children from neutral endopeptidase-deficient mothers. Neutral endopeptidase was the first podocyte antigen described in human membranous nephropathy. PLA2R1, the type-M receptor of soluble phospholipase A2, is a major target antigen in so-called idiopathic membranous nephropathy in adults. Antibodies to PLA2R1 are detected in 60 to 80% of patients before immunosuppressive treatment, and are only occasionally found in secondary membranous nephropathy. To date, they have not been detected in other pathological conditions and in healthy individuals. PLA2R1 and HLA-DQA1 gene variants defined by single nucleotide polymorphisms are strongly associated with idiopathic membranous nephropathy in patients of white ancestry, and can thus be considered as predisposing genes. In addition to their diagnostic value, anti-PLA2R1 antibodies can be used to monitor treatment. Immunization against cationic bovine serum albumin is a cause of early childhood membranous nephropathy. This finding points to a possible role of food and environmental antigens in membranous nephropathy. The newly identified antigen-antibody systems should be considered as molecular signatures challenging the uniform histological definition and having a major impact on patient care in a near future.
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Smyk D, Grammatikopoulos T, Daponte A, Rigopoulou EI, Bogdanos DP. Fetomaternal alloimmunity as a cause of liver disease. AUTOIMMUNITY HIGHLIGHTS 2011; 2:21-8. [PMID: 26000116 PMCID: PMC4389071 DOI: 10.1007/s13317-011-0019-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 02/14/2011] [Indexed: 12/29/2022]
Abstract
Fetomaternal alloimmune disease has traditionally been associated with haematological disease such as fetomaternal alloimmune thrombocytopaenia and Rh haemolytic anaemia, but is now known to also be organ specific. Alloimmune membranous glomerulonephritis (AMG) is one of the most well understood organ-specific alloimmune diseases. Neonatal haemochromatosis (NH) is a rare condition characterised by early liver failure in infants, with evidence suggesting that it is also alloimmune. Both AMG and NH appear to involve the passive transfer of alloantibodies to the fetus, which bind a specific alloantigen, fix complement and activate the terminal complement cascade. Although differences between AMG and NH are known, and evidence of the presence of antigen-specific alloantibodies in NH is still missing, we will use AMG as an example of fetomaternal organ specific alloimmune disease, and critically compare this to other emerging evidence that indicates that NH is also alloimmune.
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Affiliation(s)
- Daniel Smyk
- Liver Immunopathology and Immunodiagnostics, Institute of Liver Studies and Liver Unit, King's College London School of Medicine at King's College Hospital, Denmark Hill Campus, London, SE5 9RS UK
| | - Tassos Grammatikopoulos
- Paediatric Liver, GI and Nutrition Centre, King's College London School of Medicine at King's College Hospital, London, SE5 9RS UK
| | - Alexandros Daponte
- Department of Obstetrics and Gynaecology, University of Thessaly Medical School, 41222 Larissa, Thessaly Greece
| | - Eirini I Rigopoulou
- Department of Medicine and Research Laboratory of Internal Medicine, University of Thessaly Medical School, 41222 Larissa, Thessaly Greece
| | - Dimitrios P Bogdanos
- Liver Immunopathology and Immunodiagnostics, Institute of Liver Studies and Liver Unit, King's College London School of Medicine at King's College Hospital, Denmark Hill Campus, London, SE5 9RS UK
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Avni EF, Vandenhoute K, Devriendt A, Ismaili K, Hackx M, Janssen F, Hall M. Update on congenital nephrotic syndromes and the contribution of US. Pediatr Radiol 2011; 41:76-81. [PMID: 20714714 DOI: 10.1007/s00247-010-1793-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 06/05/2010] [Accepted: 06/21/2010] [Indexed: 11/26/2022]
Abstract
The clinical classification of nephrotic syndrome (NS) is based on age at presentation. However, this classification is arbitrary because the majority of early onset NS has a genetic origin and has a widespread age of onset (from fetal life to several years). The aims of this review are to illustrate the knowledge accumulated on congenital nephrotic syndrome (CNS) in terms of genetics, classification, findings at histology and US-based on a review of the literature.
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Affiliation(s)
- E Fred Avni
- Department of Medical Imaging, University Clinics of Brussels, Erasme Hospital, Brussels, Belgium.
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Avni FE, Hall M. Renal cystic diseases in children: new concepts. Pediatr Radiol 2010; 40:939-46. [PMID: 20432012 DOI: 10.1007/s00247-010-1599-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 01/31/2010] [Indexed: 12/19/2022]
Abstract
This review highlights the changes that have occurred in the general approach to cystic renal diseases in children. For instance, genetic mutations at the level of the primary cilia are considered as the origin of many renal cystic diseases. Furthermore, these diseases are now included in the spectrum of the hepato-renal fibrocystic diseases. Imaging plays an important role as it helps to detect and characterize many of the cystic diseases based on a detailed sonographic analysis. The diagnosis can be achieved during fetal life or after birth. Hyperechoic kidneys and/or renal cysts are the main sonographic signs leading to such diagnosis. US is able to differentiate between recessive and dominant polycystic kidney diseases, hepatocyte nuclear factor 1 Beta mutation, glomerulocystic kidneys and nephronophtisis. MR imaging can, in selected cases, provide additional information including the progressive associated hepatic changes.
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Affiliation(s)
- Fred E Avni
- Departments of Medical Imaging and Pediatric Nephrology, University Clinics of Brussels-Erasme Hospital, 808 Route de Lennik, 1070 Brussels, Belgium.
