1
|
Stea ED, D'Ettorre G, Mitrotti A, Gesualdo L. The complement system in the pathogenesis and progression of kidney diseases: What doesn't kill you makes you older. Eur J Intern Med 2024; 124:22-31. [PMID: 38461065 DOI: 10.1016/j.ejim.2024.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 01/31/2024] [Accepted: 02/09/2024] [Indexed: 03/11/2024]
Abstract
The Complement System is an evolutionarily conserved component of immunity that plays a key role in host defense against infections and tissue homeostasis. However, the dysfunction of the Complement System can result in tissue damage and inflammation, thereby contributing to the development and progression of various renal diseases, ranging from atypical Hemolytic Uremic Syndrome to glomerulonephritis. Therapeutic interventions targeting the complement system have demonstrated promising results in both preclinical and clinical studies. Currently, several complement inhibitors are being developed for the treatment of complement-mediated renal diseases. This review aims to summarize the most recent insights into complement activation and therapeutic inhibition in renal diseases. Furthermore, it offers potential directions for the future rational use of complement inhibitor drugs in the context of renal diseases.
Collapse
Affiliation(s)
- Emma Diletta Stea
- Department of Precision and Regenerative Medicine and Ionian Area (DiMePre-J), Nephrology and Urology Units, University of Bari Aldo Moro, Bari, Italy
| | | | - Adele Mitrotti
- Department of Precision and Regenerative Medicine and Ionian Area (DiMePre-J), Nephrology and Urology Units, University of Bari Aldo Moro, Bari, Italy
| | - Loreto Gesualdo
- Department of Precision and Regenerative Medicine and Ionian Area (DiMePre-J), Nephrology and Urology Units, University of Bari Aldo Moro, Bari, Italy.
| |
Collapse
|
2
|
Uzzo M, Kronbichler A, Alberici F, Bajema I. Nonlupus Full House Nephropathy: A Systematic Review. Clin J Am Soc Nephrol 2024; 19:743-754. [PMID: 38527995 PMCID: PMC11168831 DOI: 10.2215/cjn.0000000000000438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 03/19/2024] [Indexed: 03/27/2024]
Abstract
Key Points Nonlupus full house nephropathy is a rare, complex entity: confusion arises by the low-quality evidence and the lack of consensus on nomenclature. This systematic review supports that systemic lupus erythematosus and nonlupus full house nephropathy are distinct clinical entities, with comparable outcomes. The identification of three pathogenetic categories provides further clues for a shared clinical and diagnostic approach to the disease. Background The presence of a full house pattern at immunofluorescence on kidney biopsy in a patient without clinical and laboratory features of systemic lupus erythematosus (SLE) has led to the descriptive term nonlupus full house nephropathy. This systematic review and meta-analysis focus on nonlupus full house nephropathy nomenclature, clinical findings, and outcomes. Methods In a reiterative process, all identified terms for nonlupus full house nephropathy and other medical subject headings terms were searched in PubMed. Out of 344 results, 57 records published between 1982 and 2022 were included in the analysis. Clinical data of single patients from different reports were collected. Patients were classified into three pathogenetic categories, which were compared according to baseline characteristics, treatments, and outcomes. Results Out of the 57 records, 61% were case reports. Nonlupus full house nephropathy was addressed with 17 different names. We identified 148 patients: 75 (51%) were men; median age 35 (23–58) years. Serum creatinine and proteinuria at onset were 1.4 (0.8–2.5) mg/dl and 5.7 (2.7–8.8) g/d. About half of patients achieved complete response. A causative agent was identified in 51 patients (44%), mainly infectious (41%). Secondary nonlupus full house nephropathy was mostly nonrelapsing with worse kidney function at onset compared with idiopathic disease (P = 0.001). Among the 57 patients (50%) with idiopathic nonlupus full house nephropathy, complete response was comparable between patients treated with immunosuppression and supportive therapy; however, proteinuria and creatinine at onset were higher in patients treated with immunosuppression (P = 0.09 and P = 0.07). The remaining 7 patients (6%) developed SLE after a median follow-up of 5.0 (1.9–9.0) years. Conclusions Our data support that SLE and nonlupus full house nephropathy are distinct clinical entities, with comparable outcomes. A small subset of patients develops SLE during follow-up. Nonlupus full house nephropathy is addressed by many different names in the literature. The identification of three pathogenetic categories provides further clues for the management of the disease.
