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Kavanagh D, Ardissino G, Brocklebank V, Bouwmeester RN, Bagga A, Ter Heine R, Johnson S, Licht C, Ma ALT, Noris M, Praga M, Rondeau E, Sinha A, Smith RJH, Sheerin NS, Trimarchi H, Wetzels JFM, Vivarelli M, Van de Kar NCAJ, Greenbaum LA. Outcomes from the International Society of Nephrology Haemolytic Uraemic Syndromes International Forum. Kidney Int 2024:S0085-2538(24)00705-1. [PMID: 39395628 DOI: 10.1016/j.kint.2024.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2024] [Revised: 08/07/2024] [Accepted: 09/04/2024] [Indexed: 10/14/2024]
Abstract
The haemolytic uraemic syndromes (HUS) are a heterogeneous group of conditions only some of which are mediated by complement (CaHUS). We report the outcome of the 2023 International Society of Nephrology HUS International Forum where a global panel of experts considered the current state of the art, identified areas of uncertainty, and proposed optimal solutions. Areas of uncertainty and areas for future research included: the nomenclature of HUS; novel complement testing strategies; identification of biomarkers; genetic predisposition to aHUS; optimal dosing and withdrawal strategies for C5 inhibitors; treatment of kidney transplantation recipients; disparity of access to treatment; and the next generation of complement inhibitors in CaHUS. The current rationale for optimal patient management is described.
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Affiliation(s)
- D Kavanagh
- National Renal Complement Therapeutics Centre, Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom; Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
| | - G Ardissino
- Center for HUS Prevention, Control and Management Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - V Brocklebank
- National Renal Complement Therapeutics Centre, Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom; Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - R N Bouwmeester
- Radboud University Medical Center, Amalia Children's Hospital, Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Nijmegen, Netherlands
| | - A Bagga
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - R Ter Heine
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands
| | - S Johnson
- National Renal Complement Therapeutics Centre, Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom; Great North Children's Hospital, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle, United Kingdom
| | - C Licht
- Division of Nephrology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - A L T Ma
- Paediatric Nephrology Centre, Hong Kong Children's Hospital, Hong Kong, China; Department of Pediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China
| | - M Noris
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases Aldo e Cele Daccò, Ranica, Italy
| | - M Praga
- Department of Nephrology, Instituto de Investigación Hospital 12 de Octubre (imas12), Madrid, Spain; Medicine Department, Universidad Complutense de Madrid, Madrid, Spain
| | - E Rondeau
- Intensive Care Nephrology and Transplantation Department, Hôpital Tenon, Assistance Publique-Hôpitaux de Paris (AP-HP) and Sorbonne Université, Paris, France
| | - A Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - R J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, The University of Iowa, Iowa City, IA, USA
| | - N S Sheerin
- National Renal Complement Therapeutics Centre, Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom; Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - H Trimarchi
- Nephrology Service, Hospital Britanico de Buenos Aires, Buenos Aires C1280 AEB, Argentina
| | - J F M Wetzels
- Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Nephrology, Nijmegen, Netherlands
| | - M Vivarelli
- Division of Nephrology, Laboratory of Nephrology, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
| | - N C A J Van de Kar
- Radboud University Medical Center, Amalia Children's Hospital, Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Nijmegen, Netherlands
| | - L A Greenbaum
- Division of Pediatric Nephrology, Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia, USA.
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Vivarelli M, Barratt J, Beck LH, Fakhouri F, Gale DP, Goicoechea de Jorge E, Mosca M, Noris M, Pickering MC, Susztak K, Thurman JM, Cheung M, King JM, Jadoul M, Winkelmayer WC, Smith RJH. The role of complement in kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference. Kidney Int 2024; 106:369-391. [PMID: 38844295 DOI: 10.1016/j.kint.2024.05.015] [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: 12/22/2023] [Revised: 04/25/2024] [Accepted: 05/22/2024] [Indexed: 06/22/2024]
Abstract
Uncontrolled complement activation can cause or contribute to glomerular injury in multiple kidney diseases. Although complement activation plays a causal role in atypical hemolytic uremic syndrome and C3 glomerulopathy, over the past decade, a rapidly accumulating body of evidence has shown a role for complement activation in multiple other kidney diseases, including diabetic nephropathy and several glomerulonephritides. The number of available complement inhibitor therapies has also increased during the same period. In 2022, Kidney Diseases: Improving Global Outcomes (KDIGO) convened a Controversies Conference, "The Role of Complement in Kidney Disease," to address the expanding role of complement dysregulation in the pathophysiology, diagnosis, and management of various glomerular diseases, diabetic nephropathy, and other forms of hemolytic uremic syndrome. Conference participants reviewed the evidence for complement playing a primary causal or secondary role in progression for several disease states and considered how evidence of complement involvement might inform management. Participating patients with various complement-mediated diseases and caregivers described concerns related to life planning, implications surrounding genetic testing, and the need for inclusive implementation of effective novel therapies into clinical practice. The value of biomarkers in monitoring disease course and the role of the glomerular microenvironment in complement response were examined, and key gaps in knowledge and research priorities were identified.
