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Li Q, Kong X, Tian M, Wang J, Yang Z, Yu L, Liu S, Wang C, Wang X, Sun S. Clinical features of children with anti-CFH autoantibody-associated hemolytic uremic syndrome: a report of 8 cases. Ren Fail 2022; 44:1061-1069. [PMID: 35730179 PMCID: PMC9225730 DOI: 10.1080/0886022x.2022.2089167] [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: 12/04/2022] Open
Abstract
Objective To explore the clinical characteristics, treatment protocol and prognosis of children with anti-complement factor H (CFH) autoantibody (Ab)-associated hemolytic uremic syndrome (HUS). Methods Clinical data of 8 patients with anti-CFH Ab-associated HUS who were admitted to Shandong Provincial Hospital from January 2011 to December 2020 were collected retrospectively. Results The age at disease onset ranged between 5.83 and 13.5 years, with a male: female ratio of 1.67:1. The time of onset was distributed from May to June and November to December. Digestive and upper respiratory tract infections were common prodromal infections. Positivity for anti-CFH Ab and reduced C3 levels were observed among all patients. Heterozygous mutation of the CHFR5 gene (c.669del A) and homozygous loss of the CFHR1 gene [loss2(EXON:2-6)] were found in two patients. All patients received early treatment with plasma exchange and corticosteroid therapy. Six patients were given immunosuppressive agents (cyclophosphamide and/or mycophenolate mofetil) for persistent proteinuria. The follow-up period was 12–114 months. Four of 8 patients achieved complete remission, 3 achieved partial remission, and 1 died. Relapse occurred in two patients. Conclusion Children with anti-CFH Ab-associated HUS were mainly school-aged and predominantly male, with onset times of summer and winter. Digestive and upper respiratory tract infections were common prodromal infections. Plasma exchange combined with methylprednisolone pulse therapy in the acute phase and cyclophosphamide or mycophenolate mofetil treatment for maintenance can be utilized in children with anti-CFH Ab-associated HUS if eculizumab is not available.
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Affiliation(s)
- Qian Li
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
| | - Xinxin Kong
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
| | - Minle Tian
- School of Basic Medical Sciences, Shandong First Medical University, Taian, Shandong, China
| | - Jing Wang
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
| | - Zhenle Yang
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
| | - Lichun Yu
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
| | - Suwen Liu
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
| | - Cong Wang
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
| | - Xiaoyuan Wang
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
| | - Shuzhen Sun
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, P. R. China.,Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, Jinan, P. R. China
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2
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Raina R, Mangat G, Hong G, Shah R, Nair N, Abboud B, Bagga S, Sethi SK. Anti-factor H antibody and its role in atypical hemolytic uremic syndrome. Front Immunol 2022; 13:931210. [PMID: 36091034 PMCID: PMC9448717 DOI: 10.3389/fimmu.2022.931210] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/08/2022] [Indexed: 11/19/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) an important form of a thrombotic microangiopathy (TMA) that can frequently lead to acute kidney injury (AKI). An important subset of aHUS is the anti-factor H associated aHUS. This variant of aHUS can occur due to deletion of the complement factor H genes, CFHR1 and CFHR3, along with the presence of anti-factor H antibodies. However, it is a point of interest to note that not all patients with anti-factor H associated aHUS have a CFHR1/R3 deletion. Factor-H has a vital role in the regulation of the complement system, specifically the alternate pathway. Therefore, dysregulation of the complement system can lead to inflammatory or autoimmune diseases. Patients with this disease respond well to treatment with plasma exchange therapy along with Eculizumab and immunosuppressant therapy. Anti-factor H antibody associated aHUS has a certain genetic predilection therefore there is focus on further advancements in the diagnosis and management of this disease. In this article we discuss the baseline characteristics of patients with anti-factor H associated aHUS, their triggers, various treatment modalities and future perspectives.