Collapse
Affiliation(s)
- Martina Uzzo
- Department of Medicine and Surgery, University of Milano-Bicocca and ASST Monza, Monza, Italy
- Department of Pathology and Medical Biology, University Medical Center, University of Groningen, Groningen, The Netherlands
| | - Andreas Kronbichler
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, Innsbruck, Austria
| | - Federico Alberici
- Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Ingeborg Bajema
- Department of Pathology and Medical Biology, University Medical Center, University of Groningen, Groningen, The Netherlands
| |
Collapse
|
3
|
L’Imperio V, Ceola S, Cerbelli B, Barreca A, Pagni F. Systemic vasculitis involving the kidney: the nephropathologist's point of view. Pathologica 2024; 116:104-118. [PMID: 38767543 PMCID: PMC11138762 DOI: 10.32074/1591-951x-990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 03/01/2024] [Indexed: 05/22/2024] Open
Abstract
Kidneys are often targets of systemic vasculitis (SVs), being affected in many different forms and representing a possible sentinel of an underlying multi-organ condition. Renal biopsy still remains the gold standard for the identification, characterization and classification of these diseases, solving complex differential diagnosis thanks to the combined application of light microscopy (LM), immunofluorescence (IF) and electron microscopy (EM). Due to the progressively increasing complexity of renal vasculitis classification systems (e.g. pauci-immune vs immune complex related forms), a clinico-pathological approach is mandatory and adequate technical and interpretative expertise in nephropathology is required to ensure the best standard of care for our patients. In this complex background, the present review aims at summarising the current knowledge and challenges in the world of renal vasculitis, unveiling the potential role of the introduction of digital pathology in this setting, from the creation of hub-spoke networks to the future application of artificial intelligence (AI) tools to aid in the diagnostic and scoring/classification process.
Collapse
Affiliation(s)
- Vincenzo L’Imperio
- Department of Medicine and Surgery, Pathology, IRCCS Fondazione San Gerardo dei Tintori, University of Milano-Bicocca, Italy
| | - Stefano Ceola
- Department of Medicine and Surgery, Pathology, IRCCS Fondazione San Gerardo dei Tintori, University of Milano-Bicocca, Italy
| | - Bruna Cerbelli
- Department of Medical Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy
| | - Antonella Barreca
- Pathology Unit, Città della Salute e della Scienza di Torino University Hospital, Turin, Italy
| | - Fabio Pagni
- Department of Medicine and Surgery, Pathology, IRCCS Fondazione San Gerardo dei Tintori, University of Milano-Bicocca, Italy
| |
Collapse
|
4
|
Noris M, Remuzzi G. C3G and Ig-MPGN-treatment standard. Nephrol Dial Transplant 2024; 39:202-214. [PMID: 37604793 PMCID: PMC10828209 DOI: 10.1093/ndt/gfad182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Indexed: 08/23/2023] Open
Abstract
Among the broad spectrum of membranoproliferative glomerulonephritis (MPGN), immunofluorescence distinguishes C3 glomerulopathy (C3G), with predominant C3 deposits, and immunoglobulin-associated MPGN (Ig-MPGN), with combined C3 and Ig. However, there are several intersections between C3G and Ig-MPGN. Primary C3G and Ig-MPGN share the same prevalence of low serum C3 levels and of abnormalities of the alternative pathway of complement, and patients who present a bioptic pattern of Ig-MPGN at onset may show a C3G pattern in a subsequent biopsy. There is no specific therapy for primary C3G and Ig-MPGN and prognosis is unfavourable. The only recommended indications are inhibitors of the renin-angiotensin system, lipid-lowering agents and other renoprotective agents. The other drugs used currently, such as corticosteroids and mycophenolate mofetil, are often ineffective. The anti-C5 monoclonal antibody eculizumab has been tested in several patients, with mixed results. One reason for the uncertainty is the extremely variable clinical course, most likely reflecting a heterogeneous pathogenesis. An unsupervised clustering analysis that included histologic, biochemical, genetic and clinical data available at onset in patients with primary C3G and Ig-MPGN identified four clusters characterized by specific pathogenic mechanisms. This approach may facilitate accurate diagnosis and development of targeted therapies. Several trials are ongoing with drugs targeting different molecules of the complement cascade, however it is important to consider which component of the cascade may be the most appropriate for each patient. We review the current standards of treatment and discuss novel developments in the pathophysiology, diagnosis, outcome prediction and management of C3G and Ig-MPGN.