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Affiliation(s)
- Marina Vivarelli
- Laboratory of Nephrology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
| | - Jonathan Barratt
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Laurence H Beck
- Section of Nephrology, Department of Medicine, Boston University Chobanian & Avedisian School of Medicine and Boston Medical Center, Boston, Massachusetts, USA
| | - Fadi Fakhouri
- Department of Nephrology, Centre Hospitalier Universitaire, Nantes, France; INSERM UMR S1064, Nantes, France
| | - Daniel P Gale
- Centre for Kidney and Bladder Health, University College London, UK
| | - Elena Goicoechea de Jorge
- Department of Immunology, Ophthalmology and ORL, Complutense University, Madrid, Spain; Area of Chronic Diseases and Transplantation, Research Institute Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Marta Mosca
- Department of Clinical and Experimental Medicine-Rheumatology Unit, University of Pisa, Pisa, Italy
| | - Marina Noris
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Ranica, Italy
| | - Matthew C Pickering
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College, Hammersmith Campus, London, UK
| | - Katalin Susztak
- Division of Nephrology, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Joshua M Thurman
- Division of Nephrology and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | | | | | - Michel Jadoul
- Cliniques Universitaires Saint Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Wolfgang C Winkelmayer
- Selzman Institute for Kidney Health, Section of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; Department of Internal Medicine, Division of Nephrology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; Department of Pediatrics, Division of Nephrology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
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3
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Obata S, Hullekes F, Riella LV, Cravedi P. Recurrent complement-mediated Hemolytic uremic syndrome after kidney transplantation. Transplant Rev (Orlando) 2024; 38:100857. [PMID: 38749097 DOI: 10.1016/j.trre.2024.100857] [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: 03/13/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 06/16/2024]
Abstract
Hereditary forms of hemolytic uremic syndrome (HUS), formerly known as atypical HUS, typically involve mutations in genes encoding for components of the alternative pathway of complement, therefore they are often referred to as complement-mediated HUS (cHUS). This condition has a high risk of recurrence in the transplanted kidney, leading to accelerated graft loss. The availability of anti-complement component C5 antibody eculizumab has enabled successful transplantation with a notably reduced recurrence rate and improved prognosis. Open questions are related to the potential for complement inhibitor discontinuation, ideal timing of treatment withdrawal, and patient selection based on genetic abnormalities. Our review delves into the pathophysiology, classification, genetic predispositions, and management strategies for cHUS in the native and transplant kidneys.
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Affiliation(s)
- Shota Obata
- Precision Immunology Institute, Translational Transplant Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - Frank Hullekes
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Leonardo V Riella
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America; Department of Medicine, Nephrology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Paolo Cravedi
- Precision Immunology Institute, Translational Transplant Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America.
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Bouwmeester RN, Engel LJ, Altena W, Renette C, van Daelen C, van Kempen E, de Wildt R, van de Kar NC. Living with Atypical Hemolytic Uremic Syndrome in the Netherlands: Patient and Family Perspective. Kidney Int Rep 2024; 9:2189-2197. [PMID: 39081735 PMCID: PMC11284443 DOI: 10.1016/j.ekir.2024.04.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 04/09/2024] [Accepted: 04/17/2024] [Indexed: 08/02/2024] Open
Abstract
Introduction Atypical hemolytic uremic syndrome (aHUS) poses a significant health challenge due to its rarity and severity within the spectrum of thrombotic microangiopathy. Despite efforts to optimize and personalize health care for patients with aHUS, understanding the individual experiences, needs, and desires of patients with aHUS and their relatives remains limited. Methods Here, we present a nationwide, exploratory, qualitative interview study with a direct content analysis approach. In-depth interviews and a 6-week evaluation were audio-recorded and conducted using a semistructured topic guide, based on the Institute for Positive Health (IPH) model. Results Analysis of 10 interviews involving 6 patients with aHUS and 13 relatives revealed the prevalence of long-term disease symptoms in adult patients, notably fatigue, which significantly impacted daily functioning. Moreover, the resilience demonstrated by patients and their relatives was noteworthy; however, the acute phase of aHUS and the unpredictable nature of disease recurrence could profoundly affect mental well-being. The emotional toll of aHUS is pervasive, with feelings of fear, guilt, and trauma persisting across disease phases in both patients and relatives. Challenges in medical care, including delays in diagnosis and the need for personalized and uniform protocols, were highlighted. Support was deemed crucial, indicating the necessity for enhancements in the accessibility to comprehensible disease information and psychological counseling. Finally, complexities surrounding genetic testing and carriership were discussed. Conclusion This study underscores the profound, enduring, and multifaced impact of aHUS. The insights gleaned from the experiences and needs of patients with aHUS and their relatives could lay the foundation for development and implementation of more personalized innovations in aHUS health care.
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Affiliation(s)
- Romy N. Bouwmeester
- Radboud University Medical Center, Amalia Children’s Hospital, Department of Pediatric Nephrology, Nijmegen, Netherlands
| | - Leonie J. Engel
- Radboud University Medical Center, Amalia Children’s Hospital, Department of Pediatric Nephrology, Nijmegen, Netherlands
| | - Wim Altena
- Dutch Kidney Patients Association, Bussum, Netherlands
| | | | - Clim van Daelen
- Dutch Kidney Patients Association, Bussum, Netherlands
- The Netherlands Patients Federation, Utrecht, Netherlands
| | | | | | - Nicole C.A.J. van de Kar
- Radboud University Medical Center, Amalia Children’s Hospital, Department of Pediatric Nephrology, Nijmegen, Netherlands
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Leisring J, Brodsky SV, Parikh SV. Clinical Evaluation and Management of Thrombotic Microangiopathy. Arthritis Rheumatol 2024; 76:153-165. [PMID: 37610060 DOI: 10.1002/art.42681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/17/2023] [Accepted: 08/17/2023] [Indexed: 08/24/2023]
Abstract
Thrombotic microangiopathy (TMA) refers to a diverse group of diseases that share clinical and histopathologic features. TMA is clinically characterized by microangiopathic hemolytic anemia, consumptive thrombocytopenia, and organ injury that stems from endothelial damage and vascular occlusion. There are several disease states with distinct pathophysiological mechanisms that manifest as TMA. These conditions are associated with significant morbidity and mortality and require urgent recognition and treatment. Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are traditionally considered to be primary forms of TMA, but TMA more commonly occurs in association with a coexisting condition such as infection, pregnancy, autoimmune disease, or malignant hypertension, among others. Determining the cause of TMA is a diagnostic challenge because of limited availability of disease-specific testing. However, identifying the underlying etiology is imperative as treatment strategies differ. Our understanding of the conditions that cause TMA is evolving. Recent advances have led to improved comprehension of the varying pathogenic mechanisms that drive TMA. Development of targeted therapeutics has resulted in significant improvements in patient outcomes. In this article, we review the pathogenesis and clinical features of the different TMA-causing conditions. We outline a practical approach to diagnosis and management and discuss empiric and disease-specific treatment strategies.