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Affiliation(s)
- Rupesh Raina
- Department of Nephrology, Akron Children’s Hospital, Akron, OH, United States
- Department of Nephrology, Akron Nephrology Associates/Cleveland Clinic Akron General Medical Center, Akron, OH, United States
- *Correspondence: Rupesh Raina, ;
| | - Guneive Mangat
- Department of Nephrology, Akron Nephrology Associates/Cleveland Clinic Akron General Medical Center, Akron, OH, United States
| | - Gordon Hong
- Department of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Raghav Shah
- Department of Medicine, Ohio States University, Columbus, OH, United States
| | - Nikhil Nair
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Brian Abboud
- Department of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Sumedha Bagga
- Questrom School of Business, Boston University, Boston, MA, United States
| | - Sidharth Kumar Sethi
- Paediatric Nephrology & Paediatric Kidney Transplantation, Kidney and Urology Institute, Medanta, The Medicity Hospital, Gurgaon, India
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3
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Anti-Factor H Antibodies in Egyptian Children with Hemolytic Uremic Syndrome. Int J Nephrol 2021; 2021:6904858. [PMID: 34840826 PMCID: PMC8616678 DOI: 10.1155/2021/6904858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/23/2021] [Accepted: 10/26/2021] [Indexed: 12/22/2022] Open
Abstract
Background Atypical hemolytic uremic syndrome (aHUS) is an important cause of acute kidney injury in children. It is primarily caused by dysregulation of the complement alternative pathway due to genetic mutations, mainly in complement factor H genes, or due to anti-factor H autoantibodies (anti-FH), leading to uncontrolled overactivation of the complement system. Early diagnosis and treatment of autoimmune HUS (AI-HUS) is essential and leads to a favorable outcome. Methods Fifty pediatric HUS patients and 50 age- and sex-matched controls were included in the study. Patients were subjected to full history taking, clinical examination, and laboratory testing. All candidates were subjected to an assessment of anti-FH in serum by a homemade enzyme-linked immunosorbent assay technique. Results A high frequency of serum anti-FH was detected in our aHUS patients. The disease onset of AI-HUS was mainly observed in March and April, with significantly higher rates in school-aged males. All patients who started immunosuppressives early together with plasmapheresis upon detection of their anti-FH had complete renal function recovery. Conclusion The high frequency of AI-HUS revealed in Egyptian HUS children in our study highlights the importance of implementing anti-FH testing in Egypt to provide early recognition for immediate proper management, including early immunosuppressive therapy, and hence improving patient outcomes.
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4
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Wu D, Chen J, Ling C, Chen Z, Fan J, Sun Q, Meng Q, Liu X. Clinical and Genetic Characteristics of Atypical Hemolytic Uremic Syndrome in Children: A Chinese Cohort Study. Nephron Clin Pract 2021; 145:415-427. [PMID: 33873197 DOI: 10.1159/000513009] [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: 06/04/2020] [Accepted: 11/12/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Atypical hemolytic uremic syndrome (aHUS) is a rare but critical illness. To this date, few studies have reported on the disease in Chinese children. METHODS We studied a Chinese pediatric cohort to delineate the clinical characteristics, genotypes, and prognosis. Ninety-one patients with aHUS were enrolled in this study. RESULTS Fifty-nine children (64.8%) had anti-complement-factor-H autoantibody-associated aHUS (anti-CFH aHUS). Of these children, 21 (46.7%) had complement factor-H-related protein 1 (CFHR1) homozygous deletion, and most patients with CFHR1 homozygous deletion also had complement factor-H-related protein 3 (CFHR3) homozygous deletions (76.2%). Using gene sequencing of 15 candidate genes, we identified 14 genetic variants in 46 aHUS patients, including 5 pathogenic or like pathogenic variants and 9 variants of uncertain significance. The average follow-up time was 46.1 ± 28 months. Among patients with anti-CFH aHUS, there was a correlation between CFHR1 homozygous deletion and patients with persistent proteinuria (odds ratio [OR] 6.954, 95% confidence interval [CI] 1.033-46.821, p = 0.046). As of the last follow-up, ESRD or deaths occurred in 3.6% of the children with anti-CFH aHUS and 26.7% of children with aHUS who were negative for anti-CFH. CONCLUSIONS Anti-complement-factor-H antibody positivity is the main cause of morbidity in Chinese children with aHUS. There may be a correlation between CFHR1 homozygous deletion and persistent proteinuria. Comprehensive assessment of anti-CFH antibodies and genetic variants is essential for the management of aHUS children.