Collapse
Affiliation(s)
- Marina Noris
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases Aldo e Cele Daccò Ranica, Bergamo, Italy
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases Aldo e Cele Daccò Ranica, Bergamo, Italy
| |
Collapse
|
5
|
Vivarelli M, Bomback AS, Meier M, Wang Y, Webb NJ, Veldandi UK, Smith RJ, Kavanagh D. Iptacopan in Idiopathic Immune Complex-Mediated Membranoproliferative Glomerulonephritis: Protocol of the APPARENT Multicenter, Randomized Phase 3 Study. Kidney Int Rep 2024; 9:64-72. [PMID: 38312795 PMCID: PMC10831369 DOI: 10.1016/j.ekir.2023.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/16/2023] [Accepted: 10/23/2023] [Indexed: 02/06/2024] Open
Abstract
Introduction Immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) is an ultra-rare, fast-progressing kidney disease that may be idiopathic (primary) or secondary to chronic infection, autoimmune disorders, or monoclonal gammopathies. Dysregulation of the alternative complement pathway is implicated in the pathophysiology of IC-MPGN; and currently, there are no approved targeted treatments. Iptacopan is an oral, highly potent proximal complement inhibitor that specifically binds to factor B and inhibits the alternative pathway (AP). Methods This randomized, double-blind, placebo-controlled phase 3 study (APPARENT; NCT05755386) will evaluate the efficacy and safety of iptacopan in patients with idiopathic (primary) IC-MPGN, enrolling up to 68 patients (minimum of 10 adolescents) aged 12 to 60 years with biopsy-confirmed IC-MPGN, proteinuria ≥1 g/g, and estimated glomerular filtration rate (eGFR) ≥30 ml/min per 1.73 m2. All patients will receive maximally tolerated angiotensin-converting enzyme inhibitor/angiotensin receptor blocker and vaccination against encapsulated bacteria. Patients with any organ transplant, progressive crescentic glomerulonephritis, or kidney biopsy with >50% interstitial fibrosis/tubular atrophy, will be excluded. Patients will be randomized 1:1 to receive either iptacopan 200 mg twice daily (bid) or placebo for 6 months, followed by open-label treatment with iptacopan 200 mg bid for all patients for 6 months. The primary objective of the study is to evaluate the efficacy of iptacopan versus placebo in proteinuria reduction measured as urine protein-to-creatinine ratio (UPCR) (24-h urine) at 6 months. Key secondary end points will assess kidney function measured by eGFR, patients who achieve a proteinuria-eGFR composite end point, and patient-reported fatigue. Conclusion This study will provide evidence toward the efficacy and safety of iptacopan in idiopathic (primary) IC-MPGN.