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Affiliation(s)
- Joshua Leisring
- The Ohio State University Wexner Medical Center, Columbus, Ohio
| | | | - Samir V Parikh
- The Ohio State University Wexner Medical Center, Columbus, Ohio
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Wehrmann F, von Bergwelt-Baildon A, Schönermarck U. Severe hypertension and (renal) thrombotic microangiopathy: solving the puzzle. J Nephrol 2023; 36:2175-2177. [PMID: 37256539 PMCID: PMC10638162 DOI: 10.1007/s40620-023-01659-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 04/28/2023] [Indexed: 06/01/2023]
Affiliation(s)
- Florian Wehrmann
- Department of Medicine IV, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Anke von Bergwelt-Baildon
- Department of Medicine IV, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Ulf Schönermarck
- Department of Medicine IV, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany.
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Turudic D, Pokrajac D, Tasic V, Kasumovic D, Prohaszka Z, Milosevic D. The Rationale of Complement Blockade of the MCP ggaac Haplotype following Atypical Hemolytic Uremic Syndrome of Three Southeastern European Countries with a Literature Review. Int J Mol Sci 2023; 24:13041. [PMID: 37685848 PMCID: PMC10487996 DOI: 10.3390/ijms241713041] [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: 07/11/2023] [Revised: 08/10/2023] [Accepted: 08/16/2023] [Indexed: 09/10/2023] Open
Abstract
We present eight cases of the homozygous MCPggaac haplotype, which is considered to increase the likelihood and severity of atypical hemolytic uremic syndrome (aHUS), especially in combination with additional risk aHUS mutations. Complement blockade (CBT) was applied at a median age of 92 months (IQR 36-252 months). The median number of relapses before CBT initiation (Eculizumab) was two. Relapses occurred within an average of 22.16 months (median 17.5, minimum 8 months, and maximum 48 months) from the first subsequent onset of the disease (6/8 patients). All cases were treated with PI/PEX, and rarely with renal replacement therapy (RRT). When complement blockade was applied, children had no further disease relapses. Children with MCPggaac haplotype with/without additional gene mutations can achieve remission through renal replacement therapy without an immediate need for complement blockade. If relapse of aHUS occurs soon after disease onset or relapses are repeated frequently, a permanent complement blockade is required. However, the duration of such a blockade remains uncertain. If complement inhibition is not applied within 4-5 relapses, proteinuria and chronic renal failure will eventually occur.
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Affiliation(s)
- Daniel Turudic
- Department of Pediatrics, University Hospital Centre Zagreb, Kispaticeva 12, 10000 Zagreb, Croatia
| | - Danka Pokrajac
- Pediatric Clinic, Clinical Center, University of Sarajevo, Patriotske Lige 81, 71000 Sarajevo, Bosnia and Herzegovina;
| | - Velibor Tasic
- Medical Faculty Skopje, University Children’s Hospital, 1010 Skopje, North Macedonia;
| | - Dino Kasumovic
- Department of Nephrology and Dialysis, Dubrava University Hospital, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia;
| | - Zoltan Prohaszka
- Department of Internal Medicine and Hematology, Semmelweis University, 1085 Budapest, Hungary;
- Research Group for Immunology and Haematology, Eotvos Lorand Research Network (Office for Supported Research Groups), Semmelweis University, 1085 Budapest, Hungary
| | - Danko Milosevic
- Croatian Academy of Medical Sciences, Kaptol ul. 15, 10000 Zagreb, Croatia;
- Department of Pediatrics, Zabok General Hospital, and the Croatian Veterans Hospital, Bračak 8, 49210 Bračak, Croatia
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Holers VM. Complement therapeutics are coming of age in rheumatology. Nat Rev Rheumatol 2023; 19:470-485. [PMID: 37337038 DOI: 10.1038/s41584-023-00981-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2023] [Indexed: 06/21/2023]
Abstract
The complement system was described over 100 years ago, and it is well established that activation of this pathway accompanies the great majority of autoimmune and inflammatory diseases. In addition, over three decades of work in murine models of human disease have nearly universally demonstrated that complement activation is upstream of tissue injury and the engagement of pro-inflammatory mechanisms such as the elaboration of cytokines and chemokines, as well as myeloid cell recruitment and activation. With that background, and taking advantage of advances in the development of biologic and small-molecule therapeutics, the creation and clinical evaluation of complement therapeutics is now rapidly expanding. This article reviews the current state of the complement therapeutics field, with a focus on their use in diseases cared for or consulted upon by rheumatologists. Included is an overview of the activation mechanisms and components of the system, in addition to the mechanisms by which the complement system interacts with other immune system constituents. The various therapeutic approaches to modulating the system in rheumatic and autoimmune diseases are reviewed. To understand how best to clinically assess the complement system, methods of its evaluation are described. Finally, next-generation therapeutic and diagnostic advances that can be envisioned for the future are discussed.
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Affiliation(s)
- V Michael Holers
- Medicine/Rheumatology, University of Colorado School of Medicine, Aurora, CO, USA.