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Affiliation(s)
- Dan Wu
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Jiahui Chen
- Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Chen Ling
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Zhi Chen
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Jianfeng Fan
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Qiang Sun
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Qun Meng
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Xiaorong Liu
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, Beijing, China
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5
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Zhang Y, Ghiringhelli Borsa N, Shao D, Dopler A, Jones MB, Meyer NC, Pitcher GR, Taylor AO, Nester CM, Schmidt CQ, Smith RJH. Factor H Autoantibodies and Complement-Mediated Diseases. Front Immunol 2020; 11:607211. [PMID: 33384694 PMCID: PMC7770156 DOI: 10.3389/fimmu.2020.607211] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/05/2020] [Indexed: 12/25/2022] Open
Abstract
Factor H (FH), a member of the regulators-of-complement-activation (RCA) family of proteins, circulates in human plasma at concentrations of 180–420 mg/L where it controls the alternative pathway (AP) of complement in the fluid phase and on cell surfaces. When the regulatory function of FH is impaired, complement-mediated tissue injury and inflammation occur, leading to diseases such as atypical hemolytic uremic syndrome (a thrombotic microangiopathy or TMA), C3 glomerulopathy (C3G) and monoclonal gammopathy of renal significance (MGRS). A pathophysiological cause of compromised FH function is the development of autoantibodies to various domains of the FH protein. FH autoantibodies (FHAAs) are identified in 10.9% of patients with aHUS, 3.2% of patients with C3G, and rarely in patients with MGRS. The phenotypic variability of FHAA-mediated disease reflects both the complexity of FH and the epitope specificity of FHAA for select regions of the native protein. In this paper, we have characterized FHAA epitopes in a large cohort of patients diagnosed with TMA, C3G or MGRS. We explore the epitopes recognized by FHAAs in these diseases and the association of FHAAs with the genetic deletion of both copies of the CFHR1 gene to show how these disease phenotypes are associated with this diverse spectrum of autoantibodies.
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Affiliation(s)
- Yuzhou Zhang
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Nicolo Ghiringhelli Borsa
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Dingwu Shao
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Arthur Dopler
- Institute of Pharmacology of Natural Products & Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Michael B Jones
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Nicole C Meyer
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Gabriella R Pitcher
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Amanda O Taylor
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Carla M Nester
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products & Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
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6
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Complement-mediated kidney diseases. Mol Immunol 2020; 128:175-187. [DOI: 10.1016/j.molimm.2020.10.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/16/2020] [Accepted: 10/19/2020] [Indexed: 12/19/2022]
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7
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Li X, Hao Z, Liu X, Li W. Deficiency of Mouse FHR-1 Homolog, FHR-E, Accelerates Sepsis, and Acute Kidney Injury Through Enhancing the LPS-Induced Alternative Complement Pathway. Front Immunol 2020; 11:1123. [PMID: 32636836 PMCID: PMC7316958 DOI: 10.3389/fimmu.2020.01123] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/07/2020] [Indexed: 11/26/2022] Open
Abstract
Alternative complement pathway (AP) plays an important role in the development of sepsis, which is life threatening. Deficiency of factor H-related protein 1 (FHR-1), which is a regulator of AP, has been considered as a susceptible factor for atypical hemolytic uremic syndrome (aHUS) and other types of nephropathy when an inducer such as infection exists. However, the underlying mechanism of the disease development is largely unknown. There is no report on CFHR1 gene knockout in any animal infection model and its function in vivo is still unclear. Here, a Cfhr1 knockout mouse was generated for investigating AP in sepsis and sepsis-induced acute kidney injury (AKI). We found that murine FHR-1 homolog (FHR-E) deficiency enhanced lipopolysaccharide (LPS)-induced AP activation both in vitro and in vivo and that Cfhr1 knockout mice exhibited more severe sepsis and AKI in response to LPS challenge. These results indicated that FHR-E deficiency promoted LPS-induced sepsis and AKI through AP over-activation, providing a mouse model for studying AP regulation and sepsis. This study revealed the function of FHR-E in vivo, which may further provide hints to the pathogenesis of FHR-1 deficiency-related diseases by enhancing LPS-induced AP activation.