Collapse
Affiliation(s)
- Marina Vivarelli
- Division of Nephrology, Laboratory of Nephrology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Andrew S. Bomback
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Matthias Meier
- Global Drug Development, Novartis Pharma AG, Basel, Switzerland
| | - Yaqin Wang
- Global Drug Development, Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| | | | | | - Richard J.H. Smith
- Molecular Otolaryngology and Renal Research Laboratories and the Departments of Internal Medicine and Pediatrics (Divisions of Nephrology), Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - David Kavanagh
- National Renal Complement Therapeutics Centre, Newcastle upon Tyne Hospitals, National Health Service Foundation Trust, Newcastle upon Tyne, UK
| |
Collapse
|
6
|
Rydberg V, Aradottir SS, Kristoffersson AC, Svitacheva N, Karpman D. Genetic investigation of Nordic patients with complement-mediated kidney diseases. Front Immunol 2023; 14:1254759. [PMID: 37744338 PMCID: PMC10513385 DOI: 10.3389/fimmu.2023.1254759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 08/21/2023] [Indexed: 09/26/2023] Open
Abstract
Background Complement activation in atypical hemolytic uremic syndrome (aHUS), C3 glomerulonephropathy (C3G) and immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) may be associated with rare genetic variants. Here we describe gene variants in the Swedish and Norwegian populations. Methods Patients with these diagnoses (N=141) were referred for genetic screening. Sanger or next-generation sequencing were performed to identify genetic variants in 16 genes associated with these conditions. Nonsynonymous genetic variants are described when they have a minor allele frequency of <1% or were previously reported as being disease-associated. Results In patients with aHUS (n=94, one also had IC-MPGN) 68 different genetic variants or deletions were identified in 60 patients, of which 18 were novel. Thirty-two patients had more than one genetic variant. In patients with C3G (n=40) 29 genetic variants, deletions or duplications were identified in 15 patients, of which 9 were novel. Eight patients had more than one variant. In patients with IC-MPGN (n=7) five genetic variants were identified in five patients. Factor H variants were the most frequent in aHUS and C3 variants in C3G. Seventeen variants occurred in more than one condition. Conclusion Genetic screening of patients with aHUS, C3G and IC-MPGN is of paramount importance for diagnostics and treatment. In this study, we describe genetic assessment of Nordic patients in which 26 novel variants were found.
Collapse
Affiliation(s)
| | | | | | | | - Diana Karpman
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| |
Collapse
|
7
|
Niepolski L, Czekała A, Seget-Dubaniewicz M, Frydrychowicz M, Talarska-Markiewicz P, Kowalska A, Szmelter J, Salwa-Żurawska W, Sirek T, Sobański D, Grabarek BO, Żurawski J. Diagnostic Problems in C3 Glomerulopathy. Biomedicines 2023; 11:biomedicines11041101. [PMID: 37189718 DOI: 10.3390/biomedicines11041101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/14/2023] [Accepted: 03/23/2023] [Indexed: 04/08/2023] Open
Abstract
Background: C3 glomerulopathies (C3GN) are a group of rare kidney diseases associated with impaired complement regulation. The effects of this disease include the accumulation of complement C3 in the kidneys. Based on the clinical data, as well as light, fluorescence, and electron microscopy results, the diagnoses were verified. The study group consisted of biopsy specimens, which were obtained from 332 patients who were diagnosed with C3 glomerulopathy. In all cases, histopathological examinations were performed; deposits of complement C3 and C1q components, as well as the immunoglobulins IgA, IgG, and IgM, were identified using immunofluorescence. Furthermore, electron microscopy was also performed. Results: The histopathological examination results presented cases of C3GN (n = 111) and dense deposit disease (DDD; n = 17). The non-classified (NC) group was the most numerous (n = 204). The lack of classification was due to the poor severity of the lesions, even on the electron microscopic examination or in the presence of intense sclerotic lesions. Conclusions: In cases of suspected C3 glomerulopathies, we believe an electron microscopy examination is necessary. This examination is beneficial in mild-to-extremely-severe cases of this glomerulopathy, where the lesions are barely discernible when using immunofluorescence microscopy.