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Ronco P, Debiec H. Antigen Identification in Membranous Nephropathy Moves toward Targeted Monitoring and New Therapy: Figure 1. J Am Soc Nephrol 2010; 21:564-9. [DOI: 10.1681/asn.2009121220] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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Abstract
Fetomaternal alloimmunization with antenatal glomerulopathies (FMAIG) is a recently described alloimmune disorder, which results from the production of maternal antibodies that cross the placenta, bind to fetal glomerular podocytes, and mediate renal disease. The pathogenic antibodies are directed against CD10/neutral endopeptidase (NEP). The infant's mother is NEP-deficient and thus she becomes immunized during the first pregnancy against CD10/NEP expressed by placental cells. Because future pregnancies in CD10/NEP-immunized mothers are at high risk for the fetus, detection of anti-NEP antibodies in pregnant mothers and antigen-driven therapies including induction of tolerance, are urgently needed. This ideally requires identification of the pathogenic epitopes born by the antigen and specifically recognized by B- and T-cells. We have recently characterized such epitopes that will be used in diagnostic tests (ELISA) and for new therapeutic approaches based on peptide-specific immune intervention. For this purpose, we have developed an experimental model by crossing NEP/CD10-deficient female mice to wild-type males. The females develop an alloimmune reaction against NEP, which is a prerequisite for tolerance induction experiments. Although NEP/CD10 does not seem to be involved in common idiopathic forms of membranous nephropathy in the adult, alloimmune antibodies may be implicated in de novo membranous nephropathy that develop in the kidney graft and after alloimmune bone marrow transplantation.
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Affiliation(s)
- Pierre Ronco
- Unité Inserm UMR S 702, UPMC Université Paris 6, Assistance Publique-Hôpitaux de Paris, Hôpital Tenon, Paris, France.
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Abstract
Fetomaternal alloimmunization with antenatal glomerulopathies (FMAIG) is a recently described alloimmune disorder, which results from maternal antibodies that cross the placenta, bind to fetal glomerular podocytes, and mediate renal disease. The pathogenic antibodies are directed against neutral endopeptidase (NEP). The infant's mother is NEP-deficient and thus she becomes immunized during pregnancy against NEP expressed by placental cells. Because future pregnancies in NEP-immunized mothers are at high risk for the fetus, detection of anti-NEP antibodies in pregnant mothers and antigen-driven therapies including induction of mucosal tolerance, are urgently needed. This ideally requires identification of the pathogenic epitopes born by the antigen. We have recently characterized two linear B cell epitopes on the NEP that are specifically recognized by the mother's antibodies. The identification of these B cell epitopes is useful for diagnostic tests and may lead to future development of new therapeutic approaches based on peptide-specific immune intervention.
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Affiliation(s)
- Hanna Debiec
- INSERM U 702, Pierre et Marie Curie University-Paris, UMRS, Ap-Hp Tenon Hospital, Paris, France.
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Ronco P, Debiec H. Target antigens and nephritogenic antibodies in membranous nephropathy: of rats and men. Semin Immunopathol 2007; 29:445-58. [PMID: 17899086 DOI: 10.1007/s00281-007-0091-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 08/17/2007] [Indexed: 01/31/2023]
Abstract
Membranous nephropathy, a disease characterized by an accumulation of immune deposits on the outer aspect of the glomerular basement membrane, is the most common cause of idiopathic nephrotic syndrome in white adults. In the rat model of Heymann nephritis, the target antigen of antibodies is megalin, a multiligand receptor expressed at the podocyte cell surface. This review summarizes key findings provided by this experimental model and by our discovery of neutral endopeptidase being the alloantigen involved in neonatal cases of membranous nephropathy. We discuss the role of alloimmunization as a new mechanism of renal disease and the approach that we use to identify new podocyte antigens. We also summarize current knowledge on the mechanism of proteinuria, with special emphasis on the role of complement. In conclusion, substantial progresses have been made in understanding molecular mechanisms of membranous nephropathy, which should lead to novel therapeutic approaches.
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Affiliation(s)
- P Ronco
- INSERM Unit 702, Hôpital Tenon, 4 rue de la Chine, 75020, Paris, France.
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Abstract
BACKGROUND Membranous nephropathy (MN), a major cause of nephrotic syndrome in the adult, is an immune-mediated disease characterized by the accumulation of subepithelial immune deposits leading to complement activation and podocyte injury. However, the target antigens of circulating antibodies are unknown. Current treatments for patients with MN are entirely empirical, and concept-driven therapies are dramatically lacking. METHODS Specificity of circulating antibodies and composition of glomerular deposits were analyzed in Heymann nephritis (HN), a faithful rat model of MN, and in a subset of patients with antenatal MN. RESULTS 20 years after the identification of megalin as the podocyte target antigen of nephritogenic antibodies in HN, we identified the human counterpart of megalin, the enzymatic podocyte antigen neutral endopeptidase (NEP). Antibodies to megalin or NEP induce formation of subepithelial immune deposits and of C5b-9, the membrane attack complex of complement. CONCLUSION It is likely that antigens involved in idiopathic MN are expressed at the podocyte membrane. Their identification together with that of immunodominant epitopes may lead to specific antigen/ epitope-based immunotherapy aimed at inducing specific tolerance.
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Affiliation(s)
- Pierre Ronco
- INSERM Unit UMR S 702, Pierre et Marie Curie University-Paris 6, AP-HP (Tenon Hospital), Paris, France.
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Ronco P, Debiec H. Molecular dissection of target antigens and nephritogenic antibodies in membranous nephropathy: towards epitope-driven therapies. J Am Soc Nephrol 2006; 17:1772-4. [PMID: 16775025 DOI: 10.1681/asn.2006050497] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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