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Affiliation(s)
- Xiangru Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Beijing, China.,Genetics and Birth Defects Control Center, National Center for Children's Health, Beijing, China
| | - Zhenhua Hao
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Beijing, China.,Genetics and Birth Defects Control Center, National Center for Children's Health, Beijing, China
| | - Xiaorong Liu
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, China.,MOE Key Laboratory of Major Diseases in Children, Beijing, China.,Genetics and Birth Defects Control Center, National Center for Children's Health, Beijing, China
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8
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Bagga A, Khandelwal P, Mishra K, Thergaonkar R, Vasudevan A, Sharma J, Patnaik SK, Sinha A, Sethi S, Hari P, Dragon-Durey MA. Hemolytic uremic syndrome in a developing country: Consensus guidelines. Pediatr Nephrol 2019; 34:1465-1482. [PMID: 30989342 DOI: 10.1007/s00467-019-04233-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 01/06/2019] [Accepted: 03/07/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Hemolytic uremic syndrome (HUS) is a leading cause of acute kidney injury in children. Although international guidelines emphasize comprehensive evaluation and treatment with eculizumab, access to diagnostic and therapeutic facilities is limited in most developing countries. The burden of Shiga toxin-associated HUS in India is unclear; school-going children show high prevalence of anti-factor H (FH) antibodies. The aim of the consensus meeting was to formulate guidelines for the diagnosis and management of HUS in children, specific to the needs of the country. METHODS Four workgroups performed literature review and graded research studies addressing (i) investigations, biopsy, genetics, and differential diagnosis; (ii) Shiga toxin, pneumococcal, and infection-associated HUS; (iii) atypical HUS; and (iv) complement blockade. Consensus statements developed by the workgroups were discussed during a consensus meeting in March 2017. RESULTS An algorithm for classification and evaluation was developed. The management of Shiga toxin-associated HUS is supportive; prompt plasma exchanges (PEX) is the chief therapy in patients with atypical HUS. Experts recommend that patients with anti-FH-associated HUS be managed with a combination of PEX and immunosuppressive medications. Indications for eculizumab include incomplete remission with plasma therapy, life-threatening features, complications of PEX or vascular access, inherited defects in complement regulation, and recurrence of HUS in allografts. Priorities for capacity building in regional and national laboratories are highlighted. CONCLUSIONS Limited diagnostic capabilities and lack of access to eculizumab prevent the implementation of international guidelines for HUS in most developing countries. We propose practice guidelines for India, which will perhaps be applicable to other developing countries.