Collapse
Affiliation(s)
- Leszek Niepolski
- Department of Physiology, Poznan University of Medical Sciences, 60-567 Poznan, Poland
| | - Anna Czekała
- Department of Clinical Pathology, Poznan University of Medical Sciences, 60-567 Poznan, Poland
| | | | | | | | - Angelika Kowalska
- Department of Immunobiology, Poznan University of Medical Sciences, 60-567 Poznan, Poland
| | - Jagoda Szmelter
- Department of Immunobiology, Poznan University of Medical Sciences, 60-567 Poznan, Poland
| | - Wiesława Salwa-Żurawska
- Department of Clinical Pathology, Poznan University of Medical Sciences, 60-567 Poznan, Poland
| | - Tomasz Sirek
- Department of Plastic Surgery, Faculty of Medicine, Academy of Silesia, 40-055 Katowice, Poland
- Department of Histology, Cytophysiology and Embryology, Faculty of Medicine, Academy of Silesia, 40-055 Katowice, Poland
| | - Dawid Sobański
- Department of Histology, Cytophysiology and Embryology, Faculty of Medicine, Academy of Silesia, 40-055 Katowice, Poland
- Department of Neurosurgery, Szpital sw. Rafala w Krakowie, 30-091 Krakow, Poland
| | - Beniamin Oskar Grabarek
- Department of Histology, Cytophysiology and Embryology, Faculty of Medicine, Academy of Silesia, 40-055 Katowice, Poland
- Department of Neurosurgery, Szpital sw. Rafala w Krakowie, 30-091 Krakow, Poland
| | - Jakub Żurawski
- Department of Immunobiology, Poznan University of Medical Sciences, 60-567 Poznan, Poland
| |
Collapse
|
8
|
Diagnostic and Prognostic Comparison of Immune-Complex-Mediated Membranoproliferative Glomerulonephritis and C3 Glomerulopathy. Cells 2023; 12:cells12050712. [PMID: 36899849 PMCID: PMC10000503 DOI: 10.3390/cells12050712] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/19/2023] [Accepted: 02/21/2023] [Indexed: 02/27/2023] Open
Abstract
Membranoproliferative glomerulonephritis (MPGN) is subdivided into immune-complex-mediated glomerulonephritis (IC-MPGN) and C3 glomerulopathy (C3G). Classically, MPGN has a membranoproliferative-type pattern, but other morphologies have also been described depending on the time course and phase of the disease. Our aim was to explore whether the two diseases are truly different, or merely represent the same disease process. All 60 eligible adult MPGN patients diagnosed between 2006 and 2017 in the Helsinki University Hospital district, Finland, were reviewed retrospectively and asked for a follow-up outpatient visit for extensive laboratory analyses. Thirty-seven (62%) had IC-MPGN and 23 (38%) C3G (including one patient with dense deposit disease, DDD). EGFR was below normal (≤60 mL/min/1.73 m2) in 67% of the entire study population, 58% had nephrotic range proteinuria, and a significant proportion had paraproteins in their serum or urine. A classical MPGN-type pattern was seen in only 34% of the whole study population and histological features were similarly distributed. Treatments at baseline or during follow-up did not differ between the groups, nor were there significant differences observed in complement activity or component levels at the follow-up visit. The risk of end-stage kidney disease and survival probability were similar in the groups. IC-MPGN and C3G have surprisingly similar characteristics, kidney and overall survival, which suggests that the current subdivision of MPGN does not add substantial clinical value to the assessment of renal prognosis. The high proportion of paraproteins in patient sera or in urine suggests their involvement in disease development.
Collapse
|
9
|
Michels MAHM, Volokhina EB, van de Kar NCAJ, van den Heuvel LPJ. Challenges in diagnostic testing of nephritic factors. Front Immunol 2022; 13:1036136. [PMID: 36451820 PMCID: PMC9702996 DOI: 10.3389/fimmu.2022.1036136] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 10/12/2022] [Indexed: 09/27/2023] Open
Abstract
Nephritic factors (NeFs) are autoantibodies promoting the activity of the central enzymes of the complement cascade, an important first line of defense of our innate immune system. NeFs stabilize the complement convertase complexes and prevent their natural and regulator-mediated decay. They are mostly associated with rare complement-mediated kidney disorders, in particular with C3 glomerulopathy and related diseases. Although these autoantibodies were already described more than 50 years ago, measuring NeFs for diagnostic purposes remains difficult, and this also complicates our understanding of their clinical associations. In this review, we address the multifactorial challenges of NeF diagnostics. We describe the diseases NeFs are associated with, the heterogenic mechanisms of action of different NeF types, the different methods available in laboratories used for their detection, and efforts for standardization. Finally, we discuss the importance of proper NeF diagnostics for understanding the clinical impact of these autoantibodies in disease pathophysiology and for considering future complement-directed therapy.