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Donadelli R, Sinha A, Bagga A, Noris M, Remuzzi G. HUS and TTP: traversing the disease and the age spectrum. Semin Nephrol 2023; 43:151436. [PMID: 37949684 DOI: 10.1016/j.semnephrol.2023.151436] [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] [Indexed: 11/12/2023]
Abstract
Hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenia purpura (TTP) are rare diseases sharing a common pathological feature, thrombotic microangiopathy (TMA). TMA is characterized by microvascular thrombosis with consequent thrombocytopenia, microangiopathic hemolytic anemia and/or multiorgan dysfunction. In the past, the distinction between HUS and TTP was predominantly based on clinical grounds. However, clinical presentation of the two syndromes often overlaps and, the differential diagnosis is broad. Identification of underlying pathogenic mechanisms has enabled the classification of these syndromes on a molecular basis: typical HUS caused by Shiga toxin-producing Escherichia coli (STEC-HUS); atypical HUS or complement-mediated TMA (aHUS/CM-TMA) associated with genetic or acquired defects leading to dysregulation of the alternative pathway (AP) of complement; and TTP that results from a severe deficiency of the von Willebrand Factor (VWF)-cleaving protease, ADAMTS13. The etiology of TMA differs between pediatric and adult patients. Childhood TMA is chiefly caused by STEC-HUS, followed by CM-TMA and pneumococcal HUS (Sp-HUS). Rare conditions such as congenital TTP (cTTP), vitamin B12 metabolism defects, and coagulation disorders (diacylglycerol epsilon mutation) present as TMA chiefly in children under 2 years of age. In contrast secondary causes and acquired ADAMT13 deficiency are more common in adults. In adults, compared to children, diagnostic delays are more frequent due to the wide range of differential diagnoses. In this review we focus on the three major forms of TMA, STEC-HUS, aHUS and TTP, outlining the clinical presentation, diagnosis and management of the affected patients, to help highlight the salient features and the differences between adult and pediatric patients which are relevant for management.
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Affiliation(s)
- Roberta Donadelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases Aldo e Cele Daccò, Ranica, Italy
| | - Aditi Sinha
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi
| | - Arvind Bagga
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi
| | - Marina Noris
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases Aldo e Cele Daccò, Ranica, Italy
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases Aldo e Cele Daccò, Ranica, Italy.
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Gastoldi S, Aiello S, Galbusera M, Breno M, Alberti M, Bresin E, Mele C, Piras R, Liguori L, Santarsiero D, Benigni A, Remuzzi G, Noris M. An ex vivo test to investigate genetic factors conferring susceptibility to atypical haemolytic uremic syndrome. Front Immunol 2023; 14:1112257. [PMID: 36845135 PMCID: PMC9949374 DOI: 10.3389/fimmu.2023.1112257] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/20/2023] [Indexed: 02/11/2023] Open
Abstract
Introduction Comprehensive genetic analysis is essential to clinical care of patients with atypical haemolytic uremic syndrome (aHUS) to reinforce diagnosis, and to guide treatment. However, the characterization of complement gene variants remains challenging owing to the complexity of functional studies with mutant proteins. This study was designed: 1) To identify a tool for rapid functional determination of complement gene variants; 2) To uncover inherited complement dysregulation in aHUS patients who do not carry identified gene variants. Methods To address the above goals, we employed an ex-vivo assay of serum-induced C5b-9 formation on ADP-activated endothelial cells in 223 subjects from 60 aHUS pedigrees (66 patients and 157 unaffected relatives). Results Sera taken from all aHUS patients in remission induced more C5b-9 deposition than control sera, independently from the presence of complement gene abnormalities. To avoid the possible confounding effects of chronic complement dysregulation related to aHUS status, and considering the incomplete penetrance for all aHUS-associated genes, we used serum from unaffected relatives. In control studies, 92.7% of unaffected relatives with known pathogenic variants exhibited positive serum-induced C5b-9 formation test, documenting a high sensitivity of the assay to identify functional variants. The test was also specific, indeed it was negative in all non-carrier relatives and in relatives with variants non-segregating with aHUS. All but one variants in aHUS-associated genes predicted in-silico as likely pathogenic or of uncertain significance (VUS) or likely benign resulted as pathogenic in the C5b-9 assay. At variance, variants in putative candidate genes did not exhibit a functional effect, with the exception of a CFHR5 variant. The C5b-9 assay in relatives was helpful in defining the relative functional effect of rare variants in 6 pedigrees in which the proband carried more than one genetic abnormality. Finally, for 12 patients without identified rare variants, the C5b-9 test in parents unmasked a genetic liability inherited from an unaffected parent. Discussion In conclusion, the serum-induced C5b-9 formation test in unaffected relatives of aHUS patients may be a tool for rapid functional evaluation of rare complement gene variants. When combined with exome sequencing the assay might be of help in variant selection, to identify new aHUS-associated genetic factors.
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Affiliation(s)
- Sara Gastoldi
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Sistiana Aiello
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Miriam Galbusera
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Matteo Breno
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Marta Alberti
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elena Bresin
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Caterina Mele
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Rossella Piras
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Lucia Liguori
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Donata Santarsiero
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Ariela Benigni
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Giuseppe Remuzzi
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
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11
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Piras R, Valoti E, Alberti M, Bresin E, Mele C, Breno M, Liguori L, Donadelli R, Rigoldi M, Benigni A, Remuzzi G, Noris M. CFH and CFHR structural variants in atypical Hemolytic Uremic Syndrome: Prevalence, genomic characterization and impact on outcome. Front Immunol 2023; 13:1011580. [PMID: 36793547 PMCID: PMC9923232 DOI: 10.3389/fimmu.2022.1011580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 12/28/2022] [Indexed: 01/31/2023] Open
Abstract
Introduction Atypical hemolytic uremic syndrome (aHUS) is a rare disease that manifests with microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure, and is associated with dysregulation of the alternative complement pathway. The chromosomal region including CFH and CFHR1-5 is rich in repeated sequences, favoring genomic rearrangements that have been reported in several patients with aHUS. However, there are limited data on the prevalence of uncommon CFH-CFHR genomic rearrangements in aHUS and their impact on disease onset and outcomes. Methods In this study, we report the results of CFH-CFHR Copy Number Variation (CNV) analysis and the characterization of resulting structural variants (SVs) in a large cohort of patients, including 258 patients with primary aHUS and 92 with secondary forms. Results We found uncommon SVs in 8% of patients with primary aHUS: 70% carried rearrangements involving CFH alone or CFH and CFHR (group A; n=14), while 30% exhibited rearrangements including only CFHRs (group B; n=6). In group A, 6 patients presented CFH::CFHR1 hybrid genes, 7 patients carried duplications in the CFH-CFHR region that resulted either in the substitution of the last CFHR1 exon(s) with those of CFH (CFHR1::CFH reverse hybrid gene) or in an internal CFH duplication. In group A, the large majority of aHUS acute episodes not treated with eculizumab (12/13) resulted in chronic ESRD; in contrast, anti-complement therapy induced remission in 4/4 acute episodes. aHUS relapse occurred in 6/7 grafts without eculizumab prophylaxis and in 0/3 grafts with eculizumab prophylaxis. In group B, 5 subjects had the CFHR31-5::CFHR410 hybrid gene and one had 4 copies of CFHR1 and CFHR4. Compared with group A, patients in group B exhibited a higher prevalence of additional complement abnormalities and earlier disease onset. However, 4/6 patients in this group underwent complete remission without eculizumab treatment. In secondary forms we identified uncommon SVs in 2 out of 92 patients: the CFHR31-5::CFHR410 hybrid and a new internal duplication of CFH. Discussion In conclusion, these data highlight that uncommon CFH-CFHR SVs are frequent in primary aHUS and quite rare in secondary forms. Notably, genomic rearrangements involving the CFH are associated with a poor prognosis but carriers respond to anti-complement therapy.