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Affiliation(s)
- Arvind Bagga
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Priyanka Khandelwal
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Kirtisudha Mishra
- Department of Pediatrics, Chacha Nehru Bal Chikitsalya, New Delhi, India
| | - Ranjeet Thergaonkar
- Department of Pediatrics, Indian Naval Hospital Ship, Kalyani, Visakhapatnam, India
| | - Anil Vasudevan
- Department of Pediatric Nephrology, St. Johns Medical College and Hospital, Bengaluru, India
| | - Jyoti Sharma
- Department of Pediatrics, KEM Hospital, Pune, India
| | - Saroj Kumar Patnaik
- Department of Pediatrics, Army Hospital Research & Referral, New Delhi, India
| | - Aditi Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Sidharth Sethi
- Department of Nephrology, Medanta Hospital, New Delhi, India
| | - Pankaj Hari
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Marie-Agnes Dragon-Durey
- Laboratory of Immunology, Hopital Europeen Georges Pompidou, INSERM UMRS 1138, Paris Descartes University, Paris, France
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9
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Bhasym A, Bhakuni T, Guchhait P. Elevated surface-bound complement FH alters the function of platelets and monocytes in FHR1/3 null healthy individuals. Blood Cells Mol Dis 2019; 79:102349. [PMID: 31357175 DOI: 10.1016/j.bcmd.2019.102349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 07/14/2019] [Accepted: 07/14/2019] [Indexed: 10/26/2022]
Abstract
Complement factor H (FH) and FH-related proteins (FHRs), structurally similar proteins are involved in the regulation of complement activation. Homozygous deletion of FHR 1 and 3 proteins (FHR1/3-/-) is known as a risk factor for disorders such as aHUS and SLE, characterised by thrombo-inflammatory complications. Interestingly, FHR1/3-/- genotype also exists as polymorphism in healthy population of various ethnicities around the world including 8-10% Indians. In an effort to understand the functional role of this polymorphism, we describe in this study an elevated surface-bound FH on platelets and monocytes, but not other blood cells in FHR1/3 -/- healthy individuals. The FHR1/3-/- platelets displayed diminish ability to form aggregates in response to agonists in vitro. The FHR1/3-/- monocytes displayed elevated secretion of TNFα, IL1β, IL6 and IL10 in response to TLR ligands. However, exogenous FH limits platelet aggregates formation as well as cytokine secretion in monocytes. Therefore, observations together suggest a differential regulation of platelets and monocytes by FH-FHR1/3 axis in healthy individuals. While these findings will need more detailed investigation, it is clear that the connection between FH-FHR axis and thrombo-inflammatory complications is likely to be complex in diseases including aHUS and SLE, and provide interesting new directions for future study.
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Affiliation(s)
- Angika Bhasym
- Disease Biology Laboratory, Regional Centre for Biotechnology, National Capital Region Biotech Science Cluster, Faridabad, India
| | - Teena Bhakuni
- Disease Biology Laboratory, Regional Centre for Biotechnology, National Capital Region Biotech Science Cluster, Faridabad, India
| | - Prasenjit Guchhait
- Disease Biology Laboratory, Regional Centre for Biotechnology, National Capital Region Biotech Science Cluster, Faridabad, India.
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10
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Puraswani M, Khandelwal P, Saini H, Saini S, Gurjar BS, Sinha A, Shende RP, Maiti TK, Singh AK, Kanga U, Ali U, Agarwal I, Anand K, Prasad N, Rajendran P, Sinha R, Vasudevan A, Saxena A, Agarwal S, Hari P, Sahu A, Rath S, Bagga A. Clinical and Immunological Profile of Anti-factor H Antibody Associated Atypical Hemolytic Uremic Syndrome: A Nationwide Database. Front Immunol 2019; 10:1282. [PMID: 31231391 PMCID: PMC6567923 DOI: 10.3389/fimmu.2019.01282] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/20/2019] [Indexed: 12/12/2022] Open
Abstract