Collapse
Affiliation(s)
- Marloes A. H. M. Michels
- Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, Netherlands
| | - Elena B. Volokhina
- Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, Netherlands
- Innatoss Laboratories, Oss, Netherlands
| | - Nicole C. A. J. van de Kar
- Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, Netherlands
| | - Lambertus P.W. J. van den Heuvel
- Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Pediatrics/Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
- Department of Development and Regeneration, University Hospitals Leuven, Leuven, Belgium
| |
Collapse
|
10
|
Heiderscheit AK, Hauer JJ, Smith RJH. C3 glomerulopathy: Understanding an ultra-rare complement-mediated renal disease. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:344-357. [PMID: 35734939 PMCID: PMC9613507 DOI: 10.1002/ajmg.c.31986] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/27/2022] [Accepted: 06/10/2022] [Indexed: 01/29/2023]
Abstract
C3 glomerulopathy (C3G) describes a pathologic pattern of injury diagnosed by renal biopsy. It is characterized by the dominant deposition of the third component of complement (C3) in the renal glomerulus as resolved by immunofluorescence microscopy. The underlying pathophysiology is driven by dysregulation of the alternative pathway of complement in the fluid-phase and in the glomerular microenvironment. Characterization of clinical features and a targeted evaluation for indices and drivers of complement dysregulation are necessary for optimal patient care. Autoantibodies to the C3 and C5 convertases of complement are the most commonly detected drivers of complement dysregulation, although genetic mutations in complement genes can also be found. Approximately half of patients progress to end-stage renal disease within 10 years of diagnosis, and, while transplantation is a viable option, there is high risk for disease recurrence and allograft failure. This poor outcome reflects the lack of disease-specific therapy for C3G, relegating patients to symptomatic treatment to minimize proteinuria and suppress renal inflammation. Fortunately, the future is bright as several anti-complement drugs are currently in clinical trials.
Collapse
Affiliation(s)
- Amanda K. Heiderscheit
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of MedicineUniversity of IowaIowa CityIowaUSA,Graduate PhD Program in Immunology, Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Jill J. Hauer
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Richard J. H. Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of MedicineUniversity of IowaIowa CityIowaUSA,Graduate PhD Program in Immunology, Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| |
Collapse
|
11
|
Riedl Khursigara M, Matsuda-Abedini M, Radhakrishnan S, Hladunewich MA, Lemaire M, Teoh CW, Noone D, Licht C. A Guide for Adult Nephrologists and Hematologists to Managing Atypical Hemolytic Uremic Syndrome and C3 Glomerulopathy in Teens Transitioning to Young Adults. Adv Chronic Kidney Dis 2022; 29:231-242. [PMID: 36084970 DOI: 10.1053/j.ackd.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 04/11/2022] [Indexed: 11/11/2022]
Abstract
Atypical hemolytic uremic syndrome and C3 glomerulopathy/immune complex membranoproliferative glomerulonephritis are ultra-rare chronic, complement-mediated diseases with childhood manifestation in a majority of cases. Transition of clinical care of patients from pediatric to adult nephrologists-typically with controlled disease in native or transplant kidneys in case of atypical hemolytic uremic syndrome and often with chronic progressive disease despite treatment efforts in case of C3 glomerulopathy/immune complex membranoproliferative glomerulonephritis-identifies a challenging juncture in the journey of these patients. Raising awareness for the vulnerability of this patient cohort; providing education on disease pathophysiology and management including the use of new, high-precision complement antagonists; and establishing an ongoing dialog of patients, families, and all members of the health care team involved on either side of the age divide will be inevitable to ensure optimal patient outcomes and a safe transition of these patients to adulthood.
Collapse
Affiliation(s)
| | - Mina Matsuda-Abedini
- Division of Nephrology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatrics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Seetha Radhakrishnan
- Division of Nephrology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatrics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Michelle A Hladunewich
- Division of Nephrology and Obstetric Medicine, Department of Medicine, Sunnybrook Health Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Mathieu Lemaire
- Division of Nephrology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatrics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Chia Wei Teoh
- Division of Nephrology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatrics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Damien Noone
- Division of Nephrology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatrics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Christoph Licht
- Division of Nephrology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatrics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.
| |
Collapse
|