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12
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de Boer ECW, Thielen AJF, Langereis JD, Kamp A, Brouwer MC, Oskam N, Jongsma ML, Baral AJ, Spaapen RM, Zeerleder S, Vidarsson G, Rispens T, Wouters D, Pouw RB, Jongerius I. The contribution of the alternative pathway in complement activation on cell surfaces depends on the strength of classical pathway initiation. Clin Transl Immunology 2023; 12:e1436. [PMID: 36721662 PMCID: PMC9881211 DOI: 10.1002/cti2.1436] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 10/31/2022] [Accepted: 12/23/2022] [Indexed: 01/28/2023] Open
Abstract
Objectives The complement system is an important component of innate immunity. The alternative pathway (AP) amplification loop is considered an essential feed forward mechanism for complement activation. However, the role of the AP in classical pathway (CP) activation has only been studied in ELISA settings. Here, we investigated its contribution on physiologically relevant surfaces of human cells and bacterial pathogens and in antibody-mediated complement activation, including in autoimmune haemolytic anaemia (AIHA) setting with autoantibodies against red blood cells (RBCs). Methods We evaluated the contribution of the AP to complement responses initiated through the CP on human RBCs by serum of AIHA patients and recombinant antibodies. Moreover, we studied complement activation on Neisseria meningitidis and Escherichia coli. The effect of the AP was examined using either AP-depleted sera or antibodies against factor B and factor D. Results We show that the amplification loop is redundant when efficient CP activation takes place. This is independent of the presence of membrane-bound complement regulators. The role of the AP may become significant when insufficient CP complement activation occurs, but this depends on antibody levels and (sub)class. Our data indicate that therapeutic intervention in the amplification loop will most likely not be effective to treat antibody-mediated diseases. Conclusion The AP can be bypassed through efficient CP activation. The AP amplification loop has a role in complement activation during conditions of modest activation via the CP, when it can allow for efficient complement-mediated killing.
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Affiliation(s)
- Esther CW de Boer
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's HospitalAmsterdam University Medical CentreAmsterdamThe Netherlands
| | - Astrid JF Thielen
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Jeroen D Langereis
- Laboratory of Medical Immunology, Radboud Institute for Molecular Life SciencesRadboudumcNijmegenThe Netherlands,Radboud Center for Infectious Diseases, RadboudumcNijmegenThe Netherlands
| | - Angela Kamp
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Mieke C Brouwer
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Nienke Oskam
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Marlieke L Jongsma
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - April J Baral
- Translational and Clinical Research InstituteNewcastle upon TyneUK
| | - Robbert M Spaapen
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Sacha Zeerleder
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Department of Hematology, Luzerner KantonsspitalLuzern and University of BernBernSwitzerland,Department for BioMedical ResearchUniversity of BernBernSwitzerland
| | - Gestur Vidarsson
- Department of Experimental Immunohematology, Sanquin Research, and Landsteiner LaboratoryAmsterdam University Medical CenterAmsterdamThe Netherlands
| | - Theo Rispens
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands
| | - Diana Wouters
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Centre for Infectious Disease ControlNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | - Richard B Pouw
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Sanquin Health SolutionsAmsterdamThe Netherlands
| | - Ilse Jongerius
- Department of Immunopathology, Sanquin Research and Landsteiner LaboratoryAmsterdam Infection and Immunity Institute, Amsterdam University Medical CentreAmsterdamThe Netherlands,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's HospitalAmsterdam University Medical CentreAmsterdamThe Netherlands
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13
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Rodríguez de Córdoba S. Genetic variability shapes the alternative pathway complement activity and predisposition to complement-related diseases. Immunol Rev 2023; 313:71-90. [PMID: 36089777 PMCID: PMC10086816 DOI: 10.1111/imr.13131] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The implementation of next-generation sequencing technologies has provided a sharp picture of the genetic variability in the components and regulators of the alternative pathway (AP) of the complement system and has revealed the association of many AP variants with different rare and common diseases. An important finding that has emerged from these analyses is that each of these complement-related diseases associate with genetic variants altering specific aspects of the activation and regulation of the AP. These genotype-phenotype correlations have provided valuable insights into their pathogenic mechanisms with important diagnostic and therapeutic implications. While genetic variants in coding regions and structural variants are reasonably well characterized and occasionally have been instrumental to uncover unknown features of the complement proteins, data about complement expressed quantitative trait loci are still very limited. A crucial task for future studies will be to identify these quantitative variations and to determine their impact in the overall activity of the AP. This is fundamental as it is now clear that the consequences of genetic variants in the AP are additive and that susceptibility or resistance to disease is the result of specific combinations of genetic variants in different complement components and regulators ("complotypes").