Background: Atypical hemolytic uremic syndrome (aHUS), an important cause of acute kidney injury (AKI), is characterized by dysregulation of the alternative complement pathway. Autoantibodies to factor H (FH), a chief regulator of this pathway, account for a distinct subgroup. While high anti-FH titers predict relapse, they do not correlate well with disease activity and their functional characterization is required. Methods: Of 781 patients <18-year-old of aHUS in the nationwide database from 2007 to 2018, 436 (55.8%) had anti-FH antibodies. Clinical features and outcome of patients managed in the last 6-year (n = 317) were compared to before (n = 119). In plasma samples of 44 patients, levels of serial circulating FH immune complexes (CIC), free FH, soluble terminal complement complex (sC5b-9), sheep red blood cell (SRBC) lysis and epitope specificity (n = 8) were examined. Functional renal reserve, ambulatory hypertension, left ventricular hypertrophy (LVH), and proteinuria were evaluated in a subset. Results: Patients presented with markedly elevated anti-FH titers (10,633.2 ± 998.5 AU/ml). Management varied by center, comprising plasma exchange (PEX; 77.5%) and immunosuppression (73.9%). Patients managed in the last 6-year showed better renal survival at mean 28.5 ± 27.3 months (log rank P = 0.022). Mean anti-FH titers stayed 700–1,164 AU/ml during prolonged follow-up, correlating with CIC. Patients with relapse had lower free-FH during remission [Generalized estimating equations (GEE), P = 0.001]; anti-FH levels ≥1,330 AU/ml and free FH ≤440 mg/l predicted relapse (hazards ratio, HR 6.3; P = 0.018). Epitope specificity was similar during onset, remission and relapse. Antibody titer ≥8,000 AU/ml (HR 2.23; P = 0.024), time to PEX ≥14 days (HR 2.09; P = 0.071) and PEX for <14 days (HR 2.60; P = 0.017) predicted adverse renal outcomes. Combined PEX and immunosuppression improved long-term outcomes (HR 0.37; P = 0.026); maintenance therapy reduced risk of relapses (HR 0.11; P < 0.001). At 4.4±2.5 year, median renal reserve was 15.9%; severe ambulatory, masked and pre-hypertension were found in 38, 30, and 18%, respectively. Proteinuria and LVH occurred in 58 and 28% patients, respectively. Conclusion: Prompt recognition and therapy with PEX and immunosuppression, is associated with satisfactory outcomes. Free-FH predicts early relapses in patients with high anti-FH titers. A significant proportion of impaired functional reserve, ambulatory hypertension, proteinuria and LVH highlight the need for vigilant long-term follow-up.
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Affiliation(s)
- Mamta Puraswani
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Priyanka Khandelwal
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Himanshi Saini
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Savita Saini
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Bahadur Singh Gurjar
- Immuno Biology Laboratory II, National Institute of Immunology, New Delhi, India
| | - Aditi Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | | | | | | | - Uma Kanga
- Department of Transplant Immunology and Immunogenetics, All India Institute of Medical Sciences, New Delhi, India
| | - Uma Ali
- Department of Pediatrics, BJ Wadia Hospital for Children, Mumbai, India
| | - Indira Agarwal
- Department of Pediatrics, Christian Medical College, Vellore, India
| | - Kanav Anand
- Division of Pediatric Nephrology, Sir Ganga Ram Hospital, New Delhi, India
| | - Narayan Prasad
- Department of Nephrology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Padmaraj Rajendran
- Department of Pediatric Nephrology, Institute of Child Health and Hospital for Children, Madras Medical College, Chennai, India
| | - Rajiv Sinha
- Department of Pediatrics, Institute of Child Health, Kolkata, India
| | - Anil Vasudevan
- Department of Pediatric Nephrology, St. Johns Medical College and Hospital, Bengaluru, India
| | - Anita Saxena
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, India
| | - Sanjay Agarwal
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Pankaj Hari
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Arvind Sahu
- National Centre for Cell Science, Pune, India
| | - Satyajit Rath
- National Centre for Cell Science, Pune, India.,Translational Health Science and Technology Institute, Faridabad, India
| | - Arvind Bagga
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
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Altered Peripheral Blood Leucocyte Phenotype and Responses in Healthy Individuals with Homozygous Deletion of FHR1 and FHR3 Genes. J Clin Immunol 2019; 39:336-345. [DOI: 10.1007/s10875-019-00619-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/26/2019] [Indexed: 01/10/2023]
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