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14
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Abstract
Dysregulation and accelerated activation of the alternative pathway (AP) of complement is known to cause or accentuate several pathologic conditions in which kidney injury leads to the appearance of hematuria and proteinuria and ultimately to the development of chronic renal failure. Multiple genetic and acquired defects involving plasma- and membrane-associated proteins are probably necessary to impair the protection of host tissues and to confer a significant predisposition to AP-mediated kidney diseases. This review aims to explore how our current understanding will make it possible to identify the mechanisms that underlie AP-mediated kidney diseases and to discuss the available clinical evidence that supports complement-directed therapies. Although the value of limiting uncontrolled complement activation has long been recognized, incorporating complement-targeted treatments into clinical use has proved challenging. Availability of anti-complement therapy has dramatically transformed the outcome of atypical hemolytic uremic syndrome, one of the most severe kidney diseases. Innovative drugs that directly counteract AP dysregulation have also opened new perspectives for the management of other kidney diseases in which complement activation is involved. However, gained experience indicates that the choice of drug should be tailored to each patient's characteristics, including clinical, histologic, genetic, and biochemical parameters. Successfully treating patients requires further research in the field and close collaboration between clinicians and researchers who have special expertise in the complement system.
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Affiliation(s)
- Erica Daina
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Monica Cortinovis
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
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15
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Prével R, Delmas Y, Guillotin V, Gruson D, Rivière E. Complement Blockade Is a Promising Therapeutic Approach in a Subset of Critically Ill Adult Patients with Complement-Mediated Hemolytic Uremic Syndromes. J Clin Med 2022; 11:jcm11030790. [PMID: 35160242 PMCID: PMC8837052 DOI: 10.3390/jcm11030790] [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: 12/30/2021] [Revised: 01/24/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023] Open
Abstract
Thrombotic microangiopathy (TMA) gathers consumptive thrombocytopenia, mechanical haemolytic anemia, and organ damage. Hemolytic uremic syndromes (HUS) are historically classified as primary or secondary to another disease once thrombotic thrombocytopenic purpura (TTP), Shiga-toxin HUS, and cobalamin C-related HUS have been ruled out. Complement genetics studies reinforced the link between complement dysregulation and primary HUS, contributing to reclassifying some pregnancy- and/or post-partum-associated HUS and to revealing complement involvement in severe and/or refractory hypertensive emergencies. By contrast, no firm evidence allows a plausible association to be drawn between complement dysregulation and Shiga-toxin HUS or other secondary HUS. Nevertheless, rare complement gene variants are prevalent in healthy individuals, thus providing an indication that an investigation into complement dysregulation should be carefully balanced and that the results should be cautiously interpreted with the help of a trained geneticist. Several authors have suggested reclassifying HUS in two entities, regardless of they are complement-mediated or not, since the use of eculizumab, an anti-C5 antibody, dramatically lowers the proportion of patients who die or suffer from end-stage renal disease within the year following diagnosis. Safety and the ideal timing of eculizumab discontinuation is currently under investigation, and the long-term consequences of HUS should be closely monitored over time once patients exit emergency departments.
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Affiliation(s)
- Renaud Prével
- CHU Bordeaux, Medical Intensive Care Unit, F-33000 Bordeaux, France; (V.G.); (D.G.)
- University Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Inserm UMR 1045, F-33000 Bordeaux, France
- Correspondence: ; Tel.: +33-(0)5-56-79-55-17; Fax: +33-(0)5-56-79-54-18
| | - Yahsou Delmas
- CHU Bordeaux, Nephrology Transplantation Dialysis Apheresis Unit, F-33076 Bordeaux, France;
| | - Vivien Guillotin
- CHU Bordeaux, Medical Intensive Care Unit, F-33000 Bordeaux, France; (V.G.); (D.G.)
| | - Didier Gruson
- CHU Bordeaux, Medical Intensive Care Unit, F-33000 Bordeaux, France; (V.G.); (D.G.)
- University Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, Inserm UMR 1045, F-33000 Bordeaux, France
| | - Etienne Rivière
- CHU Bordeaux, Internal Medicine Department, F-33000 Bordeaux, France;
- University Bordeaux, Biology of Cardiovascular Diseases, InsermU1034, F-33604 Pessac, France
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16
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Familial Atypical Hemolytic Uremic Syndrome with Positive p.S1191L (c.3572C>T) Mutation on the CFH Gene: A Single-center Experience. Balkan J Med Genet 2021; 24:81-88. [PMID: 34447663 PMCID: PMC8366473 DOI: 10.2478/bjmg-2021-0007] [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] [Indexed: 11/20/2022] Open
Abstract
The atypical hemolytic uremic syndrome (aHUS) is characterized by thrombocytopenia, microangiopathic hemolytic anemia and acute kidney injury (AKI), which can exhibit a poor prognosis. Complement factor H (CFH) gene mutations play a key role in this disease, which may be sporadic or familial. We studied 13 people from the same family, investigated for gene mutations of the familial aHUS after a family member presented to our emergency clinic with the aHUS and reported a family history of chronic renal failure. The p.S1191L mutation on the CFH gene was heterozygous in six people from the patient’s family with the aHUS. One of these family members is our patient with acute kidney injury, and the other two are followed at the Nephrology Clinic, Medeniyat University, Goztepe Training and Research Hospital, Istanbul, Turkey, due to chronic renal failure. The other three family members showed no evidence of renal failure. The index case had a history of six sibling deaths; three died of chronic renal failure. Plasmapheresis and fresh frozen plasma treatment were administered to our patient. When the patient showed no response to this treatment, eculizumab (ECZ) therapy was started. The study demonstrated that thorough family history should be taken in patients with the aHUS. These patients may have the familial type of the disease, and they should be screened genetically. Eculizumab should be the first choice in the treatment with plasmapheresis. It should be kept in mind that the use of ECZ as prophylaxis in posttransplant therapy is extremely important for preventing rejection.
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Fakhouri F, Frémeaux-Bacchi V. Thrombotic microangiopathy in aHUS and beyond: clinical clues from complement genetics. Nat Rev Nephrol 2021; 17:543-553. [PMID: 33953366 DOI: 10.1038/s41581-021-00424-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2021] [Indexed: 02/02/2023]
Abstract
Studies of complement genetics have changed the landscape of thrombotic microangiopathies (TMAs), particularly atypical haemolytic uraemic syndrome (aHUS). Knowledge of complement genetics paved the way for the design of the first specific treatment for aHUS, eculizumab, and is increasingly being used to aid decisions regarding discontinuation of anti-complement treatment in this setting. Complement genetic studies have also been used to investigate the pathogenic mechanisms that underlie other forms of HUS and provided evidence that contributed to the reclassification of pregnancy- and postpartum-associated HUS within the spectrum of complement-mediated aHUS. By contrast, complement genetics has not provided definite evidence of a link between constitutional complement dysregulation and secondary forms of HUS. Therefore, the available data do not support systematic testing of complement genes in patients with typical HUS or secondary HUS. The potential relevance of complement genetics for distinguishing the underlying mechanisms of malignant hypertension-associated TMA should be assessed with caution owing to the overlap between aHUS and other causes of malignant hypertension. In all cases, the interpretation of complement genetics results remains complex, as even complement-mediated aHUS is not a classical monogenic disease. Such interpretation requires the input of trained geneticists and experts who have a comprehensive view of complement biology.
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Affiliation(s)
- Fadi Fakhouri
- Service of Nephrology and Hypertension, Department of Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
| | - Véronique Frémeaux-Bacchi
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service d'Immunologie, Paris, France
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18
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Sánchez-Moreno A, de la Cerda F, Rodríguez-Barba A, Fijo J, Bedoya R, Arjona E, de Córdoba SR. Is the atypical hemolytic uremic syndrome risk polymorphism in Membrane Cofactor Protein MCPggaac relevant in kidney transplantation? A case report. Pediatr Transplant 2021; 25:e13903. [PMID: 33217135 DOI: 10.1111/petr.13903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 09/08/2020] [Accepted: 10/06/2020] [Indexed: 12/26/2022]
Abstract
aHUS is a rare disease characterized by episodes of TMA that frequently progresses to CKD and often recurs after KT. The most frequent cause of aHUS is defective regulation of complement activation because of genetic anomalies. Eculizumab interrupts the process of TMA and improves renal function. We describe one female patient with aHUS who debuted in 2005 at 3-mo-old with extrarenal manifestations and progressed to end-stage kidney disease (ESKD) within a year. Her family history included several affected members with similar bad outcomes. Our patient carries a strong aHUS genetic predisposition consisting in a pathogenic gain-of-function mutation in complement factor B concurrent with the MCP aHUS risk haplotype MCPggaac. She received a kidney transplant in 2011 without eculizumab prophylaxis. The graft, which was negative for the MCPggaac risk haplotype, had an unexpected excellent evolution without aHUS recurrence. Different retrospective studies have shown that the risk of aHUS recurrence after KT correlates well with the genetic load of aHUS risk factors. Knowing important contribution of the MCPggaac risk haplotype to the risk of developing aHUS in Factor B mutations carriers, we speculate whether the absence of this polymorphism in the graft that our patient received may have decreased the risk of aHUS recurrence after KT.
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Affiliation(s)
- Ana Sánchez-Moreno
- Pediatric Nephrology Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | | | | | - Julia Fijo
- Pediatric Nephrology Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | - Rafael Bedoya
- Pediatric Nephrology Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | - Emilia Arjona
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Enfermedades Raras, Madrid, Spain
| | - Santiago Rodríguez de Córdoba
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Enfermedades Raras, Madrid, Spain
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19
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Timmermans SAMEG, Damoiseaux JGMC, Werion A, Reutelingsperger CP, Morelle J, van Paassen P. Functional and Genetic Landscape of Complement Dysregulation Along the Spectrum of Thrombotic Microangiopathy and its Potential Implications on Clinical Outcomes. Kidney Int Rep 2021; 6:1099-1109. [PMID: 33912760 PMCID: PMC8071658 DOI: 10.1016/j.ekir.2021.01.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 01/25/2021] [Indexed: 01/30/2023] Open
Abstract
Introduction The syndromes of thrombotic microangiopathy (TMA) are diverse and represent severe endothelial damage caused by various mechanisms. The complement system plays a major role in a subset of patients with TMA, and its recognition is of clinical importance because it guides choice and duration of treatment. Methods We studied a well-defined cohort of patients with TMA and hypothesized that assessment of serum-induced ex vivo C5b9 formation on the endothelium and screening for rare variants in complement genes can better categorize TMA. Results Massive ex vivo C5b9 formation was found in all patients with primary atypical hemolytic uremic syndrome (n/N = 11/11) and in 59% of patients with TMA and coexisting conditions (n/N = 30/51). Massive ex vivo C5b9 formation was associated with rare genetic variants (45% [n/N = 20/44] vs. 0% [n/N = 0/21] patients with normal ex vivo C5b9 formation; P < 0.001). Massive ex vivo C5b9 formation was associated with favorable renal response to therapeutic complement inhibition in patients with TMA and coexisting conditions (86% [n/N = 12/14] vs. 31% [n/N = 5/16] of untreated patients; P < 0.001), indicating complement-mediated TMA rather than secondary disease. Among treated patients, the odds ratio for 1-year kidney survival was 12.0 (95% confidence interval 1.2-115.4). TMA recurrence was linked to rare genetic variants in all cases. Patients with normal ex vivo C5b9 formation had an acute, nonrelapsing form of TMA. Conclusions Ex vivo C5b9 formation and genetic testing appears to categorize TMAs into different groups because it identifies complement as a driving factor of disease, with potential therapeutic and prognostic implications.
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Affiliation(s)
- Sjoerd A M E G Timmermans
- Department of Nephrology and Clinical Immunology.,Department of Biochemistry, Cardiovascular Research Institute, Maastricht, The Netherlands
| | - Jan G M C Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Alexis Werion
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | | | - Johann Morelle
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.,Institut de Recherche Experimentale et Clinique, UCLouvain, Brussels, Belgium
| | - Pieter van Paassen
- Department of Nephrology and Clinical Immunology.,Department of Biochemistry, Cardiovascular Research Institute, Maastricht, The Netherlands
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20
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de Boer ECW, van Mourik AG, Jongerius I. Therapeutic Lessons to be Learned From the Role of Complement Regulators as Double-Edged Sword in Health and Disease. Front Immunol 2020; 11:578069. [PMID: 33362763 PMCID: PMC7758290 DOI: 10.3389/fimmu.2020.578069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/12/2020] [Indexed: 12/22/2022] Open
Abstract
The complement system is an important part of the innate immune system, providing a strong defense against pathogens and removing apoptotic cells and immune complexes. Due to its strength, it is important that healthy human cells are protected against damage induced by the complement system. To be protected from complement, each cell type relies on a specific combination of both soluble and membrane-bound regulators. Their importance is indicated by the amount of pathologies associated with abnormalities in these complement regulators. Here, we will discuss the current knowledge on complement regulatory protein polymorphisms and expression levels together with their link to disease. These diseases often result in red blood cell destruction or occur in the eye, kidney or brain, which are tissues known for aberrant complement activity or regulation. In addition, complement regulators have also been associated with different types of cancer, although their mechanisms here have not been elucidated yet. In most of these pathologies, treatments are limited and do not prevent the complement system from attacking host cells, but rather fight the consequences of the complement-mediated damage, using for example blood transfusions in anemic patients. Currently only few drugs targeting the complement system are used in the clinic. With further demand for therapeutics rising linked to the wide range of complement-mediated disease we should broaden our horizon towards treatments that can actually protect the host cells against complement. Here, we will discuss the latest insights on how complement regulators can benefit therapeutics. Such therapeutics are currently being developed extensively, and can be categorized into full-length complement regulators, engineered complement system regulators and antibodies targeting complement regulators. In conclusion, this review provides an overview of the complement regulatory proteins and their links to disease, together with their potential in the development of novel therapeutics.
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Affiliation(s)
- Esther C W de Boer
- Sanquin Research, Department of Immunopathology, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam Infection and Immunity Institute, Amsterdam, Netherlands.,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, Netherlands
| | - Anouk G van Mourik
- Sanquin Research, Department of Immunopathology, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam Infection and Immunity Institute, Amsterdam, Netherlands
| | - Ilse Jongerius
- Sanquin Research, Department of Immunopathology, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam Infection and Immunity Institute, Amsterdam, Netherlands.,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, Netherlands
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21
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Piras R, Iatropoulos P, Bresin E, Todeschini M, Gastoldi S, Valoti E, Alberti M, Mele C, Galbusera M, Cuccarolo P, Benigni A, Remuzzi G, Noris M. Molecular Studies and an ex vivo Complement Assay on Endothelium Highlight the Genetic Complexity of Atypical Hemolytic Uremic Syndrome: The Case of a Pedigree With a Null CD46 Variant. Front Med (Lausanne) 2020; 7:579418. [PMID: 33224962 PMCID: PMC7670076 DOI: 10.3389/fmed.2020.579418] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/30/2020] [Indexed: 12/22/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare disease characterized by microangiopathic hemolysis, thrombocytopenia, and renal impairment and is associated with dysregulation of the alternative complement pathway on the microvascular endothelium. Outcomes have improved greatly with pharmacologic complement C5 blockade. Abnormalities in complement genes (CFH, CD46, CFI, CFB, C3, and THBD), CFH–CFHR genomic rearrangements, and anti-FH antibodies have been reported in 40–60% of cases. The penetrance of aHUS is incomplete in carriers of complement gene abnormalities; and multiple hits, including the CFH–H3 and CD46GGAAC risk haplotypes and the CFHR1*B risk allele, as well as environmental factors, contribute to disease development. Here, we investigated the determinants of penetrance of aHUS associated with CD46 genetic abnormalities. We studied 485 aHUS patients and found CD46 rare variants (RVs) in about 10%. The c.286+2T>G RV was the most prevalent (13/485) and was associated with <30% penetrance. We conducted an in-depth study of a large pedigree including a proband who is heterozygous for the c.286+2T>G RV who experienced a severe form of aHUS and developed end-stage renal failure. The father and paternal uncle with the same variant in homozygosity and six heterozygous relatives are unaffected. Flow cytometry analysis showed about 50% reduction of CD46 expression on blood mononuclear cells from the heterozygous proband and over 90% reduction in cells from the proband's unaffected homozygous father and aunt. Further genetic studies did not reveal RVs in known aHUS-associated genes or common genetic modifiers that segregated with the disease. Importantly, a specific ex vivo test showed excessive complement deposition on endothelial cells exposed to sera from the proband, and also from his mother and maternal uncle, who do not carry the c.286+2T>G RV, indicating that they share a circulating defect that results in complement dysregulation on the endothelium. These results highlight the complexity of the genetics of aHUS and indicate that CD46 deficiency may not be enough to induce aHUS. We hypothesize that the proband inherited from his mother a genetic abnormality in a complement circulating factor that has not been identified yet, which synergized with the CD46 RV in predisposing him to the aHUS phenotype.
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Affiliation(s)
- Rossella Piras
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Paraskevas Iatropoulos
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elena Bresin
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Marta Todeschini
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Sara Gastoldi
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elisabetta Valoti
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Marta Alberti
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Caterina Mele
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Miriam Galbusera
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Paola Cuccarolo
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Ariela Benigni
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Giuseppe Remuzzi
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Marina Noris
- Clinical Research Center for Rare Diseases 'Aldo e Cele Daccò,' Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
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